Charge Conduction Properties of a Parallel-stranded DNA G-quadruplex: Implications for Chromosomal Oxidative Damage

Biochemistry. Jul, 2009  |  Pubmed ID: 19530739

The charge-flow properties and concomitant guanine damage patterns of a number of intermolecular and wholly parallel-stranded DNA G-quadruplexes were investigated. The DNA constructs were structurally well-defined and consisted of the G-quadruplex sandwiched and stacked between two Watson-Crick base-paired duplexes. Such duplex-quadruplex-duplex constructs were designed to minimize torsional stress as well as steric crowding at the duplex-quadruplex junctions. When anthraquinone was used to induce charge flow within the constructs, it was found that the quadruplex served both as a sink and as a moderately good conductor of electron holes, relative to DNA duplexes. Most strikingly, the quadruplex suffered very little charge-flow generated oxidative damage relative to guanines in the duplex regions and, indeed, to guanines in antiparallel quadruplexes reported in prior studies. It is likely that these differences result from a combination of steric and electronic factors. A biological conclusion that may be drawn from these data is that if, as anticipated, G-quadruplex structures form in vivo at the telomeres and other loci in eukaryotic chromosomes, their ability to serve as protective sinks against chromosomal oxidative damage may depend on their specific character and topology. From a separate perspective, our results on the conduction properties of duplex-quadruplex-duplex DNA composites suggest the utility of G-quadruplexes as junction modules in the construction of DNA-based biosensors and nanocircuitry.

Choosing Hamsters but Not Rats As a Model for Studying Plasma Cholesterol-lowering Activity of Functional Foods

Molecular Nutrition & Food Research. Jul, 2009  |  Pubmed ID: 19536872

Rats and hamsters are commonly used rodents to test the efficacy of cholesterol-lowering functional foods. In general, a diet containing 1% cholesterol for rats whereas a diet containing 0.1% cholesterol for hamsters is used to induce the hypercholesterolemia. The present study was carried out to compare hamsters with rats as a hypercholesterolemia model. Golden Syrian hamsters and Sprague Dawley rats were randomly divided into four groups and fed one of the four diets containing 0-0.9% cholesterol. Results demonstrated that serum total cholesterol (TC) in hamsters was raised 73-81% higher than that in rats fed the same cholesterol diets. Unlike rats in which HDL-C accounted very little for serum TC, the lipoprotein profile in hamsters was closer to that in humans. We investigated interaction of higher cholesterol diets with 3-hydroxy-3-methylglutary-CoA (HMG-CoA) reductase, low-density lipoprotein receptor (LDL-R) and cholesterol-7alpha-hydroxylase (CYP7A1), sterol regulatory element binding protein-2 (SREBP-2), and liver X receptor (LXR-alpha). Results showed hamsters and rats metabolized cholesterol differently. In view that hamsters synthesize and excrete cholesterol and bile acids in a manner similar to that in humans, it is concluded that hamsters but not rats shall be chosen as a model to study efficacy of cholesterol-lowering functional foods.

Characterization of the H5N1 Highly Pathogenic Avian Influenza Virus Derived from Wild Pikas in China

Journal of Virology. Sep, 2009  |  Pubmed ID: 19553321

The highly pathogenic H5N1 avian influenza virus emerged from China in 1996 and has spread across Eurasia and Africa, with a continuous stream of new cases of human infection appearing since the first large-scale outbreak among migratory birds at Qinghai Lake. The role of wild birds, which are the natural reservoirs for the virus, in the epidemiology of the H5N1 virus has raised great public health concern, but their role in the spread of the virus within the natural ecosystem of free-ranging terrestrial wild mammals remains unclear. In this study, we investigated H5N1 virus infection in wild pikas in an attempt to trace the circulation of the virus. Seroepidemiological surveys confirmed a natural H5N1 virus infection of wild pikas in their native environment. The hemagglutination gene of the H5N1 virus isolated from pikas reveals two distinct evolutionary clades, a mixed/Vietnam H5N1 virus sublineage (MV-like pika virus) and a wild bird Qinghai (QH)-like H5N1 virus sublineage (QH-like pika virus). The amino acid residue (glutamic acid) at position 627 encoded by the PB2 gene of the MV-like pika virus was different from that of the QH-like pika virus; the residue of the MV-like pika virus was the same as that of the goose H5N1 virus (A/GS/Guangdong [GD]/1/96). Further, we discovered that in contrast to the MV-like pika virus, which is nonpathogenic to mice, the QH-like pika virus is highly pathogenic. To mimic the virus infection of pikas, we intranasally inoculated rabbits, a species closely related to pikas, with the H5N1 virus of pika origin. Our findings first demonstrate that wild pikas are mammalian hosts exposed to H5N1 subtype avian influenza viruses in the natural ecosystem and also imply a potential transmission of highly pathogenic avian influenza virus from wild mammals into domestic mammalian hosts and humans.

Combining Angiogenic Gene and Stem Cell Therapies for Myocardial Infarction

The Journal of Gene Medicine. Sep, 2009  |  Pubmed ID: 19554624

Transplantation of stem cells from various sources into infarcted hearts has the potential to promote myocardial regeneration. However, the regenerative capacity is limited partly as a result of the low survival rate of the transplanted cells in the ischemic myocardium. In the present study, we tested the hypothesis that combining cell and angiogenic gene therapies would provide additive therapeutic effects via co-injection of bone marrow-derived mesenchymal stem cells (MSCs) with an adeno-associated viral vector (AAV), MLCVEGF, which expresses vascular endothelial growth factor (VEGF) in a cardiac-specific and hypoxia-inducible manner.

[Papillary Glioneuronal Tumor: Report of a Case]

Zhonghua Bing Li Xue Za Zhi Chinese Journal of Pathology. Mar, 2009  |  Pubmed ID: 19575860

Effect of Adrenotensin on Cell Proliferation is Mediated by Angiotensin II in Cultured Rat Mesangial Cells

Acta Pharmacologica Sinica. Aug, 2009  |  Pubmed ID: 19597528

Both adrenomedullin (ADM) and adrenotensin (ADT) are derived from the same propeptide precursor, and both act as circulating hormones and local paracrine mediators with multiple biological activities. Compared with ADM, little is known about how ADT achieves its functions. In the present study, we investigated the effect of ADT on cell proliferation and transforming growth factor-beta (TGF-beta) secretion in cultured renal mesangial cells (MCs) and determined whether angiotensin II (Ang II) was involved in mediating this process.

[Genomic Sequence of a New Serotype Duck Hepatitis Virus]

Wei Sheng Wu Xue Bao = Acta Microbiologica Sinica. Mar, 2009  |  Pubmed ID: 19623953

A strain of highly pathogenic duck hepatitis virus was isolated in south China from a Pekin duck flock in 1999. No cross reaction with type 1 and 3 duck hepatitis virus was found by serum neutralization. We suggested the strain should be classified as a new serotype of duck hepatitis virus and named it as DHV-N G strain in our previous study. We wanted to reveal the evolution of this virus in molecular level and gene sequence differences between it and DHV-1 strains.

Hydrolytic Cleavage of DNA by Urea-bridged Macrocyclic Polyamines

European Journal of Medicinal Chemistry. Dec, 2009  |  Pubmed ID: 19640615

Novel bis-cyclen derivative A with urea, mono-cyclen derivative B with urea and amino acid urea C were synthesized as DNA cleavage agents. The structures of these new compounds were identified by MS and (1)H NMR spectroscopy. The catalytic activities on DNA cleavage of these compounds were subsequently studied, and results show that A is a much better catalyst in DNA cleavage process than that of B and C. The effects of reaction time and catalyst concentration were also investigated. The results indicate that A can catalyze the cleavage of supercoiled DNA (pUC 19 plasmid DNA) to nicked DNA under physiological conditions with high yields (nearly 100%) via a hydrolytic mechanism.

The Effect of an Amino-acid Bridge on Binding Affinity and Cleavage Efficiency of Pyrenyl-macrocyclic Polyamine Conjugates Toward DNA

Chemistry & Biodiversity. Aug, 2009  |  Pubmed ID: 19697347

A series of pyrenyl-macrocyclic polyamines 5a-5c have been prepared and characterized. Their DNA-cleavage properties were examined under physiological conditions. Without the presence of other additives, the DNA cleavage ability of 5a-5c showed the order of 5c>5a>5b. Absorption and fluorescence experiments showed the binding affinity of 5a-5c to DNA. The interactions of 5a-5c with CT-DNA indicated that the DNA binding ability followed an order according to their cleavage efficiency. All the results indicated that the structures of amino-acid bridge in the ligands may affect the DNA binding and cleavage ability. The cleavage-mechanism studies indicated that singlet oxygen and superoxide free radicals were involved in the catalytic DNA cleavage process.

Nosocomial Transmission of Undetected, Imported Measles in Taiwan, 2008

Infection Control and Hospital Epidemiology : the Official Journal of the Society of Hospital Epidemiologists of America. Oct, 2009  |  Pubmed ID: 19737092

Black Tea Theaflavins Extend the Lifespan of Fruit Flies

Experimental Gerontology. Dec, 2009  |  Pubmed ID: 19770032

Black tea extract (BTE) is a mixture of epicatechins and theaflavins. The present study investigated the effect of BTE on the lifespan of Drosophila melanogaster. Results showed the mean lifespan was significantly extended from 51 to 56days upon BTE treatment. Gene expression of superoxide dismutase (SOD1 and SOD2), catalase (CAT), and methuselah (MTH) was characterized by an increase in young and then a decrease in aged fruit flies. Higher gene expression of SOD1 and CAT was observed in the BTE-treated group than the control flies. However, BTE exerted a minimal effect on the expression of SOD2 and MTH genes. Dietary fat could induce oxidative stress and shorten the maximum lifespan to 15days, while addition of 10mg/ml BTE into diet extended it to 28days. Paraquat and H(2)O(2) challenge tests demonstrated that BTE prolonged the survival time only for Oregon-R wild type flies but not for SOD(n108) or Cat(n1) mutants. This suggests that the lifespan-prolonging activity of BTE is mediated at least in part through SOD and CAT.

Stable Non-synonymous Substitutions on NS Gene (NS1 and NS2 Proteins) of Qinghai Lake H5N1 Influenza Virus (Clade 2.2) After Successive Passages in Muscovy Ducks

Science in China. Series C, Life Sciences / Chinese Academy of Sciences. Sep, 2009  |  Pubmed ID: 19802744

Although worldwide concern has been raised since the large-scale outbreak of highly pathogenic avian influenza in wild birds at Qinghai Lake, China in 2005, the factors responsible for the ability to kill waterfowl remain unclear. The why and how questions of the H5N1 virus species-jump into its reservoir host need to be answered. In this report we test the pathogenicity and adaptation of Qinghai Lake (Clade 2.2) isolate to Muscovy ducks for further understanding of this virus. The isolate was highly pathogenic in ducks and retained its high pathogenicity even after 20 generations of passage in ducks. During the process of serial passages, only the NS gene developed non-synonymous substitutions, which caused two mutations in NS1 protein (Val23Ala and Leu207Pro) and one in NS2 (Phe55Leu). These mutations persisted immutably through all subsequent passages and the pathogenicity remained high, implying that highly pathogenic H5N1 virus remains stable in aquatic birds through oral transmission. Although the exact functions of these mutations are not known, our results provide an important foundation for further understanding the characteristics of the Qinghai Lake isolates.

Electrically Conductive and Optically Active Porous Silicon Nanowires

Nano Letters. Dec, 2009  |  Pubmed ID: 19807130

We report the synthesis of vertical silicon nanowire array through a two-step metal-assisted chemical etching of highly doped n-type silicon (100) wafers in a solution of hydrofluoric acid and hydrogen peroxide. The morphology of the as-grown silicon nanowires is tunable from solid nonporous nanowires, nonporous/nanoporous core/shell nanowires, to entirely nanoporous nanowires by controlling the hydrogen peroxide concentration in the etching solution. The porous silicon nanowires retain the single crystalline structure and crystallographic orientation of the starting silicon wafer and are electrically conductive and optically active with visible photoluminescence. The combination of electronic and optical properties in the porous silicon nanowires may provide a platform for novel optoelectronic devices for energy harvesting, conversion, and biosensing.

Specific Peptide Regulated Synthesis of Ultrasmall Platinum Nanocrystals

Journal of the American Chemical Society. Nov, 2009  |  Pubmed ID: 19831348

We demonstrate the rational synthesis of monodisperse ultrasmall platinum (Pt) nanocrsytals (NCs), in aqueous solution at room temperature, with specifically selected peptide molecules. The specific Pt-binding peptide, selected using a phage display technique, can function as a stabilizer to regulate Pt crystal nucleation and growth and, therefore, control both the morphology and size of the final Pt NCs. Uniform near-spherical Pt NCs with sizes ranging from 1.73 to 3.54 nm were achieved with a very narrow size distribution. The peptide-stabilized Pt NCs can be dispersed well in water for months. It was also demonstrated that the strong binding of peptides to the Pt NC surface is reversible by either pH modulation or peptide photolysis.

Preparation and Evaluation of N-caproyl Chitosan Nanoparticles Surface Modified with Glycyrrhizin for Hepatocyte Targeting

Drug Development and Industrial Pharmacy. Nov, 2009  |  Pubmed ID: 19832635

The development of an efficient targeted drug delivery system into cells is an important subject for the advancement of drug carriers. In this study, a novel hepatocyte-targeted delivery system with glycyrrhizin (GL) surface modification based on N-caproyl chitosan (CCS) has been developed.

Effect of IPP5, a Novel Inhibitor of PP1, on Apoptosis and the Underlying Mechanisms Involved

Biotechnology and Applied Biochemistry. Dec, 2009  |  Pubmed ID: 19874272

Genes encoding apoptosis-inducing proteins are postulated to be candidate tumour suppressors. The identification of such proteins may benefit the early diagnosis and therapy of tumours. In the present study, we characterized the function of a novel human BMSC (bone marrow stromal cell)-derived protein {IPP5 [inhibitor-5 of PP1 (protein phosphatase 1)]} by large-scale random sequencing of a human BMSC cDNA library. hIPP5 (human IPP5) cDNA encodes a protein of 116 amino acid residues, which shares high homology with human PPI-1 (inhibitor-1 of PP1). The effect of IPP5 on apoptosis and the underlying molecular mechanisms were investigated by overexpression of IPP5 in HeLa cells, a human cervical carcinoma cell line. Our results showed that overexpression of active mutant IPP5 inhibited anchorage-dependent growth and induced apoptosis in HeLa cells, which may be attributed to the up-regulation of p21(waf/cip1) (a 21 kDa cell-cycle regulatory protein), p53 and Bcl-2-antagonist/killer, and down-regulation of Bcl-2 and Bcl-X(L). We also showed that the expression of active mutant IPP5 in HeLa cells was further enhanced on TNF (tumour necrosis factor) treatment and overexpression of active mutant IPP5 sensitized HeLa cells to TNF-induced JNK (c-Jun N-terminal kinase) and p38 activation as well as TNF-mediated apoptosis. Thus overexpression of active mutant IPP5 may increase cell susceptibility to TNF-induced apoptosis by the activation of p38 and JNK pathways. In addition, IPP5 active mutant could interact with PP1alpha as demonstrated by the co-precipitation assay.

Quantification and Controllability Study of Minimally Invasive Exothermic Chemo-ablation Therapy for Tumor Ablation

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2009  |  Pubmed ID: 19963802

The recently proposed exothermic chemical reaction based tumor hyperthermia method presented a new way of realizing truly minimally invasive treatment for tumor. This method utilizes heat generated from the reaction between acid and alkali solutions to allow for tumor ablation. Successful clinical implementation of this method requires a clearer understanding and quantification of the ablation area such that a more controllable operation can be made. A number of in-vitro and in-vivo experiments are designed to examine the features of thermal chemo-ablation therapy which include micro and macro characteristics of ablated tissue and temperature change during the ablation process. A Quantitative study on the relationship between velocity and ablation volume as well as a Graphical User Interface in Matlab for computerized ablation area analysis are also presented in this article. We present in here two instrument designs for thermal chemo-ablation and have completed the prototype design for the injection pump which has been tested and successfully applied in ex-vivo and vivo experiments.

Protein Nanocapsule Weaved with Enzymatically Degradable Polymeric Network

Nano Letters. Dec, 2009  |  Pubmed ID: 19995089

Target proteins can be functionally encapsulated using a cocoon-like polymeric nanocapsule formed by interfacial polymerization. The nanocapsule is cross-linked by peptides that can be proteolyzed by proteases upon which the protein cargo is released. The protease-mediated degradation process can be controlled in a spatiotemporal fashion through modification of the peptide cross-linker with photolabile moieties. We demonstrate the utility of this approach through the cytoplasmic delivery of the apoptosis inducing caspase-3 to cancer cells.

[Mechanism and Problem of Amifostine in Treating Myelodysplastic Syndromes]

Zhongguo Shi Yan Xue Ye Xue Za Zhi / Zhongguo Bing Li Sheng Li Xue Hui = Journal of Experimental Hematology / Chinese Association of Pathophysiology. Dec, 2009  |  Pubmed ID: 20030955

Myelodysplastic syndrome (MDS) is one of the most prevalent haematological malignancies originating from haemopoietic stem/progenitor cells. MDS characterized by morbid haematopoiesis of bone marrow and peripheral blood cell reduction and mainly occurs in the elders. The dangerous factors of MDS include chemotherapy, radiotherapy, benzene, other organic solvent, immune depressants and so on. Following the recent progress of medical sciences, a large number of new regimens of chemotherapy, radiotherapy and immune therapy against carcinomas generate and lead the development of therapeutics for malignancies. It is worried that the incidence of MDS still increases year by year and the patient age becomes younger. Although many agents are used to MDS, curative effect is not as good as expect. Amifostine, a kind of pancytoprotector also used in treatment of MDS. This review summarizes the mechanism of amifostine in MDS therapy which possesses a challenge binding with the current related investigations.

[Individualizing Treatment of Refractory and Relapsed ITP in Adults and Its Development of Study]

Zhongguo Shi Yan Xue Ye Xue Za Zhi / Zhongguo Bing Li Sheng Li Xue Hui = Journal of Experimental Hematology / Chinese Association of Pathophysiology. Dec, 2009  |  Pubmed ID: 20030958

Idiopathic thrombocytopenic purpura (ITP) is a common hematological disease. It bleeds with peripheral blood platelet reduction as the main clinical manifestation, and manifests a chronic history in adult people. 11% - 35% ITP patients develop into a refractory course, which may be related with gene polymorphisms. There is currently no consensus on how best to manage refractory/relapsed ITP. In part, this reflects the need for individualized treatment due to the patients' requirements and their responsiveness to therapies. The objective of this review is to provide a clinically useful guide to current management strategies. This article summarizes all the treatment for refractory ITP, and highlights new therapies, including the anti-CD20 antibody, thrombopoietic agents, TPO receptor agonist and HSCT. The pancytoprotector shows good effect in the treatment of refractory and relapsed ITP in China. In a word, to give different treatments individually is most important.

[Expression and Mutations of PIK3CA Gene in Hepatocellular Carcinomas]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Dec, 2009  |  Pubmed ID: 20034918

To investigate the expression and mutation of PIK3CA gene in hepatocellular carcinomas (HCC).

Binary Molecular Networks: Small 1/2010

Small (Weinheim an Der Bergstrasse, Germany). Dec, 2009  |  Pubmed ID: 20039364

[Effect of Methylene Chloride Upon Hepatic Ischemic Reperfusion Injury]

Zhonghua Yi Xue Za Zhi. Dec, 2009  |  Pubmed ID: 20193372

To investigate the effects and mechanisms of methylene chloride (MC) in hepatic ischemic reperfusion injury.

Red Yeast Rice Increases Excretion of Bile Acids in Hamsters

Biomedical and Environmental Sciences : BES. Aug, 2009  |  Pubmed ID: 19950521

To investigate the hypocholesterolemic activity of red yeast rice (RYR) and its underlying mechanism.

Adenosine 5'-triphosphate Stimulates the Increase of TGF-beta1 in Rat Mesangial Cells Under High-glucose Conditions Via Reactive Oxygen Species and ERK1/2

Acta Pharmacologica Sinica. Dec, 2009  |  Pubmed ID: 19960006

To investigate the role of adenosine 5'-triphosphate (ATP)-induced generation of reactive oxygen species (ROS) and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in the production of transforming growth factor-beta1 (TGF-beta1) in cultured rat glomerular mesangial cells under high-glucose conditions.

Human Urotensin II in Internal Mammary and Radial Arteries of Patients Undergoing Coronary Surgery

Vascular Pharmacology. Jan-Feb, 2010  |  Pubmed ID: 19962453

Internal mammary (IMA) and radial artery (RA) have different incidence of vasospasm and long-term patency rates in arterial grafting. We compared the vasoreactivity of human urotensin II (hU-II) and its receptor with mechanism investigations in IMA and RA.

Bone Morphogenic Protein-4 Impairs Endothelial Function Through Oxidative Stress-dependent Cyclooxygenase-2 Upregulation: Implications on Hypertension

Circulation Research. Oct, 2010  |  Pubmed ID: 20724703

Bone morphogenic protein (BMP)4 can stimulate superoxide production and exert proinflammatory effects on the endothelium. The underlying mechanisms of how BMP4 mediates endothelial dysfunction and hypertension remain elusive.

MicroRNA-21 Promotes the Cell Proliferation, Invasion and Migration Abilities in Ovarian Epithelial Carcinomas Through Inhibiting the Expression of PTEN Protein

International Journal of Molecular Medicine. Dec, 2010  |  Pubmed ID: 21042775

Ovarian cancer, especially epithelial ovarian cancer (EOC), which accounts for 90% of ovarian cancer, continues to be the leading cause of death among gynecological malignancies. However, the factors associated with its malignant biological behavior are still poorly understood. Accumulating evidence suggests that microRNAs (miRNAs), regulating diverse biological processes, may play an important role in tumorigenesis and development. miR-21 has been frequently observed to be aberrantly overexpressed in various tumors. Using real-time PCR, we confirmed that miR-21 was significantly overexpressed in human EOC tissues and cell lines. The overexpression of miR-21 correlated with histological differentiation, clinicopathological stage, and lymph node metastasis, and we showed that knockdown of miR-21 by an inhibitor caused a significant reduction in cell proliferation and decrease in cell migration and invasion abilities. Furthermore, we demonstrated that knockdown of miR-21 significantly increased the expression of PTEN, a known tumor suppressor in ovarian cancer. Collectively, our findings suggest miR-21 may be important in the initiation and progression of EOC as an oncomiR, likely through regulating PTEN.

One Dimensional Molecular Dipole Chain Arrays on Graphite Via Nanoscale Phase Separation

Chemical Communications (Cambridge, England). Dec, 2010  |  Pubmed ID: 21052573

Molecular dipole chain arrays of chloroaluminium phthalocyanine (ClAlPc) on the graphite surface have been investigated by scanning tunneling microscopy. The inter-chain spacing can be tuned by the co-adsorption of di-indenoperylene (DIP) via nanoscale phase separation.

Association Mapping of Local Climate-sensitive Quantitative Trait Loci in Arabidopsis Thaliana

Proceedings of the National Academy of Sciences of the United States of America. Dec, 2010  |  Pubmed ID: 21078970

Flowering time (FT) is the developmental transition coupling an internal genetic program with external local and seasonal climate cues. The genetic loci sensitive to predictable environmental signals underlie local adaptation. We dissected natural variation in FT across a new global diversity set of 473 unique accessions, with >12,000 plants across two seasonal plantings in each of two simulated local climates, Spain and Sweden. Genome-wide association mapping was carried out with 213,497 SNPs. A total of 12 FT candidate quantitative trait loci (QTL) were fine-mapped in two independent studies, including 4 located within ±10 kb of previously cloned FT alleles and 8 novel loci. All QTL show sensitivity to planting season and/or simulated location in a multi-QTL mixed model. Alleles at four QTL were significantly correlated with latitude of origin, implying past selection for faster flowering in southern locations. Finally, maximum seed yield was observed at an optimal FT unique to each season and location, with four FT QTL directly controlling yield. Our results suggest that these major, environmentally sensitive FT QTL play an important role in spatial and temporal adaptation.

A Robust Electronic Switch Made of Immobilized Duplex/quadruplex DNA

Angewandte Chemie (International Ed. in English). Dec, 2010  |  Pubmed ID: 21104965

Analysis of the Contribution of Acid Phosphatase to P Efficiency in Brassica Napus Under Low Phosphorus Conditions

Science China. Life Sciences. Jun, 2010  |  Pubmed ID: 20602274

To understand whether genotypic variation in acid phosphatase (APase) activity in rapeseed (Brassica napus L.) induced by phosphorus (P) deficiency has impact on P efficiency, soil APase activity in the rhizosphere for rapeseed P-efficient genotype 102 and P-inefficient genotype 105 was measured against organic and inorganic P sources in the pot experiment, and the activities of root-secreted APase and leaf intracellular APase were investigated in different P-starvation periods in the nutrient solution. Higher activity of root-secreted APase in B. napus was induced under low P conditions. However, P nutrition and P uptake efficiency of the plants supplied with organic P were not directly related to the activity of root-secreted APase due to several confounding factors affecting APase availability. The higher activity of leaf APase improved P remobilization in plants and played important roles in enhancing P use efficiency, shown by the significant correlation between leaf APase activity and P use efficiency in a rapeseed recombinant inbred population of 135 lines.

Microwaves Create Larger Ablations Than Radiofrequency when Controlled for Power in Ex Vivo Tissue

Medical Physics. Jun, 2010  |  Pubmed ID: 20632609

To compare ablation zones created with equal amounts of 2.45 GHz microwave and 480 kHz radiofrequency (RF) energy in ex vivo liver and lung.

Size-controlled Synthesis of Pd Nanocrystals Using a Specific Multifunctional Peptide

Nanoscale. Jun, 2010  |  Pubmed ID: 20648291

Here we report a peptide-mediated synthesis of Pd NCs in aqueous solution with controllable size in the sub-10 nanometre regime. The specific multifunctional peptide Q7 selected using the phage display technique can bind to the Pd NC surface and act as a stabilizer to mediate Pd crystal nucleation and growth. At the nucleation stage, Q7 bound to and helped stabilize the different-sized small Pd NC nuclei achieved using different concentrations of the external reducing agent, NaBH4. At the growth stage, Q7 played the dual role of binding to and reducing the precursor onto the existing nuclei, which led to the further controllable growth of the Pd NCs. By using the variable sizes of nuclei as seeds, and by introducing different amounts of precursors Pd NCs with tunable sizes from 2.6 to 6.6 nm were achieved with good size distribution.

Age-related Changes in Semen Quality Characteristics and Expectations of Reproductive Longevity in Duroc Boars

Animal Science Journal = Nihon Chikusan Gakkaihō. Aug, 2010  |  Pubmed ID: 20662811

Quadratic fitting was used to regress semen characteristics of 1441 samples consisting of 12-month collection from 58 Duroc boars against animal age varied from 10 to 80 months. Data was divided into two groups of cool (14.0-22.7 degrees C, RH 81.5%) and hot season (22.9-29.9 degrees C, RH 86.6%), to test effects of age, season and their interactions. Results revealed that young boars of around 1 year old could endure the hot season. The endurance gradually diminished as animals grew. In the hot season animals exhibited peak performance at age around 33 month and it remained for 1 month, while cool-season kept boars could last for 48 months from 16 months old onward. The reproductive longevity should be 51 month in a subtropical environment and it may extend to 70 month if heat stress can be avoided. The estimated total sperm contribution of a Duroc boar would be 1.8 times more when kept below 22 degrees C than in a natural subtropical environment. It is concluded that to maintain Duroc boars as semen donor to at least 4 years of age is feasible in a subtropical environment and boar longevity could reach 6 years old if well kept in a temperate region.

The Selective Estrogen Receptor Modulator Raloxifene Inhibits Cardiac Delayed Rectifier Potassium Currents and Voltage-gated Sodium Current Without QTc Interval Prolongation

Pharmacological Research : the Official Journal of the Italian Pharmacological Society. Nov, 2010  |  Pubmed ID: 20674746

Raloxifene is widely used in the treatment of postmenopausal osteoporosis and also has been shown to be cardioprotective. The effect of raloxifene on cardiac ion channels is not fully understood. The present study investigated whether raloxifene could affect the cloned hERG channel (I(hERG)) and recombinant human cardiac KCNQ1/KCNE1 channel (I(Ks)) stably expressed in HEK 293 cells using a patch-clamp technique. Raloxifene blocked I(hERG) with an IC(50) of 1.1 μM and decreased I(Ks) (IC(50): 4.8 μM) without affecting activation kinetics. In addition, raloxifene significantly decreased I(Na) (IC(50): 2.8 μM) in guinea pig ventricular myocytes. However, this drug (1 μM) did not increase QRS and QTc interval in isolated guinea pig hearts. These results demonstrate that raloxifene, despite its inhibitory action on delayed rectifier potassium currents, does not prolong ECG QTc interval, suggesting that raloxifene is likely a safe selective estrogen receptor modulator with less cardiac toxicity.

Activation of TRPV1 by Dietary Capsaicin Improves Endothelium-dependent Vasorelaxation and Prevents Hypertension

Cell Metabolism. Aug, 2010  |  Pubmed ID: 20674858

Some plant-based diets lower the cardiometabolic risks and prevalence of hypertension. New evidence implies a role for the transient receptor potential vanilloid 1 (TRPV1) cation channel in the pathogenesis of cardiometabolic diseases. Little is known about impact of chronic TRPV1 activation on the regulation of vascular function and blood pressure. Here we report that chronic TRPV1 activation by dietary capsaicin increases the phosphorylation of protein kinase A (PKA) and eNOS and thus production of nitric oxide (NO) in endothelial cells, which is calcium dependent. TRPV1 activation by capsaicin enhances endothelium-dependent relaxation in wild-type mice, an effect absent in TRPV1-deficient mice. Long-term stimulation of TRPV1 can activate PKA, which contributes to increased eNOS phosphorylation, improves vasorelaxation, and lowers blood pressure in genetically hypertensive rats. We conclude that TRPV1 activation by dietary capsaicin improves endothelial function. TRPV1-mediated increase in NO production may represent a promising target for therapeutic intervention of hypertension.

Very Large Magnetoresistance in Graphene Nanoribbons

Nature Nanotechnology. Sep, 2010  |  Pubmed ID: 20693988

Graphene has unique electronic properties, and graphene nanoribbons are of particular interest because they exhibit a conduction bandgap that arises due to size confinement and edge effects. Theoretical studies have suggested that graphene nanoribbons could have interesting magneto-electronic properties, with a very large predicted magnetoresistance. Here, we report the experimental observation of a significant enhancement in the conductance of a graphene nanoribbon field-effect transistor by a perpendicular magnetic field. A negative magnetoresistance of nearly 100% was observed at low temperatures, with over 50% magnetoresistance remaining at room temperature. This magnetoresistance can be tuned by varying the gate or source-drain bias. We also find that the charge transport in the nanoribbons is not significantly modified by an in-plane magnetic field. The large observed values of magnetoresistance may be attributed to the reduction of quantum confinement through the formation of cyclotron orbits and the delocalization effect under the perpendicular magnetic field.

Depletion of Intracellular Ca2+ Stores Stimulates the Translocation of Vanilloid Transient Receptor Potential 4-c1 Heteromeric Channels to the Plasma Membrane

Arteriosclerosis, Thrombosis, and Vascular Biology. Nov, 2010  |  Pubmed ID: 20705915

To examine the effect of Ca(2+) store depletion on the translocation of vanilloid transient receptor potential (TRPV) 4-C1 heteromeric channels to the plasma membrane.

Contributory Role of Endothelium and Voltage-gated Potassium Channels in Apocynin-induced Vasorelaxations

Journal of Hypertension. Oct, 2010  |  Pubmed ID: 20706137

Although apocynin, the nicotinamide adenine dinucleotide phosphate oxidase inhibitor improves vascular function in hypertension, its specificity has been questioned. The present study examined whether apocynin-induced vasorelaxations involve endothelium and/or K channels in vascular cells.

Adiponectin Prevents Diabetic Premature Senescence of Endothelial Progenitor Cells and Promotes Endothelial Repair by Suppressing the P38 MAP Kinase/p16INK4A Signaling Pathway

Diabetes. Nov, 2010  |  Pubmed ID: 20802255

A reduced number of circulating endothelial progenitor cells (EPCs) are casually associated with the cardiovascular complication of diabetes. Adiponectin exerts multiple protective effects against cardiovascular disease, independent of its insulin-sensitizing activity. The objective of this study was to investigate whether adiponectin plays a role in modulating the bioavailability of circulating EPCs and endothelial repair.

In Vivo Fluorescence Imaging of Tumors Using Molecular Aptamers Generated by Cell-SELEX

Chemistry, an Asian Journal. Oct, 2010  |  Pubmed ID: 20806314

Poor sensitivity and low specificity of current molecular imaging probes limit their application in clinical settings. To address these challenges, we used a process known as cell-SELEX to develop unique molecular probes termed aptamers with the high binding affinity, sensitivity, and specificity needed for in vivo molecular imaging inside living animals. Importantly, aptamers can be selected by cell-SELEX to recognize target cells, or even surface membrane proteins, without requiring prior molecular signature information. As a result, we are able to present the first report of aptamers molecularly engineered with signaling molecules and optimized for the fluorescence imaging of specific tumor cells inside a mouse. Using a Cy5-labeled aptamer TD05 (Cy5-TD05) as the probe, the in vivo efficacy of aptamer-based molecular imaging in Ramos (B-cell lymphoma) xenograft nude mice was tested. After intravenous injection of Cy5-TD05 into mice bearing grafted tumors, noninvasive, whole-body fluorescence imaging then allowed the spatial and temporal distribution to be directly monitored. Our results demonstrate that the aptamers could effectively recognize tumors with high sensitivity and specificity, thus establishing the efficacy of these fluorescent aptamers for diagnostic applications and in vivo studies requiring real-time molecular imaging.

High-speed Graphene Transistors with a Self-aligned Nanowire Gate

Nature. Sep, 2010  |  Pubmed ID: 20811365

Graphene has attracted considerable interest as a potential new electronic material. With its high carrier mobility, graphene is of particular interest for ultrahigh-speed radio-frequency electronics. However, conventional device fabrication processes cannot readily be applied to produce high-speed graphene transistors because they often introduce significant defects into the monolayer of carbon lattices and severely degrade the device performance. Here we report an approach to the fabrication of high-speed graphene transistors with a self-aligned nanowire gate to prevent such degradation. A Co(2)Si-Al(2)O(3) core-shell nanowire is used as the gate, with the source and drain electrodes defined through a self-alignment process and the channel length defined by the nanowire diameter. The physical assembly of the nanowire gate preserves the high carrier mobility in graphene, and the self-alignment process ensures that the edges of the source, drain and gate electrodes are automatically and precisely positioned so that no overlapping or significant gaps exist between these electrodes, thus minimizing access resistance. It therefore allows for transistor performance not previously possible. Graphene transistors with a channel length as low as 140 nm have been fabricated with the highest scaled on-current (3.32 mA μm(-1)) and transconductance (1.27 mS μm(-1)) reported so far. Significantly, on-chip microwave measurements demonstrate that the self-aligned devices have a high intrinsic cut-off (transit) frequency of f(T) = 100-300 GHz, with the extrinsic f(T) (in the range of a few gigahertz) largely limited by parasitic pad capacitance. The reported intrinsic f(T) of the graphene transistors is comparable to that of the very best high-electron-mobility transistors with similar gate lengths.

