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Find video protocols related to scientific articles indexed in Pubmed.
Unfolded protein response-induced ERdj3 secretion links ER stress to extracellular proteostasis.
EMBO J.
PUBLISHED: 10-31-2014
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The Unfolded Protein Response (UPR) indirectly regulates extracellular proteostasis through transcriptional remodeling of endoplasmic reticulum (ER) proteostasis pathways. This remodeling attenuates secretion of misfolded, aggregation-prone proteins during ER stress. Through these activities, the UPR has a critical role in preventing the extracellular protein aggregation associated with numerous human diseases. Here, we demonstrate that UPR activation also directly influences extracellular proteostasis through the upregulation and secretion of the ER HSP40 ERdj3/DNAJB11. Secreted ERdj3 binds misfolded proteins in the extracellular space, substoichiometrically inhibits protein aggregation, and attenuates proteotoxicity of disease-associated toxic prion protein. Moreover, ERdj3 can co-secrete with destabilized, aggregation-prone proteins in a stable complex under conditions where ER chaperoning capacity is overwhelmed, preemptively providing extracellular chaperoning of proteotoxic misfolded proteins that evade ER quality control. This regulated co-secretion of ERdj3 with misfolded clients directly links ER and extracellular proteostasis during conditions of ER stress. ERdj3 is, to our knowledge, the first metazoan chaperone whose secretion into the extracellular space is regulated by the UPR, revealing a new mechanism by which UPR activation regulates extracellular proteostasis.
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SKLB-M8 Induces Apoptosis Through the AKT/mTOR Signaling Pathway in Melanoma Models and Inhibits Angiogenesis With Decrease of ERK1/2 Phosphorylation.
J. Pharmacol. Sci.
PUBLISHED: 10-21-2014
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SKLB-M8, a derivative of millepachine, showed significant anti-proliferative effects in melanoma cell lines. In this study, we investigated the anti-melanoma and anti-angiogenic activity of SKLB-M8 on three melanoma cell lines (A2058, CHL-1, and B16F10) and human umbilical vein endothelial cells (HUVECs). In vitro, SKLB-M8 showed anti-proliferative activity with IC50 values of 0.07, 0.25, and 0.88 ?M in A2058, CHL-1, and B16F10 cell lines, respectively. Flow cytometory analysis showed that SKLB-M8 induced G2/M arrest in three melanoma cell lines, and western blotting demonstrated that SKLB-M8 down-regulated the expression of cdc2, up-regulated p53 in A2058 and CHL-1 cells, and triggered cell apoptosis through down-regulating AKT and phosphorylated mTOR (p-mTOR). SKLB-M8 also inhibited HUVEC proliferation, migration, invasion, and tube formation in vitro with the inhibition of phosphorylated ERK1/2 (p-ERK1/2). In vivo, alginate-encapsulated tumor cell assay revealed that SKLB-M8 suppressed B16F10 tumor angiogenesis. In CHL-1- and B16F10-tumor-bearing mouse models, SKLB-M8 inhibited tumor growth by oral treatment with less toxicity. CD31 immunofluoresence staining and caspase-3 immunohistochemistry indicated that SKLB-M8 inhibited melanoma tumor growth by targeting angiogenesis and inducing caspase3-dependent apoptosis. SKLB-M8 might be a potential anti-melanoma drug candidate.
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Facile Assembly of Ni-Co Hydroxide Nanoflakes on Carbon Nanotube Network with Highly Electrochemical Capacitive Performance.
ACS Appl Mater Interfaces
PUBLISHED: 10-15-2014
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Herein, we demonstrate the high-density assembly of Ni-Co hydroxide nanoflakes on conductive carbon nanotube (CNT) network through a simple and rapid chemical precipitation method, presenting a low-cost and high-performance scaffold for pseudosupercapacitor. It is found that the Ni-Co layered double hydroxide (LDH) nanoflakes prefer to proliferate around large-diameter CNTs (diameter > 50 nm), with conductive CNT network well-maintained. Such hierarchical nanostructures show greatly improved specific surface areas compared with bare CNT network and are freestanding without other organic binder, which can be directly employed as a binder-free compact electrode assembly. By optimizing the chemical composition of as-precipitated LDH nanoflakes, the resultant Co0.4Ni0.6(OH)2 LDH/CNT composite nanostructures exhibit the largest specific electrochemical capacitance and the best rate performance, with their capacitance up to 1843 F/g under a low current density of 0.5 A/g and maintained at 1231 F/g when the current density is increased 20 times to 10 A/g. Importantly, such hierarchical nanostructures tend to prevent the electrode from severe structural damage and capacity loss during hundreds of charge/discharge under a high rate (2 A/g), ensuring the electrode with high-energy density (51 W h/kg) at power density of 3.3 kW/kg.
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Synthesis and biological evaluation of novel millepachine derivatives as a new class of tubulin polymerization inhibitors.
J. Med. Chem.
PUBLISHED: 09-29-2014
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Twenty-one novel derivatives of millepachine were synthesized and evaluated for their in vitro antiproliferative activity. Among them, 8 exhibited the most potent activity, with IC50 values of 8-27 nM against panel of cancer cell lines and retained full activity in multidrug resistant cancer cells. Treated cells were arrested in G2/M phase and resulted in cellular apoptosis. Microtubule dynamics confirmed 8 was a novel tubulin polymerization inhibitor by binding at the colchicine site. 8 also exhibited antivascular activity because it concentration dependently reduced the cell migration and disrupted capillary like tube formation in HUVEC cells. Furthermore, the hydrochloride salt of 8 (8·HCl) significantly improved the bioavailability up to 47% while retaining the antiproliferative activity. Importantly, 8·HCl significantly inhibited tumor growths in four xenograft models including resistance tumor-cell-bearing mice models without causing significant loss of body weight, suggesting that 8 is a promising new orally anticancer agent to be developed.
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[The effect of nasal irrigation in the treatment of allergic rhinitis].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 09-05-2014
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To compare the symptoms and lower airway inflammatory factors of patients with allergic rhinitis (AR), and to observe the effect of nasal irrigation in the treatment of allergic rhinitis.
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Synthesis and lipid-lowering evaluation of 3-methyl-1H-purine-2,6-dione derivatives as potent and orally available anti-obesity agents.
Eur J Med Chem
PUBLISHED: 08-08-2014
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Obesity accompanied with metabolic disorder is often complicated with a strong link of dyslipidemia and insulin resistance, whose indicator is the excess accumulation of triglycerides (TG) in cells. Consideration the idea of lipid-lowering and improving insulin resistance, 34 novel compounds by combination the xanthine scaffold with the chain of Rosiglitazone have been synthesized. Among them, several compounds showed efficiency on reducing TG in 3T3-L1 adipoctyes, and 11c exhibited the most optimal capacity in lipid-lowering and improving obese clinical symptoms in DIO mice. Furthermore, the hydrochloride of 11c (11c·HCl) showed excellent bioavailability, 58.94%, over 2 folds than that (28.03%) of 11c, and the anti-obesity effect of 11c·HCl at 50 mg/kg dose was better than that of Metformin at 150 mg/kg dose in DIO mice, almost reversed HFD to a normal level. Thus, 11c·HCl might be a potent and orally available anti-obesity agent via alleviating the obese clinical symptoms, body fat, improving serum parameters and insulin resistance and TG clearance in liver.
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Millettia pachycarpa exhibits anti-inflammatory activity through the suppression of LPS-induced NO/iNOS expression.
Am. J. Chin. Med.
PUBLISHED: 07-10-2014
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The present study was designed to investigate the in vitro and in vivo anti-inflammatory activity of flavonoids isolated from Millettia pachycarpa Benth. The seeds of M. pachycarpa Benth were extracted with ethanol and subjected to chromatographic separation for the isolation of bioactive compounds. Their structures were elucidated by spectroscopic methods. The anti-inflammatory activity of the compounds was investigated by evaluating the inhibition ability of NO production, iNOS activity and iNOS protein expression induced by LPS-stimulated RAW264.7 macrophages in vitro and the carrageenan-induced hind paw edema model in vivo. Molecular docking simulation was also employed to obtain the binding parameters in the binding pocket of iNOS. Thirteen compounds (1-13) were isolated from Chinese herbal medicine M. pachycarpa Benth. Among them, 4-hydroxylonchocarpin (6) and deguelin (7) exhibited remarkable inhibitory rates of 66.5% and 57.7%, respectively, compared with that of 52.5% of indomethacin in LPS-induced macrophages cells. 4-hydroxylonchocarpin (6) with low toxicity (IC50 > 100 ?m) exhibited better inhibitory effects to positive control of 1400W on iNOS activity at the concentration of 10 ?m. Western blot assay revealed that 4-hydroxylonchocarpin (6) inhibited iNOS protein expression in RAW264.7 cells and molecular docking simulation showed that 4-hydroxylonchocarpin (6) fit well into the binding pocket of iNOS. In the carrageenan-induced paw edema model, our data revealed that the anti-inflammatory potential of 4-hydroxylonchocarpin (6) at 10 mg/kg showed comparable inhibitory ability to indomethacin at 5 h while a higher concentration of 4-hydroxylonchocarpin (6) at 50 mg/kg showed higher inhibitory activity than indomethacin, which was further confirmed by plasma levels of nitrite. The overall results suggest that 4-hydroxylonchocarpin (6) might be used as a potential therapeutic agent for inflammation-associated disorders.
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Enhanced expression of recombinant elastase in Pichia pastoris through addition of N-glycosylation sites to the propeptide.
Biotechnol. Lett.
PUBLISHED: 05-26-2014
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N-Glycosylation is a common form of protein post-translational modification in Pichia pastoris and greatly affects folding and secretion. The propeptide of the Pseudomonas aeruginosa elastase (PAE) is indispensable for proper folding and secretion of the enzyme. We have studied the effect of introducing N-glycosylation sites to the propeptide of the recombinant elastase (rPAE) on its expression levels in P. pastoris. Addition of N-glycosylation sites to the propeptide at N51 or N93 enhanced rPAE production levels by 104 or 57 %, respectively, while addition at N11 or N127 led to a 25 or 50 % decrease, respectively. The introduced N-glycosylation sites in the propeptide at these four sites exerted a null effect on the N-glycosylation degree of mature rPAE.
