994 research outputs found
Protective effects of flavonoids from corn silk on oxidative stress induced by exhaustive exercise in mice
The present study aims at exploring the effects of flavonoids from corn silk (FCS) on oxidative stress induced by exhaustive exercise in mice. Sixty mice were randomized into 3 groups: Low-dose FCS treatment group (LFG), high-dose FCS treatment group (HFG) and control group (CG). The mice were treated with FCS (100 and 400 mg/kg) or placebo (distilled water) by daily oral gavage for 28 days. After the last treatment, animals were submitted to treadmill for exhaustion and running time, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) levels were measured. The results suggested that FCS could elevate the exercise tolerance of mice, and provide protection against oxidative stress induced by exhaustive exercise in mice, by inhibiting lipid per-oxidation and increasing anti-oxidant enzymes levels.Key words: Flavonoids from corn silk, oxidative stress, exhaustive exercise, mic
Hepatitis B Virus Core Promoter Double Mutations (A1762T, G1764A) Are Associated with Lower Levels of Serum Dihydrolipoyl Dehydrogenase
Published by S. Karger AG, BaselObjectives: The aim of this study was to identify serum proteins with differential concentrations between hepatocellular carcinoma (HCC) patients and HBsAg asymptomatic carriers among individuals infected with hepatitis B virus (HBV) with basal core promoter (BCP) double mutations (A1762T, G1764A). Methods: iTRAQ and liquid chromatography-tandem mass spectrometry were used to identify differentially expressed protein, and an ELISA test was used for the validation test. Results: The total number of proteins identified was 1,125, of which 239 showed statistically significant differences in their expression. The relative concentrations of serum dihydrolipoyl dehydrogenase (DLD), which showed the most significant correlation with liver diseases and infection, were significantly lower in HCC patients than asymptomatic HBsAg carriers and individuals negative for HBsAg. However, only the difference between HCC patients with BCP double mutations and HBsAg-negative individuals could be confirmed by ELISA. Meanwhile, we found that the concentrations of serum DLD in those infected with HBV with BCP double mutations were significantly lower than in individuals with the wild-type BCP. However, the difference in the concentrations of serum DLD between individuals with wild-type BCP and those negative for HBsAg was not significant. Conclusions: HBV with BCP double mutations are associated with lower concentrations of serum DLD
Identification and characterization of common carp (Cyprinus carpio L.) granzyme A/K, a cytotoxic cell granule-associated serine protease
Granzyme (Gzm) is an important member of serine protease family, and key component in the specific and non-specific cell-mediated cytotoxicity Partial GzmA/K cDNA sequence of common carp (Cyprinus carpi L) was isolated from thymus cDNA library by the method of suppression subtractive hybridization (SSH). Subsequently, the full length cDNA of carp GzmA/K was obtained by means of 3' RACE and 5' RACE, respectively The full length cDNA of carp GzmA/K was 1053 bp, consisting of a 5'-terminal untranslated region (UTR) of 65 bp, a 3'-terminal UTR of 214 bp, and an open reading frame of 774 bp Amino acid sequence analysis indicated the existence of a signal peptide, eight consensus cysteine residues, one conserved IIGG motif and three conserved residues as central elements of the GzmA/K active site. Carp GzmA/K shared 36% and 39% amino acid identity to human GzmA and K, respectively, and was phylogenetically related to the granzyme A and K subgroups Then, a genomic DNA, which covers the promoter region and entire coding region of carp GzmA/K, was obtained by PCR. In the 5.4 k-long genomic sequence, five exons and four introns were identified. Real-time RT-PCR analysis showed that carp GzmA/K transcript was predominantly detected in the immune-related tissues, and after SVCV infection, was up-regulated in most immune-related tissues in a time-dependent manner Real-time RT-PCR results also showed that carp GzmA/K transcript was up-regulated in thymus tissue of GH transgenic carp These results will help to understand the molecular characterization and the potential role of teleost GzmA/K, a cytotoxic cell granule-associated serine protease Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserve
Vectorial dissipative solitons in vertical-cavity surface-emitting Lasers with delays
We show that the nonlinear polarization dynamics of a vertical-cavity
surface-emitting laser placed into an external cavity leads to the formation of
temporal vectorial dissipative solitons. These solitons arise as cycles in the
polarization orientation, leaving the total intensity constant. When the cavity
round-trip is much longer than their duration, several independent solitons as
well as bound states (molecules) may be hosted in the cavity. All these
solutions coexist together and with the background solution, i.e. the solution
with zero soliton. The theoretical proof of localization is given by the
analysis of the Floquet exponents. Finally, we reduce the dynamics to a single
delayed equation for the polarization orientation allowing interpreting the
vectorial solitons as polarization kinks.Comment: quasi final resubmission version, 12 pages, 9 figure
Investigating antimalarial drug interactions of emetine dihydrochloride hydrate using CalcuSyn-based interactivity calculations
The widespread introduction of artemisinin-based combination therapy has contributed to
recent reductions in malaria mortality. Combination therapies have a range of advantages,
including synergism, toxicity reduction, and delaying the onset of resistance acquisition.