[Establishment of a Bladder Cancer Cell Line with Toll-like Receptor 2 Gene Knockdown and Identification of Its Biological Characteristics]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Aug, 2010  |  Pubmed ID: 20813668

To establish a murine bladder cancer cell line with stable silencing of toll-like receptor 2 (TLR2) expression.

Sub-100 Nm Channel Length Graphene Transistors

Nano Letters. Oct, 2010  |  Pubmed ID: 20815334

Here we report high-performance sub-100 nm channel length graphene transistors fabricated using a self-aligned approach. The graphene transistors are fabricated using a highly doped GaN nanowire as the local gate with the source and drain electrodes defined through a self-aligned process and the channel length defined by the nanowire size. This fabrication approach allows the preservation of the high carrier mobility in graphene and ensures nearly perfect alignment between source, drain, and gate electrodes. It therefore affords transistor performance not previously possible. Graphene transistors with 45-100 nm channel lengths have been fabricated with the scaled transconductance exceeding 2 mS/μm, comparable to the best performed high electron mobility transistors with similar channel lengths. Analysis of and the device characteristics gives a transit time of 120-220 fs and the projected intrinsic cutoff frequency (f(T)) reaching 700-1400 GHz. This study demonstrates the exciting potential of graphene based electronics in terahertz electronics.

Synthesis, DNA Binding and Cleavage Activity of Macrocyclic Polyamines Bearing Mono- or Bis-acridine Moieties

European Journal of Medicinal Chemistry. Nov, 2010  |  Pubmed ID: 20850912

Two acridine-pendant cyclen (1,4,7,10-tetraazacyclododecane) derivatives 1 and 2 were synthesized, and their DNA interactions have been systematically investigated by UV absorption, fluorescence titration, viscosity measurement, DNA melting and gel electrophoresis experiments. The results showed that acridine-cyclen derivatives could bind to DNA in intercalative mode, and bis-acridine 2 has higher DNA binding ability than that of mono-acridine 1. Moreover, both compounds exhibited preferential interactions with G-rich DNA sequences. Their copper(II) complexes could cleave DNA without the existence of other additives under physiological conditions through an oxidative pathway.

Growth of Nickel Silicides in Si and Si/SiOx Core/shell Nanowires

Nano Letters. Nov, 2010  |  Pubmed ID: 20942385

We exploited the oxide shell structure to explore the structure confinement effect on the nickel silicide growth in one-dimensional nanowire template. The oxide confinement structure is similar to the contact structure (via hole) in the thin film system or nanodevices passivated by oxide or nitride film. Silicon nanowires in direct contact with nickel pads transform into two phases of nickel silicides, Ni31Si12 and NiSi2, after one-step annealing at 550 °C. In a bare Si nanowire during the annealing process, NiSi2 grows initially through the nanowire, followed by the transformation of NiSi2 into the nickel-rich phase, Ni31Si12 starting from near the nickel pad. Ni31Si12 is also observed under the nickel pads. Although the same phase transformations of Si to nickel silicides are observed in nanowires with oxide confinement structure, the growth rate of nickel silicides, Ni31Si12 and NiSi2, is retarded dramatically. With increasing oxide thickness from 5 to 50 nm, the retarding effect of the Ni31Si12 growth and the annihilation of Ni2Si into the oxide confined-Si is clearly observed. Ni31Si12 and Ni2Si phases are limited to grow into the Si/SiOx core-shell nanowire as the shell thickness reaches 50 nm. It is experimental evidence that phase transformation is influenced by the stressed structure at nanoscale.

Patterning and Templating for Nanoelectronics

Advanced Materials (Deerfield Beach, Fla.). Feb, 2010  |  Pubmed ID: 20217787

The semiconductor industry will soon be launching 32 nm complementary metal oxide semiconductor (CMOS) technology node using 193 nm lithography patterning technology to fabricate microprocessors with more than 2 billion transistors. To ensure the survival of Moore's law, alternative patterning techniques that offer advantages beyond conventional top-down patterning are aggressively being explored. It is evident that most alternative patterning techniques may not offer compelling advantages to succeed conventional top-down lithography for silicon integrated circuits, but alternative approaches may well indeed offer functional advantages in realising next-generation information processing nanoarchitectures such as those based on cellular, bioinsipired, magnetic dot logic, and crossbar schemes. This paper highlights and evaluates some patterning methods from the Center on Functional Engineered Nano Architectonics in Los Angeles and discusses key benchmarking criteria with respect to CMOS scaling.

Genistein Potentiates Activity of the Cation Channel TRPC5 Independently of Tyrosine Kinases

British Journal of Pharmacology. Apr, 2010  |  Pubmed ID: 20233211

TRPC5 is a Ca(2+)-permeable channel with multiple modes of activation. We have explored the effects of genistein, a plant-derived isoflavone, on TRPC5 activity, and the mechanism(s) involved.

Plasmonic Modulation of the Upconversion Fluorescence in NaYF(4) :Yb/Tm Hexaplate Nanocrystals Using Gold Nanoparticles or Nanoshells

Angewandte Chemie (International Ed. in English). Apr, 2010  |  Pubmed ID: 20235253

Automatic upgrade: Attachment of gold nanoparticles (NPs) onto upconversion nanocrystals (NCs) results in plasmonic interactions that lead to a significant enhancement of upconversion emission of more than 2.5. Conversely, formation of a gold shell greatly suppresses the NC emission because of considerable scattering of excitation irradiation (see picture; a=NC before seed attachment; b, c=NC with attached Au NPs; c=NC with Au shell; scale bar=50 nm).

Assessment of Biomarkers for Clinical Diagnosis of Papillary Thyroid Carcinoma with Distant Metastasis

The International Journal of Biological Markers. Jan-Mar, 2010  |  Pubmed ID: 20306451

Early diagnosis and treatment of thyroid cancers are critical for better prognosis and better survival rates. The purpose of this study was to identify potential diagnostic markers for papillary thyroid carcinomas with distant metastasis. Fifty-eight papillary thyroid tumor specimens (27 papillary thyroid carcinomas with distant metastasis and 31 without metastasis) were examined, and protein expression of pituitary tumor-transforming gene (PTTG), E-cadherin, p27kip1, vascular endothelial growth factor (VEGF)-C, metalloproteinase (MMP) 2, MMP9, chemokine receptor CXCR4, and basic fibroblast growth factor (bFGF) in these tumors was assessed by immunohistochemistry. The clinicopathological variables with diagnostic significance were determined by multivariate analysis, and their diagnostic values were evaluated by ROC curve analysis. PTTG, VEGF-C, MMP2, MMP9, CXCR4, and bFGF were overexpressed in metastatic papillary thyroid carcinomas, whereas p27kip1 expression was elevated only in carcinomas lacking metastasis. Multiple-factor binary ordinal logistic regression analysis revealed that PTTG, VEGF-C, MMP2, and bFGF were independently related to biological metastatic behavior in thyroid tumors, suggesting their potential use as biomarkers. ROC curve analysis showed that among these four proteins, VEGF-C and bFGF were the best diagnostic biomarkers. A VEGF-C and bFGF cluster was the most useful factor for the differential diagnosis between metastatic and non-metastatic papillary thyroid cancers. Thus, the combined use of VEGF-C and bFGF as biomarkers may improve the diagnostic accuracy of papillary thyroid carcinoma and may be useful in multimodal screening programs for the clinical diagnosis of papillary thyroid carcinoma and early detection of papillary thyroid carcinoma with distant metastasis.

High-kappa Oxide Nanoribbons As Gate Dielectrics for High Mobility Top-gated Graphene Transistors

Proceedings of the National Academy of Sciences of the United States of America. Apr, 2010  |  Pubmed ID: 20308584

Deposition of high-kappa dielectrics onto graphene is of significant challenge due to the difficulties of nucleating high quality oxide on pristine graphene without introducing defects into the monolayer of carbon lattice. Previous efforts to deposit high-kappa dielectrics on graphene often resulted in significant degradation in carrier mobility. Here we report an entirely new strategy to integrate high quality high-kappa dielectrics with graphene by first synthesizing freestanding high-kappa oxide nanoribbons at high temperature and then transferring them onto graphene at room temperature. We show that single crystalline Al(2)O(3) nanoribbons can be synthesized with excellent dielectric properties. Using such nanoribbons as the gate dielectrics, we have demonstrated top-gated graphene transistors with the highest carrier mobility (up to 23,600 cm(2)/V x s) reported to date, and a more than 10-fold increase in transconductance compared to the back-gated devices. This method opens a new avenue to integrate high-kappa dielectrics on graphene with the preservation of the pristine nature of graphene and high carrier mobility, representing an important step forward to high-performance graphene electronics.

Vasoconstrictor Prostanoids

Pflügers Archiv : European Journal of Physiology. May, 2010  |  Pubmed ID: 20333529

In cardiovascular diseases and during aging, endothelial dysfunction is due in part to the release of endothelium-derived contracting factors that counteract the vasodilator effect of the nitric oxide. Endothelium-dependent contractions involve the activation of endothelial cyclooxygenases and the release of various prostanoids, which activate thromboxane prostanoid (TP) receptors of the underlying vascular smooth muscle. The stimulation of TP receptors elicits not only the contraction and the proliferation of vascular smooth muscle cells but also diverse physiological/pathophysiological reactions, including platelet aggregation and activation of endothelial inflammatory responses. TP receptor antagonists curtail endothelial dysfunction in diseases such as hypertension and diabetes, are potent antithrombotic agents, and prevent vascular inflammation.

[Expression of MicroRNA-21 in Ovarian Epithelial Carcinoma and Its Clinical Significance]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Mar, 2010  |  Pubmed ID: 20335152

To investigate the expression of microRNA-21(miR-21) in ovarian epithelial carcinoma and its association with the clinicopathological features.

Genome-wide Association Study of 107 Phenotypes in Arabidopsis Thaliana Inbred Lines

Nature. Jun, 2010  |  Pubmed ID: 20336072

Although pioneered by human geneticists as a potential solution to the challenging problem of finding the genetic basis of common human diseases, genome-wide association (GWA) studies have, owing to advances in genotyping and sequencing technology, become an obvious general approach for studying the genetics of natural variation and traits of agricultural importance. They are particularly useful when inbred lines are available, because once these lines have been genotyped they can be phenotyped multiple times, making it possible (as well as extremely cost effective) to study many different traits in many different environments, while replicating the phenotypic measurements to reduce environmental noise. Here we demonstrate the power of this approach by carrying out a GWA study of 107 phenotypes in Arabidopsis thaliana, a widely distributed, predominantly self-fertilizing model plant known to harbour considerable genetic variation for many adaptively important traits. Our results are dramatically different from those of human GWA studies, in that we identify many common alleles of major effect, but they are also, in many cases, harder to interpret because confounding by complex genetics and population structure make it difficult to distinguish true associations from false. However, a-priori candidates are significantly over-represented among these associations as well, making many of them excellent candidates for follow-up experiments. Our study demonstrates the feasibility of GWA studies in A. thaliana and suggests that the approach will be appropriate for many other organisms.

Photocatalytic Removal of NO and HCHO over Nanocrystalline Zn2SnO4 Microcubes for Indoor Air Purification

Journal of Hazardous Materials. Jul, 2010  |  Pubmed ID: 20346586

Nanocrystalline Zn(2)SnO(4) microcubes were hydrothermally synthesized and systematically characterized by XRD, SEM, TEM, XPS, N(2) adsorption-desorption, and UV-vis DRS analysis. The resulting Zn(2)SnO(4) microcubes with the edge size ranging from 0.8 to 1.2 microm were composed of numerous nanoparticles with size of 10-20 nm, and their optical band gap energy was estimated to be 3.25 eV from the UV-vis diffuse reflectance spectra. On degradation of nitrogen monoxide (NO) and formaldehyde (HCHO) at typical concentrations for indoor air quality, these nanocrystalline Zn(2)SnO(4) microcubes exhibited superior photocatalytic activity to the hydrothermally synthesized ZnO, SnO(2), and Degussa TiO(2) P25, as well as C doped TiO(2) under UV-vis light irradiation. This enhanced photocatalytic activity of the nanocrystalline Zn(2)SnO(4) microcubes was attributed to their bigger surface areas, smaller particle size, special porous structures, and special electronic configuration. The nanocrystalline Zn(2)SnO(4) microcubes were chemically stable as there was no obvious deactivation during the multiple photocatalytic reactions. This work presents a promising approach for scaling-up industrial production of Zn(2)SnO(4) nanostructures and suggests that the synthesized nanocrystalline Zn(2)SnO(4) microcubes are promising photocatalysts for indoor air purification.

Preparation of Cross-linked Aggregates of Aminoacylase from Aspergillus Melleus by Using Bovine Serum Albumin As an Inert Additive

Bioresource Technology. Aug, 2010  |  Pubmed ID: 20363123

The effects of bovine serum albumin (BSA) addition on the cross-linked enzyme aggregates (CLEA) of aminoacylase from Aspergillus melleus (EC 3.5.1.14) were conducted at varying glutaraldehyde to enzyme ratio. After optimization, CLEA of aminoacylase prepared with 10 mg BSA per 100 mg enzyme retained 82% activity recovery (named CLEA-E-BSA) whereas CLEA prepared without BSA retained only 24% activity recovery (named CLEA-E) due to the low content of amine residues of aminoacylase. Compared with free aminoacylase, the catalytic performance of CLEA-E-BSA (k(cat)/K(m)) decreased from 0.357 to 0.270, while the thermal stability of CLEA-E-BSA has improved considerably, maintaining 52% residual activity after 24h of incubation at 47 degrees C whereas the free enzyme was almost inactivated. Additionally, the inactive curve of CLEA-E-BSA fitted a two-exponential deactivation model. The reusability of CLEA-E-BSA with respect to N-acetyl-DL-methionine hydrolysis was evaluated. CLEA-E-BSA showed 82.4% residual activity even after 10 cycles of repeated use.

Rational Design and Synthesis of Freestanding Photoelectric Nanodevices As Highly Efficient Photocatalysts

Nano Letters. May, 2010  |  Pubmed ID: 20373781

Photocatalysts are of significant interest in solar energy harvesting and conversion into chemical energy. However, the photocatalysts available to date are limited by either poor efficiency in the visible light range or insufficient photoelectrochemical stability. Here we report the rational design of a new generation of freestanding photoelectric nanodevices as highly efficient and stable photocatalysts by integrating a nanoscale photodiode with two redox catalysts in a single nanowire heterostructure. We show that a platinum-silicon-silver nanowire heterostructure can be synthesized to integrate a nanoscale metal-semiconductor Schottky diode encased in a protective insulating shell with two exposed metal catalysts. We further demonstrated that the Schottky diodes exhibited a pronounced photovoltaic effect with nearly unity internal quantum efficiency and that the integrated nanowire heterostructures could be used as highly efficient photocatalysts for a wide range of thermodynamically downhill and uphill reactions including the photocatalytic degradation of organic dyes and the reduction of metal ions and carbon dioxide using visible light. Our studies for the first time demonstrated the integration of multiple distinct functional components into a single nanostructure to form a standalone active nanosystem and for the first time successfully realized a photoelectric nanodevice that is both highly efficient and highly stable throughout the entire solar spectrum. It thus opens a rational avenue to the design and synthesis of a new generation of photoelectric nanosystems with unprecedented efficiency and stability and will have a broad impact in areas including environmental remediation, artificial photosynthesis and solar fuel production.

Top-gated Graphene Nanoribbon Transistors with Ultrathin High-k Dielectrics

Nano Letters. May, 2010  |  Pubmed ID: 20380441

The integration ultrathin high dielectric constant (high-k) materials with graphene nanoribbons (GNRs) for top-gated transistors can push their performance limit for nanoscale electronics. Here we report the assembly of Si/HfO(2) core/shell nanowires on top of individual GNRs as the top-gates for GNR field-effect transistors with ultrathin high-k dielectrics. The Si/HfO(2) core/shell nanowires are synthesized by atomic layer deposition of the HfO(2) shell on highly doped silicon nanowires with a precise control of the dielectric thickness down to 1-2 nm. Using the core/shell nanowires as the top-gates, high-performance GNR transistors have been achieved with transconductance reaching 3.2 mS microm(-1), the highest value for GNR transistors reported to date. This method, for the first time, demonstrates the effective integration of ultrathin high-k dielectrics with graphene with precisely controlled thickness and quality, representing an important step toward high-performance graphene electronics.

Frequent Cholesterol Intake Up-regulates Intestinal NPC1L1, ACAT2, and MTP

Journal of Agricultural and Food Chemistry. May, 2010  |  Pubmed ID: 20405839

Dietary cholesterol elevates plasma total cholesterol (TC) level. However, no study to date has examined how cholesterol intake frequency interacts with the gene of sterol transporters, receptors, and enzymes involved in cholesterol metabolism. Thirty-three hamsters were divided into three groups with the control hamsters being given daily 9 mg of cholesterol in the diet (CD), whereas the second group being gavage-administered 3 mg of cholesterol three times per day (C-3) and the third group being gavage-administered 9 mg of cholesterol one time per day (C-1). The experiment lasted for 6 weeks. The hamsters were killed under carbon dioxide suffocation. Data demonstrated that plasma TC, non-high-density lipoprotein cholesterol, and triacylglycerols were elevated with the increasing cholesterol intake frequency. Western blotting analyses revealed that the intake frequency had no effect on protein mass of hepatic sterol regulatory element binding protein-2, liver X receptor-alpha, 3-hydroxy-3-methylglutaryl-CoA reductase, LDL receptor, and cholesterol-7alpha-hydroxylase. However, the frequent cholesterol intake down-regulated the mRNA level of hepatic LDL receptor. In contrast, the frequent cholesterol intake up-regulated the mRNA levels of intestinal Niemann-Pick C1-like 1 (NPC1L1), acyl coenzyme A:cholesterol acyltransferase 2 (ACAT2), and microsomal triacylglycerol transport protein (MTP). It was concluded that the cholesterol intake frequency-induced elevation in plasma TC was associated with greater cholesterol absorption, possibly mediated by up-regulation of NPC1L1, ACAT2, and MTP.

[Cloning of ID4 Gene Expression Regulation Promoter and Subcloning of Recombinant ID4 Promoter Luciferase Reporter]

Zhongguo Shi Yan Xue Ye Xue Za Zhi / Zhongguo Bing Li Sheng Li Xue Hui = Journal of Experimental Hematology / Chinese Association of Pathophysiology. Apr, 2010  |  Pubmed ID: 20416180

The present study was aimed to clone ID4 gene promoter and upstream regulatory region, and to construct a series of recombinant promoter-luciferase reporter for exploring the mechanism of ID4 gene expression regulation. Methods and results: the upstream 5' flanking sequence of 2242 bp from transcriptional start site (TSS) and downstream 5' non-coding region of 212 bp on ID4 gene were searched out and downloaded from human genome databank of NCBI using whole length of ID4 gene cDNA as a probe; On-line promoter analysis softwares, including TESS and Genomax, were employed to analyze the characteristics of ID4 gene promoter and upstream regulatory elements. Then, based on the analytic results, PCR primers were designed and synthesized. Segmental amplification method was adopted to obtain two fragments of 1829 bp and 784 bp. The two fragments were inserted into the plasmid pGEM-T, transformed into TOP10 competent E. coli., and positive recombinants were screened respectively. Subsequently, restriction enzymes KpnI/NheI and KpnI/EcoRI were used to digest the above-mentioned two plasmids pGEM-T and pGL3, and ligation was completed by T4 DNA ligase. After transformation to TOP10 competent E. coli. and screening of positive colonies, the basic recombinant ID4 gene promoter-pGL3 was successfully constructed. KpnI/NheI double digestion and sequencing showed that the target fragment was 2 459 bp and consistent with the corresponding sequence of GenBank; Using the 2459 bp fragment as a template, 5 pairs of primers with identical 3' terminus and different 5' terminus were designed and synthesized for half-nest PCR amplification. 5 fragments with an interval of approximate 400 bp each other, i.e. 2112 bp, 1703 bp, 1290 bp, 784 bp and 496 bp, were produced and inserted into pGEM-T after recovery and purification for transformation to TOP10 competent E. coli. and screening of positive colonies. After that, KpnI/NheI was used to digest the above-mentioned five pGEM-T recombinant plasmids and pGL3 basic vector, and the ligation was completed by T4 DNA ligase. After transformation to TOP10 competent E. coli. and screening for positive colonies, 5 subcloned recombinants of ID4 gene promoter and pGL3 Basic vector cells were constructed. In conclusion, 2.5 kb ID4 gene promoter with upstream expression regulatory sequence was successfully cloned and a series of ID4 promoter subclone-pGL3-Basic recombinant were constructed for further researches on activity, expression regulation and function of ID4 promoter.

Endothelial Dysfunction: the Common Consequence in Diabetes and Hypertension

Journal of Cardiovascular Pharmacology. Apr, 2010  |  Pubmed ID: 20422734

Endothelial dysfunction plays a key role in the initiation of cellular events evolving into the development of vascular complications in diabetes and hypertension. Diminished production and function of endothelium-derived nitric oxide and other vasoprotective factors and/or the exaggerated production of proinflammatory and vasoconstrictors such as angiotensin II, endothelin-1, reactive oxygen species, and cyclooxygenase-derived metabolites of arachidonic acid eventually lead to endothelial dysfunction, resulting in elevated vascular tone which contributes to hypertension, vascular, and cardiac remodeling, culminating in microvascular, macrovascular, and renal damages. Specific therapies targeting reactive oxygen species using antioxidants and inhibitors of the rennin-angiotensin system or increasing endothelial nitric oxide synthase activity might assist to reverse endothelial dysfunction and thus reduce the related cardiovascular morbidity and mortality in diabetes and hypertension.

Baicalein and Wogonin Inhibit Collagen Deposition in SHR and WKY Cardiac Fibroblast Cultures

BMB Reports. Apr, 2010  |  Pubmed ID: 20423617

In order to demonstrate the potential therapeutic effect of two flavonoids, Baicalein and Wogonin, on suppression of pathological myocardial fibrosis in hypertension, we investigated their in vitro effects on collagen expression in primary cultured cardiac fibroblasts isolated from neonatal normotensive (WKY) and hypertensive (SHR) rats. Our results showed that over-expression of collagen mRNA and protein induced in cardiac fibroblasts by angiotensin (AngII) could be attenuated significantly by both flavonoids at an optimal dosage (30 microM; P < 0.01). Results of immunoblots showed that expression of 12-LO level, p-ERK/ ERK ratio and MMP-9 in AngII|-stimulated SHR cardiac fibroblasts were significantly down-regulated by both flavonoids. Our results show that both Baicalein and Wogonin can suppress collagen deposition in AngII-stimulated SHR and WKY cardiac fibroblasts.

Adventitia As a Critical Player in the Functional Integrity of Arteries. - Additional Support for Novel Clinical Procedures -

Circulation Journal : Official Journal of the Japanese Circulation Society. May, 2010  |  Pubmed ID: 20424333

4-aminopyridine-sensitive K+ Channels Contributes to NaHS-induced Membrane Hyperpolarization and Relaxation in the Rat Coronary Artery

Vascular Pharmacology. Sep-Oct, 2010  |  Pubmed ID: 20430111

The present study aimed at examining the role of potassium channels and endothelium in relaxations induced by sodium hydrogen sulphide (NaHS), which is the donor of gaseous hydrogen sulphide (H(2)S) and the effect of NaHS on endothelium-dependent relaxations in rat coronary arteries. Rat coronary arteries were suspended in a myograph for force measurement and changes of the membrane potential in arteries were determined by membrane potential-sensitive fluorescence dye. NaHS relaxed coronary arteries pre-contracted by U46619 and the relaxation was significantly less in high KCl-contracted rings. NaHS-induced relaxations were reduced by 4-aminopyridine (4-AP) but unaffected by glibenclamide, iberiotoxin, N(G)-nitro-L-arginine methyl ester, ODQ, indomethacin or by endothelium removal. The inhibitory effect of 4-AP was absent in NaHS-induced relaxations in high KCl-contracted rings. Addition of NaHS caused membrane hyperpolarization and this effect was inhibited by 4-AP but not by glibenclamide. NaHS causes endothelium-independent relaxations in rat coronary arteries partially through activation of 4-AP-sensitive potassium channel and ensuring hyperpolarization. Other potassium channels, Na(+)-K(+) pump or endothelium-derived relaxing factors play little role.

Study of Na+/H+ Exchange-mediated PHi Regulations in Neuronal Soma and Neurites in Compartmentalized Microfluidic Devices

Integrative Biology : Quantitative Biosciences from Nano to Macro. Jan, 2010  |  Pubmed ID: 20473413

Regulation of intracellular pH (pH(i)) in neurons is crucial to maintain their physiological function. In the current study, newly-developed polydimethylsiloxane (PDMS) microfluidic devices were used to independently investigate pH(i) regulation in neuronal soma and neurites. Embryonic cortical neurons were cultured in PDMS microfluidic devices with soma growing in one chamber (seeded) and neurites extending through a set of perpendicular microchannels into the opposite parallel chamber (non-seeded). Neurons in the microchambers were characterized by the vital dye calcein-red, polarized mitochondria, and expression of neuronal specific beta-tubulin (type-III), axonal Tau-1 protein, dendritic microtubule associated protein (MAP-2), and Na(+)/H(+) exchanger isoform 1 (NHE-1). Neurites exhibited higher resting pH(i) than soma (7.16 +/- 0.09 vs. 6.90 +/- 0.15). The neurites had a proton extrusion rate 3.7-fold faster than in soma following NH(4)Cl prepulse-mediated acidification (p < 0.05). The difference in the pH(i) regulation rates between neurites and soma can be accounted for by the larger surface area to volume ratio in the neurites. Interestingly, pharmacological inhibition of NHE-1 activity blocked the pH(i) regulation in soma and in neurites by approximately 70% (p < 0.05). Taken together, our study demonstrated that the microfluidic devices provide a useful tool to study neuronal pH(i) regulation in soma and their neurites. We conclude that NHE-1 plays an important role in regulation of pH(i) in both compartments.

Genome-wide Survey of Arabidopsis Natural Variation in Downy Mildew Resistance Using Combined Association and Linkage Mapping

Proceedings of the National Academy of Sciences of the United States of America. Jun, 2010  |  Pubmed ID: 20479233

The model plant Arabidopsis thaliana exhibits extensive natural variation in resistance to parasites. Immunity is often conferred by resistance (R) genes that permit recognition of specific races of a disease. The number of such R genes and their distribution are poorly understood. In this study, we investigated the basis for resistance to the downy mildew agent Hyaloperonospora arabidopsidis ex parasitica (Hpa) in a global sample of A. thaliana. We implemented a combined genome-wide mapping of resistance using populations of recombinant inbred lines and a collection of wild A. thaliana accessions. We tested the interaction between 96 host genotypes collected worldwide and five strains of Hpa. Then, a fraction of the species-wide resistance was genetically dissected using six recently constructed populations of recombinant inbred lines. We found that resistance is usually governed by single dominant R genes that are concentrated in four genomic regions only. We show that association genetics of resistance to diseases such as downy mildew enables increased mapping resolution from quantitative trait loci interval to candidate gene level. Association patterns in quantitative trait loci intervals indicate that the pool of A. thaliana resistance sources against the tested Hpa isolates may be predominantly confined to six RPP (Resistance to Hpa) loci isolated in previous studies. Our results suggest that combining association and linkage mapping could accelerate resistance gene discovery in plants.

Detection of Spin Polarized Carrier in Silicon Nanowire with Single Crystal MnSi As Magnetic Contacts

Nano Letters. Jun, 2010  |  Pubmed ID: 20499889

We report the formation of single crystal MnSi nanowires, MnSi/Si/MnSi nanowire heterostructures, to study the spin transport in silicon nanostructure. Scanning electron microscopy studies show that silicon nanowires can be converted into single crystal MnSi nanowires through controlled solid-state reaction. High-resolution transmission electron microscope studies show that MnSi/Si/MnSi heterostructures have clean, atomically sharp interfaces with an epitaxial relationship of Si[311]//MnSi[120] and Si(345)//MnSi(214). Magnetoresistance (MR) studies show that the single crystal MnSi nanowire exhibits metallic behavior with paramagnetic to ferromagnetic transition temperature of 29.7 K and a negative MR up to 1.8% at low temperature. Furthermore, using single crystal MnSi/p-Si/MnSi nanowire heterostructures, we have studied carrier tunneling via the Schottky barrier and spin polarized carrier transport in the silicon nanodevices.

Anemoside A3-induced Relaxation in Rat Renal Arteries: Role of Endothelium and Ca2+ Channel Inhibition

Planta Medica. Nov, 2010  |  Pubmed ID: 20506075

Anemoside A(3), a lupane-type triterpenoid saponin, exists in the roots of Pulsatilla chinensis, but its pharmacological properties are largely unknown. The present study aimed to investigate the mechanisms underlying anemoside A(3)-induced relaxation in rat renal arteries. Changes of isometric force were determined on arteries with a myograph. Anemoside A(3) caused concentration-dependent relaxation in precontracted aortas, mesenteric, left coronary, and renal arteries. Removal of endothelium or treatment with charybdotoxin plus apamin slightly but significantly attenuated the relaxation in renal arteries. TEA(+) inhibited the relaxation caused by anemoside A(3) in renal arteries with and without endothelium while glibenclamide, BaCl(2), or capsaicin had no effect on it. Anemoside A(3) produced less relaxation in rings contracted by 60 mM KCl compared with rings contracted by receptor-dependent constrictors. It further inhibited contractions induced by Ca(2+) influx through nifedipine-sensitive voltage-gated Ca(2+) channels, nifedipine-insensitive receptor-operated Ca(2+) channels, and by intracellular Ca(2+) release. Pretreatment with nifedipine attenuated anemoside A(3)-induced relaxation. Taken together, the present results indicate that anemoside A(3) produces relaxation in rat renal arteries through multiple mechanisms. The release of CTX/apamin-sensitive endothelium-derived hyperpolarizing factor, stimulation of TEA(+)-sensitive K(+) channel, and inhibition of Ca(2+) influx jointly contribute to the relaxation.

[Peripheral Blood Th17 Cell and Serum IL-17A in Primary Biliary Cirrhosis]

Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. May, 2010  |  Pubmed ID: 20510006

Rosiglitazone Attenuates Endothelin-1-induced Vasoconstriction by Upregulating Endothelial Expression of Endothelin B Receptor

Hypertension. Jul, 2010  |  Pubmed ID: 20516393

Thiazolidinediones improve insulin resistance and endothelial dysfunction. However, the mechanisms underlying the vasoprotective effects of thiazolidinediones remain to be fully elucidated. The present study aimed to examine the molecular mechanism for the anti-vasoconstrictive effects of rosiglitazone in response to endothelin (ET) 1. Mouse aortas were treated with rosiglitazone for 24 hours, and ET-1-induced vasoconstriction was assessed by wire myography. The results showed that rosiglitazone attenuated ET-1-induced contraction in mouse aortas; this effect was abolished by ET-B receptor (ET(B)R) antagonist, NO synthase inhibitor, and by the removal of endothelium. By using Northern blotting, real-time RT-PCR, Western blotting, and immunohistochemical techniques, we found that rosiglitazone upregulated expression of ET(B)R at both mRNA and protein levels in mouse aortas and human vascular endothelial cells. The induction of ET(B)R was prevented by peroxisome proliferator-activated receptor-gamma antagonism. Luciferase reporter assay showed that rosiglitazone enhanced ET(B)R gene promoter activity. Furthermore, chromatin immunoprecipitation assays demonstrated that peroxisome proliferator-activated receptor-gamma can directly bind to ET(B)R gene promoter. Furthermore, in vivo treatment with rosiglitazone also attenuated the ET-1-induced vasoconstrictions and increased the ET(B)R expression in mouse aortas and mesenteric arteries. In conclusion, these results demonstrate that rosiglitazone attenuated ET-1-induced vasoconstriction through the upregulation of endothelial ET(B)R, which is a peroxisome proliferator-activated receptor-gamma direct target.

Natural Allelic Variation Underlying a Major Fitness Trade-off in Arabidopsis Thaliana

Nature. Jun, 2010  |  Pubmed ID: 20520716

Plants can defend themselves against a wide array of enemies, from microbes to large animals, yet there is great variability in the effectiveness of such defences, both within and between species. Some of this variation can be explained by conflicting pressures from pathogens with different modes of attack. A second explanation comes from an evolutionary 'tug of war', in which pathogens adapt to evade detection, until the plant has evolved new recognition capabilities for pathogen invasion. If selection is, however, sufficiently strong, susceptible hosts should remain rare. That this is not the case is best explained by costs incurred from constitutive defences in a pest-free environment. Using a combination of forward genetics and genome-wide association analyses, we demonstrate that allelic diversity at a single locus, ACCELERATED CELL DEATH 6 (ACD6), underpins marked pleiotropic differences in both vegetative growth and resistance to microbial infection and herbivory among natural Arabidopsis thaliana strains. A hyperactive ACD6 allele, compared to the reference allele, strongly enhances resistance to a broad range of pathogens from different phyla, but at the same time slows the production of new leaves and greatly reduces the biomass of mature leaves. This allele segregates at intermediate frequency both throughout the worldwide range of A. thaliana and within local populations, consistent with this allele providing substantial fitness benefits despite its marked impact on growth.

Morphology-controlled Synthesis of Platinum Nanocrystals with Specific Peptides

Advanced Materials (Deerfield Beach, Fla.). May, 2010  |  Pubmed ID: 20526995

High-performance Top-gated Graphene-nanoribbon Transistors Using Zirconium Oxide Nanowires As High-dielectric-constant Gate Dielectrics

Advanced Materials (Deerfield Beach, Fla.). May, 2010  |  Pubmed ID: 20526997

Reporter-based Isolation of Induced Pluripotent Stem Cell- and Embryonic Stem Cell-derived Cardiac Progenitors Reveals Limited Gene Expression Variance

Circulation Research. Aug, 2010  |  Pubmed ID: 20558827

Induced pluripotent stem (iPS) cells can differentiate into multiple cell types, including cardiomyocytes and have tremendous potential for drug discovery and regenerative therapies. However, it is unknown how much variability exists between differentiated lineages from independent iPS cell lines and, specifically, how similar iPS cell-derived cardiomyocytes (iPS-CMs) are to embryonic stem (ES) cell-derived cardiomyocytes (ES-CMs).