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Enhanced Expression of Recombinant Elastase in Pichia pastoris through the Substitution of Thr for Ser in Asn-Xaa-Ser Sequons.
Appl. Biochem. Biotechnol.
PUBLISHED: 05-12-2014
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N-glycosylation usually occurs at the Asn-Xaa-Ser/Thr sequon of glycoproteins in Pichia pastoris, exerting great effects on expression efficiency; however, Asn-Xaa-Thr is more efficiently glycosylated than Asn-Xaa-Ser. In this study, the role of the two sequons in the expression of recombinant elastase (rPAE) was investigated. At N43, N212, and N280 of rPAE, Asn-Xaa-Thr was substituted for the native Asn-Xaa-Ser sequon through site-directed mutagenesis, and the two sequon forms were introduced into rPAE at N36 and N264. As expected, substitution at N36, N43, N212, and N280 enhanced the degree of N-glycosylation. At N212 or N280, substitution increased rPAE production effectively by 43 and 25 %, respectively. In comparison, at N36, N43, and N264, the change inhibited rPAE expression to varying extents; specifically, substitution at N36 resulted in a 31 % decrease, while substitution at N43 or N264 resulted in a decrease of less than 9 %. It is suggested that the effect of the substitution of Asn-Xaa-Thr for Asn-Xaa-Ser on rPAE expression is roughly related to the role of the original Asn-Xaa-Ser sequon. As the conversion of Ser to Thr at N-glycosylation sites through site-directed mutagenesis is easily achieved, it is a feasible means of improving the expression of recombinant proteins in P. pastoris.
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Roles of limbal microvascular net and limbal stroma in regulating maintenance of limbal epithelial stem cells.
Cell Tissue Res.
PUBLISHED: 04-08-2014
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Knowledge of the microenvironment (niche) of stem cells is helpful for stem-cell-based regenerative medicine. In the eye, limbal epithelial stem cells (corneal epithelial stem cells) provide the self-renewal capacity of the corneal epithelium and are essential for maintaining corneal transparency and vision. Limbal epithelial stem cell deficiency results in significant visual deterioration. Successful treatment of this type of blinding disease requires studies of the limbal epithelial stem cells and their microenvironment. We investigate the function of the limbal microvascular net and the limbal stroma in the maintenace of the limbal epithelial stem cell niche in vivo and examine the regulation of limbal epithelial stem cell survival, proliferation and differentiation in vivo. We assess the temporal and spatial changes in the expression patterns of the following markers during a six-month follow-up of various rabbit limbal autograft transplantation models: vascular endothelial cell marker CD31, corneal epithelium differentiation marker K3, limbal epithelial stem-cell-associated markers P63 and ABCG2 and proliferating cell nuclear marker Ki67. Our results suggest that limbal epithelial stem cells cannot maintain their stemness or proliferation without the support of the limbal microvascular net microenvironment. Thus, both the limbal microvascular net and the limbal stroma play important roles as components of the limbal epithelial stem cell niche maintaining limbal epithelial stem cell survival and proliferation and the avoidance of differentiation. The limbal stroma constitutes the structural basis of the limbal epithelial stem cell niche and the limbal microvascular net is a requirement for this niche. These new insights should aid the eventual construction of tissue-engineered cornea for corneal blind patients in the future.
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Euclidean sections of protein conformation space and their implications in dimensionality reduction.
Proteins
PUBLISHED: 03-12-2014
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Dimensionality reduction is widely used in searching for the intrinsic reaction coordinates for protein conformational changes. We find the dimensionality-reduction methods using the pairwise root-mean-square deviation (RMSD) as the local distance metric face a challenge. We use Isomap as an example to illustrate the problem. We believe that there is an implied assumption for the dimensionality-reduction approaches that aim to preserve the geometric relations between the objects: both the original space and the reduced space have the same kind of geometry, such as Euclidean geometry vs. Euclidean geometry or spherical geometry vs. spherical geometry. When the protein free energy landscape is mapped onto a 2D plane or 3D space, the reduced space is Euclidean, thus the original space should also be Euclidean. For a protein with N atoms, its conformation space is a subset of the 3N-dimensional Euclidean space R(3N). We formally define the protein conformation space as the quotient space of R(3N) by the equivalence relation of rigid motions. Whether the quotient space is Euclidean or not depends on how it is parameterized. When the pairwise RMSD is employed as the local distance metric, implicit representations are used for the protein conformation space, leading to no direct correspondence to a Euclidean set. We have demonstrated that an explicit Euclidean-based representation of protein conformation space and the local distance metric associated to it improve the quality of dimensionality reduction in the tetra-peptide and ?-hairpin systems.
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Bioactivity-guided isolation of anti-inflammation flavonoids from the stems of Millettia dielsiana Harms.
Fitoterapia
PUBLISHED: 03-04-2014
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Bioactivity-guided isolation of the EtOAc extract of the stems of Millettia dielsiana Harms yielded two new isoflavones together with nine known ones. Their structures were elucidated by analysis of the spectroscopic data including 2D NMR. All of the isolates were evaluated for their potential to inhibit the LPS-induced production of nitric oxide and TNF-? in murine macrophage RAW 264.7 cells. Among the tested compounds, Millesianin C (1) had the most potent anti-inflammatory effect decreasing NO production similar to that of dexamethasone and decreasing TNF-? secretion better than that of dexamethasone. Their structure-activity relationship was also analyzed.
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The effect of copper on iron reduction and its application to the determination of total iron content in iron and copper ores by potassium dichromate titration.
Talanta
PUBLISHED: 02-26-2014
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The International Standard Organization (ISO) specifies two titrimetric methods for the determination of total iron content in iron ores using potassium dichromate as titrant after reduction of the iron(III) by tin(II) chloride and/or titanium(III) chloride. These two ISO methods (ISO2597-1 and ISO2597-2) require nearly boiling-point temperature for iron(III) reduction and suffer from copper interference and/or mercury pollution. In this study, potassium borohydride was used for reduction of iron(III) catalyzed by copper ions at ambient temperatures. In the absence of copper, iron(III) reduction by potassium borohydride was sluggish while a trace amount of copper significantly accelerated the reduction and reduced potassium borohydride consumption. The catalytic mechanism of iron(III) reduction in sulfuric acid and hydrochloric acid was investigated. Potassium borohydride in sodium hydroxide solution was stable without a significant degradation within 24h at ambient conditions and the use of potassium borohydride prepared in sodium hydroxide solution was safe and convenient in routine applications. The applicability of potassium borohydride reduction for the determination of total iron content by potassium dichromate titration was demonstrated by comparing with the ISO standard method using iron and copper ore reference materials and iron ore samples.
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Characterization of metabolic profile of honokiol in rat feces using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and (13)C stable isotope labeling.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 01-25-2014
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As fecal excretion is one of important routes of elimination of drugs and their metabolites, it is indispensable to investigate the metabolites in feces for more comprehensive information on biotransformation in vivo. In this study, a sensitive and reliable approach based on ultra-performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF-MS) was applied to characterize the metabolic profile of honokiol in rat feces after the administration of an equimolar mixture of honokiol and [(13)C6]-labeled honokiol. Totally 42 metabolites were discovered and tentatively identified in rat feces samples, 26 metabolites were first reported, including two novel classes of metabolites, methylated and dimeric metabolites of honokiol. Moreover, this study provided basic comparative data on the metabolites in rat plasma, feces and urine, which gave better understanding of the metabolic fate of honokiol in vivo.
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Integrative genomic analyses of the histamine H1 receptor and its role in cancer prediction.
Int. J. Mol. Med.
PUBLISHED: 01-23-2014
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The human histamine receptor H1 (HRH1) gene is located on chromosome 3p25 and encodes for a 487 amino acid G protein-coupled receptor (GPCR) with a long third intracellular loop (IL3). The HRH1 predominantly couples to G?q/11 proteins, leading to the activation of phospholipase C (PLC) and subsequent release of the second messengers inositol trisphosphate (IP3) and diacylglycerol (DAG) followed by the activation of PKC and the release of [Ca2+]i. In the present study, we identified HRH1 genes from 14 vertebrate genomes and found that HRH1 exists in all types of vertebrates including fish, amphibians, birds and mammals. We identified 88 SNPs including 4 available alleles disrupting an existing exonic splicing enhancer and 84 SNPs causing missense mutation, which may impact the effect of histamine on the HRH1 protein. We found that the human HRH1 gene was expressed in many tissues or organs, and predominant expression of HRH1 was shown in the bone marrow, whole blood, lymph node, thymus, brain, cerebellum, retina, spinal cord, heart, smooth muscle, skeletal muscle, small intestine, colon, adipocytes, kidney, liver, lung, pancreas, thyroid salivary gland, skin, ovary, uterus, placenta, prostate and testis. When searched in the PrognoScan database, human HRH1 was also found to be expressed in bladder cancer, blood cancer, brain cancer, breast cancer, colorectal cancer, eye cancer, head and neck cancer, lung cancer, ovarian cancer, skin cancer and soft tissue cancer tissues. The relationship between the expression of HRH1 and prognosis was found to vary in different types of cancers, even in the same cancer from different databases. This implies that the function of HRH1 in these tumors may be multidimensional. GR, STAT5A and c-Myb regulatory transcription factor binding sites were identified in the HRH1 gene upstream (promoter) region, which may be involved in the effect of HRH1 in tumors.
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A novel mycovirus closely related to viruses in the genus Alphapartitivirus confers hypovirulence in the phytopathogenic fungus Rhizoctonia solani.
Virology
PUBLISHED: 01-22-2014
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We report here the biological and molecular attributes of a novel dsRNA mycovirus designated Rhizoctonia solani partitivirus 2 (RsPV2) from strain GD-11 of R. solani AG-1 IA, the causal agent of rice sheath blight. The RsPV2 genome comprises two dsRNAs, each possessing a single ORF. Phylogenetic analyses indicated that this novel virus species RsPV2 showed a high sequence identity with the members of genus Alphapartitivirus in the family Partitiviridae, and formed a distinct clade distantly related to the other genera of Partitiviridae. Introduction of purified RsPV2 virus particles into protoplasts of a virus-free virulent strain GD-118 of R. solani AG-1 IA resulted in a derivative isogenic strain GD-118T with reduced mycelial growth and hypovirulence to rice leaves. Taken together, it is concluded that RsPV2 is a novel dsRNA virus belonging to Alphapartitivirus, with potential role in biological control of R. solani.
