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Find video protocols related to scientific articles indexed in Pubmed.
Exposure to Brefeldin A promotes initiation of meiosis in murine female germ cells.
Reprod. Fertil. Dev.
PUBLISHED: 02-09-2015
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In mammals, ontogenesis starts from a fusion of spermatozoon and oocyte, which are produced by reductive nuclear division of a diploid germ cell in a specialised but complex biological process known as meiosis. However, little is known about the mechanism of meiotic initiation in germ cells, although many factors may be responsible for meiosis both in male and female gonads. In this study, 11.5 days post coitum (dpc) female fetal mouse genital ridges were cultured in vitro with exposure to Brefeldin A (BFA) for 6h, and the changes in meiosis were detected. Synaptonemal-complex analysis implied that BFA played a positive role in meiosis initiation and this hypothesis was confirmed by quantitative PCR of meiosis-specific genes: stimulated by retinoic acid gene 8 (Stra8) and deleted in a zoospermia-like (DAZL). At the same time, mRNA expression of retinoic acid synthetase (Raldh2) and retinoic acid (RA) receptors increased in female gonads with in vitro exposure to BFA. Transplanting genital ridges treated with BFA into the kidney capsule of immunodeficient mice demonstrated that the development capacity of female germ cells was normal, while formation of primordial follicles was seen to be a result of accelerated meiosis after exposure to BFA. In conclusion, the study indicated that BFA stimulated meiosis initiation partly by RA signalling and then promoted the development of follicles.
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A Chemical Tuned Strategy to Develop Novel Irreversible EGFR-TK Inhibitors with Improved Safety and Pharmacokinetic Profiles.
J. Med. Chem.
PUBLISHED: 11-20-2014
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Gatekeeper T790M mutation in EGFR is the most prevalent factor underlying acquired resistance. Acrylamide-bearing quinazoline derivatives are powerful irreversible inhibitors for overcoming resistance. Nevertheless, concerns about the risk of non-specific covalent modification have motivated the development of novel cysteine-targeting inhibitors. In this paper, we demonstrate that fluoro-substituted olefins can be tuned to alter Michael addition reactivity. Incorporation of these olefins into the quinazoline templates produced potent EGFR inhibitors with improved safety and pharmacokinetic properties. A lead compound 5a was validated against EGFRWT, EGFR T790M as well as A431 and H1975 cancer cell lines. Additionally, compound 5a displayed a weaker inhibition against the EGFR-independent cancer cell line SW620 when compared withafatinib. Oral administration of 5a at a dose of 30mg/kg induced tumor regression in a murine-EGFRL858R/T790M driven H1975 xenograft model. Also, 5a exhibited improved oral bioavailability and safety, as well as favorable tissue distribution properties and enhanced brain uptake. These findings provide the basis of a promising strategy toward the treatment of NSCLC patients with drug resistance.
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Long-Term Safety and Efficacy of Factor IX Gene Therapy in Hemophilia B.
N. Engl. J. Med.
PUBLISHED: 11-20-2014
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Background In patients with severe hemophilia B, gene therapy that is mediated by a novel self-complementary adeno-associated virus serotype 8 (AAV8) vector has been shown to raise factor IX levels for periods of up to 16 months. We wanted to determine the durability of transgene expression, the vector dose-response relationship, and the level of persistent or late toxicity. Methods We evaluated the stability of transgene expression and long-term safety in 10 patients with severe hemophilia B: 6 patients who had been enrolled in an initial phase 1 dose-escalation trial, with 2 patients each receiving a low, intermediate, or high dose, and 4 additional patients who received the high dose (2×10(12) vector genomes per kilogram of body weight). The patients subsequently underwent extensive clinical and laboratory monitoring. Results A single intravenous infusion of vector in all 10 patients with severe hemophilia B resulted in a dose-dependent increase in circulating factor IX to a level that was 1 to 6% of the normal value over a median period of 3.2 years, with observation ongoing. In the high-dose group, a consistent increase in the factor IX level to a mean (±SD) of 5.1±1.7% was observed in all 6 patients, which resulted in a reduction of more than 90% in both bleeding episodes and the use of prophylactic factor IX concentrate. A transient increase in the mean alanine aminotransferase level to 86 IU per liter (range, 36 to 202) occurred between week 7 and week 10 in 4 of the 6 patients in the high-dose group but resolved over a median of 5 days (range, 2 to 35) after prednisolone treatment. Conclusions In 10 patients with severe hemophilia B, the infusion of a single dose of AAV8 vector resulted in long-term therapeutic factor IX expression associated with clinical improvement. With a follow-up period of up to 3 years, no late toxic effects from the therapy were reported. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT00979238 .).
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Bridging silicon nanoparticles and thermoelectrics: phenylacetylene functionalization.
Faraday Discuss.
PUBLISHED: 11-20-2014
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Silicon is a promising alternative to current thermoelectric materials (Bi2Te3). Silicon nanoparticle based materials show especially low thermal conductivities due to their high number of interfaces, which increases the observed phonon scattering. The major obstacle with these materials is maintaining high electrical conductivity. Surface functionalization with phenylacetylene shows an electrical conductivity of 18.1 S m(-1) and Seebeck coefficient of 3228.8 ?V K(-1) as well as maintaining a thermal conductivity of 0.1 W K(-1) m(-1). This gives a ZT of 0.6 at 300 K which is significant for a bulk silicon based material and is similar to that of other thermoelectric materials such as Mg2Si, PbTe and SiGe alloys.
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Development of a genetic transformation system for Candida tropicalis based on a reusable selection marker of URA3 gene.
Yi Chuan
PUBLISHED: 11-20-2014
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Candida tropicalis, a diploid asporogenic yeast, is frequently utilized in industrial applications and research studies. However, the low efficiency of genetic transformation limits the strain improvement by metabolic engineering. A reliable transformation and efficient deletion of target gene are prerequisite for molecular improvement of C. tropicalis. In this study, an efficient approach for genetic transformation of C. tropicalis was developed based on the URA3 gene as a reusable selection marker and both of PDC allele genes encoding pyruvate decarboxylase were successfully deleted by this approach. Firstly, an auxotrophic mutant strain of C. tropicalis XZX which is defective in orotidine-5'-phosphate decarboxylase (URA3) was isolated by chemical mutagenesis combined with nystatin enrichment selection and 5-fluoro-orotic acid (5-FOA) resistance selection using C. tropicalis ATCC 20336 as the parent strain. Then, the first PDC deletion cassette PDC1-hisG-URA3-hisG- PDC1 (PHUHP) which contains a 1.6 kb URA3 marker gene, two copies of 1.1 kb Salmonella hisG fragments and homologous arms of target gene was constructed and transformed into C. tropicalis XZX cells. Transformants with a single copy of PDC deleted were isolated and identified by PCR and DNA sequencing, which was designated as C.tropicalis XZX02. The C.tropicalis XZX02 cells were spread on the minimal medium containing 5-FOA to generate mutant C. tropicalis XZX03 in which URA3 marker gene was excised from PHUHP fragment integrated into the PDC gene site. The second PDC gene deletion cassette PDCm-URA3-PDCm (MUM) was constructed and transformed into C. tropicalis XZX03 to generate C.tropicalis XZX04 in which both of PDC allele genes were deleted. All strains were confirmed by PCR and DNA sequencing. This efficient genetic transformation approach laid a foundation for further metabolic engineering of C. tropicalis.
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Control Performance of Paper-based Blood Analysis Devices through Paper Structure Design.
ACS Appl Mater Interfaces
PUBLISHED: 11-19-2014
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In this work, we investigated the influence of paper structure on the performance of paper-based analytical devices that are used for blood analysis. The question that we aimed to answer is how the fibre type (i.e., softwood and hardwood fibres) influences the fibre network structure of the paper, which affects the transport of red blood cells (RBCs) in paper. In the experimental design, we isolated the influence of fibre types on the paper structure from all other possible influencing factors by removing the fines from the pulps and not using any additives. Mercury porosimetry was employed to characterize the pore structures of the paper sheets. The results show that papers with a low basis weight that are made with short hardwood fibres have a higher porosity (i.e., void fraction) and simpler pore structures compared with papers made with long softwood fibres. RBC transport in paper carried by saline solution was investigated in two modes: lateral chromatographic elution and vertical flow-through. The results showed that the complexity of the paper's internal pore structure has dominant influence on the transport of RBCs in paper. Hardwood fibre sheets with a low basis weight have a simple internal pore structure and allow for the easy transport of RBCs. Blood typing sensors built with low basis weight hardwood fibres deliver high-clarity assays. Softwood fibre papers are found to have a more complex pore structure, which makes RBC transport more difficult, leading to blood typing results of low clarity. This study provides the principle of paper sheet design for paper-based blood analysis sensors.
