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Find video protocols related to scientific articles indexed in Pubmed.
Inhibition of tumor growth by ?-elemene through downregulation of the expression of uPA, uPAR, MMP-2, and MMP-9 in a murine intraocular melanoma model.
Melanoma Res.
PUBLISHED: 11-19-2014
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This paper explores the underlying mechanism through which ?-elemene inhibits the growth of intraocular melanoma in a mouse model. C57BL/6J mice were administered a subretinal injection of B16F10 melanoma cells and divided into two groups: treatment and control. The treatment group was administered ?-elemene through an intravitreal injection and the control group was injected with a blank emulsion. After 21 days of continuous treatment, tumor masses were removed and weighed. The mRNA expression levels of the urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), matrix metalloproteinase (MMP)-2, and MMP-9 were assayed by real-time PCR, and the protein expression levels of uPA, uPAR, MMP-2, and MMP-9 were assayed by immunocytochemistry and western blotting. Tumor size was inhibited by ?-elemene in the treatment group, and the expressions of uPA, uPAR, MMP-2, and MMP-9 were all downregulated at both the mRNA and the protein level compared with the control group. In a mouse model of intraocular melanoma, ?-elemene inhibits tumor growth by downregulating the expression of uPA, uPAR, MMP-2, and MMP-9.
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Fabrication of long-focal-length plano-convex microlens array by combining the micro-milling and injection molding processes.
Appl Opt
PUBLISHED: 11-18-2014
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A uniform plano-convex spherical microlens array with a long focal length was fabricated by combining the micromilling and injection molding processes in this work. This paper presents a quantitative study of the injection molding process parameters on the uniformity of the height of the microlenses. The variation of the injection process parameters, i.e., barrel temperature, mold temperature, injection speed, and packing pressure, was found to have a significant effect on the uniformity of the height of the microlenses, especially the barrel temperature. The filling-to-packing switchover point is also critical to the uniformity of the height of the microlenses. The optimal uniformity was achieved when the polymer melts completely filled the mold cavity, or even a little excessively filled the cavity, during the filling stage. In addition, due to the filling resistance, the practical filling-to-packing switchover point can vary with the change of the filling processing conditions and lead to a non-negligible effect on the uniformity of the height of the microlenses. Furthermore, the effect of injection speed on the uniformity of the height of the microlenses was analyzed in detail. The results indicated that the effect of injection speed on the uniformity of the height of the microlenses is mainly attributed to the two functions of injection speed: transferring the filling-to-packing switchover point and affecting the distribution of residual flow stress in the polymer melt.
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Simultaneous strain and temperature measurement by cascading few-mode fiber and single-mode fiber long-period fiber gratings.
Appl Opt
PUBLISHED: 11-18-2014
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A hybrid optical fiber structure of two cascading long-period fiber gratings (LPFGs), respectively, inscribed on a segment of few-mode fiber (FMF) and single-mode fiber (SMF), is proposed and experimentally demonstrated. This structure could be used for simultaneous measurement of strain and temperature. The FMF-LPFG exhibits an opposite temperature response and higher strain sensitivity compared to that of the SMF-LPFG, which can improve the measurement resolutions. Experimentally, the strain and temperature sensitivities of the proposed sensor are -2.9??pm/?? and -17.6??pm/°C, respectively, for the FMF-LPFG; for the SMF-LPFG, these are -1.47??pm/?? and 46.4??pm/°C, respectively. The maximum errors are ±7.98???? and ±0.54°C for strain and temperature, respectively.
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Thermally tunable electric mie resonance of dielectric cut-wire type metamaterial.
Opt Express
PUBLISHED: 11-18-2014
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In this manuscript, we present on a thermally tunable electric Mie resonance of dielectric cut-wire type metamaterial. Dielectric cut-wire exhibits Lorentz-type frequency dependent negative effective permittivity followed by zero value around its fundamental Mie resonance, resulting from dipole-oscillation of displacement currents. Furthermore, the operation frequency of electric resonance frequency can be varied by wire length and temperature variation. As environmental temperature changes by 40 °C, electric Mie resonance can be reversibly tuned by 1000 MHz, due to the thermal dependent permittivity character of ceramic.
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MicroRNA-200 Cluster Regulation by Ascl2: Impact on the Epithelial-mesenchymal Transition in Colon Cancer Cells.
J. Biol. Chem.
PUBLISHED: 11-06-2014
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Achaete scute-like 2 (Ascl2), a basic helix-loop-helix (bHLH) transcription factor, is a downstream target of Wnt signaling that controls the fate of intestinal cryptic stem cells and colon cancer progenitor cells. However, its involvement in colon cancer and downstream molecular events is largely undefined; in particular, the mechanism by which Ascl2 regulates the plasticity of epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) programs in colon cancer cells remains unknown. In this study, we systematically demonstrate that Ascl2 loss-of-function in colon cancer cells promotes MET by de-repressing the expression of miR-200s (i.e., miR-200b, miR-200a, miR-429, miR-200c and miR-141) and further activating their expression through a transcriptional mechanism that involves direct binding to the most proximal E-box (E-box2) in the miR-200b-a-429 promoter. Activation of miR-200s due to Ascl2 deficiency led to the inhibition of Zeb1/2 expression and the alteration of epithelial and mesenchymal features. Transfection of miR-200b, miR-200a and miR-429 inhibitors into Ascl2-deficient colon cancer cells promoted the epithelial-mesenchymal transition in a reversible manner. Transfection of miR-200a or miR-429 inhibitors into Ascl2-deficient colon cancer cells increased cellular proliferation and migration. Ascl2 mRNA levels and miRNA-200a, miRNA-200b, miRNA-200c, miRNA-141 or miRNA-429 levels in the colon cancerous samples were inversely correlated. These results provide the first evidence of a link between Ascl2 and miR-200s in the regulation of EMT-MET plasticity in colon cancer.
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Whole Genome Sequence of the Treponema pallidum subsp. endemicum Strain Bosnia A: The Genome Is Related to Yaws Treponemes but Contains Few Loci Similar to Syphilis Treponemes.
PLoS Negl Trop Dis
PUBLISHED: 11-01-2014
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T. pallidum subsp. endemicum (TEN) is the causative agent of bejel (also known as endemic syphilis). Clinical symptoms of syphilis and bejel are overlapping and the epidemiological context is important for correct diagnosis of both diseases. In contrast to syphilis, caused by T. pallidum subsp. pallidum (TPA), TEN infections are usually spread by direct contact or contaminated utensils rather than by sexual contact. Bejel is most often seen in western Africa and in the Middle East. The strain Bosnia A was isolated in 1950 in Bosnia, southern Europe.
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One-year and long-term molecular response to nilotinib and dasatinib for newly diagnosed chronic myeloid leukemia: a matching-adjusted indirect comparison.
Curr Med Res Opin
PUBLISHED: 10-31-2014
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Abstract Background: Nilotinib and dasatinib have shown superior rates of molecular response (MR) compared to imatinib for the treatment of newly diagnosed chronic myeloid leukemia (CML) in chronic phase (CP). This study indirectly compares MR in patients taking nilotinib 300?mg bid with that in those taking dasatinib 100?mg qd by 12 months and through 48 months. Methods: Patients in ENESTnd were re-weighted to match published baseline characteristics reported for DASISION using a propensity score model. After matching, differences in rates of major MR (MMR, measured as a 3?log reduction on the International Scale [IS]), MR(4.0) (4?log reduction on IS), and MR(4.5) (4.5?log reduction on IS) relative to imatinib were indirectly compared between nilotinib and dasatinib. Hazard ratios (HRs) were used to indirectly compare MR outcomes between nilotinib and dasatinib through 48 months of follow-up, while rate differences were used to compare progression to AP/BC between nilotinib and dasatinib by 48 months. Results: After matching, rates of MR by 12 months were higher with nilotinib vs dasatinib by 11.7% for MMR (p?=?0.045), 8.2% for MR(4.0) (p?=?0.029), and 8.5% for MR(4.5) (p?
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Convex Nanobending at a Moving Contact Line: The Missing Mesoscopic Link in Dynamic Wetting.
ACS Nano
PUBLISHED: 10-23-2014
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The morphological information on the very front of a spreading liquid is fundamental to our understanding of dynamic wetting. Debate has lasted for years concerning the nanoscopic local angles and the transition from them to the macroscopic counterpart, ?D. This study of nonvolatile liquids analyzes the interface profile near the advancing contact line using an advanced atomic force microscopy. The interface is found following the macroscopic profile until bending in a convex profile around 20 nm from the substrate. This shoe-tip-like feature is common in partially wetting while absent for completely wetting, and its curvature varies with advancing speed. The observation ends the long-standing debate about the nanoscopic contact angles and their speed dependency. The convex nanobending provides a mesoscopic link and effectively complicates the dynamic wetting behaviors.
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Levetiracetam Effect on Adult-Onset Temporal Lobe Epilepsy With Positive Voltage-Gated Potassium Channel Antibody.
J Neuropsychiatry Clin Neurosci
PUBLISHED: 10-17-2014
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Temporal lobe epilepsy is considered to be the most frequent of all epileptic syndromes. Recently, several retrospective studies suggest that limbic encephalitis (LE) may be a cause for adult onset unexplained seizure disorders in patients. This report describes two cases of adult onset epilepsy with voltage-gated potassium channel antibodies (VGKC-abs)-associated LE that responded well to levetiracetam (LEV). As demonstrated by these two cases and reviewing previous reports, we propose that the therapeutic regimen for VGKC-abs associated seizures still needs to be determined and LEV may be effective in treating this kind of disorders.
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Antimicrobial Resistance Investigation on Staphylococcus Strains in a Local Hospital in Guangzhou, China, 2001-2010.
Microb. Drug Resist.
