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Biomedical subjects

M Maldonado-Vega

Publications and source records attributed to M Maldonado-Vega.

2 recordsLinked to original sources
PubMed1996

Evolution of lead toxicity in a population of children.

A 3 years study was conducted to determine the evolution of blood lead concentrations (PbB) and free erythrocyte protoporphyrins (FEP) as indicators of absorption and biochemical damage in children (7-12 years old) living within one kilometer of a metallurgic factory that processes lead in Torreón, Coahuila, México. In addition, neuromuscular conduction velocity, motor coordination and IQ where determined as indicators of physiological damage. During this period of time the children showed increased lead blood concentrations of 19.2 +/- 4.5 micrograms dl-1 at the beginning of the study to 27.5 +/- 4.9 micrograms dl-1 at the end. Likewise, FEP increased from 56.6 +/- 20.0 micrograms dl-1 to 92.9 +/- 28.9 micrograms dl-1. Physiological damage was evident since motor coefficients as well as IQ tests were reduced significantly when compared to children (7-12 years old) living 4.5 km away from the factory who showed PbB = 8.9 +/- 1.3 micrograms dl-1 and FEP = 16.9 +/- 4.7 micrograms dl-1 throughout the study. Based on these data it was possible to define three different groups with regards to lead toxicity sensitivity.

Adult↗
PubMed1996

Lead: intestinal absorption and bone mobilization during lactation.

The aim of this study was to examine lead (Pb) intestinal absorption, its mobilization and redistribution during lactation in rats chronically exposed to lead. Lead and calcium (Ca) concentrations were measured in blood, milk, femurs, liver and kidney samples obtained from pregnant and lactating mother rats which were subjected to different schedules of exposure to Pb: 158 days before and during lactation (group A), 144 days before lactation (group B) and 14 days only during lactation (group C). Results were compared to those of non-pregnant but Pb-exposed matched rats and non-exposed control rats. In groups A and B during lactation, Pb in blood (PbB), liver and kidney increased while Pb in bone decreased. Since there was not an external source of Pb in group B during lactation, the results indicate resorption of Pb in bone as the main source of Pb in the organism. In group A, there was an additional increase of PbB when compared to group B as a result of Pb intestinal absorption. In group C a significant increase in PbB due to intestinal absorption and deposit in bone was found when compared to non-pregnant 144 days old rats, suggesting that the three processes intestinal absorption, bone resorption and bone absorption were taking place. These data indicate that Pb stored in bone as a result of prior maternal exposure, should be considered as a major source of self intoxication and of Pb in milk available to suckling pups.

Administration, Oral↗