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Find video protocols related to scientific articles indexed in Pubmed.
Acid- and base-functionalized core-confined bottlebrush copolymer catalysts for one-pot cascade reactions.
Chem. Commun. (Camb.)
PUBLISHED: 10-16-2014
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We demonstrate a novel method that enables the formation of core-confined bottlebrush copolymers (CCBCs) as catalyst supports. Significantly, owing to the site-isolated effect, these CCBC catalysts with the incompatible acidic para-toluenesulfonic acid (PTSA) and basic 4-(dimethylamino)pyridine (DMAP) groups can conduct a simple two-step sequential reaction in one vessel.
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Effects of temperature and heat waves on emergency department visits and emergency ambulance dispatches in Pudong New Area, China: a time series analysis.
Environ Health
PUBLISHED: 09-24-2014
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In July 2013, an extended heat episode with extreme high temperature covered Pudong New Area, the largest district in Shanghai. The current study estimates the impacts of temperature and heat waves on emergency department visits (EDV) and emergency ambulance dispatches (EAD) using time-series approaches in Pudong, from 2011 to 2013.
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Self-assembly of amido-ended hyperbranched polyester films with a highly ordered dendritic structure.
ACS Appl Mater Interfaces
PUBLISHED: 08-29-2014
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Self-assemblies fabricated from dendrimers and amphiphilic polymers have demonstrated remarkable performances and a wide range of applications. Direct self-assembly of hyperbranched polymers into highly ordered macrostructures with heat-resistance remains a big challenge due to the weak amphiphilicity of the polymers. Here, we report the self-assembly of amphiphilic amido-ended hyperbranched polyester (HTDA-2) into millimeter-size dendritic films using combined hydrogen bond interaction and solvent induction. The self-assembly process and mechanism have been studied. Hydrogen bond interaction between amido-ended groups assists the aggregation of inner and outer chains of the HTDA-2, resulting in phase separation and micelle formation. Some micelles attach to and grow on the glass substrate like seedlings. Other micelles move to the seedlings and connect with their branches via solvent induction and hydrogen bond interaction, leading to the fabrication of highly ordered crystalline dendritic films that show high heat-resistance. HTDA-2 can further self-assemble into sheet crystals on the dendritic films.
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Tau overexpression impacts a neuroinflammation gene expression network perturbed in Alzheimer's disease.
PLoS ONE
PUBLISHED: 08-25-2014
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Filamentous inclusions of the microtubule-associated protein, tau, define a variety of neurodegenerative diseases known as tauopathies, including Alzheimer's disease (AD). To better understand the role of tau-mediated effects on pathophysiology and global central nervous system function, we extensively characterized gene expression, pathology and behavior of the rTg4510 mouse model, which overexpresses a mutant form of human tau that causes Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). We found that the most predominantly altered gene expression pathways in rTg4510 mice were in inflammatory processes. These results closely matched the causal immune function and microglial gene-regulatory network recently identified in AD. We identified additional gene expression changes by laser microdissecting specific regions of the hippocampus, which highlighted alterations in neuronal network activity. Expression of inflammatory genes and markers of neuronal activity changed as a function of age in rTg4510 mice and coincided with behavioral deficits. Inflammatory changes were tau-dependent, as they were reversed by suppression of the tau transgene. Our results suggest that the alterations in microglial phenotypes that appear to contribute to the pathogenesis of Alzheimer's disease may be driven by tau dysfunction, in addition to the direct effects of beta-amyloid.
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A one-pot synthetic strategy for construction of the dibenzodiazepine skeleton via a transition metal-free process.
Org. Biomol. Chem.
PUBLISHED: 07-25-2014
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A one-pot transition metal-free methodology for constructing pharmacologically active dibenzodiazepine derivatives was developed. Fluoro-, bromo- and nitro-substituted aryl aldehydes were applied to this reaction efficiently.
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Internal versus external features in triggering the brain waveforms for conjunction and feature faces in recognition.
Neuroreport
PUBLISHED: 07-09-2014
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Previous research has found that conjunction faces (whose internal features, e.g. eyes, nose, and mouth, and external features, e.g. hairstyle and ears, are from separate studied faces) and feature faces (partial features of these are studied) can produce higher false alarms than both old and new faces (i.e. those that are exactly the same as the studied faces and those that have not been previously presented) in recognition. The event-related potentials (ERPs) that relate to conjunction and feature faces at recognition, however, have not been described as yet; in addition, the contributions of different facial features toward ERPs have not been differentiated. To address these issues, the present study compared the ERPs elicited by old faces, conjunction faces (the internal and the external features were from two studied faces), old internal feature faces (whose internal features were studied), and old external feature faces (whose external features were studied) with those of new faces separately. The results showed that old faces not only elicited an early familiarity-related FN400, but a more anterior distributed late old/new effect that reflected recollection. Conjunction faces evoked similar late brain waveforms as old internal feature faces, but not to old external feature faces. These results suggest that, at recognition, old faces hold higher familiarity than compound faces in the profiles of ERPs and internal facial features are more crucial than external ones in triggering the brain waveforms that are characterized as reflecting the result of familiarity.
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Epidemiological investigation and antimicrobial susceptibility analysis of ureaplasma species and Mycoplasma hominis in outpatients with genital manifestations.
J. Clin. Pathol.
PUBLISHED: 07-02-2014
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The aim of this study was to assess the prevalence and drug resistance of Ureaplasma species and Mycoplasma hominis in outpatients with genital manifestation from 2005 to 2013 in Hangzhou, China.
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Heat wave impact on mortality in Pudong New Area, China in 2013.
Sci. Total Environ.
PUBLISHED: 06-11-2014
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In 2013 southeast China suffered from an unusual high temperature, which had broken the heat records in the past 141 years. Few studies have examined the impact of heat waves on mortality in Asia.
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Genetic regulation of mouse liver metabolite levels.
Mol. Syst. Biol.
PUBLISHED: 05-27-2014
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We profiled and analyzed 283 metabolites representing eight major classes of molecules including Lipids, Carbohydrates, Amino Acids, Peptides, Xenobiotics, Vitamins and Cofactors, Energy Metabolism, and Nucleotides in mouse liver of 104 inbred and recombinant inbred strains. We find that metabolites exhibit a wide range of variation, as has been previously observed with metabolites in blood serum. Using genome-wide association analysis, we mapped 40% of the quantified metabolites to at least one locus in the genome and for 75% of the loci mapped we identified at least one candidate gene by local expression QTL analysis of the transcripts. Moreover, we validated 2 of 3 of the significant loci examined by adenoviral overexpression of the genes in mice. In our GWAS results, we find that at significant loci the peak markers explained on average between 20 and 40% of variation in the metabolites. Moreover, 39% of loci found to be regulating liver metabolites in mice were also found in human GWAS results for serum metabolites, providing support for similarity in genetic regulation of metabolites between mice and human. We also integrated the metabolomic data with transcriptomic and clinical phenotypic data to evaluate the extent of co-variation across various biological scales.
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Hypoxia influences protein transport and epigenetic repression of CHO cell cultures in shake flasks.
Biotechnol J
PUBLISHED: 05-14-2014
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Shake flasks and bench-top bioreactors are widely used for cell culture process development, however, culture performances significantly differ between them. In order to apply the results received from small-scale cultures to production scale, it is important to understand the mechanisms underlying the differences between various culture systems. This study analyzes the expression patterns of Chinese hamster ovary (CHO) cells producing IgG-fusion protein B0 cultured in shake flasks and 5-L bench-top bioreactors by CHO-specific DNA microarrays. The data show that hypoxia was present in shake flask cultures but not in controlled, bench-top bioreactors. Hypoxic conditions appeared to be associated with epigenetic repression resulting in decreased cell culture performance and protein productivity, which is also present during large-scale bioreactor operations due to oxygen gradients. High protein productivity was associated with increased cellular machinery for protein transport and secretion in conjunction with decreased epigenetic repression in bench-top bioreactor cultivation. Metal ions could improve cell growth and protein production under hypoxia and this condition could be mimicked in small-scale bioreactors to facilitate cell culture process scale-up.
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Complete Genome Sequence of CHYJ130330, a Highly Virulent Strain of Porcine Epidemic Diarrhea Virus in South China.
Genome Announc
PUBLISHED: 04-19-2014
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Porcine epidemic diarrhea virus (PEDV) strain CHYJ130330 was isolated from southern China and shown to be highly virulent when inoculated into neonatal pigs. This report describes the complete genome sequence of CHYJ130330. These data will provide important insights into the variation of PEDV in China.
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Cloning a glutathione peroxidase gene from Nelumbo nucifera and enhanced salt tolerance by overexpressing in rice.
Mol. Biol. Rep.
PUBLISHED: 03-31-2014
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A full-length cDNA clone encoding an 866 bp-length glutathione peroxidase protein (NnGPX) was isolated from lotus (Nelumbo nucifera L.). The deduced amino acid sequence of the NnGPX gene had significant homology with ATGPX6. A 3D structural model of the NnGPX was constructed by homology modeling. The cloned NnGPX gene was expressed in Escherichia coli, and a fusion protein of about 40 kDa was detected after isopropyl thiogalactoside induction. Under different concentrations of Na2SeO3 treatments, NnGPX was found to be an enzyme that does not contain selenium. Real-time PCR analysis showed that the NnGPX gene was expressed in all organs of lotus, and its high expression mainly occurred in organs with active metabolisms. NnGPX transcript increased remarkably in response to cold, heat, mechanical damage, and salt treatment. Subsequently, the NnGPX gene was introduced in Oryza sativa cv. Yuetai B. PCR results verified the integration of this gene into the genome of rice and reverse transcription-PCR verified that this gene had been expressed in transgenic rice. The transgenic plants were significantly more tolerant to salt stress compared with the wild-type.