PUBLISHED: 10-10-2014
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A retrospective study was conducted on 1,739 Staphylococcus isolates from the First Affiliated Hospital of Jinan University (FAHJU) in Guangzhou during 2001-2010. With the exception of teicoplanin and vancomycin, antimicrobial resistance was commonly observed among the isolates examined, with high resistance rates for ?-lactamases (94.0% and 73.7% for penicillin and oxacillin) and resistance percentages for cefoxitin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, gentamicin, trimethoprim-sulfamethoxazole, and tetracycline ranging from 83.9% to 19.4%. Two hundred sixty-three of the 1,739 isolates were subjected to SCCmec typing and 42 to MLST, spaA, and coa typing. ST239-MRSA-III was prevalently identified along with one distinct coa type HIJKL and 2 spaA types (WGKAOMQ-t037 and WGKAQQ-t030). Class 1 integrons were commonly detected (31.6%), although none of the integron-positive MRSA strains had been isolated since 2009. The widespread detection of integron-based antimicrobial resistance determinants may further contribute to the emergence of superbugs.
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[Anti-depressant effect and mechanism of supercritical CO2 extract from Compound Chaigui Fang].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 10-03-2014
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The tail suspension test (TST), forced swimming test (FST) and chronic unpredictable mild stress (CUMS) model were used to evaluate the anti-depressant effect of supercritical CO2 extract from Compound Chaigui Fang (FFCGF). A nuclear magnetic resonance (NMR)-based metabonomics combined with multivariate statistical analysis was performed to explore the mechanism of FFCGF. Rats were conducted by CUMS procedure for 28 days and drugs were administrated at the same time. The body weight, sucrose preference, crossings and rearings in open-field tests were evaluated and the urine was collected simultaneously. The metabonomic profiles of rats' urine were analyzed by NMR and potential biomarkers were searched by multivariate statistical analysis. The results showed that administration of FFCGF significantly decreasing the immobility time in FST and TST and improving rats' body weight, sucrose preference, crossings and rearings in CUMS, which were indication that the anti-depressant effect of FFCGF was abvious. Significant differences in the metabolic profile of the CUMS treated group and the control group were observed, which were consistent with the results of behavioral tests. Decreased levels of acetic acid, succinic acid, 2-oxidation glutaric acid and citric acid and increased glycine and pyruvic acid in urine were significantly affected by the CUMS procedure and the 6 biomarkers were reversed evidently after administration of FFCGF. These changes were suggestion that the anti-depressant mechanism of FFCGF was associated with energy metabolism, lipid metabolism and amino acid metabolism.
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[Comparison of the occlusion effect of three kinds of desensitizers on dentinal tubules].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 10-02-2014
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To explore the effects of three dentine desensitizers on the surface morphology of freshly exposed dentin and to evaluate their occlusion effects on dentinal tubules using scanning electron microscope (SEM).
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Phenotypic and Genotypic Analysis of Clostridium difficile Isolates: a Single-Center Study.
J. Clin. Microbiol.
PUBLISHED: 10-01-2014
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Clostridium difficile infections (CDI) are a growing concern in North America, because of their increasing incidence and severity. Using integrated approaches, we correlated pathogen genotypes and host clinical characteristics for 46 C. difficile infections in a tertiary care medical center during a 6-month interval from January to June 2010. Multilocus sequence typing (MLST) demonstrated 21 known and 2 novel sequence types (STs), suggesting that the institution's C. difficile strains are genetically diverse. ST-1 (which corresponds to pulsed-field gel electrophoresis strain type NAP1/ribotype 027) was the most prevalent (32.6%); 43.5% of the isolates were binary toxin gene positive, of which 75% were ST-1. All strains were ciprofloxacin resistant and metronidazole susceptible, and 8.3% and 13.0% of the isolates were resistant to clindamycin and tetracycline, respectively. The corresponding resistance loci, including potential novel mutations, were identified from the whole-genome sequencing (WGS) of the resistant strains. Core genome single nucleotide polymorphisms (SNPs) determining the phylogenetic relatedness of the 46 strains recapitulated MLST types and provided greater interstrain differentiation. The disease severity was greatest in patients infected with ST-1 and/or binary gene-positive strains, but genome-wide SNP analysis failed to provide additional associations with CDI severity within the same STs. We conclude that MLST and core genome SNP typing result in the same phylogenetic grouping of the 46 C. difficile strains collected in a single hospital. WGS also has the capacity to differentiate those strains within STs and allows the comparison of strains at the individual gene level and at the whole-genome level.
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[Lentiviral vector-mediated RNA interference of mouse epididymis-specific meClps gene lowers mouse sperm mobility].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 09-30-2014
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To analyze the effect of small interfering RNA (siRNA) targeting mouse epididymis-specific colipase-like (meClps) gene on mouse sperm mobility.
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[Case-control study on treatment of distal tibiofibula fractures with modified anterolateral or traditional approach].
Zhongguo Gu Shang
PUBLISHED: 09-23-2014
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To explore therapeutic effects of modified anterolateral approach and traditional approach in treating distal tibiofibula fractures.
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A transcriptional regulator Sll0794 regulates tolerance to biofuel ethanol in photosynthetic Synechocystis sp. PCC 6803.
Mol. Cell Proteomics
PUBLISHED: 09-21-2014
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To improve ethanol production directly from CO2 in photosynthetic cyanobacterial systems, one key issue that needs to be addressed is the low ethanol tolerance of cyanobacterial cells. Our previous proteomic and transcriptomic analyses found that several regulatory proteins were up regulated by exogenous ethanol in Synechocystis sp. PCC6803. In this study, through tolerance analysis of the gene disruption mutants of the up-regulated regulatory genes, we uncovered that one transcriptional regulator, Sll0794, was related directly to ethanol tolerance in Synechocystis. Using a quantitative iTRAQ-LC-MS/MS proteomics approach coupled with quantitative real-time reverse transcription-PCR (RT-qPCR), we further determined the possible regulatory network of Sll0794. The proteomic analysis showed that in the ?sll0794 mutant grown under ethanol stress a total of 54 and 87 unique proteins were down- and up-regulated, respectively. In addition, electrophoretic mobility shift assays (EMSAs) demonstrated that the Sll0794 transcriptional regulator was able to bind directly to the upstream regions of sll1514, slr1512 and slr1838, which encode a 16.6 kDa small heat shock protein, a putative sodium-dependent bicarbonate transporter and a carbon dioxide concentrating mechanism protein CcmK, respectively. The study provided a proteomic description of the putative ethanol-tolerance network regulated by the sll0794 gene, and revealed new insights on the ethanol-tolerance regulatory mechanism in Synechocystis. As the first regulatory protein discovered related to ethanol tolerance, the gene may serve as a valuable target for transcription machinery engineering to further improve ethanol tolerance in Synechocystis. All MS data have been deposited in the ProteomeXchange with identifier PXD001266 (http://proteomecentral.proteomexchange.org/dataset/ PXD001266).
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Structure activity relationships of flavonoids as potent alpha-amylase inhibitors.
Nat Prod Commun
PUBLISHED: 09-20-2014
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The effects of three flavonoids (quercetin, luteolin, diosmetin) on alpha-amylase were examined by enzymatic kinetics and fluorescence spectroscopy. The three test flavonoids were non-competitive inhibitors of the enzyme. Addition of flavonoids led to fluorescence quenching of alpha-amylase. The quenching was initiated from the formation of a complex between the flavonoids and the enzyme, corresponding to a static quenching process. An alpha-amylase molecule provides a binding site for the test flavonoid. The main binding force was hydrophobic. The decreasing order of inhibition of alpha-amylase by flavonoids and the binding force was luteolin, diosmetin, and quercetin. It is demonstrated that hydroxylation in ring C and methylation of the hydroxyl group in ring B of flavonoids may weaken the binding affinities to alpha-amylase.
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Synergistic increase of oxidative stress and tumor markers in PAH-exposed workers.
Asian Pac. J. Cancer Prev.
PUBLISHED: 09-18-2014
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In this study, we investigated oxidative stress and tumor marker levels of polycyclic aromatic hydrocarbons (PAHs) in 136 coke oven workers and in 60 control subjects, and evaluated the correlation between oxidative stress and tumor marker levels. Questionnaires on basic demographic information were also administered. Significant differences in employment time and percentages of alcohol drinkers were observed between the control and exposed groups. PAH exposure was assessed using urinary 1-hydroxy-pyrene (1-OHP) levels and was found to be significantly higher in workers than in the controls. Significant differences (P<0.001) of MDA, GST, LDH, NSE, Cyfra21-1, and of SCC and TNF-a (P<0.0001 and P<0.05, P<0.001, respectively) levels were observed among controls and coke-oven workers, except for bottom coke oven workers. Associations between age and risk of increased TNF-a, smoking and increased GST activities, and drinking with increased MDA concentrations, were marginal (P=0.055, P=0.048, P=0.057, respectively). The association between smoking with MDA (P=0.004), NSE (P=0.005), SCC (P=0.004) and TNF-a (P<0.001), and drinking with TNF-a levels was significant (P=0.012). In addition, a significant positive correlation between oxidative stress and tumor markers was found in the present study. These results suggest that a synergistic increase of oxidative stress and tumor markers induced by PAHs may play a role in toxic responses for PAHs in coke oven workers.
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Antioxidant and antiangiogenic properties of phenolic extract from Pleurotus tuber-regium.