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Exome sequencing identified new mutations in a Marfan syndrome family.
Diagn Pathol
PUBLISHED: 01-11-2014
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Marfan syndrome is a common autosomal dominant hereditary connective tissue disorder. There is no cure for Marfan syndrome currently. Next-generation sequencing (NGS) technology is efficient to identify genetic lesions at the exome level. Here we carried out exome sequencing of two Marfan syndrome patients. Further Sanger sequencing validation in other five members from the same family was also implemented to confirm new variants which may contribute to the pathogenesis of the disease. Two new variants, including one nonsense SNP in the Marfan syndrome gene FBN1 and one missense mutation in exon 15 of LRP1, which may be related to the phenotype of the patients were identified. The exome sequencing analysis provides us a new insight into the molecular events governing pathogenesis of Marfan syndrome.
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Crack-Free and Scalable Transfer of Carbon Nanotube Arrays into Flexible and Highly Thermal Conductive Composite Film.
ACS Appl Mater Interfaces
PUBLISHED: 12-16-2013
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Carbon nanotube (CNT) arrays show great promise in developing anisotropic thermal conductive composites for efficiently dissipating heat from high-power devices along thickness direction. However, CNT arrays are always grown on some substrates and liable to be deformed and broken into pieces during transfer and solution treatment. In the present study, we intentionally synthesized well-crystallized and large-diameter (?80 nm) multiwalled CNT (MWCNT) arrays by floating catalyst chemical vapor deposition (FCCVD) method. Such arrays provided high packing density and robust structure from collapse and crack formation during post solution treatment and therefore favored to maintain original thermal and electrical conductive paths. Under optimized condition, the CNT arrays can be transferred into flexible composite films. Furthermore, the composite film also exhibited excellent thermal conductivity at 8.2 W/(m·K) along thickness direction. Such robust, flexible, and highly thermal conductive composite film may enable some prospective applications in advanced thermal management.
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Graph representation of protein free energy landscape.
J Chem Phys
PUBLISHED: 12-11-2013
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The thermodynamics and kinetics of protein folding and protein conformational changes are governed by the underlying free energy landscape. However, the multidimensional nature of the free energy landscape makes it difficult to describe. We propose to use a weighted-graph approach to depict the free energy landscape with the nodes on the graph representing the conformational states and the edge weights reflecting the free energy barriers between the states. Our graph is constructed from a molecular dynamics trajectory and does not involve projecting the multi-dimensional free energy landscape onto a low-dimensional space defined by a few order parameters. The calculation of free energy barriers was based on transition-path theory using the MSMBuilder2 package. We compare our graph with the widely used transition disconnectivity graph (TRDG) which is constructed from the same trajectory and show that our approach gives more accurate description of the free energy landscape than the TRDG approach even though the latter can be organized into a simple tree representation. The weighted-graph is a general approach and can be used on any complex system.
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Differentiation of chicken umbilical cord mesenchymal stem cells into beta-like pancreatic islet cells.
Artif Cells Nanomed Biotechnol
PUBLISHED: 12-06-2013
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In this study, we explored the possibility of using in vitro differentiation to create functional beta-like islet cells from chicken umbilical cord mesenchymal stem cells (UCMSCs). Passaged UCMSCs were induced to differentiate into pancreatic beta-like islet cells. Differentiated cells were observed through dithizone staining, and Pdx1 and insulin expressed in differentiated cells were detected with immunofluorescence. Insulin and C-peptide production from differentiated cells were analyzed using ELISA and western blotting. Differentiated cells were found to not only express Pdx1, insulin, and C-peptide, but also to display a glucose-responsive secretion of these hormones.
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Modification of recombinant elastase expressed in Pichia pastoris by introduction of N-glycosylation sites.
J. Biotechnol.
PUBLISHED: 10-29-2013
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A novel N-glycosylation site was introduced into recombinant elastase (rPAE) at N36, N67, or N264 through the site-directed mutagenesis of I38T, A69T, or N266T, respectively. The A69T mutation completely inhibited the expression of rPAE. As expected, the I38T and N266T mutant proteins exhibited higher degrees of N-glycosylation compared with the wild type rPAE. The I38T mutant was more efficient in the hydrolysis of casein in aqueous medium and exhibited higher specific activity and kcat values and a lower Km value. In contrast, the N266T mutant and the wild type displayed similar values. Importantly, the I38T mutant achieved in higher rates and yields of peptide synthesis in 50% (v/v) dimethylsulfoxide, whereas the N266T mutant was similar to the wild type rPAE. Furthermore, the maximum yield of Z-Ala-Phe-NH2 synthesis catalyzed by the I38T mutant protein (87%) was higher than those achieved by the wild type (78%) and N266T mutant (78%) proteins. Neither the I38T nor the N266T mutation exerted significant effects on the rPAE solvent stability. In aqueous medium, the I38T mutation decreased the rPAE thermostability, and the N266T mutation slightly improved that. In conclusion, the I38T mutation improved the potential of rPAE in industrial applications.
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Serotonin Transporter (5-HTT) Gene Polymorphisms and Susceptibility to Epilepsy: A Meta-Analysis and Meta-Regression.
Genet Test Mol Biomarkers
PUBLISHED: 10-05-2013
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Aims: Serotonin transporter (5-HTT) plays a central role in the regulation of serotonin (5-hydroxytryptamine [5-HT]) synaptic function. Disturbances in 5-HT transmission are the most frequently reported neurobiological substrates of suicidal behavior. Emerging evidence has shown that the common polymorphisms in the 5-HTT gene may contribute to the risk of epilepsy, but individually published studies showed inconclusive results. This meta-analysis aimed to derive a more precise estimation of the associations between 5-HTT gene polymorphisms and susceptibility to epilepsy. Methods: A literature search of PubMed, Embase, Web of Science, and China BioMedicine (CBM) databases was conducted on articles published before June 1st, 2013. Crude odds ratios with 95% confidence intervals were calculated. Results: Seven studies were assessed with a total 1303 epilepsy patients and 1288 healthy controls. The meta-analysis results indicated that there was no significant relationship between 5-HTT gene polymorphisms and an increased risk of epilepsy. Further subgroup analysis based on ethnicity also found no significant association between 5-HTT gene polymorphisms and epilepsy risk among both Caucasian and Asian populations. In addition, there was also no significant association between 5-HTT gene polymorphisms and the risk of psychiatric comorbidity in patients with epilepsy. Conclusion: In conclusion, the current meta-analysis indicates that 5-HTT gene polymorphisms might not be the primary determinants of epilepsy susceptibility. 5-HTT genes might be expected to interact with other genes in different signaling pathways to initiate and promote the epileptogenic process.
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[Effects of Jianpi Qinghua Recipe on angiotensin II/NADPH oxidase pathway in 5/6 nephrectomized rats].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 08-29-2013
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To study the effect of Jianpi Qinghua Recipe ( JPQHR) on angiotensin II/NADPH oxidase pathway in 5/6 nephrectomized rat renal failure model and the underlying mechanisms.
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Evaluation of Dimensionality-reduction Methods from Peptide Folding-unfolding Simulations.
J Chem Theory Comput
PUBLISHED: 06-18-2013
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Dimensionality reduction methods have been widely used to study the free energy landscapes and low-free energy pathways of molecular systems. It was shown that the non-linear dimensionality-reduction methods gave better embedding results than the linear methods, such as principal component analysis, in some simple systems. In this study, we have evaluated several non linear methods, locally linear embedding, Isomap, and diffusion maps, as well as principal component analysis from the equilibrium folding/unfolding trajectory of the second ?-hairpin of the B1 domain of streptococcal protein G. The CHARMM parm19 polar hydrogen potential function was used. A series of criteria which reflects different aspects of the embedding qualities were employed in the evaluation. Our results show that principal component analysis is not worse than the non-linear ones on this complex system. There is no clear winner in all aspects of the evaluation. Each dimensionality-reduction method has its limitations in a certain aspect. We emphasize that a fair, informative assessment of an embedding result requires a combination of multiple evaluation criteria rather than any single one. Caution should be used when dimensionality-reduction methods are employed, especially when only a few of top embedding dimensions are used to describe the free energy landscape.
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A "three-in-one" water treatment material: nitrogen-doped tungstic acid.
Chem. Commun. (Camb.)
PUBLISHED: 05-23-2013
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Nitrogen-doped tungstic acid hydrate (N-doped H2W(1.5)O(5.5)·H2O) has been developed as a new kind of efficient "three-in-one" water treatment material. The new material shows excellent uptake capacity towards various aqueous pollutants, as well as good photocatalytic detoxification and visible-light-driven photosensitized degradation performance.
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The role of N-glycosylation sites in the activity, stability, and expression of the recombinant elastase expressed by Pichia pastoris.
Enzyme Microb. Technol.
PUBLISHED: 05-05-2013
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The Pseudomonas aeruginosa elastase (PAE), produced by Pseudomonas aeruginosa (P. aeruginosa), is a promising biocatalyst for peptide synthesis in organic solvents. As P. aeruginosa is an opportunistic pathogen, the enzyme has been heterologously over-expressed in the safe and efficient host, Pichia pastoris (P. pastoris) for its industrial application. The recombinant elastase (rPAE) contains three potential N-glycosylation sites (Asn-Xaa-Ser/Thr consensus sequences), and is heterogeneously N-glycosylated. To investigate the role of N-glycosylation in the activity, stability, and expression of rPAE, these potential N-glycosylation sites (N43, N212, and N280) were mutated using site-directed mutagenesis. Specifically the asparagine (Asn, N) residues were converted to glutamine (Gln, Q). The enzymatic activity and stability of non-glycosylated and glycosylated rPAE were then compared. The results indicated that the influence of N-glycosylation on its activity was insignificant. The non- and glycosylated isoforms of rPAE displayed similar kinetic parameters for hydrolyzing casein in aqueous medium, and when catalyzing bipeptide synthesis in 50% (v/v) DMSO, they exhibited identical substrate specificity and activity, and produced similar yields. However, N-glycosylation improved rPAE stability both in aqueous medium and in 50% (v/v) organic solvents. The half-lives of the glycosylated and non-glycosylated forms of rPAE at 70°C were 32.2 and 23.1min, respectively. Mutation of any potential N-glycosylation site was detrimental to its expression in P. pastoris. There was a 23.9% decrease in expression of the N43Q mutant, 63.6% of the N212Q mutant, and 63.7% of the N280Q mutant compared with the wild type. Furthermore, combined mutation of these sites resulted in an additional decrease in the caseinolytic activities of the mutants. These results indicated that all of the N-glycosylation sites were necessary for high-level expression of rPAE.