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Understanding Thread Properties for Red Blood Cells Antigen Assays: Weak ABO Blood Typing.
ACS Appl Mater Interfaces
PUBLISHED: 11-18-2014
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"Thread-based microfluidics" research has so far focused on utilizing and manipulating the wicking properties of threads to form controllable microfluidic channels. In this study we aim to understand the separation properties of threads, which are important to their microfluidic detection applications for blood analysis. Confocal microscopy was utilised to investigate the effect of the micro-scale surface morphologies of fibres on the thread's separation efficiency of red blood cells. We demonstrated the remarkably different separation properties of threads made using silk and cotton fibres. Thread separation properties dominate the clarity of blood typing assays of the ABO groups and some of their weak subgroups (Ax and A3). The microfluidic thread-based analytical devices designed were used to accurately type different blood samples, including 89 normal ABO and 6 weak A subgroups. By selecting thread with the right surface morphology, we were able to build ?TADs capable of providing rapid and accurate typing of the weak blood groups with high clarity.
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Inhibitors of HGFA, Matriptase, and Hepsin Serine Proteases: A Nonkinase Strategy to Block Cell Signaling in Cancer.
ACS Med Chem Lett
PUBLISHED: 11-13-2014
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Hepatocyte growth factor activators (HGFA), matriptase, and hepsin are S1 family trypsin-like serine proteases. These proteases proteolytically cleave the single-chain zymogen precursors, pro-HGF (hepatocyte growth factor), and pro-MSP (macrophage stimulating protein) into active heterodimeric forms. HGF and MSP are activating ligands for the oncogenic receptor tyrosine kinases (RTKs), c-MET and RON, respectively. We have discovered the first substrate-based ketothiazole inhibitors of HGFA, matriptase and hepsin. The compounds were synthesized using a combination of solution and solid-phase peptide synthesis (SPPS). Compounds were tested for protease inhibition using a kinetic enzyme assay employing fluorogenic peptide substrates. Highlighted HGFA inhibitors are Ac-KRLR-kt (5g), Ac-SKFR-kt (6c), and Ac-SWLR-kt (6g) with K is = 12, 57, and 63 nM, respectively. We demonstrated that inhibitors block the conversion of native pro-HGF and pro-MSP by HGFA with equivalent potency. Finally, we show that inhibition causes a dose-dependent decrease of c-MET signaling in MDA-MB-231 breast cancer cells. This preliminary investigation provides evidence that HGFA is a promising therapeutic target in breast cancer and other tumor types driven by c-MET and RON.
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The Discovery and Optimization of 4,5-Diarylisoxazoles as Potent Dual Inhibitors of Pyruvate Dehydrogenase Kinase (PDHK) and Heat Shock Protein 90 (HSP90).
J. Med. Chem.
PUBLISHED: 11-11-2014
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Upregulation of pyruvate dehydrogenase kinase (PDHK) has been observed in a variety of cancers. Inhibition of PDHK offers an attractive opportunity for the development of novel cancer therapies. To obtain novel PDHK inhibitors, we took advantage of the homology of the ATP-binding pocket between HSP90 and PDHK, and utilized 4,5-diarylisoxazole based HSP90 inhibitor for structural design. Our efforts led to the identification of 5k that inhibited PDHK1 with an IC50 value of 17 nM, which however, showed marginal cellular activity. Further structural optimization resulted in compound 11a with improved cellular activity which could effectively modulate the metabolic profile of cancer cells and led to the inhibition of cancer cell proliferation, evidenced by the increased oxidative phosphorylation and decreased glycolysis and associated oxidative stress. Our results suggested 11a as an excellent lead compound and a favorable biological tool to further evaluate the therapeutic potential of PDHK and HSP90 dual inhibitors in the treatment of cancer.
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Strained olefin enables triflic anhydride mediated direct dehydrative glycosylation.
Org. Biomol. Chem.
PUBLISHED: 11-05-2014
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For the first time, we demonstrated that Tf2O mediated direct dehydrative glycosylation was possible simply with strained olefins, and other typical bases were inhibitors of this reaction. We optimized the glycosylation conditions and found that typical benzyl protected 1-OH pyranosyl donors and certain alcohol acceptors were suitable for our glycosylation system. Furthermore, we found that complete 1,2-trans selectivity and a wider acceptor scope could be achieved with 2-O-Bz 3,4,6-tri-O-Bn pyranosyl donors.
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Field testing the ENSEMBLE Minimum Dataset: performance of an instrument to address heterogeneity of treatment effects.
J Comp Eff Res
PUBLISHED: 10-29-2014
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To assess the ability of ENterprising SElective Multi-instrument BLend for hEterogeneity analysis (ENSEMBLE) Minimum Dataset instrument dimensions to discriminate among subgroups of patients expected to have differential outcomes.
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Barcode-like paper sensor for smartphone diagnostics: an application of blood typing.
Anal. Chem.
PUBLISHED: 10-27-2014
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This study introduced a barcode-like design into a paper-based blood typing device by integrating with smartphone-based technology. The concept of presenting a paper-based blood typing assay in a barcode-like pattern significantly enhanced the adaptability of the assay to the smartphone technology. The fabrication of this device involved the use of a printing technique to define hydrophilic bar channels which were, respectively, treated with Anti-A, -B, and -D antibodies. These channels were then used to perform blood typing assays by introducing a blood sample. Blood type can be visually identified from eluting lengths in bar channels. A smartphone-based analytical application was designed to read the bar channels, analogous to scanning a barcode, interpret this information, and then report results to users. The proposed paper-based blood typing device is rapidly read by smartphones and easy for the user to operate. We envisage that the adaptation of paper-based devices to the widely accepted smartphone technology will increase the capability of paper-based diagnostics with rapid assay result interpretation, data storage, and transmission.
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Carbon quantum dots and their applications.
Chem Soc Rev
PUBLISHED: 10-16-2014
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Fluorescent carbon nanoparticles or carbon quantum dots (CQDs) are a new class of carbon nanomaterials that have emerged recently and have garnered much interest as potential competitors to conventional semiconductor quantum dots. In addition to their comparable optical properties, CQDs have the desired advantages of low toxicity, environmental friendliness low cost and simple synthetic routes. Moreover, surface passivation and functionalization of CQDs allow for the control of their physicochemical properties. Since their discovery, CQDs have found many applications in the fields of chemical sensing, biosensing, bioimaging, nanomedicine, photocatalysis and electrocatalysis. This article reviews the progress in the research and development of CQDs with an emphasis on their synthesis, functionalization and technical applications along with some discussion on challenges and perspectives in this exciting and promising field.
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Antiphospholipid antibodies attenuate endothelial repair and promote neointima formation in mice.
J Am Heart Assoc
PUBLISHED: 10-16-2014
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Antiphospholipid syndrome patients have antiphospholipid antibodies (aPLs) that promote thrombosis, and they have increased cardiovascular disease risk. Although the basis for the thrombosis has been well delineated, it is not known why antiphospholipid syndrome patients also have an increased prevalence of nonthrombotic vascular occlusion. The aims of this work were to determine if aPLs directly promote medial hypertrophy or neointima formation in mice and to identify the underlying mechanisms.
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Exogenous thymine DNA glycosylase regulates epigenetic modifications and meiotic cell cycle progression of mouse oocytes.
Mol. Hum. Reprod.
