Objective Shellfish are recognized as important vehicles of norovirus-associated gastroenteritis. The present study aimed to monitor norovirus contamination in oysters along the farm-to-fork continuum in Guangxi, a major oyster production area in Southwestern China.Methods Oyster samples were collected monthly from farms, markets, and restaurants, from January to December 2016. Norovirus was detected and quantified by one-step reverse transcription-droplet digital polymerase chain reaction (RT-ddPCR).Results A total of 480 oyster samples were collected and tested for norovirus genogroups Ⅰ and Ⅱ. Norovirus was detected in 20.7% of samples, with genogroup Ⅱ predominating. No significant difference was observed in norovirus prevalence among different sampling sites. The norovirus levels varied widely, with a geometric mean of 19, 300 copies/g in digestive glands. Both norovirus prevalence and viral loads showed obvious seasonality, with a strong winter bias.Conclusion This study provides a systematic analysis of norovirus contamination 'from the farm to the fork' in Guangxi. RT-ddPCR can be a useful tool for detection and quantification of low amounts of norovirus in the presence of inhibitors found particularly in foodstuffs. This approach will contribute to the development of strategies for controlling and reducing the risk of human illness resulting from shellfish consumption.
Objective In previous studies, we immunized mice with Ebola recombinant protein vaccine and gene vector vaccine. Both stimulated high levels of humoral immunity. In this work, we constructed a pseudovirus containing Ebola membrane proteins to verify whether the two immunization strategies can induce neutralizing antibodies in mice.Methods A pseudovirus containing an Ebola virus membrane protein based on the HIV-1 viral gene sequence was constructed and evaluated using a known neutralizing antibody. The titer of the neutralizing antibody in the sera of mice immunized with the recombinant protein and the gene vector vaccine was examined using a neutralization test.Results Ebola pseudovirus was successfully prepared and applied for neutralizing antibody detection. Immunological experiments showed that recombinant protein GP-Fc and gene vaccine pVR-modGP-Fc had good immunogenicity. The titer of the bound antibody in the serum after 8 weeks of immunization in mice was more than 1:105, and the recombinant protein induced greater humoral immunity. The results of the neutralization test based on the Ebola pseudovirus system demonstrated that both vaccines induced production of protective antibodies, while the gene vaccine induced a higher titer of neutralizing antibodies.Conclusion An Ebola pseudovirus detection system was successfully established and used to evaluate two Ebola vaccines. Both produced good immunogenicity. The findings lay the foundation for the development of new Ebola vaccines and screening for neutralizing monoclonal antibodies.
Objective To identify the characteristics of Chinese obesogenic environments at a provincial level, infer a spatial distribution map of obesity prevalence in 31 provinces, and provide a foundation for development of policy to reduce obesity in children and adolescents.Methods After scanning obesity data on subjects aged 7-17 years from 12 provinces in the China Health and Nutrition Survey 2011 and environmental data on 31 provinces from the China Statistical Yearbook 2011 and other sources, we selected 12 predictors. We used the 12 surveyed provinces as a training sample to fit an analytical model with partial least squares regression and prioritized the 12 predictors using variable importance in projection. We also fitted a predictive model with Bayesian analysis.Results We identified characteristics of obesogenic environments. We fitted the predictive model with a deviance information criterion of 61.96 and with statistically significant (P < 0.05) parameter estimates of intercept[95% confidence interval (CI):329.10, 963.11], log(oil) (CI:13.11, 20.30), log(GDP) (CI:3.05, 6.93), log(media) (CI:-234.95, -89.61), and log(washing-machine) (CI:0.92, 5.07). The total inferred average obesity prevalence among those aged 7-17 was 9.69% in 31 Chinese provinces in 2011. We also found obvious clustering in occurrences of obesity in northern and eastern provinces in the predicted map.Conclusion Given complexity of obesity in children and adolescents, concerted efforts are needed to reduce consumption of edible oils, increase consumption of vegetables, and strengthen nutrition, health, and physical activity education in Chinese schools. The northern and eastern regions are the key areas requiring intervention.