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Construction of a Full-Length Enriched cDNA Library and Preliminary Analysis of Expressed Sequence Tags from Bengal Tiger Panthera tigris tigris.
Int J Mol Sci
PUBLISHED: 04-24-2013
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In this study, a full-length enriched cDNA library was successfully constructed from Bengal tiger, Panthera tigris tigris, the most well-known wild Animal. Total RNA was extracted from cultured Bengal tiger fibroblasts in vitro. The titers of primary and amplified libraries were 1.28 × 106 pfu/mL and 1.56 × 109 pfu/mL respectively. The percentage of recombinants from unamplified library was 90.2% and average length of exogenous inserts was 0.98 kb. A total of 212 individual ESTs with sizes ranging from 356 to 1108 bps were then analyzed. The BLASTX score revealed that 48.1% of the sequences were classified as a strong match, 45.3% as nominal and 6.6% as a weak match. Among the ESTs with known putative function, 26.4% ESTs were found to be related to all kinds of metabolisms, 19.3% ESTs to information storage and processing, 11.3% ESTs to posttranslational modification, protein turnover, chaperones, 11.3% ESTs to transport, 9.9% ESTs to signal transducer/cell communication, 9.0% ESTs to structure protein, 3.8% ESTs to cell cycle, and only 6.6% ESTs classified as novel genes. By EST sequencing, a full-length gene coding ferritin was identified and characterized. The recombinant plasmid pET32a-TAT-Ferritin was constructed, coded for the TAT-Ferritin fusion protein with two 6× His-tags in N and C-terminal. After BCA assay, the concentration of soluble Trx-TAT-Ferritin recombinant protein was 2.32 ± 0.12 mg/mL. These results demonstrated that the reliability and representativeness of the cDNA library attained to the requirements of a standard cDNA library. This library provided a useful platform for the functional genome and transcriptome research of Bengal tigers.
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Graphene-patched CNT/MnO2 nanocomposite papers for the electrode of high-performance flexible asymmetric supercapacitors.
ACS Appl Mater Interfaces
PUBLISHED: 04-05-2013
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MnO2 has been widely studied as the pseudo-capactive electrode material of high-performance supercapacitors for its large operating voltage, low cost, and environmental friendliness. However, it suffers from low conductivity and being hardly handle as the electrodes of supercapacitors especially with flexibility, which largely limit its electrochemical performance and application. Herein, we report a novel ternary composite paper composed of reduced graphene sheet (GR)-patched carbon nanotube (CNT)/MnO2, which has controllable structures and prominent electrochemical properties for a flexible electrode of the supercapacitor. The composite paper was prepared by electrochemical deposition of MnO2 on a flexible CNT paper and further adsorption of GR on its surface to enhance the surface conductivity of the electrode and prohibit MnO2 nanospheres from detaching with the electrode. The presence of GR was found remarkably effective in enhancing the initial electrochemical capacitance of the composite paper from 280 F/g to 486.6 F/g. Furthermore, it ensures the stability of the capacitance after a long period of charge/discharge cycles. A flexible CNT/polyaniline/CNT/MnO2/GR asymmetric supercapacitor was assembled with this composite paper as an electrode and aqueous electrolyte gel as the separator. Its operating voltage reached 1.6 V, with an energy density at 24.8 Wh/kg. Such a composite structure derived from a multiscale assembly can offer not only a robust scaffold loading MnO2 nanospheres but also a conductive network for efficient ionic and electronic transport; thus, it is potentially promising as a novel electrode architecture for high-performance flexible energy storage devices.
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Unique drug screening approach for prion diseases identifies tacrolimus and astemizole as antiprion agents.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 04-01-2013
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Prion diseases such as Creutzfeldt-Jakob disease (CJD) are incurable and rapidly fatal neurodegenerative diseases. Because prion protein (PrP) is necessary for prion replication but dispensable for the host, we developed the PrP-FRET-enabled high throughput assay (PrP-FEHTA) to screen for compounds that decrease PrP expression. We screened a collection of drugs approved for human use and identified astemizole and tacrolimus, which reduced cell-surface PrP and inhibited prion replication in neuroblastoma cells. Tacrolimus reduced total cellular PrP levels by a nontranscriptional mechanism. Astemizole stimulated autophagy, a hitherto unreported mode of action for this pharmacophore. Astemizole, but not tacrolimus, prolonged the survival time of prion-infected mice. Astemizole is used in humans to treat seasonal allergic rhinitis in a chronic setting. Given the absence of any treatment option for CJD patients and the favorable drug characteristics of astemizole, including its ability to cross the blood-brain barrier, it may be considered as therapy for CJD patients and for prophylactic use in familial prion diseases. Importantly, our results validate PrP-FEHTA as a method to identify antiprion compounds and, more generally, FEHTA as a unique drug discovery platform.
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Triple pathology in patients with temporal lobe epilepsy: A case report and review of the literature.
Exp Ther Med
PUBLISHED: 03-30-2013
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The coexistence of three intracranial lesions related to epileptic pathogenesis is known as triple pathology and has rarely been reported. In this study we report a case of temporal lobe epilepsy (TLE) with the coexistence of hippocampal sclerosis (HS), focal cortical dysplasia (FCD) and ganglioglioma in the temporal lobe. A 29-year-old male who had experienced recurrent seizures for four years was admitted to hospital. Cerebral magnetic resonance imaging (MRI) was conducted and T2-weighted and fluid-attenuated inversion recovery sequence (FLAIR) images revealed a reduced hippocampal volume with an increased FLAIR signal on the right side and a slightly enlarged temporal horn, which are typical imaging findings for HS and FCD. The patient underwent resectioning of the right anterior temporal lobe, hippocampus and amygdala, in addition to the lesion located in the medial temporal lobe. Immunohistochemical analysis of the medial temporal lobe lesion confirmed a ganglioglioma (WHO grade I) in the medial temporal lobe. During the first eight months following surgery, the patients seizures were controlled with zonisamide and phenytoin. Electroencephalogram (EEG) assessment post-surgery confirmed the absence of epileptic discharges. Based on a literature review and a detailed review of this case, we postulate two possible explanations for the pathogenesis of triple pathology: i) triple pathology is a combination of pathological progression and occasionality; and ii) triple pathology lesions have similar pathological origins.
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CA II, a potential biomarker by proteomic analysis, exerts significant inhibitory effect on the growth of colorectal cancer cells.
Int. J. Oncol.
PUBLISHED: 03-21-2013
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In the Western world, colorectal cancer (CRC) is the third most common cancer with poor prognosis. To identify the proteins and to elucidate the possible mechanisms involved in colorectal carcinogenesis, 2-DE coupled with MS/MS analysis were employed to compare the global protein profile between CRC and individual matched normal tissues from 8 CRC patients. Of 36 proteins identified, carbonic anhydrase II (CA II) was one of most significantly altered and its downregulation in CRC tissues was verified by RT-PCR, western blotting and immunohistochemistry methods, suggesting that CA II may serve as a potential biomarker for CRC diagnosis. To investigate the function and mechanisms of CA II in CRC, a stable SW480 colorectal cancer cell line overexpressing CA II was established. It was shown that overexpression of CA II remarkably suppressed tumor cell growth both in vitro and in vivo, which was in part interpreted by cell cycle arrest at G0/G1 and G2 phase. Further mechanism analysis revealed that the sensitivity of colorectal cancer cells to chemotherapy drugs could be increased by CA II overexpression. Taken together, these data suggest that CA II may be a potential biomarker for early diagnosis of CRC and the results may contribute to a better understanding of the molecular mechanism of CRC and colorectal cancer treatment.
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The MDM2-p53 pathway revisited.
J Biomed Res
PUBLISHED: 03-15-2013
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The p53 tumor suppressor is a key transcription factor regulating cellular pathways such as DNA repair, cell cycle, apoptosis, angiogenesis, and senescence. It acts as an important defense mechanism against cancer onset and progression, and is negatively regulated by interaction with the oncoprotein MDM2. In human cancers, the TP53 gene is frequently mutated or deleted, or the wild-type p53 function is inhibited by high levels of MDM2, leading to downregulation of tumor suppressive p53 pathways. Thus, the inhibition of MDM2-p53 interaction presents an appealing therapeutic strategy for the treatment of cancer. However, recent studies have revealed the MDM2-p53 interaction to be more complex involving multiple levels of regulation by numerous cellular proteins and epigenetic mechanisms, making it imperative to reexamine this intricate interplay from a holistic viewpoint. This review aims to highlight the multifaceted network of molecules regulating the MDM2-p53 axis to better understand the pathway and exploit it for anticancer therapy.
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Identification of metabolites of honokiol in rat urine using 13C stable isotope labeling and liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.
J Chromatogr A
PUBLISHED: 03-09-2013
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A general approach based on stable isotope labeling and UPLC/Q-TOF-MS analysis of in vivo novel metabolites of honokiol has been developed in our study. In this method, urine samples were collected after intravenous administration of mixture of regular and [(13)C6]-labeled honokiol at 1:1 ratio to healthy rats. The metabolites could be easily recognized by the determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to that between isotope-labeled and non-isotope-labeled honokiol. A total of 51 metabolites were detected, 37 of which were tentatively identified based on mass accuracy (<5 ppm). Among them, 33 of honokiol metabolites were first reported with 5 metabolites belonging to phase I and other 32 metabolites belonging to phase II metabolites. Our results highlighted that the main phase I metabolic pathways of honokiol in rats were oxidation, and the phase II metabolic pathways were sulfation, glucuronidation, acetylation as well as amino acids conjugation. This was the first research focused on the biotransformation of honokiol in rats, and the identification of these metabolites might provide us essential information for further pharmacological and clinical studies of honokiol.