J. Agric. Food Chem.
PUBLISHED: 09-18-2014
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Pleurotus tuber-regium (Fries) Singer (PTR), both an edible and a medicinal mushroom also known as tiger milk mushroom, has experienced growing popularity and economic importance due to its flavor, nutritive value, and medicinal effects. In this study, the antioxidant and antiangiogenic activities of a 60% ethanol extract (EE) obtained from the sclerotium of PTR were investigated. Typical phenolic compounds including protocatechuic, chlorogenic, syringic, ferulic, and folic acid were identified and quantified in EE by the HPLC-UV-ESI/MS analyses. EE possessed strong antioxidant activity and could dose-dependently inhibit vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cells (HUVEC) migration and tube formation. qPCR results showed that VEGF-induced FGF, ANG-Tie, and MMP gene expression as well as VEGFR were down-regulated at the mRNA level after treated with EE, suggesting that multiple molecular targets related to angiogenesis was involved. Furthermore, EE also inhibited the formation of subintestinal vessel plexus (SIVs) in zebrafish embryos in vivo. All of these suggested that EE of PTR could be the source of potential inhibitors to target angiogenesis.
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Structure and mechanism of the unique C2 domain of Aida.
FEBS J.
PUBLISHED: 09-06-2014
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Axin interactor, dorsalization-associated (Aida) was identified as a regulatory factor that utilizes its C-terminal region to interact with axis formation inhibitor (Axin). Aida abrogates the Axin-mediated Jun N-terminal kinase activation required for proper dorsalization during zebrafish embryonic development, and thus functions as a proventralization factor. Here, we report the structure of Aida C-terminal fragments, which adopt a conventional C2 domain topology. We also demonstrate that Aida can specifically bind to phosphoinositides in a Ca(2+) -independent manner, and is able to associate with the cell membrane via a novel positively charged surface, namely a basic loop. Mutation of the positively charged patch on the basic loop leads to destabilization of the Aida-membrane association or disruption of the Aida-Axin interaction, resulting in impaired Jun N-terminal kinase inhibition. Together, our findings provide a molecular basis for C2 domain-mediated Aida-membrane and Aida-Axin associations.
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Metabolomic basis of laboratory evolution of butanol tolerance in photosynthetic Synechocystis sp. PCC 6803.
Microb. Cell Fact.
PUBLISHED: 09-04-2014
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BackgroundRecent efforts demonstrated the potential application of cyanobacteria as a ¿microbial cell factory¿ to produce butanol directly from CO2. However, cyanobacteria have very low tolerance to the toxic butanol, which limits the economic viability of this renewable system.ResultsThrough a long-term experimental evolution process, we achieved a 150% increase of the butanol tolerance in a model cyanobacterium Synechocystis sp. PCC 6803 after a continuous 94 passages for 395 days in BG11 media amended with gradually increased butanol concentration from 0.2% to 0.5% (v/v). To decipher the molecular mechanism responsible for the tolerance increase, we employed an integrated GC-MS and LC-MS approach to determine metabolomic profiles of the butanol-tolerant Synechocystis strains isolated from several stages of the evolution, and then applied PCA and WGCNA network analyses to identify the key metabolites and metabolic modules related to the increased tolerance. The results showed that unstable metabolites of 3-phosphoglyceric acid (3PG), D-fructose 6-phosphate (F6P), D-glucose 6-phosphate (G6P), NADPH, phosphoenolpyruvic acid (PEP), D-ribose 5-phosphate (R5P), and stable metabolites of glycerol, L-serine and stearic acid were differentially regulated during the evolution process, which could be related to tolerance increase to butanol in Synechocystis.ConclusionsThe study provided the first time-series description of the metabolomic changes related to the gradual increase of butanol tolerance, and revealed a metabolomic basis important for rational tolerance engineering in Synechocystis.
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A micro oxygen sensor based on a nano sol-gel TiO2 thin film.
Sensors (Basel)
PUBLISHED: 09-03-2014
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An oxygen gas microsensor based on nanostructured sol-gel TiO2 thin films with a buried Pd layer was developed on a silicon substrate. The nanostructured titania thin films for O2 sensors were prepared by the sol-gel process and became anatase after heat treatment. A sandwich TiO2 square board with an area of 350 ?m × 350 ?m was defined by both wet etching and dry etching processes and the wet one was applied in the final process due to its advantages of easy control for the final structure. A pair of 150 nm Pt micro interdigitated electrodes with 50 nm Ti buffer layer was fabricated on the board by a lift-off process. The sensor chip was tested in a furnace with changing the O2 concentration from 1.0% to 20% by monitoring its electrical resistance. Results showed that after several testing cycles the sensor's output becomes stable, and its sensitivity is 0.054 with deviation 2.65 × 10(-4) and hysteresis is 8.5%. Due to its simple fabrication process, the sensor has potential for application in environmental monitoring, where lower power consumption and small size are required.
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Selective ligands of estrogen receptor ? discovered using pharmacophore mapping and structure-based virtual screening.
Acta Pharmacol. Sin.
PUBLISHED: 09-01-2014
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To discover novel ligands of estrogen receptor (ER) ? using pharmacophore mapping and structure-based screening.
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EGFR has a tumour-promoting role in liver macrophages during hepatocellular carcinoma formation.
Nat. Cell Biol.
PUBLISHED: 08-31-2014
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Hepatocellular carcinoma (HCC) is a frequent cancer with limited treatment options and poor prognosis. Tumorigenesis has been linked with macrophage-mediated chronic inflammation and diverse signalling pathways, including the epidermal growth factor receptor (EGFR) pathway. The precise role of EGFR in HCC is unknown, and EGFR inhibitors have shown disappointing clinical results. Here we discover that EGFR is expressed in liver macrophages in both human HCC and in a mouse HCC model. Mice lacking EGFR in macrophages show impaired hepatocarcinogenesis, whereas mice lacking EGFR in hepatocytes unexpectedly develop more HCC owing to increased hepatocyte damage and compensatory proliferation. Mechanistically, following interleukin-1 stimulation, EGFR is required in liver macrophages to transcriptionally induce interleukin-6, which triggers hepatocyte proliferation and HCC. Importantly, the presence of EGFR-positive liver macrophages in HCC patients is associated with poor survival. This study demonstrates a tumour-promoting mechanism for EGFR in non-tumour cells, which could lead to more effective precision medicine strategies.
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Efficacy and safety of bevacizumab in Chinese patients with metastatic colorectal cancer.
Asian Pac. J. Cancer Prev.
PUBLISHED: 08-30-2014
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To evaluate the efficacy and safety of bevacizumab in the treatment of patients with metastatic colorectal cancer (mCRC).
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Discrepancy between subjectively reported symptoms and objectively measured clinical findings in dry eye: a population based analysis.
BMJ Open
PUBLISHED: 08-28-2014
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To investigate the discrepancy between patient-reported symptoms and measured clinical findings and influencing factors in dry eye (DE).
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Compounding local invariant features and global deformable geometry for medical image registration.
PLoS ONE
PUBLISHED: 08-28-2014
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Using deformable models to register medical images can result in problems of initialization of deformable models and robustness and accuracy of matching of inter-subject anatomical variability. To tackle these problems, a novel model is proposed in this paper by compounding local invariant features and global deformable geometry. This model has four steps. First, a set of highly-repeatable and highly-robust local invariant features, called Key Features Model (KFM), are extracted by an effective matching strategy. Second, local features can be matched more accurately through the KFM for the purpose of initializing a global deformable model. Third, the positional relationship between the KFM and the global deformable model can be used to precisely pinpoint all landmarks after initialization. And fourth, the final pose of the global deformable model is determined by an iterative process with a lower time cost. Through the practical experiments, the paper finds three important conclusions. First, it proves that the KFM can detect the matching feature points well. Second, the precision of landmark locations adjusted by the modeled relationship between KFM and global deformable model is greatly improved. Third, regarding the fitting accuracy and efficiency, by observation from the practical experiments, it is found that the proposed method can improve 6~8% of the fitting accuracy and reduce around 50% of the computational time compared with state-of-the-art methods.
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The mechanism of N-Ag bonding determined tunability of surface-enhanced Raman scattering of pyridine on MAg (M = Cu, Ag, Au) diatomic clusters.
Phys Chem Chem Phys
PUBLISHED: 08-26-2014
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Binary coinage metal clusters can show a significantly different enhancement in surface-enhanced Raman scattering (SERS) from that of pure element clusters, owing to their tunable surface plasmon resonance energies affected by the composition and atomic ordering. Yet, the tunability by composition requires a deep understanding in order to further optimize the SERS-based detection technique. Here, to fill this deficiency, we conducted detailed analyses of the SERS of pyridine adsorbed through N-Ag bonding on the homonuclear diatomic metal cluster Ag2 and heteronuclear diatomic metal clusters of AuAg and CuAg, as well as the involved charge transfer under an intracluster excitation, based on calculations using time-dependent density functional theory with a short-time approximation for the Raman cross-section. We find that although the SERS enhancements for all complexes can reach the order of 10(3)-10(4), the corresponding wavelengths used for SERS excitation are significantly different. Our molecular orbital analysis reveals that the complexes based on heteronuclear metal clusters can produce varied electronic transitions owing to the polarization between different metal atoms, which tune the SERS enhancements with altered optical properties. Our analyses are expected to provide a theoretical basis for exploring the multi-composition SERS substrates applicable for single molecular detection, nanostructure characterization, and biological molecular identification.
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An in silico protocol for identifying mTOR inhibitors from natural products.
Mol. Divers.
PUBLISHED: 08-26-2014
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The mammalian target of rapamycin (mTOR) is an anti-cancer target. In this study, we propose an in silico protocol for identifying mTOR inhibitors from the ZINC natural product database. First, a three-dimensional quantitative structure-activity relationship pharmacophore model was built based on known mTOR inhibitors. The model was validated with an external test set, Fischer's randomization method, a decoy set and pharmacophore mapping conformation testing. The results showed that the model can predict the mTOR inhibition activity of the tested compounds. Virtual screening was performed based on the best pharmacophore model, and the results were then filtered using a molecular docking approach. In addition, molecular mechanics/generalized born surface area analysis was used to refine the selected candidates. The top 20 natural products were selected as potential mTOR inhibitors, and their structural scaffolds could serve as building blocks in designing drug-like molecules for mTOR inhibition.
