Qingying Zhang

Downregulation of placental S100P is associated with cadmium exposure in Guiyu, an e-waste recycling town in China.

Excessive release of heavy metals, especially cadmium (Cd) and lead (Pb), results from primitive electronic waste (e-waste) recycling activities in Guiyu, China, and has adverse effects on the health of local infants and pregnant women. We investigated the expression of placental S100P, a Ca(2+)-binding protein, as a biological indicator of heavy-metal environmental pollution in pregnant women involved in these activities and constantly exposed to Cd and Pb. We included 105 pregnant women in the study: 55 from Guiyu and 50 from Shantou, an area not involved in e-waste recycling. The placental concentrations of Cd and Pb (PCCd, PCPb) after birth were measured by graphite-furnace atomic-absorption spectrometry. S100P mRNA expression was determined by semi-quantitative RT-PCR and real-time quantitative PCR. S100P protein expression was examined by western blot analysis and immunohistochemistry. The expression of metallothionein (MT), previously found upregulated after heavy metal contamination, was used for comparison. Placentas from Guiyu women showed 62.8% higher Cd concentrations, higher MT levels, and lower S100P protein levels than placentas from Shantou women. Furthermore, PCCd was negatively correlated with S100P protein expression and positively with MT expression, with no correlation between PCPb and S100P or MT expression. The PCCd-associated downregulation of S100P in placentas from Guiyu women suggests that S100P might be an effective biological indicator in the placental response to Cd toxicity in areas of e-waste recycling.

Short Placental Telomere was Associated with Cadmium Pollution in an Electronic Waste Recycling Town in China

In Guiyu, an electronic waste recycling site near Shantou, Guangdong province, China, primitive ways of e-waste processing have caused severe cadmium and lead pollution to the local residents. However, the possible effects of cadmium or lead pollution to genomic integrity of the local residents have not been investigated. We examined the possible relationship between cadmium and lead concentrations in placenta and placental telomere length in Guiyu and compared the data with that of a non-polluted town. Graphite furnace atomic absorption spectrometry and real-time PCR were used to determine placental cadmium and lead concentrations, and placental telomere length. We found that placental cadmium concentration was negatively correlated with placental telomere length (r = −0.138, p = 0.013). We also found that placental cadmium concentration of 0.0294 µg/g might be a critical point at which attrition of placental telomere commenced. No significant correlation between placental lead concentration and placental telomere length was detected (r = 0.027, p = 0.639). Our data suggest that exposure to cadmium pollution during pregnancy may be a risk factor for shortened placental telomere length that is known to be related to cancer development and aging. Furthermore, grave consequence on the offspring from pregnancies in e-waste polluted area is indicated.

Status and Significance of CpG Island Methylator Phenotype in Endometrial Cancer

Background: Endometrial cancer is a common gynecologic malignant disease, but patients with advanced disease have a poor prognosis. The CpG island methylator phenotype (CIMP) involves hypermethylation targeted toward the promoters of multiple genes. Objective: To investigate the role of epigenetic aberration of tumor-related genes in endometrial cancer. Methods: The promoter methylation status of 5 genes was examined in 35 endometrial cancer tissues, 15 matched adjacent normal endometrial tissues (NET) from the same cancer patients, and 22 benign endometria from unaffected patients by methylation-specific PCR. CIMP positivity (CIMP+) was defined as concordant methylation of ≧3 genes. Results: The methylation frequency of promoters for the 5 genes in the cancer tissues ranged from 37% for P16 to 57% for P14. Cancer and benign endometria, but not cancer and adjacent NET, significantly differed in methylation of P14, P16, ER, COX-2 and RASSF1A (p < 0.05). CIMP+ was frequent in cancer and adjacent NET (46 and 47%, respectively; p > 0.05), but absent in benign endometria. Moreover, CIMP+ was significantly correlated with methylation of P16 and COX-2 (r = 0.673 and 0.662, respectively; p < 0.001). Conclusion: CIMP+ is an important and frequent epigenetic event in endometrial cancer or adjacent NET, and may be a biomarker for predicting early carcinogenesis. COX-2 is a good representative gene of CIMP+ in this cancer.

Impact of diurnal temperature range on mortality in a high plateau area in southwest China: A time series analysis.