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Identification of honokiol metabolites in rats by the method of stable isotope cluster technique and ultra-high performance liquid chromatography/quadrupole-time-of-flight mass spectrometry.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 02-03-2013
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Honokiol, a natural molecule isolated from Magnolia officinalis Rehd. et Wils., is widely known as an antitumor agent. In present work, an analysis of in vivo biotransformation and metabolites of honokiol has been performed by a combined method based on stable isotope cluster technique with honokiol-[(13)C6]-labeled and ultra-high performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC/Q-TOF-MS). The metabolites could be easily identified by the determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to that between isotope-labeled and non-isotope-labeled honokiol. A total of eighteen metabolites were detected and tentatively identified, fourteen of which were reported for the first time. The results indicated that the main metabolic pathways of honokiol in rats were hydroxylation, methylation, sulfation and glucuronidation. This study provided the first essential information on biotransformation and metabolites of honokiol in rats, which was very useful for further pharmacological and clinical studies of honokiol as a potent drug candidate.
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Synthesis and biological evaluation of novel pyranochalcone derivatives as a new class of microtubule stabilizing agents.
Eur J Med Chem
PUBLISHED: 01-02-2013
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Twenty-five novel pyranochalcone derivatives were synthesized and evaluated for their in vitro and in vivo antiproliferative activities. Among them, compound 10i exhibited superior potent activity against 21 tumor cell lines including multidrug resistant phenotype with the IC50 values ranged from 0.09 to 1.30 ?M. In addition, 10i significantly induced cell cycle arrest in G2/M phase, promoted tubulin polymerization into microtubules and caused microtubule stabilization. Further studies confirmed that 10i significantly suppressed the growth of tumor volume in HepG2 xenograft tumor model. Our study demonstrated that 10i could have beneficial antitumor activity as a novel microtubule stabilizing agent.
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Identification of splice variants, targeted microRNAs and functional single nucleotide polymorphisms of the BOLA-DQA2 gene in dairy cattle.
DNA Cell Biol.
PUBLISHED: 11-15-2011
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Major histocompatibility complex, class II, DQ alpha 2, also named BOLA-DQA2, belongs to the Bovine Leukocyte Antigen (BOLA) class II genes which are involved in the immune response. To explore the variability of the BOLA-DQA2 gene and resistance to mastitis in cows, the splice variants (SV), targeted microRNAs (miRNAs), and single nucleotide polymorphisms (SNPs) were identified in this study. A new SV (BOLA-DQA2-SV1) lacking part of exon 3 (195 bp) and two 3-untranslated regions (UTR) (52 bp+167 bp) of the BOLA-DQA2 gene was found in the healthy and mastitis-infected mammary gland tissues. Four of 13 new SNPs and multiple nucleotide polymorphisms resulted in amino acid changes in the protein and SNP (c. +1283 C>T) may affect the binding to the seed sequence of bta-miR-2318. Further, we detected the relative expressions of two BOLA-DQA2 transcripts and five candidated microRNAs binding to the 3-UTR of two transcripts in the mammary gland tissues in dairy cattle by using the quantitative real-time polymerase chain reaction. The result showed that expression of the BOLA-DQA2-SV1 mRNA was significantly upregulated 2.67-fold (p<0.05) in mastitis-infected mammary tissues (n = 5) compared with the healthy mammary gland mammary tissues (n = 5). Except for bta-miR-1777a, miRNA expression (bta-miR-296, miR-2430, and miR-671) was upregulated 1.75 to 2.59-fold (p<0.05), whereas miR-2318 was downregulated in the mastitis cows. Our findings reveal that BOLA-DQA2-SV1 may play an important role in the mastitis resistance in dairy cattle. Whether the SNPs affect the structure of the BOLA-DQA2 gene or association with mastitis resistance is unknown and warrants further investigation.
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Unified Hamiltonian for conducting polymers.
J Phys Condens Matter
PUBLISHED: 10-21-2011
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Two transferable physical parameters are incorporated into the Su-Schrieffer-Heeger Hamiltonian to model conducting polymers beyond polyacetylene: the parameter ? scales the electron-phonon coupling strength in aromatic rings and the other parameter ? specifies the heterogeneous core charges. This generic Hamiltonian predicts the fundamental band gaps of polythiophene, polypyrrole, polyfuran, poly-(p-phenylene), poly-(p-phenylene vinylene), and polyacenes, and their oligomers of all lengths, with an accuracy exceeding time-dependent density functional theory. Its computational costs for moderate-length polymer chains are more than eight orders of magnitude lower than first-principles approaches.
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Changes of the transverse diameter and volume and dosimetry before the 25th fraction during the course of intensity-modulated radiation therapy (IMRT) for patients with nasopharyngeal carcinoma.
Med Dosim
PUBLISHED: 07-23-2011
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To quantify changes of the transverse diameter and volume and dosimetry, and to illustrate the inferiority of non-replanning during intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) patients. Fifty-three NPC patients who received IMRT in 33 fractions were enrolled in this prospective trial. Before the 25th fraction, a new simulation computed tomography (CT) scan was acquired for all patients. The dose-volume histograms of the phantom plan were compared with the initial plan. Significant reduction of the transverse diameter of the nasopharyngeal, the neck, and 2 parotid glands volume was observed on second CT compared with the first CT (mean reduction 7.48 ± 4.45 mm, 6.80 ± 15.14 mm, 5.70 ± 6.26 mL, and 5.04 ± 5.85 mL, respectively; p < 0.01). The maximum dose and V-40 of the spinal cord, mean dose, and V30 of the left and right parotid, and V-50 of the brain stem were increased significantly in the phantom plan compared with the initial plan (mean increase 4.75 ± 5.55 Gy, 7.18 ± 10.07%, 4.51 ± 8.55 Gy, 6.59 ± 17.82%, 5.33 ± 8.55 Gy, 11.68 ± 17.11% and 1.48 ± 3.67%, respectively; p < 0.01). On the basis of dose constraint criterion in the RTOG0225 protocol, the dose of the normal critical structures for 52.83% (28/53) of the phantom plans were out of limit compared with 1.89% (1/53) of the initial plans (p < 0.0001). Because of the significant change in anatomy and dose before the 25th fraction during IMRT, replanning should be necessary during IMRT with NPC.
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Influence of large signal modulation on photonic UWB generation based on electro-optic modulator.
Opt Express
PUBLISHED: 07-13-2011
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Various schemes based on electro-optic modulators have been reported to generate ultra-wideband (UWB) signals in the optical domain, but the availability of these methods always relies on small signal modulation. In this paper, the influence of large signal modulation on two typical schemes, representing two major categories of external-modulator-based photonic UWB generation schemes, is analytically and numerically studied. While the quasi single-sideband UWB (QSSB-UWB) pulse can maintain its shape, the Gaussian UWB (GUWB) generation scheme suffers serious modulation distortion when the phase modulation index is greater than ?/6. The modulation distortion would have negative impact on the receiver sensitivity when the signal is sent to a correlation receiver.
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Alternative splicing and mRNA expression analysis of bovine SLAMF7 gene in healthy and mastitis mammary tissues.
Mol. Biol. Rep.
PUBLISHED: 07-11-2011
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The signaling lymphocyte-activating molecule family 7 (SLAMF7) proteins serve as adhesion molecules on the surface of a variety of mature hematopoietic cells, and also partially control certain innate and adaptive immune responses. We characterized three novel bovine SLAMF7 splice variants, designated as SLAMF7-AS1, AS2, and AS3. All three novel SLAMF7 isoforms are derived from the complete transcripts (SLAMF7-complete) via alternative splicing (AS). The patterns of the three splice variants are exon skipping and alternative 5 splice sites. Bovine SLAMF7 transcripts are expressed in mammary tissue, as demonstrated by real-time PCR. The levels of the complete transcript expression in the normal mammary tissues were higher than that in Staphylococcus aureus (Staph. aureus)-induced mastitis mammary tissues. However, it was not significant for the mRNA expression level comparison between these two kinds of mammary. The SLAMF-AS2 isoforms are expressed the lowest levels among the three transcripts in both normal and infected mammary tissues. This study provides clues for a better understanding of bovine SLAMF7 gene function.
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Using acellular porcine limbal stroma for rabbit limbal stem cell microenvironment reconstruction.
Biomaterials
PUBLISHED: 06-11-2011
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To investigate the feasibility of using acellular porcine limbal stroma for limbal stem cell microenvironment reconstruction. Limbal reconstruction was performed in rabbit partial limbal defect models. Rabbits were randomly divided into four groups: acellular porcine limbal stroma, de-epithelized rabbit limbal autograft stroma, de-epithelized porcine limbal stroma and acellular porcine corneal stroma transplantation groups. In both the acellular porcine limbal stroma and de-epithelized rabbit limbal autograft stroma groups, cornea transparency and epithelium integrity were sustained and graft rejection was not observed. The basal epithelial cells of the grafts showed the K3+/P63+/Ki67+ phenotype at postoperative month 1, but it returned to K3-/P63+/Ki67+(phenotype characteristic of limbal epithelium) by postoperative months 3 and 6. In the de-epithelized porcine limbal stroma group, acute and serious immune rejection occurred by postoperative days 8-10. The basal epithelial cells of the grafts showed the K3+/P63+/Ki67+ phenotype at postoperative month 1. In the acellular porcine corneal stroma group, there were some new vessel invasion into the peripheral cornea and mild corneal opacity. The basal epithelial cells of the grafts showed the K3+/P63+/Ki67+ phenotype at postoperative months 1, 3, and 6. In conclusion, acellular porcine limbal stroma possessed very low immunogenicity, retained a good original limbal ECM microenvironment, and thus the reconstructed rabbit limbal microenvironment maintained limbal epithelial stem cell stemness and proliferation.