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Protective effect of carvacrol on acute lung injury induced by lipopolysaccharide in mice.
Inflammation
PUBLISHED: 03-01-2014
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Carvacrol, the major component of Plectranthus amboinicus, has been known to exhibit anti-inflammatory activities. The aim of this study was to investigate the effects of carvacrol on lipopolysaccharide (LPS)-induced endotoxemia and acute lung injury (ALI) in mice. Mice were injected intraperitoneally (i.p.) with LPS and the mortality of mice for 7 days were observed twice a day. Meanwhile, the protective effect of carvacrol (20, 40 or 80 mg/kg) on LPS-induced endotoxemia were detected. Using an experimental model of LPS-induced ALI, we examined the effect of carvacrol in resolving lung injury. The results showed that carvacrol could improve survival during lethal endotoxemia and attenuate LPS-induced ALI in mice. The anti-inflammatory mechanisms of carvacrol may be due to its ability to inhibit NF-?B and MAPKs signaling pathways, thereby inhibiting inflammatory cytokines TNF-?, IL-6 and IL-1? production.
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miR-22 inhibits osteosarcoma cell proliferation and migration by targeting HMGB1 and inhibiting HMGB1-mediated autophagy.
Tumour Biol.
PUBLISHED: 02-20-2014
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Acquisition of drug-resistant phenotypes is often associated with chemotherapy in osteosarcoma. Studies show that high-mobility group box 1 (HMGB1) plays an important role in facilitating autophagy and promotes drug resistance in osteosarcoma cells. In this study, we determined the targeting role of miR-22 to HMGB1 and the regulation of miR-22 on the HMGB1-mediated cell autophagy and on the cell proliferation, migration, and invasion of osteosarcoma cells. Results demonstrated that miR-22 well paired with the 3'-UTR of HMGB1 downregulated the HMGB1 expression and blocked the HMGB1-mediated autophagy during chemotherapy in osteosarcoma cells in vitro. Further study showed that the blockage of autophagy by miR-22 inhibited the osteosarcoma cell proliferation, migration, and invasion. In summary, this study implied the negative regulation of miR-22 on the HMGB1-mediated autophagy in osteosarcoma cells.
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Sox11 promotes endogenous neurogenesis and locomotor recovery in mice spinal cord injury.
Biochem. Biophys. Res. Commun.
PUBLISHED: 02-17-2014
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We introduced a lentiviral vector containing the Sox11 gene into injured spinal cords of mice to evaluate the therapeutic potential of Sox11 in spinal cord injury. Sox11 markedly improved locomotor recovery after spinal cord injury and this recovery was accompanied by an up-regulation of Nestin/Doublecortin expression in the injured spinal cord. Sox11 was mainly located in endogenous neural stem cells lining the central canal and in newly-generated neurons in the spinal cord. In addition, Sox 11 significantly induced expressions of BDNF in the spinal cords of LV-Sox11-treated mice. We concluded that Sox11 induced activation of endogenous neural stem cells into neuronal determination and migration within the injured spinal cord. The resultant increase of BDNF at the injured site might form a distinct neurogenic niche which induces a final neuronal differentiation of these neural stem cells. Enhancing Sox11 expression to induce neurogenic differentiation of endogenous neural stem cells after injury may be a promising strategy in restorative therapy after SCI in mammals.
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ERP profiles for face and word recognition are based on their status in semantic memory not their stimulus category.
Brain Res.
PUBLISHED: 02-04-2014
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Previous research has suggested that faces and words are processed and remembered differently as reflected by different ERP patterns for the two types of stimuli. Specifically, face stimuli produced greater late positive deflections for old items in anterior compared to posterior regions, while word stimuli produced greater late positive deflections in posterior compared to anterior regions. Given that words have existing representations in subjects? long-term memories (LTM) and that face stimuli used in prior experiments were of unknown individuals, we conducted an ERP study that crossed face and letter stimuli with the presence or absence of a prior (stable or existing) memory representation. During encoding, subjects judged whether stimuli were known (famous face or real word) or not known (unknown person or pseudo-word). A surprise recognition memory test required subjects to distinguish between stimuli that appeared during the encoding phase and stimuli that did not. ERP results were consistent with previous research when comparing unknown faces and words; however, the late ERP pattern for famous faces was more similar to that for words than for unknown faces. This suggests that the critical ERP difference is mediated by whether there is a prior representation in LTM, and not whether the stimulus involves letters or faces.
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Acute murine antigen-induced arthritis is not affected by disruption of osteoblastic glucocorticoid signalling.
BMC Musculoskelet Disord
PUBLISHED: 01-29-2014
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The role of endogenous glucocorticoids (GC) in the initiation and maintenance of rheumatoid arthritis (RA) remains unclear. We demonstrated previously that disruption of GC signalling in osteoblasts results in a profound attenuation of K/BxN serum-induced arthritis, a mouse model of RA. To determine whether or not the modulation of the inflammatory response by osteoblasts involves T cells, we studied the effects of disrupted osteoblastic GC-signalling in the T cell-dependent model of antigen-induced arthritis (AIA).
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Concurrent autoimmune pancreatitis and primary biliary cirrhosis: a rare case report and literature review.
BMC Gastroenterol
PUBLISHED: 01-10-2014
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Both autoimmune pancreatitis (AIP) and primary biliary cirrhosis (PBC) are related to various diseases. But the concurrence of AIP and PBC is extremely rare, with only 2 cases reported. Here we report the concurrence of AIP and PBC in a Chinese patient for the first time.
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Pretreatment with 2-(4-methoxyphenyl)ethyl-2-acetamido-2-deoxy-?-D-pyranoside attenuates cerebral ischemia/reperfusion-induced injury in vitro and in vivo.
PLoS ONE
PUBLISHED: 01-01-2014
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Salidroside, extracted from the root of Rhodiola rosea L, is known for its pharmacological properties, in particular its neuroprotective effects. 2-(4-Methoxyphenyl) ethyl-2-acetamido-2-deoxy-?-D-pyranoside (GlcNAc-Sal), an analog of salidroside, was recently synthesized and shown to possess neuroprotective properties. The purpose of the current study was to investigate the neuroprotective effects of GlcNAc-Sal against oxygen-glucose deprivation-reperfusion (OGD-R)-induced neurotoxicity in vitro and global cerebral ischemia-reperfusion (GCI-R) injury in vivo. Cell viability tests and Hoechst 33342 staining confirmed that GlcNAc-Sal pretreatment markedly attenuated OGD-R induced apoptotic cell death in immortalized mouse hippocampal HT22 cells. Western blot, immunofluorescence and PCR analyses revealed that GlcNAc-Sal pretreatment restored the balance of pro- and anti-apoptotic proteins and inhibited the activation of caspase-3 and PARP induced by OGD-R treatment. Further analyses showed that GlcNAc-Sal pretreatment antagonized reactive oxygen species (ROS) generation, iNOS-derived NO production and NO-related apoptotic cell death during OGD-R stimulation. GCI-R was induced by bilateral common carotid artery occlusion (BCCAO) and reperfusion in mice in vivo. Western blot analysis showed that GlcNAc-Sal pretreatment decreased the expression of caspase-3 and increased the expression of Bcl-2 (B-cell lymphoma 2)/Bax (Bcl-2-associated X protein) induced by GCI-R treatment. Our findings suggest that GlcNAc-Sal pretreatment prevents brain ischemia reperfusion injury by the direct or indirect suppression of cell apoptosis and GlcNAc-Sal could be developed as a broad-spectrum agent for the prevention and/or treatment of cerebral ischemic injury.
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Salt-induced changes in cardiac phosphoproteome in a rat model of chronic renal failure.
PLoS ONE
PUBLISHED: 01-01-2014
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Heart damage is widely present in patients with chronic kidney disease. Salt diet is the most important environmental factor affecting development of chronic renal failure and cardiovascular diseases. The proteins involved in chronic kidney disease -induced heart damage, especially their posttranslational modifications, remain largely unknown to date. Sprague-Dawley rats underwent 5/6 nephrectomy (chronic renal failure model) or sham operation were treated for 2 weeks with a normal-(0.4% NaCl), or high-salt (4% NaCl) diet. We employed TiO2 enrichment, iTRAQ labeling and liquid-chromatography tandem mass spectrometry strategy for phosphoproteomic profiling of left ventricular free walls in these animals. A total of 1724 unique phosphopeptides representing 2551 non-redundant phosphorylation sites corresponding to 763 phosphoproteins were identified. During normal salt feeding, 89 (54%) phosphopeptides upregulated and 76 (46%) phosphopeptides downregulated in chronic renal failure rats relative to sham rats. In chronic renal failure rats, high salt intake induced upregulation of 84 (49%) phosphopeptides and downregulation of 88 (51%) phosphopeptides. Database searches revealed that most of the identified phospholproteins were important signaling molecules such as protein kinases, receptors and phosphatases. These phospholproteins were involved in energy metabolism, cell communication, cell differentiation, cell death and other biological processes. The Search Tool for the Retrieval of Interacting Genes analysis revealed functional links among 15 significantly regulated phosphoproteins in chronic renal failure rats compared to sham group, and 23 altered phosphoproteins induced by high salt intake. The altered phosphorylation levels of two proteins involved in heart damage, lamin A and phospholamban were validated. Expression of the downstream genes of these two proteins, desmin and SERCA2a, were also analyzed.
