The virulence regulator AbsR in avian pathogenic Escherichia coli has pleiotropic effects on bacterial physiology

Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin production regulation,locus A,herein renamed AbsR,a blood survival regulator),a member of the MarR(multiple antibiotic resistance regulator)transcriptional regulator family,governs the expression of capsule biosynthetic genes in human ExPEC and represents a promising druggable target for antimicrobials.However,a deep understanding of the AbsR regulatory mechanism as well as its regulon is lacking.In this study,we present a systems-level analysis of the APEC AbsR regulon using ChIP-Seq(chromatin immunoprecipitation sequencing)and RNA-Seq(RNA sequencing)methods.We found that AbsR directly regulates 99 genes and indirectly regulates 667 genes.Furthermore,we showed that:1)AbsR contributes to antiphagocytotic effects by macrophages and virulence in a mouse model for systemic infection by directly activating the capsular gene cluster;2)AbsR positively impacts biofilm formation via direct regulation of the T2SS(type II secretion system)but plays a marginal role in virulence;and 3)AbsR directly upregulates the acid tolerance signaling system EvgAS to withstand acid stress but is dispensable in ExPEC virulence.Finally,our data indicate that the role of AbsR in virulence gene regulation is relatively conserved in ExPEC strains.Altogether,this study provides a comprehensive analysis of the AbsR regulon and regulatory mechanism,and our data suggest that AbsR likely influences virulence primarily through the control of capsule production.Interestingly,we found that AbsR severely represses the expression of the type I-F CRISPR(clustered regularly interspaced short palindromic repeats)-Cas(CRISPR associated)systems,which could have implications in CRISPR biology and application.

Evaluating short-term and long-term liver fibrosis improvement in hepatitis C patients after DAA treatment

Despite achieving a high cure rate with the direct-acting antivirals(DAAs)in hepatitis C treatment,further research is needed to identify additional benefits of the DAA therapy.The current study evaluated liver fibrosis improvement in 848 hepatitis C patients treated with DAAs,who also achieved sustained virologic response.By the fibrosis-4(FIB-4)index,patients were categorized based on their baseline fibrosis levels,and the improvement in fibrosis was analyzed in both short-term(9-26 weeks)and long-term(≥36 weeks)follow-up.The results showed a significant decrease in the FIB-4 index,indicating an improvement in liver fibrosis,in 63.0%and 67.6%of the patients during the short-term and long-term follow-up,respectively.Short-term improvement was associated with factors including ribavirin usage,blood cholinesterase levels,alanine transaminase levels,albumin levels,and the baseline FIB-4 index,while long-term improvement was associated with factors such as aspartate transaminase levels,total protein level,and the baseline FIB-4 index.The current study emphasizes the importance of continuous assessment and post-treatment monitoring of liver fibrosis,which will provide crucial insights for enhancing patient care in hepatitis C management.

Epidemiology and natural history of hepatitis C virus infection

Hepatitis C virus(HCV)affects 130-210 million people worldwide and is one of the major risk factors for hepatocellular carcinoma.Globally,at least one third of hepatocellular carcinoma cases are attributed to HCV infection,and 350000 people died from HCV related diseases per year.There is a great geographical variation of HCV infection globally,with risk factors for the HCV infection differing in various countries.The progression of chronic hepatitis C to end-stage liver disease also varies in different study populations.A long-term follow-up cohort enrolling participants with asymptomatic HCV infection is essential for elucidating the natural history of HCV-caused hepatocellular carcinoma,and for exploring potential seromarkers that have high predictability for risk of hepatocellular carcinoma.However,prospective cohorts comprising individuals with HCV infection are still uncommon.The risk evaluation of viral load elevation and associated liver disease/cancer in HCV(REVEAL-HCV)study has followed a cohort of 1095 residents seropositive for antibodies against hepatitis C virus living in seven townships in Taiwan for more than fifteen years.Most of them have acquired HCV infection through iatrogenic transmission routes.As the participants in the REVEALHCV study rarely receive antiviral therapies,it provides a unique opportunity to study the natural history of chronic HCV infection.In this review,the prevalence,risk factors and natural history of HCV infection are comprehensively reviewed.The study cohort,data collection,and findings on liver disease progression of the REVEAL-HCV study are described.