Objective This study is to examine the influence of familiarity on energy intake, eating behavior, and concentration of the plasma gut hormones in lean and overweight young male subjects.Methods Twenty-eight lean and twenty-eight overweight participants were recruited. Their food consumption was documented and analyzed when they had a test meal while they were paired with friends or strangers at the same weight stature. Their eating behavior was recorded with cameras hidden in the carton, and postprandial plasma gut hormone concentration were measured.Results Compared with overweight strangers (OS), overweight friends (OF) had increased food consumption, prolonged and decreased number of chews per 10 g food. Compared with OS, postprandial plasma concentration of cholecystokinin-8 was significantly lower in OF group at 30, 60, and 90 min, whereas the concentration of glucagon-like peptide 1 was significantly lower at 60 and 90 min. Plasma ghrelin concentration was significantly higher in the OF group than that in the OS group at 90 and 120 min. No significant differences in gut hormone concentration were observed between lean strangers (LS) and lean friends (LF) groups at all time points.Conclusion Familiarity plays an important role in increasing energy intake and in changing of postprandial gut hormone concentration in overweight individuals.
Objective To evaluate the effect of clustering of cardiovascular risk factors (CVRFs) on type 2 diabetes mellitus (T2DM) incidence and identify some high predictive clusters in the Inner Mongolian population in China.Methods A total of 1, 884 Mongolian individuals aged 20 years or above were followed up from 2002 to 2013 and included in the final analysis. We categorized the participants into two subgroups according to the study outcome event. A Cox proportional hazards model was used to evaluate the effect of clustering of CVRFs on the incidence of T2DM. Areas under the curve were used to compare the effect of every cluster on T2DM and identify those having higher predictive value.Results We found 203 persons with T2DM. Subjects with incident T2DM tended to be older, had a higher prevalence of drinking, had higher systolic and diastolic pressures; total cholesterol, triglyceride, low-density lipoprotein cholesterol, and C-reactive protein levels; waist circumference; body mass index; and heart rate and lower HDL-C level than did those without T2DM. The multivariable adjusted hazard ratio (95% confidence interval) of T2DM was calculated based on comparisons with subjects with 0 CVRFs; in participants with 2 and ≥ 3 factors, the adjusted hazard ratios were 2.257 (1.448, 3.518) and 3.316 (2.119, 5.188), respectively.Conclusion The clustering of CVRFs increased the risk of T2DM. On the basis of fast heart rate, the cluster of abdominal obesity and other CVRFs had higher predictive value for T2DM than the other three CVRF clusters.
Objective To discuss the cardiac toxicities of a heat waves and ozone exposure on cardiovascular diseases (CVDs) and explore a possible mechanism.Methods The incidence of ozone exposure combined with heat wave was simulated in the Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS). A total of 64 ApoE-/- mice, matched by weight, were randomly divided into 8 groups and exposed to heat wave conditions or ozone. The levels of creatine kinase (CK), D-lactate dehydrogenase (D-LDH), intercellular adhesion molecule 1 (sICAM-1), tumor necrosis factor alpha (TNF-α), nitric oxide (NO), endothelin-1 (ET-1), D-dimer (D2D), plasminogen activator inhibitor-1 (PAI-1) and blood lipid in plasma and heat shock protein-60 (HSP60), hypoxia inducible factor 1 alpha (HIF-1α), interleukin-6 (IL-6), C-reactive protein (CRP), superoxide dismutase (SOD), and malondialdehyde (MDA) in hearts were measured after exposure.Results The levels of all indicators, except for SOD, increased with the ozone-only exposure. However, cardiac damage was most significant when the heat wave conditions were combined with severe ozone exposure. Moreover, the levels of CK, D-LDH, NO, PAI-1, sICAM-1, and TNF-α in plasma increased significantly (P < 0.05), and the contents of HSP60, HIF-1α, CRP, and MDA in hearts increased considerably (P < 0.05), but the activity of SOD decreased significantly. In addition, the levels of four blood lipid items remarkably increased (except the level of HDL-C which decreased significantly) with ozone exposure.Conclusion A short-term exposure to a heat wave and ozone causes severe toxic effects on the heart. Cardiac damage was most significant under combined heat wave and severe ozone exposure simulations.
To evaluate hormesis induced by Yttrium (Y) nitrate in male rats, Y was offered to F0 mother rats and F1 offspring at concentrations of 0, 20, 80, and 320 ppm daily from gestational day (GD) 0 through postnatal day 70 (PND 70). The F1 offspring were evaluated with respect to motor function, learning and memory, and histopathology. Administration of Y improved motor function in a dose dependent manner. In the 20 ppm group, body weight and spatial learning and memory were increased, while the latter was decreased in the 320 ppm group. Additionally, in the 20 ppm and 80 ppm, but not the 320 ppm groups, Y reduced the anogenital distance, which indicated an anti-androgen effect. These results suggest that Y follows a hormetic concentration-related trend with an inverted U-shape.