Associations between plasma metal mixture exposure and risk of hypertension: A cross-sectional study among adults in Shenzhen, China.

Background: Metal exposure affects human health. Current studies mainly focus on the individual health effect of metal exposure on hypertension (HTN), and the results remain controversial. Moreover, the studies assessing overall effect of metal mixtures on hypertension risk are limited.

Increased emergency cases for out-of-hospital cardiac arrest due to cold spells in Shenzhen, China.

Cold spells have been associated with specific diseases. However, there is insufficient scientific evidence on the effects of cold spells on out-of-hospital cardiac arrest (OHCA). Data on OHCA cases and on meteorological factors and air pollutants were collected between 2013 and 2020.

Exosomal secretion may be a self-protective mechanism of its source cells under environmental stress: A study on human bronchial epithelial cells treated with hydroquinone.

Accumulating evidence reveals that exosome plays an important role in cell-to-cell communication in both physiological and pathological processes by transferring bioactive molecules. However, the role of exosomal secretion in the adaption of its source cells to the stimuli of environmental chemicals remains elusive. In this study, we revealed that the exposure of hydroquinone (HQ; the main bioactive metabolite of benzene) to human bronchial epithelial cells (16HBE) resulted in decreased ability of cell proliferation and migration, and simultaneously DNA damage and micronuclei formation.

Exosomal miR-221 derived from hydroquinone-transformed malignant human bronchial epithelial cells is involved in cell viability of recipient cells.

miR-221, an oncogenic microRNA, can promote cell proliferation and is highly expressed in various types of tumors. However, the role of exosomal miR-221 in benzene-caused carcinogenesis remains elusive. Our study was designed to investigate whether exosomes secreted by the hydroquinone (HQ; an active metabolite of benzene)-transformed malignant cells can transmit miR-221 to normal recipient cells and its possible effects on cell viability.

The relationship between extreme temperature and emergency incidences: a time series analysis in Shenzhen, China.

Extreme temperature has been reported to be associated with an increase in acute disease incidence in several cities. However, few similar studies were carried out in Shenzhen, which is a subtropical city located in the southern China. This study explored the relationship between the emergency incidences and extreme temperatures, and investigated the role of air pollutants played in the temperature-related effects on human health in Shenzhen.

Effect on metabolic enzymes and thyroid receptors induced by BDE-47 by activation the pregnane X receptor in HepG2, a human hepatoma cell line.

2,2',4,4'-Tetra-bromodiphenyl ether (BDE-47), an important congener among polybrominated diphenyl ether (PBDE) compounds, has been predominantly in environmental samples and human tissue. Thyroid disruption is the most sensitive endpoint effect among a number of health effects of exposure to BDE-47 in animals and humans. However, the detailed underlying mechanisms in humans are not well understood.

Levels and profiles of PCDD/Fs, PCBs in mothers' milk in Shenzhen of China: estimation of breast-fed infants' intakes.

Sixty breast milk samples were collected in Shenzhen, China from July to November in 2007. The samples were analyzed of the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). The range of upper-bound for ∑TEQ-(PCDD/Fs+PCBs) in the samples was 4.

[Screening and identification of differential serum proteins related to dermatitis medicamentosa-like of trichloroethylene].

Objective: To screen and identify differential serum proteins which might be involved in dermatitis medicamentosa-like of trichloroethylene (DMLT).

Methods: Three groups of sera were collected from population exposed to trichloroethylene (TCE) (group I), patients suffering from DMLT (group II), and the healed cases (group III). After removing albumin and IgG in the three pools of sera, a comparative proteomic analysis was carried out.

[Effects of 2,2',4,4'-tetrabrominated diphenyl ethers on the TRalpha1 and TRbeta1 expression in liver in C57BL/6 mice].

Objective: To study the effect of 2,2',4,4'-tetrabrominated diphenyl ethers (BDE-47) on the expression change of TRalpha1, TRbeta1 at both mRNA and protein levels.

Methods: C57BL/6 mice were divided randomly into 4 groups and administrated with corn oil, 0.5, 5 and 50 mg/kg/BW BDE-47 for 4 days through intraperitoneal injection respectively.

[Study on skin sensitization as well as liver and kidney impairment in guinea pigs treated with trichloroethylene].

Objective: To study skin sensitization as well as liver and kidney impairment in guinea pigs treated with trichloroethylene (TCE).

