Nail Selenium Level and Diabetes in Older People in Rural China.

This cross-sectional study aimed to examine the association between selenium levels and diabetes in an older population with life-long natural exposure to selenium in rural China. A total of 1856 subjects aged 65 years or older from four Chinese rural counties with different environmental selenium levels were evaluated. Analysis of covariance models and logistic regression models were used to examine the relationship between nail selenium levels and serum glucose, serum insulin, insulin resistance [using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)], and the risk of diabetes. The mean nail selenium level was 0.461 µg/g and the prevalence rate of diabetes was 8.3% in this population. The mean nail selenium level was significantly higher in the group with diabetes than in the group without diabetes (P<0.0001). The adjusted odds ratios for diabetes were 2.65 (95% CI: 1.48 to 4.73), 2.47 (95% CI: 1.37 to 4.45), and 3.30 (95% CI: 1.85 to 5.88) from the second selenium quartile to the fourth quartile, respectively, compared with the first quartile group. The mean serum glucose and HOMA-IR in the higher selenium quartile groups were significantly higher than those of the lowest quartile group. However, no significant differences in insulin were observed among the four quartile groups. A long-term, higher level of exposure to selenium may be associated with a higher risk of diabetes. Future studies are needed to elucidate the association between selenium and insulin resistance.

[Gene expression patterns of offsprings' hepatocytes induced by prenatal Benzo[a]pyrene exposure].

OBJECTIVE: To study the gene expression patterns in livers of infant rats after Benzo[a]pyrene (BaP) exposure during pregnancy and explore the important gene and signaling pathways in the toxic mechanism of BaP. METHODS: Thirty-two pregnant SD rats were randomly divided into four groups: vehicle control (corn oil) and treatment groups (0.75, 1.50 and 3.00 mg/kg BaP in corn oil). BaP solutions were given by gastric infusion from the 3rd to the 17th day of pregnancy. After delivery the offspring's liver were taken to detect the gene expression by RatRef-12 gene chip. The stability of gene chip was tested by repeated experiments. RESULTS: After prenatal BaP exposure 1232 genes with different expression variations in hepatocytes of offsprings were identified. Three expression patterns of genes related to the dose of prenatal BaP exposure were identified with significant difference (P < 0.05). As the dose of prenatal BaP exposure increased, the gene expression patterns were downregulated, upregulated, and fluctuated. Twenty-six signaling pathways with differently expressed genes mainly focused on: growth and development, toxicant metabolism and inflammation (P < 0.05). The data from gene network analysis demonstrated that CYP2C13, GSTO1, Rela, MAPK8 and Plcg1 were the key genes in the gene network. CONCLUSION: Gene expression patterns of offsprings' hepatocytes were influenced by prenatal BaP exposure. Some key genes and signal pathways were also found. The study provides an important clue for the toxicity and mechanisms of the prenatal BaP exposure on the growth and development of offspring.

[Studies on the nephrotoxicity of chromium compounds].

The toxicity of chromium in different valent are quite different. Cr (III) is a necessary trace element of human body, but excessive intake of Cr (III) may bring about health lesion. Cr (VI) is generally considered 1,000 times more toxic than Cr (III). Renal damge may happen when people contact or intake excessive chromium compounds. The renal function and the concentration of enzyme and protein may be changed. Kidney necrosis can happen in heavy cases. The metaboly of chromium compounds and its nephrotoxicity were reviewed in this paper.

[Toxic effects and the mechanism of mercury on health].

Mercury is an unnecessary element for human body, and it can exist in several physical and chemical forms in the environment. All forms of mercury have toxic effects in a number of organs, especially in the neural system and kidney. Now, with its extensive use in the industry and life, people pay more attention on the health effects which are caused by mercury. In order to know more about it and to make further study in the future, this review will make a summarize on the toxicity and its mechanism of mercury.

Health safety of main water pipe materials supplied in China market.

OBJECTIVE: To assess the health safety of copper, steel and plastic water pipes by field water quality investigations. METHODS: Four consumers were randomly selected for each type of water pipes. Two consumers of every type of the water pipes had used the water pipes for more than 1 year and the other 2 consumers had used the water pipes for less than 3 months. The terminal volume of tap water in copper and steel water pipes should be not less than 0.1 liter, whereas that in plastic water pipes should be not less than 1 liter. RESULTS: The mean values of the experimental results in the second field water quality investigation of the copper and steel water pipes met the Sanitary Standards for Drinking Water Quality. The items of water sample of the plastic water pipes met the requirements of the Sanitary Standards for Drinking Water Quality. CONCLUSION: Copper, steel, and plastic pipes can be used as drinking water pipes.

[Significance of field epidemiologic study to identification of chronic arsenic poisoning].

Chronic arsenic poisoning has serious and extensive impact on human health, which attracts wide attention worldwide. Bases on vast public survey, this article introduces recent field studies on chronic arsenic poisoning from three aspects: exposure history, clinical symptoms and laboratory evidences, and also explains the meaning of each index to the determination of chronic arsenic poisoning, then bring forward some considerations on further epidemiological studies on chronic arsenic poisoning.