Cyclic Nucleotide-gated Channels Contribute to Thromboxane A2-induced Contraction of Rat Small Mesenteric Arteries

PloS One. 2010  |  Pubmed ID: 20559420

Thromboxane A(2) (TxA(2))-induced smooth muscle contraction has been implicated in cardiovascular, renal and respiratory diseases. This contraction can be partly attributed to TxA(2)-induced Ca(2+) influx, which resulted in vascular contraction via Ca(2+)-calmodulin-MLCK pathway. This study aims to identify the channels that mediate TxA(2)-induced Ca(2+) influx in vascular smooth muscle cells.

Systemic Peripheral Artery Relaxation by KCNQ Channel Openers and Hydrogen Sulfide

Journal of Hypertension. Sep, 2010  |  Pubmed ID: 20577128

Perivascular adipose tissue secretes an adipocyte-derived relaxing factor (ADRF) that opens voltage-dependent K (Kv) channels in peripheral arteries. We studied the role of KCNQ-type Kv channels and tested the hypothesis that hydrogen sulfide (H2S) could be an ADRF.

Angiotensin AT1 Receptor Activation Mediates High Glucose-induced Epithelial-mesenchymal Transition in Renal Proximal Tubular Cells

Clinical and Experimental Pharmacology & Physiology. Sep, 2010  |  Pubmed ID: 20590668

1. Renal tubular epithelial cells can undergo epithelial to mesenchymal transition (EMT) under hyperglycaemic conditions, which is associated with renal interstitial fibrosis. Activation of the renin-angiotensin system (RAS) is involved in diabetic nephropathy. The present study investigated the positive role of angiotensin AT1 receptors in high glucose-induced EMT in cultured tubular epithelial cells. 2. A rat kidney proximal tubular epithelial cell line (NRK-52E) was used in the present study. Levels of EMT makers, namely E-cadherin and vimentin, were estimated using fluorescence immunocytochemistry, mRNA levels of angiotensinogen (AGT), angiotensin-converting enzyme (ACE) and AT1 receptors were determined by real-time polymerase chain reaction, protein levels of E-cadherin, vimentin, fibronectin, matrix metallopeptidase (MMP)-9 and phosphorylated extracellular signal-regulated kinase (ERK) 1/2 were analysed by western blotting and the concentrations of angiotensin (Ang) II and transforming growth factor (TGF)-beta1 in the culture medium were determined by enzyme immunoassay and ELISA. 3. High glucose (30 mmol/L) induced EMT and increased the synthesis of fibronectin and MMP-9. Furthermore, high glucose increased AGT, ACE and AT(1) receptor mRNA levels, as well as AngII and TGF-beta1 concentrations in the culture medium and ERK1/2 phosphorylation. Pretreatment of cells for 15 min with the AT1 receptor antagonist losartan (10(-5) mol/L) attenuated high glucose-induced increases in TGF-beta1 and ERK1/2 phosphorylation and reduced EMT, as well as the consequent synthesis of fibronectin and MMP-9. 4. The results of the present study suggest that the activated local RAS mediates high glucose-induced EMT. By activating AT1 receptors and stimulating TGF-beta1 synthesis, the elevated local RAS participates in high glucose-induced EMT and increased extracellular matrix secretion.

Hypocholesterolemic Activity of Grape Seed Proanthocyanidin is Mediated by Enhancement of Bile Acid Excretion and Up-regulation of CYP7A1

The Journal of Nutritional Biochemistry. Nov, 2010  |  Pubmed ID: 20092993

Interest in grape seed proanthocyanidin (GSP) as a cholesterol-lowering nutraceutical is growing. This study was to investigate the effect of GSP on blood cholesterol level and gene expression of cholesterol-regulating enzymes in Golden Syrian hamsters maintained on a 0.1% cholesterol diet. Results affirmed supplementation of 0.5% or 1.0% GSP could decrease plasma total cholesterol and triacylglycerol level. Western blot and real-time polymerase chain reaction analyses demonstrated GSP did not affect sterol regulatory element binding protein-2 and low-density lipoprotein receptor; however, it increased mRNA 3-hydroxy-3-methylglutaryl coenzyme A reductase. GSP had no effect on the protein mass of liver X receptor alpha (LXRα) but it decreased mRNA LXRα. Most importantly, GSP increased not only the protein level of cholesterol-7α-hydroxylase (CYP7A1) but also mRNA CYP7A1. It was concluded that the hypocholesterolemic activity of GSP was most likely mediated by enhancement of bile acid excretion and up-regulation of CYP7A1.

Functional Role of Vanilloid Transient Receptor Potential 4-canonical Transient Receptor Potential 1 Complex in Flow-induced Ca2+ Influx

Arteriosclerosis, Thrombosis, and Vascular Biology. Apr, 2010  |  Pubmed ID: 20093626

The present study is aimed at investigating the interaction of TRPV4 with TRPC1 and the functional role of such an interaction in flow-induced Ca(2+) influx. Hemodynamic blood flow is an important physiological factor that modulates vascular tone. One critical early event in this process is a cytosolic Ca(2+) ([Ca(2+)](i)) rise in endothelial cells in response to flow.

Prostanoid TP Receptor-mediated Impairment of Cyclic AMP-dependent Vasorelaxation is Reversed by Phosphodiesterase Inhibitors

European Journal of Pharmacology. Apr, 2010  |  Pubmed ID: 20096281

Activation of the thromboxane prostanoid (TP) receptor produces potent vasoconstriction, which contributes to the increased vascular tone and blood pressure. The present study was designed to examine the hypothesis that stimulation of prostanoid TP receptors impairs endothelium-independent relaxations to cyclic AMP-elevating agents via increasing the activity of phosphodiesterases (PDEs). Rat carotid arteries without endothelium were isolated and suspended in myograph for the measurement of changes in isometric tension; the tissue content of cyclic AMP was assayed by enzyme immunoassay kit; and prostanoid TP receptor was detected in vascular wall by immunohistochemistry and Western blot. In phenylephrine-contracted rings without endothelium, relaxations induced by isoprenaline (receptor-mediated) and forskolin (receptor-independent) were markedly reduced by the presence of a prostanoid TP receptor agonist, U46619; the attenuated relaxations were prevented by acute treatment with S18886, the selective prostanoid TP receptor antagonist, but not by protein kinase C inhibitors. The reduced relaxations were partially restored by IBMX (non-selective PDE inhibitor), cilostazol (PDE3 inhibitor), rolipram (PDE4 inhibitor) or by Y27632 (Rho kinase inhibitor), but not by T0156 (PDE5 inhibitor). U46619 diminished isoprenaline- or forskolin-stimulated rise in cyclic AMP and this effect was inhibited by cilostazol, rolipram or Y27632. The present results suggest that activation of prostanoid TP receptors impairs cyclic AMP-dependent vasorelaxations partly via PDE- and RhoA/Rho kinase-dependent mechanisms. Inhibitors of PDEs and Rho kinase may be useful in the treatment of cardiovascular complications.

Cyclic Guanosine Monophosphate Dependent Pathway Contributes to Human Mast Cell Inhibitory Actions of the Nitric Oxide Donor, Diethylamine NONOate

European Journal of Pharmacology. Apr, 2010  |  Pubmed ID: 20096283

We have previously demonstrated that exogenous nitric oxide (NO) inhibited anti-IgE-mediated histamine release from human cultured mast cells. In the current study, we further investigated if syntheses of eicosanoids and cytokines were also suppressed by NO donors and evaluated if activation of soluble guanylyl cyclase (sGC) was an underlying mechanism. The effects of the NO donor diethylamine NONOate (DEA/NO) on IgE-dependent syntheses of eicosanoids (prostaglandin D(2) and cysteinyl leukotrienes) and cytokines (tumor necrosis factor-alpha and interleukin-8) from buffy coat derived human cultured mast cells were examined. The effects of sGC related agents on human mast cell activation were studied by measuring histamine release. DEA/NO (10(-7)-10(-4)M) dose-dependently inhibited anti-IgE induced release of histamine, eicosanoids and cytokines. It could also significantly increase intracellular cyclic guanosine monophosphate (cGMP) but reduce anti-IgE induced activation of ERK1/2, JNK1/2 and NF-kappaB. The inhibition of anti-IgE induced histamine release by DEA/NO was reversed by the sGC inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10(-7)M) and the cGMP-dependent protein kinase (PKG) inhibitor, Rp-8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphorothioate (Rp-8-pCPT-cGMPS, 10(-5)M). The current study confirmed the inhibitory action of exogenous NO on immunological activation of human mast cells. We also provided evidence for the first time that the activation of the sGC-cGMP-PKG pathways together with the suppression of phosphorylation of MAPKs and NF-kappaB contributed to the mast cell modulating action of NO in human.

Increasing Incidence of Nontuberculous Mycobacteria, Taiwan, 2000-2008

Emerging Infectious Diseases. Feb, 2010  |  Pubmed ID: 20113563

To assess the species distribution and epidemiologic trends of nontuberculous mycobacteria, we examined isolates from patients in Taiwan. During 2000-2008, the proportion increased significantly from 32.3% to 49.8%. Associated disease incidence increased from 2.7 to 10.2 cases per 100,000 patients. Mycobacterium avium complex and M. abscessus were most frequently isolated.

A Contractile Electronic Switch Made of DNA

Journal of the American Chemical Society. Mar, 2010  |  Pubmed ID: 20136076

Double-helical DNA has been shown to conduct both electrons and electron holes, the latter over distances of >20 nm. DNA is thus a material of significant interest for the bottom-up construction of nanocircuitry. Here, we describe a contractile DNA nanoswitch, which can toggle between a structurally extended "off" state and a contracted "on" state, with a 40-fold conductivity difference between the two. To turn on, two short motifs of guanine-guanine mismatches in an otherwise standard double helix synapse to form a conductive G-quadruplex, bypassing an insulating element within the helix. This switch can be turned repeatedly on by treatment with millimolar concentrations of K(+) and turned off by sequestration of the K(+) by a crown ether. Circular dichroism and thymine-thymine photocross-linking experiments reveal that strand orientations within the on state G-quadruplex are wholly antiparallel and that the two conductive double-helices interface with the same face of the quadruplex. Although this DNA nanoswitch is chemically gated, it should be adaptable to other kinds of gating and thus serve as a prototype for increasingly sophisticated and complex electronic devices made of DNA.

Angiotensin II Type 1 Receptor-dependent Oxidative Stress Mediates Endothelial Dysfunction in Type 2 Diabetic Mice

Antioxidants & Redox Signaling. Sep, 2010  |  Pubmed ID: 20136508

The mechanisms underlying the effect of the renin-angiotensin-aldosterone system (RAAS) inhibition on endothelial dysfunction in type 2 diabetes are incompletely understood. This study explored a causal relationship between RAAS activation and oxidative stress involved in diabetes-associated endothelial dysfunction. Daily oral administration of valsartan or enalapril at 10 mg/kg/day to db/db mice for 6 weeks reversed the blunted acetylcholine-induced endothelium-dependent dilatations, suppressed the upregulated expression of angiotensin II type 1 receptor (AT(1)R) and NAD(P)H oxidase subunits (p22(phox) and p47(phox)), and reduced reactive oxygen species (ROS) production. Acute exposure to AT(1)R blocker losartan restored the impaired endothelium-dependent dilatations in aortas of db/db mice and also in renal arteries of diabetic patients (fasting plasma glucose level > or =7.0 mmol/l). Similar observations were also made with apocynin, diphenyliodonium, or tempol treatment in db/db mouse aortas. DHE fluorescence revealed an overproduction of ROS in db/db aortas which was sensitive to inhibition by losartan or ROS scavengers. Losartan also prevented the impairment of endothelium-dependent dilatations under hyperglycemic conditions that were accompanied by high ROS production. The present study has identified an initiative role of AT(1)R activation in mediating endothelial dysfunction of arteries from db/db mice and diabetic patients.

Graphene Nanomesh

Nature Nanotechnology. Mar, 2010  |  Pubmed ID: 20154685

Graphene has significant potential for application in electronics, but cannot be used for effective field-effect transistors operating at room temperature because it is a semimetal with a zero bandgap. Processing graphene sheets into nanoribbons with widths of less than 10 nm can open up a bandgap that is large enough for room-temperature transistor operation, but nanoribbon devices often have low driving currents or transconductances. Moreover, practical devices and circuits will require the production of dense arrays of ordered nanoribbons, which remains a significant challenge. Here, we report the production of a new graphene nanostructure--which we call a graphene nanomesh--that can open up a bandgap in a large sheet of graphene to create a semiconducting thin film. The nanomeshes are prepared using block copolymer lithography and can have variable periodicities and neck widths as low as 5 nm. Graphene nanomesh field-effect transistors can support currents nearly 100 times greater than individual graphene nanoribbon devices, and the on-off ratio, which is comparable with the values achieved in individual nanoribbon devices, can be tuned by varying the neck width. The block copolymer lithography approach used to make the nanomesh devices is intrinsically scalable and could allow for the rational design and fabrication of graphene-based devices and circuits with standard semiconductor processing.

Transforming Growth Factor-beta1 Upregulates the Expression of CXC Chemokine Receptor 4 (CXCR4) in Human Breast Cancer MCF-7 Cells

Acta Pharmacologica Sinica. Mar, 2010  |  Pubmed ID: 20154716

To investigate whether rhTGF-beta1 or a recombinant vector encoding a fusion protein comprising an extracellular domain of TGF-beta receptor II and an IgG Fc fragment) affects the regulation of CXC chemokine receptor 4 (CXCR4) expression in MCF-7 human breast cancer cells.

The Scale of Population Structure in Arabidopsis Thaliana

PLoS Genetics. Feb, 2010  |  Pubmed ID: 20169178

The population structure of an organism reflects its evolutionary history and influences its evolutionary trajectory. It constrains the combination of genetic diversity and reveals patterns of past gene flow. Understanding it is a prerequisite for detecting genomic regions under selection, predicting the effect of population disturbances, or modeling gene flow. This paper examines the detailed global population structure of Arabidopsis thaliana. Using a set of 5,707 plants collected from around the globe and genotyped at 149 SNPs, we show that while A. thaliana as a species self-fertilizes 97% of the time, there is considerable variation among local groups. This level of outcrossing greatly limits observed heterozygosity but is sufficient to generate considerable local haplotypic diversity. We also find that in its native Eurasian range A. thaliana exhibits continuous isolation by distance at every geographic scale without natural breaks corresponding to classical notions of populations. By contrast, in North America, where it exists as an exotic species, A. thaliana exhibits little or no population structure at a continental scale but local isolation by distance that extends hundreds of km. This suggests a pattern for the development of isolation by distance that can establish itself shortly after an organism fills a new habitat range. It also raises questions about the general applicability of many standard population genetics models. Any model based on discrete clusters of interchangeable individuals will be an uneasy fit to organisms like A. thaliana which exhibit continuous isolation by distance on many scales.

Scanning Tunneling Microscopy Investigation of Self-assembled CuPc/F16CuPc Binary Superstructures on Graphite

Langmuir : the ACS Journal of Surfaces and Colloids. Mar, 2010  |  Pubmed ID: 20175573

The self-assembly of the binary molecular system comprising copper(II) phthalocyanine (CuPc) and copper-hexadecafluoro-phthalocyanine (F(16)CuPc) on graphite has been investigated by in situ low-temperature scanning tunneling microscopy (LT-STM). The adsorption of this binary molecular system on graphite results in the formation of a well-ordered chessboardlike nanopattern. The in-plane molecular orientation of the guest CuPc molecules can be tuned by varying the coverage. At low coverage, the sparse CuPc molecules are randomly embedded in the host F(16)CuPc monolayer, possessing two different in-plane orientations; as the CuPc coverage increases, the in-plane molecular orientations of CuPc and F(16)CuPc become unidirectional and a highly ordered chessboardlike pattern forms. Molecular dynamic (MD) simulation results suggest that the selective and directional intermolecular hydrogen bonding determines the in-plane molecular orientation as well as the supramolecular packing arrangement.

Reduced Bone Perfusion in Osteoporosis: Likely Causes in an Ovariectomy Rat Model

Radiology. Mar, 2010  |  Pubmed ID: 20177089

Purpose: To investigate the cause of reduced vertebral perfusion in a rat ovariectomy model. Materials and Methods: Experimental protocol was approved by the local Animal Experiment Ethics Committee. Twenty-two Sprague-Dawley rats were studied. Computed tomographic bone densitometry and magnetic resonance perfusion imaging were performed at baseline and 2, 4, and 8 weeks after ovariectomy (n = 11) or sham surgery (n = 11). Perfusion parameters analyzed were maximum enhancement (E(max)) and enhancement slope (E(slope)). After the animals were sacrificed, the aorta and femoral artery were analyzed for vessel reactivity, and the lumbar vertebrae were analyzed for marrow content. Results: In control rats, bone mineral density (BMD), E(max), and E(slope) remained constant. In ovariectomy rats, a comparable reduction in BMD and the perfusion parameters at two weeks post-ovariectomy (BMD, 9.3%; E(max), 11.6%; E(slope), 9%) was seen 2 weeks after ovariectomy, and further reductions were seen 4 weeks (BMD, 17.5%; E(max), 15.6%; E(slope), 33%) and 8 weeks (BMD, 18.8%; E(max), 14.2%; E(slope), 33%) after ovariectomy. Endothelial dysfunction was observed in both the aorta and femoral artery of the ovariectomy group but not of the control group. Increased marrow fat area was seen in the ovariectomy group (52.9% vs 21.6%; P < .01) owing to an increase in fat cell number. Decreased erythropoetic marrow area (32.5% vs 48.6%; P < .05) was also observed in the ovariectomy group. Conclusion: Reduced bone perfusion occurs in synchrony with reduced BMD. The most likely causes of reduced bone perfusion are a reduction in the amount of erythropoetic marrow and endothelial dysfunction after ovariectomy. (c) RSNA, 2010 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09090608/-/DC1.

Therapeutically Relevant Concentrations of Raloxifene Dilate Pressurized Rat Resistance Arteries Via Calcium-dependent Endothelial Nitric Oxide Synthase Activation

Arteriosclerosis, Thrombosis, and Vascular Biology. May, 2010  |  Pubmed ID: 20185791

Selective estrogen receptor modulators (SERMs) inhibit constriction of mammalian conduit arteries. However, it is unknown whether SERMs at therapeutically achievable concentrations could reduce vascular tone in resistance arteries. The present study aimed to examine roles of Ca(2+) influx in endothelium and endothelial nitric oxide synthase (eNOS) activation in dilatations induced by raloxifene, a second-generation SERM in myogenically active arteries.

Tunable Two-dimensional Binary Molecular Networks

Small (Weinheim an Der Bergstrasse, Germany). Jan, 2010  |  Pubmed ID: 19902433

A novel approach to constructing tunable and robust 2D binary molecular nanostructures on an inert graphite surface is presented. The guest molecules are embedded into a host molecular matrix and constrained via the formation of multiple intermolecular hydrogen bonds. By varying the binary molecular ratio and the molecular geometry, various molecular arrays with tunable intermolecular distances are fabricated. The results suggest a promising route for the fabrication of ordered and stable molecular nanostructure arrays for molecular sensors, molecular spintronic devices, and molecular p-n nanojunctions.

Pharmacokinetics and Safety of Ginsenoside Rd Following a Single or Multiple Intravenous Dose in Healthy Chinese Volunteers

Journal of Clinical Pharmacology. Mar, 2010  |  Pubmed ID: 19940231

The pharmacokinetics and safety of ginsenoside Rd (Rd) were assessed in healthy Chinese volunteers. In the single-dose study, a randomized, open-label, 3-way crossover design was used. Participants were assigned to receive 10, 45, or 75 mg Rd by intravenous infusion, with a 2-week washout period between dosing periods. Plasma levels of Rd were found to be proportional to dose, with the mean C(max) and AUC(0-infinity) ranging from 2.8 to 19.3 mg/L and 27.9 to 212.5 mg x h/L over the dose range studied. Ginsenoside Rd was slowly cleared from plasma (t(1/2Z) = 17.7-19.3 hours). In the multiple-dose study, 10 mg Rd was administered once daily for 6 days. Slight drug accumulation was noted. The mean steady-state C(max), AUC(0-infinity), and AUC(ss) were 4.0 mg/L, 51.7 mg x h/L, and 26.4 mg x h/L, respectively. The t(1/2Z) was 20.5 hours, which was similar to the single-dose value. Ginsenoside Rd was well tolerated with no pattern of dose-related adverse events. It had a favorable pharmacokinetic and safety profile that enables the drug to be explored in future clinical studies that target patients with acute ischemic stroke.

Single-layer Graphene on Al2O3/Si Substrate: Better Contrast and Higher Performance of Graphene Transistors

Nanotechnology. Jan, 2010  |  Pubmed ID: 19946170

The fact that single-layer graphene can be visualized on 300 nm SiO(2)/Si substrate using an optical microscope has enabled the facile fabrication of single-layer graphene devices for fundamental studies and potential applications. Here we report on an Al(2)O(3)/Si substrate for the fabrication of graphene devices with better contrast and higher performance. Our studies show that the contrast of single-layer graphene on 72 nm Al(2)O(3)/Si substrate is much better than that of single-layer graphene on 300 nm SiO(2)/Si substrate. Moreover, the transconductance of single-layer graphene transistors on Al(2)O(3)/Si substrate shows a more than sevenfold increase, due to the smaller dielectric thickness and higher dielectric constant in a 72 nm Al(2)O(3) film. These studies demonstrate a new and superior substrate for the fabrication of graphene transistors, and are of significance for both fundamental studies and technological applications.

CNGA2 Contributes to ATP-induced Noncapacitative Ca2+ Influx in Vascular Endothelial Cells

Journal of Vascular Research. 2010  |  Pubmed ID: 19729961

ATP can activate several Ca(2+) influx channels in vascular endothelial cells. For example, it stimulates TRPC channels via capacitative and noncapacitative Ca(2+) entry (CCE and non-CCE, respectively) mechanisms; it also directly acts on P2X purinoceptors, resulting in Ca(2+) influx. In the present study, we tested the hypothesis that cyclic nucleotide-gated (CNG) channels also contribute to ATP-induced non-CCE.

Prostaglandins in Action Indispensable Roles of Cyclooxygenase-1 and -2 in Endothelium-dependent Contractions

Advances in Pharmacology (San Diego, Calif.). 2010  |  Pubmed ID: 21081215

Endothelium regulates local vascular tone by means of releasing relaxing and contracting factors, of which the latter have been found to be elevated in vascular pathogenesis of hypertension, diabetes, hypercholesterolemia, and aging. Endothelium-derived contracting factors (EDCFs) are mainly metabolites of arachidonic acid generated by cyclooxygenase (COX), as vasodilatations in patients with hypertension, metabolic diseases, or advancing age are improved by acute treatment with COX inhibitor indomethacin. COX is presented in two isoforms, COX-1 and COX-2, with the former regarded as constitutive and the latter mainly expressed upon induction. Experiments with animal models of vascular dysfunctions, however, reveal that both isoforms have similar capacity to participate in endothelium-dependent contractions, with augmented expression and activity. COX-derived prostaglandin (PG) H(2), PGF(2α), PGE(2), prostacyclin (PGI(2)), and thromboxane A(2) (TxA(2)) are the proposed EDCFs that mediate endothelium-dependent contractions via the activation of thromboxane-prostanoid (TP) receptor in various vascular beds from different species. Although COX inhibition seems to be a possible strategy in combating COX-associated vascular complications, the incidence of adverse cardiovascular effects of Vioxx has greatly antagonized this concept. Further review of COX inhibitors is required, especially toward the selectivity of coxibs and whether it directly inhibits prostacyclin synthase activity. Meanwhile, TP receptor antagonism may emerge as a therapeutic alternative to reverse prostanoid-mediated vascular dysregulations.

A Coastal Cline in Sodium Accumulation in Arabidopsis Thaliana is Driven by Natural Variation of the Sodium Transporter AtHKT1;1

PLoS Genetics. Nov, 2010  |  Pubmed ID: 21085628

The genetic model plant Arabidopsis thaliana, like many plant species, experiences a range of edaphic conditions across its natural habitat. Such heterogeneity may drive local adaptation, though the molecular genetic basis remains elusive. Here, we describe a study in which we used genome-wide association mapping, genetic complementation, and gene expression studies to identify cis-regulatory expression level polymorphisms at the AtHKT1;1 locus, encoding a known sodium (Na(+)) transporter, as being a major factor controlling natural variation in leaf Na(+) accumulation capacity across the global A. thaliana population. A weak allele of AtHKT1;1 that drives elevated leaf Na(+) in this population has been previously linked to elevated salinity tolerance. Inspection of the geographical distribution of this allele revealed its significant enrichment in populations associated with the coast and saline soils in Europe. The fixation of this weak AtHKT1;1 allele in these populations is genetic evidence supporting local adaptation to these potentially saline impacted environments.

[Characterizations of Avian Influenza Virus H6N6 Subtype Isolated from Domestic Muscovy Duck]

Wei Sheng Wu Xue Bao = Acta Microbiologica Sinica. Sep, 2010  |  Pubmed ID: 21090254

To enrich the epidemiologic data of the waterfowl origin avian influenza virus (AIV).

[Clinical and Pathological Characteristics of Atypical Fabry Disease]

Zhonghua Xin Xue Guan Bing Za Zhi. Sep, 2010  |  Pubmed ID: 21092662

Photocatalytic Properties of Porous Silicon Nanowires

Journal of Materials Chemistry. 2010  |  Pubmed ID: 22190767

Porous silicon nanowires are synthesized through metal assisted wet-chemical etch of highly-doped silicon wafer. The resulted porous silicon nanowires exhibit a large surface area of 337 m(2)·g(-1) and a wide spectrum absorption across the entire ultraviolet, visible and near infrared regime. We further demonstrate that platinum nanoparticles can be loaded onto the surface of the porous silicon nanowires with controlled density. These combined advancements make the porous silicon nanowires an interesting material for photocatalytic applications. We show that the porous silicon nanowires and platinum nanoparticle loaded porous silicon nanowires can be used as effective photocatalysts for photocatalytic degradation of organic dyes and toxic pollutants under visible irradiation, and thus are of significant interest for organic waste treatment and environmental remediation.

Complementary and Miscellaneous Interventions for Nocturnal Enuresis in Children

Cochrane Database of Systematic Reviews (Online). 2011  |  Pubmed ID: 22161390

Nocturnal enuresis (bedwetting) is a socially disruptive and stressful condition which affects around 15% to 20% of five year olds, and up to 2% of young adults.

TRPV1 Activation Improves Exercise Endurance and Energy Metabolism Through PGC-1α Upregulation in Mice

Cell Research. Dec, 2011  |  Pubmed ID: 22184011

Impaired aerobic exercise capacity and skeletal muscle dysfunction are associated with cardiometabolic diseases. Acute administration of capsaicin enhances exercise endurance in rodents, but the long-term effect of dietary capsaicin is unknown. The capsaicin receptor, the transient receptor potential vanilloid 1 (TRPV1) cation channel has been detected in skeletal muscle, the role of which remains unclear. Here we report the function of TRPV1 in cultured C2C12 myocytes and the effect of TRPV1 activation by dietary capsaicin on energy metabolism and exercise endurance of skeletal muscles in mice. In vitro, capsaicin increased cytosolic free calcium and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression in C2C12 myotubes through activating TRPV1. In vivo, PGC-1α in skeletal muscle was upregulated by capsaicin-induced TRPV1 activation or genetic overexpression of TRPV1 in mice. TRPV1 activation increased the expression of genes involved in fatty acid oxidation and mitochondrial respiration, promoted mitochondrial biogenesis, increased oxidative fibers, enhanced exercise endurance and prevented high-fat diet-induced metabolic disorders. Importantly, these effects of capsaicin were absent in TRPV1-deficient mice. We conclude that TRPV1 activation by dietary capsaicin improves energy metabolism and exercise endurance by upregulating PGC-1α in skeletal muscles. The present results indicate a novel therapeutic strategy for managing metabolic diseases and improving exercise endurance.Cell Research advance online publication 20 December 2011; doi:10.1038/cr.2011.205.

Genotypic Variation in Phosphorus Acquisition from Sparingly Soluble P Sources is Related to Root Morphology and Root Exudates in Brassica Napus

Science China. Life Sciences. Dec, 2011  |  Pubmed ID: 22227906

Genotypic variations in the adaptive response to low-phosphorus (P) stress and P-uptake efficiency have been widely reported in many crops. We conducted a pot experiment to evaluate the P-acquisition ability of two rapeseed (Brassica napus) genotypes supplied with two sparingly soluble sources of P, Al-P and Fe-P. Then, the root morphology, proton concentrations, and carboxylate content were investigated in a solution experiment to examine the genotypic difference in P-acquisition efficiency. Both genotypes produced greater biomass and accumulated more P when supplied with Al-P than when supplied with Fe-P. The P-efficient genotype 102 showed a significantly greater ability to deplete sparingly soluble P from the rhizosphere soil because of its greater biomass and higher P uptake compared with those of the P-inefficient genotype 105. In the solution experiment, the P-efficient genotype under low-P conditions developed dominant root morphological traits, and it showed more intensive rhizosphere acidification because of greater H(+) efflux, higher H(+)-ATPase activity, and greater exudation of carboxylates than the P-inefficient genotype. Thus, a combination of morphological and physiological mechanisms contributed to the genotypic variation in the utilization of different sparingly soluble P sources in B. napus.

Contrastive Analysis of the Raman Spectra of Polychlorinated Benzene: Hexachlorobenzene and Benzene

Sensors (Basel, Switzerland). 2011  |  Pubmed ID: 22247678

Detection of persistent pollutants such as polychlorinated benzene in environment in trace amounts is challenging, but important. It is more difficult to distinguish homologues and isomers of organic pollutantd when present in trace amounts because of their similar physical and chemical properties. In this work we simulate the Raman spectra of hexachlorobenzene and benzene, and figure out the vibration mode of each main peak. The effect on the Raman spectrum of changing substituents from H to Cl is analyzed to reveal the relations between the Raman spectra of homologues and isomers of polychlorinated benzene, which should be helpful for distinguishing one kind of polychlorinated benzene from its homologues and isomers by surface enhanced Raman scattering.

Synthesis and Electric Properties of Dicobalt Silicide Nanobelts

Chemical Communications (Cambridge, England). Jan, 2011  |  Pubmed ID: 21103514

Single crystalline Co(2)Si nanobelts were synthesized for the first time. Temperature-dependent electrical transport studies show the Co(2)Si nanobelts exhibit metallic behavior with a large negative magnetoresistance over 10% at low temperature, which may be attributed to alignment of the spins in surface cobalt atoms.

Requirement of Regulated Endocrine-specific Protein-18 for Development and Expression of Regulated Endocrine-specific Protein-18 Isoform C in Mice

Molecular Biology Reports. Apr, 2011  |  Pubmed ID: 21104147

Regulated endocrine-specific protein-18 (RESP18) is distributed mainly in the peripheral endocrine and neuroendocrine tissues. The expression of RESP18 protein is regulated by physiological factors, such as blood glucose or dopaminergic drugs, but its functions remain unclear. In this study, to explore the biological functions of RESP18 in vivo, we generated RESP18 heterozygous deficient mice, and further found RESP18 was essential for embryonic development. In addition, we cloned a new isoform of mouse RESP18 by reverse transcription-polymerase chain reaction (RT-PCR), and denominated it as RESP18-c. Mouse RESP18-c, by skipping exon4 (43 bp in length), encodes a shorter protein of 120 amino acid residues. The distribution of RESP18-c mRNA is similar with that of RESP18 mRNA in the peripheral tissues and brains of mice.

Diagnostic Value of 16 Cellular Tumor Markers for Metastatic Thyroid Cancer: an Immunohistochemical Study

Anticancer Research. Oct, 2011  |  Pubmed ID: 21965758

The prognosis for thyroid cancer differs between metastatic and non-metastatic cases. To identify biomarkers useful for thyroid cancer diagnosis and to establish a marker panel for the early detection of metastatic thyroid carcinoma, this study compared histomorphological features and biomarker expression profiles in thyroid carcinomas according to pathological diagnoses.

Effect of Hydrogen Peroxide and Superoxide Anions on Cytosolic Ca2+: Comparison of Endothelial Cells from Large-sized and Small-sized Arteries

PloS One. 2011  |  Pubmed ID: 21966527

We compared the Ca(2+) responses to reactive oxygen species (ROS) between mouse endothelial cells derived from large-sized arteries, aortas (aortic ECs), and small-sized arteries, mesenteric arteries (MAECs). Application of hydrogen peroxide (H(2)O(2)) caused an increase in cytosolic Ca(2+) levels ([Ca(2+)](i)) in both cell types. The [Ca(2+)](i) rises diminished in the presence of U73122, a phospholipase C inhibitor, or Xestospongin C (XeC), an inhibitor for inositol-1,4,5-trisphosphate (IP(3)) receptors. Removal of Ca(2+) from the bath also decreased the [Ca(2+)](i) rises in response to H(2)O(2). In addition, treatment of endothelial cells with H(2)O(2) reduced the [Ca(2+)](i) responses to subsequent challenge of ATP. The decreased [Ca(2+)](i) responses to ATP were resulted from a pre-depletion of intracellular Ca(2+) stores by H(2)O(2). Interestingly, we also found that Ca(2+) store depletion was more sensitive to H(2)O(2) treatment in endothelial cells of mesenteric arteries than those of aortas. Hypoxanthine-xanthine oxidase (HX-XO) was also found to induce [Ca(2+)](i) rises in both types of endothelial cells, the effect of which was mediated by superoxide anions and H(2)O(2) but not by hydroxyl radical. H(2)O(2) contribution in HX-XO-induced [Ca(2+)](i) rises were more significant in endothelial cells from mesenteric arteries than those from aortas. In summary, H(2)O(2) could induce store Ca(2+) release via phospholipase C-IP(3) pathway in endothelial cells. Resultant emptying of intracellular Ca(2+) stores contributed to the reduced [Ca(2+)](i) responses to subsequent ATP challenge. The [Ca(2+)](i) responses were more sensitive to H(2)O(2) in endothelial cells of small-sized arteries than those of large-sized arteries.

