Nitric oxide and superoxide anion production in monocytes from children exposed to arsenic and lead in region Lagunera, Mexico.

We evaluated in Mexican children environmentally exposed to arsenic and lead monocyte nitric oxide (NO) and superoxide anion production in response to direct activation with interferon-gamma (IFN-gamma) + lipopolysaccharide (LPS). The integrity of Th1-regulated cellular immune response when monocytes were indirectly activated was also evaluated. Most children lived near a primary lead smelter. Lead and arsenic contamination in soil and dust by far exceeded background levels. As levels in water were between 10 and 30 ppb. Most children (93%) had urinary arsenic (AsU) concentrations above 50 microg/l (range 16.75-465.75) and 65% had lead blood levels (PbB) above 10 microg/dl (range 3.47-49.19). Multivariate analyses showed that NO production in monocytes activated indirectly was negatively associated with both PbB and AsU. Superoxide production in directly activated monocytes was negatively associated with AsU but positively associated with PbB. The models including the interaction term for AsU and PbB suggested the possibility of a negative interaction for NO production and a positive interaction for superoxide. There were indications of differential gender-based associations, NO production in indirectly activated monocytes obtained from girls was negatively associated with AsU but not with PbB. Superoxide production was positively associated with PbB in both directly and indirectly activated monocytes from boys but the latter was negatively associated with AsU. These effects are consistent with immune system abnormalities observed in human populations exposed to Pb or As. Further studies in larger populations are required to characterize As and Pb interactions and the mechanism(s) underlying the observed effects.

p53 expression in circulating lymphocytes of non-melanoma skin cancer patients from an arsenic contaminated region in Mexico. A pilot study.

Arsenic is a common environmental toxicant and epidemiological studies associate arsenic exposure with various pathologic disorders and several types of cancer. Skin cancers are the most common arsenic-induced neoplasias and the prevalence of skin lesions has been reported to be significantly elevated in individuals exposed to arsenic via drinking water in Mexico. Being lymphocytes the main cells used for human monitoring, we evaluated the expression of p53 protein in the lymphocytes from 44 healthy individuals and 19 samples from individuals living in a chronic arsenicism endemic region. Of the latter group, 12 individuals had non-melanoma skin cancer and 9 of them expressed p53 in the circulating lymphocytes, whereas only one of the 7 non-cancer arsenic exposed individuals expressed it. In the healthy non-arsenic exposed group only one from 44 individuals expressed the protein. These results suggest a clear relationship between non-melanoma skin cancer and p53 expression in circulating lymphocytes. p53 expression in circulating lymphocytes should be evaluated as a potential biomarker of effect or susceptibility.

[Respiratory function in allergic asthmatic children and its relation to the environmental pollen concentration]. / Función respiratoria en niños asmáticos alérgicos y su relación con la concentración ambiental de polen.

BACKGROUND: Bronchial asthma is the most common chronic disease in children, producing the highest absenteeism among children and adults. OBJECTIVE: To determine the relation between respiratory function in asthmatic children and contaminant and climatic environmental factors. MATERIAL AND METHODS: It was performed a study with 26 asthmatic patients, from the Immuno-Allergies Department of the Specialties Hospital no. 71 of the Centro Medico Nacional Torreon, with an 8-month-follow-up. By a home monitoring, subjects determined their peak expiratory flow (PEF) twice a day: PEF1: in the morning, at getting up without or before medication, and PEF2: at night, before sleeping without or before medication. RESULTS: From June to August 1995, as well as from September to November 1995, a relation between pulmonary function, measured by PEF1 and PEF2, and some of the palinologic families or species studied was not found. On the other hand, from December 1995 to February 1996 a significant relation between the concentration of pollen's particles of Chenopodiaceaes and Amaranthaceaes and the difference between PEF1 and PEF2 (Difpef), with a p value < 0.05. CONCLUSIONS: Environmental Chenopodiaceaes' and Amaranthaceaes' pollen is related to a variability of 0.0075 L/min of Difpef for each grain of pollen/m3 in the environment during winter, after rain time of the Comarca Lagunera.