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A crystal structure-guided rational design switching non-carbohydrate inhibitors' specificity between two ?-GlcNAcase homologs.
Sci Rep
PUBLISHED: 08-26-2014
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Selective inhibition of function-specific ?-GlcNAcase has great potential in terms of drug design and biological research. The symmetrical bis-naphthalimide M-31850 was previously obtained by screening for specificity against human glycoconjugate-lytic ?-GlcNAcase. Using protein-ligand co-crystallization and molecular docking, we designed an unsymmetrical dyad of naphthalimide and thiadiazole, Q2, that changes naphthalimide specificity from against a human glycoconjugate-lytic ?-GlcNAcase to against insect and bacterial chitinolytic ?-GlcNAcases. The crystallographic and in silico studies reveal that the naphthalimide ring can be utilized to bind different parts of these enzyme homologs, providing a new starting point to design specific inhibitors. Moreover, Q2-induced closure of the substrate binding pocket is the structural basis for its 13-fold increment in inhibitory potency. Q2 is the first non-carbohydrate inhibitor against chitinolytic ?-GlcNAcases. This study provides a useful example of structure-based rationally designed inhibitors as potential pharmaceuticals or pesticides.
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[Study on the heterogeneity of edema in severe preeclampsia].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-22-2014
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The aim of this study was to analysis the clinical edema forms and explore the heterogeneity of edema in severe preeclampsia (PE) .
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Role of the Akt/GSK-3?/CRMP-2 pathway in axon degeneration of dopaminergic neurons resulting from MPP+ toxicity.
Brain Res.
PUBLISHED: 08-21-2014
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Parkinson?s disease (PD) is the most common neurodegenerative disease of the basal ganglia. Earlier reports suggest that the main pathological change in PD is due to apoptosis of dopaminergic neuronal soma in the substantia nigra (SN). The therapies for PD are also largely focused on the prevention of degeneration of the neuronal soma. However, these treatments can only provide temporary relief by delaying the progression of the disease and are therefore unable to prevent the long term neurodegeneration process. This limitation of the existing therapeutic treatment indicates that there may be other causes that either occur earlier or are independent of apoptosis of neuronal soma. Previous studies have shown that axon degeneration may play an important role in PD, and that this may occur at an early stage of the disease. Thus, preventing axon degeneration may be a potential new approach for therapeutic treatment for PD and future therapies can be useful if emphasis is given on the mechanisms of axon degeneration. It has been recognized that microtubule disassembly leads to axon degeneration because the depolymerized microtubules are more likely to be degraded. Previous studies have shown that glycogen synthase kinase-3? (GSK-3?)/collapsin response mediator protein 2 (CRMP-2) signaling pathway could be regulated by Akt for axonal-dendritic polarity. CRMP-2 is critical for specifying axon/dendrite fate possibly by promoting neurite elongation via microtubule assembly. However, whether Akt could regulate GSK-3?/CRMP-2 pathway and the possible effects of this regulation is unclear in dopaminergic axon degeneration induced by 1-methyl-4-phenylpyridiniumion (MPP+). In this study, we observe the degeneration of axon and neuronal soma by scanning electron microscope and tyrosine hydroxylase staining (TH) using a PD model in dopaminergic neurons in vitro. In addition to this, we detect the expression of total and phosphorylated form of Akt, GSK-3? and CRMP-2, as well as the axonal injury marker amyloid precursor protein (APP). From our studies, we observe that axon degeneration is a characteristic feature in the cascade of events that follow when neurons are induced by MPP+. This degeneration process occurs earlier in case of PD and is more severe than the degeneration of the neuronal soma and Akt/ GSK-3?/CRMP-2 pathway is involved in this process.
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Slow magnetic relaxation in a mononuclear eight-coordinate cobalt(II) complex.
J. Am. Chem. Soc.
PUBLISHED: 08-20-2014
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The quest for the single-molecular magnets (SMMs) based on mononuclear transition-metal complexes is focused on the low-coordinate species. No transition-metal complex with a coordination number of eight has been shown to exhibit SMM properties. Here the magnetic studies have been carried out for a mononuclear, eight-coordinate cobalt(II)-12-crown-4 (12C4) complex [Co(II)(12C4)2](I3)2(12C4) (1) with a large axial zero-field splitting. Magnetic measurements show field-induced, slow magnetic relaxation under an applied field of 500 Oe at low temperature. The magnetic relaxation time ? was fitted by the Arrhenius model to afford an energy barrier of Ueff = 17.0 cm(-1) and a preexponential factor of ?0 = 1.5 × 10(-6) s. The work here presents the first example of the eight-coordinate, mononuclear, 3d metal complex exhibiting the slow magnetic relaxation.
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Multi-component assembly and luminescence tuning of lanthanide hybrids based with both zeolite L/A and SBA-15 through two organically grafted linkers.
Dalton Trans
PUBLISHED: 08-19-2014
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Both zeolite A/L and SBA-15 have been used to assemble novel photofunctional multi-component lanthanide hybrid materials. Microporous zeolites A/L are first functionalized by embedding lanthanide or zinc complexes (TTA = thenoyltrifluoroacetone, TAA = trifluoroacetone, bipy = 2,2'-bipyridyl) into the pores of zeolite A/L, and then the surface of functionalized zeolite A/L is modified via covalent linkers from aromatic carboxylic acids (para-aminobenzoic acid ABA and para-hydroxyl benzoic acid HBA) grafted by 3-(triethoxysilyl)-propyl isocyanate (TEPIC). On the other hand, SBA-15 is modified by grafting covalent linker phen-Si from the modification of 1,10-phenanthroline (phen) with TEPIC. Further, another lanthanide ion is used to link both functionalized zeolites, A/L and SBA-15, through the coordination with the two covalent linkers, ABS-Si (HBA-Si) and phen-Si, respectively. Subsequently, the obtained multicomponent microporous-mesoporous hybrid materials are assembled and characterized using XRD, FT-IR, UV-vis DRS, SEM, TEM and luminescent approaches (spectra, lifetimes and quantum efficiencies). These hybrids with both microporous zeolite and SBA-15 mesoporous host possess favourable luminescent performance and some hybrid systems present the high quantum efficiencies of 90%. Besides, the luminescent color can be tuned by adjusting the composition of these hybrids, among which four hybrids (S-phen-Eu-HBA-[ZA-Tb-bipy], S-phen-Eu-HBA-[ZA-Zn-bipy], S-phen-Eu-ABA-[ZA-Tb-TAA], S-phen-Eu-ABA-[ZL-Tb-bipy]) can be integrated to white light emission.
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7,8-dihydroxyflavone protects PC12 cells against 6-hydroxydopamine-induced cell death through modulating PI3K/Akt and JNK pathways.
Neurosci. Lett.
PUBLISHED: 08-17-2014
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We have recently shown that 7,8-dihydroxyflavone (7,8-DHF) protects PC12 cells against 6-OHDA-induced cytotoxicity through its antioxidant activity. In the present study, we investigated the molecular mechanisms underlying the neuronal protective activity of 7,8-DHF. Western blot analysis showed that 6-OHDA (100?M, 24h) enhanced the phosphorylation of JNK and ERK1/2, but it markedly suppressed the expression of p-Akt, implying that 6-OHDA induces PC12 cell death through activating the pro-apoptotic MAPKs pathway but suppressing the survival PI3K/Akt pathway. More importantly, addition of 7,8-DHF fully prevented the activation of JNK and suppression of Akt induced by 6-OHDA. Interestingly, pretreatment with the PI3K-specific inhibitor LY294002 largely blocked 7,8-DHF function in protecting PC12 cells from 6-OHDA-induced cell death. In contrast, the MEK inhibitor PD98059 showed little effect on the protective activity of 7,8-DHF. These results suggest that 7,8-DHF might protect PC12 cells from 6-OHDA-induced cell death through activating PI3K/Akt pathway and inhibiting JNK pathway.
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Functional interleukin-21 polymorphism is a protective factor of diffuse large B-cell lymphoma.
DNA Cell Biol.
PUBLISHED: 08-15-2014
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Interleukin-21 (IL-21) is a recently discovered cytokine and plays critical roles in antitumor immune responses. Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. In this study, we investigated the association between IL-21 genetic polymorphisms and the susceptibility to DLBCL, and the possible functions of these polymorphisms. Two IL-21 polymorphisms, rs907715G/A and rs2221903A/G, were examined in 212 DLBCL patients and 232 healthy controls. Data showed that percentages of rs907715GA and AA genotypes were significantly lower in patients than in controls (odds ratio [OR]=0.60, 95% confidence interval [CI]: 0.40-0.90, p=0.014; OR=0.31, 95% CI: 0.17-0.56, p<0.001, respectively). Frequency of the rs2221903A/G polymorphism did not reveal any significant differences between patients and healthy donors. Further analyses demonstrated a significantly decreased number of rs907715AA genotype in patients with advanced Ann Arbor stages (III+IV). Moreover, we investigated the correlation between IL-21 polymorphisms and serum level of IL-21. Results showed that subjects carrying rs907715AA had significantly increased level of IL-21 than those with GG genotype or GA genotype. These data suggest that rs907715G/A polymorphism may act as a protective factor of DLBCL and might affect the serum level of IL-21.
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Evaluation of ghrelin level and appetite regulation in patients with acute exacerbations of chronic obstructive pulmonary disease.
Int J Chron Obstruct Pulmon Dis
PUBLISHED: 08-14-2014
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Appetite reduction is a major cause of cachexia in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). This study tested the correlation of appetite and circulating levels of acylated ghrelin in patients with AECOPD.
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Metabolomic and network analysis of astaxanthin-producing Haematococcus pluvialis under various stress conditions.
Bioresour. Technol.