The Development of a Rapid SYBR Green I-based Quantitative PCR for Detection of Duck Circovirus

Virology Journal. 2011  |  Pubmed ID: 21978576

This report describes a one-step real-time polymerase chain reaction assay based on SYBR Green I for detection of a broad range of duck circovirus (DuCV). Align with all DuCV complete genome sequences and other Genus Circovirus download from the GenBank (such as goose circovirus, pigeon circovirus), the primers targets to the replicate gene of DuCV were designed. The detection assay was linear in the range of 1.31 × 102-1.31 × 107 copies/μL. The reaction efficiency of the assay using the slope (the slope was -3.349) and the Y-intercept was 37.01 from the linear equation was estimated to be 0.99 and the correlation coefficient (R2) was 0.993. A series of experiments were carried out to assess the reproducibility, sensitivity, and specificity of the assay, following by the low intra-assay and inter-assay CVs for CT values obtained with the standard plasmids. The intra-assay CVs were equal or less than 1.89% and the inter-assay CVs were equal or less than 1.26%. There was no cross-reaction occurred with nucleic acids extracted from RA (Riemerella anatipestifer), E. coli (Escherichia coli), Duck Cholera (Pasteurella multocida), Avian influenza virus, avian paramyxovirus, Muscovy duck parvovirus, Duck reovirus, Duck hepatitis A virus as control templates. The nucleic acids extracted from samples of healthy ducks were used as negative controls. The assay was specific and reproducible. The established real time PCR was used to detect 45 DuCV-negative samples, which were tested using conventional PCR under the developed optimal conditions, each 15 for embryonated eggs, non-embryonated budgerigar eggs, newly hatched duck, the mixture of the lung, liver, spleen which were analysis for the presence of DuCV DNA, to conform that whether the DuCV can be transmitted vertically. Meanwhile, no positive result was shown by the real-time PCR method. The SYBR Green I-based quantitative PCR can therefore be practically used as an alternative diagnostic tool and a screening method for ducks infected with duck circovirus.

Epidemiological Investigation and Genome Analysis of Duck Circovirus in Southern China

Virologica Sinica. Oct, 2011  |  Pubmed ID: 21979568

Duck circovirus (DuCV), a potential immunosuppressive virus, was investigated in Southern China from March 2006 to December 2009 by using a polymerase chain reaction (PCR) based method. In this study, a total of 138 sick or dead duck samples from 18 different farms were examined with an average DuCV infection rate of ∼35%. It was found that ducks between the ages of 40∼60 days were more susceptible to DuCV. There was no evidence showing that the DuCV virus was capable of vertical transmission. Farms with positive PCR results exhibited no regularly apparent clinical abnormalities such as feathering disorders, growth retardation or lower-than-average weight. The complete genomes of 9 strains from Fujian Province and 1 from Zhejiang Province were sequenced and analyzed. The 10 DuCV genomes, compared with others genomes downloaded from GenBank, ranged in size from 1988 to 1996 base pairs, with sequence identities ranging from 83.2% to 99.8%. Phylogenetic analysis based on genome sequences demonstrated that DuCVs can be divided into two distinct genetic genotypes, Group I (the Euro-USA lineage) and Group II (the Taiwan lineage), with approximately 10.0% genetic difference between the two types. Molecular epidemiological data suggest there is no obvious difference among DuCV strains isolated from different geographic locations or different species, including Duck, Muscovy duck, Mule duck, Cheery duck, Mulard duck and Pekin duck.

The Growth and Applications of Silicides for Nanoscale Devices

Nanoscale. Oct, 2011  |  Pubmed ID: 21987008

Metal silicides have been used in silicon technology as contacts to achieve high device performance and desired device functions. The growth and applications of silicide materials have recently attracted increasing interest for nanoscale device applications. Nanoscale silicide materials have been demonstrated with various synthetic approaches. Solid state reaction wherein high quality silicides form through diffusion of metal atoms into silicon nano-templates and the subsequent phase transformation caught significant attention for the fabrication of nanoscale Si devices. Very interestingly, studies on the diffusion and phase transformation processes at the nanoscale have indicated possible deviations from the bulk and the thin film system. Here we present a review of fabrication, growth kinetics, electronic properties and device applications of nanoscale silicides formed through solid state reaction.

Tembusu Virus in Ducks, China

Emerging Infectious Diseases. Oct, 2011  |  Pubmed ID: 22000358

In China in 2010, a disease outbreak in egg-laying ducks was associated with a flavivirus. The virus was isolated and partially sequenced. The isolate exhibited 87%-91% identity with strains of Tembusu virus, a mosquito-borne flavivirus of the Ntaya virus group. These findings demonstrate emergence of Tembusu virus in ducks.

Transgenic Mice Over-expressing ET-1 in the Endothelial Cells Develop Systemic Hypertension with Altered Vascular Reactivity

PloS One. 2011  |  Pubmed ID: 22096514

Endothelin-1 (ET-1) is a potent vasoconstrictor involved in the regulation of vascular tone and implicated in hypertension. However, the role of small blood vessels endothelial ET-1 in hypertension remains unclear. The present study investigated the effect of chronic over-expression of endothelial ET-1 on arterial blood pressure and vascular reactivity using transgenic mice approach. Transgenic mice (TET-1) with endothelial ET-1 over-expression showed increased in ET-1 level in the endothelial cells of small pulmonary blood vessels. Although TET-1 mice appeared normal, they developed mild hypertension which was normalized by the ET(A) receptor (BQ123) but not by ET(B) receptor (BQ788) antagonist. Tail-cuff measurements showed a significant elevation of systolic and mean blood pressure in conscious TET-1 mice. The mice also exhibited left ventricular hypertrophy and left axis deviation in electrocardiogram, suggesting an increased peripheral resistance. The ionic concentrations in the urine and serum were normal in 8-week old TET-1 mice, indicating that the systemic hypertension was independent of renal function, although, higher serum urea levels suggested the occurrence of kidney dysfunction. The vascular reactivity of the aorta and the mesenteric artery was altered in the TET-1 mice indicating that chronic endothelial ET-1 up-regulation leads to vascular tone imbalance in both conduit and resistance arteries. These findings provide evidence for the role of spatial expression of ET-1 in the endothelium contributing to mild hypertension was mediated by ET(A) receptors. The results also suggest that chronic endothelial ET-1 over-expression affects both cardiac and vascular functions, which, at least in part, causes blood pressure elevation.

Development of Viral Vectors for Gene Therapy for Chronic Pain

Pain Research and Treatment. 2011  |  Pubmed ID: 22110937

Chronic pain is a major health concern that affects millions of people. There are no adequate long-term therapies for chronic pain sufferers, leading to significant cost for both society and the individual. The most commonly used therapy for chronic pain is the application of opioid analgesics and nonsteroidal anti-inflammatory drugs, but these drugs can lead to addiction and may cause side effects. Further studies of the mechanisms of chronic pain have opened the way for development of new treatment strategies, one of which is gene therapy. The key to gene therapy is selecting safe and highly efficient gene delivery systems that can deliver therapeutic genes to overexpress or suppress relevant targets in specific cell types. Here we review several promising viral vectors that could be applied in gene transfer for the treatment of chronic pain and further discuss the possible mechanisms of genes of interest that could be delivered with viral vectors for the treatment of chronic pain.

Trans-Diaqua-bis-[4-carboxy-5-carboxyl-ato-2-(pyridin-1-ium-4-yl)-1H-imidazol-1-ido-κN,O]cobalt(II)

Acta Crystallographica. Section E, Structure Reports Online. Sep, 2011  |  Pubmed ID: 22058867

In the title compound, [Co(C(10)H(6)N(3)O(4))(2)(H(2)O)(2)], the Co(II) ion is coordinated by two O atoms of two water mol-ecules, two imidazole nitro-gen atoms and two carboxyl-ate O atoms of the two trans-standing chelate ligands, displaying a distorted octa-hedral coordination geometry. A three-dimensional supra-molecular framework is generated through N-H⋯O, O-H⋯N and O-H⋯O hydrogen-bonding inter-actions.

Plasmon Resonance Enhanced Multicolour Photodetection by Graphene

Nature Communications. 2011  |  Pubmed ID: 22146398

Graphene has the potential for high-speed, wide-band photodetection, but only with very low external quantum efficiency and no spectral selectivity. Here we report a dramatic enhancement of the overall quantum efficiency and spectral selectivity that enables multicolour photodetection, by coupling graphene with plasmonic nanostructures. We show that metallic plasmonic nanostructures can be integrated with graphene photodetectors to greatly enhance the photocurrent and external quantum efficiency by up to 1,500%. Plasmonic nanostructures of variable resonance frequencies selectively amplify the photoresponse of graphene to light of different wavelengths, enabling highly specific detection of multicolours. Being atomically thin, graphene photodetectors effectively exploit the local plasmonic enhancement effect to achieve a significant enhancement factor not normally possible with traditional planar semiconductor materials.

[Effects of Exogenous Abscisic Acid (ABA) on the Photosynthesis and Chlorophyll Fluorescence Parameters of Tripterygium Wilfordii Seedlings Exposed to Low Temperature]

Ying Yong Sheng Tai Xue Bao = The Journal of Applied Ecology / Zhongguo Sheng Tai Xue Xue Hui, Zhongguo Ke Xue Yuan Shenyang Ying Yong Sheng Tai Yan Jiu Suo Zhu Ban. Dec, 2011  |  Pubmed ID: 22384581

Taking one year-old Tripterygium wilfordii cutting seedlings as test materials, this paper studied the effects of foliar spraying 0, 5, 10, 15, 20, and 25 mg x L(-1) of abscisic acid (ABA) on the leaf photosynthesis and chlorophyll fluorescence characteristics of the seedlings under low temperature stress. Spraying 20 mg x L(-1) of ABA increased the cold- resistance of the seedlings significantly, manifesting in the slowing down of the decrease amplitudes of leaf net photosynthetic rate (P(n)), transpiration rate (T(r)), stomatal conductance (g(s)), and intercellular CO2 concentration (C(i)) and the increase of photosynthetic capacity. After 6 days exposure to low temperature, the initial fluorescence (F(o)) decreased with increasing concentration of applied ABA, the maximum fluorescence (F(m)) and maximal photochemical yield (F(v)/F(m)) increased, the actual photochemical efficiency of system II (phi(PSII)) and photochemical quenching coefficient (q(P)) increased after an initial decrease, and the non-photochemical quenching coefficient (q(N)) showed a 'decreasing-increasing-decreasing' trend. The P(n), g(s), q(P), F(m), and F(v)/F(m) reached their peak values at 20 mg x L(-1) of ABA. In all treatments, with the increase of photosynthetically active radiation (PAR), the relative electron transport rate (rETR) increased first and decreased then, reached the peak when the PAR was 395 micromol x m(-2) x s(-1), and the peak value of the rETR in treatments 25 and 20 mg x L(-1) of ABA was 17.1% and 5.2% higher than that of the control, respectively. The light response curves of the psi(PSII) decreased with increasing PAR, whereas those of q(N) performed in adverse.

Rapid Detection of Polychlorinated Biphenyls at Trace Levels in Real Environmental Samples by Surface-enhanced Raman Scattering

Sensors (Basel, Switzerland). 2011  |  Pubmed ID: 22346675

Detection of trace levels of persistent pollutants in the environment is difficult but significant. Organic pollutant homologues, due to their similar physical and chemical properties, are even more difficult to distinguish, especially in trace amounts. We report here a simple method to detect polychlorinated biphenyls (PCBs) in soil and distilled spirit samples by the surface-enhanced Raman scattering technique using Ag nanorod arrays as substrates. By this method, polychlorinated biphenyls can be detected to a concentration of 5 μg/g in dry soil samples within 1 minute. Furthermore, based on simulation and understanding of the Raman characteristics of PCBs, we recognized homologues of tetrachlorobiphenyl by using the surface-enhance Raman scattering method even in trace amounts in acetone solutions, and their characteristic Raman peaks still can be distinguished at a concentration of 10(-6) mol/L. This study provides a fast, simple and sensitive method for the detection and recognition of organic pollutants such as polychlorinated biphenyls.

Ox-LDL Modifies the Behaviour of Bone Marrow Stem Cells and Impairs Their Endothelial Differentiation Via Inhibition of Akt Phosphorylation

Journal of Cellular and Molecular Medicine. Feb, 2011  |  Pubmed ID: 19863696

This study was to investigate the effect of oxidized low-density lipoprotein (ox-LDL) on the behaviour of bone marrow stem cells and their endothelial differentiation as well as the underlying mechanisms. Adult rat bone marrow multipotent progenitor cells (MAPCs) were incubated with ox-LDL for up to 2 weeks. Ox-LDL treatment resulted in a time- and dose-dependent reduction of MAPC population in culture through a combination of decreased cell proliferation and increased apoptosis. The expression of stem cell marker Oct-4 was significantly suppressed in MAPCs by ox-LDL in a dose- and time-dependant manner. Endothelial differentiation of MAPCs was substantially inhibited by ox-LDL with markedly decreased expression of endothelial markers vWF, Flk-1 and CD31, as well as impaired in vitro vascular structure formation. Ox-LDL-induced apoptosis and inhibition of Oct-4 expression, cell proliferation and endothelial differentiation of MAPCs were associated with significant inhibition of Akt phosphorylation. Akt overexpression in MAPCs transfected with a constitutively active Akt completely reversed the effects of ox-LDL on MAPCs including enhanced apoptosis, decreased cell proliferation, suppressed Oct-4 expression and endothelial differentiation as well as in vitro vascular structure formation. In conclusion, ox-LDL promotes apoptosis and inhibits Oct-4 expression and self-renewal of MAPCs, and impairs their endothelial differentiation via suppression of Akt signalling.

Dual Actions of Cilnidipine in Human Internal Thoracic Artery: Inhibition of Calcium Channels and Enhancement of Endothelial Nitric Oxide Synthase

The Journal of Thoracic and Cardiovascular Surgery. Apr, 2011  |  Pubmed ID: 20599230

Cilnidipine is a novel, long-action L/N-type dihydropyridine calcium channel blocker that has recently been used for antihypertensive therapy. We investigated the vasorelaxation effect of cilnidipine with regard to its calcium channel blockage and nitric oxide-cyclic guanosine monophosphate-dependent mechanism in human internal thoracic artery.

Isolation and Characterization of a Reovirus Causing Spleen Necrosis in Pekin Ducklings

Veterinary Microbiology. Mar, 2011  |  Pubmed ID: 20970930

High rates of mortality for Pekin ducklings have been recorded in several duck farms in China since 2006. Dead ducklings were characterized by spleen necrosis, suggesting microbial infection as a cause of disease. Laboratory investigations led to the isolation of a virus strain from the spleen tissues of dead ducklings, designated DRV-HC. Subsequent experimental infections with DRV-HC resulted in marked spleen necrosis in the ducklings similar to those observed in the natural outbreaks. Electron microscopy of the cultured DRV-HC revealed viral particles that were non-enveloped and icosahedral with a mean diameter of approximately 72 nm. Agar gel precipitating tests showed that the isolate shared a common group-specific antigen with chicken reovirus S1133. DNA sequencing revealed that this isolate was closely related to Muscovy duck reoviruses. Experimental infection with DRV-HC resulted in death of young chicks with necrotic foci in the liver and spleen. To the best of our knowledge, this is the first report of the isolation of a duck reovirus with high virulence in Pekin ducklings and SPF chickens.

Dietary Calcium Decreases Plasma Cholesterol by Down-regulation of Intestinal Niemann-Pick C1 Like 1 and Microsomal Triacylglycerol Transport Protein and Up-regulation of CYP7A1 and ABCG 5/8 in Hamsters

Molecular Nutrition & Food Research. Feb, 2011  |  Pubmed ID: 20715096

It has been shown that calcium supplementation favorably modifies plasma lipoprotein profile in postmenopausal women. The present study investigated the interaction of dietary calcium with genes of transporters, receptors and enzymes involved in cholesterol metabolism.

Characteristics and Health Impacts of VOCs and Carbonyls Associated with Residential Cooking Activities in Hong Kong

Journal of Hazardous Materials. Feb, 2011  |  Pubmed ID: 21112148

Cooking emission samples collected in two residential kitchens were compared where towngas (denoted as dwelling A) and liquefied petroleum gas (LPG) (denoted as dwelling B) were used as cooking fuels. A total of 50 different volatile organic compounds (VOCs) were quantified during the 90 min cooking periods. None of any carcinogenic compounds like formaldehyde, acetaldehyde or benzene are detected in the raw fuels, confirming that those are almost entirely derived due to cooking activity alone. Alkenes accounted for approximately 53% of the total measured VOCs collected at dwelling A, while alkanes contributed approximately 95% of the VOCs at dwelling B during the cooking periods. The concentration of aromatic hydrocarbons such as benzene and toluene also increased during the cooking periods. The total amount of carbonyls emitted from the cooking processes at dwelling A (2708 μg) is three times higher than that at dwelling B (793 μg). Acetaldehyde was the most abundant carbonyl at the dwelling A but its emission was insignificant at the dwelling B. Carcinogenic risks on chronic exposure to formaldehyde, acetaldehyde, and benzene for housewives and domestic helpers were evaluated. Formaldehyde accounts for 68% and close to 100% of lifetime cancer risks at dwelling A and B, respectively.

Cardioprotective Effects of Epigallocatechin-3-gallate Against Doxorubicin-induced Cardiomyocyte Injury

European Journal of Pharmacology. Feb, 2011  |  Pubmed ID: 21114975

Doxorubicin-induced generation of reactive oxygen species is a leading cause of cardiomyopathy, the major side-effect limiting the clinical use of this anti-cancer drug. Epigallocatechin-3-gallate (EGCG), a main catechin in green tea that possesses a strong antioxidant property. This study aims to investigate whether EGCG can protect cardiac myocytes against doxorubicin-induced myocyte injury. Myocyte viability was measured with an MTT assay. Reactive oxygen species were measured with fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate. Myocyte shortening and intracellular Ca(2+) levels were determined with a spectrofluorometer connected to a video edge detection system. EGCG concentration-dependently increased cell viability and inhibited the generation of reactive oxygen species in doxorubicin-treated myocytes. Doxorubicin significantly decreased the amplitudes of cell shortening, the maximum velocity of cell contraction (+dl/dt) and relaxation (-dl/dt) in electrically-stimulated myocytes in the presence or absence of isoprenaline, which was attenuated by EGCG. The present data suggest that EGCG may protect myocytes against oxidative stress-induced cellular injury in doxorubicin-treated cardiac myocytes. The effect of EGCG on Ca(2+) handling was also examined. EGCG increased the amplitudes of both electrically- and caffeine-induced Ca(2+) transients in doxorubicin-treated myocytes, suggesting that EGCG may reverse doxorubicin-induced intracellular Ca(2+) depletion in the sarcoplasmic reticulum. We found in the present study that EGCG may protect heart against doxorubicin-induced myocyte injury by improving Ca(2+) handling through scavenging reactive oxygen species. Our results imply that EGCG may be used together with doxorubicin to minimize its cardiac toxic effects.

The Model of Rough Wetting for Hydrophobic Steel Meshes That Mimic Asparagus Setaceus Leaf

Journal of Colloid and Interface Science. Feb, 2011  |  Pubmed ID: 21115180

A comprehensive analytical model is proposed to provide a relationship between the macroscopic roughness and contact angle, which is used to develop macroscopic rough surface and to create biomimetic superhydrophobic surfaces. Using chemical surface modification of steel wires, an artificial hydrophobic surface was prepared. A steel mesh mimicking the Asparagus setaceus leaf was created by lowing the surface energy and enhancing macroscopic surface roughness. Water contact angles as high as 129.0° were achieved on the steel mesh with 200μm×200μm pore size. Bad agreement between the predictions based on the original Cassie-Baxter model and experiments was obtained. The version of the Cassie-Baxter model in current use could not be applied to this problem since the roughness magnitude changes from nano/microscopic to macroscopic. A new model, called macroscopic Cassie-Baxter (MCB) model, is constructed by the introduction of contact area density (δ) to original Cassie-Baxter model. It is shown that the measured data is in good agreement with the predicted data based on the MCB model. This model not only for solving macroscopic hydrophobic problems of meshes, but also can be used to solve that of other materials with macroscopic roughness.

Genomic Sequence of an Avian Paramyxovirus Type 1 Strain Isolated from Muscovy Duck (Cairina Moschata) in China

Archives of Virology. Mar, 2011  |  Pubmed ID: 21152939

The complete sequence of an avian paramyxovirus type 1 (APMV-1) strain, FP1/02, isolated from Muscovy duck in China, was determined. Sequence analysis indicated that the complete genome of strain FP1/02 contained 15,192 nucleotides (nt), following the rule of six. The genome contained an extra 6-nt insertion in the non-coding region of the NP gene when compared with other APMV-1 strains, such as strains La Sota and Beaudette C. The cleavage site of the F protein was (112)R-R-Q-K-R↓F(117), indicating that the FP1/02 strain was virulent, but the morbidity and mortality varied with the species of duck. Genotypic analysis based on the F gene revealed that APMV-1 FP1/02 was a member of genotype VII. Phylogenetic analysis showed that the FP1/02 strain shared high identity with other APMV-1 strains such as ZJ1, SF02 and NA-1 isolated from geese.

Telmisartan Inhibits Vasoconstriction Via PPARγ-dependent Expression and Activation of Endothelial Nitric Oxide Synthase

Cardiovascular Research. Apr, 2011  |  Pubmed ID: 21156825

Telmisartan activates peroxisome proliferator-activated receptor-γ (PPARγ) in addition to serving as an angiotensin II type 1 receptor (AT(1)R) blocker. The PPARγ activity of telmisartan on resistance arteries has remained largely unknown. The present study investigated the hypothesis that telmisartan inhibited vascular tension in mouse mesenteric resistance arteries, which was attributed to an increased nitric oxide (NO) production through the PPARγ-dependent augmentation of expression and activity of endothelial nitric oxide synthase (eNOS).

Molecular Trapping on Two-dimensional Binary Supramolecular Networks

Journal of the American Chemical Society. Feb, 2011  |  Pubmed ID: 21186797

Molecular preferential adsorption on molecular patterned surfaces via specific intermolecular interactions provides an efficient route to construct ordered organic nanostructures for future nanodevices. Here, we demonstrate the preferential trapping of second-layer molecules atop two-dimensional binary supramolecular networks, F(16)CuPc on DIP:F(16)CuPc and 6P:F(16)CuPc systems, respectively, through intermolecular π-π interactions. The formation of the second-layer supramolecular nanostructures, individual molecular dots or linear molecular chains, can be controlled by the underlying molecular networks.

Rescue of Mesangial Cells from High Glucose-induced Over-proliferation and Extracellular Matrix Secretion by Hydrogen Sulfide

Nephrology, Dialysis, Transplantation : Official Publication of the European Dialysis and Transplant Association - European Renal Association. Jul, 2011  |  Pubmed ID: 21208996

Hydrogen sulfide (H(2)S) is considered as the third gasotransmitter after nitric oxide and carbon monoxide. This gas molecule participates in the regulation of renal function. Diabetic nephropathy (DN) is one of the major chronic complications of diabetes. The present study aimed to explore the changes in H(2)S metabolism in the early stage of DN and the effects of H(2)S on cultured rat renal glomerular mesangial cells (MCs).

Inhibition of Urinary Bladder Carcinogenesis by Aqueous Extract of Sclerotia of Polyporus Umbellatus Fries and Polyporus Polysaccharide

The American Journal of Chinese Medicine. 2011  |  Pubmed ID: 21213404

The study aimed to evaluate inhibition effect of sclerotia of Polyporus umbellatus Fries aqueous extract (SPUE) and polyporus polysaccharide (PPS) on bladder cancer, then to measure their effect on mRNA expression of glutathione S-transferase π (GSTPi) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in female Fischer-344 rats model. The model rats were induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) for a period of 8 weeks and saccharin for 12 weeks. SPUE (50 mg/kg, 250 mg/kg, 500 mg/kg) and PPS (28 mg/kg) were orally administrated to the model rats during the whole study. Compared to the control group, a more preventive effect of SPUE and PPS treatment on bladder cancer was discovered, higher mRNA upregulation of GSTpi and NQO1 was seen in the treatment group. Furthermore, the GSTPi and NQO1 mRNA upregulated level in the low-dose group (SPUE 50 mg/kg) was at maximum. In brief, SPUE and PPS are highly effective in inhibiting bladder carcinogenesis in rats, which may be associated with upregulation of GSTPi and NQO1 in the bladder.

Influence of Growing Season on Phenolic Compounds and Antioxidant Properties of Grape Berries from Vines Grown in Subtropical Climate

Journal of Agricultural and Food Chemistry. Feb, 2011  |  Pubmed ID: 21235208

The influence of growing season (winter vs summer) on the synthesis and accumulation of phenolic compounds and antioxidant properties was studied in five grape cultivars for three consecutive years. Four phenolic compound parameters (total phenols, flavonoids, flavan-3-ols, and anthocyanins) and three antioxidant property parameters [2,2-diphenyl-1-picrylhydrazyl radical scavenging, 2,2-azinobis(3-ethylbenzothiazolinesulfonic acid) radical scavenging, and ferric reducing antioxidant power] were investigated. Results showed that both phenolic compounds and antioxidant properties in the seed and skin of winter berries were significantly (p < 0.05) higher than those of summer berries for all of the cultivars investigated. The anthocyanin profiles of berry skins appeared to be extremely consistent in different years for the same crop, whereas they varied greatly between the two crops within the same year (winter vs summer). Winter berries contained richer glucosides of delphinidin, cyanidin, peonidin, and malvidin than summer berries. These seasonal variations of phenolic compounds and antioxidant properties on grape berries were largely contributed by climatic factors such as temperature, solar radiation, rainfall, and hydrothermic coefficient between different growing seasons.

Composition Tuning the Upconversion Emission in NaYF4:Yb/Tm Hexaplate Nanocrystals

Nanoscale. Mar, 2011  |  Pubmed ID: 21264435

Single crystal hexagonal NaYF4:Yb/Tm nanocrystals have been synthesized with uniform size, morphology and controlled chemical composition. Spectroscopic studies show that these nanocrystals exhibit strong energy upconversion emission when excited with a 980 nm diode laser, with two primary emission peaks centered around 452 nm and 476 nm. Importantly, the overall and relative emission intensity at these wavelengths can be readily tuned by controlling the concentration of the trivalent rare earth element dopants at the beginning of the synthesis which has been confirmed by EDX for the first time. Through systematic studies, the optimum rare earth ion doping concentration can be determined for the strongest emission intensity at the selected peak(s). Confocal microscopy studies show that the upconversion emission from individual NCs can be readily visualized. These studies demonstrate a rational approach for fine tuning the upconversion properties in rare-earth doped nanostructures and can broadly impact areas ranging from energy harvesting, energy conversion to biomedical imaging and therapeutics.

[Correlation Between T Lymphocyte Subsets and Different Syndrome Types in Patients with Influenza A (H1N1): a Retrospective Study]

Zhong Xi Yi Jie He Xue Bao = Journal of Chinese Integrative Medicine. Feb, 2011  |  Pubmed ID: 21288448

To investigate the changes in T lymphocyte subsets in patients with different syndrome types infected by influenza A (H1N1) virus after treatment.

Enhanced Excitability and Down-regulated Voltage-gated Potassium Channels in Colonic Drg Neurons from Neonatal Maternal Separation Rats

The Journal of Pain : Official Journal of the American Pain Society. May, 2011  |  Pubmed ID: 21296029

Irritable bowel syndrome (IBS), characterized mainly by abdominal pain, is a functional bowel disorder. The present study aimed to examine changes in the excitability and the activity of the voltage-gated K(+) channel in dorsal root ganglia (DRG) neurons innervating the colon of rats subjected to neonatal maternal separation (NMS). Colonic DRG neurons from NMS rats as identified by FAST DiI™ labeling showed an increased cell size compared with those from nonhandled (NH) rats. Whole cell current-clamp recordings showed that colonic DRG neurons from NMS rats displayed: 1) depolarized resting membrane potential; 2) increased input resistance; 3) a dramatic reduction in rheobase; and 4) a significant increase in the number of action potentials evoked at twice rheobase. Whole cell voltage-clamp recordings revealed that neurons from both groups exhibited transient A-type (I(A)) and delayed rectifier (I(K)) K(+) currents. Compared with NH rat neurons, the averaged density of I(K) was significantly reduced in NMS rat neurons. Furthermore, the Kv1.2 expression was significantly decreased in NMS rat colonic DRG neurons. These results suggest that NMS increases the excitability of colonic DRG neurons mainly by suppressing the I(K) current, which is likely accounted for by the downregulation of the Kv1.2 expression and somal hypertrophy. PERSPECTIVE: This study demonstrates the alteration of delayed rectifier K current and Kv1.2 expression in DRG neurons from IBS model rats, representing a molecular mechanism underlying visceral pain and sensitization in IBS, suggesting the potential of Kv1.2 as a therapeutic target for the treatment of IBS.

Highly Spectral Dependent Enhancement of Upconversion Emission with Sputtered Gold Island Films

Chemical Communications (Cambridge, England). Jan, 2011  |  Pubmed ID: 21079884

We report a five-fold overall enhancement of upconversion emission in NaYF(4) : Yb/Er nanocrystals when coupled with gold island films. Spectroscopic studies show that the enhancement factors are highly dependent on the exact spectral positions and excitation power density, with a largest enhancement factor of more than 12 observed at selected spectral positions, which may be attributed to different upconversion processes involved.

B-MYB Delays Cell Aging by Repressing P16 (INK4α) Transcription

Cellular and Molecular Life Sciences : CMLS. Mar, 2011  |  Pubmed ID: 20734103

p16 ( INK4α ), an inhibitor of cyclin-dependent kinase 4 and 6, has been proposed to play an important role in cellular aging and in premature senescence. The expression of the p16 ( INK4α ) is primarily under transcriptional control. Our previous data showed that a negative regulation element lies in its promoter. In that element, a MYB-binding site (MBS) was uncovered by transcription analysis. Here, we report that MBS is a negative regulation element and B-MYB binds to this site in vivo. In human embryonic lung fibroblast cells, B-MYB downregulated p16 ( INK4α ) expression, whereas knocking down of B-MYB upregulated it. Evidence also showed that overexpression of B-MYB in cells could increase the number of utmost passage and decrease G1 block, whereas knocking down of B-MYB could impair their replicative ability. This study provides evidence of the capacity of B-MYB not only to regulate p16 ( INK4α ) expression but also the phenotypic consequence on cellular senescence.

Extracellular Spermine Exacerbates Ischemic Neuronal Injury Through Sensitization of ASIC1a Channels to Extracellular Acidosis

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience. Feb, 2011  |  Pubmed ID: 21307247

Ischemic brain injury is a major problem associated with stroke. It has been increasingly recognized that acid-sensing ion channels (ASICs) contribute significantly to ischemic neuronal damage, but the underlying mechanism has remained elusive. Here, we show that extracellular spermine, one of the endogenous polyamines, exacerbates ischemic neuronal injury through sensitization of ASIC1a channels to extracellular acidosis. Pharmacological blockade of ASIC1a or deletion of the ASIC1 gene greatly reduces the enhancing effect of spermine in ischemic neuronal damage both in cultures of dissociated neurons and in a mouse model of focal ischemia. Mechanistically, spermine profoundly reduces desensitization of ASIC1a by slowing down desensitization in the open state, shifting steady-state desensitization to more acidic pH, and accelerating recovery between repeated periods of acid stimulation. Spermine-mediated potentiation of ASIC1a activity is occluded by PcTX1 (psalmotoxin 1), a specific ASIC1a inhibitor binding to its extracellular domain. Functionally, the enhanced channel activity is accompanied by increased acid-induced neuronal membrane depolarization and cytoplasmic Ca(2+) overload, which may partially explain the exacerbated neuronal damage caused by spermine. More importantly, blocking endogenous spermine synthesis significantly attenuates ischemic brain injury mediated by ASIC1a but not that by NMDA receptors. Thus, extracellular spermine contributes significantly to ischemic neuronal injury through enhancing ASIC1a activity. Our data suggest new neuroprotective strategies for stroke patients via inhibition of polyamine synthesis and subsequent spermine-ASIC interaction.

Pivotal Role of Protein Kinase Cdelta in Angiotensin II-induced Endothelial Cyclooxygenase-2 Expression: a Link to Vascular Inflammation

Arteriosclerosis, Thrombosis, and Vascular Biology. May, 2011  |  Pubmed ID: 21311042

The purpose of this study was to examine the hypothesis that angiotensin II (Ang II) induced endothelial cyclooxygenase-2 (COX-2) expression, which in turn mediated the generation of proinflammatory cytokines.

Type 1 Receptor Parathyroid Hormone (PTH1R) Influences Breast Cancer Cell Proliferation and Apoptosis Induced by High Levels of Glucose

Medical Oncology (Northwood, London, England). Feb, 2011  |  Pubmed ID: 21312071

Increased breast cancer incidence parallels the increase in cases of type 2 diabetes. We investigated the effect of type 1 receptor parathyroid hormone (PTH1R) expression on viability and apoptosis of breast cancer cells exposed to high levels of glucose. Upregulation of PTH1R was detected in patients with invasive ductal carcinoma of the breast and diabetes. In vitro, PTH1R silencing suppressed cell proliferation and apoptosis induced by high levels of glucose by regulating Bax/Bcl-2 expression. These results suggest PTH1R silencing may represent a novel treatment approach for patients diagnosed with invasive ductal carcinoma of the breast who are also managing diabetes.

Effects of Copper on Phenology and Reproduction in Rumex Dentatus from Metalliferous and Non-metalliferous Sites

Ecotoxicology and Environmental Safety. May, 2011  |  Pubmed ID: 21316763

The responses of phenology and reproductive traits to copper stress in two populations of Rumex dentatus were comparatively studied with pot culture experiments. Seeds used for the experiments were, respectively, collected from metalliferous and normal soils. It was found that the responses of phenology and reproductive traits to Cu treatment between the two populations were significantly different. Compared to the non-metallicolous population, the metallicolous population of R. dentatus had a short life cycle, large reproductive effort, and high fertility under Cu stress. In addition, the reproductive effort in metallicolous population of R. dentatus was maintained at the expense of a curtailment of vegetative development. The results suggested that change in phenological traits and more resources allocation to reproduction might play an important role in the adaptation of metallicolous population of R. dentatus to the Cu-enriched mine soils.

Apple Polyphenols Extend the Mean Lifespan of Drosophila Melanogaster

Journal of Agricultural and Food Chemistry. Mar, 2011  |  Pubmed ID: 21319854

Apple polyphenols (AP) are an excellent source of dietary antioxidants. The present study investigated the effect of AP on the lifespan of fruit flies and their interaction with gene expressions of superoxide dismutase (SOD), catalase (CAT), methuselah (MTH), Rpn11, and cytochrome c oxidase (CcO) subunits III and VIb. Results showed the mean lifespan was significantly extended by 10% in fruit flies fed the AP diet. This was accompanied by up-regulation of genes SOD1, SOD2, and CAT and down-regulation of MTH in the aged fruit flies. Paraquat and H(2)O(2) challenge tests demonstrated that AP prolonged the survival time only for Oregon R wild type flies but not for SOD(n108) or Cat(n1) mutants, in which either SOD or CAT was knocked out. Chronic paraquat exposure could shorten the maximum lifespan from 68 to 31 days and reduce the climbing ability by 60%, whereas AP could partially reverse the paraquat-induced mortality and decline in climbing ability. AP could up-regulate Rpn11 at day 30, whereas it appeared to have no significant effect on gene expression of ubiquitinated protein, CcO subunits III and VIb. These AP-induced changes were unlikely associated with caloric restriction as the gustatory assay found no difference in average body weight and stomach redness index between the control and AP fruit flies. It was therefore concluded that the antiaging activity of AP was, at least in part, mediated by its interaction with genes SOD, CAT, MTH, and Rpn11.