Incidence and risk factors of retinopathy of prematurity and utility of the national screening criteria in a tertiary center in Iran

AIM: To determine the incidence and risk factors of retinopathy of prematurity(ROP) and the sensitivity of current screening criteria in a tertiary eye center in Tehran, Iran. METHODS: In a cross-sectional observational study, neonates weighing ≤2000 grams at birth or born <34 wk gestational age(GA) and all other infants at risk of ROP admitted to the neonatal intensive care unit(NICU) or referred to our ROP clinic were investigated. The incidence of ROP and severe ROP(i.e. patients needing treatment) were determined. The associations between risk factors and the development and severity of ROP were assessed. We also examined the sensitivity of the current national screening guideline in Iran. RESULTS: Among 207 infants, the incidence of ROP and severe ROP was 33.3% and 11.1%, respectively. Mean GA and birth weight(BW) were significantly lower in ROP vs non-ROP infants(29±2 wk vs 33±3 wk, P<0.001;1274±489 g vs 1916±550 g, P<0.001, respectively). Univariate analysis displayed significant association between ROP incidence and GA, BW, NICU admission period, blood transfusion, surfactant usage, sepsis, intraventricular hemorrhage and patent ductus arteriosus(P<0.05 for all). BW [relative risk(RR): 0.857(0.711-0.873), P<0.001], GA [RR: 0.788(0.711-0.873), P<0.001] and blood transfusion [RR: 1.888(0.995-3.583), P=0.052] were independent ROP risk factors. The sensitivity of country-specific screening guidelines was 95.7% and 100% for overall and severe ROP detection, respectively. CONCLUSION: ROP incidence is relatively high in Iran. Identifying ROP risk factors results in more accurate screening and reduces the risk of irreversible vision loss. The ROP screening criteria utilized in Iran are efficient at the present time.

From human genome epidemiology to systems epidemiology:current progress and future perspective

The recent progress in human genome epidemiology(HuGE) is already having a profound impact on the practice of medicine and public health.First,the success of genome-wide association studies has greatly expanded the direction and content of epidemiological researches,including revealing new genetic mechanisms of complex diseases,identifying new targets for therapeutic interventions,and improving application in early screening of high-risk populations.At the same time,large-scale genomic studies make it possible to efficiently explore the gene-environment interactions,which will help better understand the biological pathways of complex diseases and identify individuals who may be more susceptible to diseases.Additionally,the emergence of systems epidemiology aims to integrate multi-omics together with epidemiological data to create a systems network that can comprehensively characterize the diverse range of factors contributing to disease development.These progress will help to apply HuGE findings into practice to improve the health of individuals and populations.

Medical expenditures for colorectal cancer diagnosis and treatment: A 10-year high-level-hospital-based multicenter retrospective survey in China, 2002-2011

Objective: Colorectal cancer(CRC) causes a substantial burden of disease in China and the evidence of economic burden triggered is fundamental for priority setting. The aim of this survey was to quantify medical expenditures and the time trends for CRC diagnosis and treatment in China.Methods: From 2012 to 2014, a hospital-based multicenter retrospective survey was conducted in 13 provinces across China. For each eligible CRC patient diagnosed from 2002 to 2011, clinical information and expenditure data were extracted using a uniform questionnaire. All expenditure data were reported in Chinese Yuan(CNY)using 2011 values.Results: Of the 14,536 CRC patients included, the average age at diagnosis was 58.2 years and 15.8% were stageI cases. The average medical expenditure per patient was estimated at 37,902 CNY [95 % confidence interval(95%CI): 37,282-38,522], and the annual average increase rate was 9.2% from 2002 to 2011(P for trend <0.001), with a cumulative increase of 2.4 times(from 23,275 CNY to 56,010 CNY). The expenditure per patient in stages Ⅰ, Ⅱ, Ⅲ and Ⅳ were 31,698 CNY, 37,067 CNY, 38,918 CNY and 42,614 CNY, respectively(P<0.001). Expenditure significantly differed within various subgroups. Expenses for drugs contributed the largest proportion(52.6%).Conclusions: These conservative estimates illustrated that medical expenditures for CRC diagnosis and treatment in tertiary hospitals in China were substantial and increased rapidly over the 10 years, with drugs continually being the main expense by 2011. Relatively, medical expenditures are lower for CRC in the earlier stages. These findings will facilitate the economic evaluation of CRC prevention and control in China.

