Human leukocyte antigen class II DQB1*0301, DRB1*1101 alleles and spontaneous clearance of hepatitis C virus infection: A meta-analysis

AIM: To assess the associations of human leukocyte antigen (HLA) class Ⅱ DQB1*0301 and/or DRB1*1101 allele with spontaneous hepatitis C virus (HCV) clearance by meta-analysis of individual dataset from all studies published till date.METHODS: To clarify the impact of HLA class Ⅱ polymorphisms on viral clearance, we performed a metaanalysis of the published data from 11 studies comparing the frequencies of DQB1*0301 and DRB1*1101 alleles in individuals with spontaneous resolution to those with persistent infection. As we identified the heterogeneity between studies, summary statistical data were calculated based on a random-effect model.RESULTS: Meta-analyses yielded summary estimatesodds ratio (OR) of 2.36 [95%CI (1.62, 3.43), P<0.00001]and 2.02 [95%CI (1.56, 2.62), P<0.00001] for the effects of DQB1*0301 and DRB1*1101 alleles on spontaneous clearance of HCV, respectively.CONCLUSION: These results support the hypothesis that specific HLA class Ⅱ alleles might influence the susceptibility or resistance to persistent HCV infection.Both DQB1*0301 and DRB1*1101 are protective alleles and present HCV epitopes more effectively to CD4+T lymphocytes than others, and subjects with these two alleles are at a lower risk of developing chronic HCV infection. Large, multi-ethnic confirmatory and welldesigned studies are needed to determine the host genetic determinants of HCV infection.

Prevalence of asthenopia and its risk factors in Chinese college students

·AIM: To determine the prevalence of asthenopia and identify any associated risk factors in the college students in Xi’an, China. · METHODS: From April to September 2012, 1 500 students from five universities in Xi’an were selected according to a multi -stage stratified cluster sampling method. Data on demographic features, lifestyle or dietary habits, health status, living environment conditions, sleep and mental status, and asthenopia symptoms were collected through a self -administered validated questionnaire. Univariate logistic regression and multivariate logistic regression analysis modified by the factor analysis were performed to evaluate risk factors for asthenopia. ·RESULTS: Fifty-seven percent of the college students complained of asthenopia. Statistically significant risk factors for asthenopia in the univariate analysis included 13 variables. Multivariate analysis revealed a significant relationship between the use of computer and asthenopia (OR 1.21, 95% CI: 1.09 to 1.35). Good sleep and mental status (OR 0.86, 95% CI: 0.76 to 0.97), good living environment conditions (OR 0.67, 95% CI: 0.60 to 0.76), and high intake of green leafy vegetables (OR 0.89, 95% CI: 0.80 to 0.98) were found to be strong predictors of decreasing the occurrence of asthenopia complaints. ·CONCLUSION: Asthenopia symptom appeares to be common among college students; and it is strongly associated with computer use, psychosocial state, environment conditions and dietary habits, suggesting that additional studies are warranted to verify these risk factors and establish prevention guidelines, especially for college students. ·

Seroepidemiology of hepatitis B virus infection and impact of vaccination

AIM: To investigate hepatitis B virus(HBV) prevalence in the general population in China.METHODS: A total of 148931 individuals were investigated by multistage random sampling in Eastern China. Data were collected on demographics and hepatitis B vaccination history, and serum was tested for hepatitis B surface antigen(HBs Ag) by ELISA. RESULTS: A total of 11469 participants(7.70%, 95%CI: 7.57%-7.84%) were positive for HBs Ag. HBs Ag prevalence was 0.77% among children < 5 years old but increased progressively from adolescents(1.40%-2.55%) to adults(5.69%-11.22%). A decrease in HBs Ag prevalence was strongly associated with vaccination and familial history of HBV among both children and adult groups. Meanwhile, HBs Ag risk in adults was associated with invasive testing and sharing needles. The HBV immunization rate among participants aged < 20 years was 93.30%(95%CI: 93.01%-93.58%). Significant difference in HBs Ag prevalence appeared between vaccinated and unvaccinated participants(3.59% vs 10.22%). CONCLUSION: Although the national goal of HBs Ag prevalence < 1% among children < 5 years old has been reached, immunization programs should be maintained to prevent resurgence.

Epidemiology of hepatitis C virus in Iran

In Iran,the prevalence of hepatitis C virus(HCV) infection is relatively low according to the populationbased epidemiological studies. However,the epidemiology of HCV is changing and the rate of HCV infection is increasing due to the growth in the number of injecting drug users in the society. In addition,a shift has occurred in the distribution pattern of HCV genotypes among HCV-infected patients in Iran. Genotype 1a is the most prevalent genotype in Iran,but in recent years,an increase in the frequency of 3a and a decrease in 1a and 1b have been reported. These variations in the epidemiology of HCV reflect differences in the routes of transmission,status of public health,lifestyles,and risk factors in different groups and geographic regions of Iran. Health policy makers should consider these differences to establish better strategies for control and prevention of HCV infection. Therefore,this review was conducted to present a clear view regarding the current epidemiology of HCV infection in Iran.

Interferon-λ-related genes and therapeutic response in Chinese hepatitis C patients

AIM: To determine the association between rapid viral response and IL28 B, IL28 RA, IL10 RB and Mx A polymorphisms in the Chinese Han population.METHODS: The study cohort consisted of 238 chronic hepatitis C patients treated with interferon(IFN)-α-2b and ribavirin. Six single nucleotide polymorphisms were genotyped using the ABI Taq Man allelic discrimination assay. Biochemical indices were measured at baseline. Serum hepatitis C virus(HCV) RNA was detected at weeks 0, 4, 12 and 24 of therapy.RESULTS: Only IL28 B rs12980275 was associated with treatment response in the Chinese Han population. Patients carrying AG/GG genotypes had a reduced rapid viral response compared with patients carrying the AA genotype(additive model: adjusted OR = 0.43, 95%CI: 0.24-0.75). It took less time for patients with the AA genotype to achieve a viral load < 500 copies/m L(logrank test, P = 0.004). In addition, the protective effect of genotype AA was independent of baseline viral load. HCV genotype, and baseline white blood cell count, α-fetoprotein and viral load might also help predict treatment response. The area under the receiveroperating characteristic curve was 0.726. CONCLUSION: IL28 B rs12980275 AA genotype is a strong predictor of positive response to IFN therapy in Chinese Han patients with hepatitis C.

Cascading failures of overload behaviors using a new coupled network model between edges

With the development of network science,the coupling between networks has become the focus of complex network research.However,previous studies mainly focused on the coupling between nodes,while ignored the coupling between edges.We propose a novel cascading failure model of two-layer networks.The model considers the different loads and capacities of edges,as well as the elastic and coupling relationship between edges.In addition,a more flexible load-capacity strategy is adopted to verify the model.The simulation results show that the model is feasible.Different networks have different behaviors for the same parameters.By changing the load parameters,capacity parameters,overload parameters,and distribution parameters reasonably,the robustness of the model can be significantly improved.