Edge Effect on Resistance Scaling Rules in Graphene Nanostructures

Nano Letters. Mar, 2011  |  Pubmed ID: 21322591

We report an experimental investigation of the edge effect on the room-temperature transport in graphene nanoribbon and graphene sheet (both single-layer and bilayer). By measuring the resistance scaling behaviors at both low- and high-carrier densities, we show that the transport of single-layer nanoribbons lies in a strong localization regime, which can be attributed to an edge effect. We find that this edge effect can be weakened by enlarging the width, decreasing the carrier densities, or adding an extra layer. From graphene nanoribbon to graphene sheet, the data show a dimensional crossover of the transport regimes possibly due to the drastic change of the edge effect.

Endothelium-mediated Control of Vascular Tone: COX-1 and COX-2 Products

British Journal of Pharmacology. Oct, 2011  |  Pubmed ID: 21323907

Endothelium-dependent contractions contribute to endothelial dysfunction in various animal models of aging, diabetes and cardiovascular diseases. In the spontaneously hypertensive rat, the archetypal model for endothelium-dependent contractions, the production of the endothelium-derived contractile factors (EDCF) involves an increase in endothelial intracellular calcium concentration, the production of reactive oxygen species, the predominant activation of cyclooxygenase-1 (COX-1) and to a lesser extent that of COX-2, the diffusion of EDCF towards the smooth muscle cells and the subsequent stimulation of their thromboxane A2-endoperoxide TP receptors. Endothelium-dependent contractions are also observed in various models of hypertension, aging and diabetes. They generally also involve the generation of COX-1- and/or COX-2-derived products and the activation of smooth muscle TP receptors. Depending on the model, thromboxane A(2), PGH(2), PGF(2α), PGE(2) and paradoxically PGI(2) can all act as EDCFs. In human, the production of COX-derived EDCF is a characteristic of the aging and diseased blood vessels, with essential hypertension causing an earlier onset and an acceleration of this endothelial dysfunction. As it has been observed in animal models, COX-1, COX-2 or both isoforms can contribute to these endothelial dysfunctions. Since in most cases, the activation of TP receptors is the common downstream effector, selective antagonists of this receptor should curtail endothelial dysfunction and be of therapeutic interest in the treatment of cardiovascular disorders.

Oxidized LDL at Low Concentration Promotes In-vitro Angiogenesis and Activates Nitric Oxide Synthase Through PI3K/Akt/eNOS Pathway in Human Coronary Artery Endothelial Cells

Biochemical and Biophysical Research Communications. Apr, 2011  |  Pubmed ID: 21352809

It has long been considered that oxidized low-density lipoprotein (oxLDL) causes endothelial dysfunction and is remarkably related to the development of atherosclerosis. However, the effect of oxLDL at very low concentration (<10μg/ml) on the endothelial cells remains speculative. Nitric oxide (NO) has a crucial role in the endothelial cell function. In this study, we investigated the effect of oxLDL at low concentration on NO production and proliferation, migration, tube formation of the human coronary artery endothelial cells (HCAEC). Results showed that oxLDL at 5μg/ml enhanced HCAEC proliferation, migration and tube formation. These phenomena were accompanied by an increased intracellular NO production. l-NAME (a NOS inhibitor), LY294002 and wortmannin (PI3K inhibitors) could abolish oxLDL-induced angiogenic effects and prevent NO production in the HCAEC. The phosphorylation of Akt, PI3K and eNOS were up-regulated by oxLDL, which was attenuated by LY294002. Our results suggested that oxLDL at low concentration could promote in-vitro angiogenesis and activate nitric oxide synthesis through PI3K/Akt/eNOS pathway in HCAEC.

[Application of High-frequency Electrocautery Combined with High Pressure Balloon Expansion in Treatment of Benign Airway Obstruction]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Feb, 2011  |  Pubmed ID: 21354933

To study the value of high-frequency electrocautery combined with high-pressure balloon expansion in the treatment of benign airway obstruction.

Hard Arteries, Weak Bones

Skeletal Radiology. May, 2011  |  Pubmed ID: 21359689

Semiconductor Nanomembrane Tubes: Three-dimensional Confinement for Controlled Neurite Outgrowth

ACS Nano. Apr, 2011  |  Pubmed ID: 21366271

In many neural culture studies, neurite migration on a flat, open surface does not reflect the three-dimensional (3D) microenvironment in vivo. With that in mind, we fabricated arrays of semiconductor tubes using strained silicon (Si) and germanium (Ge) nanomembranes and employed them as a cell culture substrate for primary cortical neurons. Our experiments show that the SiGe substrate and the tube fabrication process are biologically viable for neuron cells. We also observe that neurons are attracted by the tube topography, even in the absence of adhesion factors, and can be guided to pass through the tubes during outgrowth. Coupled with selective seeding of individual neurons close to the tube opening, growth within a tube can be limited to a single axon. Furthermore, the tube feature resembles the natural myelin, both physically and electrically, and it is possible to control the tube diameter to be close to that of an axon, providing a confined 3D contact with the axon membrane and potentially insulating it from the extracellular solution.

Polarization Modulation Thermal Lens Microscopy for Imaging the Orientation of Non-spherical Nanoparticles

Optics Express. Jan, 2011  |  Pubmed ID: 21369085

In this paper a far field optical technique we call polarization modulation thermal lens microscopy (PM-TLM) is used for imaging the orientation and dichroism of non-spherical nanoparticles. In PM-TLM, the polarization state of a pump beam is periodically modulated which in turn causes morphology related intensity fluctuations in a continuous probe beam, thus allowing high signal to noise ratio detection with using lock-in amplification. Since PM-TLM uses nanoparticle absorption as the contrast mechanism, it may be used to detect and image nanoparticles of far smaller dimensions than can be observed by conventional dark field optical microscopy. The technique, its implementation and experiment results are presented.

A Novel Anti-fibrotic Agent, Baicalein, for the Treatment of Myocardial Fibrosis in Spontaneously Hypertensive Rats

European Journal of Pharmacology. May, 2011  |  Pubmed ID: 21371455

Myocardial interstitial fibrosis causes left ventricular stiffness and diastolic dysfunction. Despite its clinical significance, treatment options are limited. The flavonoid baicalein, extracted from roots of a Chinese medicinal plant, Scutellaria baicalensis Georgi was shown to inhibit liver fibrosis. This study sought to investigate whether chronic treatment with baicalein could attenuate myocardial fibrosis in spontaneously hypertensive rats (SHR). SHR were treated daily with baicalein while the control group received vehicle. At the end of study, SHR control group developed significant myocardial fibrosis that was attenuated by baicalein treatment for 4 and 12 weeks. Rats treated with baicalein were protected against an increase in heart to body weight ratio, plasma level of brain natriuretic peptides, intraventricular septum thickness, myocardial collagen volume of left ventricle (all P<0.05, respectively). The antifibrotic effects of baicalein were further illustrated by the suppressed expression of left ventricle pro-collagens I and III accompanied by the decreased expression of 12-lipoxygenase, and by reduced expression and activity of matrix metallopeptidase 9 and extracellular signal-regulated kinases. The present results show for the first time that baicalein can inhibit cardiac fibrosis in hypertensive rats.

MiR-24 Inhibits Apoptosis and Represses Bim in Mouse Cardiomyocytes

The Journal of Experimental Medicine. Mar, 2011  |  Pubmed ID: 21383058

Acute myocardial infarction (MI) involves necrotic and apoptotic loss of cardiomyocytes. One strategy to salvage ischemic cardiomyocytes is to modulate gene expression to promote cell survival without disturbing normal cardiac function. MicroRNAs (miRNAs) have emerged as powerful regulators of multiple cellular processes, including apoptosis, suggesting that regulation of miRNA function could serve a cardioprotective function. In this study, we report that miR-24 (miRNA-24) expression is down-regulated in the ischemic border zone of the murine left ventricle after MI. miR-24 suppresses cardiomyocyte apoptosis, in part by direct repression of the BH3-only domain-containing protein Bim, which positively regulates apoptosis. In vivo expression of miR-24 in a mouse MI model inhibited cardiomyocyte apoptosis, attenuated infarct size, and reduced cardiac dysfunction. This antiapoptotic effect on cardiomyocytes in vivo was partially mediated by Bim. Our results suggest that manipulating miRNA levels during stress-induced apoptosis may be a novel therapeutic strategy for cardiac disease.

AVE3085, an Enhancer of Endothelial Nitric Oxide Synthase, Restores Endothelial Function and Reduces Blood Pressure in Spontaneously Hypertensive Rats

British Journal of Pharmacology. Jul, 2011  |  Pubmed ID: 21385179

Nitric oxide (NO) plays an important role in endothelial function, and impaired NO production is involved in hypertension. Therefore, compounds that regulate endothelial NO synthase (eNOS) may be of therapeutic benefit. A novel, low molecular weight compound AVE3085 is a recently developed compound with the ability to enhance eNOS transcription. The present study investigated the effects of AVE3085 in endothelial dysfunction associated with hypertension.

Targeting Soluble Epoxide Hydrolase Via Peroxisome Proliferator-activated Receptor γ: a New Therapeutic Strategy for Vascular Complications

Clinical and Experimental Pharmacology & Physiology. Jun, 2011  |  Pubmed ID: 21388433

[The Fused Tooth of Maxillary Third Molar with Supernumerary Tooth: a Case Report]

Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi Kouqiang Yixue Zazhi = West China Journal of Stomatology. Feb, 2011  |  Pubmed ID: 21427912

The fused tooth is the union of two dental enamel or dentin formed together. In the maxillary, the fusion usually occurred within the lateral incisor and canine and very rarely occurred in the upper third molar and supernumerary tooth. This paper reported a fused tooth occurred in the left maxillary impacted third molar with supernumerary tooth.

[High-precision Measurement of Spherical Mirror Reflectivity in Vacuum Ultraviolet Spectrum]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Jan, 2011  |  Pubmed ID: 21428105

In order to directly measure the vacuum ultraviolet spectrum reflectance of spherical mirror a measurement system was established. The system consists of monochromatic light source with deuterium lamp of magnesium fluoride window and Seya-Namioka concave grating monochromator, optical compensator with reflection modulator and reference detector and the receiving system with 80 mm diameter fluorescence integrating sphere and precision turntable. The optical compensation eliminates the instability in monochromatic light source, and the fluorescence integrating sphere eliminates the impact of light spot sizes in the two measurements, and reduce the system energy loss. The system measures the spherical mirror reflectivity in 115-180 nm, and the measurement result show that the repeatability is less than +/- 0.3%, and the relative uncertainty is less than 1.3%. The spherical mirror reflectivity achieves high-precision measurement.

Inhibition of Renin-angiotensin System Reverses Endothelial Dysfunction and Oxidative Stress in Estrogen Deficient Rats

PloS One. 2011  |  Pubmed ID: 21479266

Estrogen deficiency increases the cardiovascular risks in postmenopausal women. Inhibition of the renin-angiotensin system (RAS) and associated oxidative stress confers a cardiovascular protection, but the role of RAS in estrogen deficiency-related vascular dysfunction is unclear. The present study investigates whether the up-regulation of RAS and associated oxidative stress contributes to the development of endothelial dysfunction during estrogen deficiency in ovariectomized (OVX) rats.

CAMP Activates TRPC6 Channels Via the Phosphatidylinositol 3-kinase (PI3K)-protein Kinase B (PKB)-mitogen-activated Protein Kinase Kinase (MEK)-ERK1/2 Signaling Pathway

The Journal of Biological Chemistry. Jun, 2011  |  Pubmed ID: 21487005

cAMP is an important second messenger that executes diverse physiological function in living cells. In this study, we investigated the effect of cAMP on canonical TRPC6 (transient receptor potential channel 6) channels in TRPC6-expressing HEK293 cells and glomerular mesangial cells. The results showed that 500 μm 8-Br-cAMP, a cell-permeable analog of cAMP, elicited [Ca(2+)](i) increases and stimulated a cation current at the whole-cell level in TRPC6-expressing HEK293 cells. The effect of cAMP diminished in the presence of the PI3K inhibitors wortmannin and LY294002 or the MEK inhibitors PD98059, U0126, and MEK inhibitor I. 8-Br-cAMP also induced phosphorylation of MEK and ERK1/2. Conversion of serine to glycine at an ERK1/2 phosphorylation site (S281G) abolished the cAMP activation of TRPC6 as determined by whole-cell and cell-attached single-channel patch recordings. Experiments based on a panel of pharmacological inhibitors or activators suggested that the cAMP action on TRPC6 was not mediated by PKA, PKG, or EPAC (exchange protein activated by cAMP). Total internal fluorescence reflection microscopy showed that 8-Br-cAMP did not alter the trafficking of TRPC6 to the plasma membrane. We also found that, in glomerular mesangial cells, glucagon-induced [Ca(2+)](i) increases were mediated through the cAMP-PI3K-PKB-MEK-ERK1/2-TRPC6 signaling pathway. In summary, this study uncovered a novel TRPC6 activation mechanism in which cAMP activates TRPC6 via the PI3K-PKB-MEK-ERK1/2 signaling pathway.

Elevated Soluble CD40 Ligand in Diabetic Patients with Painless Myocardial Infarction

BioFactors (Oxford, England). Mar, 2011  |  Pubmed ID: 21488132

Because a useful biomarker for painless myocardial infarction (MI) has yet to be identified, the aim of this study was to identify a biomarker for diabetic patients with painless MI. A case-control design was used to compare inflammatory cytokine levels among 111 patients with diabetes mellitus, including 31 patients with stable coronary heart disease (CHD), 30 patients with painful MI, 20 patients with painless MI, and 30 age- and sex-matched patients without CHD (control group). In addition to baseline parameters, cytokine levels, including plasma high sensitivity C-reactive protein (HsCRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and soluble CD40 ligand (sCD40L) levels, were analyzed using enzyme-linked immunosorbent assays (ELISAs). No differences in baseline characteristics were observed for patients with painless MI as compared to the other patient groups. Significantly higher sCD40L, HsCRP, IL-6, and TNF-α levels were detected in patients with MI, and markedly elevated sCD40L and IL-6 levels were observed in patients with painless MI as compared to those with painful MI. sCD40L may be a useful biomarker for painless MI in diabetic patients, which could reduce misdiagnosis and expedite treatment. Further studies are required to validate the diagnostic utility of this putative biomarker as well as investigate the mechanism by which sCD40L is elevated in these patients.

A Genome-wide Screen Reveals a Role for MicroRNA-1 in Modulating Cardiac Cell Polarity

Developmental Cell. Apr, 2011  |  Pubmed ID: 21497762

Many molecular pathways involved in heart disease have their roots in evolutionarily ancient developmental programs that depend critically on gene dosage and timing. MicroRNAs (miRNAs) modulate gene dosage posttranscriptionally, and among these, the muscle-specific miR-1 is particularly important for developing and maintaining somatic/skeletal and cardiac muscle. To identify pathways regulated by miR-1, we performed a forward genetic screen in Drosophila using wing-vein patterning as a biological assay. We identified several unexpected genes that genetically interacted with dmiR-1, one of which was kayak, encodes a developmentally regulated transcription factor. Additional studies directed at this genetic relationship revealed a previously unappreciated function of dmiR-1 in regulating the polarity of cardiac progenitor cells. The mammalian ortholog of kayak, c-Fos, was dysregulated in hearts of gain- or loss-of-function miR-1 mutant mice in a stress-dependent manner. These findings illustrate the power of Drosophila-based screens to find points of intersection between miRNAs and conserved pathways in mammals.

Platinum Nanocrystals Selectively Shaped Using Facet-specific Peptide Sequences

Nature Chemistry. May, 2011  |  Pubmed ID: 21505499

The properties of a nanocrystal are heavily influenced by its shape. Shape control of a colloidal nanocrystal is believed to be a kinetic process, with high-energy facets growing faster then vanishing, leading to nanocrystals enclosed by low-energy facets. Identifying a surfactant that can specifically bind to a particular crystal facet is critical, but has proved challenging to date. Biomolecules have exquisite specific molecular recognition properties that can be explored for the precise engineering of nanostructured materials. Here, we report the use of facet-specific peptide sequences as regulating agents for the predictable synthesis of platinum nanocrystals with selectively exposed crystal surfaces and particular shapes. The formation of platinum nanocubes and nanotetrahedrons are demonstrated with Pt-{100} and Pt-{111} binding peptides, respectively. Our studies unambiguously demonstrate the abilities of facet-selective binding peptides in determining nanocrystal shape, representing a critical step forward in the use of biomolecules for programmable synthesis of nanostructures.

Microfluidics-based Devices: New Tools for Studying Cancer and Cancer Stem Cell Migration

Biomicrofluidics. 2011  |  Pubmed ID: 21522502

Cell movement is highly sensitive to stimuli from the extracellular matrix and media. Receptors on the plasma membrane in cells can activate signal transduction pathways that change the mechanical behavior of a cell by reorganizing motion-related organelles. Cancer cells change their migration mechanisms in response to different environments more robustly than noncancer cells. Therefore, therapeutic approaches to immobilize cancer cells via inhibition of the related signal transduction pathways rely on a better understanding of cell migration mechanisms. In recent years, engineers have been working with biologists to apply microfluidics technology to study cell migration. As opposed to conventional cultures on dishes, microfluidics deals with the manipulation of fluids that are geometrically constrained to a submillimeter scale. Such small scales offer a number of advantages including cost effectiveness, low consumption of reagents, high sensitivity, high spatiotemporal resolution, and laminar flow. Therefore, microfluidics has a potential as a new platform to study cell migration. In this review, we summarized recent progress on the application of microfluidics in cancer and other cell migration researches. These studies have enhanced our understanding of cell migration and cancer invasion as well as their responses to subtle variations in their microenvironment. We hope that this review will serve as an interdisciplinary guidance for both biologists and engineers as they further develop the microfluidic toolbox toward applications in cancer research.

Chemokine Axes CXCL12/CXCR4 and CXCL16/CXCR6 Correlate with Lymph Node Metastasis in Epithelial Ovarian Carcinoma

Chinese Journal of Cancer. May, 2011  |  Pubmed ID: 21527066

Recent evidence suggests that the chemokine axis of CXC chemokine ligand-12 and its receptor CXC chemokine receptor-4 (CXCL12/CXCR4) is highly expressed in gynecological tumors and the axis of CXC chemokine ligand-16 and CXC chemokine receptor-6 (CXCL16/CXCR6) is overexpressed in inflammation-associated tumors. This study aimed to determine the relationship between CXCL12/CXCR4, CXCL16/CXCR6 and ovarian carcinoma's clinicopathologic features and prognosis. Accordingly, the expression of these proteins in ovarian tissues was detected by tissue microarray and immunohistochemistry. The expressions of CXCL12/CXCR4 and CXCL16/CXCR6 were significantly higher in epithelial ovarian carcinomas than in normal epithelial ovarian tissues or benign epithelial ovarian tumors. The expression of chemokines CXCL12 and CXCL16 were positively correlated with their receptors CXCR4 and CXCR6 in ovarian carcinoma, respectively (r = 0.300, P < 0.05; r = 0.395, P < 0.05). Moreover, the expression of CXCL12 was related to the occurrence of ascites (Χ² = 4.76, P < 0.05), the expression of CXCR4 was significantly related to lymph node metastasis (Χ(2) = 4.37, P < 0.05), the expression of CXCR6 was significantly related to lymph node metastasis (Χ² = 7.43, P < 0.05) and histological type (Χ² = 33.48, P < 0.05). In univariate analysis, the expression of CXCR4 and CXCL16 significantly correlated with reduced median survival (Χ² = 4.67, P < 0.05; Χ² = 4.48, P < 0.05). Therefore, we conclude that the chemokine axes CXCL12/CXCR4 and CXCL16/CXCR6 may play important roles in the growth, proliferation, invasion, and metastasis of epithelial ovarian carcinoma.

A Multistage Pathway for Human Prion Protein Aggregation in Vitro: from Multimeric Seeds to β-oligomers and Nonfibrillar Structures

Journal of the American Chemical Society. Jun, 2011  |  Pubmed ID: 21534611

Aberrant protein aggregation causes numerous neurological diseases including Creutzfeldt-Jakob disease (CJD), but the aggregation mechanisms remain poorly understood. Here, we report AFM results on the formation pathways of β-oligomers and nonfibrillar aggregates from wild-type full-length recombinant human prion protein (WT) and an insertion mutant (10OR) with five additional octapeptide repeats linked to familial CJD. Upon partial denaturing, seeds consisting of 3-4 monomers quickly appeared. Oligomers of ~11-22 monomers then formed through direct interaction of seeds, rather than by subsequent monomer attachment. All larger aggregates formed through association of these β-oligomers. Although both WT and 10OR exhibited identical aggregation mechanisms, the latter oligomerized faster due to lower solubility and, hence, thermodynamic stability. This novel aggregation pathway has implications for prion diseases as well as others caused by protein aggregation.

Characterization of a Novel Positive Transcription Regulatory Element That Differentially Regulates the Alpha-2-macroglobulin Gene in Replicative Senescence

Biogerontology. Dec, 2011  |  Pubmed ID: 21541797

Alpha-2-macroglobulin (α2M), a protease inhibitor, is implicated in Alzheimer's disease, atherosclerosis, and other age-related diseases. The elevated level of α2M mRNA has been described in replicative senescence and it could be used as a biomarker of the aging cells. However, the mechanism responsible for the up-regulation of its expression is still unclear. This report identified a novel transcriptional regulatory element, the α2M transcription enhancement element (ATEE), within the α2M promoter. This element differentially activates α2M expression in senescent versus young fibroblasts. Electrophoretic mobility shift assays revealed abundant complexes in senescent cell nuclear extracts compared with young cell nuclear extracts. The DNase I footprint revealed the protein-binding core sequence through which the protein binds the ATEE. Mutation within ATEE selectively abolished α2M promoter activity in senescent (but not young) cells. These results indicated the ATEE, as a positive transcription regulatory element, contributes to the up-regulation of α2M during replicative senescence.

Top-gated Chemical Vapor Deposition Grown Graphene Transistors with Current Saturation

Nano Letters. Jun, 2011  |  Pubmed ID: 21548551

Graphene transistors are of considerable interest for radio frequency (rf) applications. In general, transistors with large transconductance and drain current saturation are desirable for rf performance, which is however nontrivial to achieve in graphene transistors. Here we report high-performance top-gated graphene transistors based on chemical vapor deposition (CVD) grown graphene with large transconductance and drain current saturation. The graphene transistors were fabricated with evaporated high dielectric constant material (HfO(2)) as the top-gate dielectrics. Length scaling studies of the transistors with channel length from 5.6 μm to 100 nm show that complete current saturation can be achieved in 5.6 μm devices and the saturation characteristics degrade as the channel length shrinks down to the 100-300 nm regime. The drain current saturation was primarily attributed to drain bias induced shift of the Dirac points. With the selective deposition of HfO(2) gate dielectrics, we have further demonstrated a simple scheme to realize a 300 nm channel length graphene transistors with self-aligned source-drain electrodes to achieve the highest transconductance of 250 μS/μm reported in CVD graphene to date.

Elevated MiR-499 Levels Blunt the Cardiac Stress Response

PloS One. 2011  |  Pubmed ID: 21573063

The heart responds to myriad stresses by well-described transcriptional responses that involve long-term changes in gene expression as well as more immediate, transient adaptations. MicroRNAs quantitatively regulate mRNAs and thus may affect the cardiac transcriptional output and cardiac function. Here we investigate miR-499, a microRNA embedded within a ventricular-specific myosin heavy chain gene, which is expressed in heart and skeletal muscle.

Analysis and Visualization of Arabidopsis Thaliana GWAS Using Web 2.0 Technologies

Database : the Journal of Biological Databases and Curation. 2011  |  Pubmed ID: 21609965

With large-scale genomic data becoming the norm in biological studies, the storing, integrating, viewing and searching of such data have become a major challenge. In this article, we describe the development of an Arabidopsis thaliana database that hosts the geographic information and genetic polymorphism data for over 6000 accessions and genome-wide association study (GWAS) results for 107 phenotypes representing the largest collection of Arabidopsis polymorphism data and GWAS results to date. Taking advantage of a series of the latest web 2.0 technologies, such as Ajax (Asynchronous JavaScript and XML), GWT (Google-Web-Toolkit), MVC (Model-View-Controller) web framework and Object Relationship Mapper, we have created a web-based application (web app) for the database, that offers an integrated and dynamic view of geographic information, genetic polymorphism and GWAS results. Essential search functionalities are incorporated into the web app to aid reverse genetics research. The database and its web app have proven to be a valuable resource to the Arabidopsis community. The whole framework serves as an example of how biological data, especially GWAS, can be presented and accessed through the web. In the end, we illustrate the potential to gain new insights through the web app by two examples, showcasing how it can be used to facilitate forward and reverse genetics research. Database URL: http://arabidopsis.usc.edu/

[Researches on Factors Affecting the Removal of Carbamazepine by Nanofiltration Membranes]

Huan Jing Ke Xue= Huanjing Kexue / [bian Ji, Zhongguo Ke Xue Yuan Huan Jing Ke Xue Wei Yuan Hui "Huan Jing Ke Xue" Bian Ji Wei Yuan Hui.]. Mar, 2011  |  Pubmed ID: 21634167

The influence factors on removal of carbamazepine (CBZ) in drinking water by nanofiltration membrane was mainly investigated. The effect of CBZ removal by NF270 and NF90 was firstly compared and found that removal efficiency by NF90 with small pore size showed more effectively than removed by NF270 with large pore size. The next experiment focused on the effect of various factors on removal with respect to CBZ initial concentration, pH, ionic strength and water temperature. The results showed that removal efficiency reduced with decreased pH and increased Ca2+ concentration and water temperature. The effect of initial concentration in the range of 50-500 microg/L on flux and CBZ removal was insignificant. It can be concluded that the retention of non-ionic CBZ by loose NF membrane was strongly dependent on the mechanism of steric (size) exclusion.

Scalable Fabrication of Self-Aligned Graphene Transistors and Circuits on Glass

Nano Letters. Jun, 2011  |  Pubmed ID: 21648419

Graphene transistors are of considerable interest for radio frequency (rf) applications. High-frequency graphene transistors with the intrinsic cutoff frequency up to 300 GHz have been demonstrated. However, the graphene transistors reported to date only exhibit a limited extrinsic cutoff frequency up to about 10 GHz, and functional graphene circuits demonstrated so far can merely operate in the tens of megahertz regime, far from the potential the graphene transistors could offer. Here we report a scalable approach to fabricate self-aligned graphene transistors with the extrinsic cutoff frequency exceeding 50 GHz and graphene circuits that can operate in the 1-10 GHz regime. The devices are fabricated on a glass substrate through a self-aligned process by using chemical vapor deposition (CVD) grown graphene and a dielectrophoretic assembled nanowire gate array. The self-aligned process allows the achievement of unprecedented performance in CVD graphene transistors with a highest transconductance of 0.36 mS/μm. The use of an insulating substrate minimizes the parasitic capacitance and has therefore enabled graphene transistors with a record-high extrinsic cutoff frequency (> 50 GHz) achieved to date. The excellent extrinsic cutoff frequency readily allows configuring the graphene transistors into frequency doubling or mixing circuits functioning in the 1-10 GHz regime, a significant advancement over previous reports (∼20 MHz). The studies open a pathway to scalable fabrication of high-speed graphene transistors and functional circuits and represent a significant step forward to graphene based radio frequency devices.

The Influence of Surface Oxide on the Growth of Metal/semiconductor Nanowires

Nano Letters. Jul, 2011  |  Pubmed ID: 21657260

We report the critical effects of oxide on the growth of nanostructures through silicide formation. Under an in situ ultrahigh vacuum transmission electron microscope, it is observed from the conversion of Si nanowires into the metallic PtSi grains epitaxially through controlled reactions between lithographically defined Pt pads and Si nanowires. With oxide, instead of contact area, single crystal PtSi grains start forming either near the center between two adjacent pads or from the ends of Si nanowires, resulting in the heterostructure formation of Si/PtSi/Si. Without oxide, transformation from Si into PtSi begins at the contact area between them, resulting in the heterostructure formation of PtSi/Si/PtSi. The nanowire heterostructures have an atomically sharp interface with epitaxial relationships of Si(20-2)//PtSi(10-1) and Si[111]//PtSi[111]. Additionally, it has been observed that the existence of oxide significantly affects not only the growth position but also the growth behavior and the growth rate by two orders of magnitude. Molecular dynamics simulations have been performed to support our experimental results and the proposed growth mechanisms. In addition to fundamental science, the significance of the study matters for future processing techniques in nanotechnology and related applications as well.

Synthesis of Platinum Single-twinned Right Bipyramid and {111}-bipyramid Through Targeted Control over Both Nucleation and Growth Using Specific Peptides

Nano Letters. Jul, 2011  |  Pubmed ID: 21667927

Shape-controlled synthesis requires rigorous kinetic control over both nucleation and growth. For platinum (Pt), to date it is still challenging to generate twinned seeds in nucleation in a controllable fashion. Here, we report that a specific Pt binding peptide BP7A is able to mediate and stabilize single-twinned seeds formation at the nucleation stage under mild conditions. Importantly, it targets the control over nucleation directly. Combining with control over growth, we further demonstrate the rational design and synthesis of single-twinned structures, right bipyramid and {111}-bipyramid, by incorporating targeted facet stabilization over {100} facet and {111} facet, respectively. To the best of our knowledge, this is the first report on the successful synthesis of single-twinned bipyramids for Pt nanocrystals (NCs) with high yields. The work here demonstrates the power of biomolecules in recognizing and mediating inorganic nanomaterials synthesis, guiding the formation of material structures that are otherwise unconventional, and hence presenting one step further toward predictable and programmable biomimetic synthesis.

Tinman/Nkx2-5 Acts Via MiR-1 and Upstream of Cdc42 to Regulate Heart Function Across Species

The Journal of Cell Biology. Jun, 2011  |  Pubmed ID: 21690310

Unraveling the gene regulatory networks that govern development and function of the mammalian heart is critical for the rational design of therapeutic interventions in human heart disease. Using the Drosophila heart as a platform for identifying novel gene interactions leading to heart disease, we found that the Rho-GTPase Cdc42 cooperates with the cardiac transcription factor Tinman/Nkx2-5. Compound Cdc42, tinman heterozygous mutant flies exhibited impaired cardiac output and altered myofibrillar architecture, and adult heart-specific interference with Cdc42 function is sufficient to cause these same defects. We also identified K(+) channels, encoded by dSUR and slowpoke, as potential effectors of the Cdc42-Tinman interaction. To determine whether a Cdc42-Nkx2-5 interaction is conserved in the mammalian heart, we examined compound heterozygous mutant mice and found conduction system and cardiac output defects. In exploring the mechanism of Nkx2-5 interaction with Cdc42, we demonstrated that mouse Cdc42 was a target of, and negatively regulated by miR-1, which itself was negatively regulated by Nkx2-5 in the mouse heart and by Tinman in the fly heart. We conclude that Cdc42 plays a conserved role in regulating heart function and is an indirect target of Tinman/Nkx2-5 via miR-1.

Effect of Phytosterols and Their Oxidation Products on Lipoprotein Profiles and Vascular Function in Hamster Fed a High Cholesterol Diet

Atherosclerosis. Nov, 2011  |  Pubmed ID: 21719014

Human diets contain phytosterols and their oxidation products. We investigated effect of β-sitosterol (Si), stigmasterol (St), β-sitosterol oxidation products (SiOP) and stigmasterol oxidation products (StOP) on plasma total cholesterol and their interaction with the gene expression of enzymes, proteins and transporters involved in cholesterol absorption and metabolism. Sixty male hamsters were fed the control diet or one of four experimental diets containing 0.1% Si, 0.1% SiOP, 0.1% St and 0.1% StOP, respectively, for six weeks. SiOP and StOP groups had the relative liver weights greater than their corresponding non-oxidized forms, indicating they were possibly toxic. Results showed both Si and St groups reduced while SiOP and StOP hamsters lost the capacity of lowering plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL) and triacylglycerols (TG) compared with the control group. Si and St but not SiOP and StOP were anti-atherosclerotic. RT-PCR analysis demonstrated Si and St but not SiOP and StOP down-regulated mRNA levels of intestinal acyl CoA: cholesterol acyltransferase (ACAT2) and microsomal triglyceride protein (MTP). Aortas from Si and St hamsters relaxed better than those from the control and their corresponding SiOP and StOP-treated hamsters. It was concluded that Si and St not SiOP and StOP were beneficial in improving lipoprotein profile and aortic function.

Adiponectin is Required for PPARγ-mediated Improvement of Endothelial Function in Diabetic Mice

Cell Metabolism. Jul, 2011  |  Pubmed ID: 21723508

Rosiglitazone is a PPARγ agonist commonly used to treat diabetes. In addition to improving insulin sensitivity, rosiglitazone restores normal vascular function by a mechanism that remains poorly understood. Here we show that adiponectin is required to mediate the PPARγ effect on vascular endothelium of diabetic mice. In db/db and diet-induced obese mice, PPARγ activation by rosiglitazone restores endothelium-dependent relaxation of aortae, whereas diabetic mice lacking adiponectin or treated with an anti-adiponectin antibody do not respond. Rosiglitazone stimulates adiponectin release from fat explants, and subcutaneous fat transplantation from rosiglitazone-treated mice recapitulates vasodilatation in untreated db/db recipients. Mechanistically, adiponectin activates AMPK/eNOS and cAMP/PKA signaling pathways in aortae, which increase NO bioavailability and reduce oxidative stress. Taken together, these results demonstrate that adipocyte-derived adiponectin is required for PPARγ-mediated improvement of endothelial function in diabetes. Thus, the adipose tissue represents a promising target for treating diabetic vasculopathy.

The Regulatory Effects of Polyporus Polysaccharide on the Nuclear Factor Kappa B Signal Pathway of Bladder Cancer Cells Stimulated by Bacillus Calmette-Guerin

Chinese Journal of Integrative Medicine. Jul, 2011  |  Pubmed ID: 21725879

To detect the effects of Polyporus polysaccharide (PPS), Bacillus Calmette-Guerin (BCG), and their combination on the nuclear factor kappa B (NF-κB) signaling pathway associated-gene expression and investigate the molecular mechanisms of the toxic-reducing effect of PPS in coordination with BCG against bladder cancer.