PUBLISHED: 10-09-2014
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In mammalian cells, 5-methylcytosine (5-meC) can be transformed into 5-hydroxymethylcytosine (5-hmC) by the methylcytosine dioxygenase TET proteins (TET1, TET2 and TET3). Thymine DNA glycosylase (TDG), a downstream enzyme of TET proteins, not only functions in base excision repair, but also acts as a key enzyme that participates in active DNA demethylation. Here we microinjected exogenous TDG-mCherry mRNAs into germinal vesicle (GV) stage mouse oocytes, and found that initially TDG-mCherry localized in the nucleus. Just before GV breakdown (GVBD), TDG-mCherry was released from the nucleus into the cytoplasm. In contrast with TDG, another active DNA demethylation-associated enzyme, activation-induced cytidine deaminase (AID) became localized in the cytoplasm of GV oocytes, but entered the nucleus of oocytes just before GVBD. However, both TDG and AID could enter the G0 stage nuclei of cumulus cells injected into the ooplasm. To analyze the effects of TDG on oocyte maturation, we over-expressed TDG-mCherry in GV oocytes, and found that the rates of both GVBD and polar body extrusion rate were significantly decreased. When the TDG over-expressed oocytes were blocked at the GV stage, the oocyte chromatin became decondensed, and the histone 3 trimethyl lysine 9 (H3K9me3) and H3K9me2 levels were decreased. We also found that TDG could reduce the 5-meC level of oocyte genomic DNA. All these results indicate that aberrant TDG expression causes epigenetic modifications and meiotic cell cycle arrest of mouse oocytes.
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Influence of Duschinsky and Herzberg-Teller effects on S?? S? vibrationally resolved absorption spectra of several porphyrin-like compounds.
J Chem Phys
PUBLISHED: 10-03-2014
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The S0 ? S1 (Q band) high-resolved absorption spectra of three porphyrin-like compounds, porphycene, magnesium porphyrin, and zinc tetraazaporphyrin, were simulated in the framework of the Franck-Condon approximation including the Duschinsky and Herzberg-Teller (HT) contributions. Substitution of meso-aza on porphyrin macrocycle framework could change severely the absorption energy, vibrational intensity, and spectral profile of Q band. Therefore, we focused attention on the spectral similarities and contrasts among the three compounds based on the density functional theory and its time-dependent extension calculations. The simulated spectra agreed well with the experimental ones and further confirmed that the HT and Duschinsky effects have significant influence on the weakly allowed or forbidden transition of sizable organic molecules. The pure HT and Duschinsky effects were explored separately to clarify their contributions on changing vibrational intensities of different modes. Moreover, we tentatively assigned most of the vibrational modes which appeared in the experimental spectra but corresponding assignments were not given. The present work provided a useful method to simulate and interpret the absorption spectra of porphyrin-like compounds.
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Lack of Impact of Mild Obstructive Sleep Apnea on Sleepiness, Mood and Quality of Life.
Southwest J Pulm Crit Care
PUBLISHED: 09-19-2014
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Obstructive sleep apnea (OSA) is associated with sleepiness, depression and reduced quality of life. However, it is unclear whether mild OSA has these negative impacts. Using data from the Apnea Positive Pressure Long-term Efficacy Study (APPLES), this study determined whether participants with mild OSA had greater sleepiness, more depressive symptoms and poorer quality of life in comparison to those without OSA.
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Effects of substance P on growth of fibroblast-like cells derived from bile duct: an in vitro cell culture study.
Chin. Med. J.
PUBLISHED: 09-06-2014
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The possible role of substance P (SP) during wound healing has been the primary research focus in recent years, but its effect on the healing process after bile duct injury is little understood. This study aimed to investigate the effects of SP on growth of fibroblast-like cells derived from rabbit bile duct.
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[Effect of intermittent hypoxia on lipid metabolism in liver cells and the underlying mechanism].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 09-03-2014
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To determine the effect of intermittent hypoxia on lipid metabolism in liver cells and to explore the possible molecular pathways involved in this process.
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Theoretical study on the chemical mechanism of enoyl-CoA hydratase and the form of inhibitor binding.
J Mol Model
PUBLISHED: 09-02-2014
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Enoyl-CoA hydratase (ECH) catalyzes the second step in the vital ?-oxidation pathway of fatty acid metabolism. This enzyme catalyzes the syn-addition of a water molecule across the double bond of 4-(N,N-dimethylamino) cinnamoyl-CoA (DAC-CoA). In this work, the reaction mechanisms of ECH were investigated using the density functional theory (DFT) methods. The different protonation states in which the important residues Glu164 and Glu144 are either neutral or ionized were considered. Four models of the active site were designed based on the X-ray crystal structure of the enzyme. The calculations gave strong support to the proposed mechanism and confirmed that both Glu164 and Glu144 are in a deprotonated state in the reaction mechanism of ECH. In addition, we constructed a model of the active site with the inhibitor acetoacetyl-CoA based on the crystal structure. Caomparison of the calculated energy barriers showed that binding of the keto-enol form of the inhibitor is more reasonable than that of the di-keto form in the inhibition process. Moreover, acetoacetyl-CoA was found to exhibit a keto-enol tautomerism when it acts as an inhibitor in the reaction. The present theoretical results indicated that both residues Glu164 and Glu144 are unprotonated in ECH with the substrate bound, while only Glu164 is unprotonated when the inhibitor binds ECH.
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Discovery of potent N-(isoxazol-5-yl)amides as HSP90 inhibitors.
Eur J Med Chem
PUBLISHED: 08-26-2014
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HSP90 is ubiquitously overexpressed in a broad spectrum of human cancers and has been recognized as an attractive target for cancer treatment. Here, we described the fragment screening, synthesis and structure-activity relationship studies of small molecule inhibitors with 4,5-diarylisoxazole scaffold targeting HSP90. Among them, the compound N-(3-(2,4-dihydroxy-5-isopropylphenyl)-4-(4-((4-morpholinopiperidin-1-yl)methyl)phenyl)isoxazol-5-yl)cyclopropanecarboxamide (108) showed high affinity for binding to HSP90 (FP binding assay, IC50 = 0.030 ?M) and inhibited the proliferation of various human cancer cell lines with averaging GI50 about 88 nM. Compound 108 exhibited its functional inhibition of HSP90 by depleting key signaling pathways and concomitantly elevating of HSP70 and HSP27 in U-87MG cells. Further in vivo studies showed that compound 108 strongly suppressed the tumor growth of human glioblastoma xenograft model U-87MG with T/C = 18.35% at 50 mg/kg q3w/2.5w. Moreover, compound 108 also exhibited good pharmacokinetic properties. Together, our study implicates that compound 108 is a promising candidate of HSP90 inhibitor and is currently advanced to preclinical study.
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Molecules and mechanisms controlling the active DNA demethylation of the mammalian zygotic genome.
Protein Cell
PUBLISHED: 08-26-2014
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The active DNA demethylation in early embryos is essential for subsequent development. Although the zygotic genome is globally demethylated, the DNA methylation of imprinted regions, part of repeat sequences and some gamete-specific regions are maintained. Recent evidence has shown that multiple proteins and biological pathways participate in the regulation of active DNA demethylation, such as TET proteins, DNA repair pathways and DNA methyltransferases. Here we review the recent understanding regarding proteins associated with active DNA demethylation and the regulatory networks controlling the active DNA demethylation in early embryos.
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Molecular Genetic Biomarkers in Myeloid Malignancies.
Arch. Pathol. Lab. Med.
PUBLISHED: 08-25-2014
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Context .- Recent studies using massively parallel sequencing technologies, so-called next-generation sequencing, have uncovered numerous recurrent, single-gene variants or mutations across the spectrum of myeloid malignancies. Objectives .- To review the recent advances in the understanding of the molecular basis of myeloid neoplasms, including their significance for diagnostic and prognostic purposes and the possible implications for the development of novel therapeutic strategies. Data Sources .- Literature review. Conclusions .- The recurrent mutations found in myeloid malignancies fall into distinct functional categories. These include (1) cell signaling factors, (2) transcription factors, (3) regulators of the cell cycle, (4) regulators of DNA methylation, (5) regulators of histone modification, (6) RNA-splicing factors, and (7) components of the cohesin complex. As the clinical significance of these mutations and mutation combinations is established, testing for their presence is likely to become a routine part of the diagnostic workup. This review will attempt to establish a framework for understanding these mutations in the context of myeloproliferative neoplasms, myelodysplastic syndromes, and acute myeloid leukemia.