PUBLISHED: 08-10-2014
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Various combinations of acetate (Ac), Fe(2+) and high light (HL) stress conditions were evaluated to maximize astaxanthin accumulation and biomass production in Haematococcus pluvialis, and then GC-MS and LC-MS based metabolomics were applied to determine molecular mechanisms responsible for enhancing astaxanthin accumulation under the stress conditions. With the optimized analytical protocols, the GC-MS and LC-MS analyses allowed identification of 93 stable and 24 unstable intracellular metabolites from H. pluvialis, respectively. In addition, a metabolic network was constructed based on GC-MS metabolomic datasets using a weighted correlation network analysis (WGCNA) approach. The network analysis uncovered 2, 1 and 1 distinguished metabolic modules highly associated with HL, Fe(2+) & HL, and Ac & Fe(2+) & HL conditions, respectively. Finally, LC-MS analysis found that AKG, Glu and R5P may be metabolites associated with the Fe(2+) & HL condition. The study provided the first metabolomic view of cell growth and astaxanthin accumulation in H. pluvialis.
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Effects of the joint exposure of decabromodiphenyl ether and tetrabromobisphenol A on soil bacterial community structure.
Environ Sci Pollut Res Int
PUBLISHED: 08-10-2014
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Decabromodiphenyl ether (BDE209) and tetrabromobisphenol A (TBBPA) are the main contaminants at electronic waste (e-waste) recycling sites (EWRSs), and their potential toxicological effects have received extensive attention. However, the impact on soil microorganism of joint exposure to the two chemicals remains almost unknown. Therefore, indoor incubation tests were performed on control and contaminated soil samples to determine the response of soil bacterial community structure in the joint presence of BDE209 and TBBPA for the first time. The results have demonstrated that the soil bacterial diversity generally declined with increasing BDE209 and TBBPA concentrations and moderate and high doses of both chemicals can cause inhibitory effects. PCR-DGGE analysis indicated that the correlations between Shannon-Weaver index and contaminant concentrations could be well represented by a second-order polynomial model. The combined toxicity of the two chemicals was antagonistic during the first 14 days and then synergistic. Pectobacterium carotovorum, Sinorhizobium fredii HH103, and Stenotrophomonas maltophilia were highly tolerant to joint exposure during the entire incubation period. Moreover, some Staphylococcus strains were enriched after 90 days exposed to TBBPA or low concentrations of BDE209, indicating that they might degrade the two chemicals effectively. The results of these observations have provided some basic understanding of potential ecological effects of joint exposure to BDE209 and TBBPA on soil microorganism at EWRSs.
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Response monitoring, tolerability, and effectiveness of imatinib treatment for chronic myeloid leukemia in a retrospective research database.
J Natl Compr Canc Netw
PUBLISHED: 08-08-2014
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Retrospective review of imatinib monitoring through electronic health records (EHR) can provide valuable insight into the current management of chronic myelogenous leukemia (CML). This study retrospectively reviewed EHRs from 2001 to 2010 of patients with chronic phase CML (CP-CML) treated with first-line imatinib. Chart evaluations included a review of cytogenetic and molecular testing, overall survival, adverse drug events (ADEs), and therapy modifications. A total of 54 patients with CP-CML were treated with first-line imatinib and had either cytogenetic or molecular testing within 18 months of imatinib initiation. Within the first 18 months of treatment, 33 of 45 patients (73%) undergoing cytogenetic testing experienced a complete cytogenetic response (median, 241 days; range, 110-542 days) and 24 of 48 patients (50%) receiving molecular testing achieved at least a major molecular response (median, 253 days; range, 99-546 days). The average number of cytogenetic and molecular tests conducted within the first 18 months was 2.5 and 3.8, respectively. Nineteen of 54 (35%) had a dose increase of imatinib (>400 mg; median, 329 days; range, 21-1968 days). The 5-year estimated overall survival rate was 88.5%. Between 2006 and 2010 (n=30; 56%), 7 patients (23%) transitioned to dasatinib or nilotinib (median, 399 days from diagnosis; range, 180-1046 days) because of suboptimal response or treatment failure (n=5) and imatinib ADEs (n=2). Forty-six imatinib-associated ADEs occurred in 31 patients (57%), of which 10 (32%) received dose reductions (median, 52 days) and 6 (19%) had discontinuations (median, 139 days). Closely monitored patients with CML treated with imatinib at an NCCN Member Institution experienced outcomes comparable to those reported in key clinical trials.
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Involvement of Anandamide Transporter in Calcitonin Gene-related Peptide Expression Stimulated by Nitroglycerin and Influence of ALDH2 Glu504Lys Polymorphism.
J. Cardiovasc. Pharmacol.
PUBLISHED: 08-08-2014
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: The aim of this study was to investigate whether N-arachidonic acid ethanolamine (anandamide, AEA) transporter contributed to calcitonin gene-related peptide (CGRP) expression mediated by nitroglycerin (GTN) in peripheral blood mononuclear cells (PBMCs) of healthy volunteers and its association with the mitochondrial aldehyde dehydrogenase-2 (ALDH2) Glu504Lys (ALDH2*2) polymorphism. In 10 ALDH2*2-genotyped Chinese volunteers, we assessed the activity of AEA transporter and expression of CGRP messenger ribonucleic acid (mRNA) in cultured PBMCs treated with different concentration of GTN with or without pretreatment with AM404 (the AEA transporter blocker). In this study, the activity of AEA transporter and expression of CGRP mRNA elevated with the increase in the concentration of GTN. Pretreatment of the cells with AM404 (1 ?M) 2 hours before GTN reduced the GTN-induced increase in both AEA transporter activity and CGRP mRNA expression significantly, and cells with the ALDH2*1/*1 homozygote genotype showed significantly higher activity of AEA transporter and CGRP mRNA expression than carriers of the ALDH2*2 allele. Therefore, we strongly suggested that GTN can stimulate CGRP expression by elevating the AEA transporter activity, which is affected by ALDH2 Glu504Lys polymorphism.
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Structure and dynamics of AMPA receptor GluA2 in resting, pre-open, and desensitized states.
Cell
PUBLISHED: 08-07-2014
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Ionotropic glutamate receptors (iGluRs) mediate the majority of fast excitatory signaling in the nervous system. Despite the profound importance of iGluRs to neurotransmission, little is known about the structures and dynamics of intact receptors in distinct functional states. Here, we elucidate the structures of the intact GluA2 AMPA receptor in an apo resting/closed state, in an activated/pre-open state bound with partial agonists and a positive allosteric modulator, and in a desensitized/closed state in complex with fluorowilliardiine. To probe the conformational properties of these states, we carried out double electron-electron resonance experiments on cysteine mutants and cryoelectron microscopy studies. We show how agonist binding modulates the conformation of the ligand-binding domain "layer" of the intact receptors and how, upon desensitization, the receptor undergoes large conformational rearrangements of the amino-terminal and ligand-binding domains. We define mechanistic principles by which to understand antagonism, activation, and desensitization in AMPA iGluRs.
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X-ray structures of AMPA receptor-cone snail toxin complexes illuminate activation mechanism.
Science
PUBLISHED: 08-07-2014
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AMPA-sensitive glutamate receptors are crucial to the structural and dynamic properties of the brain, to the development and function of the central nervous system, and to the treatment of neurological conditions from depression to cognitive impairment. However, the molecular principles underlying AMPA receptor activation have remained elusive. We determined multiple x-ray crystal structures of the GluA2 AMPA receptor in complex with a Conus striatus cone snail toxin, a positive allosteric modulator, and orthosteric agonists, at 3.8 to 4.1 angstrom resolution. We show how the toxin acts like a straightjacket on the ligand-binding domain (LBD) "gating ring," restraining the domains via both intra- and interdimer cross-links such that agonist-induced closure of the LBD "clamshells" is transduced into an irislike expansion of the gating ring. By structural analysis of activation-enhancing mutants, we show how the expansion of the LBD gating ring results in pulling forces on the M3 helices that, in turn, are coupled to ion channel gating.
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Gene ontology and KEGG enrichment analyses of genes related to age-related macular degeneration.
Biomed Res Int
PUBLISHED: 08-06-2014
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Identifying disease genes is one of the most important topics in biomedicine and may facilitate studies on the mechanisms underlying disease. Age-related macular degeneration (AMD) is a serious eye disease; it typically affects older adults and results in a loss of vision due to retina damage. In this study, we attempt to develop an effective method for distinguishing AMD-related genes. Gene ontology and KEGG enrichment analyses of known AMD-related genes were performed, and a classification system was established. In detail, each gene was encoded into a vector by extracting enrichment scores of the gene set, including it and its direct neighbors in STRING, and gene ontology terms or KEGG pathways. Then certain feature-selection methods, including minimum redundancy maximum relevance and incremental feature selection, were adopted to extract key features for the classification system. As a result, 720 GO terms and 11 KEGG pathways were deemed the most important factors for predicting AMD-related genes.
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Effects of histamine on ciliary beat frequency of ciliated cells from guinea pigs nasal mucosa.
Eur Arch Otorhinolaryngol
PUBLISHED: 08-04-2014
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We aimed to investigate the effect of histamine on ciliary beat frequency (CBF) through combining high-speed digital microscopy and patch-clamp technology. Ciliated cells were obtained from septum and turbinate of 90-120-day-old healthy male guinea pigs. Tight seal was formed by applying negative pressure on the glass electrode after the drawing and pushing progress. Then, we enrolled high-speed digital microscopy to measure CBF before and after treatment with histamine of different concentrations ranging from 10(-6) to 10(-1) mol/L in Hank's solution and D-Hank's solution as well as after administrating adenosine triphosphate. One-way ANOVA, Student's t test or Kruskal-Wallis test was used for statistical comparisons. Glass electrode fix up ciliated cell is available at tip diameter of 2-5 ?m and negative pressure of 10-20 cmH2O column. The baseline CBF in Hank's solution was higher than in D-Hank's solution. Treatment with 10(-6)-l0(-3) mol/L histamine of concentrations can stimulate a rise of CBF. Nevertheless, CBF in all groups decreased to baseline CBF within 20 min. Generally, 10(-2) mol/L histamine can stimulate a rise of CBF; meanwhile, the high concentration of histamine killed 50 % ciliated cell. Histamine at 10(-1) mol/L killed all ciliated cells. Ciliary beating activity decreased in Ca(2+)-free solution. Moreover, adenosine triphosphate could increase CBF effectively after the stimulation effect of histamine. We construct an effective technology integrating patch-clamp technique with CBF measurements on ciliated cells. Extracellular histamine stimulation could increase CBF effectively.