Expenditure and financial burden for the diagnosis and treatment of colorectal cancer in China:a hospital.based,multicenter,cross-sectional survey

Background: The increasing prevalence of colorectal cancer(CRC) in China and the paucity of information about relevant expenditure highlight the necessity of better understanding the financial burden and effect of CRC diagnosis and treatment. We performed a survey to quantify the direct medical and non-medical expenditure as well as the resulting financial burden of CRC patients in China.Methods: We conducted a multicenter, cross-sectional survey in 37 tertiary hospitals in 13 provinces across China between 2012 and 2014. Each enrolled patient was interviewed using a structured questionnaire. All expenditure data were inflated to the 2014 Chinese Yuan(CNY; 1 CNY = 0.163 USD). We quantified the overall expenditure and financial burden and by subgroup(hospital type, age at diagnosis, sex, education, occupation, insurance type, household income, clinical stage, pathologic type, and therapeutic regimen). We then performed generalized linear modeling to determine the factors associated with overall expenditure.Results: A total of 2356 patients with a mean age of 57.4 years were included, 57.1 % of whom were men; 13.9% of patients had stage I cancer; and the average previous-year household income was 54,525 CNY.The overall average direct expenditure per patient was estimated to be 67,408 CNY, and the expenditures for stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ disease were 56,099 CNY, 59,952 CNY, 67,292 CNY, and 82,729 CNY, respectively. Non-medical expenditure accounted for 8.3%of the overall expenditure. The 1-year out-of-pocket expenditure of a newly diagnosed patient was 32,649 CNY, which accounted for 59.9% of their previous-year household income and caused 75.0% of families to suffer an unmanageable financial burden. Univariate analysis showed that financial burden and overall expenditure differed in almost all subgroups(P < 0.05), except for sex. Multivariate analysis showed that patients who were treated in specialized hospitals and those who were diagnosed with adenocarcinoma or diagnosed at a later stage were likely to spend more,whereas those with a lower household income and those who underwent surgery spent less(all P < 0.05).Conclusions: For patients in China, direct expenditure for the diagnosis and treatment of CRC seemed catastrophic,and non-medical expenditure was non-ignorable. The financial burden varied among subgroups, especially among patients with different clinical stages of disease, which suggests that, in China, CRC screening might be cost-effective.

Medical expenditure for esophageal cancer in China:a 10-year multicenter retrospective survey(2002-2011)

Background: Esophageal cancer is associated with substantial disease burden in China, and data on the economic burden are fundamental for setting priorities in cancer interventions. The medical expenditure for the diagnosis and treatment of esophageal cancer in China has not been fully quantified. This study aimed to examine the medical expenditure of Chinese patients with esophageal cancer and the associated trends.Methods: From 2012 to 2014, a hospital-based multicenter retrospective survey was conducted in 37 hospitals in 13 provinces/municipalities across China as a part of the Cancer Screening Program of Urban China. For each esophageal cancer patient diagnosed between 2002 and 2011, clinical information and expense data were extracted by using structured questionnaires. All expense data were reported in Chinese Yuan(CNY; 1 CNY = 0.155 USD) based on the2011 value and inflated using the year-specific health care consumer price index for China.Results: A total of 14,967 esophageal cancer patients were included in the analysis. It was estimated that the overall average expenditure per patient was 38,666 CNY, and an average annual increase of 6.27% was observed from 2002(25,111 CNY) to 2011(46,124 CNY). The average expenditures were 34,460 CNY for stage Ⅰ,39,302 CNY for stage Ⅱ,40,353 CNY for stage Ⅲ, and 37,432 CNY for stage IV diseases(P < 0.01). The expenditure also differed by the therapy type, which was 38,492 CNY for surgery, 27,933 CNY for radiotherapy, and 27,805 CNY for chemotherapy(P < 0.05).Drugs contributed to 45.02% of the overall expenditure.Conclusions: These conservative estimates suggested that medical expenditures for esophageal cancer in China substantially increased in the last 10 years, treatment for early-stage esophageal cancer costs less than that for advanced cases, and spending on drugs continued to account for a considerable proportion of the overall expenditure.