Unfortunately, antimalarial combination therapy is limited by the depleting repertoire of
effective drugs with distinct target pathways. To fast-track antimalarial drug discovery, we
have previously employed drug-repositioning to identify the anti-amoebic drug, emetine
dihydrochloride hydrate, as a potential candidate for repositioned use against malaria.
Despite its 1000-fold increase in in vitro antimalarial potency (ED50 47 nM) compared with
its anti-amoebic potency (ED50 26±32 uM), practical use of the compound has been limited
by dose-dependent toxicity (emesis and cardiotoxicity). Identification of a synergistic partner
drug would present an opportunity for dose-reduction, thus increasing the therapeutic window.
The lack of reliable and standardised methodology to enable the in vitro definition of
synergistic potential for antimalarials is a major drawback. Here we use isobologram and
combination-index data generated by CalcuSyn software analyses (Biosoft v2.1) to define
drug interactivity in an objective, automated manner. The method, based on the median
effect principle proposed by Chou and Talalay, was initially validated for antimalarial application
using the known synergistic combination (atovaquone-proguanil). The combination was
used to further understand the relationship between SYBR Green viability and cytocidal versus
cytostatic effects of drugs at higher levels of inhibition. We report here the use of the
optimised Chou Talalay method to define synergistic antimalarial drug interactivity between
emetine dihydrochloride hydrate and atovaquone. The novel findings present a potential
route to harness the nanomolar antimalarial efficacy of this affordable natural product
Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.
BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721
5-Formylcytosine can be a stable DNA modification in mammals.
5-Formylcytosine (5fC) is a rare base found in mammalian DNA and thought to be involved in active DNA demethylation. Here, we show that developmental dynamics of 5fC levels in mouse DNA differ from those of 5-hydroxymethylcytosine (5hmC), and using stable isotope labeling in vivo, we show that 5fC can be a stable DNA modification. These results suggest that 5fC has functional roles in DNA that go beyond being a demethylation intermediate.This work was supported by the Cancer Research UK (C14303/A17197, S.B.), The Wellcome Trust (WT099232, S.B.; WT095645/Z/11/Z, W.R.) and the BBSRC (BB/K010867/1, W.R.).This is the accepted manuscript. It is currently embargoed pending publication
Mapping Dynamic Histone Acetylation Patterns to Gene Expression in Nanog-depleted Murine Embryonic Stem Cells
Embryonic stem cells (ESC) have the potential to self-renew indefinitely and
to differentiate into any of the three germ layers. The molecular mechanisms
for self-renewal, maintenance of pluripotency and lineage specification are
poorly understood, but recent results point to a key role for epigenetic
mechanisms. In this study, we focus on quantifying the impact of histone 3
acetylation (H3K9,14ac) on gene expression in murine embryonic stem cells. We
analyze genome-wide histone acetylation patterns and gene expression profiles
measured over the first five days of cell differentiation triggered by
silencing Nanog, a key transcription factor in ESC regulation. We explore the
temporal and spatial dynamics of histone acetylation data and its correlation
with gene expression using supervised and unsupervised statistical models. On a
genome-wide scale, changes in acetylation are significantly correlated to
changes in mRNA expression and, surprisingly, this coherence increases over
time. We quantify the predictive power of histone acetylation for gene
expression changes in a balanced cross-validation procedure. In an in-depth
study we focus on genes central to the regulatory network of Mouse ESC,
including those identified in a recent genome-wide RNAi screen and in the
PluriNet, a computationally derived stem cell signature. We find that compared
to the rest of the genome, ESC-specific genes show significantly more
acetylation signal and a much stronger decrease in acetylation over time, which
is often not reflected in an concordant expression change. These results shed
light on the complexity of the relationship between histone acetylation and
gene expression and are a step forward to dissect the multilayer regulatory
mechanisms that determine stem cell fate.Comment: accepted at PLoS Computational Biolog
Synchronization Control for Discrete-Time-Delayed Dynamical Networks with Switching Topology under Actuator Saturations
10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 61773156, 61873148, 61673141 and 61933007); 10.13039/501100018551-Program for Science and Technology Innovation Talents in the Universities of Henan Province of China (Grant Number: 19HASTIT028); 10.13039/501100010029-Research Fund for the Taishan Scholar Project of Shandong Province of China; 10.13039/501100000288-Royal Society of the U.K.; 10.13039/100005156-Alexander von Humboldt Foundation of Germany
Probability-Guaranteed Envelope-Constrained Filtering for Nonlinear Systems Subject to Measurement Outliers
10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 61773209, 61873148, 61933007 and 61673141); Australian Research Council Discovery Project (Grant Number: DP160103567);
10.13039/501100004608-Natural Science Foundation of Jiangsu Province (Grant Number: BK20190021);
10.13039/501100010014-Six Talent Peaks Project in Jiangsu Province (Grant Number: XYDXX-033); Alexander von Humboldt Foundation of Germany
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