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Distinct expression profiles of LncRNAs between brown adipose tissue and skeletal muscle.
Biochem. Biophys. Res. Commun.
PUBLISHED: 12-05-2013
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Both brown adipose tissue and skeletalmuscle have abundant mitochondria and energy consumption capacity. They are similar in origin and gain different potential of energy metabolism after differentiation and maturation. The mechanism that cause the difference is not yet fully understood. Long non-coding RNAs (lncRNAs) which comprise the bulk of the human non-coding transcriptome have been proved to play key roles in various biological processes. Whether they will have a function on the differentiation and energy metabolism between BAT and skeletalmuscle is still unknown. To identify the cellular long noncoding RNAs (lncRNAs) involved in the progress, we used the next generation transcriptome sequencing and microarray techniques, and investigated 704 up-regulated and 896 down-regulated lncRNAs (fold-change >3.0) in BAT by comparing the expression profile. Furthermore, we reported AK003288 associated with junctophilin 2 (Jph2) gene which may affect energy metabolism. This study show distinct expression profiles of LncRNAs between brown adipose tissue and skeletal muscle which provide information for further research on differentiation of adipocyte and transdifferentiation between BAT and skeletalmuscle that will be helpful to find a new therapeutic target for combatting obesity.
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Phylogeography of the Ricketts big-footed bat, Myotis pilosus (Chiroptera: Vespertilionidae): a novel pattern of genetic structure of bats in China.
BMC Evol. Biol.
PUBLISHED: 10-18-2013
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China is characterized by complex topographic structure and dramatic palaeoclimatic changes, making species biogeography studies particularly interesting. Previous researchers have also demonstrated multiple species experienced complex population histories, meanwhile multiple shelters existed in Chinese mainland. Despite this, species phylogeography is still largely unexplored. In the present study, we used a combination of microsatellites and mitochondrial DNA (mtDNA) to investigate the phylogeography of the east Asian fish-eating bat (Myotis pilosus).
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Genetic diversity of kenaf (Hibiscus cannabinus) evaluated by inter-simple sequence repeat (ISSR).
Biochem. Genet.
PUBLISHED: 06-21-2013
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Understanding genetic diversity is very useful for scientific utilization for breeding. In this study, we estimated the genetic distances in a panel of 84 kenaf accessions collected from 26 countries and regions using ISSR markers. The results of UPGMA analysis showed that kenaf germplasm had abundant genetic variation, with genetic dissimilarity coefficients ranging from 0.01 to 0.62. The in-group dissimilarity coefficient (0.29) was observed in 84 kenaf accessions, and all the accessions could be divided into three groups: cultivars (L1-1), relatively wild species (L1-2 and L1-3), and wild species (the others). Further in-group analysis in group L1-1 (0.19) revealed that the kenaf cultivars could be divided into five subgroups with distinct regional characteristics. It is imperative that genes be exchanged among all kinds of tested varieties from different origins. The results provide a useful basis for kenaf germplasm research and breeding.
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HuR is required for IL-17-induced Act1-mediated CXCL1 and CXCL5 mRNA stabilization.
J. Immunol.
PUBLISHED: 06-14-2013
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IL-17, a major inflammatory cytokine plays a critical role in the pathogenesis of many autoimmune inflammatory diseases. In this study, we report a new function of RNA-binding protein HuR in IL-17-induced Act1-mediated chemokine mRNA stabilization. HuR deficiency markedly reduced IL-17-induced chemokine expression due to increased mRNA decay. Act1-mediated HuR polyubiquitination was required for the binding of HuR to CXCL1 mRNA, leading to mRNA stabilization. Although IL-17 induced the coshift of Act1 and HuR to the polysomal fractions in a sucrose gradient, HuR deficiency reduced the ratio of translation-active/translation-inactive IL-17-induced chemokine mRNAs. Furthermore, HuR deletion in distal lung epithelium attenuated IL-17-induced neutrophilia. In summary, HuR functions to couple receptor-proximal signaling to posttranscriptional machinery, contributing to IL-17-induced inflammation.
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Sleep deprivation alters effort discounting but not delay discounting of monetary rewards.
Sleep
PUBLISHED: 06-05-2013
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To determine whether sleep deprivation would affect the discounting of delayed rewards, of rewards entailing the expense of effort, or both.
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Binding investigation on the interaction between Methylene Blue (MB)/TiO2 nanocomposites and bovine serum albumin by resonance light-scattering (RLS) technique and fluorescence spectroscopy.
J. Photochem. Photobiol. B, Biol.
PUBLISHED: 05-23-2013
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The interaction between Methylene Blue (MB)/TiO2 nanocomposites and bovine serum albumin (BSA) was investigated by resonance light scattering (RLS), fluorescence, three-dimension spectra and UV-vis absorbance spectroscopy. Several factors which may influence the RLS intensity were also investigated before characterizing MB/TiO2-BSA complex. It was proved that the mechanism of MB/TiO2 nanocomposites binding to BSA was mainly a result of the formation of MB/TiO2-BSA complex. The binding constant of MB/TiO2-BSA is 0.762 × 10(-5) L mol(-1) at 298K. By calculating the binding constant at different temperature, the thermodynamic parameters ?H, ?G, and ?S can be observed and deduced that the hydrophobic interactions played an important role to stabilize the complex. The distance r (3.73 nm) between donor (BSA) and acceptor (MB/TiO2) was obtained according to fluorescence resonance energy transfer (FRET). The binding site for MB/TiO2 on BSA was mainly located in sub-domain IIA. The UV-vis absorbance, circular dichroism and three dimension fluorescence have also been used to investigate the effect of MB/TiO2 on the conformation of BSA.
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Neuroprotective effect of 2-(4-methoxyphenyl)ethyl-2-acetamido-2-deoxy-?-D-pyranoside against sodium nitroprusside-induced neurotoxicity in HT22 cells.
Mol. Cell. Biochem.
PUBLISHED: 04-25-2013
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2-(4-Methoxyphenyl) ethyl-2-acetamido-2-deoxy-?-D-pyranoside (GlcNAc-Sal), the salidroside analog was synthesized and shown to inhibit hypoglycemia and serum limitation induced apoptosis in PC12 cells. This study investigated the protective effects of GlcNAc-Sal on sodium nitroprusside (SNP)-induced cytotoxicity in HT22 cells. Cell viability tests and Hoechst 33342 staining comfirmed that GlcNAc-Sal pretreatment attenuated SNP-stimulated apoptotic cell death in HT22 cells in a concentration-dependent manner. The measurements of reactive oxygen species (ROS), nitric oxide (NO) production and apoptosis-related gene and protein expression suggest that the protection of GlcNAc-Sal, shown in this study, might be mediated by inhibiting intracellular ROS and NO production, and regulating apoptosis-related gene and protein expression during SNP stimulation. Perhaps, this study might contribute to the development of GlcNAc-Sal as an agent for preventing and/or treating a variety of NO-induced brain diseases.
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MicroRNA changes associated with atypical CYP1A1 inducer BMS-764459.
Toxicology
PUBLISHED: 04-02-2013
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The corticotrophin releasing factor (CRF) receptor I antagonist, BMS-764459 (evaluated as a potential treatment of affective disorders), was orally dosed to female Sprague-Dawley rats once daily for 2 weeks (vehicle control or 175mg/kg/day). To investigate the mechanism of BMS-764459-related liver weight increases, total liver RNA was isolated and evaluated for mRNA gene expression by microarray analysis (assessing the expression of approximately 24,000 genes) from snap-frozen tissue. Subsequently, mRNA and miRNA (microRNA) were also analyzed 5 years later from FFPE (Formalin Fixed Paraffin Embedded) samples via RT-PCR (about 800 miRNA evaluated). Genomic analyses showed that BMS-764459 induces AhR target genes with additional inductions of CYP2B, CYP3A, and Abcc3 consistent with the gene expression pattern of atypical CYP1A1 inducers. Analysis of miRNA expression identified a number of significantly affected miRNAs. To further evaluate their role in atypical CYP1A1 induction, an in silico evaluation of differentially expressed miRNA was performed and their putative mRNA 3-UTR (untranslated region) binding sequences were evaluated. MiR-680 and miR-29a were identified as potential regulators and biomarkers of atypical CYP1A1 induction by regulating Abcc3, CYP3A and CYP2B as well as a number of AhR targeted genes.
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Active extracts of black tea (Camellia Sinensis) induce apoptosis of PC-3 prostate cancer cells via mitochondrial dysfunction.
Oncol. Rep.
PUBLISHED: 03-27-2013
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Cancer of the prostate gland is the most common invasive malignancy and the second leading cause of cancer-related death in human males. Many studies have shown that black tea reduces the risk of several types of cancer. We studied the effects of active extracts of black tea and the black tea polyphenols theaflavins (TFs), on the cellular proliferation and mitochondria of the human prostate cancer cell line PC-3. Our studies revealed that Yinghong black tea extracts (YBT), Assam black tea extracts (ABT) and TFs inhibited cell proliferation in a dose-dependent manner. We also showed that TFs, YBT and ABT affected the morphology of PC-3 cells and induced apoptosis or even necrosis in PC-3 cells. In addition, it was observed that the samples significantly caused loss of the mitochondrial membrane potential, release of cytochrome c from the intermembrane space into the cytosol, decrease of the ATP content and activation of caspase-3 compared with the control. Taken together, these findings suggest that black tea could act as an effective anti-proliferative agent in PC-3 cells, and TFs, YBT and ABT induced apoptosis of PC-3 cells through mitochondrial dysfunction.