Phylogenetic and epidemiological characteristics of H9N2 avian influenza viruses in Shandong Province, China from 2019 to 2021

H9N2 avian influenza virus(AIV) has widely circulated in poultry worldwide and sporadic infections in humans and mammals. During our surveillance of chicken from 2019 to 2021 in Shandong Province, China, we isolated 11 H9N2AIVs. Phylogenetic analyses showed that the eight gene segments of the 11 isolates were closely related to several sublineages of Eurasian lineage: BJ/94-like clades(HA and NA genes), G1-like clades(PB2 and M genes), and SH/F/98-like clades(PB1, PA, NP and NS genes). The isolates showed mutation sites that preferentially bind to humanlike receptors(HA) and mammalian fitness sites(PB2, PB1 and PA), as well as mutations in antigen and drug resistance sites. Moreover, studies with mice revealed four isolates with varying levels of pathogenicity. The average antibody titer of the H9N2 AIVs was 8.60 log2. Based on our results, the epidemiological surveillance of H9N2 AIVs should be strengthened.

Enduring association between irritable bowel syndrome and war trauma during the Nicaragua civil war period:A population-based study

BACKGROUND Psychosocial and physical trauma are known risk factors for irritable bowel syndrome(IBS),including in war veterans,whereas war exposure in civilians is unclear.Nicaragua experienced two wars,1970-1990:The Sandinistas Revolution(1970s)and The Contra War(1980s).Our aim was to investigate the role of exposure to war trauma in the subsequent development of IBS in the context of an established health surveillance system(11000 households).AIM To investigate in a civilian population the relationship between exposure to war trauma and events and the subsequent development of IBS in the context of an established public health and demographic surveillance system in western Nicaragua.METHODS We conducted a nested population-based,cross-sectional study focused on functional gastrointestinal disorders based on Rome II criteria.1617 adults were randomly selected.The Spanish Rome II Modular Questionnaire and Harvard Trauma Questionnaire were validated in Nicaragua.War exposure was assessed with 10 measures of direct and indirect war trauma and post-war effects.Multiple exposures were defined by≥3 measures.RESULTS The prevalence of IBS was 15.2%[Female(F)17.1%,Male(M)12.0%],war exposure 19.3%(F 9.3%,M 36.7%),and post-traumatic stress disorder(PTSD)5.6%(F 6.4%,M 4.3%).Significant associations with IBS in the civilian population were observed(adjusted by gender,age,socioeconomic status,education):physical and psychological abuse[adjusted odds ratio(aOR):2.25;95%confidence interval:1.1-4.5],witnessed execution(aOR:2.4;1.1-5.2),family member death(aOR:2.2;1.2-4.2),and multiple exposures(aOR:2.7;1.4-5.1).PTSD was independently associated with IBS(aOR:2.6;1.2-5.7).CONCLUSION An enduring association was observed in the Nicaragua civilian population between specific civil war-related events and subsequent IBS.Civilian populations in regions with extended armed conflict may warrant provider education and targeted interventions for patients.

Edible mushrooms as a potent therapeutics of subclinical thyroid dysfunction among adults,especially in obese individuals:a prospective cohort study