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Activation of Transient Receptor Potential Vanilloid 4 is Involved in Neuronal Injury in Middle Cerebral Artery Occlusion in Mice.
Mol. Neurobiol.
PUBLISHED: 07-29-2014
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Transient receptor potential vanilloid 4 (TRPV4) is widely expressed in the central nervous system and can be activated by multiple stimuli during cerebral ischemia. Recently, we reported that intracerebroventricular (icv.) injection of HC-067047, a specific TRPV4 antagonist, reduced brain infarction following 60-min of middle cerebral artery occlusion (MCAO). This study was undertaken to investigate the molecular mechanisms underlying TRPV4-mediated neuronal injury in cerebral ischemia. We demonstrated that TRPV4 expression was upregulated in the ipsilateral hippocampus at 4 to 48 h post-MCAO, peaking at 18 h post-MCAO. Treatment with TRPV4 antagonists (HC-067047 and ruthenium red) dose-dependently reduced brain infarction at 24 h post-MCAO. Phosphorylation of protein kinase B (p-Akt) was downregulated and that of extracellular signal-related kinase (p-ERK) was upregulated at 8 to 24 h post-MCAO, which was markedly blocked by treatment with HC-067047. Icv. injection of GSK1016790A (a TRPV4 agonist), dose-dependently induced hippocampal neuronal death, accompanied by an increase in phosphorylation of the NR2B subunit of the N-methyl-D-aspartate receptor (NMDAR). In addition, the level of p-Akt was decreased and that of p-ERK was increased by GSK1016790A-injection, which was sensitive to an NR2B antagonist. The neuronal toxicity of GSK1016790A was blocked by treatment with an NR2B antagonist and a phosphatidylinositol-3-kinase (PI3K) agonist but not by administration of a MAPK/ERK kinase antagonist. We conclude that the activation of TRPV4 is upregulated and involved in neuronal injury during cerebral ischemia and that the neurotoxicity associated with TRPV4-activation is mediated through NR2B-NMDAR and the related downregulation of the Akt signaling pathway.
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Controllable preparation of Ni nanoparticles for catalysis of coiled carbon fibers growth.
Nanoscale Res Lett
PUBLISHED: 07-29-2014
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The mass preparation of high-purity coiled carbon fibers (CCFs) remains challenging due to the high complexity and low controllability of reaction. In this work, a controllable growth of Ni particles was fulfilled by liquid phase reduction of nickel sulfate with hydrazine hydrate. The impacts of the reaction temperature, NaOH concentration, and reaction time on the particle size and purity were investigated. The as-deposited Ni particles were characterized by scanning electron microscopy and X-ray diffraction. In addition, these Ni particles were also applied in preparing high-purity CCFs both on graphite and ceramic substrates. The diameter of the as-grown carbon microcoil was about 500 nm, and the related growth mechanism was discussed.
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Characterization and high expression of recombinant Ustilago maydis xylanase in Pichia pastoris.
Biotechnol. Lett.
PUBLISHED: 07-11-2014
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A recombinant xylanase gene (rxynUMB) from Ustilago maydis 521 was expressed in Pichia pastoris, and the enzyme was purified and characterized. Phylogenetic analysis demonstrated that rxynUMB belongs to glycosyl hydrolase family 11. The Trp84, Trp95, Glu93, and Glu189 residues are proposed to be present at the active site. The apparent molecular mass of the recombinant xylananse was approximately 24 kDa, and the optimum pH and temperature were 4.3 and 50 °C, respectively. Xylanase activity was enhanced by 166 and 115 % with Fe(2+) and Mn(2+), respectively. The biochemical properties of this recombinant xylanase suggest that it may be a useful candidate for a variety of commercial applications.
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Cell differentiation and germ-soma separation in Ediacaran animal embryo-like fossils.
Nature
PUBLISHED: 07-01-2014
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Phosphorites of the Ediacaran Doushantuo Formation (?600 million years old) yield spheroidal microfossils with a palintomic cell cleavage pattern. These fossils have been variously interpreted as sulphur-oxidizing bacteria, unicellular protists, mesomycetozoean-like holozoans, green algae akin to Volvox, and blastula embryos of early metazoans or bilaterian animals. However, their complete life cycle is unknown and it is uncertain whether they had a cellularly differentiated ontogenetic stage, making it difficult to test their various phylogenetic interpretations. Here we describe new spheroidal fossils from black phosphorites of the Doushantuo Formation that have been overlooked in previous studies. These fossils represent later developmental stages of previously published blastula-like fossils, and they show evidence for cell differentiation, germ-soma separation, and programmed cell death. Their complex multicellularity is inconsistent with a phylogenetic affinity with bacteria, unicellular protists, or mesomycetozoean-like holozoans. Available evidence also indicates that the Doushantuo fossils are unlikely crown-group animals or volvocine green algae. We conclude that an affinity with cellularly differentiated multicellular eukaryotes, including stem-group animals or algae, is likely but more data are needed to constrain further the exact phylogenetic affinity of the Doushantuo fossils.
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Interleukin-1B-31T/C promoter polymorphism and chronic obstructive pulmonary disease risk: a meta-analysis.
Arch Med Sci
PUBLISHED: 06-27-2014
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The role of interleukin (IL)-1? -31T/C promoter polymorphism in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been studied with inconsistent results. This meta-analysis was performed to assess the association of IL-1? -31T/C promoter polymorphism with COPD susceptibility.
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Structural insights into the negative regulation of BRI1 signaling by BRI1-interacting protein BKI1.
Cell Res.
PUBLISHED: 06-26-2014
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Brassinosteroids (BRs) are essential steroid hormones that have crucial roles in plant growth and development. BRs are perceived by the cell-surface receptor-like kinase brassinosteroid insensitive 1 (BRI1). In the absence of BRs, the cytosolic kinase domain (KD) of BRI1 is inhibited by its auto-inhibitory carboxyl terminus, as well as by interacting with an inhibitor protein, BRI1 kinase inhibitor 1 (BKI1). How BR binding to the extracellular domain of BRI1 leads to activation of the KD and dissociation of BKI1 into the cytosol remains unclear. Here we report the crystal structure of BRI1 KD in complex with the interacting peptide derived from BKI1. We also provide biochemical evidence that BRI1-associated kinase 1 (BAK1) plays an essential role in initiating BR signaling. Steroid-dependent heterodimerization of BRI1 and BAK1 ectodomains brings their cytoplasmic KDs in the right orientation for competing with BKI1 and transphosphorylation.
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Epithelioid angiosarcoma of the kidney: A case report and literature review.
Oncol Lett
PUBLISHED: 06-26-2014
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Epithelioid angiosarcoma (EAS) is a rare disease which presents a great diagnostic challenge. The present study reports a case of EAS in the kidney in a 75-year-old male who presented with gross hematuria. An abdominal computed tomography scan revealed space-occupying lesions of the right kidney and renal cell carcinoma was suspected. Histological examination of the resected specimens showed pleomorphic epithelioid cells with vesicular nuclei, prominent nucleoli and eosinophilic cytoplasm that lined irregular vascular spaces. Immunohistochemical staining revealed that the tumor cells were positive for AE1/AE3, cytokeratin (CK) 7, vimentin, cluster of differentiation (CD) 31 and E-cadherin, but showed no staining for CD10, CD34, factor VIII, CK20, carcinoembryonic antigen or desmin. Based on the histopathological and immunohistochemical findings, the patient was diagnosed with epithelioid angiosarcoma. Postoperative radiation therapy was administered and no recurrence was observed six months after surgery.
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Synthesis and antibacterial activities of antibacterial peptides with a spiropyran fluorescence probe.
Sci Rep
PUBLISHED: 06-25-2014
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In this report, antibacterial peptides1-3 were prepared with a spiropyran fluorescence probe. The probe exhibits a change in fluorescence when isomerized from a colorless spiro-form (spiropyran, Sp) to a colored open-form (merocyanine, Mc) under different chemical environments, which can be used to study the mechanism of antimicrobial activity. Peptides 1-3 exhibit a marked decrease in antimicrobial activity with increasing alkyl chain length. This is likely due to the Sp-Mc isomers in different polar environments forming different aggregate sizes in TBS, as demonstrated by time-dependent dynamic light scattering (DLS). Moreover, peptides 1-3 exhibited low cytotoxicity and hemolytic activity. These probe-modified peptides may provide a novel approach to study the effect of structural changes on antibacterial activity, thus facilitating the design of new antimicrobial agents to combat bacterial infection.
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Biomimetic study of rolling transport through smooth muscle contraction.
Colloids Surf B Biointerfaces
PUBLISHED: 06-16-2014
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Inspired by the rolling behavior of oosperm through smooth muscle contraction of fallopian tube, a simple biomimetic experiment is devised in order to disclose the possibly mechanical transport mechanism. An interesting experimental observation demonstrates that an elastic strain gradient can be utilized to transport a soft latex bubble on a stretchable substrate by rolling. A corresponding theoretical model is established, in which an elastically three-dimensional bubble contacts adhesively on an elastic substrate subject to strain gradient. The initiation and steady-state energy release rates for such a rolling motion are achieved and analyzed. The influencing factors of rolling are found. The finding may have general implications on designing active transport systems with strain gradient.