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Tectonic lamellar keratoplasty with acellular corneal stroma in high-risk corneal transplantation.
Mol. Vis.
PUBLISHED: 05-16-2011
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Tectonic lamellar keratoplasty (TLKP) is a primary surgical procedure to improve the condition of the recipient bed in high-risk corneal transplantation. It is usually performed for a secondary optical penetrating keratoplasty (PKP). The present study was undertaken to explore a new strategy for TLKP using acellular corneal stroma (ACS) prepared by decellularization.
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Development and validation of a UPLC-MS/MS method for quantification of SKLB010, an investigational anti-inflammatory compound, and its application to pharmacokinetic studies in beagle dogs.
J Pharm Biomed Anal
PUBLISHED: 05-15-2011
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SKLB010 is currently under development as a potential therapeutic agent for the treatment of acute hepatitis and rheumatoid arthritis. The purpose of this paper was to investigate the pre-clinical pharmacokinetics of SKLB010 in beagle dogs. An ultra performance liquid chromatographic tandem mass spectroscopy (UPLC-MS/MS) method was developed and validated for the quantitative determination of SKLB010 in dog plasma, using rosiglitazone as the internal standard (I.S.). Plasma samples were prepared by a simple solid phase extraction (SPE) method. The analyte and internal standard were separated by an Acquity UPLC BEH C18 (2.1 mm × 50 mm) column with a mobile phase of methanol-water (80/20, v/v) over 2 min. Detection was based on the multiple reaction monitoring with the precursor-to-product ion transitions m/z 234.10?147.92 (SKLB010) and m/z 356.15?150.00 (I.S.). The method was validated according to FDA guidelines on bio-analytical method validation. The selectivity, sensitivity, linearity, accuracy, precision, extraction recovery, ion suppression and stability were within the acceptable ranges. The method described above was successfully applied to reveal the single- and multi-pharmacokinetic profiles of SKLB010 in beagle dogs and should be extendable to pharmacokinetic studies in other species as well.
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Carbon nanotube composite films with switchable transparency.
ACS Appl Mater Interfaces
PUBLISHED: 02-25-2011
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A composite film with switchable transparency is fabricated by sandwiching a carbon nanotube (CNT) sheet within polyurethane (PU) films. The introduction of CNTs not only makes the composite film electrically conductive but also induces a rapid crystal melting of soft segments in the PU. As a result, the film can be switched from opaque to transparent in just several seconds after turning on voltage, and reversed back to opaque after turning off voltage. The film also possesses several other attractive properties, including excellent flexibility, low energy consumption, switching speed insensitivity to ambient temperature, and easy coloration, which make the film promising for a wide variety of practical applications.
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Targeting ovarian tumor cell adhesion mediated by tissue transglutaminase.
Mol. Cancer Ther.
PUBLISHED: 02-17-2011
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Tissue transglutaminase (TG2) is a transpeptidase involved in protein cross-linking through generation of ?-(?-glutamyl)lysine isopeptide bonds. It also promotes cell adhesion through interaction with fibronectin and facilitates formation of fibronectin-integrin complexes. This interaction is involved in tumor cell adhesion to the matrix and in the process of tumor dissemination. Its inhibition by small molecules may therefore be useful in blocking metastasis. To that end, we screened more than 800,000 compounds following an in silico docking approach targeting two distinct cavities in the vicinity of the fibronectin-binding site on TG2. A total of 120 compounds were acquired and tested in cell culture-based assays for inhibition of ovarian tumor cell adhesion and proliferation. Seven compounds showed more than 50% inhibition of cell adhesion at a concentration of 25 ?mol/L. A follow-up fluorescence polarization study revealed that one compound in particular (ITP-79) inhibited binding of a TG2 peptide to a 42-kDa fragment of fibronectin in a dose-dependent manner. This inhibition was confirmed in cancer cells by coimmunoprecipitation. A competition assay with surface plasmon resonance showed that ITP-79 modulated binding of TG2 to fibronectin. Direct binding of compounds that inhibited adhesion to TG2 were examined with differential scanning fluorimetry, which measures the effect of the compound on the melting temperature of the target. Two compounds, including ITP-79, reduced TG2 stabilization, mimicking the effects of GTP, a known negative allosteric regulator of TG2 enzymatic function. This suggests a potential allosteric mechanism for the compound in light of its distal target site.
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Rapidly constructed scaffold-free cornea epithelial sheets for ocular surface reconstruction.
Tissue Eng Part C Methods
PUBLISHED: 02-14-2011
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To develop a centrifugal cell seeding method for rapid and efficient reconstruction of ocular surface with limbal stem cell deficiency (LSCD) in rabbits.
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Solexa sequencing of novel and differentially expressed microRNAs in testicular and ovarian tissues in Holstein cattle.
Int. J. Biol. Sci.
PUBLISHED: 01-30-2011
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The posttranscriptional gene regulation mediated by microRNA plays an important role in the development and function of male and female reproductive organs and germ cells in mammals, including cattle. In the present study, we identified novel and differentially expressed miRNAs in the testis and ovary in Holstein cattle by combining the Solexa sequencing with bioinformatics. In total 100 and 104 novel pre-miRNAs were identified in testicular and ovarian tissues, encoding 122 and 136 mature miRNAs, respectively. Of these, 6 miRNAs appear to be bovine-specific. A total of 246 known miRNAs were co-expressed in the testicular and ovarian tissues. Of the known miRNAs, twenty-one testis-specific and nine ovary-specific (1-23 reads) were found. Approximately 30.5% of the known bovine miRNAs in this study were found to have >2-fold differential expression within the two respective reproductive organ systems. The putative miRNA target genes of miRNAs were involved in pathways associated with reproductive physiology. Both known and novel tissue-specific miRNAs are expressed by Real-time quantitative PCR analysis in dairy cattle. This study expands the number of miRNAs known to be expressed in cattle. The patterns of miRNAs expression differed significantly between the bovine testicular and ovarian tissues, which provide important information on sex differences in miRNA expression. Diverse miRNAs may play an important regulatory role in the development of the reproductive organs in Holstein cattle.
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PDGF induced microRNA alterations in cancer cells.
Nucleic Acids Res.
PUBLISHED: 01-25-2011
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Platelet derived growth factor (PDGF) regulates gene transcription by binding to specific receptors. PDGF plays a critical role in oncogenesis in brain and other tumors, regulates angiogenesis, and remodels the stroma in physiologic conditions. Here, we show by using microRNA (miR) arrays that PDGFs regulate the expression and function of miRs in glioblastoma and ovarian cancer cells. The two PDGF ligands AA and BB affect expression of several miRs in ligand-specific manner; the most robust changes consisting of let-7d repression by PDGF-AA and miR-146b induction by PDGF-BB. Induction of miR-146b by PDGF-BB is modulated via MAPK-dependent induction of c-fos. We demonstrate that PDGF regulates expression of some of its known targets (e.g. cyclin D1) through miR alterations and identify the epidermal growth factor receptor (EGFR) as a new PDGF-BB target. We show that its expression and function are repressed by PDGF-induced miR-146b and that mir-146b and EGFR correlate inversely in human glioblastomas. We propose that PDGF-regulated gene transcription involves alterations in non-coding RNAs and provide evidence for a miR-dependent feedback mechanism balancing growth factor receptor signaling in cancer cells.
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A proteomic investigation into adriamycin chemo-resistance of human leukemia K562 cells.
Mol. Cell. Biochem.
PUBLISHED: 01-10-2011
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This study aimed to explore the mechanism of adriamycin resistance in human chronic myelogenous leukemia cells. Proteomic approach was utilized to compare and identify differentially expressed proteins between human chronic myelogenous leukemia K562 cells and their adriamycin-resistant counterparts. The differentially expressed proteins were analyzed by 2-DE (two-dimensional gel electrophoresis), and protein identification were performed on ESI-Q-TOF MS/MS instrument. Out of the 35 differentially expressed proteins between the two cell lines, 29 were identified and grouped into 10 functional classes. Most of identified proteins were related to the categories of metabolism (24%), proteolysis (13%), signal transduction (21%) and calcium ion binding (6%), suggesting that alterations of those biological processes might be involved in adriamycin resistance of K562 cells. We believe this study may provide some clues to a better understanding of the molecular mechanisms underlying adriamycin resistance.
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Double-peak mechanical properties of carbon-nanotube fibers.
Small
PUBLISHED: 10-14-2010
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The introduction of twist during the spinning of carbon nanotubes from their arrays (forests) has been widely applied in making ultrastrong, stiff, and lightweight nanotube fibers. Here, for the first time, an important observation of a double-peak behavior of the tensile properties, as a function of the twist angle, that is different from the single peak of traditional fibers is reported. Raman spectra show that the new peak arises from the collapse of nanotubes, showing a strong "nano" element in applying the ancient draw-and-twist technique, besides the downsizing. A qualitative continuum model is also presented to describe the collapse-induced enhancement as well as traditional fibers. Our combined experimental and theoretical studies indicate the direction of full utilization of the nano element in improving the mechanical properties of nanotube fibers.
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Kinetics of hexagonal cylinders to face-centered cubic spheres transition of triblock copolymer in selective solvent: Brownian dynamics simulation.
J Chem Phys
PUBLISHED: 09-07-2010
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The kinetics of the transformation from the hexagonal packed cylinder (hex) phase to the face-centered-cubic (fcc) phase was simulated using Brownian dynamics for an ABA triblock copolymer in a selective solvent for the A block. The kinetics was obtained by instantaneously changing either the temperature of the system or the well-depth of the Lennard-Jones potential. Detailed analysis showed that the transformation occurred via a rippling mechanism. The simulation results indicated that the order-order transformation was a nucleation and growth process when the temperature of the system instantly jumped from 0.8 to 0.5. The time evolution of the structure factor obtained by Fourier transformation showed that the peak intensities of the hex and fcc phases could be fit well by an Avrami equation.
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Acidic hyaluronidase activity is present in mouse sperm and is reduced in the absence of SPAM1: evidence for a role for hyaluronidase 3 in mouse and human sperm.
Mol. Reprod. Dev.