Background:Mushrooms are a good source of many nutrients which are potentially beneficial for chronic diseases.We speculated that due to its abundant nutrients edible mushrooms might have a beneficial effect on the prevention of subclinical thyroid dysfunction(SCTD).Therefore,we designed a large-scale cohort study to examine whether mushrooms consumption is a protective factor for SCTD in adults.Methods:This prospective cohort study investigated 6631 participants(mean age:(45.0±10.2)years;55.1%men).Edible mushrooms consumption was measured at baseline using a validated food frequency questionnaire.SCTD was defined as abnormal serum thyroid-stimulating hormone levels and normal free thyroxine.Cox proportional hazards regression models were used to examine the association of edible mushrooms consumption with incident SCTD.Results:During follow-up period,a total of 262 new cases of SCTD were identified,the incidence rate of subclinical hypothyroidism was 8.9/1000 person-years and subclinical hyperthyroidism was 7.2/1000 person-years.After adjusting potential confounding factors,the multivariable hazard ratios(95%confidence intervals)for subclinical hypothyroidism were 1.00(reference)for almost never,0.53(0.29,0.97)for 1-3 times/week and 0.30(0.10,0.87)for≥4 times/week(P for trend=0.02).It also showed edible mushrooms consumption was inversely associated with subclinical hypothyroidism in obese individuals but not non-obese individuals,the final hazard ratios(95%confidence intervals)were 0.14(0.03,0.73)(P for trend<0.01).Conclusions:This population-based prospective cohort study has firstly demonstrated that higher edible mushrooms consumption was significantly associated with lower incidence of subclinical hypothyroidism among general adult population,especially in obese individuals.

Association between Fruit and Vegetable Intake and Arterial Stiffness: The China-PAR Project

Objective This study aimed to investigate the association between fruit and vegetable intake and arterial stiffness.Methods We conducted a cohort-based study comprising 6,628 participants with arterial stiffness information in the Prediction for Atherosclerotic Cardiovascular Disease Risk in China(China-PAR)project. A semi-quantitative food-frequency questionnaire was used to assess baseline(2007–2008) and recent(2018–2021) fruit and vegetable intake. We assessed changes in fruit and vegetable intake from2007–2008 to 2018–2021 in 6,481 participants. Arterial stiffness was measured using the arterial velocity–pulse index(AVI) and arterial pressure-volume index(API). Elevated AVI and API values were defined according to diverse age reference ranges.Results Multivariable-adjusted linear regression models revealed that every 100 g/d increment in fruit and vegetable intake was associated with a 0.11 decrease in AVI(B =-0.11;95% confidence interval [CI]:-0.20,-0.02) on average, rather than API(B = 0.02;95% CI:-0.09, 0.13). The risk of elevated AVI(odds ratio [OR] = 0.82;95% CI: 0.70, 0.97) is 18% lower in individuals with high intake(≥ 500 g/d) than in those with low intake(< 500 g/d). Furthermore, maintaining a high intake in the past median of 11.5years of follow-up was associated with an even lower risk of elevated AVI compared with a low intake at both baseline and follow-up(OR = 0.64;95% CI: 0.49, 0.83).Conclusion Fruit and vegetable intake was negatively associated with arterial stiffness, emphasizing recommendations for adherence to fruit and vegetable intake for the prevention of arterial stiffness.

Association of maternal hypertensive disorders in pregnancy with infant neurodevelopment

Inconsistent findings have been reported regarding the associations between hypertensive disorders in pregnancy (HDP) and infant neurodevelopment. Leveraging data from the Jiangsu Birth Cohort, in the present study, we re-visited such associations in one-year-old infants from 2 576 singleton pregnancies and 261 twin pregnancies. We first assessed infant neurodevelopment by the Bayley Scales of Infant and Toddler Development Screening Test (the Third Edition), and then estimated its association with maternal HDP using general linear regression models and Poisson regression models. In singleton pregnancies, compared with mothers unexposed to HDP, infants born to mothers with chronic hypertension exhibited a lower score (β, −0.67;95% confidence interval [CI], −1.19-−0.15) and a higher risk of "non-optimal" gross motor development (risk ratio [RR], 2.21;95% CI, 1.02-4.79);in twin pregnancies, infants born to mothers with HDP exhibited lower scores in cognition (β, −0.49;95% CI, −0.96-−0.01), receptive communication (β, −0.55;95% CI, −1.03-−0.06), and gross motor (β, −0.44;95% CI, −0.86-−0.03), and at a higher risk of "non-optimal" gross motor development (RR, 2.12;95% CI, 1.16-3.88). These findings indicate that infants born to mothers with HDP may have inferior neurodevelopment outcomes at the age of one year.