[Expression of Special AT-rich Sequence-binding Protein 1 MRNA in Hepatocellular Carcinoma and Its Clinical Significance]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Jun, 2011  |  Pubmed ID: 21764697

To investigate the expression of special AT-rich sequence binding protein 1 (SATB1) mRNA in hepatocellular carcinoma (HCC) and explore its correlation to the clinicopathological features, surgical outcomes and metastasis of HCC.

Genetic Diversity and Genotype Analysis of Duck Circovirus

Avian Diseases. Jun, 2011  |  Pubmed ID: 21793450

To investigate the genetic diversity and genotype of duck circovirus (DuCV), nine full-length DuCV genomes were determined from clinical samples. Multiple sequence alignment and phylogenetic analyses were performed on the nine viral genome sequences as well as on 27 genome sequences retrieved from the GenBank database. Pairwise analysis showed that the determined genome sequences have a genome organization identical to the 27 sequences and share 83.3%-99.8% identity among themselves and 82.6%-99.9% with the other 27 sequences. Phylogenetic analysis revealed that all 36 viral genome sequences are divided into two lineages, DuCV1 and DuCV2, in which the nucleotide diversity between genome sequences in these two lineages ranged from 13.2%-17.4%; these may be regarded as two types of viruses. Viruses under DuCV1 and DuCV2 are further clustered into different sublineages. When analyzed using the method for genotype definition proposed by Grau-Roma et al, these different sublineages can be defined as genotypes DuCV1a, DuCV1b, DuCV2a, DuCV2b, and DuCV2c. In addition, the viral sequences obtained from mainland China are different in genomic size and share a diversity of no less than 13.2%, including the sequences that came from all genotypes. This suggests that the DuCVs prevalent in domestic duck flocks in China are ecologically divergent.

Physical Parameters Effect on Ozone-initiated Formation of Indoor Secondary Organic Aerosols with Emissions from Cleaning Products

Journal of Hazardous Materials. Sep, 2011  |  Pubmed ID: 21798666

The effect of air exchange rate (ACH), temperature (T), and relative humidity (RH) on the formation of indoor secondary organic aerosols (SOAs) through ozonolysis of biogenic organic compounds (BVOCs) emitted from floor cleaner was investigated in this study. The total particle count (with D(p) of 6-225 nm) was up to 1.2 × 10(3)#cm(-3) with ACH of 1.08 h(-1), and it became much more significant with ACH of 0.36 h(-1) (1.1 × 10(4)#cm(-3)). This suggests that a higher ventilation rate can effectively dilute indoor BVOCs, resulting in a less ultrafine particle formation. The total particle count increased when temperature changed from 15 to 23 °C but it decreased when the temperature further increased to 30 °C. It could be explained that high temperature restrained the condensation of formed semi-volatile compounds resulting in low yields of SOAs. When the RH was at 50% and 80%, SOA formation (1.1-1.2 × 10(4)#cm(-3)) was the more efficient compared with that at RH of 30% (5.9 × 10(3)#cm(-3)), suggesting higher RH facilitating the initial nucleation processes. Oxidation generated secondary carbonyl compounds were also quantified. Acetone was the most abundant carbonyl compound. The formation mechanisms of formaldehyde and acetone were proposed.

Electrophysiological Properties of Heteromeric TRPV4-C1 Channels

Biochimica Et Biophysica Acta. Dec, 2011  |  Pubmed ID: 21871867

We previously reported that TRPV4 and TRPC1 can co-assemble to form heteromeric TRPV4-C1 channels [12]. In the present study, we characterized some basic electrophysiological properties of heteromeric TRPV4-C1 channels. 4α-Phorbol 12,13-didecanoate (4α-PDD, a TRPV4 agonist) activated a single channel current in HEK293 cells co-expressing TRPV4 and TRPC1. The activity of the channels was abrogated by a TRPC1-targeting blocking antibody T1E3. Conductance of the channels was ~95pS for outward currents and ~83pS for inward currents. The channels with similar conductance were also recorded in cells expressing TRPV4-C1 concatamers, in which assembled channels were expected to be mostly 2V4:2C1. Fluorescence Resonance Energy Transfer (FRET) experiments confirmed the formation of a protein complex with 2V4:2C1 stoichiometry while suggesting an unlikeliness of 3V4:1C1 or 1V4:3C1 stoichiometry. Monovalent cation permeability profiles were compared between heteromeric TRPV4-C1 and homomeric TRPV4 channels. For heteromeric TRPV4-C1 channels, their permeation profile was found to fit to Eisenman sequence VI, indicative of a strong field strength cation binding site, whereas for homomeric TRPV4 channels, their permeation profile corresponded to Eisenman sequence IV for a weak field strength binding site. Compared to homomeric TRPV4 channels, heteromeric TRPV4-C1 channels were slightly more permeable to Ca2+ and had a reduced sensitivity to extracellular Ca2+ inhibition. In summary, we found that, when TRPV4 and TRPC1 were co-expressed in HEK293 cells, the predominate assembly type was 2V4:2C1. The heteromeric TRPV4-C1 channels display distinct electrophysiological properties different from those of homomeric TRPV4 channels.

Endothelial Nitric Oxide Synthase Enhancer Reduces Oxidative Stress and Restores Endothelial Function in Db/db Mice

Cardiovascular Research. Nov, 2011  |  Pubmed ID: 21875904

Endothelial dysfunction is caused by reduced nitric oxide (NO) bioavailability and/or over-produced reactive oxygen species (ROS). The present study investigated a vascular benefit of AVE3085, an endothelial nitric oxide synthase (eNOS) enhancer, in preserving endothelial function in diabetic mice and the mechanisms involved.

Estrogen Controls Embryonic Stem Cell Proliferation Via Store-operated Calcium Entry & the Nuclear Factor of Activated T-cells (NFAT)

Journal of Cellular Physiology. Aug, 2011  |  Pubmed ID: 21898397

Embryonic stem cells (ESCs) can self-renew indefinitely and differentiate into all cell lineages. Calcium is a universal second messenger which regulates a number of cellular pathways. Previous studies showed that store-operated calcium channels (SOCCs) but not voltage-operated calcium channels are present in mouse ESCs (mESCs). In this study, store-operated calcium entry (SOCE) was found to exist in mESCs using confocal microscopy. SOCC blockers lanthanum, 2-aminoethoxydiphenyl borate (2-APB) and SKF-96365 reduced mESC proliferation in a concentration-dependent manner, suggesting that SOCE is important for ESC proliferation. Pluripotent markers, Sox-2, Klf-4 and Nanog, were down-regulated by 2-APB, suggesting that self-renewal property of mESCs relies on SOCE. 17β-estradiol (E2) enhanced mESC proliferation. This enhanced proliferation was associated with an increment of SOCE. Both stimulated proliferation and increased SOCE could be reversed by SOCC blockers suggesting that E2 mediates its stimulatory effect on proliferation via enhancing SOCE. Also, cyclosporin A and INCA-6, inhibitors of calcineurin [phosphatase that de-phosphorylates and activates nuclear factor of activated T-cells (NFAT)], reversed the proliferative effect of E2, indicating that NFAT is involved in E2-stimulated proliferation. Interestingly, E2 caused the nuclear translocation of NFATc4, and this could be reversed by 2-APB. These results suggested that NFATc4 is the downstream target of E2-induced SOCE. The present investigation provides the first line of evidence that SOCE and NFAT are crucial for ESCs to maintain their unique characteristics. In addition, the present investigation also provides novel information on the mechanisms of how E2, an important female sex hormone, affects ESC proliferation. J. Cell. Physiol. © 2011 Wiley-Liss, Inc.

Rose-like Monodisperse Bismuth Subcarbonate Hierarchical Hollow Microspheres: One-pot Template-free Fabrication and Excellent Visible Light Photocatalytic Activity and Photochemical Stability for NO Removal in Indoor Air

Journal of Hazardous Materials. Nov, 2011  |  Pubmed ID: 21903327

Rose-like monodisperse hierarchical (BiO)(2)CO(3) hollow microspheres are fabricated by a one-pot template-free method for the first time based on hydrothermal treatment of ammonia bismuth citrate and urea in water. The microstructure and band structure of the as-prepared (BiO)(2)CO(3) superstructure are characterized in detail by X-ray diffraction, Raman spectroscopy, Fourier transform-infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, N(2) adsorption-desorption isotherms, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The monodisperse hierarchical (BiO)(2)CO(3) microspheres are constructed by the self-assembly of single-crystalline nanosheets. The aggregation of nanosheets result in the formation of three dimensional hierarchical framework containing mesopores and macropores, which is favorable for efficient transport of reaction molecules and harvesting of photo-energy. The result reveals the existence of special two-band-gap structure (3.25 and 2.0 eV) for (BiO)(2)CO(3). The band gap of 3.25 eV is intrinsic and the formation of smaller band gap of 2.0 eV can be ascribed to the in situ doped nitrogen in lattice. The performance of hierarchical (BiO)(2)CO(3) microspheres as efficient photocatalyst are further demonstrated in the removal of NO in indoor air under both visible light and UV irradiation. It is found that the hierarchical (BiO)(2)CO(3) microspheres not only exhibit excellent photocatalytic activity but also high photochemical stability during long term photocatalytic reaction. The special microstructure, the high charge separation efficiency due to the inductive effect, and two-band-gap structure in all contribute to the outstanding photocatalytic activities. The discovery of monodisperse hierarchical nitrogen doped (BiO)(2)CO(3) hollow structure is significant because of its potential applications in environmental pollution control, solar energy conversion, catalysis and other related areas.

Improved Liquid Chromatography-MS/MS of Heparan Sulfate Oligosaccharides Via Chip-based Pulsed Makeup Flow

Analytical Chemistry. Nov, 2011  |  Pubmed ID: 21923145

Microfluidic chip-based hydrophilic interaction chromatography (HILIC) is a useful separation system for liquid chromatography-mass spectrometry (LC-MS) in compositional profiling of heparan sulfate (HS) oligosaccharides; however, ions observed using HILIC LC-MS are low in charge. Tandem MS of HS oligosaccharide ions with low charge results in undesirable losses of SO(3) from precursor ions during collision induced dissociation. One solution is to add metal cations to stabilize sulfate groups. Another is to add a nonvolatile, polar compound such as sulfolane, a molecule known to supercharge proteins, to produce a similar effect for oligosaccharides. We demonstrate use of a novel pulsed makeup flow (MUF) HPLC-chip. The chip enables controlled application of additives during specified chromatographic time windows and thus minimizes the extent to which nonvolatile additives build up in the ion source. The pulsed MUF system was applied to LC-MS/MS of HS oligosaccharides. Metal cations and sulfolane were tested as additives. The most promising results were obtained for sulfolane, for which supercharging of the oligosaccharide ions increased their signal strengths relative to controls. Tandem MS of these supercharged precursor ions showed decreased abundances of product ions from sulfate losses yet more abundant product ions from backbone cleavages.

APPL1 Counteracts Obesity-induced Vascular Insulin Resistance and Endothelial Dysfunction by Modulating the Endothelial Production of Nitric Oxide and Endothelin-1 in Mice

Diabetes. Nov, 2011  |  Pubmed ID: 21926268

Insulin stimulates both nitric oxide (NO)-dependent vasodilation and endothelin-1 (ET-1)-dependent vasoconstriction. However, the cellular mechanisms that control the dual vascular effects of insulin remain unclear. This study aimed to investigate the roles of the multidomain adaptor protein APPL1 in modulating vascular actions of insulin in mice and in endothelial cells.

Morphology-dependent Voltage Sensitivity of a Gold Nanostructure

Langmuir : the ACS Journal of Surfaces and Colloids. Nov, 2011  |  Pubmed ID: 21951077

Gold nanostructures of various morphologies, including nanospheres, nanorods, nanoprisms, and thin films, were immobilized on ITO-coated coverslips in order to investigate the response of their scattering to potential. Shifts in the plasmon band obtained by potential-modulated spectroscopic imaging indicated that the voltage sensitivity of the gold nanostructure is dependent on its morphology, with nanospheres exhibiting the lowest sensitivity and ultrathin gold films exhibiting the highest. The effects of potential on gold nanoparticles are in qualitative agreement with Mie and Gans' theories in which the shift of the gold plasma frequency is due to the charging-discharging of the nanoparticles.

Oxidative Stress-dependent Cyclooxygenase-2-derived Prostaglandin F(2α) Impairs Endothelial Function in Renovascular Hypertensive Rats

Antioxidants & Redox Signaling. Feb, 2012  |  Pubmed ID: 21951274

Abstract Aims: The role of endothelium-derived contracting factors (EDCFs) in regulating renovascular function is yet to be elucidated in renovascular hypertension (RH). The current study investigated whether oxidative stress-dependent cyclooxygenase (COX)-2-derived prostaglandin F(2α) (PGF(2α)) impairs endothelial function in renal arteries of renovascular hypertensive rats (RHR). Results: Renal hypertension was induced in rats by renal artery stenosis of both kidneys using the 2-kidney 2-clip model. Acute treatment with reactive oxygen species (ROS) scavengers, COX-2 inhibitors, and thromboxane-prostanoid receptor antagonists, but not COX-1 inhibitors, improved endothelium-dependent relaxations and eliminated endothelium-dependent contractions in RHR renal arteries. Five weeks of treatment with celecoxib or tempol reduced blood pressure, increased renal blood flow, and restored endothelial function in RHRs. Increased ROS production in RHR arteries was inhibited by ROS scavengers, but unaffected by COX-2 inhibitors; whereas increased PGF(2α) release was reduced by both ROS scavengers and COX-2 inhibitors. ROS also induced COX-2-dependent contraction in RHR renal arteries, which was accompanied by the release of COX-2-derived PGF(2α). Further, chronic tempol treatment reduced COX-2 and BMP4 upregulation, p38MAPK phosphorylation, and the nitrotyrosine level in RHR renal arteries. Conclusion: These findings demonstrate the functional importance of oxidative stress, which serves as an initiator of increased COX-2 activity, and that COX-2-derived PGF(2α) plays an important role in mediating endothelial dysfunction in RH. Innovation: The current study, thus, suggests that drugs targeting oxidative stress-dependent COX-2-derived PGF(2α) may be useful in the prevention and management of RH. Antioxid. Redox Signal. 16, 363-373.

Postoperative Low Pelvic Radiotherapy and Chemotherapy for Stage II and III Rectal Cancer

American Journal of Clinical Oncology. Feb, 2012  |  Pubmed ID: 21297432

To evaluate whether postoperative low pelvic radiotherapy (RT) combined with chemotherapy is an appropriate treatment for stage II and III rectal cancer.

Graphene-supported Hemin As a Highly Active Biomimetic Oxidation Catalyst

Angewandte Chemie (International Ed. in English). Apr, 2012  |  Pubmed ID: 22368046

Well supported: stable hemin-graphene conjugates formed by immobilization of monomeric hemin on graphene, showed excellent catalytic activity, more than 10 times better than that of the recently developed hemin-hydrogel system and 100 times better than that of unsupported hemin. The catalysts also showed excellent binding affinities and catalytic efficiencies approaching that of natural enzymes.

Reversible Single-molecule Switching in an Ordered Monolayer Molecular Dipole Array

Small (Weinheim an Der Bergstrasse, Germany). May, 2012  |  Pubmed ID: 22378634

Making electronic devices using a single molecule has been the ultimate goal of molecular electronics. For binary data storage in particular, the challenge has been the ability to switch a single molecule in between bistable states in a simple and repeatable manner. The reversible switching of single molecules of chloroaluminum phthalocyanine (ClAlPc) dipolar molecules within a close-packed monolayer is demonstrated. By pulsing an scanning tunneling microscopy tip, read-write operations of single-molecular binary bits at ~40 Tb/cm(2) (~250 Tb/in(2)) are demonstrated.

Complete Genomic Sequence of a New Muscovy Duck-origin Reovirus from China

Journal of Virology. Nov, 2012  |  Pubmed ID: 23087110

The complete genomic sequence of a new Muscovy duck-origin reovirus (N-MDRV), strain J18 from China, was determined. The virus has a tricistronic S1 genome segment that is distinct from the originally described MDRV, which possesses a bicistronic S4 genome segment. Pairwise comparisons and phylogenetic analyses suggest that N-MDRV J18 is a new isolate within the species Avian orthoreovirus.

Peroxisome Proliferator-Activated Receptor-γ Ameliorates Pulmonary Arterial Hypertension by Inhibiting 5-Hydroxytryptamine 2B Receptor

Hypertension. Dec, 2012  |  Pubmed ID: 23108648

An elevated plasma level of 5-hydroxytryptamine (5-HT) or upregulation of 5-HT receptor signaling or both is implicated in vascular contraction and remodeling in pulmonary arterial hypertension (PAH). Recently, peroxisome proliferator-activated receptor-γ (PPARγ) agonists have been shown to ameliorate PAH. However, their effects on the 5-HT-induced contraction of pulmonary arteries remain unknown. Here, we examined the role of PPARγ in inhibiting 5-HT2B receptor (5-HT2BR) to ameliorate PAH. Pulmonary arteries from PAH rats induced by monocrotaline or chronic hypoxia showed an enhanced vasoconstriction in response to BW723C86, a specific agonist for 5-HT2BR. Expression of 5-HT2BR was also increased in pulmonary arteries from the PAH rats, accompanied by vascular remodeling and right ventricular hypertrophy. Treatment with the PPARγ agonist rosiglitazone in vivo reversed the expression and the vasocontractive effect of 5-HT2BR as well as the thickening of pulmonary arteries. In pulmonary artery smooth muscle cells, 5-HT induced the gene expression of 5-HT2BR, which was inhibited by rosiglitazone, pioglitazone, or adenovirus-mediated overexpression of constitutively activated PPARγ. The pharmacological effect of PPARγ was through the suppression of the 5-HT-induced activator protein-1 activity. These results demonstrated the beneficial effect of PPARγ on 5-HT2BR-mediated vasocontraction, providing a new mechanism for the potential use of PPARγ agonists in PAH.

The Effects of the 11 KDa Protein and the Putative X Protein on the P6 Promoter Activity of Parvovirus B19 in Hela Cells

Virus Genes. Nov, 2012  |  Pubmed ID: 23114653

Human parvovirus B19 (B19) is a small nonenveloped icosahedral virus with a single-stranded, linear 5.6 kb DNA genome. The p6 promoter, at map unit 6 of the viral genome, controls the expression of all B19 transcripts. Some previous reports revealed that this promoter is transactivated by NS1 protein. In an attempt to investigate the roles of other small viral proteins in the control of the p6 promoter activity, various truncated promoter/reporter constructs along with these nonstructural protein expression vectors were introduced into Hela cells. The results showed that the putative X protein upregulated the activity of p6 promoter significantly, but that the 11 kDa protein did not. Furthermore, the possible responsive DNA elements for X protein were identified to be located primarily between nt 265 and 343 of the p6 promoter region. In addition, we observed that deletion of the potential ATF/CREB binding sites located in 5' terminal nucleotide influenced the activity of p6 promoter significantly.

Correction: Role of TRPM2 in H(2)O(2)-Induced Cell Apoptosis in Endothelial Cells

PloS One. 2012  |  Pubmed ID: 23118841

[This corrects the article on p. e43186 in vol. 7.].

Boldine Protects Endothelial Function in Hyperglycemia-induced Oxidative Stress Through an Antioxidant Mechanism

Biochemical Pharmacology. Nov, 2012  |  Pubmed ID: 23178655

Increased oxidative stress is involved in the pathogenesis and progression of diabetes. Antioxidants are therapeutically beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1,10-dimethoxyaporphine) is a major alkaloid present in the leaves and bark of the boldo tree (Peumus boldus Molina), with known an antioxidant activity. This study examined the protective effects of boldine against high glucose-induced oxidative stress in rat aortic endothelial cells (RAEC) and its mechanisms of vasoprotection related to diabetic endothelial dysfunction. In RAEC exposed to high glucose (30mM) for 48hours, pre-treatment with boldine reduced the elevated ROS and nitrotyrosine formation, and preserved nitric oxide (NO) production. Pre-incubation with β-NAPDH reduced the acetylcholine-induced endothelium-dependent relaxation; this attenuation was reversed by boldine. Compared with control, endothelium-dependent relaxation in the aortas of streptozotocin (STZ)-treated diabetic rats was significantly improved by both acute (1μM, 30min) and chronic (20mg/kg/daily, i.p., 7 days) treatment with boldine. Intracellular superoxide and peroxynitrite formation measured by DHE fluorescence or chemiluminescence assay were higher in sections of aortic rings from diabetic rats compared with control. Chronic boldine treatment normalized ROS over-production in the diabetic group and this correlated with reduction of NAD(P)H oxidase subunits, NOX2 and p47(phox). The present study shows that boldine reversed the increased ROS formation in high glucose-treated endothelial cells and restored endothelial function in STZ-induced diabetes by inhibiting oxidative stress and thus increasing NO bioavailability.

Endothelial Dysfunction in Diabetes and Hypertension: Cross Talk in RAS, BMP4 and ROS-dependent COX-2-derived Prostanoids

Journal of Cardiovascular Pharmacology. Dec, 2012  |  Pubmed ID: 23232839

ABSTRACT: Vascular endothelium regulates cardiovascular function and endothelial dysfunction is the key initiator for arteriosclerosis and thrombosis, and their complications. The endothelium is a dynamic interface that responds to various stimuli and synthesizes and liberates vasoactive molecules such as nitric oxide, prostaglandins, hyperpolarizing factor and endothelin. Risk factors such as hypertension, hypercholesterolemia, smoking and hyperglycemia impair the ability of the endothelium to respond to physical or chemical stimulation appropriately and increased oxidative stress is believed to be a major culprit. This brief article reviews the interplay among several oxidative stress regulators in the vascular wall and highlights therapeutic relevance through deeper understanding of the interplay between the renin-angiotensin system, NADPH oxidase, bone morphogenic protein 4, and cyclooxygenase-2-derived prostaglandins as a concerted pathogenic cascade in inducing and maintaining endothelial dysfunction in hypertension and diabetes.

Carbonyl Emissions from Vehicular Exhausts Sources in Hong Kong

Journal of the Air & Waste Management Association (1995). Feb, 2012  |  Pubmed ID: 22442938

Vehicular emission (VE) is one of the important anthropogenic sources for airborne carbonyls in urban area. Six types of VE-dominated samples were collected at representative locations in Hong Kong where polluted by a particular fueled type of vehicles, including (i) a gas refilling taxis station (liquefied petroleum gas [LPG] emission); (ii) a light-duty passenger car park (gasoline emission); (iii) a minibus station (diesel emission); (iv) a single-deck-bus depot (diesel emission); (v) a double-deck-bus depot (diesel emission); and (vi) a whole-food market entrance for light- and heavy-duty vehicles (diesel emission). A total of 15 carbonyls in the samples were quantified. Formaldehyde was the most abundant carbonyl among the VE-dominated samples, and its contribution to the total quantified amount on a molar basis ranged from 54.8% to 60.8%. Acetaldehyde and acetone were the next two abundant carbonyls. The carbonyls were quantified at three roadside locations in Hong Kong. The highest concentrations of formaldehyde and acetaldehyde, 22.7 +/- 8.4 and 6.0 +/- 2.8 microg/m3, respectively, were determined in the samples collected at a main transportation gate for goods between Hong Kong and Mainland China. The total quantified carbonyl concentration, 37.9 +/- 9.3 microg/m3, was the highest at an entrance of a cross-harbor tunnel in downtown area. The theoretical carbonyls compositions of the three roadside locations were estimated according to the VE-dominated sample profiles and the statistics on vehicle numbers and types during the sampling period. The measured compositions of formaldehyde were much higher than the theoretical compositions in summer, demonstrating that photochemical reactions significantly contributed to the formaldehyde production in the roadsides.

Uncoupling Protein-2 Protects Endothelial Function in Diet-induced Obese Mice

Circulation Research. Apr, 2012  |  Pubmed ID: 22461387

Previous studies indicate uncoupling protein-2 (UCP2) as an antioxidant defense against endothelial dysfunction in hypertension. UCP2 also regulates insulin secretion and action. However, the role of UCP2 in endothelial dysfunction associated with diabetes and obesity is unclear.

Capsaicinoids Lower Plasma Cholesterol and Improve Endothelial Function in Hamsters

European Journal of Nutrition. Mar, 2012  |  Pubmed ID: 22466858

PURPOSE: Capsaicinoids are the active compounds in chili pepper. The present study investigated the effect of capsaicinoids on plasma lipids, functionality of aorta including atherosclerotic plaque development, cholesterol absorption biomarker, fecal sterol excretion, and gene expression of major receptors, enzymes, and transporters involved in cholesterol metabolism. METHODS: Hamsters were divided into five groups and fed a high-cholesterol diet containing 0 % (CON), 0.010 % (LD), 0.015 % (MD), 0.020 % (HD), and 0.030 % (VD) capsaicinoids, respectively, for 6 weeks. Plasma lipids were measured using the enzymatic kits, and the gene expression of transporters, enzymes, and receptors involved in cholesterol absorption and metabolism was quantified using the quantitative PCR. Endothelial function was assessed by measuring the acetylcholine-induced endothelium-dependent relaxations in aorta. RESULTS: Capsaicinoids reduced plasma total cholesterol, non-high-density lipoprotein cholesterol, and triacylglycerols with high-density lipoprotein cholesterol being unaffected. All four experimental groups had a decrease in the atherosclerotic plaque compared with CON. Dietary capsaicinoids increased the fecal excretion of total acidic sterols possibly mediated by up-regulation of cholesterol 7α-hydroxylase and down-regulation of liver X receptor alpha. Plasma sterol analysis demonstrated that capsaicinoids decreased the ratio of plasma campesterol/cholesterol, suggesting they decreased cholesterol absorption. Capsaicinoids could improve the endothelium-dependent relaxations and reduce the endothelium-dependent contractions by inhibiting the gene expression of COX-2. However, no dose-dependent effect of capsaicinoids on these parameters was seen. CONCLUSION: Capsaicinoids were beneficial in improving lipoprotein profile and aortic function in hamsters fed a high-cholesterol diet.

Domain Wall Motion in Synthetic Co2Si Nanowires

Nano Letters. Apr, 2012  |  Pubmed ID: 22469009

We report the synthesis of single crystalline Co(2)Si nanowires and the electrical transport studies of single Co(2)Si nanowire devices at low temperature. The butterfly shaped magnetoresistance shows interesting ferromagnetic features, including negative magnetoresistance, hysteretic switch fields, and stepwise drops in magnetoresistance. The nonsmooth stepwise magnetoresistance response is attributed to magnetic domain wall pinning and depinning motion in the Co(2)Si nanowires probably at crystal or morphology defects. The temperature dependence of the domain wall depinning field is observed and described by a model based on thermally assisted domain wall depinning over a single energy barrier.

Protein Kinase G Inhibits Flow-induced Ca2+ Entry into Collecting Duct Cells

Journal of the American Society of Nephrology : JASN. Jul, 2012  |  Pubmed ID: 22518003

The renal cortical collecting duct (CCD) contributes to the maintenance of K(+) homeostasis by modulating renal K(+) secretion. Cytosolic Ca(2+) ([Ca(2+)](i)) mediates flow-induced K(+) secretion in the CCD, but the mechanisms regulating flow-induced Ca(2+) entry into renal epithelial cells are not well understood. Here, we found that atrial natriuretic peptide, nitric oxide, and cyclic guanosine monophosphate (cGMP) act through protein kinase G (PKG) to inhibit flow-induced increases in [Ca(2+)](i) in M1-CCD cells. Coimmunoprecipitation, double immunostaining, and functional studies identified heteromeric TRPV4-P2 channels as the mediators of flow-induced Ca(2+) entry into M1-CCD cells and HEK293 cells that were coexpressed with both TRPV4 and TRPP2. In these HEK293 cells, introducing point mutations at two putative PKG phosphorylation sites on TRPP2 abolished the ability of cGMP to inhibit flow-induced Ca(2+) entry. In addition, treating M1-CCD cells with fusion peptides that compete with the endogenous PKG phosphorylation sites on TRPP2 also abolished the cGMP-mediated inhibition of the flow-induced Ca(2+) entry. Taken together, these data suggest that heteromeric TRPV4-P2 channels mediate the flow-induced entry of Ca(2+) into collecting duct cells. Furthermore, substances such as atrial natriuretic peptide and nitric oxide, which increase cGMP, abrogate flow-induced Ca(2+) entry through PKG-mediated inhibition of these channels.

[Sequence Comparison of the Hemagglutinin Gene of the Duck-origin H9N2 Subtype Avian Influenza Viruses]

Bing Du Xue Bao = Chinese Journal of Virology / [bian Ji, Bing Du Xue Bao Bian Ji Wei Yuan Hui]. Mar, 2012  |  Pubmed ID: 22519178

To demonstrate the phylogenetic evolution, the molecular characteristics of the motif of HA protein cleavage site and the varieties at the receptor binding sites of the hemagglutinin gene of the duck-origin H9N2 subtype avian influenza viruses, sequence alignment and phylogenetic analysis were performed by MEGA 4.1 Neighbor-Joining method.. The results revealed that the duck-origin H9N2 AIV viruses originated from CK/BJ/1/94-like and North-Ame-like, all the duck-origin H9N2 AIV viruses from mainland China belonged to CK/BJ/1/94-like and formed multiple genotypes through complicated re-assortment, while other duck-origin H9N2 AIV, isolated from other countries in Aisa, American and European such as Korea, Japan, Alberta, Austria, Switzerland, Iran, belonged to the North-Ame-like phylogenetic lineage. The amino acids at positions 183, 190, and 226 of the receptor binding sites of North-Ame-like group isolates had highly conserved H, E and Q respectively. In contrast with duck-origin H9N2 AIV viruses isolates from mainland China, the amino acids had N at positions 183, A, T, or V at 190, L or Q at 226, which was the same as the chicken-origin H9N2 AIV from mainland China. Most newly isolated chicken-origin H9N2 AIV in Fujian Province in Southern China had L at position 226 emphasized the higher risk of cross-infection between the chicken-origin and duck-origin H9N2 AIV in China.

In Vivo Reprogramming of Murine Cardiac Fibroblasts into Induced Cardiomyocytes

Nature. May, 2012  |  Pubmed ID: 22522929

The reprogramming of adult cells into pluripotent cells or directly into alternative adult cell types holds great promise for regenerative medicine. We reported previously that cardiac fibroblasts,which represent 50%of the cells in the mammalian heart, can be directly reprogrammed to adult cardiomyocyte-like cells in vitro by the addition of Gata4, Mef2c and Tbx5 (GMT). Here we use genetic lineage tracing to show that resident non-myocytes in the murine heart can be reprogrammed into cardiomyocyte-like cells in vivo by local delivery of GMT after coronary ligation. Induced cardiomyocytes became binucleate, assembled sarcomeres and had cardiomyocyte-like gene expression. Analysis of single cells revealed ventricular cardiomyocyte-like action potentials, beating upon electrical stimulation, and evidence of electrical coupling. In vivo delivery of GMT decreased infarct size and modestly attenuated cardiac dysfunction up to 3 months after coronary ligation. Delivery of the pro-angiogenic and fibroblast-activating peptide, thymosin b4, along with GMT, resulted in further improvements in scar area and cardiac function. These findings demonstrate that cardiac fibroblasts can be reprogrammed into cardiomyocyte-like cells in their native environment for potential regenerative purposes.

Brain Slice on a Chip: Opportunities and Challenges of Applying Microfluidic Technology to Intact Tissues

Lab on a Chip. Jun, 2012  |  Pubmed ID: 22534786

Isolated brain tissue, especially brain slices, are valuable experimental tools for studying neuronal function at the network, cellular, synaptic, and single channel levels. Neuroscientists have refined the methods for preserving brain slice viability and function and converged on principles that strongly resemble the approach taken by engineers in developing microfluidic devices. With respect to brain slices, microfluidic technology may 1) overcome the traditional limitations of conventional interface and submerged slice chambers and improve oxygen/nutrient penetration into slices, 2) provide better spatiotemporal control over solution flow/drug delivery to specific slice regions, and 3) permit successful integration with modern optical and electrophysiological techniques. In this review, we highlight the unique advantages of microfluidic devices for in vitro brain slice research, describe recent advances in the integration of microfluidic devices with optical and electrophysiological instrumentation, and discuss clinical applications of microfluidic technology as applied to brain slices and other non-neuronal tissues. We hope that this review will serve as an interdisciplinary guide for both neuroscientists studying brain tissue in vitro and engineers as they further develop microfluidic chamber technology for neuroscience research.

Kinetic Competition Model and Size-dependent Phase Selection in 1-D Nanostructures

Nano Letters. Jun, 2012  |  Pubmed ID: 22545743

The first phase selection and the phase formation sequence between metal and silicon (Si) couples are indispensably significant to microelectronics. With increasing scaling of device dimension to nano regime, established thermodynamic and kinetic models in bulk and thin film fail to apply in 1-D nanostructures. Herein, we present an unique size-dependent first phase formation sequence in 1-D nanostructures, with Ni-Si as the model system. Interfacial-limited phase which forms the last in thin film, NiSi(2), appears as the dominant first phase at 300-800 °C due to the elimination of continuous grain boundaries in 1-D silicides. On the other hand, θ-Ni(2)Si, the most competitive diffusion-limited phase takes over NiSi(2) and wins out as the first phase in small diameter nanowires at 800 °C. Kinetic parameters extracted from in situ transmission electron microscope studies and a modified kinetic growth competition model quantitatively explain this observation. An estimated critical diameter from the model agrees reasonably well with observations.

PI3-kinase/Akt Pathway-regulated Membrane Insertion of Acid-sensing Ion Channel 1a Underlies BDNF-induced Pain Hypersensitivity

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience. May, 2012  |  Pubmed ID: 22553040

Central neural plasticity plays a key role in pain hypersensitivity. This process is modulated by brain-derived neurotrophic factor (BDNF) and also involves the type 1a acid-sensing ion channel (ASIC1a). However, the interactions between the BDNF receptor, tropomyosin-related kinase B (TrkB), and ASIC1a are unclear. Here, we show that deletion of ASIC1 gene suppressed the sustained mechanical hyperalgesia induced by intrathecal BDNF application in mice. In both rat spinal dorsal horn neurons and heterologous cell cultures, the BDNF/TrkB pathway enhanced ASIC1a currents via phosphoinositide 3-kinase (PI3K)-protein kinase B (PKB/Akt) cascade and phosphorylation of cytoplasmic residue Ser-25 of ASIC1a, resulting in enhanced forward trafficking and increased surface expression. Moreover, in both rats and mice, this enhanced ASIC1a activity was required for BDNF-mediated hypersensitivity of spinal dorsal horn nociceptive neurons and central mechanical hyperalgesia, a process that was abolished by intrathecal application of a peptide representing the N-terminal region of ASIC1a encompassing Ser-25. Thus, our results reveal a novel mechanism underlying central sensitization and pain hypersensitivity, and reinforce the critical role of ASIC1a channels in these processes.