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Alterations of microRNAs are associated with impaired growth of MCF-7 breast cancer cells induced by inhibition of casein kinase 2.
Int J Clin Exp Pathol
PUBLISHED: 06-15-2014
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Protein Kinase (casein kinase 2, CK2) is a pleiotropic serine-threonine kinase that is frequently dysregulated in many human tumors; microRNAs (miRNAs) are a class of small noncoding RNAs which play important roles in human cancers. This study aimed to investigate the role of CK2 and miRNA expression in breast cancer.
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Limb salvage surgery following resection of a melanoma: Foot and ankle reconstruction using cutaneous flaps.
Oncol Lett
PUBLISHED: 06-12-2014
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Melanomas affect the foot and ankle region and are associated with a poor prognosis. The aim of the current study was to evaluate the functional and oncological outcomes of salvage surgery using cutaneous flaps for soft tissue reconstruction of the foot and ankle following the extended resection of a melanoma. A retrospective review was conducted to evaluate patients who presented with foot melanoma and underwent salvage surgery and defect reconstruction using three types of cutaneous flap (group S) or amputation (group A) between January 1999 and December 2010 at the First Hospital of Jilin University (Changchun, China). The postoperative mortality, surgical complications, functional outcomes and oncological outcomes were evaluated. Of the 21 patients, 11 were enrolled into group S and 10 were enrolled into group A. The median follow-up time of the patients was 58 months (range, 6-92 months). In group S, a reverse sural neurocutaneous island flap was used in six patients to perform the foot reconstruction, medial plantar flaps were used in four patients and lateral malleolus flaps were used in one patient. All 11 cutaneous flaps survived and provided satisfactory coverage. Only one cutaneous flap showed partial necrosis and required treatment comprising of debridement and regular changes to the wound dressing. The overall survival rate of patients was 65.0% and patients in the two groups experienced similar oncological outcomes. Salvage surgery with cutaneous flap reconstruction was found to be a reliable option for patients presenting with malignant melanoma of the foot and ankle.
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The Morphology and Electrophysiology of the Cochlea of the Miniature Pig.
Anat Rec (Hoboken)
PUBLISHED: 06-04-2014
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Objective: To report the cochlear morphology and electrophysiology of Chinese experimental miniature pigs. Methods: Twenty Chinese experimental miniature pigs were used in this study. Auditory brainstem responses (ABR), cochlear endolymphatic potentials (EP), and the potassium concentrations of cochlear endolymph were recorded. Hair cell morphology was examined using electron microscopy. Results: The capsule of cochlea of the miniature pig has three and one-half turns which contains a 39 mm long membranous labyrinth. The organ of Corti in the labyrinth encompasses three rows of outer hair cells and one row of inner hair cells. The stereocilia of the hair cells in the apical turn of the cochlea were significantly longer than those in the basal turn. The vestibular apparatus consists of three semicircular canals and the otolith organs. The average threshold of the ABR was 35 - 45 dB SPL (n = 20) from 4 to 32 kHz. There was no significant difference in the threshold or latency of the ABR between 1-day-old and 30-day-old miniature pigs. The average EP value was 77.3 ± 14 mV (n = 9) and the average potassium concentration was 147.1 ± 13 mM (n = 5) recorded from the second turn of the cochlea. Conclusion: These studies on the cochlear morphology and electrophysiology of the miniature pigs help to establish the Chinese experimental miniature pig as an animal model for future studies in otology and audiology. This article is protected by copyright. All rights reserved.
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Toxic effects of the joint exposure of decabromodiphenyl ether (BDE209) and tetrabromobisphenol A (TBBPA) on soil microorganism and enzyme activity.
Environ. Toxicol. Pharmacol.
PUBLISHED: 05-29-2014
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Decabromodiphenyl ether (BDE209) and tetrabromobisphenol A (TBBPA) are the main contaminants at e-waste recycling sites, and their potential toxicological effects have received extensive attention. However, the impact on soil culturable microbial population and enzyme activity of joint exposure to the two chemicals remains almost unknown. Therefore, indoor incubation tests were performed on control and contaminated soil samples to determine the eco-toxicological response in the joint presence of BDE209 and TBBPA for the first time. The results have demonstrated some notable toxic effects due to long-term exposure to either or both contaminants. The inhibition ratios of microbial populations increased with incubation time and increasing concentrations of BDE209 or TBBPA following certain dose-response relationships and time-effect trends. The response sensitivity sequence was fungi>bacteria>actinomycete. The influence of the two chemicals on soil enzymes reached peak values on day 7, and highly significant differences (P<0.01) were observed compared to the controls. Urease was more susceptive to the two chemicals than catalase and saccharase activities. Generally, the joint toxicity of both contaminants on soil microbes, catalase or saccharase activities indicated antagonistic effects, while, as for urease activity, addition role was dominant. Such observations have provided the useful information of potential ecological effects of brominated flame retardants contamination in the environment.
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Interleukin-1?/IRAK-1 inflammatory signaling contributes to persistent gankyrin activation during hepatocarcinogenesis.
Hepatology
PUBLISHED: 05-26-2014
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Hepatocellular carcinoma (HCC) is a prototype of inflammation-associated cancer. Oncoprotein Gankyrin, mostly increases in HCC, plays a critical role in HCC development and metastasis. However, the exact mechanism of Gankyrin upregulation in HCC remains unclear. A Gankyrin luciferase reporter was developed to screen potential regulator for Gankyrin from a list of pro-inflammatory cytokines, and IL-1? was found as one of its activators. In clinical pre-malignant and malignant liver diseases samples, enhanced IL-1?/IRAK-1 signaling accompanied by increased Gankyrin was observed. Lower expression of Gankyrin and phospho-IRAK-1 are favorable prognostic markers for HCC. A similar correlation was observed in the diethylnitrosamine (DEN) model of rat hepatocarcinogenesis. The results from Gankyrin reporter activity, real-time PCR, or immunoblot further confirmed the upregulation of Gankyrin by IL-1?/IRAK-1 inflammatory signaling. Moreover, a series of Gankyrin's truncated reporters were constructed, and electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) were performed to analyze the properties of Gankyrin promoter. Mechanistically, the core promoter of Gankyrin contains the binding site of NF-Y family members, which can recruit histone acetyltransferase (HAT) co-activator p300 or CBP to promote Gankyrin transcription. Conversely, knockdown of NF-Y, p300, or CBP inhibits Gankyrin expression. IL-1? stimulation causes sequential phosphorylation of IRAK-1, c-Jun N-terminal kinase (JNK) and p300, and enhances the recruitment of the p300/CBP/NF-Y complex to Gankyrin promoter. Inhibition of phospho-JNK impairs IL-1?/IRAK-1 signaling-mediated upregulation of Gankyrin. Thus, the finding of IL-1?/IRAK-1 signaling promoting Gankyrin expression via JNK and NF-Y/p300/CBP complex provides a fresh view on inflammation-enhanced hepatocarcinogenesis. (Hepatology 2014;).
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Evaluation of the effects of photodynamic therapy on chronic central serous chorioretinopathy based on the mean choroidal thickness and the lumen area of abnormal choroidal vessels.
Photodiagnosis Photodyn Ther
PUBLISHED: 05-20-2014
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To evaluate the effects of photodynamic therapy (PDT) on chronic central serous chorioretinopathy (CCSC) by measuring the mean choroidal thickness (MCT) and the lumen area of abnormal choroidal vessels (LAACV).
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Identification of putative virulence-associated genes among Haemophilus parasuis strains and the virulence difference of different serovars.
Microb. Pathog.
PUBLISHED: 05-04-2014
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This study was aimed at determining virulence-associated genes among Haemophilus parasuis (H. parasuis) strains, and supplying for the Kielstein-Rapp-Gabrielson serotyping scheme. The subtractive fragments, obtained through suppression subtractive hybridization and reverse Southern blot hybridization, were found to encode genes representative of 7 different functions. PCR was used to investigate the distribution of these fragments in H. parasuis strains isolated from different infection sites in pigs. Mice challenge was then used to analyze the correlationship between subtractive fragments, infection sites and bacterial virulence. Eight weeks old female BALB/c mice (10 mice/group) were inoculated intraperitoneally with 3.0 × 10(9) CFU suspension (0.5 ml/mouse) of H. parasuis strains in PBS. Results indicated that H. parasuis possessed varied virulence even among the same serovar strains. Transcription units hsdR, hsdS, gpT and ompP2, identified from the subtractive fragments, were uniformly expressed in highly virulent strains, while absent in weakly virulent strains, and demonstrated variable degrees of expression in moderately virulent strains. Moreover, H. parasuis strains, isolated from pericardium and heart blood, were all highly virulent strains, while from nasal cavity and joint were moderately or weakly virulent strains. This study indicated that fragments hsdR, hsdS, gpT and ompP2 were associated with the virulence of H. parasuis. The virulence of H. parasuis strains isolated from different infection sites was different. The current research provides a new reference for determining bacterial virulence in different H. parasuis strains.
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Studies on the binding of fulvic acid with transferrin by spectroscopic analysis.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 04-23-2014
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Transferrin has shown potential in the delivery of anticancer drugs into primarily proliferating cancer cells that over-express transferrin receptors. Fulvic acid has a wide range of biological and pharmacological activities which caused widespread concerns, the interaction of fulvic acid with human serum transferrin (Tf) has great significance for gaining a deeper insight about anticancer activities of fulvic acid. In this study, the mechanism of interaction between fulvic acid and Tf, has been investigated by using fluorescence quenching, thermodynamics, synchronous fluorescence and circular dichroism (CD) under physiological condition. Our results have shown that fulvic acid binds to Tf and form a new complex, and the calculated apparent association constants are 5.04×10(8)M(-1), 5.48×10(7)M(-1), 7.38×10(6)M(-1) from the fluorescence quenching at 288K, 298K, and 310K. The thermodynamic parameters indicate that hydrogen bonding and weak van der Waals are involved in the interaction between fulvic acid and Tf. The binding of fulvic acid to Tf causes the ?-helix structure content of the protein to reduce, and resulting that peptide chains of Tf become more stretched. Our results have indicated a mechanism of the interaction between fulvic acid and Tf, which may provide information for possible design of methods to deliver drug molecules via transferrin to target tissues and cells effectively.