Key elements and checklist of shared decisionmaking conversation on life-sustaining treatment in emergency:a multispecialty study from China

BACKGROUND:Shared decision-making(SDM)has broad application in emergencies.Most published studies have focused on SDM for a certain disease or expert opinions on future research gaps without revealing the full picture or detailed guidance for clinical practice.This study is to investigate the optimal application of SDM to guide life-sustaining treatment(LST)in emergencies.METHODS:This study was a prospective two-round Delphi consensus-seeking survey among multiple stakeholders at the China Consortium of Elite Teaching Hospitals for Residency Education.Participants were identified based on their expertise in medicine,law,administration,medical education,or patient advocacy.All individual items and questions in the questionnaire were scored using a 5-point Likert scale,with responses ranging from"very unimportant"(a score of 1)to"extremely important"(a score of 5).The percentages of the responses that had scores of 4-5on the 5-point Likert scale were calculated.A Kendall’s W coefficient was calculated to evaluate the consensus of experts.RESULTS:A two-level framework consisting of 4 domains and 22 items as well as a ready-touse checklist for the informed consent process for LST was established.An acceptable Kendall’s W coefficient was achieved.CONCLUSION:A consensus-based framework supporting SDM during LST in an emergency department can inform the implementation of guidelines for clinical interventions,research studies,medical education,and policy initiatives.

Lifestyle improvement and the reduced risk of cardiovascular disease:the China-PAR project

BACKGROUND The benefits of healthy lifestyles are well recognized. However, the extent to which improving unhealthy lifestyles reduces cardiovascular disease(CVD) risk needs to be discussed. We evaluated the impact of lifestyle improvement on CVD incidence using data from the China-PAR project(Prediction for Atherosclerotic Cardiovascular Disease Risk in China).METHODS A total of 12,588 participants free of CVD were followed up for three visits after the baseline examination. Changes in four lifestyle factors(LFs)(smoking, diet, physical activity, and alcohol consumption) were assessed through questionnaires from the baseline to the first follow-up visit. Cox proportional hazard models were used to estimate hazard ratios(HRs) and corresponding 95% confidence intervals(CIs). The risk advancement periods(RAPs: the age difference between exposed and unexposed participants reaching the same incident CVD risk) and population-attributable risk percentage(PAR%) were also calculated.RESULTS A total of 909 incident CVD cases occurred over a median follow-up of 11.14 years. Compared with maintaining 0-1healthy LFs, maintaining 3–4 healthy LFs was associated with a 40% risk reduction of incident CVD(HR = 0.60, 95% CI: 0.45–0.79)and delayed CVD risk by 6.31 years(RAP:-6.31 [-9.92,-2.70] years). The PAR% of maintaining 3–4 unhealthy LFs was 22.0%compared to maintaining 0-1 unhealthy LFs. Besides, compared with maintaining two healthy LFs, improving healthy LFs from 2to 3–4 was associated with a 23% lower risk of CVD(HR = 0.77, 95% CI: 0.60–0.98).CONCLUSIONS Long-term sustenance of healthy lifestyles or improving unhealthy lifestyles can reduce and delay CVD risk.

