Xiaowei Ren

Computational Identification of Antigenicity-Associated Sites in the Hemagglutinin Protein of A/H1N1 Seasonal Influenza Virus.

The antigenic variability of influenza viruses has always made influenza vaccine development challenging. The punctuated nature of antigenic drift of influenza virus suggests that a relatively small number of genetic changes or combinations of genetic changes may drive changes in antigenic phenotype. The present study aimed to identify antigenicity-associated sites in the hemagglutinin protein of A/H1N1 seasonal influenza virus using computational approaches. Random Forest Regression (RFR) and Support Vector Regression based on Recursive Feature Elimination (SVR-RFE) were applied to H1N1 seasonal influenza viruses and used to analyze the associations between amino acid changes in the HA1 polypeptide and antigenic variation based on hemagglutination-inhibition (HI) assay data. Twenty-three and twenty antigenicity-associated sites were identified by RFR and SVR-RFE, respectively, by considering the joint effects of amino acid residues on antigenic drift. Our proposed approaches were further validated with the H3N2 dataset. The prediction models developed in this study can quantitatively predict antigenic differences with high prediction accuracy based only on HA1 sequences. Application of the study results can increase understanding of H1N1 seasonal influenza virus antigenic evolution and accelerate the selection of vaccine strains.

Metabolic syndrome and the risk of breast cancer among postmenopausal women in North-West China.

ABSTRACT Objective To determine whether metabolic syndrome (MetS) and its components are risk factors for breast cancer among postmenopausal women in China. Methods Based on the baseline data of the Jinchang Cohort, a case–control study was carried out among postmenopausal women, including 43 cases and 86 controls. Both MetS and its components were evaluated. Odds ratios and 95% confidence intervals (CI) for the association were estimated by conditional logistic regression analysis. Results The odds ratio of postmenopausal breast cancer was 3.505 (95% CI 1.282–9.583) for MetS, 3.016 (95% CI 1.044–8.715) for body mass index (BMI) ≥ 25 kg/m2, and 3.191 (95% CI 1.253–8.125) for dyslipidemia. There was no significant association between postmenopausal breast cancer and hypertension as well as diabetes. Women with four metabolic factors showed greater risk for postmenopausal breast cancer (ptrend < 0.05). Dyslipidemia and BMI ≥ 25 kg/m2 showed most significant interaction on breast cancer (odds ratio = 11.359; 95% CI 2.663–48.450). With BMI ≥ 25 kg/m2, the interaction of dyslipidemia and other metabolic factors on breast cancer was higher than that without BMI ≥ 25 kg/m2. Conclusion This case–control study suggested that MetS was associated with an elevated risk of breast cancer among postmenopausal women in north-west China. Overweight and dyslipidemia had the strongest adverse effects on postmenopausal breast cancer.

Metal Exposure and Risk of Diabetes and Prediabetes among Chinese Occupational Workers.

OBJECTIVE To study the association between metal exposure and risk of diabetes and prediabetes among Chinese workers exposed to metals. METHODS We used data obtained from the baseline survey of the Jinchang Cohort Study of workers in Jinchang Industry, the largest nickel production company in China. A total of 42,122 workers ⋝20 years of age were included in the study. A standardized, structured questionnaire was used to collect epidemiological information. Physical examinations and laboratory tests were conducted to evaluate the health status of the participants and to measure various biomarkers including blood sugar, lipids, and urinary metal concentrations. Logistic regression was used to study the association between occupational groups categorized according to the measured metal levels (office workers, low-level; mining/production workers, mid-level; and smelting/refining workers, high-level) and risk of diabetes and prediabetes. RESULTS The overall prevalence of diabetes and prediabetes was 7.5% and 16.8%, respectively. The adjusted odds ratios for diabetes among mining/production workers and smelting/refining workers compared to office workers were 1.5 (95% CI: 1.3, 1.7) and 3.8 (95% CI: 3.4, 4.3), respectively. No association was observed between these occupational groups and prediabetes in this study. CONCLUSION Occupations associated with higher levels of metal exposure were associated with an increased risk of diabetes in this cohort. More studies are needed to confirm this observed association.

Prevalence of Metabolic Syndrome in Chinese Nickel-exposed Workers

The prevalence of metabolic syndrome (MS) was investigated in Chinese nickel-exposed workers. A total of 35 104 subjects were enrolled in this study. The age-adjusted prevalence of MS, BMI⋝25, diabetes, hypertension, and abnormal lipid was 13.9%, 29.5%, 12.8%, 27.5%, and 47.1%, respectively. The prevalence of BMI⋝25, hyperglycemia, and hypertension increased with the age of males and females, and was higher in males than in females (37.1% vs 21.5%, 15.9% vs 12.1%, 35.0% vs 24.3%, 54.3% vs 40.4%).