PUBLISHED: 06-30-2010
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The molecular mechanisms underlying sperm penetration of the physical barriers surrounding the oocyte have not been completely delineated. Although neutral-active or "reproductive" hyaluronidases (hyases), exemplified by Sperm Adhesion Molecule 1 (SPAM1), are thought to be responsible for hyaluronan digestion in the egg vestments and for sperm-zona binding, their roles in mouse sperm have been recently questioned. Here we report that acidic "somatic" Hyaluronidase 3 (HYAL3), a homolog of SPAM1 with 74.6% structural similarity, exists in two isoforms in human ( approximately 47 and approximately 55 kDa) and mouse ( approximately 44 and approximately 47 kDa) sperm, where it resides on the plasma membrane over the head and midpiece. Mouse isoforms are differentially distributed in the soluble (SAP), membrane (MBP), and acrosome-reacted (AR) fraction where they are most abundant. Comparisons of zymography of Hyal3 null and wild-type (WT) AR and MBP fractions show significant HYAL3 activity at pH 3 and 4, and less at pH 7. At pH 4, a second acid-active hyase band at approximately 57 kDa is present in the AR fraction. HYAL3 activity was confirmed using immunoprecipitated HYAL3 and spectrophotometry. In total proteins, hyase activity was higher at pH 6 than at 4, where Spam1 nulls had significantly (P < 0.01) diminished activity implicating an acidic optima for murine SPAM1. Although fully fertile, Hyal3 null sperm showed delayed cumulus penetration and reduced acrosomal exocytosis. HYAL3 is expressed in epididymal tissue/fluid, from where it is acquired by caudal mouse sperm in vitro. Our results reveal concerted activity of both neutral- and acid-active hyaluronidases in sperm.
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Proteomic analysis of interstitial fluid in bone marrow identified that peroxiredoxin 2 regulates H(2)O(2) level of bone marrow during aging.
J. Proteome Res.
PUBLISHED: 06-24-2010
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Hematopoiesis in bone marrow declines during aging owing to alteration of the hematopoietic niche. However, due to difficult accessibility and other complexities, senescence-related alteration of the hematopoietic niche is largely unknown. The interstitial fluid of bone marrow (IFBM), a pivotal component of the hematopoietic niche, includes soluble secretory factors that are present between bone marrow cells. To characterize the proteomic profile changes of IFBM during aging, we analyzed the IFBMs of young, adult, and senescent rats using 2-DE combined with ESI/MALDI-Q-TOF MS. Finally, 31 differentially expressed proteins involved in multiple biological functions were identified. Peroxiredoxin 2 (Prx2), down-regulated during aging, was further analyzed and demonstrated that it is produced by bone marrow stromal cells. Interestingly, higher levels of hydrogen peroxide (H(2)O(2)) were detected in the bone marrow with lower Prx2 expression. Moreover, exogenous Prx2 reduced the intracellular H(2)O(2) level in bone marrow stromal cells in vitro. Therefore, Prx2 is implied in the regulation of H(2)O(2) production in the bone marrow during aging. Our data characterized the dynamic protein profiles of the bone marrow microenvironment during aging and we provided clues to elucidate the mechanism of creating a low ROS level in the hematopoietic niche.
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Predictable and linear scale-up of four phenolic alkaloids separation from the roots of Menispermum dauricum using high-performance counter-current chromatography.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 04-18-2010
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This paper describes how distribution ratios were used for prediction of peak elution in analytical high-performance counter-current chromatography (HPCCC) to explore the method for separation and purification of bioactive compounds from the roots of Menispermum dauricum. Then important parameters related to HPCCC separations including solvent systems, sample concentration, sample loading volume and flow rate were optimized on an analytical Mini-DE HPCCC and finally linearly scaled up to a preparative Midi-DE HPCCC with nearly the same resolutions and separation time. Four phenolic alkaloids were for the first time obtained by HPCCC separation with a two-phase solvent system composed of petroleum ether-ethyl acetate-ethanol-water (1:2:1:2, v/v). This process produced 131.3 mg daurisolin, 197.1 mg dauricine, 32.4 mg daurinoline and 14.7 mg dauricicoline with the purity of 97.6%, 96.4%, 97.2% and 98.3%, respectively from 500 mg crude extract of the roots of M. dauricum in a one-step separation. The purities of compounds were determined by high-performance liquid chromatography (HPLC). Their structures were identified by electrospray ionization mass spectrometer (ESI-MS) and nuclear magnetic resonance (NMR).
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Concordant genetic distinctness of the phylogroup of the Siberian chipmunk from the Korean peninsula (Tamias sibiricus barberi), reexamined with nuclear DNA c-myc gene exon 2 and mtDNA control region sequences.
Biochem. Genet.
PUBLISHED: 03-29-2010
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We reexamined Tamias sibiricus barberi from Korea by sequencing c-myc exon 2 and the mtDNA control region. In the c-myc exon, the monogenic T. s. barberi differed from the monogenic T. s. orientalis (nucleotide distance 0.48%; 3 variable sites at 168, 306, and 552), whereas T. s. orientalis was identical to T. s. sibiricus. In the control region, T. s. barberi differed from T. s. orientalis (distance 6.84%) and T. s. sibiricus (9.35%). We considered the concordant, extensive gaps between the phylogroup of T. s. barberi and other subspecies of T. sibiricus in the c-myc gene, control region, and cytochrome b gene to be evidence of a lack of intergradation through North Korea from T. s. barberi to T. s. orientalis. Our results, showing the genetic and morphological distinctness of T. s. barberi, support that this phylogroup is a distinct species.
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Preparative isolation and purification of anti-tumor agent ansamitocin P-3 from fermentation broth of Actinosynnema pretiosum using high-performance counter-current chromatography.
J Sep Sci
PUBLISHED: 03-18-2010
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Ansamitocin P-3 is a potent anti-tumor maytansinoid found in Actinosynnema pretiosum. However, due to the complexity of the fermentation broth of Actinomycete, how to effectively separate ansamitocin P-3 is still a challenge. In this study, both analytical and preparative high-performance counter-current chromatography were successfully used to separate and purify ansamitocin P-3 from fermentation broth. A total of 28.8 mg ansamitocin P-3 with purity of 98.4% was separated from 160 mg crude sample of fermentation broth in less than 80 min with the two-phase solvent system of hexane-ethyl acetate-methanol-water (0.6:1:0.6:1, v/v/v/v). The purity and structural identification were determined by HPLC, (1)H NMR, (13)C NMR and mass spectroscopy.
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Enrichment and isolation of barbigerone from Millettia pachycarpa Benth. using high-speed counter-current chromatography and preparative HPLC.
J Sep Sci
PUBLISHED: 02-27-2010
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Enrichment of the anti-tumor compound barbigerone along with a rotenoid derivative from Millettia pachycarpa Benth. was performed by a two-step high-speed counter-current chromatography (HSCCC) separation process. In the first step, 155.8 mg of target fraction (Fra6) was obtained from 400 mg ethyl acetate extract of M. pachycarpa Benth. with an increase in barbigerone from 5.1 to 13% via HSCCC using a solvent system of n-hexane-ethyl acetate-methanol-water (5:4:5:3, v/v) under normal phase head to tail elution. HSCCC was repeated to eliminate the major contaminant in this initial fraction 6. After a separation time of 65 min, 22.1 mg barbigerone of 87.7% purity was obtained from Fra6 with the ternary solvent system of n-hexane-methanol-water (2:2:1, v/v) under normal phase elution. Finally, preparative HPLC was employed for the further isolation of barbigerone and the rotenoid derivative. The structures were confirmed by ESI-MS, (1)H NMR and (13)C NMR.
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Honokiol inhibits HepG2 migration via down-regulation of IQGAP1 expression discovered by a quantitative pharmaceutical proteomic analysis.
Proteomics
PUBLISHED: 02-04-2010
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Honokiol (HNK), a natural small molecular product, inhibited proliferation of HepG2 cells and exhibited anti-tumor activity in nude mice. In this article, we applied a novel sensitive stable isotope labeling with amino acids in cell culture-based quantitative proteomic method and a model of nude mice to investigate the correlation between HNK and the hotspot migration molecule Ras GTPase-activating-like protein (IQGAP1). The quantitative proteomic analysis showed that IQGAP1 was 0.53-fold down-regulated under 10 microg/mL HNK exposure for 24 h on HepG2 cells. Migration ability of HepG2 cells under HNK treatment was correlated with its expression level of IQGAP1. In addition, the biochemical validation on HepG2 cells and the tumor xenograft model further demonstrated that HNK decreased the expression level of IQGAP1 and its upstream proteins Cdc42/Rac1. These data supported that HNK can modulate cell adhesion and cell migration by acting on Cdc42/Rac1 signaling via IQGAP1 interactions with its upstream Cdc42/Rac1 proteins, which is a new molecular mechanism of HNK to exert its anti-tumor activity.
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Proteomics-based approach identified differentially expressed proteins with potential roles in endometrial carcinoma.
Int. J. Gynecol. Cancer
PUBLISHED: 01-09-2010
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INSTRUCTION: We used proteomic approaches to identify altered expressed proteins in endometrial carcinoma, with the aim of discovering potential biomarkers or therapeutic targets for endometrial carcinoma.
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[The improved design of table operating box of digital subtraction angiography device].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 12-02-2009
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In this paper are analyzed the disadvantages of CGO-3000 digital subtraction angiography table Operating Box. The authors put forward a communication control scheme between single-chip microcomputer(SCM) and programmable logic controller(PLC). The details of hardware and software of communication are given.
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Epithelial-to-mesenchymal transition and ovarian tumor progression induced by tissue transglutaminase.
Cancer Res.