上海市区慢性肺部疾病史与男性肺癌关系的前瞻性队列研究

目的:研究肺气肿、肺结核、慢性支气管炎和哮喘等慢性肺部疾病史与男性肺癌之间的关系。方法:建立2002—2006年上海市区61500例男性队列调查资料,应用COX回归模型分析肺气肿、肺结核、慢性支气管炎和哮喘等慢性肺部疾病史与男性肺癌发生的风险比(hazard ratio,HR)及其95%可信区间(confidence interval,CI)。结果:截至2008年12月31日,队列中共发生323例肺癌病例。调整了年龄、教育程度、家庭收入、吸烟状态和吸烟包-年等混杂因素后发现,慢性支气管炎可增加男性肺癌的危险性,其HR值为1.87(95%CI:1.35～2.57);进一步调整了体质指数(body mass index,BMI)、能量摄入和体力活动等因素后发现,慢性支气管炎仍可增加男性肺癌发生的危险性,与未患慢性支气管炎者相比差异有统计学意义(P<0.01)。在排除了基线调查前3年内诊断为慢性肺部疾病的对象后发现,慢性支气管炎与肺癌危险性的关联强度没有明显变化。按吸烟史和BMI分层分析发现,在有吸烟史者中,慢性支气管炎增加了肺癌的危险性,其HR为1.58(95%CI:1.14～2.19);在从未吸烟者中,则未发现2者有关联。在非肥胖者(BMI<25)和肥胖者(BMI≥25)中,慢性支气管炎均可使肺癌的发病风险增加。同时各种分析均提示,肺气肿、肺结核和哮喘与肺癌的关联均无统计学意义。结论:慢性支气管炎可能增加了男性肺癌的发病风险。

Sodium butyrate attenuates high-fat diet-induced steatohepatitis in mice by improving gut microbiota and gastrointestinal barrier

AIM To investigate whether gut microbiota metabolite sodium butyrate (NaB) is an effective substance for attenuating non-alcoholic fatty liver disease (NAFLD) and the internal mechanisms. METHODS Male C57BL/6J mice were divided into three groups, normal control were fed standard chow and model group were fed a high-fat diet (HFD) for 16 wk, the intervention group were fed HFD for 16 wk and treated with NaB for 8 wk. Gut microbiota from each group were detected at baseline and at 16 wk, liver histology were evaluated and gastrointestinal barrier indicator such as zonula occluden-1 (ZO-1) were detected by immunohistochemistry and realtime-PCR, further serum or liver endotoxin were determined by ELISA and inflammation-or metabolism-associated genes were quantified by real-time PCR. RESULTS NaB corrected the HFD-induced gut microbiota imbalance in mice, while it considerably elevated the abundances of the beneficial bacteria Christensenellaceae, Blautia and Lactobacillus. These bacteria can produce butyric acid in what seems like a virtuous circle. And butyrate restored HFD induced intestinal mucosa damage, increased the expression of ZO-1 in small intestine, further decreased the levels of gut endotoxin in serum and liver compared with HF group. Endotoxin-associated genes such as TLR4 and Myd88, pro-inflammation genes such as MCP-1, TNF-alpha, IL-1, IL-2, IL-6 and IFN-gamma in liver or epididymal fat were obviously downregulated after NaB intervention. Liver inflammation and fat accumulation were ameliorated, the levels of TG and cholesterol in liver were decreased after NaB intervention, NAS score was significantly decreased, metabolic indices such as FBG and HOMA-IR and liver function indicators ALT and AST were improved compared with HF group. CONCLUSION NaB may restore the dysbiosis of gut microbiota to attenuate steatohepatitis, which is suggested to be a potential gut microbiota modulator and therapeutic substance for NAFLD.

Reference Gene Selection for Normalization of PCR Analysis in Chicken Embryo Fibroblast Infected with H5N1 AIV

Chicken embryo fibroblasts (CEFs) are among the most commonly used cells for the study of interactions between chicken hosts and H5N1 avian influenza virus (AIV).In this study,the expression of eleven housekeeping genes typically used for the normalization of quantitative real-time PCR (QPCR) analysis in mammals were compared in CEFs infected with H5N1 AIV to determine the most reliable reference genes in this system.CEFs cultured from 10-day-old SPF chicken embryos were infected with 100 TCID50 of H5N1 AIV and harvested at 3,12,24 and 30 hours post-infection.The expression levels of the eleven reference genes in infected and uninfected CEFs were determined by real-time PCR.Based on expression stability and expression levels,our data suggest that the ribosomal protein L4 (RPL4) and tyrosine 3-monooxygenase tryptophan 5-monooxygenase activation protein zeta polypeptide (YWHAZ) are the best reference genes to use in the study of host cell response to H5N1 AIV infection.However,for the study of replication levels of H5N1 AIV in CEFs,the β-actin gene (ACTB) and the ribosomal protein L4 (RPL4) gene are the best references.

