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Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants released from the incomplete combustion of fossil fuels and are always found as a mixture of individual compounds. Due to economic growth and a sharp increase in energy consumption in recent years, large quantities of PAHs have been released into the environment worldwide. Because many PAHs and their derivatives are strongly potent carcinogens or mutagens, PAHs have been extensively studied recently. The authors reviewed the origin and distribution of PAHs in atmosphere, soil, and sediment in natural environments. PAHs represent a class of toxicological compounds that can create a variety of hazardous effects in vivo/in vitro, including genotoxicity, immunotoxicity, developmental toxicity, and carcinogenesis, which the authors also describe. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the exposure of neonates to polybrominated diphenyl ethers (PBDEs) from a primitive e-waste (obsolete electrical and electronic devices) recycling area, in Guiyu, China, and a control area, Chaonan, China, through umbilical cord blood (UCB), the health effects, and relevant factors. Questionnaires were addressed, and UCB was collected shortly after birth from 153 pregnant women between May and July 2007. Blood samples were prepared by liquid—liquid extracting methods. PBDE concentration was determined by gas chromatography/mass spectrometry in the electron capture negative ionization mode. The total PBDE concentration was higher in UCB samples from Guiyu than in Chaonan samples (median 13.84, range 1.14-504.97 ng g-1 lipid, vs 5.23, range 0.29-363.70 ng g-1 lipid) (p < 0.05). BDE-209 was the dominant PBDE congener, followed by BDE-47, -153, and -99. Residence in Guiyu, which is a site for e-waste recycling, involvment in e-waste recycling, and the residence also being used as a family workshop were significant factors contributing to PBDE exposure. PBDE levels significantly differed in neonates by normal birth and adverse birth outcomes including stillbirth, low birth weight, and premature delivery (p < 0.05). The neonates from Guiyu are exposed to high levels of PBDEs. Prenatal exposure to PBDEs may affect neonates' health in Guiyu, which still needs to be evaluated in larger epidemiological studies. [ABSTRACT FROM AUTHOR]

Breast cancer is the most prevalent cancer among women in the world, with a notable increasing prevalence in recent decades. Many environmental compounds with estrogenic activity, called environmental estrogens (EEs), which are especially persistent organic pollutants, may play important roles in the occurrence and development of breast cancer and even treatment and prognosis. EE compounds, including bisphenol A, nonylphenol, phthalates, perfluorooctane sulfonate, polybrominated diphenyl ethers, dioxins, and polychlorinated biphenyls, result from industrial manufacturing and exist ubiquitously in the human environment. With the aggravation of environmental pollution, these compounds are residual in all kinds of environmental matrices - especially in industrialized countries. Humans are frequently exposed to them through various pathways, including body contact, inhalation, diet, household products, dust, and cosmetics. They have been detected in many types of human specimens. Their persistence in environmental matrices and humans has aroused global attention because of their effect on public health, especially the occurrence of breast cancer. In this review, we focus on recent research of these seven familiar EEs in industrial pollutants to provide insight into the evidence for risk of breast cancer with exposure to environmental estrogen-like chemicals and to provide clues for prevention and control of breast cancer. [ABSTRACT FROM AUTHOR]

Background & objectives: This study was to survey the apolipoprotein E (APOE) gene polymorphism distribution among Chinese Uyghur children and to explore the relationship between APOE gene polymorphism and the occurrence of urolithiasis. Methods: A total of 144 Uyghur children with urolithiasis and 274 without the history of urolithiasis were enrolled in this study. Venous blood samples were collected from all participants, and APOE genotyping, derived from rs429358 and rs7412, was performed using Sanger sequencing. Results: Among the 418 children, the most prevalent genotype was E3/3, accounting for 71.3 per cent in the urolithiasis group and 71.4 per cent in the control group, followed by E3/4 and E2/3. Higher frequencies of the ɛ2 and ɛ4 alleles and lower frequencies of the ɛ3 allele were observed in the test group, and the unusual allele ɛ1 was also found in them. However, there were no significant differences between cases and controls at both rs429358 and rs7412 genotype and allele frequencies [odds ratio (OR)=0.98, 95% confidence interval (CI): 0.57-1.67; 0.98 (0.59-1.63); 1.43 (0.75-2.74) and 1.40 (0.74-2.62), respectively]. Likewise, none of significant differences was found between cases and controls at both APOE genotype and allele frequencies [OR=0.88, 95% CI: 0.51-1.53; 0.74 (0.33-1.64); 1.10 (0.73-1.66); 1.13 (0.76-1.67) and 1.14 (0.76-1.70), respectively]. Interpretation & conclusions: The present study does not support any association between APOE genotyping and urolithiasis in Uyghur children. [ABSTRACT FROM AUTHOR]