PUBLISHED: 12-01-2009
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Tissue transglutaminase (TG2), an enzyme that catalyzes Ca(2+)-dependent aggregation and polymerization of proteins, is overexpressed in ovarian cancer cells and tumors. We previously reported that TG2 facilitates tumor dissemination using an i.p. xenograft model. Here we show that TG2 modulates epithelial-to-mesenchymal transition (EMT), contributing to increased ovarian cancer cell invasiveness and tumor metastasis. By using stable knockdown and overexpression in epithelial ovarian cancer cells, we show that TG2 induces a mesenchymal phenotype, characterized by cadherin switch and invasive behavior in a Matrigel matrix. This is mediated at the transcriptional level by altering the expression levels and function of several transcriptional repressors, including Zeb1. One mechanism through which TG2 induces Zeb1 is by activating the nuclear factor-kappaB complex. The effects of TG2 on ovarian cancer cell phenotype and invasiveness translate into increased tumor formation and metastasis in vivo, as assessed by an orthotopic ovarian xenograft model. Highly expressed in ovarian tumors, TG2 promotes EMT and enhances ovarian tumor metastasis by activating oncogenic signaling.
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Rapid separation and identification of major constituents in Pseudolarix kaempferi by ultra-performance liquid chromatography coupled with electrospray and quadrupole time-of-flight tandem mass spectrometry.
Rapid Commun. Mass Spectrom.
PUBLISHED: 11-18-2009
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A rapid and reliable method based on ultra-performance liquid chromatography (UPLC) coupled with photodiode-array detection (PDA) and electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF-MS/MS) has been developed for separation and identification of major constituents in extracts of root bark of Pseudolarix kaempferi Gordon (PKG). Identification of the constituents was carried out by interpretation of their retention times, UV absorption spectra, MS and MS/MS spectra, as well as the data provided by authentic standards and literatures. A total of 20 components were separated in only 8.0 min on a small particle size C18 column (1.7 microm). These components included nine diterpene acids, seven glycosides and four triterpenoids, among which pseudolaric acid C-O-beta-D-glucopyranoside and pseudolaric acid C2-O-beta-D-glucopyranoside were separated and identified for the first time in this study. Furthermore, the fragmentation patterns of the three types of compounds were elucidated for the first time. This established UPLC-PDA/Q-TOF-MS/MS method is reliable and effective for the separation and identification of the 20 compounds and will be useful for quality control of the crude materials of Pseudolarix kaempferi Gordon and their related preparations.
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Weekly paclitaxel with concurrent radiotherapy followed by adjuvant chemotherapy in locally advanced nasopharyngeal carcinoma.
Radiother Oncol
PUBLISHED: 06-09-2009
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To evaluate the efficacy and toxicity of weekly paclitaxel with concurrent radiotherapy followed by adjuvant chemotherapy (AC) in patients with locally advanced nasopharyngeal carcinoma (NPC).
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2, 3, 5, 4-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG) induces melanogenesis in B16 cells by MAP kinase activation and tyrosinase upregulation.
Life Sci.
PUBLISHED: 05-23-2009
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The 2, 3, 5, 4-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG), a water-soluble active component extracted from dried tuber root of Polygonum multiflorum, has been found to induce pigmentation in B16 cells, but the details of the underlying mechanism remain unknown. The present study was conducted to investigate the mechanism of stimulatory effect of THSG on melanogenesis using B16F1 melanoma cells.
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Single nucleotide polymorphisms, haplotypes and combined genotypes of lactoferrin gene and their associations with mastitis in Chinese Holstein cattle.
Mol. Biol. Rep.
PUBLISHED: 05-18-2009
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Lactoferrin (Lf) is naturally produced by the mammary gland, having biological functions of antibacterial and anti-inflammatory activities. To investigate whether the Lf gene is associated with mastitis in dairy cattle, a DNA sequencing approach was used to identify single nucleotide polymorphisms (SNPs) in the gene. Three previously reported SNPs in the 5 flanking region and one novel SNP in exon1 of Lf gene were identified. A total of 353 individuals from Holstein cattle populations were genotyped for their SNPs using Created Restriction Site PCR (CRS-PCR) and PCR-RFLP methods. Twenty-two and nineteen combinations of three SNPs (g.3440T>G, g.3879_3880insG, and g.4432T>C) and another three SNPs (g.3429G>A, g.3440T>G, g.3879_3880insG) were observed, respectively. The result of haplotype analysis of four SNPs showed that fourteen different haplotypes were identified. Two major haplotypes (GECB and GECA) occurred with a frequency of 22.5 and 18.5% in the study population, respectively. Statistical analyses revealed no significant association between one single SNP of Lf gene and SCS, whereas significant associations between their combined genotypes of three SNPs, haplotype and SCS. Combined genotype EFCDBB and GGEFDD with the lowest SCS were favorable for the mastitis resistance. They may be used as a possible candidate for marker-assisted selection in dairy cattle breeding program.
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Mechanism of cancer cell adaptation to metabolic stress: proteomics identification of a novel thyroid hormone-mediated gastric carcinogenic signaling pathway.
Mol. Cell Proteomics
PUBLISHED: 04-02-2009
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Gastric cancer is the second most common cancer worldwide and has a poor prognosis. To determine the mechanism of adaptation to metabolic stress in cancer cells, we used gastric cancer as a model system to reveal the potential signaling pathways involved. Two-dimensional polyacrylamide gel electrophoresis coupled with ESI-Q-TOF MS/MS analysis was used to identify differentially expressed proteins between gastric tumor tissues and the corresponding noncancerous tissues. In total, 107 spots with significant alteration (+/-over 2-fold, p < 0.05) were positively identified by MS/MS analysis. Altered expression of representative proteins was validated by RT-PCR and Western blotting. Cluster analysis of the changed proteins revealed an interesting group of metabolic proteins, which suggested accumulation of triiodothyronine (T(3); the major functional component of thyroid hormone) and overexpression of hypoxia-induced factor (HIF) in gastric carcinoma. These observations were further confirmed by electrochemiluminescence immunoassay and immunohistochemistry. T(3)-induced expression of HIF1-alpha and vascular endothelial growth factor was further verified using a gastric cancer cell line and in vivo mouse model. Because the early accumulation of HIF1-alpha was found to be independent of de novo transcription, we also found that the cytosolic cascade phosphatidylinositol 3-kinase/Akt pathway sensitive to T(3) stimulus was involved. Furthermore we demonstrated that T(3)-induced overexpression of HIF1-alpha was mediated by fumarate accumulation and could be enhanced by fumarate hydratase inactivation but inhibited by 2-oxoglutarate. These results provide evidence for alteration of metabolic proteins and dysfunction of thyroid hormone regulation in gastric tumors, and a novel thyroid hormone-mediated tumorigenic signaling pathway is proposed. Our findings are considered a significant step toward a better understanding of adaptations to metabolic stress in gastric carcinogenesis.
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Simultaneous normal and parallel incidence planar left-handed metamaterial.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 03-26-2009
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We investigate numerically the negative refraction of a simultaneous normal and parallel incidence planar left-handed metamaterial (LHM) in this paper. This LHM is comprised of fourfold C-shaped rings, which are printed on both sides of the substrates symmetrically, and it can exhibit left-handed properties with electromagnetic wave incident in three different directions. The retrieved result and the simulated result verify the left-handed properties of the fourfold C-shaped metamaterial very well. Then the different electric responses of the normal and parallel incidence cases to the incident electromagnetic wave are discussed, and it is due to the different distribution of the induced currents in the metallic wires.
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Tissue transglutaminase regulates matrix metalloproteinase-2 in ovarian cancer by modulating cAMP-response element-binding protein activity.
J. Biol. Chem.
PUBLISHED: 03-26-2009
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Tissue transglutaminase 2 (TG2) is overexpressed in epithelial ovarian cancer (EOC) and promotes intraperitoneal metastasis. How TG2 facilitates the spread of EOC is unknown. Here, we show that TG2 regulates the expression and function of matrix metalloproteinase-2 (MMP-2), a critical mediator of tissue invasiveness. TG2 knockdown down-regulates MMP-2 protein and mRNA expression in SKOV3, IGROV-1, MDA-MB-436, and PC-3 cancer cells. TG2 knockdown or inhibition of TG2 activity using KCC009 decreases MMP-2 gelatinase activity in cancer cells. MMP-2 expression and function are regulated by TG2 at transcriptional level, as demonstrated by quantitative PCR and reporter assays. We used bioinformatics and chromatin immunoprecipitation to identify a CREB binding site in the MMP-2 promoter. Binding of CREB to the MMP-2 promoter was diminished in cells that expressed decreased TG2 levels. TG2 knockdown decreased CREB phosphorylation, and CREB knockdown decreased MMP-2 expression. The effect of TG2 on CREB activity and MMP-2 transcription is mediated by TG2-dependent degradation of protein phosphatase 2 (PP2A-alpha). We show that PP2A-alpha complexes with and is targeted for degradation by TG2. In addition to their related in vitro expression levels, TG2 and MMP-2 expression were significantly correlated in vivo, as shown by concordant immunostaining in peritoneal xenografts and in human ovarian tumors. The capacity of TG2 to regulate MMP-2 expression in vitro and in vivo identifies a mechanism that may facilitate tissue invasion and the spread of EOC. The demonstration that TG2 induced degradation of PP2A-alpha activates CREB, and thereby increases MMP-2 transcription, provides novel mechanistic insight into the pro- metastatic function of TG2.
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Kinetics of p-nitrophenol adsorption by layered double oxides during its hydration.
Water Environ. Res.
PUBLISHED: 03-14-2009
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Kinetics of p-nitrophenol (PNP) adsorption onto layered double oxides (LDO) during its hydration into layered double hydroxides (LDH) was studied. Results indicate that the adsorption of PNP onto LDO is a spontaneous endothermic process. The adsorption isotherms correlate well with the Freundlich type model. Results suggest that the adsorption of PNP onto LDO is an entropy-increasing process, and it appears to be in agreement with pseudo-second-order kinetics. Intra-particle diffusion was found to take part in the adsorption processes, and it might be the primary rate-limiting step for the sorbing capacity of LDO to PNP. Results from X-ray diffraction and Fourier transform infrared indicate that PNP molecules are probably taken into the interlayer of the structure during the hydration of LDO into the LDH. Activated carbon was used as a benchmark material in evaluating the sorbing capacity of LDO to PNP. The sorbing capacity of LDO to PNP (32 mg PNP/g LDO) was well below activated carbon (659 mg PNP/g carbon); however, the sorbing process of LDO to PNP is also a unique synthetic process for LDH, which has been used in removing specific anionic species, such as bioagents and pharmaceutical intermediates from waters.
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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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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.