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Development and validation of a PCR-based functional marker system for the brown planthopper resistance gene Bph14 in rice.
Breed. Sci.
PUBLISHED: 03-21-2013
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Brown planthopper (BPH) is the most damaging rice pest globally. Resistant varieties are the most effective and environmental strategy for protecting the rice crop from BPH. Functional markers (FMs) designed from polymorphic sites within gene sequences affecting phenotypic variation are highly efficient when used for marker assisted selection (MAS). Bph14 is the first and only cloned insect resistance gene so far in rice. Compared to the sequences of its non-effective alleles there are a number SNP differences. In this study, the method of allele-specific amplification (ASA) was adopted to design a simple, co-dominant, functional marker Bph14P/N for Bph14. Bph14P/N was combined with two specific dominant markers: one, named Bph14P, targets the promoter region of Bph14 and amplifies 566 bp fragments; and the other, Bph14N, targets the LRR region of bph14 and amplifies 345 bp fragments. Specificity and applicability of the functional marker system were verified in two breeding populations and a Chinese mini core collection of Oryza sativa. We recommend the use of this simple, low-cost marker system in routine genotyping for Bph14 in breeding populations.
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Asymptomatic hepatobiliary cystadenoma of the hepatic caudate lobe: a case report.
J Biomed Res
PUBLISHED: 02-08-2013
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Human hepatobiliary cystadenoma is a rare benign cystic tumor of the liver, and is extremely rare in the caudate lobe. We herein present a case of a 70-year-old male with a hepatobiliary cystadenoma originating from the caudate lobe.
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11?-hydroxysteroid dehydrogenase type 1 gene knockout attenuates atherosclerosis and in vivo foam cell formation in hyperlipidemic apoE?/? mice.
PLoS ONE
PUBLISHED: 02-01-2013
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Chronic glucocorticoid excess has been linked to increased atherosclerosis and general cardiovascular risk in humans. The enzyme 11?-hydroxysteroid dehydrogenase type 1 (11?HSD1) increases active glucocorticoid levels within tissues by catalyzing the conversion of cortisone to cortisol. Pharmacological inhibition of 11?HSD1 has been shown to reduce atherosclerosis in murine models. However, the cellular and molecular details for this effect have not been elucidated.
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Failure mode and effect analysis in blood transfusion: a proactive tool to reduce risks.
Transfusion
PUBLISHED: 01-31-2013
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The aim of blood transfusion risk management is to improve the quality of blood products and to assure patient safety. We utilize failure mode and effect analysis (FMEA), a tool employed for evaluating risks and identifying preventive measures to reduce the risks in blood transfusion.
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Nischarin is differentially expressed in rat brain and regulates neuronal migration.
PLoS ONE
PUBLISHED: 01-16-2013
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Nischarin is a protein known to inhibit breast cancer cell motility by regulating the signaling of the Rho GTPase family. However, little is known about its location and function in the nervous system. The aim of the present study was to investigate the regional and cellular expression and functions of Nischarin in the adult rodent brain. As assessed by real-time PCR, Western blot analysis and immunostaining, we found that Nischarin was widely distributed throughout the brain, with a higher expression in the cerebral cortex and hippocampus. Double-labeling showed that Nischarin was expressed in neurons and was mainly located in the perinuclear region and F-actin-rich protrusions. The expression pattern of Nischarin in the brain was thought to be closely associated with its function. This was verified by our findings from cell migration assays that Nischarin regulated neuronal migration. These results provide a preliminary survey of the distribution of Nischarin in different regions and cell types in the rat brain. This might help to elucidate its physiological roles, and to evaluate its potential clinical implications.
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Genetic control of obesity and gut microbiota composition in response to high-fat, high-sucrose diet in mice.
Cell Metab.
PUBLISHED: 01-15-2013
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Obesity is a highly heritable disease driven by complex interactions between genetic and environmental factors. Human genome-wide association studies (GWAS) have identified a number of loci contributing to obesity; however, a major limitation of these studies is the inability to assess environmental interactions common to obesity. Using a systems genetics approach, we measured obesity traits, global gene expression, and gut microbiota composition in response to a high-fat/high-sucrose (HF/HS) diet of more than 100 inbred strains of mice. Here we show that HF/HS feeding promotes robust, strain-specific changes in obesity that are not accounted for by food intake and provide evidence for a genetically determined set point for obesity. GWAS analysis identified 11 genome-wide significant loci associated with obesity traits, several of which overlap with loci identified in human studies. We also show strong relationships between genotype and gut microbiota plasticity during HF/HS feeding and identify gut microbial phylotypes associated with obesity.
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Brevity is prevalent in bat short-range communication.
J. Comp. Physiol. A Neuroethol. Sens. Neural. Behav. Physiol.
PUBLISHED: 01-05-2013
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Animal communication follows many coding schemes. Less is known about the coding strategy for signal length and rates of use in animal vocal communication. A generalized brevity (negative relation between signal length and frequency of use) is innovatively explored but remains controversial in animal vocal communication. We tested brevity for short-range social and distress sounds from four echolocating bats: adult black-bearded tomb bat Taphozous melanopogon, Mexican free-tailed bat Tadarida brasiliensis, adult greater horseshoe bat Rhinolophus ferrumequinum, and adult least horseshoe bat Rhinolophus pusillus. There was a negative association between duration and number of social but not distress calls emitted. The most frequently emitted social calls were brief, while most distress calls were long. Brevity or lengthiness was consistently selected in vocal communications for each species. Echolocating bats seem to have convergent coding strategy for communication calls. The results provide the evidence of efficient coding in bat social vocalizations, and lay the basis of future researches on the convergence for neural control on bats communication calls.
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Deletion of mesenchymal glucocorticoid receptor attenuates embryonic lung development and abdominal wall closure.
PLoS ONE
PUBLISHED: 01-01-2013
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As a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors, the glucocorticoid receptor (GR) is essential for normal embryonic development. To date, the role of mesenchymal glucocorticoid signaling during development has not been fully elucidated. In the present study, we investigated the role of the GR during embryogenesis specifically in mesenchymal tissues. To this aim, we crossed GRflox mice with Dermo1-Cre mice to generate GR(Dermo1) mice, where the GR gene was deleted within mesenchymal cells. Compared to their wild type littermates, GR(Dermo1) mice displayed severe pulmonary atelectasis, defects in abdominal wall formation resulting in intestinal herniation, abnormal extracellular matrix synthesis in connective tissues and high postnatal lethality. Lungs of GR(Dermo1) mice failed to progress from the canalicular to saccular stage, as evidenced by the presence of immature air sacs, thickened interstitial mesenchyme and an underdeveloped vascular network between E17.5 and E18.5. Furthermore, myofibroblasts and vascular smooth muscle cells, although present in normal numbers in GR(Dermo1) animals, were characterized by significantly reduced elastin synthesis, whilst epithelial lining cells of the immature saccules were poorly differentiated. A marked reduction in normal elastin and collagen deposits were also observed in connective tissues adjacent to the umbilical hernia. This study demonstrates that eliminating the GR in cells of the mesenchymal lineage results in marked effects on interstitial fibroblast function, including a significant decrease in elastin synthesis. This results in lung atelectasis and postnatal lethality, as well as additional and hitherto unrecognized developmental defects in abdominal wall formation. In addition, altered glucocorticoid signaling in the mesenchyme attenuates normal lung epithelial differentiation.
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Attenuation of glomerular filtration barrier damage in adriamycin-induced nephropathic rats with bufalin: an antiproteinuric agent.
J. Steroid Biochem. Mol. Biol.
PUBLISHED: 08-07-2011
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Proteinuria is an important risk factor for the progression and prognosis of chronic kidney disease. Bufalin, a cardiotonic steroid, has been shown to posses a variety of biological activities including cardiotonic, anaesthetic and antineoplastic activities, and regulate the immune response. This study investigated the effects of bufalin against proteinuria and glomerular filtration barrier damage in rats with adriamycin (ADR)-induced nephropathy. We compared the blood and urine biochemical indices and the histologic and ultrastructure of the glomerulus in ADR rats with and without the intervention of bufalin or prednisone. The transcription, expression and distribution of the podocyte-associated molecules were compared utilising RT-PCR, western blotting and immunohistochemical staining. We found that bufalin reduced the urinary protein excretion and optimised the lipidaemia of the ADR rats. Bufalin alleviated the removal of podocyte foot processes and attenuated the changes in nephrin, podocin and integrin-linked kinase (ILK) stainings in the glomerulus of the ADR rats. Bufalin notably decreased the expression of nephrin and ILK but inhibited the down-regulation of podocin in protein levels on the renal cortex of the ADR rats. Additionally, bufalin inhibited the up-regulation of podocin and ILK in mRNA levels but did not affect nephrin mRNA levels. These results suggest that bufalin could alleviate ADR-induced proteinuria by protecting the glomerular filtration barrier and may be a novel potential therapeutic agent for proteinuria-associated kidney disease.
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Biochemical and transcriptional profiling to triage additional activities in a series of IGF-1R/IR inhibitors.
Bioorg. Med. Chem.