Methods: Guinea pig maximization test (GPMT) was applied in this study, guinea pigs were divided into 3 groups, namely negative control, positive control and TCE treatment. Animals of 3 groups were administrated with olive oil, 2, 4-dinitrochlorobenzene (DNCB), and TCE, respectively, by intradermal injection.

Elevated body burdens of PBDEs, dioxins, and PCBs on thyroid hormone homeostasis at an electronic waste recycling site in China.

A cross-sectional study of 25 sample sets (each set consisted of maternal serum and cord whole blood) from 50 pregnant women in zone A (n = 25 from exposed group) and zone B (n = 25 from reference group) was conducted to examine the association between thyroid hormone (TH) levels and PBDE, PCDD/F, and PCB exposures. Thyroid hormones TT3, TT4, and TSH levels were measured in maternal serum at 16 weeks of gestation. The concentrations of PBDEs, PCDD/Fs, and PCBs were determined by isotope dilution HRGC/HRMS in cord blood samples.

[Effects and toxicity mechanism of 2,2',4,4'-tetrabrominated diphenyl ethers on the homeostasis of thyroid hormone system in C57BL/6 mice].

Objective: To investigate the effects and of toxicity mechanism of 2,2',4,4'-TETRABDE (BDE-47) on TT3, TT4 and TSH in C57BL/6 mice.

Methods: C57BL/6 mice were divided randomly into 4 groups, and given with corn oil (control group) and 1 micromol/(kg x d), 10 micromol/(kg x day) and 100 micromol/(kg x day) BDE-47 for 4 days through intraperitoneal injection respectively. After collecting the bloods, livers and thyroids, the T3, T4 and TSH levels of serum were detected by electro chemiluminescenc (ECLI), thyroid peroxidase (TPO) activities in thyroid by guaiacol method and type-I deiodinase (DI) in liver by CHOPRA method.

[Levels of PCDD/Fs, PCBs and PBDEs compounds in human placenta tissue].

Objective: To establish the methods of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) compounds determination by isotope dilution HRGC/HRMS simultaneously in human placenta tissue from mothers, and assess the human exposure risk to dioxins and PBDEs in study.

Methods: Concentrations of 17 PCDD/Fs and 12 dioxin-like PCBs as well as 7 PBDEs were measured in human placenta tissue samples by isotope dilution HRGC/HRMS. SigmaTEQ (PCDD + PCDFs + PCBs) concentration using WHO-TEF factor and PBDEs concentration was calculated respectively.

Concentrations of PCDD/PCDFs and PCBs in retail foods and an assessment of dietary intake for local population of Shenzhen in China.

Objectives: Concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 18 polychlorinated biphenyls (PCBs) were measured in 11 varieties of food groups collected from retail market of Shenzhen, Guangdong province, China from 2004 to 2006. PCDD/Fs and PCBs dietary intake from varies food for the local population was estimated in the study.

Methods: Concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (PCBs) as well as 6 marker PCBs were measured in 11 varieties of food groups in total 110 food samples by isotope dilution HRGC/HRMS.

Possible role of DNA polymerase beta in protecting human bronchial epithelial cells against cytotoxicity of hydroquinone.

Objective: To explore the toxicological mechanism of hydroquinone in human bronchial epithelial cells and to investigate whether DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.

Methods: DNA polymerase beta knock-down cell line was established via RNA interference as an experimental group. Normal human bronchial epithelial cells and cells transfected with the empty vector of pEGFP-C1 were used as controls.

[Construction of "pEGFP-C1-pU6-dsRNA" recombinant for human DNA polymerase beta RNA interference].

Objective: To clone the "pEGFP-C1-pU6-dsRNA" recombinant for human DNA polymerase beta RNA interference, to provide research tool for the study on the function of DNA polymerase beta in repairing of human DNA damaged by environmental chemical pollutants (ECPs).

Methods: According to the gene sequence of polymerase beta cDNA published in Genbank, double strand RNA(dsRNA) sequence which was used in RNA interference was designed by dsRNA oligonucleotide designer and synthesized by chemical methods. DNA recombination technology was used to insert the up related dsRNA sequence into the vector of pSIREN-RetroQ, and then the "pSIREN-RetroQ-dsRNA" recombinant was obtained.