BACKGROUND Diurnal temperature range (DTR) is an important meteorological indicator that reflects weather stability and is associated with global climate change and urbanization. Previous studies have explored the effect of DTR on human health in coastal cities with small daily temperature variations, but we have little evidence for high plateau regions where large DTRs usually occur. Using daily mortality data (2007-2013), we conducted a time-series analysis to assess the effect of DTR on daily mortality in Yuxi, a high plateau city in southwest China. METHODS Poisson regression with distributed lag non-linear model was used to estimate DTR effects on daily mortality, controlling for daily mean temperature, relative humidity, sunshine duration, wind speed, atmospheric pressure, day of the week, and seasonal and long-term trends. RESULTS The cumulative effects of DTR were J-shaped curves for non-accidental, cardiorespiratory and cardiovascular mortality, with a U-shaped curve for respiratory mortality. Risk assessments showed strong monotonic increases in mortality starting at a DTR of approximately 16 °C. The relative risk of non-accidental morality with extreme high DTR at lag 0 and 0-21 days was 1.03 (95% confidence interval: 0.95-1.11) and 1.33 (0.94-1.89), respectively. The risk of mortality with extreme high DTR was greater for males and age <75 years than females and age ≥75 years. CONCLUSIONS The effect of DTR on mortality was non-linear, with high DTR associated with increased mortality. A DTR of 16 °C may be a cut-off point for mortality prognosis and has implications for developing intervention strategies to address high DTR exposure.

Efficacy of Supplementation with B Vitamins for Stroke Prevention: A Network Meta-Analysis of Randomized Controlled Trials

Background Supplementation with B vitamins for stroke prevention has been evaluated over the years, but which combination of B vitamins is optimal for stroke prevention is unclear. We performed a network meta-analysis to assess the impact of different combinations of B vitamins on risk of stroke. Methods A total of 17 trials (86 393 patients) comparing 7 treatment strategies and placebo were included. A network meta-analysis combined all available direct and indirect treatment comparisons to evaluate the efficacy of B vitamin supplementation for all interventions. Results B vitamin supplementation was associated with reduced risk of stroke and cerebral hemorrhage. The risk of stroke was lower with folic acid plus vitamin B6 as compared with folic acid plus vitamin B12 and was lower with folic acid plus vitamin B6 plus vitamin B12 as compared with placebo or folic acid plus vitamin B12. The treatments ranked in order of efficacy for stroke, from higher to lower, were folic acid plus vitamin B6 > folic acid > folic acid plus vitamin B6 plus vitamin B12 > vitamin B6 plus vitamin B12 > niacin > vitamin B6 > placebo > folic acid plus vitamin B12. Conclusions B vitamin supplementation was associated with reduced risk of stroke; different B vitamins and their combined treatments had different efficacy on stroke prevention. Folic acid plus vitamin B6 might be the optimal therapy for stroke prevention. Folic acid and vitamin B6 were both valuable for stroke prevention. The efficacy of vitamin B12 remains to be studied.

Reduced risk of dyslipidaemia with oolong tea consumption: a population-based study in southern China

Experimental studies have suggested that tea consumption could lower the risk of dyslipidaemia. However, epidemiological evidence is limited, especially in southern China, where oolong tea is the most widely consumed beverage. We conducted a population-based case-control study to evaluate the association between consumption of tea, especially oolong tea, and risk of dyslipidaemia in Shantou, southern China, from 2010 to 2011. Information on tea consumption, lifestyle characteristics and food consumption frequency of 1651 patients with newly diagnosed dyslipidaemia and 1390 controls was obtained using a semi-quantitative questionnaire. Anthropometric variables and serum biochemical indices were determined. Drinking more than 600 ml (2 paos) of green, oolong or black tea daily was found to be associated with the lowest odds of dyslipidaemia risk (P< 0.001) when compared with non-consumption, but only oolong tea consumption was found to be associated with low HDL-cholesterol levels. A dose-response relationship between duration of tea consumption and risk of dyslipidaemia (OR 0.10, 95% CI 0.06, 0.16), as well as that between amount of dried tea leaves brewed and risk of dyslipidaemia (OR 0.34, 95% CI 0.24, 0.48), was found. Moreover, consumption of oolong tea for the longest duration was found to be associated with 3.22, 11.99 and 6.69% lower blood total cholesterol, TAG and LDL-cholesterol levels, respectively. In conclusion, the present study indicates that long-term oolong tea consumption may be associated with a lower risk of dyslipidaemia in the population of Shantou in southern China.

