Summary: Excessive access to fast‐food restaurants (FFRs) in the neighbourhood is thought to be a risk factor for childhood obesity by discouraging healthful dietary behaviours while encouraging the exposure to unhealthful food venues and hence the compensatory intake of unhealthy food option. A literature search was conducted in the PubMed, Web of Science, and Embase for articles published until 1 January 2019 that analysed the association between access to FFRs and weight‐related behaviours and outcomes among children aged younger than 18. Sixteen cohort studies and 71 cross‐sectional studies conducted in 14 countries were identified. While higher FFR access was not associated with weight‐related behaviours (eg, dietary quality score and frequency of food consumption) in most studies, it was commonly associated with more fast‐food consumption. Despite that, insignificant results were observed for all meta‐analyses conducted by different measures of FFR access in the neighbourhood and weight‐related outcomes, although 17 of 39 studies reported positive associations when using overweight/obesity as the outcome. This systematic review and meta‐analysis revealed a rather mixed relationship between FFR access and weight‐related behaviours/outcomes among children and adolescents.

Background: Postpartum depression (PPD) is a common social health problem that affects not only the mother and newborn, but extends to other family members as well as various aspects of their lives. This systematic review and meta–analysis aims to identify the prevalence and risk factors of postpartum among the women in Middle East countries. Methods: We searched published articles from Web of Science, EMBASE, PubMed and Cochrane electronic databases to establish study articles. Articles regarding postpartum depression prevalence and associated factors among women in the Middle East were included in this systematic review and meta–analysis. A random–effect model was used for estimation of pooled postpartum depression prevalence with a 95% confidence interval (CI) and forest plot. Presence of heterogeneity was checked by Cochran's (Q) test, and funnel plots and Egger’s statistical tests were used to assess publication bias. Results: A total of 15 studies were included in this systematic review. The studies were conducted in different countries of the Middle East between 2006 and 2020, nine of the included studies were cross–sectional studies and six were cohort studies. The overall pooled estimate of the prevalence of postpartum depression in the Middle East mothers was very high 27% (95% CI 0.19–0.35). The common risk factors reported based on our review were poor economic, pregnancy associated complications, low education, unplanned pregnancy, housewife, inadequate social support from family members and the feeding by formula. Poor economic and complication during pregnancy presented a significant relationship regarding postpartum depression in meta–analysis. Conclusions: The prevalence of postpartum depression in the Middle East was higher than other regions of the world. In response to this, we recommend an increase of routine screening for depression during postpartum in this area. Furthermore, it might be necessary to integrate mental health with maternal health care in clinical practice during the postpartum.

This study aimed to assess the accuracy of body mass index (BMI) percentile, waist circumference (WC) percentile, waist-height ratio, and waist-hip ratio for identifying cardiometabolic risk factors in Chinese children and adolescents stratified by sex and BMI categories. We measured anthropometric indices, fasting plasma glucose, lipid profile and blood pressure for 15698 participants aged 6–17 in a national survey between September and December 2013. The predictive accuracy of anthropometric indices for cardiometabolic risk factors was examined using receiver operating characteristic (ROC) analyses. The DeLong test and Z test were used for the comparisons of areas under ROC curves (AUCs). The prevalence of impaired fasting glucose, dyslipidemia, hypertension and cluster of risk factors were 2.9%, 27.3%, 10.5% and 5.7% respectively. The four anthropometric indices showed poor to fair discriminatory ability for cardiometabolic risk factors with the AUCs ranging from 0.53–0.72. Each index performed significantly better AUCs for dyslipidemia (0.59–0.63 vs. 0.56–0.59), hypertension (0.62–0.70 vs. 0.55–0.65) and clustered risk factors (0.70–0.73 vs. 0.60–0.64) in boys than that in girls. BMI percentile performed the best accuracy for hypertension in both sexes; WC percentile had the highest AUC for dyslipidemia and BMI percentile and waist-height ratio performed similarly the best AUCs for clustered risk factors in boys while BMI percentile, WC percentile and waist-height ratio performed similar and better AUCs for dyslipidemia and clustered risk factors in girls; whereas waist-hip ratio was consistently the poorest predictor for them regardless of sex. Though the anthropometric indices were more predictive of dyslipidemia, hypertension and clustered risk factors in overweight/obese group compared to their normal BMI peers, the AUCs in overweight/obese group remained in the poor range below 0.70. Anthropometric indices are not effective screening tools for pediatric cardiometabolic risk factors, even in overweight/obese children.