Reproductive factors and risk of type 2 diabetes in an occupational cohort of Chinese women

AIMS Hormonal milieu has long been known to play an important role in the development of type 2 diabetes (T2D). The aims of this study are to investigate the roles of menstrual and reproductive factors in relation to T2D risk in an occupational cohort of Chinese women; and to explore the role of endogenous estrogen in T2D development. METHODS We conducted a cross-sectional analysis of baseline data from 16114 women (11051 premenopausal and 5063 postmenopausal) aged ≥20years who participated in the ongoing prospective occupational cohort study. Multivariable logistic regressions were modeled to evaluate the associations of reproductive factors with T2D risk. RESULTS Early menarche at age (≤12 versus 15-16 years) was associated with increased T2D risk (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.16-2.22). After multiple adjustment including age, BMI and occupation, postmenopausal status was positively associated with T2D risk (OR: 1.54, 95% CI: 1.10-2.14). Reproductive life span was significantly associated with T2D risk (P=0.02), albeit displaying a U-shape relationship. Similarly, age at menopause was also associated with T2D risk in the same U-shaped as with reproductive life span (P=0.03). Further, years since menopause (P=0.003), but not history of cycle regularity and hormone use, was associated with increased T2D risk. CONCLUSION Reproductive factors were associated with T2D supporting the notion that either a short or prolonged exposure to endogenous estrogen affects T2D risk in Chinese women. Reproductive factors should be added to risk stratification when counseling women about their risk of developing diabetes.

Multiple metals exposure, elevated blood glucose and dysglycemia among Chinese occupational workers

AIMS Exposure to metals may adversely affect cardiometabolic health. The aim of this study is to directly evaluate the roles of multiple metals exposure in glucose homeostasis, the dysfunction of which has been linked to diabetes and cardiovascular diseases (CVDs). METHODS We performed a cross-sectional analysis of baseline data from 464 metal-exposed workers who participated in a large prospective occupational study in China (Jinchang Cohort). The logistic regression model was used to evaluate the association between urinary metal levels and high fasting plasma glucose (high-FPG) (≥ 75th percentile) and dysglycemia. RESULTS Increasing levels of urinary nickel were prospectively associated with high-FPG: multivariable odds ratios (ORs) were 1.00 for the 1st quartile (lowest), 1.20 (95% confidence interval [CI]: 0.60-2.43) for the 2nd quartile, 1.64 (0.78-3.49) for the 3rd quartile and 3.17 (1.38-7.30) for the 4th quartile (highest) (P-trend=0.004). The positive associations were also observed between urinary zinc and high-FPG (4th vs. 1st quartile=2.71, 95%CI: 1.26-5.84, P-trend=0.01). Inverse associations between urinary cobalt and risk of high-FPG and dysglycemia were observed (P-trend <0.05). For dysglycemia, the positive trends of increasing levels of urinary nickel and zinc still remained, although urinary nickel was no longer statistically significant. A significant association between urinary arsenic and dysglycemia was also found. However, no associations were observed between urinary copper, cadmium, and risk of high-FPG or dysglycemia. CONCLUSION Multiple urinary metals, particularly arsenic, nickel, zinc, and cobalt, were associated with elevated blood glucose among Chinese occupational workers, supporting the notion that metal exposure plays a critical role in the development of diabetes.

Etiological epidemiology of viral diarrhea on the basis of sentinel surveillance in children younger than 5 years in Gansu, northwest China, 2009–2013

To explore the etiological spectrum of diarrhea and its epidemiological characteristics in diarrhea symptoms surveillance cases younger than 5 years from 2009 to 2013 in Gansu province, northwest China. Systematic diarrhea symptoms surveillance were conducted in 27 sentinel sites in Gansu province and outpatients with three or more loose, watery, or sticky pus stools per day were defined as surveillance cases. All stool specimens were tested for Rotavirus, Human calicivirus, Adenovirus, and Astrovirus. Totally, 1,119 cases (51.54%) were identified as any enteric virus. The average isolation rate of Rotavirus was 51.13%, Astrovirus was 10.84%, Adenovirus was 6.94%, and Human calicivirus was 6.60% (P < 0.01). Rotavirus was identified with the highest frequency among these enteric pathogens except in 2011, with a notable downward trend over time (P < 0.01). Rotavirus A was the most proportion in rotavirus, G3P[8] and G9P[8] were the most common combination. Rotavirus mixed Human calicivirus infections was the most common mixed infected patterns. Viral‐positive rate was higher among children aged group of 0–12 and 13–24 months (P < 0.01, respectively). The isolation rates of four enteric viral pathogens showed a similar distinct seasonal variation with a higher rate in spring, autumn, and winter months. Rotavirus was the major epidemiological viral pathogen in diarrhea symptom surveillance cases in Gansu province, northwest China, during period 2009–2013. Seasonal and age‐related variations were observed in enteric viral pathogen isolation rate. The comprehensive and continuous surveillance is needed to identify the prevalence of different enteric viral pathogens. J. Med. Virol. 87:2048–2053, 2015.