PUBLISHED: 08-02-2011
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Therapeutic development of a targeted agent involves a series of decisions over additional activities that may be ignored, eliminated or pursued. This paper details the concurrent application of two methods that provide a spectrum of information about the biological activity of a compound: biochemical profiling on a large panel of kinase assays and transcriptional profiling of mRNA responses. Our mRNA profiling studies used a full dose range, identifying subsets of transcriptional responses with differing EC(50)s which may reflect distinct targets. Profiling data allowed prioritization for validation in xenograft models, generated testable hypotheses for active compounds, and informed decisions on the general utility of the series.
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A dually effective inorganic salt at inducing obvious viscoelastic behavior of both cationic and anionic surfactant solutions.
Langmuir
PUBLISHED: 07-19-2011
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Hydrazine nitrate (HN), an inorganic salt, was first found to have dual effects on inducing obvious viscoelasticity of both cationic and anionic surfactant solutions. It was interesting that the surfactant solutions exhibited characteristic wormlike micelle features with strong viscoelastic properties upon the addition of this inorganic salt. The rheological properties of the surfactant solutions have been measured and discussed. The apparent viscosity of the solutions showed a volcano change with an increase of the HN concentration. Correspondingly, the microstructures of the micelles in the solutions changed with the apparent viscosity. First, wormlike micelles began to form and grew with an increase of the HN concentration. Subsequently, the systems exhibited linear viscoelasticity with characteristics of a Maxwell fluid in the intermediate mass fraction range, which originated from a 3D entangled network of wormlike micelles. Finally, a transition from linear micelles to branched ones probably took place at higher HN contents. In addition, the origin of the dual effects brought by HN addition on inducing viscoelasticity in both cationic and anionic surfactant solutions was investigated.
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Bufalin inhibits platelet-derived growth factor-BB-induced mesangial cell proliferation through mediating cell cycle progression.
Biol. Pharm. Bull.
PUBLISHED: 07-02-2011
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Bufalin, a traditional Chinese medicine, has been reported as a protective factor in many tumors. We therefore investigated the effect of bufalin on platelet-derived growth factor (PDGF)-BB-induced proliferation of cultured rat mesangial cells. The effect of bufalin on cell proliferation and its underlying mechanisms were investigated in cultured rat mesangial cells (MCs) by the methylthiazoletetrazolium (MTT) assay, flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and cyclin-dependent kinases (CDK)2 and CDK4 kinase assays. Bufalin inhibited 20 ng/ml PDGF-BB-induced MC proliferation in a dose-dependent manner. Similar results were observed in different concentrations of bufalin, which blocked PDGF-BB-induced progression through G0/G1 to S phase of the cell cycle. Furthermore, bufalin not only inhibited upregulation of cyclin D1 and CDK4, but also downregulation of p21 in both mRNA and protein levels. Although bufalin did not affect p27 and CDK2 mRNA expression, it reversed downregulation of p27 and upregulation of CDK2 in protein level. Activity of CDK2 and CDK4 was also inhibited by bufalin. However, both bufalin and PDGF-BB did not affect cyclin E mRNA or protein expression. These results suggest that bufalin could inhibit MC proliferation by modulating cell cycle progress, indicating that bufalin could be a potential therapeutic agent for the prevention of mesangial proliferative glomerulonephritis.
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A mechanistic study on the effect of dexamethasone in moderating cell death in Chinese Hamster Ovary cell cultures.
Biotechnol. Prog.
PUBLISHED: 06-17-2011
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Dexamethasone (DEX) was previously shown (Jing et al., Biotechnol Bioeng. 2010;107:488-496) to play a dual role in increasing sialylation of recombinant glycoproteins produced by Chinese Hamster Ovary (CHO) cells. DEX addition increased sialic acid levels of a recombinant fusion protein through increased expression of ?2,3-sialyltransferase and ?1,4-galactosyltransferase, but also decreased the sialidase-mediated, extracellular degradation of sialic acid through slowing cell death at the end of the culture period. This study examines the underlying mechanism for this cytoprotective action by studying the transcriptional response of the CHO cell genome upon DEX treatment using DNA microarrays and gene ontology term analysis. Many of those genes showing a significant transcriptional response were associated with the regulation of programmed cell death. The gene with the highest change in expression level, as validated by Quantitative PCR assays with TaqMan® probes and confirmed by Western Blot analysis, was the antiapoptotic gene Tsc22d3, also referred to as GILZ (glucocorticoid-induced leucine zipper). The pathway by which DEX suppressed cell death towards the end of the culture period was also confirmed by showing involvement of glucocorticoid receptors and GILZ through studies using the glucocorticoid antagonist mifepristone (RU-486). These findings advance the understanding of the mechanism by which DEX suppresses cell death in CHO cells and provide a rationale for the application of glucocorticoids in CHO cell culture processes.
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Self-Assembled Large Au Nanoparticle Arrays with Regular Hot Spots for SERS.
Small
PUBLISHED: 04-10-2011
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The cost-effective self-assembly of 80 nm Au nanoparticles (NPs) into large-domain, hexagonally close-packed arrays for high-sensitivity and high-fidelity surface-enhanced Raman spectroscopy (SERS) is demonstrated. These arrays exhibit specific optical resonances due to strong interparticle coupling, which are well reproduced by finite-difference time-domain (FDTD) simulations. The gaps between NPs form a regular lattice of hot spots that enable a large amplification of both photoluminescence and Raman signals. At smaller wavelengths the hot spots are extended away from the minimum-gap positions, which allows SERS of larger analytes that do not fit into small gaps. Using CdSe quantum dots (QDs) a 3-5 times larger photoluminescence enhancement than previously reported is experimentally demonstrated and an unambiguous estimate of the electromagnetic SERS enhancement factor of ?10(4) is obtained by direct scanning electron microscopy imaging of QDs responsible for the Raman signal. Much stronger enhancement of ?10(8) is obtained at larger wavelengths for benzenethiol molecules penetrating the NP gaps.
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H-PDLC based waveform controllable optical choppers for FDMF microscopy.
Opt Express
PUBLISHED: 03-04-2011
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An electrically waveform controllable optical chopper based on holographic polymer dispersed liquid crystal grating (H-PDLC) is presented in this paper. The theoretical analyses and experimental results show that the proposed optical chopper has following merits: (1) controllable waveform, (2) no mechanical motion induced vibrational noise, and ?(3) multiple-channel integration capability. The application of this unique electrically controllable optical chopper to frequency division multiplexed fluorescent microscopy is also addressed in this paper, which has the potential to increase the channel capacity, the stability and the reliability. This will be beneficial to the parallel detection, especially for dynamic studies of living biological samples.
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Trends in live births in the past 20 years in Zhengzhou, China.
Acta Obstet Gynecol Scand
PUBLISHED: 02-14-2011
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To evaluate changing trends in neonatal births and deaths in a provincial womens and childrens hospital over the past 20 years. Design: Retrospective longitudinal study.
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Cell culture and gene transcription effects of copper sulfate on Chinese hamster ovary cells.
Biotechnol. Prog.
PUBLISHED: 01-24-2011
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This study reports the effects of varying concentrations of copper sulfate on the metabolic and gene transcriptional profile of a recombinant Chinese hamster ovary (CHO) cell line producing an immunoglobulin G (IgG)-fusion protein (B0). Addition of 50 ?M copper sulfate significantly decreased lactate accumulation in the cultures while increasing viable cell density and protein titer. These changes could be seen from day 6 and became increasingly evident with culture duration. Reducing the copper sulfate concentration to 5 ?M retained all the above beneficial effects, but with the added benefit of reduced levels of the aggregated form of the B0 protein. To profile the cellular changes due to copper sulfate addition at the transcriptional level, Affymetrix® CHO microarrays were used to identify differentially expressed genes related to reduced cellular stresses and facilitated cell cycling. Based on the microarray results, down-regulation of the transferrin receptor and lactate dehydrogenase, and up-regulation of a cytochrome P450 family-2 polypeptide were then confirmed by Western blotting. These results showed that copper played a critical role in cell metabolism and productivity on recombinant CHO cells and highlighted the usefulness of microarray data for better understanding biological responses on medium modification.
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Fungal community associated with fermentation and storage of Fuzhuan brick-tea.
Int. J. Food Microbiol.
PUBLISHED: 01-18-2011
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Chinese Fuzhuan brick-tea is a unique microbial fermented tea characterized by a period of fungal growth during its manufacturing process. The aim of the present study was to characterize, both physicochemically and microbiologically, traditional industrial production processes of Fuzhuan brick-tea. Fermenting tea samples were collected from the largest manufacturer. Physicochemical analyses showed that the low water content in the tea substrates provided optimal growth conditions for xerophilic fungi. The fungal communities existing in tea materials, fermenting tea, and stored teas were monitored by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) targeting the D1 region of the 26S rRNA genes, followed by sequencing of the amplicons. Results revealed that the microorganisms were from, or closely related to, the genera Eurotium, Debaryomyces, Aspergillus, Verticillium, Pichia, Pestalotiopsis, Rhizomucor and Beauveria. This is the first report of Debaryomyces participating in the processing of Fuzhuan brick-tea. We concluded that the dominant genera Eurotium, Debaryomyces and Aspergillus are beneficial fungi associated with the fermentation of Fuzhuan brick-tea. The genus Beauveria was present in the stored Fuzhuan brick-tea, which may help protect tea products from insect spoilage. The remaining four genera were of minor importance in the manufacturing of Fuzhuan brick-tea. The predominant Eurotium species, a strain named Eurotium sp. FZ, was phenotypically and genotypically identified as Eurotium cristatum. High performance thin layer chromatography analysis of anthraquinones showed that emodin existed in all the dark tea samples, but physcion was only detectable in the tea fermented by E. cristatum. The PCR-DGGE approach was an effective and convenient means for profiling the fungal communities in Fuzhuan brick-tea. These results may help promote the use of microbial consortia as starter cultures to stabilize and improve the quality of Fuzhuan brick-tea products.