A novel real-time RT-PCR with TaqM an-MGB probes and its application in detecting BVDV infections in dairy farms

A real-time RT-PCR assay using Taq Man-MGB probes was developed to detect and type the bovine viral diarrhea virus（BVDV） in cattle.Universal primers and Taq Man-MGB probes were designed from the 5′-untranslated region of known pestiviral sequences.Prior to optimizing the assay, c RNAs were transcribed in vitro from the BVDV 1 and BVDV 2 RTPCR products to make standard curves.The detection limit of the assay was 1.72×102 copies for BVDV 1 and 2.14×102copies for BVDV 2.The specificity of the assay evaluated on several BVDV strains including bovine herpesvirus 1（BHV 1）, foot and mouth disease virus（FMDV） and several classical swine fever virus（CSFV） strains showed specific detection of the positive virus over 40 cycles.The assay was highly reproducible with the coefficient of variance ranging from 1.04 to 1.33% for BVDV 1 and from 0.83 to 1.48% for BVDV 2, respectively.Using this method, we tested a total of 2 327 cattle from three dairy farms for the presence of BVDV persistently infected（PI） animals.In this assay, each RT-PCR template contained a mixture of ten samples from different animals.The occurrence rate of PI cattle in three farms ranging from 0.9 to 2.54% could represent partly the PI rates in cattle farm in China.In conclusion, using our real-time PCR assay, we could effectively detect and type BVDV and identify PI cattle in a rapid and cost-effective manner.

Linked PNPLA3 polymorphisms confer susceptibility to nonalcoholic steatohepatitis and decreased viral load in chronic hepatitis B

AIM:To investigate the association of PNPLA3 polymorphisms with concurrent chronic hepatitis B(CHB) and nonalcoholic fatty liver disease(NAFLD).METHODS:A cohort of Han patients with biopsyproven CHB,with or without NAFLD(CHB group,n = 51;CHB + NAFLD group,n = 57),and normal controls(normal group,n = 47) were recruited from Northern(Tianjin),Central(Shanghai),and Southern(Zhangzhou) China.Their PNPLA3 polymorphisms were genotyped by gene sequencing.The association between PNPLA3 polymorphisms and susceptibility to NAFLD,and clinical characteristics of NAFLD were evaluated on the basis of physical indices,liver function tests,glycolipid metabolism,and histopathologic scoring.The association of PNPLA3 polymorphisms and hepatitis B virus(HBV) load was determined by the serum level of HBV DNA.RESULTS:After adjusting for age,sex,and body mass index,we found that four linked single nucleotide polymorphisms(SNPs) of PNPLA3,including the rs738409 G allele(CHB + NAFLD group vs CHB group:odds ratio[OR]= 2.77,95%confidence interval[CI]:1.18-6.54;P = 0.02),rs3747206 T allele(CHB+ NAFLD group vs CHB group:OR = 2.77,95%CI:1.18-6.54;P = 0.02),rs4823173 A allele(CHB +NAFLD group vs CHB group:OR = 2.73,95%CI:1.16-6.44;P= 0.02),and rs2072906 G allele(CHB+ NAFLD group vs CHB group:OR = 3.05,95%CI:1.28-7.26;P = 0.01),conferred high risk to NAFLD in CHB patients.In patients with both CHB and NAFLD,these genotypes of PNPLA3 polymorphisms were associated with increased susceptibility to nonalcoholic steatohepatitis(NASH)(NAFLD activity score ≥3;P =0.01-0.03) and liver fibrosis(>1 Metavir grading;P =0.01-0.04).As compared to those with C/C and C/G at rs738409,C/C and C/T at rs3747206,G/G and G/A at rs4823173,and A/A and A/G at rs2072906,patients in the CHB + NAFLD group with G/G at rs738409,T/T at rs3747206,A/A at rs4823173,and G/G at rs2072906 showed significantly lower serum levels of HBV DNA(P< 0.01-0.05).CONCLUSION:Four linked SNPs of PNPLA3(rs738409,rs3747206,rs4823173,and rs2072906) are correlated with susceptibility to NAFLD,NASH,liver fibrosis,and HBV dynamics in CHB patients.