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Anti-tumor drug delivery system based on cyclodextrin-containing pH-responsive star polymer: in vitro and in vivo evaluation.
Int J Pharm
PUBLISHED: 08-19-2014
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A cyclodextrin-containing pH-responsive star polymer, with cyclodextrin polymer and pH-sensitive poly(2-(dimethylamino)ethyl methacrylate) as the core and poly(ethylene glycol) as the arm, was evaluated as drug carriers in vitro and in vivo. Doxorubicin (DOX) was successfully loaded into the star polymer to form nanoparticles (DOX-NPs) via host-guest interaction. The physicochemical properties such as drug loading content, size, morphology, stability and physical state of DOX-NPs were characterized in detail by (1)H NMR, DLS, SEM and DSC. Uniform and stable DOX-NPs with high encapsulation efficiency of 77.1% were obtained, and they also exhibited sustainable and controllable release of DOX in vitro. The cellular uptake of DOX-NPs was in concentration-, time- and cell type-dependent manners, and the cytotoxicity of DOX-NPs was significantly high toward HeLa and HepG2 cancer cells. Furthermore, in vivo anti-tumor experiment on BALB/c mice bearing cervical tumor showed that DOX-NPs could effectively suppress the growth of tumor without significant side effect. These findings suggest that the cyclodextrin-containing pH-responsive star polymer has a promising potential in developing novel drug delivery system for cancer therapy.
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Computational study on the effects of substituent and heteroatom on physical properties and solar cell performance in donor-acceptor conjugated polymers based on benzodithiophene.
J Mol Model
PUBLISHED: 08-16-2014
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Computationally driven material design has attracted increasing interest to accelerate the search for optimal conjugated donor materials in bulk heterojunction organic solar cells. A series of novel copolymers containing benzo[1,2-b:4,5-b']dithiophene (BDT) and thieno[3,4-c]pyrrole-4,6-dione (TPD) derivatives were simulated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). We performed a systematic study on the influences on molecular geometry parameters, electronic properties, optical properties, photovoltaic performances, and intermolecular stacking as well as hole mobility when different chalcogenophenes in TPD derivatives were used and functional groups with different electron-withdrawing abilities such as alkyl, fluorine, sufonyl, and cyano were introduced to the nitrogen positions in electron-deficient units. The substitution position of electron-withdrawing groups may cause little steric hindrance to the neighboring donor units, especially fluorine and cyano group. It was found that the incorporation of these new electron-deficient substituents and sulfur-selenium exchange can be applicable to further modify and optimize existing molecular structures. Our findings will provide valuable guidance and chemical methodologies for a judicious material design of conjugated polymers for solar cell applications with desirable photovoltaic characteristics.
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Synthesis and Biological Evaluation of 2-Phenoxyacetamide Analogues, a Novel Class of Potent and Selective Monoamine Oxidase Inhibitors.
Molecules
PUBLISHED: 08-11-2014
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Monoamine oxidases (EC 1.4.3.4; MAOs), a family of FAD-containing enzymes, is an important target for antidepressant drugs. In this paper, a series of 2-phenoxyacetamide analogues were synthesized, and their inhibitory potency towards monoamine oxidases A (MAO-A) and B (MAO-B) were evaluated using enzyme and cancer cell lysate. 2-(4-Methoxyphenoxy)acetamide (compound 12) (SI = 245) and (2-(4-((prop-2-ynylimino)methyl)phenoxy)acetamide (compound 21) (IC50MAO-A = 0.018 ?M, IC50MAO-B = 0.07 ?M) were successfully identified as the most specific MAO-A inhibitor, and the most potent MAO-A/-B inhibitor, respectively. The inhibitory activities of these two compounds in living cells were also further evaluated utilizing HepG2 and SHSY-5Y cell lysates.
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MDM2 oncogene, E3 ubiquitin protein ligase T309G polymorphism and risk of oesophageal or gastric cancer: meta-analysis of 15 studies.
J. Int. Med. Res.
PUBLISHED: 07-28-2014
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To investigate the association between potentially functional MDM2 oncogene, E3 ubiquitin protein ligase (MDM2) T309G polymorphism and susceptibility to oesophageal or gastric cancer.
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Transcription regulation mechanisms of bacteriophages: Recent advances and future prospects.
Bioengineered
PUBLISHED: 07-24-2014
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Phage diversity significantly contributes to ecology and evolution of new bacterial species through horizontal gene transfer. Therefore, it is essential to understand the mechanisms underlying phage-host interactions. After initial infection, the phage utilizes the transcriptional machinery of the host to direct the expression of its own genes. This review presents a view on the transcriptional regulation mechanisms of bacteriophages, and its contribution to phage diversity and classification. Through this review, we aim to broaden the understanding of phage-host interactions while providing a reference source for researchers studying the regulation of phage transcription.
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Adaptive immunity to murine skin commensals.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 07-07-2014
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The adaptive immune system provides critical defense against pathogenic bacteria. Commensal bacteria have begun to receive much attention in recent years, especially in the gut where there is growing evidence of complex interactions with the adaptive immune system. In the present study, we observed that commensal skin bacteria are recognized by major populations of T cells in skin-draining lymph nodes of mice. Recombination activating gene 1 (Rag1)(-/-) mice, which lack adaptive immune cells, contained living skin-derived bacteria and bacterial sequences, especially mycobacteria, in their skin-draining lymph nodes. T cells from skin-draining lymph nodes of normal mice were shown, in vitro, to specifically recognize bacteria of several species that were grown from Rag1(-/-) lymph nodes. T cells from skin-draining lymph nodes, transferred into Rag1(-/-) mice proliferated in skin-draining lymph nodes, expressed a restricted T-cell receptor spectrotype and produced cytokines. Transfer of T cells into Rag1(-/-) mice had the effect of reducing bacterial sequences in skin-draining lymph nodes and in skin itself. Antibacterial effects of transferred T cells were dependent on IFN? and IL-17A. These studies suggest a previously unrecognized role for T cells in controlling skin commensal bacteria and provide a mechanism to account for cutaneous infections and mycobacterial infections in T-cell-deficient patients.
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Biohydrogen facilitated denitrification at biocathode in bioelectrochemical system (BES).
Bioresour. Technol.
PUBLISHED: 07-03-2014
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Reductive removal of nitrate in bioelectrochemical system (BES) at abiotic cathode, biocathode and biohydrogen facilitated biocathode were investigated. It was found that nitrate removal efficiency reached 95% and 59% at the biohydrogen facilitated biocathode and biocathode respectively, while which was only 13% at the abiotic cathode. Meanwhile, activity of nitrate reductase reached 0.701 g-N/Lh for the biohydrogen facilitated group, which was about 9.3 times of the biocathode group. Moreover, electrochemical performances as power density, ohmic resistance, and polarization resistance of the biohydrogen facilitated group reached 76.96 mW/m(3), 8.63 ohm and 383 ohm, respectively, which were better than two other groups. Finally, an obvious shift of bacterial community responsible for the enhanced nitrate reduction between the two biocathode groups was observed. Therefore, nitrate reduction in BES could be enhanced at the biocathode than that of the abiotic cathode, and then be further boosted with the combination of biohydrogen.
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SnRK1 phosphorylation of AL2 delays Cabbage leaf curl virus infection in Arabidopsis.
J. Virol.
PUBLISHED: 07-02-2014
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Geminivirus AL2/C2 proteins play key roles in establishing infection and causing disease in their plant hosts. They are involved in viral gene expression, counter host defenses by suppressing transcriptional gene silencing, and interfere with the host signaling involved in pathogen resistance. We report here that begomovirus and curtovirus AL2/C2 proteins interact strongly with host geminivirus Rep-interacting kinases (GRIKs), which are upstream activating kinases of the protein kinase SnRK1, a global regulator of energy and nutrient levels in plants. We used an in vitro kinase system to show that GRIK-activated SnRK1 phosphorylates recombinant AL2/C2 proteins from several begomoviruses and to map the SnRK1 phosphorylation site to serine-109 in the AL2 proteins of two New World begomoviruses: Cabbage Leaf Curl Virus (CaLCuV) and Tomato mottle virus. A CaLCuV AL2 S109D phosphomimic mutation did not alter viral DNA levels in protoplast replication assays. In contrast, the phosphomimic mutant was delayed for symptom development and viral DNA accumulation during infection of Arabidopsis thaliana, demonstrating that SnRK1 contributes to host defenses against CaLCuV. Our observation that serine-109 is not conserved in all AL2/C2 proteins that are SnRK1 substrates in vitro suggested that phosphorylation of viral proteins by plant kinases contributes to the evolution of geminivirus-host interactions.
