Prenatal exposure to phthalates with preterm birth and gestational age: A systematic review and meta-analysis

Phthalates are non-persistent chemicals used in products of daily necessities. The evidence on the relationship of prenatal phthalates exposure and preterm birth remain uncertain and dimed. We Searched Cochrane, EMBASE, PubMed and Qvid Medline and selected studies according to a priori defined inclusion criteria. A total of 20 relevant studies published before March 31, 2020, were included. The main methods to detect heterogeneity and publication bias of included studies were the Q-statistic and Begg's test. Overall summary estimates indicated positive association of prenatal exposure to di(2-ethylhexyl) phthalate [number of studies (n) = 11, odds ratio (OR) = 1.1; 95% confidence interval (CI): 0.89, 1.4], diethyl phthalate [n = 11, OR = 1.1; 95% CI: 0.92, 1.3], dibutyl phthalate [n = 10, OR = 1.1; 95% CI: 0.77, 1.4], butyl benzyl phthalate [n = 10, OR = 1.0; 95% CI: 0.91, 1.2], diisobutyl phthalate [n = 9, OR = 1.1; 95% CI: 0.92, 1.3], diisononyl phthalate [n = 4, OR = 1.1; 95% CI: 0.85, 1.3], and phthalates were negatively associated with gestational age except di(2-ethylhexyl) phthalate and diisononyl phthalate. Most of them were not statistically significant. Subgroup analysis indicated that the heterogeneity was mainly found in the studies conducted in China and matrix collected at first trimester of pregnancy. Substantial heterogeneity and inconsistency of research methods may lead to inconsistent results of maternal phthalates exposure with preterm birth. We recommend a multicenter cohort study with a consistent approach to unravel the complex associations of prenatal phthalates exposure with birth outcomes.

Exposure to multiple metals and the risk of hypertension in adults: A prospective cohort study in a local area on the Yangtze River, China

BACKGROUND

Exposure to multiple metals is recognized as a common and real scenario in daily life. However, limited prospective studies have assessed associations between multiple metals exposure and hypertension.

METHODS

In total, 2625 adults in a local area on the Yangtze River were investigated at baseline from 2014 to 2015 and followed up in 2019. We measured baseline urine levels of 22 metals and used multivariate logistic analysis and Bayesian kernel machine regression (BKMR) to explore associations between multiple metals exposure and the risk of hypertension.

RESULTS

A total of 385 individuals (29.6%) were diagnosed with hypertension. Five metals (cadmium, copper, magnesium, molybdenum and zinc) were positively associated with hypertension in single-metal models. Cadmium and zinc remained significantly positive associations after adjusting for these five metals, with the odds ratio (OR) in the highest quartiles of 1.49 (95% CI: 1.01, 2.21; p-trend = 0.05) and 1.60 (95% CI: 1.08, 2.38; p-trend = 0.02), respectively. BKMR analysis showed a significant joint effect of multiple metals on hypertension when the concentrations of five metals were at or above their 55th percentile compared with their median values. A potential interaction between cadmium and zinc in increasing the risk of hypertension was observed with the OR_int of 1.41 (95%CI: 1.05, 1.89).

CONCLUSIONS

We identified the joint effect of multiple metals on hypertension and observed a significant interaction between cadmium and zinc. Further cohort studies are needed to clarify the health effects of multiple metals exposure in a larger population.

[Application of Touch DNA in Investigation Practice]

With the continuous development of DNA extraction and testing technology, the DNA left at a crime scene plays a decisive role in the determination of criminal suspects in criminal investigation. But in the meanwhile, the anti-reconnaissance awareness of suspect is growing, which leads to a decrease of evidence left at scene during and after a crime. Therefore, in the process of evidence collection at scene, the finding and extraction of touch biological evidence, and the DNA detection are more and more important. At present, the proportion of touch evidence at the crime scene increases, which plays an increasingly important role in the detection of cases. However, with the characteristics of minute quantities, small size and secrecy, these touch evidence is difficult to be observed. What's more, various forms of pollution at the scene greatly accelerate the degradation rate of trace material, thus, the test and analysis of such material has become the emphasis and difficulty of the forensic evidence identification. This article reviews different kinds, collection and extraction methods of touch DNA, the factors that affect the detection and the problems may meet in the detection for providing an application prospect to the forensic practice.

Zearalenone Altered the Serum Hormones, Morphologic and Apoptotic Measurements of Genital Organs in Post-weaning Gilts

The present study was aimed at investigating the adverse effects of dietary zearalenone (ZEA) (1.1 to 3.2 mg/kg diet) on serum hormones, morphologic and apoptotic measurements of genital organs in post-weaning gilts. A total of twenty gilts (Landrace×Yorkshire×Duroc) weaned at 21 d with an average body weight of 10.36±1.21 kg were used in the study. Gilts were fed a basal diet with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. Results showed that 3.2 mg/kg ZEA challenged gilts decreased (p<0.05) the serum levels of luteinizing hormone, however, serum levels of prolactin in gilts fed the diet containing 2.0 mg/kg ZEA or more were increased (p<0.05) compared to those in the control. Linear effects on all tested serum hormones except progesterone were observed as dietary ZEA levels increased (p<0.05). Gilts fed ZEA-contaminated diet showed increase (p<0.05) in genital organs size, hyperplasia of submucosal smooth muscles in the corpus uteri in a dose-dependent manner. However, the decreased numbers of follicles in the cortex and apoptotic cells in the ovarian were observed in gilts treated with ZEA in a dose-dependent manner. Degeneration and structural abnormalities of genital organs tissues were also observed in the gilts fed diet containing 1.1 mg/kg ZEA or more. Results suggested that dietary ZEA at 1.1 to 3.2 mg/kg can induce endocrine disturbance and damage genital organs in post-weaning gilts.

[Relationship between the postmortem interval and nuclear DNA changes of heart muscular cells in mice]

OBJECTIVE

To study the changes of DNA degradation in cells of rats and its relationship with the postmortem interval.

METHOD

8 parameters of cell nuclear (including the tail length, the head radius, the percentage of head DNA, the percentage of tail DNA, the tail moment, the olive moment, the head area and the tail area) were chosen to study their changes in the procedure of DNA degradation in myocardium cells in 111 rats at different postmortem interval from 0 to 72 h by using single-cell gel electrophoresis (SCGE) technology and fluorescent microscope combined with auto-analysis-image system method.

RESULTS

An evident comet tailing was observed in DNA of myocardium cells after electrophoresis, and their changes in all these 8 parameters of cell nuclear were greatly associated with the extension of postmortem interval, which indicate the degradation rate and degree of DNA in the nuclear has a close relationship with postmortem interval in the periods from 0 to 72 h in rats and significant difference were found with those groups (P < 0.001).

CONCLUSION

The equations, which were concluded from our study, indicate the close relationship of degradation rate and degree of DNA in the nuclear with postmortem interval from 0 to 72 h, and provide an objective and exact new way to estimate the postmortem interval.