Monitoring seasonal influenza epidemics by using internet search data with an ensemble penalized regression model

Seasonal influenza epidemics cause serious public health problems in China. Search queries-based surveillance was recently proposed to complement traditional monitoring approaches of influenza epidemics. However, developing robust techniques of search query selection and enhancing predictability for influenza epidemics remains a challenge. This study aimed to develop a novel ensemble framework to improve penalized regression models for detecting influenza epidemics by using Baidu search engine query data from China. The ensemble framework applied a combination of bootstrap aggregating (bagging) and rank aggregation method to optimize penalized regression models. Different algorithms including lasso, ridge, elastic net and the algorithms in the proposed ensemble framework were compared by using Baidu search engine queries. Most of the selected search terms captured the peaks and troughs of the time series curves of influenza cases. The predictability of the conventional penalized regression models were improved by the proposed ensemble framework. The elastic net regression model outperformed the compared models, with the minimum prediction errors. We established a Baidu search engine queries-based surveillance model for monitoring influenza epidemics, and the proposed model provides a useful tool to support the public health response to influenza and other infectious diseases.

Increased glycemic variability associated with a poor 30-day functional outcome in acute intracerebral hemorrhage

The authors analyzed the association between the standard deviation or the coefficient of variation in the glucose value, strong independent indexes for determining glycemic variability, and the prognosis of intracerebral hemorrhage. They found that glycemic variability may be associated with a poor outcome in intracerebral hemorrhage.

Sleep duration, daytime napping, markers of obstructive sleep apnea and stroke in a population of southern China

Sleep habits are associated with stroke in western populations, but this relation has been rarely investigated in China. Moreover, the differences among stroke subtypes remain unclear. This study aimed to explore the associations of total stroke, including ischemic and hemorrhagic type, with sleep habits of a population in southern China. We performed a case-control study in patients admitted to the hospital with first stroke and community control subjects. A total of 333 patients (n = 223, 67.0%, with ischemic stroke; n = 110, 23.0%, with hemorrhagic stroke) and 547 controls were enrolled in the study. Participants completed a structured questionnaire to identify sleep habits and other stroke risk factors. Least absolute shrinkage and selection operator (Lasso) and multiple logistic regression were performed to identify risk factors of disease. Incidence of stroke, and its subtypes, was significantly associated with snorting/gasping, snoring, sleep duration, and daytime napping. Snorting/gasping was identified as an important risk factor in the Lasso logistic regression model (Lasso’ β = 0.84), and the result was proven to be robust. This study showed the association between stroke and sleep habits in the southern Chinese population and might help in better detecting important sleep-related factors for stroke risk.

Establishment and application of a new diagnostic definition of metabolic syndrome in the Shantou region of southern China

The existing definitions of metabolic syndrome (MetS) may not be fully appropriate for the Shantou population because of ethnic and regional differences. We sought to establish a 95% multivariate medical reference range (MMRR) model for diagnosing MetS in Shantou adults and to evaluate the prevalence of MetS by the MMRR, JCDCG (the Chinese Guidelines), and International Diabetes Federation (IDF) criteria. A total of 4,580 participants were recruited in Shantou, southern China. We developed a MMRR model based on the combinatorial indicatrixes method for three categorized indicatrixes. According to the developed MMRR criteria, men (women) in Shantou have MetS by meeting 3 or more of the following: waist circumference ≥89 (81) cm; triglycerides level ≥1.73 (1.64) mmol/L; high-density lipoprotein cholesterol level ≤1.07 (1.05) mmol/L; blood pressure ≥138/89 (136/85) mmHg; and fasting plasma glucose ≥5.8 (5.7) mmol/L. The agreement of the MMRR with JCDCG and IDF criteria was “substantial” (both κ > 0.68), but the recommended reference values and proportion of individual components of MetS defined by the 3 criteria differed. The population-based MMRR criteria may be appropriate for diagnosing MetS in Shantou population and the model might be useful for generalization to other geographic regions.