Pharmacotherapy of Obstructive Sleep Apnea

Expert Opinion on Pharmacotherapy. Apr, 2012  |  Pubmed ID: 22424320

INTRODUCTION: Obstructive sleep apnea syndrome is a common public health problem in the general population. The important health-related consequences of obstructive sleep apnea include cardiovascular disorders, such as myocardial infarction and hypertension, stroke, sudden death and difficult blood sugar control related to diabetes mellitus. The current main treatment options include body weight loss, continuous positive airway pressure, oral appliances and surgical treatment. The effects of pharmacotherapy on sleep apnea continue to be controversial and supplemental only. Current medications for sleep apnea mainly act through reducing risk factors, treating predisposing endocrine disorders, improving residual sleepiness post management and controlling associated hypertension and metabolic disorders. AREAS COVERED: This article discusses the pharmacotherapy of sleep apnea, including ventilatory stimulants, serotoninergic and REM sleep suppressant agents, acetylcholinesterase inhibitors, medications for predisposing endocrine disorders, stimulants, associated sleep apnea health problems and sleep apnea patient anesthetic precaution. Weight loss is not a direct pharmacological approach and is only briefly mentioned. EXPERT OPINION: At present, there is no appropriate pharmacological treatment for obstructive sleep apnea. There are adjunct treatments such as anti-allergy treatment, and, if residual sleepiness is present, nonamphetaminic stimulants can help. Usage of these stimulants will, however, produce negative effects in an anticipated rate of about 10% of subjects taking these medications.

An Investigation of Oxidative DNA Damage in Pharmacy Technicians Exposed to Antineoplastic Drugs in Two Chinese Hospitals Using the Urinary 8-OHdG Assay

Biomedical and Environmental Sciences : BES. Feb, 2012  |  Pubmed ID: 22424635

To investigate oxidative DNA damage in pharmacy technicians preparing antineoplastic drugs at the PIVAS (Pharmacy Intravenous Admixture Service) in two Chinese hospitals.

[Skin Lesions Induced by Malnutrition in an Infant with Methylmalonic Aciduria and Homocysteic Acidemia]

Zhongguo Dang Dai Er Ke Za Zhi = Chinese Journal of Contemporary Pediatrics. Mar, 2012  |  Pubmed ID: 22433417

Counteraction Between Angiotensin II and Angiotensin-(1-7) Via Activating Angiotensin Type I and Mas Receptor on Rat Renal Mesangial Cells

Regulatory Peptides. Aug, 2012  |  Pubmed ID: 22561449

In the updated concept of renin-angiotensin system (RAS), it contains the angiotensin converting enzyme (ACE)-angiotensin (Ang) II-angtiogensin type 1 receptor (AT1) axis and the angiotensin-converting enzyme-related carboxypeptidase (ACE2)-Ang-(1-7)-Mas axis. The former axis has been well demonstrated performing the vasoconstrictive, proliferative and pro-inflammatory functions by activation of AT1 receptors, while the later new identified axis is considered counterbalancing the effects of the former. The present study is aimed at observing the interaction between Ang-(1-7) and Ang II on cultured rat renal mesangial cells (MCs). RT-PCR, Western blot and immunofluorescent staining and confocal microscopy results showed that both AT1 and Mas receptor were co-distributed in rat renal MCs. Ang-(1-7) showed similar effects on Ang II in cultured MCs that stimulated phosphorylated extracellular signal-regulated kinase (ERK)1/2 phosphorylation and transforms growth factor-β1 synthesis, and cell proliferation and extracellular matrix synthesis. Co-treatment of the cell with Ang-(1-7) and Ang II, Ang-(1-7) counteracted AngII-induced effects in a concentration dependent manner, but failed to alter the changes induced by endothelin-1. The stimulating effect of Ang II was mediated by AT1 receptor while all the effects of Ang-(1-7) were blocked by Mas receptor antagonist A-779, but not by AT1 receptor antagonist losartan or AT2 receptor antagonist PD123319. These results suggest that Ang-(1-7) and Ang II specifically interact with each other on rat renal MCs via activation of their specific receptors, Mas and AT1 receptor respectively.

[Analysis of the Effect of Detector's Operating Temperature on SNR in Space-based Remote Sensor]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Mar, 2012  |  Pubmed ID: 22582653

Limb viewing is a new viewing geometry for space-based atmospheric remote sensing, but the spectral radiance of atmosphere scattering reduces rapidly with limb height. So the signal-noise-ratio (SNR) is a key performance parameter of limb remote sensor. A SNR model varying with detector's temperature is proposed, based on analysis of spectral radiative transfer and noise' source in representative instruments. The SNR at limb height 70 km under space conditions was validated by simulation experiment on limb remote sensing spectrometer prototype. Theoretic analysis and experiment's results indicate congruously that when detector's temperature reduces to some extent, a maximum SNR will be reached. After considering the power consumption, thermal conductivity and other issues, optimal operating temperature of detector can be decided.

NO and EDHF Pathways in Pulmonary Arteries and Veins Are Impaired in COPD Patients

Vascular Pharmacology. Sep-Oct, 2012  |  Pubmed ID: 22609132

We investigated endothelial function of both pulmonary arteries and veins in patients with chronic obstructive pulmonary disease (COPD) of varying severity in regard to the role of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). Lung tissues were obtained from patients undergoing lobectomy or pneumonectomy. Patients were grouped to control, moderate COPD, and severe COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Pulmonary arteries and veins were studied for endothelium-dependent relaxations. NO concentration was measured by electrochemical method. Protein expressions of eNOS and phosphorylated eNOS were determined by Western-blot. Endothelium-dependent relaxation was more significant in pulmonary arteries than in veins. The vasorelaxation was decreased in patients of moderate COPD and further decreased in severe COPD. The severity of endothelial dysfunction in both pulmonary arteries and veins correlated with the degree of airflow obstruction. COPD patients exhibited reduced endothelial NO production, decreased eNOS protein expression and decreased eNOS phosphorylation. The EDHF component was abolished in the pulmonary vasculature of patients with severe COPD. NO and EDHF pathways are both involved in the regulation of vascular tone in human pulmonary arteries and veins. Both pathways are impaired in COPD patients and the severity of the impairment increases with the progress of the disease. Downregulation of eNOS expression and inhibition of eNOS activation underlie the reduction of NO in COPD patients.

From Skeleton to Cytoskeleton: Osteocalcin Transforms Vascular Fibroblasts to Myofibroblasts Via Angiotensin II and Toll-like Receptor 4

Circulation Research. Jul, 2012  |  Pubmed ID: 22679141

The expression of osteocalcin is augmented in human atherosclerotic lesions. How osteocalcin triggers vascular pathogenesis and remodeling is unclear.

Blueberry Anthocyanins at Doses of 0.5 and 1 % Lowered Plasma Cholesterol by Increasing Fecal Excretion of Acidic and Neutral Sterols in Hamsters Fed a Cholesterol-enriched Diet

European Journal of Nutrition. Jun, 2012  |  Pubmed ID: 22684634

PURPOSE: The present study investigated the underlying mechanism associated with the hypocholesterolemic activity of blueberry anthocyanins by examining its effect on fecal sterol excretion and gene expression of major receptors, enzymes, and transporters involved in cholesterol metabolism. METHODS: Hamsters were divided into three groups and fed a 0.1 % cholesterol diet containing 0 % (CTL), 0.5 % (BL), and 1.0 % (BH) blueberry anthocyanins, respectively, for six weeks. Plasma total cholesterol (TC), triacylglycerols (TAG), and non-high-density lipoproteins cholesterol (non-HDL-C) were measured using the enzymatic kits, and the gene expression of transporters, enzymes, and receptors involved in cholesterol absorption and metabolism was quantified using the quantitative PCR. GC analysis was used to quantify hepatic cholesterol and fecal acidic and neutral sterols. RESULTS: Dietary supplementation of 0.5 and 1.0 % blueberry anthocyanins for 6 weeks decreased plasma TC concentration by 6-12 % in a dose-dependent manner. This was accompanied by increasing the excretion of fecal neutral and acidic sterols by 22-29 % and 41-74 %, respectively. Real-time PCR analyses demonstrated that incorporation of blueberry anthocyanins into diet down-regulated the genes of NPC1L1, ACAT-2, MTP, and ABCG 8. In addition, blueberry anthocyanins were also able to down-regulate the gene expression of hepatic HMG-CoA reductase. CONCLUSION: The cholesterol-lowering activity of blueberry anthocyanins was most likely mediated by enhancing the excretion of sterols accompanied with down-regulation on gene expression of intestinal NPC1L1, ACAT-2, MTP, and ABCG 8.

The Effects of Sound Level and Vibration Magnitude on the Relative Discomfort of Noise and Vibration

The Journal of the Acoustical Society of America. Jun, 2012  |  Pubmed ID: 22712930

The relative discomfort caused by noise and vibration, how this depends on the level of noise and the magnitude of vibration, and whether the noise and vibration are presented simultaneously or sequentially has been investigated in a laboratory study with 20 subjects. Noise and vertical vibration were reproduced with all 49 combinations of 7 levels of noise and 7 magnitudes of vibration to allow the discomfort caused by one of the stimuli to be judged relative to the other stimulus using magnitude estimation. In four sessions, subjects judged noise relative to vibration and vibration relative to noise, with both simultaneous and sequential presentations of the stimuli. The equivalence of noise and vibration was not greatly dependent on whether the stimuli were simultaneous or sequential, but highly dependent on whether noise was judged relative to vibration or vibration was judged relative to noise. When judging noise, higher magnitude vibrations appeared to mask the discomfort caused by low levels of noise. When judging vibration, higher level noises appeared to mask the discomfort caused by low magnitudes of vibration. The judgment of vibration discomfort was more influenced by noise than the judgment of noise discomfort was influenced by vibration.

Simplifying the Creation of Dumbbell-like Cu-Ag Nanostructures and Their Enhanced Catalytic Activity

Chemistry (Weinheim an Der Bergstrasse, Germany). Jul, 2012  |  Pubmed ID: 22740233

High-frequency Self-aligned Graphene Transistors with Transferred Gate Stacks

Proceedings of the National Academy of Sciences of the United States of America. Jul, 2012  |  Pubmed ID: 22753503

Graphene has attracted enormous attention for radio-frequency transistor applications because of its exceptional high carrier mobility, high carrier saturation velocity, and large critical current density. Herein we report a new approach for the scalable fabrication of high-performance graphene transistors with transferred gate stacks. Specifically, arrays of gate stacks are first patterned on a sacrificial substrate, and then transferred onto arbitrary substrates with graphene on top. A self-aligned process, enabled by the unique structure of the transferred gate stacks, is then used to position precisely the source and drain electrodes with minimized access resistance or parasitic capacitance. This process has therefore enabled scalable fabrication of self-aligned graphene transistors with unprecedented performance including a record-high cutoff frequency up to 427 GHz. Our study defines a unique pathway to large-scale fabrication of high-performance graphene transistors, and holds significant potential for future application of graphene-based devices in ultra-high-frequency circuits.

Synthesis of PtPd Bimetal Nanocrystals with Controllable Shape, Composition, and Their Tunable Catalytic Properties

Nano Letters. Aug, 2012  |  Pubmed ID: 22764838

We report a facile synthetic strategy to single-crystalline PtPd nanocrystals with controllable shapes and tunable compositions. In the developed synthesis, the molar ratio of the starting precursors determines the composition in the final PtPd nanocrystals, while the halides function as the shape-directing agent to induce the formation of PtPd nanocrystals with cubic or octahedral/tetrahedral morphology. These obtained PtPd nanocrystals exhibit high activity in the hydrogenation of nitrobenzene, and their performance is highly shape- and composition-dependent with Pt in ∼50% showing the optimum activity and the {100}-facet-enclosed PtPd nanocrystals demonstrating a higher activity than the {111}-facet-bounded PtPd nanocrystals.

Stabilization of High-performance Oxygen Reduction Reaction Pt Electrocatalyst Supported on Reduced Graphene Oxide/carbon Black Composite

Journal of the American Chemical Society. Aug, 2012  |  Pubmed ID: 22783832

Oxygen reduction reaction (ORR) catalyst supported by hybrid composite materials is prepared by well-mixing carbon black (CB) with Pt-loaded reduced graphene oxide (RGO). With the insertion of CB particles between RGO sheets, stacking of RGO can be effectively prevented, promoting diffusion of oxygen molecules through the RGO sheets and enhancing the ORR electrocatalytic activity. The accelerated durability test (ADT) demonstrates that the hybrid supporting material can dramatically enhance the durability of the catalyst and retain the electrochemical surface area (ECSA) of Pt: the final ECSA of the Pt nanocrystal on the hybrid support after 20 000 ADT cycles is retained at >95%, much higher than the commercially available catalyst. We suggest that the unique 2D profile of the RGO functions as a barrier, preventing leaching of Pt into the electrolyte, and the CB in the vicinity acts as active sites to recapture/renucleate the dissolved Pt species. We furthermore demonstrate that the working mechanism can be applied to the commercial Pt/C product to greatly enhance its durability.

[Investigation Analysis on Public Awareness of Tuberculosis Knowledge in Zhejiang Province, 2010]

Zhonghua Yu Fang Yi Xue Za Zhi [Chinese Journal of Preventive Medicine]. Apr, 2012  |  Pubmed ID: 22800636

To investigate the status of awareness on tuberculosis (TB) in the public and its impact factors in Zhejiang province.

Time-dependent Scattering of Ultrathin Gold Film Under Potential Perturbation

ACS Applied Materials & Interfaces. Aug, 2012  |  Pubmed ID: 22809099

Shifts of the plasmon scattering band of ultrathin gold films under the effect of dynamic applied potential were studied in single wavelength measurements. The effect on scattering of applied potential was ascribed to electronic charging and discharging of the gold film. Scattering transients in response to square-wave potential modulation had an exponential form which depended on the potential step width, the modulation frequency and the nature of the ions. The presence of an AC signal component induced by ±10 mV potential modulated at 2 kHz indicated the capability of very thin gold film to respond to high frequency voltage.

[Differential Diagnosis of Malignant and Benign Peripheral Pulmonary Lesions Based on Two Characteristic Echo Features of Endobronchial Ultrasonography]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Jun, 2012  |  Pubmed ID: 22820590

To assess the feasibility of endobronchial ultrasonography (EBUS) in the differential diagnosis of malignant and benign lesions based on the two characteristic echo features of malignancy.

Crystallinity Control of Ferromagnetic Contacts in Stressed Nanowire Templates and the Magnetic Domain Anisotropy

Nano Letters. Aug, 2012  |  Pubmed ID: 22823105

We report the controlled growth of single-crystalline ferromagnetic contacts through solid state reaction at nanoscale. Single-crystal Mn(5)Si(3) and Fe(5)Ge(3) contacts were grown within stressed Si and Ge nanowire templates, where oxide-shells were used to exert compressive stress on the silicide or germanide. Compared to polycrystalline silicide and germanide structures observed within bare nanowires, the built-in high strain in the oxide-shelled nanostructures alters the nucleation behavior of the ferromagnetic materials, leading to single crystal growth in the transverse/radial direction. Interestingly, the compressive stress is also found to affect the magnetic anisotropy of the ferromagnetic contacts. In-plane and out-of-plane magnetization were observed in Fe(5)Ge(3) for different crystal orientations, showing distinctly preferred domain orientations. These interesting results display the capability to control both the crystallinity and the magnetic anisotropy of ferromagnetic contacts in engineered nanostructures.

Tandem Mass Spectrometry of Heparan Sulfate Negative Ions: Sulfate Loss Patterns and Chemical Modification Methods for Improvement of Product Ion Profiles

Journal of the American Society for Mass Spectrometry. Sep, 2012  |  Pubmed ID: 22825743

Heparan sulfate (HS) is a polysaccharide modified with sulfation, acetylation, and epimerization that enable its binding with protein ligands and regulation of important biological processes. Tandem mass spectrometry has been employed to sequence linear biomolecules e.g., proteins and peptides. However, its application in structural characterization of HS is limited due to the neutral loss of sulfate (SO(3)) during collisional induced dissociation (CID). In this report, we studied the dissociation patterns of HS disaccharides and demonstrate that the N-sulfate (N-S) bond is especially facile during CID. We identified factors that influence the propensities of such losses from precursor ions and proposed a Free Proton Index (FPI) to help select ions that are able to produce meaningful backbone dissociations. We then investigated the thermodynamics and kinetics of SO(3) loss from sulfates that are protonated, deprotonated, and metal-adducted using density functional theory computations. The calculations showed that sulfate loss from a protonated site was much more facile than that from a deprotonated or metal-adducted site. Further, the loss of SO(3) from N-sulfate was energetically favored by 3-8 kcal/mol in transition states relative to O-sulfates, making it more prone to this process by a substantial factor. In order to reduce the FPI, representing the number of labile sulfates in HS native chains and oligosaccharides, we developed a series of chemical modifications to selectively replace the N-sulfates of the glucosamine with deuterated acetyl group. These modifications effectively reduced the sulfate density on the HS oligosaccharides and generated considerably more backbone dissociation using on-line LC/tandem MS.

Chronic Cranberry Juice Consumption Restores Cholesterol Profiles and Improves Endothelial Function in Ovariectomized Rats

European Journal of Nutrition. Jul, 2012  |  Pubmed ID: 22836513

PURPOSE: Postmenopausal women experience higher risks for cardiovascular diseases than age-matched men and pre-menopausal women. There is a need for better treatment strategy for estrogen-deficient-related cardiovascular complications. We and others have recently reported that activated renin-angiotensin system and the associated oxidative stress impaired endothelium-dependent relaxation in ovariectomized rat, while angiotensin receptor blocker rescues endothelial dysfunction. Dietary supplements and lifestyle modifications provide an alternative way to improve cardiovascular health. The present study tests the hypothesis that chronic cranberry juice consumption improves cholesterol profiles and vascular functions in estrogen-deficient animal model. The effect of cranberry consumption on expression and activity of renin-angiotensin system in the vasculature will be determined. METHODS: Ovariectomized rats were treated daily with commercial cranberry juice at 7 mg/kg for 8 weeks, a dosage comparable to recent clinical studies. Serum was collected for measuring cholesterol levels while aorta was isolated for isometric force assay and expression studies. RESULTS: Cranberry juice consumption reduced circulating levels of total cholesterol, triacylglycerols, HDL, nHDL, and nHDL/HDL ratio. Meanwhile, cranberry juice consumption improved endothelium-dependent relaxation in aorta of ovariectomized rats by restoring p-eNOS level (endothelial nitric oxide synthase phosphorylated at ser-1177), reversing the up-regulated levels of renin-angiotensin system markers (angiotensin-converting enzyme, angiotensin II, and angiotensin II type 1 receptor), and normalizing the elevated NAD(P)H oxidase expression and oxidative stress. CONCLUSIONS: Our data demonstrate the novel cardiovascular benefits of cranberry juice consumption in improving both vascular functions and cholesterol profiles, providing insight into developing cranberry products into useful dietary supplements for postmenopausal women.

(1-{[2-(6-Methoxynaphthalen-1-yl)ethyl]amino}ethylidene)oxidanium Bromide Monohydrate

Acta Crystallographica. Section C, Crystal Structure Communications. Aug, 2012  |  Pubmed ID: 22850857

The title salt, C(15)H(18)NO(2)(+)·Br(-)·H(2)O, is an analogue of the antidepressant drug agomelatine. The cation is protonated at the carbonyl O atom of its amide group. The side chain at the 1-position adopts an extended conformation, with all non-H atoms lying in the same plane as the naphthalene ring. This is in contrast with the crystal structures known for three agomelatine polymorphs, and also with two known cocrystals containing agomelatine. The structure displays three types of hydrogen bond, namely C=O-H···O, N-H···Br and O-H···Br, which define a two-dimensional network parallel to the (100) plane. The naphthalene rings interdigitate in a `zipper-like' fashion between these hydrogen-bonded networks, forming an offset arrangement. Direct face-to-face π-π contacts between naphthalene rings are not present in the structure.

Complete Genomic Sequence of the Virulent Bacteriophage RAP44 of Riemerella Anatipestifer

Avian Diseases. Jun, 2012  |  Pubmed ID: 22856189

A virulent Riemerella anatipestifer bacteriophage, RAP44, belonging to the Siphoviridae family of tailed phages, was previously isolated from feces of healthy Muscovy ducks in China. A complete genomic sequence analysis indicates that the phage's genome consists of a linear, double-stranded DNA molecule of 49,329 nucleotides. Eighty open reading frames (ORF) were identified. Putative functions could be assigned to 24 of the ORFs. The location of these genes was consistent with organization of the genome in a modular format which includes modules for host cell lysis, tail morphogenesis, head morphogenesis, and DNA replication and modification modules. Until now, no R. anatipestifer phage genome sequence has been reported in the literature. Therefore, this study represents the first complete genomic and molecular description of the R. anatipestifer phage.

Dipeptidyl Peptidase 4 Inhibitor Sitagliptin Protects Endothelial Function in Hypertension Through a Glucagon-like Peptide 1-dependent Mechanism

Hypertension. Sep, 2012  |  Pubmed ID: 22868389

Sitagliptin, a selective dipeptidyl peptidase 4 inhibitor, inhibits the inactivation and degradation of glucagon like peptide 1 (GLP-1), which is used for the treatment of type 2 diabetes mellitus. However, little is known about the role of GLP-1 in hypertension. This study investigated whether the activation of GLP-1 signaling protects endothelial function in hypertension. Two-week sitagliptin treatment (10 mg/kg per day, oral gavage) improved endothelium-dependent relaxation in renal arteries, restored renal blood flow, and reduced systolic blood pressure in spontaneously hypertensive rats. In vivo sitagliptin treatment elevated GLP-1 and GLP-1 receptor expressions, increased cAMP level, and subsequently activated protein kinase A, liver kinase B1, AMP-activated protein kinase-α and endothelial NO synthase in spontaneously hypertensive rat renal arteries. Inhibition of GLP-1 receptor, adenylyl cyclase, protein kinase A, AMP-activated protein kinase-α, or NO synthase reversed the protective effects of sitagliptin. We also demonstrate that GLP-1 receptor agonist exendin 4 in vitro treatment had similar vasoprotective effects in spontaneously hypertensive rat renal arteries and increased NO production in spontaneously hypertensive rat aortic endothelial cells. Studies using transient expressions of wild-type and dominant-negative AMP-activated protein kinase-α2 support the critical role of AMP-activated protein kinase-α in mediating the effect of GLP-1 in endothelial cells. Ex vivo exendin 4 treatment also improved endothelial function of renal arteries from hypertensive patients. Our results elucidate that upregulation of GLP-1 and related agents improve endothelial function in hypertension by restoring NO bioavailability, suggesting that GLP-1 signaling could be a therapeutic target in hypertension-related vascular events.

Differential Effects of Cystathionine-γ-lyase-Dependent Vasodilatory H(2)S in Periadventitial Vasoregulation of Rat and Mouse Aortas

PloS One. 2012  |  Pubmed ID: 22870268

BACKGROUND: Hydrogen sulfide (H(2)S) is a potent vasodilator. However, the complex mechanisms of vasoregulation by H(2)S are not fully understood. We tested the hypotheses that (1) H(2)S exerts vasodilatory effects by opening KCNQ-type voltage-dependent (K(v)) K(+) channels and (2) that H(2)S-producing cystathionine-γ-lyase (CSE) in perivascular adipose tissue plays a major role in this pathway. METHODOLOGY/PRINCIPAL FINDINGS: Wire myography of rat and mouse aortas was used. NaHS and 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADTOH) were used as H(2)S donors. KCNQ-type K(v) channels were blocked by XE991. 4-Propargylglycine (PPG) and ß-cyano-l-alanine (BCA), or 2-(aminooxy)-acetic acid (AOAA) were used as inhibitors of CSE or cystathionine-ß-synthase (CBS), respectively. NaHS and ADTOH produced strong vasorelaxation in rat and mouse aortas, which were abolished by KCNQ channel inhibition with XE991. Perivascular adipose tissue (PVAT) exerted an anticontractile effect in these arteries. CSE inhibition by PPG and BCA reduced this effect in aortas from rats but not from mice. CBS inhibition with AOAA did not inhibit the anticontractile effects of PVAT. XE991, however, almost completely suppressed the anticontractile effects of PVAT in both species. Exogenous l-cysteine, substrate for the endogenous production of H(2)S, induced vasorelaxation only at concentrations >5 mmol/l, an effect unchanged by CSE inhibition. CONCLUSIONS/SIGNFICANCE: Our results demonstrate potent vasorelaxant effects of H(2)S donors in large arteries of both rats and mice, in which XE991-sensitive KCNQ-type channel opening play a pivotal role. CSE-H(2)S seems to modulate the effect of adipocyte-derived relaxing factor in rat but not in mouse aorta. The present study provides novel insight into the interaction of CSE-H(2)S and perivascular adipose tissue. Furthermore, with additional technical advances, a future clinical approach targeting vascular H(2)S/KCNQ pathways to influence states of vascular dysfunction may be possible.

Pregabalin Attenuates Docetaxel-induced Neuropathy in Rats

Journal of Huazhong University of Science and Technology. Medical Sciences = Hua Zhong Ke Ji Da Xue Xue Bao. Yi Xue Ying De Wen Ban = Huazhong Keji Daxue Xuebao. Yixue Yingdewen Ban. Aug, 2012  |  Pubmed ID: 22886975

Chemotherapy-induced neuropathy is a serious clinical problem for patients receiving cancer treatment. The aim of this study was to investigate the potential efficacy of pregabalin in chemotherapy-induced neuropathy in rats. A total of 35 male Sprague-Dawley rats were randomly divided into 5 groups: group 1, naive control; group 2, treated with pregabalin (30 mg/kg p.o., for 8 days); group 3, docetaxel was given by single intravenous infusion at 10 mg/kg; groups 4 and 5, pregabalin at 10 mg/kg and 30 mg/kg respectively was orally administered for 8 days after the docetaxel treatment. On day 8, behavioral test was performed, and substance P and CGRP release in dorsal root ganglion (DRG) and sciatic nerve were analyzed by electron microscope. Our results showed that docetaxel induced mechanical allodynia, mechanical hyperalgesia, heat hypoalgesia, cold allodynia, and sciatic nerve impairment and substance P and CGRP release in DRG. However, oral administration of pregabalin (10 mg/kg and 30 mg/kg) for 8 consecutive days significantly attenuated docetaxel-induced neuropathy by ameliorating heat hypoalgesia, cold allodynia, impairment of sciatic nerve and reducing the release of substance P and CGRP. The findings in the present study reveal that pregabalin may be a potential treatment agent against chemotherapy-induced neuropathy.

Whirl Sign in Small Bowel Volvulus

BMJ Case Reports. 2012  |  Pubmed ID: 22891028

Allopurinol-induced Drug Rash with Eosinophilia and Systemic Symptoms Mimicking Acute Generalized Exanthematous Pustulosis

The Journal of Dermatology. Dec, 2012  |  Pubmed ID: 22901319

High-yield Chemical Vapor Deposition Growth of High-quality Large-area AB-stacked Bilayer Graphene

ACS Nano. Sep, 2012  |  Pubmed ID: 22906199

Bernal-stacked (AB-stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electric field. Mechanical exfoliation can be used to produce AB-stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB- and randomly stacked structures. Herein we report a rational approach to produce large-area high-quality AB-stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H(2)/CH(4) ratio in a low-pressure CVD process to enable the continued growth of bilayer graphene. A high-temperature and low-pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90%) and high coverage (up to 99%). The electrical transport studies demonstrate that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB-stacked bilayer graphene with the highest carrier mobility exceeding 4000 cm(2)/V · s at room temperature, comparable to that of the exfoliated bilayer graphene.

Role of TRPM2 in H(2)O(2)-induced Cell Apoptosis in Endothelial Cells

PloS One. 2012  |  Pubmed ID: 22916222

Melastatin-like transient receptor potential channel 2 (TRPM2) is an oxidant-sensitive and cationic non-selective channel that is expressed in mammalian vascular endothelium. Here we investigated the functional role of TRPM2 channels in hydrogen peroxide (H(2)O(2))-induced cytosolic Ca(2+) ([Ca(2+)](i)) elavation, whole-cell current increase, and apoptotic cell death in murine heart microvessel endothelial cell line H5V. A TRPM2 blocking antibody (TM2E3), which targets the E3 region near the ion permeation pore of TRPM2, was developed. Treatment of H5V cells with TM2E3 reduced the [Ca(2+)](i) rise and whole-cell current change in response to H(2)O(2). Suppressing TRPM2 expression using TRPM2-specific short hairpin RNA (shRNA) had similar inhibitory effect. H(2)O(2)-induced apoptotic cell death in H5V cells was examined using MTT assay, DNA ladder formation analysis, and DAPI-based nuclear DNA condensation assay. Based on these assays, TM2E3 and TRPM2-specific shRNA both showed protective effect against H(2)O(2)-induced apoptotic cell death. TM2E3 and TRPM2-specific shRNA also protect the cells from tumor necrosis factor (TNF)-α-induced cell death in MTT assay. In contrast, overexpression of TRPM2 in H5V cells resulted in an increased response in [Ca(2+)](i) and whole-cell currents to H(2)O(2). TRPM2 overexpression also aggravated the H(2)O(2)-induced apoptotic cell death. Downstream pathways following TRPM2 activation was examined. Results showed that TRPM2 activity stimulated caspase-8, caspase-9 and caspase-3. These findings strongly suggest that TRPM2 channel mediates cellular Ca(2+) overload in response to H(2)O(2) and contribute to oxidant-induced apoptotic cell death in vascular endothelial cells. Down-regulating endogenous TRPM2 could be a means to protect the vascular endothelial cells from apoptotic cell death.

Graphene: an Emerging Electronic Material

Advanced Materials (Deerfield Beach, Fla.). Nov, 2012  |  Pubmed ID: 22930422

Graphene, a single layer of carbon atoms in a honeycomb lattice, offers a number of fundamentally superior qualities that make it a promising material for a wide range of applications, particularly in electronic devices. Its unique form factor and exceptional physical properties have the potential to enable an entirely new generation of technologies beyond the limits of conventional materials. The extraordinarily high carrier mobility and saturation velocity can enable a fast switching speed for radio-frequency analog circuits. Unadulterated graphene is a semi-metal, incapable of a true off-state, which typically precludes its applications in digital logic electronics without bandgap engineering. The versatility of graphene-based devices goes beyond conventional transistor circuits and includes flexible and transparent electronics, optoelectronics, sensors, electromechanical systems, and energy technologies. Many challenges remain before this relatively new material becomes commercially viable, but laboratory prototypes have already shown the numerous advantages and novel functionality that graphene provides.

[Abnormal Findings During Newborn Period of 160 Patients with Early-onset Methylmalonic Aciduria]

Zhonghua Er Ke Za Zhi. Chinese Journal of Pediatrics. Jun, 2012  |  Pubmed ID: 22931934

Methylmalonic aciduria is the most common disorder of organic acidurias in the mainland of China. It is also the one of treatable metabolic disorders. The clinical spectrum of the patients varies from severe neonatal-onset forms with neonatal brain injury and high mortality to milder forms with adult-onset. The clinical manifestations of neonates with methylmalonic aciduria are non-specific. Early diagnosis and adequate treatment contribute a lot to improving the prognosis of the patients. In this study, the abnormal clinical and laboratory findings in neonatal period of 160 Chinese patients with early-onset methylmalonic aciduria were investigated.

Radial Probe Endobronchial Ultrasound Scanning Assessing Invasive Depth of Central Lesions in Tracheobronchial Wall

Chinese Medical Journal. Sep, 2012  |  Pubmed ID: 22932171

Patients with central tracheobronchial benign or malignant lesions who have not recieved surgical treatment can be treated by interventional techniques, such as laser, afterloading radiotherapy, cryotherapy, photodynamics treatment, radiofrequency ablation and stenting, etc. The accuracy of the invasive depth of central lesion in tracheobronchial wall plays an important role in making interventional treatment plan. This study used radial probe endobronchial ultrasound (RP-EBUS) scanning to evaluate the accuracy of the invasive depth of central lesions in tracheobronchial wall, and the influence of RP-EBUS scanning in treatment plan making and guidance.

PPARδ Activation Protects Endothelial Function in Diabetic Mice

Diabetes. Dec, 2012  |  Pubmed ID: 22933110

Recent evidence highlights the therapeutic potential of peroxisome proliferator-activated receptor-δ (PPARδ) agonists to increase insulin sensitivity in diabetes. However, the role of PPARδ in regulating vascular function is incompletely characterized. We investigate whether PPARδ activation improves endothelial function in diabetic and obese mice. PPARδ knockout (KO) and wild-type (WT) mice fed with high-fat diet and db/db mice were used as diabetic mouse models, compared with PPARδ KO and WT mice on normal diet and db/m(+) mice. Endothelium-dependent relaxation (EDR) was measured by wire myograph. Flow-mediated vasodilatation (FMD) was measured by pressure myograph. Nitric oxide (NO) production was examined in primary endothelial cells from mouse aortae. PPARδ agonist GW1516 restored EDRs in mouse aortae under high-glucose conditions or in db/db mouse aortae ex vivo. After oral treatment with GW1516, EDRs in aortae and FMDs in mesenteric resistance arteries were improved in obese mice in a PPARδ-specific manner. The effects of GW1516 on endothelial function were mediated through phosphatidylinositol 3-kinase (PI3K) and Akt with a subsequent increase of endothelial nitric oxide synthase (eNOS) activity and NO production. The current study demonstrates an endothelial-protective effect of PPARδ agonists in diabetic mice through PI3K/Akt/eNOS signaling, suggesting the therapeutic potential of PPARδ agonists for diabetic vasculopathy.

IPP5, a Novel Inhibitor of Protein Phosphatase 1, Suppresses Tumor Growth and Progression of Cervical Carcinoma Cells by Inducing G2/M Arrest

Cancer Genetics. Sep, 2012  |  Pubmed ID: 22939397

Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression and cell cycle progression. Here, we report the characterization of a novel human bone marrow stromal cell (BMSC)-derived protein called protein phosphatase 1 inhibitor 5 (IPP5), which was obtained by large-scale random sequencing of a human BMSC cDNA library. The human IPP5 cDNA encodes a protein of 116 amino acid residues, which shares high homology with human protein phosphatase 1 inhibitor-1 (PPI-1). The effect of IPP5 on tumor growth and the underlying molecular mechanisms were investigated by overexpression of IPP5 in HeLa cells, a human cervical carcinoma cell line. Our results demonstrated that overexpression of the active mutant IPP5 inhibited the growth of HeLa cells both in vitro and in vivo. Biochemical analysis demonstrated that active mutant IPP5-mediated G2/M arrest of HeLa cells involved regulation of cyclin A1, cyclin B1, CDK1, p21, and p53, as well as increased inhibition of ERK activation. Furthermore, overexpression of the active mutant IPP5 leads to the formation of dikaryons following the failure of cytokinesis. Therefore, IPP5 might be a potential growth inhibitor for human tumor cells, especially for cervical carcinoma cells, and it could contribute to the development of new therapeutic strategies for human cervical cancer treatment.