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Neoglycopeptide synthesis by suzuki-miyaura couplings between glycosyl aryl boronic acids and iodopeptides.
Protein Pept. Lett.
PUBLISHED: 07-01-2014
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Suzuki-Miyaura coupling reaction was applied in the syntheses of neoglycopeptides. This work utilizes new type of glycosyl aryl boronic acid and readily accessible iodo amino acids/iodopeptides. Both carbohydrate and peptide moieties are unprotected and the final product could be isolated directly. The neoglyco amino acid and neoglycopeptide products feature an O-glycosyl biaryl linker between the carbohydrate and peptide moieties.
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A novel strategy for preparing glycopeptide molecular probe using fluorous technology.
Protein Pept. Lett.
PUBLISHED: 07-01-2014
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A novel and convenient strategy for iodine labeled glycopeptide molecular probe and purification was developed. The fluorine rich bi-functional coupling agent, 4-tris(2-perfluorohexylethyl)stannylbenzoate succinimidyl ester, was successfully synthesized via 5 steps starting from the fluorous Grignard reagent. It was purified by a simple and fast isolation using perfluorinated hexanes (FC-72). The "cold" iodine labeled yield for the coupling agent was as high as 92% within 15 min. The iodine-labeled product was only in organic fractions as we expected. It was shown that there was only one major peak in organic fractions according to HPLC. Finally, the iodine-labeled coupling agent was applied to label glycopeptide and afforded a high yield of 87% within 30 min.
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Molecular cloning and functional characterization of the NFIL3/E4BP4 transcription factor of grass carp, Ctenopharyngodon idella.
Dev. Comp. Immunol.
PUBLISHED: 06-30-2014
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NFIL3 (nuclear factor interleukin 3-regulated) is an important bZIP transcription factor in the immune response and immune cells' development. Here, we identified the NFIL3 gene from grass carp (Ctenopharyngodon idella; gcNFIL3). The deduced amino acid sequence of gcNFIL3 is 468 residues with a typical bZIP domain. Phylogenetics demonstrated that gcNFIL3 clustered closely with NFIL3 of zebrafish. Real-time PCR revealed gcNFIL3 is constitutively expressed in all tissues examined. Its expression was significantly upregulated in head kidney and trunk kidney after stimulation by bacteria. Immunofluorescence microscopy revealed that gcNFIL3 is mainly expressed in the nucleus. Overexpression of gcNFIL3 reduces Aeromonas hydrophila invasion and proliferation. In CIK cells, gcNFIL3 could induce the activation of NF-kappa B and upregulates the expression of IL10 and IFN. These results indicated that gcNFIL3 has immunoregulatory properties and might play a role in the immune response of fish.
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Upregulation of hepatic VLDLR via PPAR? is required for the triglyceride-lowering effect of fenofibrate.
J. Lipid Res.
PUBLISHED: 06-04-2014
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The liver and the VLDL receptor (VLDLR) play major roles in TG and VLDL metabolism. However, the exact role of liver VLDLR is not well known because of the absence of or difficulty in detecting VLDLR in the liver. In this study, we demonstrate that fenofibrate, a PPAR? agonist and widely used TG-lowering drug, markedly upregulated hepatic VLDLR, which is essential for lowering TG. This study also shows that the distinct regulatory roles of PPAR? agonists on VLDLR in the liver and peripheral tissues including adipose tissues, heart, and skeletal muscles are due to the pattern of expression of PPAR?. The in vivo portion of our study demonstrated that oral fenofibrate robustly increased liver VLDLR expression levels in hyperlipidemic and diabetic mice and significantly reduced the increase in serum TG observed in wt mice after feeding with high-fat diet (HFD) but not in Vldlr(-/-) mice or Ppar?(-/-) mice. However, overexpression of mouse VLDLR in livers of Vldlr(-/-) mice significantly prevented the increase in serum TG induced by HFD. The in vitro portion of our study showed that fenofibrate upregulated VLDLR transcriptional activity through PPAR response element binding to the VLDLR promoter. The conclusions of our study provide a novel mechanism for the TG-lowering effects of fenofibrate in the treatment of dyslipidemia.
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Psychometric properties of the osteoporosis patient assessment questionnaire (OPAQ) 2.0: results from the multiple outcomes of raloxifene evaluation (MORE) study.
BMC Musculoskelet Disord
PUBLISHED: 05-21-2014
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We explored psychometric properties of the Osteoporosis Patient Assessment Questionnaire 2.0 in terms of reliability, validity, and responsiveness with generic, clinical, demographic, and preference-based data collected from a population of postmenopausal women with osteoporosis.
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Characterization of an N-glycosylated Bacillus subtilis leucine aminopeptidase expressed in Pichia pastoris.
J. Basic Microbiol.
PUBLISHED: 05-09-2014
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Aminopeptidase is an important flavorsome especially in protein hydrolysate debittering by removing hydrophobic amino acid residue at the N-terminal end. Besides, it is also applied to preparation of active peptides and analysis of protein sequence. In this study, leucine aminopeptidase from Bacillus subtilis was cloned and expressed in Pichia pastoris, a widely used heterologous protein expression host. Then it was purified and characterized. After methanol induction for 96?h, the aminopeptidase activity in culture supernatant reached 28.4?U?ml(-1) , which was 7.1 times that of wild strain B. subtilis Zj016. The optimal temperature and pH of the purified recombinant enzyme were 60?°C and 8.5, respectively. The purified aminopeptidase was stable within 30-60?°C and pH 8.0-9.0. It was intensively inhibited by Ni(2+) , Ca(2+) , DL-dithiothreitol (DTT) and ethylene diamine tetraacetic acid (EDTA), but activated by Co(2+) . The Km toward leucine-p-nitroanilines (Leu-pNA) of the enzyme was 0.97?mM. The sequence analysis of aminopeptidase indicated three potential N-glycosylation sites and it was further verified via MALDI-TOF-MS analysis. Consequently, the N-glycosylated aminopeptidase exhibited higher thermostability and catalytic efficiency. The purified enzyme exhibited two bands through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) while a single band can be identified when the enzyme was deglycosylated. Circular dichroism spectroscopy indicated that the secondary structure of recombinant aminopeptidase was similar to the wild-type.
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Wireless esophageal pH capsule for patients with gastroesophageal reflux disease: A multicenter clinical study.
World J. Gastroenterol.
PUBLISHED: 05-05-2014
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To investigate the feasibility and safety of pH capsule to monitor pH in patients with gastroesophageal reflux disease (GERD).
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Assessing model fit in joint models of longitudinal and survival data with applications to cancer clinical trials.
Stat Med
PUBLISHED: 04-22-2014
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Joint models for longitudinal and survival data now have a long history of being used in clinical trials or other studies in which the goal is to assess a treatment effect while accounting for longitudinal assessments such as patient-reported outcomes or tumor response. Compared to using survival data alone, the joint modeling of survival and longitudinal data allows for estimation of direct and indirect treatment effects, thereby resulting in improved efficacy assessment. Although global fit indices such as AIC or BIC can be used to rank joint models, these measures do not provide separate assessments of each component of the joint model. In this paper, we develop a novel decomposition of AIC and BIC (i.e., AIC?=?AICLong +?AICSurv|Long and BIC?=?BICLong +?BICSurv|Long ) that allows us to assess the fit of each component of the joint model and in particular to assess the fit of the longitudinal component of the model and the survival component separately. Based on this decomposition, we then propose ?AICSurv and ?BICSurv to determine the importance and contribution of the longitudinal data to the model fit of the survival data. Moreover, this decomposition, along with ?AICSurv and ?BICSurv , is also quite useful in comparing, for example, trajectory-based joint models and shared parameter joint models and deciding which type of model best fits the survival data. We examine a detailed case study in mesothelioma to apply our proposed methodology along with an extensive set of simulation studies. Copyright © 2014 John Wiley & Sons, Ltd.