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Tailorable integrated optofluidic filters for biomolecular detection.
Lab Chip
PUBLISHED: 01-10-2011
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Spectral filtering is an essential component of biophotonic methods such as fluorescence and Raman spectroscopy. Predominantly utilized in bulk microscopy, filters require efficient and selective transmission or removal of signals at one or more wavelength bands. However, towards highly sensitive and fully self-contained lab-on-chip systems, the integration of spectral filters is an essential step. In this work, a novel optofluidic solution is presented in which a liquid-core optical waveguide both transports sample analytes and acts as an efficient filter for advanced spectroscopy. To this end, the wavelength dependent nature of interference-based antiresonant reflecting optical waveguide technology is exploited. An extinction of 37 dB, a narrow rejection band of only 2.5 nm and a free spectral range of 76 nm using three specifically designed dielectric layers are demonstrated. These parameters result in an 18.4-fold increase in the signal-to-noise ratio for on-chip fluorescence detection. In addition, liquid-core waveguide filters with three operating wavelengths were designed for Förster resonance energy transfer detection and demonstrated using doubly labeled oligonucleotides. Incorporation of high-performance spectral processing illustrates the power of the optofluidic concept where fluidic channels also perform optical functions to create innovative and highly integrated lab-on-chip devices.
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Relationship between CacyBP/SIP expression and prognosis in astrocytoma.
J Clin Neurosci
PUBLISHED: 01-05-2011
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The aim of this study was to investigate the expression of calcyclin-binding protein (also known as Siah-1-interacting protein [CacyBP/SIP]) in astrocytoma and to determine its prognostic value in overall survival of patients with glioblastoma multiforme (GBM). Tissue specimens were obtained from 77 Chinese patients who had undergone surgery for astrocytoma. The expression of CacyBP/SIP was examined by immunohistochemistry. The relationship between CacyBP/SIP and proliferating cell nuclear antigen index (PCNA) expression was investigated, and the prognostic value of CacyBP/SIP expression in patients with astrocytomas was analyzed. Of 77 tumors, 49 (63.6%) were negative for CacyBP/SIP expression. Loss of CacyBP/SIP expression was significantly associated with a high histological grade and with poor survival in univariate and multivariate analyses. Cox multivariable analysis showed that loss of CacyBP/SIP expression correlated with poor prognosis in patients with astrocytomas and was an independent prognostic factor (p<0.05). The mean survival time of patients with tumors that had lost expression of CacyBP/SIP was 25.58months (95% confidence interval [CI], 15.36-25.81months), compared to a mean survival time of 36.37months (95% CI, 27.90-44.84months) for patients with CacyBP/SIP-expressing tumors. CacyBP/SIP expression was also negatively correlated with PCNA expression in astrocytoma tissue (p<0.05). Our findings suggest that CacyBP/SIP may have an important role as a negative regulator of astrocytoma development and progression, and that CacyBP/SIP might be a useful molecular marker for predicting the prognosis of astrocytoma.
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Rational design and application of molecularly imprinted sol-gel polymer for the electrochemically selective and sensitive determination of Sudan I.
Talanta
PUBLISHED: 01-03-2011
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An electrochemical strategy on the basis of rationally designed molecularly imprinted sol-gel polymer embedded with gold nanoparticles (AuNPs) is developed for the specific and sensitive determination of Sudan I. The rationally designed sensing Sudan I imprinted sol-gel was prepared by mixing Sudan I with 3-aminopropyltriethoxysilane, tetraethoxysilane, chitosan, and AuNPs, followed by copolymerization and extraction of the template molecules. The hybrid forming membrane was characterized by SEM and FTIR-ATR, and used for the linear sweep voltammetric (LSV) determination of Sudan I in water/ethanol solutions. The LSV responses exhibited high sensitivity and selectivity, as discriminated from Sudan I analogues. Under optimal experimental conditions, LSV peak currents were linearly proportional to the concentrations of Sudan I in the range from 0.1 × 10(-7) to 1.0 × 10(-5)M, with a detection limit of 2.0 × 10(-9)M. The strategy is generally applicable in developing sensitive, selective, and moreover, reusable electrochemical sensors for quantitative determination of electroactive species.
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CREB influences timing and entrainment of the SCN circadian clock.
J. Biol. Rhythms
PUBLISHED: 12-08-2010
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The transcriptional feedback circuit, which is at the core of the suprachiasmatic nucleus (SCN) circadian (i.e., 24 h) clock, is tightly coupled to both external entrainment cues, such as light, as well as rhythmic cues that arise on a system-wide level within the SCN. One potential signaling pathway by which these cues are conveyed to the molecular clock is the CREB/CRE transcriptional cascade. In this study, we employed a tetracycline-inducible CREB repressor mouse strain, in which approximately 60% of the SCN neurons express the transgene, to test CREB functionality in the clock and its effects on overt rhythmicity. We show that attenuated CREB signaling in the SCN led to a significant reduction in light-evoked clock entrainment. An examination of circadian timing revealed that CREB repressor mice exhibited normal free-running rhythms in the absence of external lighting cues. However, under conditions of constant light, which typically leads to a lengthening of the circadian period, CREB repressor mice exhibited a dramatic arrhythmic phenotype, which could be reversed with doxycycline. At a cellular level, the repression of CREB led to a significant reduction in both the expression of the circadian clock proteins PERIOD1 and PERIOD2 and the clock output hormones AVP and VIP. Together, these data support the idea that the CRE transcriptional pathway orchestrates transcriptional events that are essential for both the maintenance of SCN timing and light entrainment of the circadian clock.
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Transformation-related protein 53 expression in the early mouse embryo compromises preimplantation embryonic development by preventing the formation of a proliferating inner cell mass.
Biol. Reprod.
PUBLISHED: 08-25-2010
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The developmental viability of the preimplantation embryo requires the successful formation of a cluster of pluripotent stem cells called the inner cell mass. Development is variably compromised by a range of exogenous stressors (including their production by assisted reproductive technologies). Inbred C57BL/6 strain embryos are particularly susceptible to the stresses associated with embryo culture, whereas hybrid embryos are more resistant, and this is accounted for in part by the overexpression of transformation-related protein 53 in cultured inbred embryos compared with similarly treated hybrid embryos or embryos not subjected to culture. We show here that this loss of viability is a consequence of the Trp53-dependent reduction in the capacity of blastocysts to form a proliferating inner cell mass. Formation of the trophectodermal line was not adversely affected by these stresses.
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A continuous process for biodiesel production in a fixed bed reactor packed with cation-exchange resin as heterogeneous catalyst.
Bioresour. Technol.
PUBLISHED: 07-10-2010
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Continuous esterification of free fatty acids (FFA) from acidified oil with methanol was carried out with NKC-9 cation-exchange resin in a fixed bed reactor with an internal diameter of 25 mm and a height of 450 mm to produce biodiesel. The results showed that the FFA conversion increased with increases in methanol/oil mass ratio, reaction temperature and catalyst bed height, whereas decreased with increases in initial water content in feedstock and feed flow rate. The FFA conversion kept over 98.0% during 500 h of continuous esterification processes under 2.8:1 methanol to oleic acid mass ratio, 44.0 cm catalyst bed height, 0.62 ml/min feed flow rate and 65°C reaction temperature, showing a much high conversion and operational stability. Furthermore, the loss of sulfonic acid groups from NKC-9 resin into the production was not found during continuous esterification. In sum, NKC-9 resin shows the potential commercial applications to esterification of FFA.
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Proteomic profiling of the epileptic dentate gyrus.
Brain Pathol.
PUBLISHED: 07-04-2010
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The development of epilepsy is often associated with marked changes in central nervous system cell structure and function. Along these lines, reactive gliosis and granule cell axonal sprouting within the dentate gyrus of the hippocampus are commonly observed in individuals with temporal lobe epilepsy (TLE). Here we used the pilocarpine model of TLE in mice to screen the proteome and phosphoproteome of the dentate gyrus to identify molecular events that are altered as part of the pathogenic process. Using a two-dimensional gel electrophoresis-based approach, followed by liquid chromatography-tandem mass spectrometry, 24 differentially expressed proteins, including 9 phosphoproteins, were identified. Functionally, these proteins were organized into several classes, including synaptic physiology, cell structure, cell stress, metabolism and energetics. The altered expression of three proteins involved in synaptic physiology, actin, profilin 1 and ?-synuclein was validated by secondary methods. Interestingly, marked changes in protein expression were detected in the supragranular cell region, an area where robust mossy fibers sprouting occurs. Together, these data provide new molecular insights into the altered protein profile of the epileptogenic dentate gyrus and point to potential pathophysiologic mechanisms underlying epileptogenesis.
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Mammalian target of rapamycin signaling modulates photic entrainment of the suprachiasmatic circadian clock.