Sulfur dioxide exposure and other factors affecting age at natural menopause in the Jinchuan cohort

Abstract Objective To describe the associations between occupational exposures and age at natural menopause in the Jinchuan cohort. Methods The Jinchuan cohort consists of all current or retired workers of the Jinchuan Nonferrous Metals Corporation (JNMC) in Jinchang, Gansu, China. Our final study population consisted of 3167 postmenopausal women. The data used for this study were derived from the epidemiological survey and were self-reported. Age at natural menopause (ANM) was defined as the age at the last period prior to 12 months of amenorrhea in women who experienced natural menopause. ANM was related to five commonly reported occupational exposures using bivariate and multivariate Cox proportional hazards regressions. Results Blue-collar workers have significantly earlier mean ANM (49.0 years) than white-collar workers (49.5 years). Sulfur dioxide exposure was found to be associated with earlier mean ANM in blue-collar workers. After stratifying both blue-collar workers and white-collar workers further by exposure time for each of the exposures, blue-collar workers exposed to sulfur dioxide for 21–25 years had the earliest mean ANM (47.8 years) of any level of any exposure in this study. Conclusion This paper is significant because it is the first report of an association between sulfur dioxide and menopause, and one of few papers to look at the determinants of ANM in an occupational cohort. Blue-collar workers had earlier mean ANM than white-collar workers. Blue-collar workers are more exposed to sulfur dioxide and other occupational exposures than white-collar workers, and blue-collar workers who are more exposed to sulfur dioxide have earlier menopause. Sulfur dioxide may be part of the reason that blue-collar workers experience earlier menopause than white-collar workers.

Association between Short-Term Exposure to Air Pollution and Dyslipidemias among Type 2 Diabetic Patients in Northwest China: A Population-Based Study

Air pollution exposure may play an adverse role in diabetes. However, little data are available directly evaluating the effects of air pollution exposure in blood lipids of which dysfunction has been linked to diabetes or its complications. We aimed to evaluate the association between air pollution and lipids level among type 2 diabetic patients in Northwest China. We performed a population-based study of 3912 type 2 diabetes patients in an ongoing cohort study in China. Both spline and multiple linear regressions analysis were used to examine the association between short-term exposure to PM10, SO2, NO2 and total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). By spline analyses, we observed that the relationship between SO2 and HDL-C and LDL-C was shown to be non-linear (p_non-lin-association = 0.0162 and 0.000). An inverted U-shaped non-linear relationship between NO2 and LDL-C was found (p_non-lin-association < 0.0001). A J-shaped non-linear relationship between PM10 and TC, HDL-C (p_non-lin-association = 0.0173, 0.0367) was also revealed. In linear regression analyses, a 10 μg/m3 increment in SO2 was associated with 1.31% (95% CI: 0.40–2.12%), 3.52% (95% CI: 1.07–6.03%) and 7.53% (95% CI: 5.98–9.09%) increase in TC, TG and LDL-C, respectively. A 10 μg/m3 increment in PM10 was associated with 0.45% (95% CI: 0.08–0.82%), 0.29% (95% CI: 0.10–0.49%) and 0.83% (95% CI: 0.21–1.45%) increase in TC, HDL-C and LDL-C, respectively. For NO2, an increment of 10 μg/m3 was statistically associated with −3.55% (95% CI: −6.40–0.61%) and 39.01% (95% CI: 31.43–47.03%) increase in HDL-C and LDL-C. The adverse effects of air pollutants on lipid levels were greater in female and elder people. Further, we found SO2 and NO2 played a more evident role in lipid levels in warm season, while PM10 appeared stronger in cold season. The findings suggest that exposure to air pollution has adverse effects on lipid levels among type 2 diabetes patients, and vulnerable people may pay more attention on severe air pollution days.

Cancer burden in the Jinchang cohort

OBJECTIVE To understand the disease burden caused by cancers in Jinchang cohort, and develop effective strategies for cancer prevention and control in this population. METHODS The cancer mortality data from 2001 to 2013 and the medical records for cancer patients from 2001 to 2010 in Jinchang cohort were collected. The disease burden caused by cancer was analyzed by using mortality rate, potential years of life lost (PYLL), working PYLL (WPYLL), and direct economic burden. RESULTS During 2001-2013, in Jinchang cohort, the five leading cancers ranked by mortality rate were lung cancer (78.06/100,000), gastric cancer (38.03/100,000), liver cancer (37.23/100,000), esophageal cancer (19.06/100,000), and colorectal cancer (9.53/100,000). The five leading cancers in terms of PYLL (person-years) and WPYLL (person-years) were lung cancer (3480.33, 1161.00), liver cancer (2809.03, 1475.00), gastric cancer (2120.54, 844.00), esophageal cancer (949.61, 315.00), and colorectal cancer (539.90, 246.00). From 2001 to 2010, the five leading cancers in term of average daily cost of hospitalization were gastric cancer (8,102.23 Yuan), esophageal cancer (7135.79 Yuan), colorectal cancer (7064.38 Yuan), breast cancer (6723.53 Yuan), and lung cancer (6309.39 Yuan). CONCLUSIONS The cancers common causing higher disease burden in Jinchang cohort were lung cancer, gastric cancer, liver cancer, esophageal cancer and colorectal cancer. The lung cancer disease burden was the highest.