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Proteomics reveals potential non-neuronal cholinergic receptor-effectors in endothelial cells.
Acta Pharmacol. Sin.
PUBLISHED: 03-31-2014
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The non-neuronal acetylcholine system (NNAS) in endothelial cells participates in modulating endothelial function, vascular tone, angiogenesis and inflammation, thus plays a critical role in cardiovascular diseases. In this study, we used a proteomic approach to study potential downstream receptor-effectors of NNAS that were involved in regulating cellular function in endothelial cells.
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Genetically shaping morphology of the filamentous fungus Aspergillus glaucus for production of antitumor polyketide aspergiolide A.
Microb. Cell Fact.
PUBLISHED: 03-31-2014
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For filamentous fungi, the basic growth unit of hyphae usually makes it sensitive to shear stress which is generated from mechanical force and dynamic fluid in bioreactor, and it severely decreases microbial productions. The conventional strategies against shear-sensitive conundrum in fungal fermentation usually focus on adapting agitation, impeller type and bioreactor configuration, which brings high cost and tough work in industry. This study aims to genetically shape shear resistant morphology of shear-sensitive filamentous fungus Aspergillus glaucus to make it adapt to bioreactor so as to establish an efficient fermentation process.
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Bortezomib for chronic relapsing thrombotic thrombocytopenic purpura: a case report.
Transfusion
PUBLISHED: 03-24-2014
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Acquired thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder characterized by a severe deficiency of ADAMTS13 activity. Although therapeutic plasma exchange (PLEX) is the standard of care, 30% to 50% patients develop exacerbation or relapse, requiring immunomodulatory agents. Of these agents, glucocorticoids, rituximab, and cyclosporine?A are the most frequently used.
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1,2-trans-1-Dihydroxyboryl benzyl S-glycoside as glycosyl donor.
Carbohydr. Res.
PUBLISHED: 03-16-2014
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Activated by NBS, readily available 1,2-trans-1-dihydroxyboryl benzyl S-glycosides served as glycosyl donors and reacted with certain simple alcohol acceptors to produce pure 1,2-cis-O-glycosides in moderate yields. The boronic acid moiety was revealed essential in the glycosylation for product formation and good anomeric ratio. The preliminary model reactions suggested that glycosyl aryl boronic acids could be used for stereoselective glycosylation.
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Relationships between VEGF protein expression and pathological characteristics of diffuse large B cell lymphoma: a meta-analysis.
Tumour Biol.
PUBLISHED: 03-14-2014
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We carried out the current meta-analysis of relevant cohort studies in an attempt to investigate the relationships between vascular endothelial growth factor (VEGF) expression and pathological characteristics of diffuse large B cell lymphoma (DLBCL). The following electronic databases were searched for relevant articles without any language restrictions: Web of Science (1945?~?2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966?~?2013), EMBASE (1980?~?2013), CINAHL (1982?~?2013), and the Chinese Biomedical Database (CBM) (1982?~?2013). Meta-analyses were conducted with the use of STATA software (version 12.0, Stata Corporation, College Station, TX, USA). Odds ratios (ORs) and its 95 % confidence interval (95 % CI) were calculated. Nine clinical cohort studies with a total of 789 DLBCL patients met our inclusion criteria. The meta-analysis results showed that patients with positive VEGF expression had higher international prognostic index (IPI) scores than VEGF-negative patients (OR?=?5.12, 95 % CI?=?2.70?~?9.71, P?
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Metabolic engineering of Escherichia coli for improving shikimate synthesis from glucose.
Bioresour. Technol.
PUBLISHED: 03-02-2014
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Shikimate is a key intermediate for the synthesis of the neuraminidase inhibitors. Microbial production of shikimate and related derivatives has the benefit of cost reduction when compared to traditional methods. In this study, an overproducing shikimate Escherichia coli strain was developed by rationally engineering certain metabolic pathways. To achieve this, the shikimate pathway was blocked by deletion of shikimate kinases and quinic acid/shikimate dehydrogenase. EIICB(glc) protein involved in the phosphotransferase system, and acetic acid pathway were also removed to increase the amount of available phosphoenolpyruvate and decrease byproduct formation, respectively. Thereafter, three critical enzymes of mutated 3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP) synthase (encoded by aroG(fbr)), PEP synthase (encoded by ppsA), and transketolase A (encoded by tktA) were modularly overexpressed and the resulting recombinant strain produced 1207 mg/L shikimate in shake flask cultures. Using the fed-batch process, 14.6g/L shikimate with a yield of 0.29 g/g glucose was generated in a 7-L bioreactor.
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Carvedilol attenuates 6-hydroxydopamine-induced cell death in PC12 cells: involvement of Akt and Nrf2/ARE pathways.
Neurochem. Res.
PUBLISHED: 02-27-2014
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Oxidative stress is closely related to the pathogenesis of neurodegenerative disorders such as Parkinson's disease. Carvedilol, a nonselective ?-adrenergic receptor blocker with pleiotropic activity has been shown to exert neuroprotective effect due to its antioxidant property. However, the neuroprotective mechanism of carvedilol is still not fully uncovered. The phosphotidylinositol 3-kinase (PI3K)/Akt signaling pathway plays key role in cell survival and the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway is the major cellular defense mechanism against oxidative stress. Here we investigated the effects of carvedilol on 6-hydroxydopamine (6-OHDA)-induced cell death as well as the Akt and Nrf2/ARE pathways in PC12 cells. We found that carvedilol significantly increased cell viability and decreased reactive oxygen species in PC12 cells exposed to 6-OHDA. Furthermore, carvedilol activated the Akt and Nrf2/ARE pathways in a concentration-dependent manner, and increased the protein levels of heme oxygenase-1(HO-1) and NAD(P)H quinone oxidoreductase-1(NQO-1), two downstream factors of the Nrf2/ARE pathway. In summary, our results indicate that carvedilol protects PC12 cells against 6-OHDA-induced neurotoxicity possibly through activating the Akt and Nrf2/ARE signaling pathways.
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Biocompatible sodium alginate fibers by aqueous processing and physical crosslinking.
Carbohydr Polym
PUBLISHED: 02-11-2014
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Sodium alginate (SA) hybrid fibers have been robustly fabricated by electrospinning of aqueous mixtures containing as high as 60% SA in the presence of polyvinyl alcohol (PVA). Solution viscosities of SA, PVA and their mixtures showed fiber spinning to be strongly influenced by the balance between SA-PVA and PVA-PVA intermolecular polar interaction and SA-SA repulsion. Low viscosity SAl (50 mPas at 1%) enabled higher SA loadings without significantly increasing mixture viscosities, producing more cylindrical fibers. All aqueous mixtures containing 33.3-60% SAl (5.68-7.15% total SAl-PVA) had viscosities ranging from 530 to 3600 mPas and could be electrospun continuously for at least 48 h. The SA-PVA hybrid fibers had diameters ranging from ca. 140 to 350 nm and were rendered stable in water via simultaneous ionic-crosslinking SA and crystallization of PVA (5% CaCl2 in 75% EtOH for 30 min). This aqueous electrospinning and physical crosslinking approach is a green and highly efficient alternative to create alginate hybrid fibers that are biologically compatible and ingestible for potential biomedical, food and other applications.
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Acid tolerance response (ATR) of microbial communities during the enhanced biohydrogen process via cascade acid stress.
Bioresour. Technol.
PUBLISHED: 01-18-2014
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Enhanced biohydrogen production via cascade acid stress on microbial communities, structure patterns of the microbial communities revealed by PLFAs, and the succession of biohydrogen related species against cascade acid stress were all investigated. It was found that hydrogen production could be improved from 48.7 to 79.4mL/gVS after cascade acid stress. In addition, the Gram negative (G(-)) bacteria were found to be more tolerant to organic acids than those of the Gram positive (G(+)) bacteria, regardless of the dominance of G(+) bacteria within the microbial communities. Moreover, Clostridium butyricum, Clostridium aciditolerans and Azospira oryzae, were proved to be enriched, and then might play indispensable roles for the enhanced biohydrogen production after cascade acid stress, as which were responsible for the biohydrogen accumulation, acid tolerance and nitrogen removal, respectively.
