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Tryptophan (TRP) and its metabolites exhibit significant biological effects and are strongly associated with age‐related disease and mortality. However, reports on quantitatively analyzing these metabolites in older individuals are not available. We used ultra‐high‐performance liquid chromatography–tandem mass spectrometry to optimize and validate a method for isotope dilution analysis of TRP metabolites in older individuals. The targeted analytes are TRP, serotonin or 5‐hydroxytryptamine, kynurenine, kynurenic acid, xanthurenic acid, indole‐3‐acetic acid, indole‐3‐propionic acid, and tryptamine. The serum sample was purified using solid‐phase extraction and was separated on a Waters HSS T3 column (100 mm × 2.1 mm, 1.8 μm). The analytes were detected in the multiple reaction monitoring mode under positive ionization. TRP was confirmed and measured after being diluted 100 times. This method exhibited satisfactory linearity (r > 0.99). The intrabatch and interbatch accuracies (85.7–114%) and precisions (<15%) were acceptable. The standard‐normalized matrix effects ranged from 51.6 to 145%. This method was successfully applied to a cohort of 1021 older Chinese individuals, and this study may enable further understanding of the metabolic phenotypes associated with TRP in other populations. [ABSTRACT FROM AUTHOR]

Problem: 11β‐Hydroxysteroid dehydrogenase 2 (11β‐HSD2) catalyzes active glucocorticoids into their inactive products, preventing the passage of glucocorticoids into the fetus from maternal circulation. Peroxisome proliferator‐activated receptor (PPAR)γ is a member of the nuclear receptor superfamily that regulates the expression of placental 11β‐HSD2. Nuclear factor‐kappa B (NF‐κB) is a transcription factor that regulates inflammatory signaling. This study aimed to investigate the association among 11β‐HSD2, PPAR‐γ, and NF‐κB p65 in small‐for‐gestational‐age (SGA) infants. Method of study: Forty‐six SGA and 46 appropriate‐for‐gestational‐age (AGA) infants were enrolled in this study. Both newborns and placentas were weighed. Placental 11β‐HSD2 levels were measured using Western blotting. Placental PPAR‐γ and NF‐κB p65 were detected by immunohistochemistry. Placental inflammatory cytokines were evaluated by real‐time RT‐PCR. Results: 11β‐HSD2 levels were lower in SGA placentas than those in AGA placentas. Placental PPAR‐γ‐positive nuclei were less in SGA than those in AGA. By contrast, placental NF‐κB p65‐positive nuclei were more in SGA than those in AGA. The levels of CRP, TNF‐α, IL‐8, and IL‐1β, several inflammatory cytokines, were higher in SGA placentas. Correlation analysis showed that neonatal weight was positively associated with PPAR‐γ and 11β‐HSD2 in SGA placentas. By contrast, neonatal weight was inversely correlated with NF‐κB p65 in SGA placentas. 11β‐HSD2 was positively correlated with PPAR‐γ in SGA placentas. Conclusions: Inflammation‐associated downregulation of placental PPAR‐γ and 11β‐HSD2 may be involved in SGA. [ABSTRACT FROM AUTHOR]

Summary: Objective: Hypertensive disorders of pregnancy (HDP) have been associated with adverse health outcomes for both mothers and children. Previous studies examining associations of maternal thyroid autoantibodies with HDP indicate conflicting results. The objective of this study was to examine associations of maternal thyroid autoantibody positivity in the first and the second trimesters with the risk of HDP. Design, Participants and Measurements: In the Ma'anshan Birth Cohort study, a population‐based prospective study in China, a total of 3474 pregnant women were enrolled between May 2013 and September 2014. Thyroid autoantibodies, including antithyroperoxidase autoantibody (TPOAb) and antithyroglobulin autoantibody (TgAb), as well as thyroid function tests, were measured in both the first and the second trimesters in 2893 pregnant women. Multivariate logistic regression analyses were conducted to calculate the odds ratio (OR) and 95% confidence interval (CI) for the associations between thyroid autoantibodies and HDP. Results: Multivariate logistic regression analyses showed that TPOAb positivity in the first trimester was associated with a 1.80 (95% CI = 1.17‐2.78) increased odds of HDP after adjustment for confounders, which was mainly due to an increased risk of gestational hypertension (OR = 1.93, 95% CI = 1.17‐3.18). In addition, TgAb positivity in the first trimester was associated with a higher risk of HDP (OR = 1.78, 95% CI = 1.16‐2.73) after adjustment for confounders, which was mainly due to an increased risk of gestational hypertension (OR = 1.89, 95% CI = 1.15‐3.11). These associations were also seen among euthyroid women. Women with positive TPOAb in the second trimester seemed to have a higher risk of gestational hypertension (OR = 1.87, 95% CI = 1.02‐3.43) after adjustment for confounders. However, among euthyroid women, TPOAb positivity in the second trimester was not associated with HDP. The TgAb status in the second trimester was not associated with HDP. Conclusions: Our results show that TPOAb positivity and TgAb positivity in the first trimester are associated with an increased risk of HDP. These data demonstrate that these associations are even seen among euthyroid women. [ABSTRACT FROM AUTHOR]

