Publications (2)3.66 Total impact
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Article: Effects of lead exposure on sperm concentrations and testes weight in male rats: a meta-regression analysis.
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ABSTRACT: The correlation between exposure to lead (PB) and sperm concentrations and testes weight are important in risk assessment of metal toxicity to male reproductive functions. The authors carried out two systematic reviews and meta-analyses of rats. In addition, a meta-regression analysis was taken to explore a dose-response relationship between the mean difference of testes weight (MD(testes)) and available confounding factors. Data were obtained from computerized literature searches of several databases from their inception through December 2005. The reference lists of identified articles were examined further for relevant articles. The authors identified 6 and 12 studies, separated into 16 and 28 subgroups, in the two meta-analyses. The authors conducted random- or fixed-effect models toward the effect size. Heterogeneity between study results was explored through chi-square tests and meta-regression. Results showed that a decrease in sperm concentrations was found as low as mean difference of sperm concentrations (MD(sperm)) = 30.9 and 95%CI = (25.43-36.37) in a fixed-effect model or MD(sperm) = 35.47 and 95%CI = (15.27-55.68) in a random-effect model after Pb exposure. Similarly, a significantly lower testes weight was also evident: MD(testes) = 0.033 and 95%CI = (0.021-0.046) in a fixed-effect model or MD(testes) = 0.047 and 95%CI = (0.0044-0.089) in a random-effect model. In the meta-regression analysis, two confounders, age and body weight, explained part of the observed heterogeneity. The body weight after Pb exposure was inversely associated with MD(testes). These findings support the notion that Pb exposure produced decreased sperm concentrations and testes weight in rats.Journal of Toxicology and Environmental Health Part A 02/2008; 71(7):454-63. · 1.83 Impact Factor -
Article: Association between delta-aminolevulinic acid dehydratase (ALAD) polymorphism and blood lead levels: a meta-regression analysis.
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ABSTRACT: A meta-regression analysis was undertaken to evaluate the association between delta-aminolevulinic acid dehydratase (ALAD) genotypes and blood lead levels obtained from data published in various journals. In total, 15 studies were included in the final analysis. Both fixed effects and random effects models were used to undertake the pooled analysis. Using a fixed effects model, pooled estimates of mean differences of various ALAD genotypes was significant at 0.61 microg/dl. Using a random effects model, the pooled estimate was also significant at 1.51 microg/dl. Data indicated that certain ALAD genotypes may affect the susceptibility of humans to lead.Journal of Toxicology and Environmental Health Part A 01/2008; 70(23):1986-94. · 1.83 Impact Factor