J. Neurosci.
PUBLISHED: 05-07-2010
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Inducible gene expression appears to be an essential event that couples light to entrainment of the master mammalian circadian clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Recently, we reported that light triggers phase-dependent activation of the mammalian target of rapamycin (mTOR) signaling pathway, a major regulator of protein synthesis, in the SCN, thus raising the possibility that mTOR-evoked mRNA translation contributes to clock entrainment. Here, we used a combination of cellular, molecular, and behavioral assays to address this question. To this end, we show that the in vivo infusion of the mTOR inhibitor rapamycin led to a significant attenuation of the phase-delaying effect of early-night light. Conversely, disruption of mTOR during the late night augmented the phase-advancing effect of light. To assess the role of mTOR signaling within the context of molecular entrainment, the effects of rapamycin on light-induced expression of PERIOD1 and PERIOD2 were examined. At both the early- and late-night time points, abrogation of mTOR signaling led to a significant attenuation of light-evoked PERIOD protein expression. Our results also reveal that light-induced mTOR activation leads to the translation of mRNAs with a 5-terminal oligopyrimidine tract such as eukaryotic elongation factor 1A and the immediate early gene JunB. Together, these data indicate that the mTOR pathway functions as potent and selective regulator of light-evoked protein translation and SCN clock entrainment.
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Collagen type I regulates beta-catenin tyrosine phosphorylation and nuclear translocation to promote migration and proliferation of gastric carcinoma cells.
Oncol. Rep.
PUBLISHED: 04-08-2010
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The interaction between tumor cells and the stroma environment has crucial effects on tumor cell invasive behavior. As a major component of the stroma, collagen plays a key role on cellular adhesion and epithelial-mesenchymal transition (EMT). Recently, we found that collagen type I is significantly up-regulated in gastric cancer tissues compared with their adjacent non-neoplastic tissues. However, whether collagen type I contributes to gastric cancer invasion and metastasis is not clear. Herein we show that, collagen type I induces cell scattering and cytoskeleton rearrangement, prompts cell migration and proliferation, which indicates that collagen type I is involved in promoting gastric cancer invasion and metastasis. Collagen type I is able to reduce cell-cell adhesion and enhance migration by inducing disassembly of the E-cadherin/catenin complex in gastric carcinoma cells, which is related to tyrosine phosphorylation of beta-catenin. Tyrosine phosphorylation of beta-catenin dissociates it from E-cadherin and actin cytoskeleton and facilitates its entry into the nucleus, where beta-catenin acts as a transcriptional activator inducing genes involved in cell proliferation. In conclusion, collagen type I contributes to invasion and metastasis by regulating beta-catenin tyrosine phosphorylation and nuclear translocation to promote migration and proliferation of gastric carcinoma cells.
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Transcriptomic responses to sodium chloride-induced osmotic stress: a study of industrial fed-batch CHO cell cultures.
Biotechnol. Prog.
PUBLISHED: 03-23-2010
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The rapidly expanding market for monoclonal antibody and Fc-fusion-protein therapeutics has increased interest in improving the productivity of mammalian cell lines, both to alleviate capacity limitations and control the cost of goods. In this study, we evaluated the responses of an industrial CHO cell line producing an Fc-fusion-protein to hyperosmotic stress, a well-known productivity enhancer, and compared them with our previous studies of murine hybridomas (Shen and Sharfstein, Biotechnol Bioeng. 2006;93:132-145). In batch culture studies, cells showed substantially increased specific productivity in response to increased osmolarity as well as significant metabolic changes. However, the final titer showed no substantial increase due to the decrease in viable cell density. In fed batch cultures, hyperosmolarity slightly repressed the cellular growth rate, but no significant change in productivity or final titer was detected. To understand the transcriptional responses to increased osmolarity and relate changes in gene expression to increased productivity and repressed growth, proprietary CHO microarrays were used to monitor the transcription profile changes in response to osmotic stress. A set of osmotically regulated genes was generated and classified by extracting their annotations and functionalities from online databases. The gene list was compared with results previously obtained from similar studies of murine-hybridoma cells. The overall transcriptomic responses of the two cell lines were rather different, although many functional groups were commonly perturbed between them. Building on this study, we anticipate that further analysis will establish connections between productivity and the expression of specific gene(s), thus allowing rational engineering of mammalian cells for higher recombinant-protein productivity.
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High-salt diet during pregnancy and angiotensin-related cardiac changes.
J. Hypertens.
PUBLISHED: 03-11-2010
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High-salt intake has been demonstrated in link to hypertension, and cardiovascular diseases could be programmed in fetal origins. We determined the influence of high-salt diet during pregnancy on the development of the heart.
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Transplantation of magnetically labeled mesenchymal stem cells in a model of perinatal brain injury.
Stem Cell Res
PUBLISHED: 02-25-2010
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Periventricular white matter injury (PVWMI) in preterm infants is a leading cause of cerebral palsy. Mesenchymal stem cell (MSC) transplantation in experimental models of adult demyelinating conditions is reported to reduce neurological deficits so we investigated their potential for treating developmental PVWMI. Neonatal rat MSCs, when cultured and labeled in vitro with fluorescent, micrometer-sized paramagnetic iron oxide particles (MPIO), retained their differentiation potential. Rats received bilateral intracerebral injections of ibotenic acid at postnatal day 5 causing PVWMI-like lesions with localized hypomyelination and sensorimotor deficits. MPIO-labeled MSCs were transplanted near the lesion in the right hemisphere 1 day postlesioning. Animals receiving cell transplants showed significantly increased antimyelin immunoreactivity in the corpus callosum, and improved reaching and retrieval skills, compared to animals receiving conditioned medium only. In separate experiments, in vivo MRI demonstrated that MPIO-labeled cells migrated away from the injection site toward lesioned areas in both hemispheres, confirmed by microscopy postmortem, but double-labeling studies found little evidence of differentiation into neural phenotypes. MSC transplantation led to significantly more forebrain cell proliferation, assayed by bromodeoxyuridine incorporation, than in controls. MSC transplants may have been neuroprotective and indirectly contributed to brain repair.
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Activation of gibberellin 2-oxidase 6 decreases active gibberellin levels and creates a dominant semi-dwarf phenotype in rice (Oryza sativa L.).
J Genet Genomics
PUBLISHED: 02-23-2010
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Gibberellin (GA) 2-oxidase plays a key role in the GA catabolic pathway through 2beta-hydroxylation. In the present study, we isolated a CaMV 35S-enhancer activation tagged mutant, H032. This mutant exhibited a dominant dwarf and GA-deficient phenotype, with a final stature that was less than half of its wild-type counterpart. The endogenous bioactive GAs are markedly decreased in the H032 mutant, and application of bioactive GAs (GA(3) or GA(4)) can reverse the dwarf phenotype. The integrated T-DNA was detected 12.8 kb upstream of the OsGA2ox6 in the H032 genome by TAIL-PCR. An increased level of OsGA2ox6 mRNA was detected at a high level in the H032 mutant, which might be due to the enhancer role of the CaMV 35S promoter. RNAi and ectopic expression analysis of OsGA2ox6 indicated that the dwarf trait and the decreased levels of bioactive GAs in the H032 mutant were a result of the up-regulation of the OsGA2ox6 gene. BLASTP analysis revealed that OsGA2ox6 belongs to the class III of GA 2-oxidases, which is a novel type of GA2ox that uses C20-GAs (GA(12) and/or GA(53)) as the substrates. Interestingly, we found that a GA biosynthesis inhibitor, paclobutrazol, positively regulated the OsGA2ox6 gene. Unlike the over-expression of OsGA2ox1, which led to a high rate of seed abortion, the H032 mutant retained normal flowering and seed production. These results indicate that OsGA2ox6 mainly affects plant stature, and the dominant dwarf trait of the H032 mutant can be used as an efficient dwarf resource in rice breeding.
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Systems genetics analysis of gene-by-environment interactions in human cells.
Am. J. Hum. Genet.
PUBLISHED: 01-21-2010
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Gene by environment (GxE) interactions are clearly important in many human diseases, but they have proven to be difficult to study on a molecular level. We report genetic analysis of thousands of transcript abundance traits in human primary endothelial cell (EC) lines in response to proinflammatory oxidized phospholipids implicated in cardiovascular disease. Of the 59 most regulated transcripts, approximately one-third showed evidence of GxE interactions. The interactions resulted primarily from effects of distal-, trans-acting loci, but a striking example of a local-GxE interaction was also observed for FGD6. Some of the distal interactions were validated by siRNA knockdown experiments, including a locus involved in the regulation of multiple transcripts involved in the ER stress pathway. Our findings add to the understanding of the overall architecture of complex human traits and are consistent with the possibility that GxE interactions are responsible, in part, for the failure of association studies to more fully explain common disease variation.
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Changed salt appetite and central angiotensin II-induced cellular activation in rat offspring following hypoxia during fetal stages.
Peptides
PUBLISHED: 01-09-2010
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Hypoxia in pregnancy may induce fetal growth restriction and cause functional abnormalities during development. The present study determined the long-term influence of hypoxia in fetal life on dipsogenic behavior linked to central angiotensin (Ang) network in the offspring rats. Fetal blood pO(2) and body weight were decreased by hypoxia during pregnancy, followed by a postnatal "catch-up" growth. Subcutaneous hypertonic saline or intracerebroventricular Ang II significantly increased salt intake in the offspring prenatally exposed to hypoxia, while water intake was the same between the two groups. Ang II-induced c-fos expression was detected in the paraventricular nuclei, median preoptic nuclei, supraoptic nuclei, and subfornical organ in the brain, in association with reduced forebrain AT(2) receptor protein abundance in the offspring prenatally exposed to hypoxia. Levels of central AT(1) receptor protein were not changed between the two groups. Hypoxia during pregnancy could be linked to developmental problems related to behavioral dysfunctions in body fluid regulations in later life, in association with the change in central angiotensin II-mediated neural activation and expression of the Ang II receptor in the brain.