Microcystins (MCs) are the most common and toxic cyanotoxins that are hazardous to human health and ecosystems. Microcystinase is the enzyme in charge of the initial step in the biodegradation of MCs. The characterization, application conditions, and detoxification mechanisms of microcystinase from an indigenous bacterium Sphingopyxis sp. YF1 towards MC-LR were investigated in the current study. The microcystinase gene of strain YF1 was most similar to Sphingomonas sp. USTB-05 and contained a CAAX-family conversed abortive Infection (ABI) domain. The microcystinase was successful obtained and purified by overexpression in Escherichia coli. The highest degradation rate of MC-LR was 1.0 μg/mL/min under the optimal condition of 30 ℃, pH 7, 20 μg/mL MC-LR, and 400 μg/mL microcystinase. The MC-degrading product was identified as linearized MC-LR, which possessed a much lower inhibitory activity against protein phosphatase 2A than MC-LR. Microcystinase interacted with MC-LR via amino acid residues involved in through the formation of conventional Hydrogen Bond, Pi-Pi T-shapes, Van der Waals force, and so on. The optimal MC-degrading condition of pure microcystinase and its detoxification mechanisms against MC-LR were revealed. The toxicity of purified linearized MC-LR was explored for the first time. These findings suggest that pure microcystinase may efficiently detoxify MCs and it is promising in the bioremediation of MC-polluted environments.

Summary: Grocery store is usually considered to be a healthy food outlet as it provides access to a variety of healthy food, such as fruits and vegetables, which may potentially improve overall dietary quality and protect against obesity. However, findings of the association between grocery store and childhood obesity are controversial. This study aimed to systematically review the evidence on the association between access to grocery stores and childhood obesity. A literature search was conducted in the PubMed, Embase, and Web of Science for articles published before January 1, 2019, using the combinations of three groups of keywords separately for grocery store, children and adolescents, and weight‐related behaviours and outcomes. A total of 27 cross‐sectional and eight longitudinal studies were identified. Controversial results existed among 24 studies, which examined the association between the access to grocery stores and weight‐related outcomes. A null association was observed in almost all meta‐analyses conducted by different measures of grocery stores and weight status, except the analysis between presence of grocery stores and overweight, which reached borderline significance. For weight‐related behaviours, mixed findings were reported between grocery stores and dietary behaviours, and no significant associations were found for physical activity. This systematic review and meta‐analysis suggested that access to grocery stores may have a rather small influence on child weight.

Summary: As an important factor for neighbourhood walkability, the speed limit in the neighbourhood may influence children's physical activity (PA) outdoors, especially active transport, and further their weight status. This review aimed to systematically evaluate the association between neighbourhood speed limit and obesity‐related behaviours and outcomes among children and adolescents. PubMed, Embase and Web of Science were systematically searched for relevant studies published from the inception of the database to 1 January 2019. Sixteen studies were included, with 13 cross‐sectional studies and three longitudinal studies. Speed limit was measured as the percentage/number of high‐speed roads, perception of safe driving speed, perception of speeding and use of traffic‐calming tools in the neighbourhood. Eleven studies measured the use of active transport as the outcome of interest, and seven studies measured PA directly. Eleven studies revealed an association between a lower speed limit and increased PA, whereas one study showed a negative association, and three studies reported non‐significant associations. Only one study associated speed limit with weight status, which reported a non‐significant association. This review generally supported a negative association between speed limit and PA among children and adolescents. More studies are needed to examine their causality, as well as the association between speed limit and weight status, in order to increase the impact of this research area on public health policy making.