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Direct glycosylation of bioactive small molecules with glycosyl iodide and strained olefin as acid scavenger.
J. Org. Chem.
PUBLISHED: 01-14-2014
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A new strategy for diversity-oriented direct glycosylation of bioactive small molecules was developed. This reaction features (?)-?-pinene as acid scavenger and work with glycosyl iodides under mild conditions. With the aid of RP-HPLC and chiral SFC separation techniques, the new direct glycosylation proved effective at gram scale on bioactive small molecules including AZD6244, podophyllotoxin, paclitaxel, and docetaxel. Interesting glycoside derivatives were efficiently created with good yields and 1,2-cis selectivity.
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Identification of a new series of potent diphenol HSP90 inhibitors by fragment merging and structure-based optimization.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-08-2014
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Heat shock protein 90 (HSP90) is a molecular chaperone to fold and maintain the proper conformation of many signaling proteins, especially some oncogenic proteins and mutated unstable proteins. Inhibition of HSP90 was recognized as an effective approach to simultaneously suppress several aberrant signaling pathways, and therefore it was considered as a novel target for cancer therapy. Here, by integrating several techniques including the fragment-based drug discovery method, fragment merging, computer aided inhibitor optimization, and structure-based drug design, we were able to identify a series of HSP90 inhibitors. Among them, inhibitors 13, 32, 36 and 40 can inhibit HSP90 with IC50 about 20-40 nM, which is at least 200-fold more potent than initial fragments in the protein binding assay. These new HSP90 inhibitors not only explore interactions with an under-studied subpocket, also offer new chemotypes for the development of novel HSP90 inhibitors as anticancer drugs.
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Fibrinogen Dusart presenting as recurrent thromboses in the hepatic portal system.
Blood Coagul. Fibrinolysis
PUBLISHED: 01-04-2014
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Dysfibrogenemias are characterized by the production of abnormally functioning fibrinogen, occurring in the presence of liver disease, medication toxicity, malignancy, or genetic mutation. Here, we report a patient with multiple, separate episodes of hepatic portal system thromboses associated with dysfibrinogenemia. Molecular studies identified the presence of a 554Arg?Cys mutation in the fibrinogen A? gene, previously identified as Fibrinogen Dusart (also known as Fibrinogen Paris V and Fibrinogen Chapel Hill). This case further illustrates the association of this dysfibrinogenemia with a unique thrombophilic manifestation.
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Role of JNK Activation and Mitochondrial Bax Translocation in Allicin-Induced Apoptosis in Human Ovarian Cancer SKOV3 Cells.
Evid Based Complement Alternat Med
PUBLISHED: 01-02-2014
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Background. Allicin, the major component of freshly crushed garlic, is one of the most biologically active compounds of garlic; it has been reported to induce apoptosis in cancer cells; however, the mechanism by which allicin exerts its apoptotic effects is not fully understood. The aim of the present study was to further elucidate the apoptotic pathways induced by allicin in the human ovarian cancer cell line SKOV3. Methods. Cell proliferation and apoptosis were measured by cell-counting assay and flow cytometry analysis. Activation of the signaling pathway was screened by human phospho-kinase array analysis, and the activated pathway and its related proteins were further confirmed by western blot analysis. Results. Allicin induced SKOV3 cell apoptosis and JNK phosphorylation in a time- and dose-dependent manner, but these were significantly blocked by SP600125 (an inhibitor of JNK). The findings suggest that JNK phosphorylation is related to the action of allicin on SKOV3 cells. Furthermore, JNK activation induced Bcl-2 family activation, triggered mitochondria-mediated signaling pathways, and led to the translocation of a considerable amount of Bax and cytochrome c release. Conclusions. JNK activation and mitochondrial Bax translocation are involved in allicin-induced apoptosis in SKOV3 cells. Our data input new insights to the literature of allicin-induced apoptosis.
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De novo Assembly of the Grass Carp Ctenopharyngodon idella Transcriptome to Identify miRNA Targets Associated with Motile Aeromonad Septicemia.
PLoS ONE
PUBLISHED: 01-01-2014
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De novo transcriptome sequencing is a robust method of predicting miRNA target genes, especially for organisms without reference genomes. Differentially expressed miRNAs had been identified previously in kidney samples collected from susceptible and resistant grass carp (Ctenopharyngodon idella) affected by Aeromonas hydrophila. Target identification for these differentially expressed miRNAs poses a major challenge in this non-model organism.
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Novel mutation in FBN1 causes ectopia lentis and varicose great saphenous vein in one Chinese autosomal dominant family.
Mol. Vis.
PUBLISHED: 01-01-2014
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To identify genetic defects in a Chinese family with ectopia lentis (EL) and varicose great saphenous vein (GSV) and to analyze the correlations between phenotype and genotype.
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Mechanism of temozolomide-induced antitumour effects on glioma cells.
J. Int. Med. Res.
PUBLISHED: 12-10-2013
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To investigate the mechanisms of action of the tumoricidal effects of temozolomide against the human glioma cell line U251 in vitro, and to provide preclinical proof-of-concept studies of the effects of temozolomide-containing regimens.
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[Phenotypic detection and structure analysis of a PC missense mutation (Met406Ile) resulted in venous thromboembolism].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 12-05-2013
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To identify the phenotypic detection and structure analysis of a protein C (PC) missense mutation (Met406Ile) resulting in venous thromboembolism.
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Structure-activity relationship of 39 analogs of laetispicine with antidepressant properties.
Am. J. Chin. Med.
PUBLISHED: 11-16-2013
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The natural product Laetispicine ( N -isobutyl-(3,4-methylendioxyphenyl)-2E, 4E, 9E-undecatrienoamide), was isolated from the Piper laetispicum C. DC and screened, for its antidepressant activity and antinociceptive effects. Structure-functional activities of five natural products indicated that biological activity is dependent on double bonds present within the benzene ring and a conjugated double bond located at positions 2-3 and 4-5 in the molecular structure. To further understand the structural-activity relationship of Laetispicine as a new potent and safe antidepressant, the structural-activity relationship of 39 analogs of Laetispicine were synthetized and tested in forced swimming tests in mice whilst also in protective effects against glutamate or H 2 O 2 induced apoptosis in PC12 cells. The results show that the compound 30 - N -isobutyl-11-(4-chlorophenyl) undeca-2E,4E,9E-trienamide exhibited the same activity as the parental compound Laetispicine, and furthermore, the effective dose of this compound is lower than Laetispicine. Therefore, the compound 30 might be a potentially useful therapy in the treatment of depression. For structure, the conjugated double bonds located at 2-3, 4-5 and isolated double bonds from benzene ring are necessary for the antidepressant activities no matter the different length of carbon chain; the isobutyl connected with acylamino also are necessary; and the benzodioxole moiety is replaceable, the halogen atom in phenyl ring at the para-position could enhance this kind of activity.
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Paper-based device for rapid typing of secondary human blood groups.
Anal Bioanal Chem
PUBLISHED: 09-26-2013
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We report the use of bioactive paper for typing of secondary human blood groups. Our recent work on using bioactive paper for human blood typing has led to the discovery of a new method for identifying haemagglutination of red blood cells. The primary human blood groups, i.e., ABO and RhD groups, have been successfully typed with this method. Clinically, however, many secondary blood groups can also cause fatal blood transfusion accidents, despite the fact that the haemagglutination reactions of secondary blood groups are generally weaker than those of the primary blood groups. We describe the design of a user-friendly sensor for rapid typing of secondary blood groups using bioactive paper. We also present mechanistic insights into interactions between secondary blood group antibodies and red blood cells obtained using confocal microscopy. Haemagglutination patterns under different conditions are revealed for optimization of the assay conditions.
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A highly sensitive and selective homogenous assay for profiling microRNA expression.
