Documents López-Carrillo, Lizbeth 2 results

"Our objective was to evaluate alterations in sperm chromatin structure in men occupationally exposed to a mixture of organophosphorus pesticides (OP) because these alterations have been proposed to compromise male fertility and offspring development. Chromatin susceptibility to in situ acid-induced denaturation structure was assessed by the sperm chromatin structure assay (SCSA). Urinary levels of alkylphosphates (DAP) were used to assess exposure. Diethylthiophosphate (DETP) was the most frequent OP metabolite found in urine samples indicating that compounds derived from thiophosphoric acid were mainly used. Chromatin structure was altered in most samples. About 75% of semen samples were classified as having poor fertility potential (>30% of Percentage of DNA Fragmentation Index [DFI%]), whereas individuals without OP occupational exposure showed average DFI% values of 9.9%. Most parameters of conventional semen analysis were within normality except for the presence of immature cells (IGC) in which 82% of the samples were above reference values. There were significant direct associations between urinary DETP concentrations and mean DFI and SD-DFI but marginally ( P = 0.079) with DFI%, after adjustment for potential confounders, including IGC. This suggests that OP exposure alters sperm chromatin condensation, which could be reflected in an increased number of cells with greater susceptibility to DNA denaturation. This study showed that human sperm chromatin is a sensitive target to OP exposure and may contribute to adverse reproductive outcomes. Further studies on the relevance of protein phosphorylation as a possible mechanism by which OP alter sperm chromatin are required."

"OBJECTIVE: The study was designed to evaluate the association between socioeconomic level (as measured by maternal education, maternal occupation, and monthly family income) and anencephaly.
METHODS: The authors conducted a case-control study using data from the Epidemiological Surveillance System Register for Neural Tube Defects for three states of the Mexican Republic: Puebla, Guerrero and the State of Mexico. Mothers of 151 cases of infants born with anencephaly and mothers of 151 control infants born during the period March 2000 to February 2001 were interviewed about their socioeconomic characteristics and other factors including reproductive history, use of prenatal care, use of tobacco and alcohol, fever during pregnancy, and folic acid supplementation.
RESULTS: After adjustment for potential confounders, a risk gradient was seen with decreasing maternal education. Women with less than a primary school education (adjusted odds ratio [OR]=3.0; 95% confidence interval [CI] 1.2, 7.6) and women who had completed primary school but had not completed junior high school (adjusted OR=2.2; 95% CI 0.9, 5.7) had higher risks of giving birth to an infant with anencephaly, compared to women with a higher educational level. A monthly income < or = 1,000 pesos (approximately dollars 100 U.S.) was also associated with a higher risk of anencephaly (OR=2.5; 95% CI 1.2, 5.1). Women employed in industry or agriculture during the acute risk period (three months prior to conception to one month after conception) had a risk 6.5 times (95% CI 1.4, 29.6) that of professional and business women.
CONCLUSIONS: This study helps to identify groups that may be especially vulnerable to this type of congenital malformation so that primary and secondary preventive strategies can be targeted to these groups."