Aim We performed a meta-analysis of randomized controlled trials (RCT) and observational studies to answer the two following questions: (i) whether low maternal circulating 25 hydroxyvitamin D (25-OHD) is associated with an increased risk of preterm birth (PTB) or spontaneous PTB (sPTB); and (ii) whether vitamin D supplementation alone during pregnancy can reduce the risk of PTB. Methods Literature search was carried out using Pubmed, Web of Science and Embase databases up to June 2016. Pooled OR or relative risk (RR) with 95%CI were computed using fixed or random effects models depending on the size of heterogeneity. Subgroup analysis was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Egger's test and Begg's test. Results Twenty-four articles (six RCT and 18 observational studies) were identified. Maternal circulating 25-OHD deficiency (pooled OR, 1.25; 95%CI: 1.13-1.38) rather than insufficiency (pooled OR, 1.09; 95%CI: 0.89-1.35) was associated with an increased risk of PTB, and vitamin D supplementation alone during pregnancy could reduce the risk of PTB (pooled RR, 0.57; 95%CI: 0.36-0.91). This was also the case for the sPTB subgroup (circulating 25-OHD <50 vs >50 nmol/L; pooled OR, 1.45; 95%CI: 1.20-1.75). Conclusions Maternal circulating 25-OHD deficiency could increase PTB risk and vitamin D supplementation alone during pregnancy could reduce PTB risk. Extrapolation of the results, however, must be done with caution, and there is urgent need for larger, better-designed RCT to confirm this effect. [ABSTRACT FROM AUTHOR]

Purpose To determine whether elevated light levels in classrooms in rural areas can protect school-age children from myopia onset or myopia progression. Methods A total of 317 subjects from 1713 eligible students aged six to 14 in four schools located in northeast China participated in the study. Students received a comprehensive eye examination including cycloplegic refraction and ocular biometry, which included axial length (AL), anterior chamber depth (ACD), and corneal curvature (CC) measurement, and completed a questionnaire. The intervention arm included 178 students in two schools with rebuilt elevated lighting systems and the control arm included 139 students in which lighting systems were unchanged. Results for the two arms were compared with a Wilcoxon rank sum test, a chi-squared test or a t-test, as appropriate. Factors that might help explain any differences were explored with multivariate linear regression analysis. Results The median average illuminance of blackboards and desks and uniformity of desk lighting were significantly improved, however, the uniformity of blackboard lighting declined after intervention. At baseline, the mean refraction, AL, CC, ACD and myopia prevalence between the two arms were not significantly different. After 1 year, compared with the control arm the intervention arm had a lower incidence of new myopia onset (4% vs 10%; p = 0.029), a smaller decrease in refractive error among no myopic subjects (−0.25 dioptre [D] vs −0.47 D; p = 0.001), and shorter axial growth for both non-myopic (0.13 vs 0.18 mm; p = 0.023) and myopic subjects (0.20 vs 0.27 mm; p = 0.0001). Multivariate linear regression analysis showed the intervention program, lower hyperopic baseline refraction, lower father's education level, longer time sleeping and less time in screen-viewing activities were associated with less refractive shift in the direction of myopia in non-myopic children. For myopic subjects, myopia progression was significantly associated with family income only. The intervention program and older age had a protective effect on axial growth for both myopic and non-myopic subjects. The father's education level and sleep duration were significantly associated with axial growth in non-myopic children. Conclusions Elevated light levels in classrooms have a significant effect on myopia onset, decreases in refraction, and axial growth; if the findings of lighting intervention are reproduced in future studies, the ambient light levels in schools should be improved. [ABSTRACT FROM AUTHOR]

Aim The aim of this study was to assess the cognitive and behavioural development of children with healthy birth outcomes whose mothers were exposed to prenatal stress but did not experience pregnancy complications. Method In this prospective study, self-reported data, including the Prenatal Life Events Checklist about stressful life events ( SLEs) during different stages of pregnancy, were collected at 32 to 34 weeks' gestation. Thirty-eight healthy females (mean age 27y 8mo, SD 2y 4mo) who were exposed to severe SLEs in the first trimester were defined as the exposed infant group, and 114 matched comparison participants were defined as the unexposed infant group (1:3). Maternal postnatal depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale. The Bayley Scales of Infant Development and the Toddler Temperament Scale were used to evaluate the cognitive development and temperament characteristics of the infants with healthy birth outcomes when they were 16 to 18 months old. Results A randomized block multivariate analysis of covariance showed that the mental development index scores of the infants of mothers with prenatal exposure to SLEs in the first trimester averaged seven points (95% confidence interval 3.23-10.73 points) lower than those of the unexposed infants. Moreover, the infants in the exposed group achieved higher scores for regularity (adjusted mean [SD] 2.77 [0.65] vs 2.52 [0.78], F(5,146)=5.27, p=0.023) and for persistence and attention span (adjusted mean 3.61 [0.72] vs 3.35 [0.52], F(5,146)=5.51, p=0.020). Interpretation This study provides evidence that lower cognitive ability and less optimal worse behavioural response in infants might independently result from prenatal maternal stress. [ABSTRACT FROM AUTHOR]

Aim: This investigation aims to evaluate the validity of self-assessment of pubertal Tanner stage in representative Chinese children and adolescents. Methods: The study is a nationally representative cross-sectional survey in eight research sites in the large project entitled 'China Puberty Research Collaboration'. Weight, height, self-assessed pubertal Tanner stage and physical examination of pubic hair in each gender, breast development in girls and genital development in boys from were analysed. Realistic colour images of pubertal rating were used as self-assessment of pubertal stage. Results: A large proportion of subjects aged 7.9-18.9 years old were capable of identifying their own pubertal Tanner stage accurately or close to the rater's assessments. Obese group tends to overestimate their pubertal development compared to non-obese peers, except for genital assessment in boys. The k values for non-obese and obese girls were 0.619 (p < 0.0001) and 0.527 (p < 0.0001), respectively, while the k values for non-obese and obese boys were 0.503 (p < 0.0001) and 0.352 (p < 0.0001). Conclusions: Self-assessment of the pubertal stage by using realistic colour images could be a better alternative assessment tool for large epidemiological puberty research compared with Tanner's original black and white pictures. [ABSTRACT FROM AUTHOR]