Biosens Bioelectron
PUBLISHED: 09-20-2013
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A highly sensitive and selective homogeneous microRNA (miRNA) assay is described in this report. It is based on the cleavage of DNAzyme moieties from miRNA-hybridized DNAzyme-capped capture probes (DZ-CPs) from magnetic beads by a duplex-specific nuclease (DSN). After removing the magnetic beads together with the unreacted DZ-CPs by using a permanent magnet, amplified colorimetric detection of the target miRNA is realized through the cleaved DNAzyme moieties-catalyzed oxidation of 3,3,5,5-tetramethylbenzidine. The exceptional amplification power of the DSN and the cumulative nature of the signal generation process permit the colorimetric detection of miRNAs down to subfemtomolar levels. The isothermal amplification scheme together with the simple assay protocol makes direct profiling miRNA in real-world samples possible.
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Exemplar-Based Human Action Pose Correction.
IEEE Trans Cybern
PUBLISHED: 09-18-2013
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The launch of Xbox Kinect has built a very successful computer vision product and made a big impact on the gaming industry. This sheds lights onto a wide variety of potential applications related to action recognition. The accurate estimation of human poses from the depth image is universally a critical step. However, existing pose estimation systems exhibit failures when facing severe occlusion. In this paper, we propose an exemplar-based method to learn to correct the initially estimated poses. We learn an inhomogeneous systematic bias by leveraging the exemplar information within a specific human action domain. Furthermore, as an extension, we learn a conditional model by incorporation of pose tags to further increase the accuracy of pose correction. In the experiments, significant improvements on both joint-based skeleton correction and tag prediction are observed over the contemporary approaches, including what is delivered by the current Kinect system. Our experiments for the facial landmark correction also illustrate that our algorithm can improve the accuracy of other detection/estimation systems.
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Functional analysis of serially expanded human iPS cell-derived RPE cultures.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 09-14-2013
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To determine the effects of serial expansion on the cellular, molecular, and functional properties of human iPS cell (hiPSC)-derived RPE cultures.
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An ultrasensitive homogeneous chemiluminescent assay for microRNAs.
Chem. Commun. (Camb.)
PUBLISHED: 09-11-2013
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On the basis of a dual-amplification strategy, microRNA (miRNA) hybridization amplification by a duplex-specific nuclease (DSN) and signal amplification by a DNAzyme, a highly sensitive and selective homogeneous miRNA assay is developed. By leveraging on the cumulative and selective nature of the DSN amplification process, excellent sensitivity and selectivity are accomplished.
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Synthesis and biological evaluation of 6H-pyrido[2,1:2,3]imidazo[4,5-c]isoquinolin-5(6H)-ones as antimitotic agents and inhibitors of tubulin polymerization.
Bioorg. Med. Chem.
PUBLISHED: 08-19-2013
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A series of 6H-pyrido[2,1:2,3]imidazo[4,5-c]isoquinolin-5(6H)-ones have been synthesized and evaluated for their antiproliferative activities. Among them, compounds 2j and 4d displayed potent cytotoxic activities in vitro against HeLa cell line with IC50 values of 0.07 and 0.06?M, respectively. In general, the antiproliferative activities are correlated with the inhibitory effect on tubulin polymerization and binding property of the colchicine binding site. In addition, flow cytometry and immunofluorescence analysis revealed selected compounds caused G2/M phase arrest of the cell cycle and disruption of the mitotic spindle assembly, which had correlation with proliferation inhibitory activity.
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Engineered fungal polyketide biosynthesis in Pichia pastoris: a potential excellent host for polyketide production.
Microb. Cell Fact.
PUBLISHED: 07-28-2013
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Polyketides are one of the most important classes of secondary metabolites and usually make good drugs. Currently, heterologous production of fungal polyketides for developing a high potential industrial application system with high production capacity and pharmaceutical feasibility was still at its infancy. Pichia pastoris is a highly successful system for the high production of a variety of heterologous proteins. In this work, we aim to develop a P. pastoris based in vivo fungal polyketide production system for first time and evaluate its feasibility for future industrial application.
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[Factors related to the poor coronary collateral circulation in patients with coronary artery disease].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 07-15-2013
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To explore the factors related to poor coronary collateral circulation (CCC) and the synergy effects among various factors in patients with coronary artery disease (CAD).
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Role of ADAMTS13 in the management of thrombotic microangiopathies including thrombotic thrombocytopenic purpura (TTP).
Br. J. Haematol.
PUBLISHED: 06-04-2013
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The clinical presentation of thrombotic thrombocytopenia purpura (TTP) and other thrombotic microangiopathies (TMAs) can often be similar. The role of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) in diagnosing TTP is accepted by most researchers but continues to be debated in a few studies. We report the experience of our single-centre academic institution, where ADAMTS13 is used to diagnose TTP and guide plasma exchange (PLEX). Patients presenting to our institution with thrombotic microangiopathy (60 patients) between January 2006 and December 2012 were divided into two groups based on ADAMTS13 activity and clinical history. Patients with ADAMTS13 activity <10% were included in the TTP (n = 30) cohort while patients with activity >11% were classified as other microangiopathies (TMA, n = 30). PLEX was only initiated in patients with a high likelihood of TTP and discontinued when the baseline ADAMTS13 activity was >11%. Patients with severe ADAMTS13 deficiency (TTP group) showed significant presenting differences: lower platelet counts, less renal dysfunction, higher presence of neurological abnormalities, and greater haemolysis markers as compared to non-deficient patients (TMA group). Most importantly, patients without severe ADAMTS13 deficiency were safely managed without increased mortality despite receiving no PLEX or discontinuing PLEX after a short course (upon availability of ADAMTS13 results). In conclusion, ADAMTS13 can be used to diagnose TTP and guide appropriate PLEX therapy.
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Fragment-based drug discovery of 2-thiazolidinones as inhibitors of the histone reader BRD4 bromodomain.
J. Med. Chem.
PUBLISHED: 05-14-2013
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Recognizing acetyllysine of histone is a vital process of epigenetic regulation that is mediated by a protein module called bromodomain. To contribute novel scaffolds for developing into bromodomain inhibitors, we utilize a fragment-based drug discovery approach. By successively applying docking and X-ray crystallography, we were able to identify 9 fragment hits from diffracting more than 60 crystals. In the present work, we described four of them and carried out the integrated lead optimization for fragment 8, which bears a 2-thiazolidinone core. After several rounds of structure guided modifications, we assessed the druggability of 2-thiazolidinone by modulating in vitro pharmacokinetic studies and cellular activity assay. The results showed that two potent compounds of 2-thiazolidinones have good metabolic stability. Also, the cellular assay confirmed the activities of 2-thiazolidinones. Together, we hope the identified 2-thiazolidinone chemotype and other fragment hits described herein can stimulate researchers to develop more diversified bromodomain inhibitors.
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Novel nonsecosteroidal VDR agonists with phenyl-pyrrolyl pentane skeleton.
Eur J Med Chem
PUBLISHED: 05-11-2013
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In order to find the vitamin D receptor (VDR) ligand whose VDR agonistic activity is separated from the calcemic activity sufficiently, novel nonsecosteroidal analogs with phenyl-pyrrolyl pentane skeleton were synthesized and evaluated for the VDR binding affinity, antiproliferative activity in vitro and serum calcium raising ability in vivo (tacalcitol used as control). Among them, several compounds showed varying degrees of VDR agonistic and growth inhibition activities of the tested cell lines. The most effective compound 2g (EC??: 1.06 nM) exhibited stronger VDR agonistic activity than tacalcitol (EC??: 7.05 nM), inhibited the proliferations of HaCaT and MCF-7 cells with IC?? of 2.06 ?M and 0.307 ?M (tacalcitol: 2.07 ?M and 0.057 ?M) and showed no significant effect on serum calcium.
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Use of health-related quality of life measures to predict health utility in postmenopausal osteoporotic women: results from the Multiple Outcomes of Raloxifene Evaluation study.
Health Qual Life Outcomes
PUBLISHED: 05-08-2013
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The aim of this study is to examine the associations between health utility (HU), health-related quality of life (HRQoL), and patient characteristics in postmenopausal osteoporotic (PMO) women.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

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.