Expression of the CXCL12/CXCR4 and CXCL16/CXCR6 Axes in Cervical Intraepithelial Neoplasia and Cervical Cancer

Chinese Journal of Cancer. Sep, 2012  |  Pubmed ID: 22958742

The chemokine CXC12 is highly expressed in gynecological tumors and is widely known to play a biologically relevant role in tumor growth and spread. Recent evidence suggests that CXC16, a novel chemokine, is overexpressed in inflammation-associated tumors and mediates pro-tumorigenic effects of inflammation in prostate cancer. We therefore analyzed the expression of CXCL12 and CXCL16 and their respective receptors CXCR4 and CXCR6 in cervical intraepithelial neoplasia (CIN) and cervical cancer and further assessed their correlation with clinicopathologic features and outcomes. Tissue chip technology and immunohistochemistry were used to analyze the expression of CXCL12, CXCR4, CXCL16 and CXCR6 in healthy cervical tissue (21 cases), cervical intraepithelial neoplasia (CIN) (65 cases), and cervical carcinoma (60 cases). The correlation of protein expression with clinicopathologic features and overall survival was analyzed. These four proteins were clearly detected in membrane and cytoplasm of neoplastic epithelial cells, and their distribution and intensity of expression increased as the neoplastic lesions progressed through CIN1, CIN2, and CIN3 to invasive cancer. Furthermore, the expression of CXCR4 correlated significantly with the histological grade of cervical carcinoma, whereas the expression of CXCR6 was associated significantly with lymph node metastasis. In Kaplan-Meier analysis, patients with high CXCR6 expression had significantly lower overall survival than did those with low CXCR6 expression. The elevated co-expression levels of CXCL12/CXCR4 and CXCL16/CXCR6 in CIN and cervical carcinoma suggest a durative process in cervical carcinoma evolution. Moreover, CXCR6 may prove useful as a biomarker and a valuable prognostic factor for cervical cancer.

Complete Genome Sequence of Avian Tembusu-Related Virus Strain WR Isolated from White Kaiya Ducks in Fujian, China

Journal of Virology. Oct, 2012  |  Pubmed ID: 22966199

Avian tembusu-related virus, which was first identified in China, is an emerging virus causing serious economic loss to the Chinese poultry industry. We report here the complete genome sequences of avian tembusu-related virus strain WR, isolated from a White Kaiya duck with disease characterized by an abrupt decrease in egg laying with ovarian hemorrhage, which will help in further understanding the molecular and evolutionary characteristics and pathogenesis of avian tembusu-related virus, the new flavivirus affecting ducks in Southern China.

Genome-wide Association Studies Identify Heavy Metal ATPase3 As the Primary Determinant of Natural Variation in Leaf Cadmium in Arabidopsis Thaliana

PLoS Genetics. Sep, 2012  |  Pubmed ID: 22969436

Understanding the mechanism of cadmium (Cd) accumulation in plants is important to help reduce its potential toxicity to both plants and humans through dietary and environmental exposure. Here, we report on a study to uncover the genetic basis underlying natural variation in Cd accumulation in a world-wide collection of 349 wild collected Arabidopsis thaliana accessions. We identified a 4-fold variation (0.5-2 µg Cd g(-1) dry weight) in leaf Cd accumulation when these accessions were grown in a controlled common garden. By combining genome-wide association mapping, linkage mapping in an experimental F2 population, and transgenic complementation, we reveal that HMA3 is the sole major locus responsible for the variation in leaf Cd accumulation we observe in this diverse population of A. thaliana accessions. Analysis of the predicted amino acid sequence of HMA3 from 149 A. thaliana accessions reveals the existence of 10 major natural protein haplotypes. Association of these haplotypes with leaf Cd accumulation and genetics complementation experiments indicate that 5 of these haplotypes are active and 5 are inactive, and that elevated leaf Cd accumulation is associated with the reduced function of HMA3 caused by a nonsense mutation and polymorphisms that change two specific amino acids.

Continuous Passive Oxygen Insufflation for Out-of-hospital Cardiac Arrest: A Systemic Review of Clinical Studies

Resuscitation. Sep, 2012  |  Pubmed ID: 22986062

Synthesis of Bimetallic Pt-Pd Core-shell Nanocrystals and Their High Electrocatalytic Activity Modulated by Pd Shell Thickness

Nanoscale. Feb, 2012  |  Pubmed ID: 22159178

Bimetallic Pt-Pd core-shell nanocrystals (NCs) are synthesized through a two-step process with controlled Pd thickness from sub-monolayer to multiple atomic layers. The oxygen reduction reaction (ORR) catalytic activity and methanol oxidation reactivity of the core-shell NCs for fuel cell applications in alkaline solution are systematically studied and compared based on different Pd thickness. It is found that the Pd shell helps to reduce the over-potential of ORR by up to 50mV when compared to commercial Pd black, while generating up to 3-fold higher kinetic current density. The carbon monoxide poisoning test shows that the bimetallic NCs are more resistant to the CO poisoning than Pt NCs and Pt black. It is also demonstrated that the bimetallic Pt-Pd core-shell NCs can enhance the current density of the methanol oxidation reaction, lowering the over-potential by 35 mV with respect to the Pt core NCs. Further investigation reveals that the Pd/Pt ratio of 1/3, which corresponds to nearly monolayer Pd deposition on Pt core NCs, gives the highest oxidation current density and lowest over-potential. This study shows for the first time the systematic investigation of effects of Pd atomic shells on Pt-Pd bimetallic nanocatalysts, providing valuable guidelines for designing high-performance catalysts for fuel cell applications.

Bone Morphogenic Protein-4 Induces Endothelial Cell Apoptosis Through Oxidative Stress-dependent P38MAPK and JNK Pathway

Journal of Molecular and Cellular Cardiology. Jan, 2012  |  Pubmed ID: 22064324

The expression of bone morphogenic protein 4 (BMP4), a new pro-inflammatory marker, is increased by disturbed flow in endothelial cells (ECs). BMP4 stimulates production of reactive oxygen species (ROS) and causes endothelial cell dysfunction. The present study examined BMP4-induced apoptosis in ECs and isolated arteries from rat, mouse, and human, and the signaling pathways mediating BMP4-induced apoptosis. Apoptosis was assessed by flow cytometry to detect Annexin-V positive cells, and terminal deoxynucleotidyl transferase dUTP nick end (TUNEL) labeling. The superoxide production was measured by dihydroethidium fluorescence. BMP4 induced EC apoptosis in human mesenteric arteries, mouse aortic endothelium, rat primary ECs, and human ECs. BMP4-induced EC apoptosis was mediated through ROS production by activation of NADPH oxidase, which led to cleaved caspase-3 expression. BMP4 also induced sequential activation of p38 MAPK and JNK which was upstream of caspase 3 activation. Knockdown of BMP receptor 1A by lentiviral shRNA or NOX4 siRNA transfection inhibited BMP4-induced ROS production, p38 and JNK phosphorylation, and caspase-3 activation in ECs. JNK siRNA inhibited BMP4-induced JNK phosphorylation and caspase-3 activation. The present study delineates that BMP4 causes EC apoptosis through activation of caspase-3 in a ROS/p38MAPK/JNK-dependent signaling cascade.

NaHS Relaxes Rat Cerebral Artery in Vitro Via Inhibition of L-type Voltage-sensitive Ca(2+) Channel

Pharmacological Research : the Official Journal of the Italian Pharmacological Society. Feb, 2012  |  Pubmed ID: 22133671

H(2)S, a gaseous signalling molecule, relaxes blood vessels partly through activation of ATP-sensitive K(+) channels. It is however unclear whether H(2)S or its donors could affect other ion transporting proteins. The present study examined the hypothesis that NaHS, a H(2)S donor inhibits voltage-sensitive Ca(2+) channels and thus relaxes vascular smooth muscle cells (VSMC) in the cerebral arteries. NaHS dilated cerebral arteries from Sprague-Dawley rats with the same potency against pre-contraction by 5-HT and 60mmol/L KCl, which were unaffected by several K(+) channel blockers, N(G)-nitro-l-arginine methyl ester or indomethacin, as assessed in wire myograph under an isometric condition. Likewise, NaHS also dilated cerebral arteries against myogenic constriction in pressurized myograph under an isobaric condition. NaHS concentration-dependently inhibited CaCl(2)-induced contraction in Ca(2+)-free, 60mM K(+)-containing Krebs solution. Patch clamp recordings showed that NaHS reduced the amplitude of l-type Ca(2+) currents in single myocytes isolated enzymatically from the cerebral artery. Calcium fluorescent imaging using fluo-4 showed a reduced [Ca(2+)](i) in 60mmol/L KCl-stimulated rat cerebral arteries in response to NaHS. H(2)S precursor l-cysteine-induced relaxation in cerebral arteries was inhibited by cystathionine γ-lyase (CSE) inhibitor dl-propargylglycine. CSE was expressed in cerebral arteries. In summary, NaHS dilates rat cerebral arteries by reducing l-type Ca(2+) currents and suppressing [Ca(2+)](i) of arterial myocyte, indicating that NaHS relaxes cerebral arteries primarily through inhibiting Ca(2+) influx via Ca(2+) channels.

High-capacity Silicon-air Battery in Alkaline Solution

ChemSusChem. Jan, 2012  |  Pubmed ID: 22144348

Elements with potential: A silicon-air battery using an alkaline solution as electrolyte is comprised of only environmentally friendly and widely available elements, including silicon, potassium, oxygen, and hydrogen. The assembled battery exhibits an average working potential between 0.9 to 1.2 V at variable discharge current densities, and high specific capacities are achieved.

Raloxifene Improves Vascular Reactivity in Pressurized Septal Coronary Arteries of Ovariectomized Hamsters Fed Cholesterol Diet

Pharmacological Research : the Official Journal of the Italian Pharmacological Society. Feb, 2012  |  Pubmed ID: 22005391

Although vascular effects of selective estrogen receptor modulators (SERMs) have been extensively examined in conduit arteries, whether SERMs could favorably modulate myogenic response in resistance arteries is unknown. The impact of raloxifene therapy and cholesterol diet on myogenic constriction during estrogen deficiency is unresolved. This study investigated changes in vascular reactivity and myogenic responses in female ovariectomized (Ovx) hamsters fed high-cholesterol diet (HCD) with and without chronic treatment of raloxifene. Functional studies were performed on hamster septal coronary arteries cannulated in a pressure myograph. Acetylcholine (ACh)-induced dilatation was reduced in arteries from cholesterol-fed Ovx hamsters, but not in those from cholesterol-fed hamsters, while pressure-induced myogenic constriction was unaffected. Chronic treatment with raloxifene restored ACh-induced dilatation in cholesterol-fed Ovx hamsters. U46619-induced constriction was increased in arteries from cholesterol-fed Ovx hamsters but not from cholesterol-fed control hamsters, which was normalized by chronic raloxifene treatment. The pressure-diameter relationship is presented as normalized diameter versus intraluminal pressure, while the effect of ACh or U46619 is expressed as percentage of tone at 80mmHg. Two-way analysis of variance (ANOVA) followed by Bonferroni post-tests were used for statistical evaluation among different treatment groups. P<0.05 was taken as statistically significant. The present results show that chronic treatment with raloxifene could benefit myogenically active coronary arteries by (i) restoring ACh-induced dilatation and (ii) reducing U46619-induced constriction without affecting pressure-induced myogenic responses in cholesterol-fed hamsters during estrogen deficiency. If such benefit can be observed in humans, raloxifene and other SERMs may be useful to preserve endothelial function and curtail vascular hypersensitivity in resistance coronary arteries in post-menopausal women with hypercholesterolemia or hyperlipidemia, a lipid condition implicated in the pathogenesis of myocardial infarction.

Epigenetic Repression of Cardiac Progenitor Gene Expression by Ezh2 is Required for Postnatal Cardiac Homeostasis

Nature Genetics. Jan, 2012  |  Pubmed ID: 22267199

Adult-onset diseases can be associated with in utero events, but mechanisms for this remain unknown. The Polycomb histone methyltransferase Ezh2 stabilizes transcription by depositing repressive marks during development that persist into adulthood, but its function in postnatal organ homeostasis is unknown. We show that Ezh2 stabilizes cardiac gene expression and prevents cardiac pathology by repressing the homeodomain transcription factor gene Six1, which functions in cardiac progenitor cells but is stably silenced upon cardiac differentiation. Deletion of Ezh2 in cardiac progenitors caused postnatal myocardial pathology and destabilized cardiac gene expression with activation of Six1-dependent skeletal muscle genes. Six1 induced cardiomyocyte hypertrophy and skeletal muscle gene expression. Furthermore, genetically reducing Six1 levels rescued the pathology of Ezh2-deficient hearts. Thus, Ezh2-mediated repression of Six1 in differentiating cardiac progenitors is essential for stable gene expression and homeostasis in the postnatal heart. Our results suggest that epigenetic dysregulation in embryonic progenitor cells is a predisposing factor for adult disease and dysregulated stress responses.

Calcitriol Protects Renovascular Function in Hypertension by Down-regulating Angiotensin II Type 1 Receptors and Reducing Oxidative Stress

European Heart Journal. Jan, 2012  |  Pubmed ID: 22267242

AimsThe present study investigated whether or not calcitriol, an active form of vitamin D, protects against renovascular dysfunction in hypertension and, if so, whether or not such protection alters the expression of key proteins involved in that dysfunction.Methods and resultsChanges in isometric tension showed that the impaired endothelium-dependent relaxations in renal arteries of hypertensive patients were enhanced by 12 h in vitro treatment with calcitriol. Dihydroethidium fluorescence revealed an elevated level of reactive oxygen species (ROS) in these arteries which was reduced by calcitriol. Immunofluorescence showed that calcitriol treatment reduced the expression of AT(1)R, NOX-2, NOX-4, and p67(phox) and increased that of superoxide dismutase (SOD)-1. Twelve-hour exposure to calcitriol prevented angiotensin (Ang) II-induced increases in ROS and the over-expression of NOX-2, NOX-4, and p67(phox) in renal arteries from normotensive patients. A specific antagonist of the human vitamin D receptor (VDR), TEI-9647, abolished these effects of calcitriol. Both in vitro exposure to and chronic in vivo administration of calcitriol enhanced relaxations to acetylcholine and abolished exaggerated endothelium-dependent contractions in renal arteries of normotensive rats pre-exposed to Ang II or harvested from spontaneously hypertensive rats (SHR). Reactive oxygen species levels and expressions of AT(1)R, NAD(P)H oxidase subunits, SOD-1, and SOD-2 in SHR arteries were normalized by the chronic treatment with calcitriol.ConclusionIn vivo and in vitro activation of VDR with calcitriol improves endothelial function by normalizing the expressions of AT(1)R and radical generating and scavenging enzymes and thus preventing ROS over-production. The present findings suggest that calcitriol is effective in preserving endothelial function in hypertension.

Optical Modulation of Guided Mode Resonance in the Waveguide Grating Structure Incorporated with Azo-doped-poly(methylmethacrylate) Cladding Layer

Optics Express. Jan, 2012  |  Pubmed ID: 22274361

Optical modulation of guided mode resonance (GMR) is demonstrated in a waveguide grating structure (WGS) which contains a disperse-red1 (DR1)-doped poly(methylmethacrylate) (PMMA) cladding layer. The resonance wavelength of a GMR mode can be tuned by pumping the cladding layer with a 442 nm wavelength laser beam, because of photoinduced refractive index change in the layer. The resonance wavelength shifts to shorter wavelength side, and the shift increases with pumping power, up to a maximum shift of 5 nm. A detector was used to monitor the intensity of the light that was reflected from the WGS at the wavelengths of the GMR peak positions, and the WGS was found to exhibit optical modulation with a shortest switching time of less than 0.3s.

DPA N-3, DPA N-6 and DHA Improve Lipoprotein Profiles and Aortic Function in Hamsters Fed a High Cholesterol Diet

Atherosclerosis. Jan, 2012  |  Pubmed ID: 22284366

The present study examined the cholesterol-lowering activity of omega-3 docosapentaenoic acid (DPA n-3), omega-6 docosapentaenoic acid (DPA n-6) and docosahexaenoic acid (DHA), and their interaction with gene expression of transporters, receptors and enzymes involved in cholesterol absorption and metabolism as well as their effect on aortic function. Forty hamsters were fed either the control diet containing 0.4% stearic acid or one of the three experimental diets containing 0.4% DPA n-3, 0.4% DPA n-6 and 0.4% DHA. Results showed that supplementation of these three fatty acids reduced plasma total cholesterol (TC) and non high-density-lipoprotein cholesterol (non-HDL-C) by 29-33% and 29-50%, respectively, compared with the control. The reduction in TC and non-HDL-C was accompanied by down-regulation of hepatic SREBP-2 and HMG-CoA reductase. Aorta from DPA n-3 and DHA groups was found to have significantly lesser tension and relax better than that from the control and DPA n-6 hamsters, largely mediated by their inhibition on the gene expression of cycloxygense-2 (COX-2). It was concluded that all three fatty acids were beneficial in improving lipoprotein profile with DPA n-3 and DHA having better effect on aortic function.

Angiotensin-(1-7) Attenuates High Glucose-induced Proximal Tubular Epithelial-to-mesenchymal Transition Via Inhibiting ERK1/2 and P38 Phosphorylation

Life Sciences. Jan, 2012  |  Pubmed ID: 22285598

AIMS: The kidney is an important target for both Angiotensin II and angiotensin-(1-7) [Ang-(1-7)] in the renin-angiotensin system. However, the renal function of Ang-(1-7) remains unclear. This study is aimed at investigating the effect of Ang-(1-7) on high glucose-induced epithelial to mesenchymal transition (EMT) in cultured renal epithelial cells. MAIN METHODS: Cultured renal epithelial (NRK-52E) cell line was used in the experiment. Fluorescence immunocytochemistry was performed to observe α-smooth muscle actin (α-SMA). Real-time PCR and Western blot were used to determine mRNA and protein levels. Enzyme-linked immunosorbent assay was used to measure the concentration of transforming growth factor-β1 (TGF-β1) in the culture media. KEY FINDINGS: High glucose-induced decreased in both angiotensin-converting enzyme-related carboxypeptidase (ACE2) and Mas mRNA levels. Meanwhile, high glucose induced increases in α-SMA and vimentin, decreases in E-cadherin, elevations in TGF-β1 and fibronectin secretions. Ang-(1-7) partially reversed high glucose-induced changes in α-SMA, vimentin, E-cadherin, TGF-β1 and fibronectin. High glucose stimulated ERK, p38 and JNK phosphorylation and Ang-(1-7) reversed the changes in ERK and p38 but not JNK phosphorylation. SIGNIFICANCE: Inhibition and insufficiency in ACE2-Ang-(1-7)-Mas axis under high glucose condition participate EMT. Supplementation of Ang-(1-7) attenuates high glucose-induced EMT. ERK and p38 intracellular signaling pathways, not JNK, mediate the effect of Ang-(1-7) on EMT.

Colloidal Photonic Crystals with Narrow Stopbands Assembled from Low-adhesive Superhydrophobic Substrates

Journal of the American Chemical Society. Oct, 2012  |  Pubmed ID: 23006005

This article presents a facile approach to centimeter-scale colloidal photonic crystals (PCs) with narrow stopbands assembled on low-adhesive superhydrophobic substrates. The full-width-at-half-maxima of the stopbands are just 12 nm. The narrow stopbands of colloidal PCs are ascribed to the combined effects of perfectly ordered assembly structure, large-scale crack elimination, decreased void fraction, and sufficient thickness of the colloidal PCs. These properties result from a self-assembly process on a low-adhesive superhydrophobic substrate. Latex suspension on this substrate displays a receding three-phase contact line during evaporation, which releases tensile stress induced by latex shrinkage and results in complete elimination of cracks in the colloidal PCs. Furthermore, the simultaneous assembly of latex particles on the outermost layer of a spread liquid film contributes to the perfectly ordered assembly structure. This facile fabrication of centimeter-scale colloidal PCs with narrow stopbands will offer significant insights into the design and creation of novel optical devices.

Dietary Calcium Decreases Plasma Cholesterol Level Only in Female but Not in Male Hamster Fed a High Cholesterol Diet

Biomedical and Environmental Sciences : BES. Aug, 2012  |  Pubmed ID: 23026518

To investigate the effect of dietary calcium on plasma lipoprotein profile in castrated and ovariectomized hamsters.

First-Principles Study Toward CO Adsorption on Au/Ni Surface Alloys

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry. Dec, 2012  |  Pubmed ID: 23047643

The introduction of a second metal, gold, into a nickel matrix can effectively improve the catalytic performance and thermal stability of the catalysts toward steam reforming of methane. To investigate the effect of Au on the adsorption properties and electronic structure of the Ni(111) surface, we chose CO as a probe molecule and examined CO adsorption on various Au/Ni surfaces. It was revealed that Au addition weakened the absorbate-substrate interactions on the Ni(111) surface. With increasing gold concentration, the binding energy declines further. The variation of the binding energies has been interpreted by exploring the electronic structure of surface nickel atoms. The effect of gold can be quantitatively characterized by the slopes of the fitting equations between the binding energy and the number of gold atoms surrounding the adsorption site. Our results show that the binding energy at top sites can be approximately estimated by counting the number of surrounding gold atoms. On one specific surface, the relative magnitude of the binding energy can be simply judged by the distance between gold and the geometrical center of the adsorption site. This empirical rule holds true for C, H, and O adsorption on the Au/Ni surface. It may be applicable to a system in which a doped atom of larger atomic size is incorporated into the host metal surface by forming a surface alloy.

Cajaninstilbene Acid Relaxes Rat Renal Arteries: Roles of Ca(2+) Antagonism and Protein Kinase C-dependent Mechanism

PloS One. 2012  |  Pubmed ID: 23056567

Cajaninstilbene acid (CSA) is a major active component present in the leaves of Cajanus cajan (L.) Millsp. The present study explores the underlying cellular mechanisms for CSA-induced relaxation in rat renal arteries. Vascular reactivity was examined in arterial rings that were suspended in a Multi Myograph System and the expression of signaling proteins was assessed by Western blotting method. CSA (0.1-10 µM) produced relaxations in rings pre-contracted by phenylephrine, serotonin, 9, 11-dideoxy-9α, 11α-epoxymethanoprostaglandin F(2α) (U46619), and 60 mM KCl. CSA-induced relaxations did not show difference between genders and were unaffected by endothelium denudation, nor by treatment with N(G)-nitro-L-arginine methyl ester, indomethacin, ICI-182780, tetraethylammonium ion, BaCl(2), glibenclamide, 4-aminopyridine or propranolol. CSA reduced contraction induced by CaCl(2) (0.01-5 mM) in Ca(2+)-free 60 mM KCl solution and by 30 nM (-)-Bay K8644 in 15 mM KCl solution. CSA inhibited 60 mM KCl-induced Ca(2+) influx in smooth muscle of renal arteries. In addition, CSA inhibited contraction evoked by phorbol 12-myristate 13-acetate (PMA, protein kinase C agonist) in Ca(2+)-free Krebs solution. Moreover, CSA reduced the U46619- and PMA-induced phosphorylation of myosin light chain (MLC) at Ser19 and myosin phosphatase target subunit 1 (MYPT1) at Thr853 which was associated with vasoconstriction. CSA also lowered the phosphorylation of protein kinase C (PKCδ) at Thr505. In summary, the present results suggest that CSA relaxes renal arteries in vitro via multiple cellular mechanisms involving partial inhibition of calcium entry via nifedipine-sensitive calcium channels, protein kinase C and Rho kinase.

Inactivation of the E-Prostanoid 3 Receptor Attenuates the Angiotensin II Pressor Response Via Decreasing Arterial Contractility

Arteriosclerosis, Thrombosis, and Vascular Biology. Dec, 2012  |  Pubmed ID: 23065824

The present studies aimed at elucidating the role of prostaglandin E(2) receptor subtype 3 (E-prostanoid [EP] 3) in regulating blood pressure.

Biomolecular Specificity Controlled Nanomaterial Synthesis

Chemical Society Reviews. Oct, 2012  |  Pubmed ID: 23079759

Biomolecules capable of fabricating complex nanomaterials with required functions in nature have been exploited to artificially control nanomaterial synthesis in all aspects. This tutorial review provides an overview of recent efforts in biomimetic synthesis and the relevant mechanistic studies on biomolecular specificities toward material surfaces. It starts with a discussion of the state-of-the-art progress in colloidal nanocrystal synthesis, wherein the importance of the interfacial control over nanoscale building blocks discloses the potential of exploiting biomolecular recognition properties in nanostructure synthesis. Continued discussions will review the progress in biomimetic syntheses of different classes of nanoscale materials. In vitro biomimetic syntheses with both biomolecules isolated from organisms and material-specific peptide sequences selected from combinatorial molecular evolution processes will be demonstrated. The final part of the review presents the recent research efforts and advances in understanding biomolecule-inorganic material interactions. It is believed that with continued experimental efforts and fundamental understanding of biomolecule-material interactions scientists can one day harvest the ability to rationally design molecules to produce intricate material structures with a similar level of sophistication, precision, and superior functions as those found in nature.

The Enhanced Processing of Visual Novel Events in Females: ERP Correlates from Two Modified Three-stimulus Oddball Tasks

Brain Research. Feb, 2012  |  Pubmed ID: 22230670

The ability to detect and cope with unpredictable novel events is fundamental for adapting to a rapidly changing environment and ensuring the survival of the organism. Despite knowledge of gender differences in emotional processing, little is currently known about the impact of gender on neural processing of emotion-irrelevant, novel stimuli. Using two modified three-stimulus oddball tasks and event-related potentials (ERPs), the present study investigated the impact of sex on brain processing of novel events and the associated neurophysiological correlates. With novel and non-novel control stimuli used as task-irrelevant distracters, Experiment 1 showed higher novelty rating scores and larger size of novelty effects in brain potentials at 200-300ms and 300-430ms time intervals in females compared to males. After excluding the contribution of stimulus probability, Experiment 2 continued to display significant novelty effects in the response times and the amplitudes of the 130-500ms time windows. Most importantly, females displayed a sustained novelty effect in the late positive component (LPC) amplitudes of the 500-600ms interval, which was not observed in males. Therefore, Experiment 1 and 2 demonstrated that females are equipped with enhanced brain processing of emotion-irrelevant, novel stimuli. This phenomenon is independent of the established gender difference in infrequent stimulus processing. We suggest that our findings reflect the differential adaptive demands on females and males during evolution.

Genome-wide Patterns of Genetic Variation in Worldwide Arabidopsis Thaliana Accessions from the RegMap Panel

Nature Genetics. 2012  |  Pubmed ID: 22231484

Arabidopsis thaliana is native to Eurasia and is naturalized across the world. Its ability to be easily propagated and its high phenotypic variability make it an ideal model system for functional, ecological and evolutionary genetics. To date, analyses of the natural genetic variation of A. thaliana have involved small numbers of individual plants or genetic markers. Here we genotype 1,307 worldwide accessions, including several regional samples, using a 250K SNP chip. This allowed us to produce a high-resolution description of the global pattern of genetic variation. We applied three complementary selection tests and identified new targets of selection. Further, we characterized the pattern of historical recombination in A. thaliana and observed an enrichment of hotspots in its intergenic regions and repetitive DNA, which is consistent with the pattern that is observed for humans but which is strikingly different from that observed in other plant species. We have made the seeds we used to produce this Regional Mapping (RegMap) panel publicly available. This panel comprises one of the largest genomic mapping resources currently available for global natural isolates of a non-human species.

Clinical Study in Chinese Patients with Late-infantile Form Neuronal Ceroid Lipofuscinoses

Brain & Development. Jan, 2012  |  Pubmed ID: 22245569

Clinical findings, pathological features and tripeptidyl peptidase 1 (TPP1) activity and genetic mutation analysis data of nine patients affected with the late-infantile form of neuronal ceroid lipofuscinoses (LINCL) in China are systematically reviewed with long-term follow-up. The patients were enrolled if curvilinear bodies were found on lymphocyte, skin or muscle specimens' examination, and/or reduction of tripeptidyl peptidase 1 (TPP1) activity were detected. CLN2 gene mutation were tested in five patients. The patients have onset age of 2-3.5years, and most of them initially present partial seizure, and then progressed to deteriorated mental function, refractory myoclonic seizures, impaired vision, and ataxia with cerebellar atrophy. Discrete small vacuolated lymphocytes are found in 5-10% lymphocytes in 5 patients examined. Curvilinear bodies were found in vacuolated lymphocytes, in skin and muscle tissues. Tripeptidyl peptidase 1 (TPP1) activities are reduced in 5 patients with different CLN2 gene mutation. Detection of vacuolated lymphocytes may be a screen method for LINCL, ultrastructural examination of lymphocytes, combined with TPP1 activity assay, allowing for a definite and faster diagnosis and classification with minimal invasion.

Blueberry Extract Prolongs Lifespan of Drosophila Melanogaster

Experimental Gerontology. Feb, 2012  |  Pubmed ID: 22197903

Blueberry possesses greater antioxidant capacity than most other fruits and vegetables. The present study investigated the lifespan-prolonging activity of blueberry extracts in fruit flies and explored its underlying mechanism. Results revealed that blueberry extracts at 5mg/ml in diet could significantly extend the mean lifespan of fruit flies by 10%, accompanied by up-regulating gene expression of superoxide dismutase (SOD), catalase (CAT) and Rpn11 and down-regulating Methuselah (MTH) gene. Intensive H(2)O(2) and Paraquat challenge tests showed that lifespan was only extended in Oregon-R wild type flies but not in SOD(n108) or Cat(n1) mutant strains. Chronic Paraquat exposure shortened the maximum survival time from 73 to 35days and decreased the climbing ability by 60% while blueberry extracts at 5mg/ml in diet could significantly increase the survival rate and partially restore the climbing ability with up-regulating SOD, CAT, and Rpn11. Furthermore, gustatory assay demonstrated that those changes were not due to the variation of food intake between the control and the experimental diet containing 5mg/ml blueberry extracts. It was therefore concluded that the lifespan-prolonging activity of blueberry extracts was at least partially associated with its interactions with MTH, Rpn11, and endogenous antioxidant enzymes SOD and CAT.

HuR-mediated Posttranscriptional Regulation of P21 is Involved in the Effect of Glycyrrhiza Uralensis Licorice Aqueous Extract on Polyamine-depleted Intestinal Crypt Cells Proliferation

The Journal of Nutritional Biochemistry. Jan, 2012  |  Pubmed ID: 22217517

Glycyrrhiza uralensis licorice has long been used worldwide as a food additive and herbal medicine. It possesses a remarkable healing action on gastrointestinal ulcers. The present study was carried out to assess the effect of licorice on intestinal crypt cell proliferation and to investigate the corresponding molecular mechanism. Considering the role of crypt stem cells in intestinal mucosa repair, a well-established cytostatic cellular model, polyamine-depleted IEC-6 cells, was utilized to evaluate the effect of aqueous licorice on the proliferation of intestinal crypt cells. The growth inhibition of IEC-6 cells caused by alpha-difluoromethylornithine could be significantly reversed by concomitant treatment with 40 μg/ml and 80 μg/ml licorice aqueous extract. In particular, the restoration of cell cycle progression was accompanied by a decrease in p21 mRNA level and cytoplasmic accumulation of the RNA-binding protein HuR, which was shown to be involved in the destabilization of p21 mRNA. Using a biotin pull-down assay and a luciferase assay, it was found that licorice-modulated p21 mRNA expression was achieved by HuR-targeted AU-rich and U-rich elements that resided in the 3' untranslated region of p21 mRNA. These results demonstrate that licorice can exert its action on stimulating the growth of intestinal crypt cells by regulating p21 mRNA level at the posttranscriptional level by HuR.

Spatiotemporal Regulation of an Hcn4 Enhancer Defines a Role for Mef2c and HDACs in Cardiac Electrical Patterning

Developmental Biology. Jan, 2013  |  Pubmed ID: 23085412

Regional differences in cardiomyocyte automaticity permit the sinoatrial node (SAN) to function as the leading cardiac pacemaker and the atrioventricular (AV) junction as a subsidiary pacemaker. The regulatory mechanisms controlling the distribution of automaticity within the heart are not understood. To understand regional variation in cardiac automaticity, we carried out an in vivo analysis of cis-regulatory elements that control expression of the hyperpolarization-activated cyclic-nucleotide gated ion channel 4 (Hcn4). Using transgenic mice, we found that spatial and temporal patterning of Hcn4 expression in the AV conduction system required cis-regulatory elements with multiple conserved fragments. One highly conserved region, which contained a myocyte enhancer factor 2C (Mef2C) binding site previously described in vitro, induced reporter expression specifically in the embryonic non-chamber myocardium and the postnatal AV bundle in a Mef2c-dependent manner in vivo. Inhibition of histone deacetylase (HDAC) activity in cultured transgenic embryos showed expansion of reporter activity to working myocardium. In adult animals, hypertrophy induced by transverse aortic constriction, which causes translocation of HDACs out of the nucleus, resulted in ectopic activation of the Hcn4 enhancer in working myocardium, recapitulating pathological electrical remodeling. These findings reveal mechanisms that control the distribution of automaticity among cardiomyocytes during development and in response to stress.

Increased Expression of Activated Endothelial Nitric Oxide Synthase Contributes to Antiandrogen Resistance in Prostate Cancer Cells by Suppressing Androgen Receptor Transactivation

Cancer Letters. Jan, 2013  |  Pubmed ID: 22995070

Development of antiandrogen-resistance in advanced prostate cancer involves multiple androgen receptor (AR)-dependent and -independent pathways. Here, we demonstrated that endothelial nitric oxide synthase (eNOS) exhibited an overexpression pattern in hormone-refractory prostate cancer and several models of advanced hormone-resistant prostate cancer. We further established a novel in vitro model of antiandrogen-resistant prostate cancer (LNCaP-BC) by long-term bicalutamide treatment. Besides antiandrogen-resistant and other enhanced malignant growth phenotypes, LNCaP-BC cells exhibited an increased activated eNOS expression and NO production, and suppressed AR transactivation status. Treatment with a NOS inhibitor L-NAME could re-sensitize the growth response to bicalutamide and enhance the AR transactivation in LNCaP-BC cells. Together, our present findings indicate that increased NO production by acquired increased expression of activated eNOS could contribute to the antiandrogen-resistant growth of prostate cancer cells, via a mechanism of NO-mediated suppression of AR activity, and also targeting eNOS could be a potential therapeutic strategy for antiandrogen-resistant prostate cancer.