Attention-deficit hyperactivity disorder (ADHD) is a frequent childhood-onset psychiatric condition and categorized into three subtypes of predominantly inattentive (ADHD-I), hyperactive impulsive (ADHD-H), and combined (ADHD-C). The prevalence and subtypes of ADHD vary considerably. The primary aim of this study was to provide a prevalence estimate of ADHD in elementary school students living in Shantou, a district of China, and in addition to examine the influence of informants, age, and gender on the prevalence. A total of 3,497 students aged 7-12 years were enrolled by random and stratified sampling. In stage I, teachers and parents of all participating students in randomly selected schools were asked to complete Chinese versions of the Conners' 10-item scale. In stage II, students with high scores (.15) were interviewed by a psychiatrist for a diagnosis with or without ADHD. Parents rated many more students with high scores than teachers did in stage I. The prevalence of ADHD determined by Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) was 5.91% (5.27%-6.55%), which is comparable to the rates reported in previous studies with Chinese children. This hits the low border of the ADHD prevalence range from 5.9 to 7.1% worldwide, and is lower than that of Chinese children living in Hong Kong, suggesting an important influence of Chinese culture on the diagnosis of ADHD. The constituent ratios of ADHD-I, ADHD-C, and ADHD-H subtypes were 67.43, 24.57, and 8.00%, respectively. The rate of ADHD-H decreased with age, whereas that of ADHD-I remained at the highest levels in all age groups, suggesting that symptoms in the inattention domain are the most persistent and refractory. [ABSTRACT FROM AUTHOR]

Abstract  Divalent metal transporter 1 (DMT1) can transport a large range of ions, including toxic lead (Pb) and cadmium (Cd), across membranes. In this study, a total of 24 rats were divided into four groups for intragastrical perfusion treatment: control, Pb alone, Cd alone, and Pb + Cd. Pb and Cd contents in blood were detected, and the mRNA and protein levels of DMT1 were analyzed in the cerebellum, cortex, and hippocampus. Both Pb and Cd levels were elevated in all groups perfused with Pb and/or Cd, except for Pb level in the Cd-alone group (P P > 0.05). However, the DMT1 protein expression was significantly increased by 0.9-, 1.0-, and 1.1-fold in cerebellum, cortex, and hippocampus of the Pb + Cd group than in controls, respectively. Pb and Cd exposure can synergistically induce DMT1 protein synthesis and has implications for transportation of toxic ions in the developing rat’s brain. [ABSTRACT FROM AUTHOR]

Background: Aberrant promoter methylation is an important mechanism for gene silencing. Aims: To evaluate the promoter methylation status of p300 gene in patients with oesophageal squamous cell carcinoma (OSCC). Methods: The methylation status of p300 promoter was analysed by methylation-specific PCR (MSP) in 50 OSCC tissues and the matching non-cancerous tissues. Oesophageal cancer cell lines (ECa-109 and TE-10) were treated with the demethylation agent 5-aza-2'-deoxycytidine (5-Aza-CdR), and p300 mRNA expression was detected by RT-PCR. Results: p300 methytation was found in 42% (21/50) of the OSCC tissues, but in only 20% (10/50) of the corresponding non-cancerous tissues (p = 0.017). In OSCC samples, 65% of those with deep tumour invasion (adventitia) and 63% samples with metastasis revealed p300 promoter methylation (p<0.05). p300 mRNA expression was observed in 19.0% (4/21) of methylated tumours and 58.6% (17/29) of unmethylated tumours (p = 0.005). In addition, p300 mRNA expression was observed in 40% (4/10) of methylated nonneoplastic tissues and 87.5% (35/40) of unmethylated non-tumours (p = 0.001 ). The demethylation caused by 5-Aza-CdR increased the p300 mRNA expression levels in oesophageal cancer cell lines. Conclusions: p300 transcription silenced by promoter hypermethylation could play a role in the pathogenesis of oesophageal squamous cell carcinoma. [ABSTRACT FROM AUTHOR]