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The association between the rs6495309 polymorphism in CHRNA3 gene and lung cancer risk in Chinese: a meta-analysis.
Sci Rep
PUBLISHED: 04-15-2014
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The association between the rs6495309 polymorphism in CHRNA3 gene and lung cancer risk has been studied in Chinese by several number case-control control studies with small number of cases and controls, and these studies might be underpowered to reveal the true association. Thus we sought to investigate the association with the risk of lung cancer by performing a comprehensive meta-analysis on the polymorphism. Five case-control studies were extracted from 3 articles on the polymorphism involving 4608 lung cancer cases and 4617 controls. The results of meta-analysis showed that significant increased risk were found for the polymorphism with the risk of lung cancer in Chinese: OR = 1.47, 95%CI = 1.33-1.63, P < 0.00001 for CC + TC vs. TT; OR = 1.24, 95%CI = 1.07-1.44, P = 0.005 for CC vs. TT + TC; OR = 1.62, 95%CI = 1.32-2.00, P < 0.00001 for CC vs. TT; OR = 1.42, 95%CI = 1.26-1.61, P < 0.00001 for CT vs. TT; OR = 1.42, 95%CI = 1.26-1.61, P < 0.00001. No significant publication bias was found for the five genetic models. Our findings demonstrated that CHRNA3 gene rs6495309 polymorphism might be a risk factor for the development of lung cancer in Chinese.
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Is replacement of the supraclavicular fossa with the lower level classification based on magnetic resonance imaging beneficial in nasopharyngeal carcinoma?
Radiother Oncol
PUBLISHED: 04-07-2014
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To investigate the pattern of lymph node metastasis and treatment outcome after intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC), and assess the possibility of replacing Ho's supraclavicular fossa (SCF) with the lower level (LL; cervical extension below caudal edge of cricoid cartilage) based on magnetic resonance imaging (MRI) as a criterion for N3 disease.
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Human positive coactivator 4 (PC4) is involved in the progression and prognosis of astrocytoma.
J. Neurol. Sci.
PUBLISHED: 03-23-2014
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Astrocytoma is the most common primary brain tumor and it is associated with poor prognosis. Accumulating evidences suggest that certain molecular abnormalities or genetic mutations are associated with its progression and prognosis. Human transcriptional coactivator 4 (PC4), originally identified as a transcriptional coactivator then as a DNA replication and repair factor has been shown to be involved in chromatin organization. Recently, it is reported to function both as tumor suppressor and promoter depending on the cellular settings. In the present study, we for the first time demonstrated that the expression of PC4 in astrocytoma was upregulated as assessed by western blot and immunohistochemical staining. Moreover, elevated PC4 expression was strongly correlated with the progression of astrocytoma. Furthermore, high PC4 expression was also associated with poor overall survival. Finally, in vitro study demonstrated that siRNA mediated PC4 downregulation significantly inhibited the proliferation and invasiveness of human glioma cells. These results suggested that PC4 might play a role in human astrocytoma progression and may be used as a novel indicator for the prognosis of astrocytoma patient.
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Long noncoding RNA MALAT1 promotes brain metastasis by inducing epithelial-mesenchymal transition in lung cancer.
J. Neurooncol.
PUBLISHED: 03-01-2014
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Brain metastasis often has a poor prognosis in patients with advanced non-small cell lung cancer (NSCLC). Therefore, it is urgent to identify factors associated with lung cancer brain metastasis. Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) also known as noncoding nuclear-enriched abundant transcript 2 is a long noncoding RNA, which is highly conserved amongst mammals. It has been shown to be increased in a variety of tumors including NSCLC and regulate the expression of metastasis-associated genes. However, the role of MALAT1 in lung cancer brain metastasis has not been investigated. In this study, we examined the level of MALAT1 in 78 cases of NSCLC samples with 19 brain metastasis and 59 non-brain metastasis by qRT-PCR. We observed that the level of MALAT1 was significantly higher in brain metastasis than that of non brain metastasis samples (P < 0.001). The level of MALAT1 was associated with patients' survival. To investigate the role of MALAT1 in brain metastasis, we established a highly invasive and metastatic cell subline using the brain metastasis lung cancer cell H1915. We found that MALAT1 is increased in highly invasive subline of brain metastasis lung cancer cells. Further functional studies indicate that silencing MALAT1 inhibits highly invasive subline of brain metastasis lung cancer cell migration and metastasis by inducing epithelial-mesenchymal transition (EMT). Therefore, increased level of long noncoding RNA MALAT1 promotes lung cancer brain metastasis by inducing EMT, which may be a promising prognosis factor and therapeutic target to treat lung cancer brain metastasis in future.
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Angiotensin II stimulates canonical TGF-? signaling pathway through angiotensin type 1 receptor to induce granulation tissue contraction.
J. Mol. Med.
PUBLISHED: 01-31-2014
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Hypertrophic scar contraction (HSc) is caused by granulation tissue contraction propagated by myofibroblast and fibroblast migration and contractility. Identifying the stimulants that promote migration and contractility is key to mitigating HSc. Angiotensin II (AngII) promotes migration and contractility of heart, liver, and lung fibroblasts; thus, we investigated the mechanisms of AngII in HSc. Human scar and unwounded dermis were immunostained for AngII receptors angiotensin type 1 receptor (AT1 receptor) and angiotensin type 2 receptor (AT2 receptor) and analyzed for AT1 receptor expression using Western blot. In vitro assays of fibroblast contraction and migration under AngII stimulation were conducted with AT1 receptor, AT2 receptor, p38, Jun N-terminal kinase (JNK), MEK, and activin receptor-like kinase 5 (ALK5) antagonism. Excisional wounds were created on AT1 receptor KO and wild-type (WT) mice treated with AngII?±?losartan and ALK5 and JNK inhibitors SB-431542 and SP-600125, respectively. Granulation tissue contraction was quantified, and wounds were analyzed by immunohistochemistry. AT1 receptor expression was increased in scar, but not unwounded tissue. AngII induced fibroblast contraction and migration through AT1 receptor. Cell migration was inhibited by ALK5 and JNK, but not p38 or MEK blockade. In vivo experiments determined that absence of AT1 receptor and chemical AT1 receptor antagonism diminished granulation tissue contraction while AngII stimulated wound contraction. AngII granulation tissue contraction was diminished by ALK5 inhibition, but not JNK. AngII promotes granulation tissue contraction through AT1 receptor and downstream canonical transforming growth factor (TGF)-? signaling pathway, ALK5. Further understanding the pathogenesis of HSc as an integrated signaling mechanism could improve our approach to establishing effective therapeutic interventions.
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Quercetin protects against high glucose-induced damage in bone marrow-derived endothelial progenitor cells.
Int. J. Mol. Med.
PUBLISHED: 01-31-2014
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Endothelial progenitor cells (EPCs), a group of bone marrow-derived pro-angiogenic cells, contribute to vascular repair after damage. EPC dysfunction exists in diabetes and results in poor wound healing in diabetic patients with trauma or surgery. The aim of the present study was to determine the effect of quercetin, a natural flavonoid on high glucose?induced damage in EPCs. Treatment with high glucose (40 mM) decreased cell viability and migration, and increased oxidant stress, as was evidenced by the elevated levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase in bone marrow-derived EPCs. Moreover, high glucose reduced the levels of endothelial nitric oxide synthase (eNOS) phosphorylation, nitric oxide (NO) production and intracellular cyclic guanosine monophosphate (cGMP). Quercetin supplement protected against high glucose?induced impairment in cell viability, migration, oxidant stress, eNOS phosphorylation, NO production and cGMP levels. Quercetin also increased Sirt1 expression in EPCs. Inhibition of Sirt1 by a chemical antagonist sirtinol abolished the protective effect of quercetin on eNOS phosphorylation, NO production and cGMP levels following high glucose stress. To the best of our knowledge, the results provide the first evidence that quercetin protects against high glucose?induced damage by inducing Sirt1-dependent eNOS upregulation in EPCs, and suggest that quercetin is a promising therapeutic agent for diabetic patients undergoing surgery or other invasive procedures.
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Omentin-1 promotes the growth of neural stem cells via activation of Akt signaling.
Mol Med Rep
PUBLISHED: 01-13-2014
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Omentin is a novel adipokine, which is expressed in and released from omental adipose tissue. In the present study, the effect of omentin on neural stem cells (NSCs) was investigated. NSCs are a subtype of stem cell in the nervous system, which are able to self?renew and generate neurons and glia for repairing neural lesions. Mouse NSCs were isolated and cultured in vitro. Treatment with recombinant omentin for 3 and 5 days significantly increased the size of NSC neurospheres (P<0.01) and enhanced NSC cell viability in normal conditions. In addition, omentin protected against the decrease in cell viability induced by the pro?inflammatory cytokine tumor necrosis factor??. In the NSCs, incubation of omentin for 2, 4, 6, 8 and 16 h enhanced the phosphorylation of Akt at the Thr308 site and of AS160 at the Ser318 site, peaking 6 h after treatment. Additionally, treatment with LY294002 (10 µM), a specific inhibitor of phosphatidylinositol 3?kinase/Akt signaling, eliminated the omentin?induced increase in neurosphere size and cell viability. Overall, the present study provided the first evidence, to the best of our knowledge, that omentin promotes the growth and survival of NSCs in vitro through activation of the Akt signaling pathway. These results may contribute to the understanding of the role of omentin in the nervous system.
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