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A high-resolution association mapping panel for the dissection of complex traits in mice.
Genome Res.
PUBLISHED: 01-06-2010
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Systems genetics relies on common genetic variants to elucidate biologic networks contributing to complex disease-related phenotypes. Mice are ideal model organisms for such approaches, but linkage analysis has been only modestly successful due to low mapping resolution. Association analysis in mice has the potential of much better resolution, but it is confounded by population structure and inadequate power to map traits that explain less than 10% of the variance, typical of mouse quantitative trait loci (QTL). We report a novel strategy for association mapping that combines classic inbred strains for mapping resolution and recombinant inbred strains for mapping power. Using a mixed model algorithm to correct for population structure, we validate the approach by mapping over 2500 cis-expression QTL with a resolution an order of magnitude narrower than traditional QTL analysis. We also report the fine mapping of metabolic traits such as plasma lipids. This resource, termed the Hybrid Mouse Diversity Panel, makes possible the integration of multiple data sets and should prove useful for systems-based approaches to complex traits and studies of gene-by-environment interactions.
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Pupal cuticle protein is abundant during early adult diapause in the mosquito Culex pipiens.
J. Med. Entomol.
PUBLISHED: 12-08-2009
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Using a proteomics approach, we identified 13 differentially abundant proteins in heads of nondiapause, early, and mid-diapause Culex pipiens L. adult females. Three proteins that were more abundant during early diapause showed highest identities to pupal cuticle protein (PCP). The majority of less abundant proteins were involved in energy metabolism and cytoskeletonal reorganization. The increase of PCP in early diapause may be involved in enhancing stress resistance in the cuticle, a response akin to the general enhancement of stress resistance associated with overwintering insects. PCP also may have utility as a biomarker for early diapause in this species.
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Genome-wide comparative analysis of the metalloprotease ftsH gene families between Arabidopsis thaliana and rice.
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 11-27-2009
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Filamentation temperature-sensitive H (FtsH) is an ATP-dependent metalloprotease in prokaryotes and eukaryotes. Homology-based analysis was applied to determine 12 ftsH genes in Arabidopsis genome and 9 members in rice genome. Distribution of these ftsH genes on each chromosome displayed a clear preference for some chromosomes such as chromosome 1, 2, 5 of Arabidopsis and chromosome 1,5 of rice. All 21 FtsH proteins were subcellularly targeted to chloroplast or mitochondria. These members could be phylogenetically assorted as eight groups, of which no ortholog of AtFtsH12 in rice was detected. Paralogs in each group shared similarity higher than 80% and orthologs higher than 70%. This strongly indicated that the members from single group were descended from a common ancestral gene. Four pairs of paralogs, AtftsH1/5, AtftsH2/8, AtftsH7/9 and AftsH3/10 were found in Arabidopsis genome. However, only two pairs of ftsH paralogs, OsftsH3/8 and OsftsH4/5, resided in rice genome. The highly homologous members in each group performed striking conservation of exon-intron boundaries and preference for the variable residues in function domains. By contrast, there was significant difference in base composition and sequence length of introns. The comparative analysis of the ftsH gene families of Arabidopsis and rice provided the basis for characteristic and function research of ftsH genes in other plants.
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The effect of tanshinone IIA on renal and liver functions in ovine fetuses in utero.
Drug Chem Toxicol
PUBLISHED: 10-02-2009
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This was the first study in determination of the effects of the herbal medicine, danshen, on fetal hepatic and renal functions in utero. Tanshinone IIA, an active ingredient of danshen, was tested in the experimental fetal model. Three doses (20, 40, or 80 mg) of tanshinone IIA and 0.9% NaCl (as the control) were intravenously (i.v.) administrated into pregnant ewes. Both maternal and fetal blood samples were collected and analyzed for renal and liver functions by examining the enzymes and renal excretion. The results showed that tanshinone IIA did not alter fetal urine volume, urine electrolytes, and osmolality. Enzyme activities related to the hepatic and renal functions were not changed. In addition, maternal application of tanshinone IIA had no effect of maternal and fetal lipid profile. The results demonstrated that tanshinone IIA used during the last third of gestation did not cause the biochemical changes related to renal and liver functions in both the mother and fetus. This provides new information to guide the use of herbal medicine during pregnancy.
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Prenatal dehydration alters renin-angiotensin system associated with angiotensin-increased blood pressure in young offspring.
Hypertens. Res.
PUBLISHED: 09-25-2009
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The renin-angiotensin system (RAS) has an important role in cardiovascular homeostasis. This study determined the influence of water deprivation during pregnancy on the development of the RAS in rats, and examined blood pressure (BP) in the adolescent offspring. Pregnant rats were water deprived for 3 days at late gestation, and we examined fetal cardiac ultrastructure, as well as heart angiotensin (Ang) II receptor protein and mRNA, liver angiotensinogen and plasma Ang II concentrations. We also tested cardiovascular responses to i.v. Ang II in the young offspring. In utero exposure to maternal water deprivation significantly decreased fetal body and heart weight, and increased fetal plasma sodium and osmolality. Fetal liver angiotensinogen mRNA, plasma Ang I and Ang II concentrations were also increased. Although fetal AT(1a) and AT(1b) receptor mRNA and AT(1) protein were not changed, AT(2) receptor mRNA and protein levels in the heart were significantly increased following maternal dehydration. Prenatal exposure to maternal water deprivation had no effect on baseline BP; however, it significantly increased BP in response to i.v. Ang II infusion, and decreased baroreflex sensitivity in the offspring. In addition, the heart AT(2) receptor mRNA and protein were higher in the offspring exposed to prenatal dehydration. The results of this study demonstrate that prenatal dehydration affected the RAS development associated with an Ang II-increased BP in fetal origin.
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Al3+-directed self-assembly and their electrochemistry properties of three-dimensional dendriform horseradish peroxidase/polyacrylamide/platinum/single-walled carbon nanotube composite film.
Biosens Bioelectron
PUBLISHED: 08-19-2009
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A novel general methodology for protein immobilization and third-generation biosensor construction is demonstrated, which involves Al(3+)-directed polyacrylamide (PAM) self-assembly into an ordered dendriform structure, easily immobilizing enzymes and nanoparticles. Platinum/single-walled carbon nanotube (Pt/SWCNT) heterojunction nanomaterials were for the first time fabricated via an EDTA-directed synthesis strategy. The Pt/SWCNTs were employed as a supporting matrix to explore a novel immobilization and biosensing platform of redox proteins through cooperating Al(3+)-directed PAM self-assembly. Compared with the almost single-layer horseradish peroxidase (HRP)/PAM film electrode, multilayer HRP/PAM/Pt/SWCNT film electrode exhibited a pair of much stronger redox peaks at -0.22 V (vs. Ag/AgCl). Moreover, with advantages of the ordered multilayer HRP/PAM/Pt/SWCNT film, facilitated direct electron transfer of the metalloenzymes with an apparent heterogeneous electron transfer rate constant (k(s)) of 14.94+/-1.36 s(-1) and smaller peak-to-peak separation (DeltaE(p)) of about 37 mV was acquired on the PAM/Pt/SWCNT-based enzyme electrode. The PAM/Pt/SWCNT-based biosensor demonstrated significant electrocatalytic activity for the reduction of hydrogen peroxide with a small apparent Michaelis-Menten constant (87 microM), wide linear range (1-270 microM), very low detection limit (0.08 microM, S/N=3), and high sensitivity (372 mA cm(-2) M(-1)). Together, these indicated that the Al(3+)-directed HRP/PAM/Pt/SWCNT film was one of ideal candidate materials for direct electrochemistry of redox proteins and the construction of the related enzyme biosensors, and may find potential applications in biomedical, food, and environmental analysis and detection.
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Neuropeptide-like precursor 4 is uniquely expressed during pupal diapause in the flesh fly.
Peptides
PUBLISHED: 06-06-2009
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Suppression subtractive hybridization comparing brains from diapausing and nondiapausing pupae of the flesh fly, Sarcophaga crassipalpis, suggested that the gene encoding neuropeptide-like precursor 4 (Nplp4) was uniquely expressed during diapause. We have sequenced the full-length cDNA encoding Nplp4 and used Northern blots to further evaluate linkage to diapause. The open reading frame of this cDNA encodes a 61-amino acid residue precursor protein containing a predicted 18 residue signal peptide, one 22-amino acid and one 2-amino acid propeptides, and a 19-amino acid neuropeptide. The amino acid sequence of the precursor protein shows 64% identity to Drosophila melanogaster Nplp4; homologues of this precursor protein are not known from species other than these two flies. Nplp4 mRNA levels were quite low in nondiapausing (long day) pupae, but in contrast the gene was highly upregulated in diapausing (short day) pupae. Expression increased at the onset of diapause, remained high throughout diapause, and then decreased 2 days after diapause was terminated. Although the function of this precursor protein and the neuropeptide it yields remain unknown, this close association with diapause suggests a potential role for Nplp4 in initiating and maintaining diapause in the flesh fly.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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