Biomedical subjects

D K Saxena

Publications and source records attributed to D K Saxena.

76 records · Page 5Linked to original sources

PubMedDate not supplied

Blood and placental lead levels in an Indian city: a preliminary report.

A preliminary investigation was carried out in a hospital in the city of Lucknow, India, to provide information on the possible range of lead (Pb) exposure in pregnant women and fetuses, to correlate high Pb levels with various socioenvironmental factors, and to examine any possible association between reproductive outcome and Pb levels in this population. The results indicate that maternal blood lead levels were higher in those who experienced abnormal deliveries and in those who ate nonvegetarian diets or drank groundwater compared with the respective control groups. Placenta, cord blood, and fetal membranes from both normal and abnormal delivery cases showed no significant differences in their Pb content. Other socioenvironmental factors did not influence these Pb levels. However, incidence of higher Pb levels in maternal blood (17% and 38% with Pb > 25 micrograms/dl in normal and abnormal deliveries, respectively) and cord blood (> 10 micrograms/dl) reflect a need for regular monitoring and lowering of environmental Pb exposure.

Adult↗

PubMedDate not supplied

Toxicity of cypermethrin: hsp70 as a biomarker of response in transgenic Drosophila.

Heat shock protein induction is often associated with a cellular response to a harmful environment or to adverse life conditions. The main aims of our study were (1) to evaluate the cytotoxic potential of cypermethrin; and (2) to investigate the suitability of stress-induced heat shock protein Hsp70 as a biomarker for environmental pollutants in transgenic Drosophila melanogaster (Hsp70-lacZ)Bg(9). Different concentrations of cypermethrin (0.002, 0.2, 0.5 and 50.0 p.p.m.) were mixed with food. Third instar larvae of transgenic Drosophila melanogaster were allowed to feed on these mixtures for different time intervals (2, 4, 6, 12, 24 and 48 h). Following feeding, hsp70 induction and tissue damage were evaluated. In the highest concentration treatment group (50 p.p.m.), 100% larval mortality was recorded after 12 h exposure. Hsp70 was found to be induced even at the lowest concentration (0.002 p.p.m.) of the insecticide, while tissue damage was observed in the larvae exposed for 48 h. While an insignificant decline in hsp70 expression was observed in the larvae exposed to cypermethrin at a dietary concentration of 0.002 p.p.m. after 48 h compared with those exposed for 24 h, in the next two higher concentrations of the toxicant, a similar but significant decline in hsp70 expression was evident in the exposed larvae after 48 h. The present study reveals the cytotoxic potential of cypermethrin and further proposes that hsp70 induction in transgenic Drosophila melanogaster could be used as a sensitive biomarker in risk assessment.

Animals↗

PubMedDate not supplied

Effect of low protein diet on manganese neurotoxicity: I. Developmental and biochemical changes.

The first in a series of studies on the effect of concurrent low protein diet (10% casein) and manganese exposure (Mn2+, 3 mg/ml drinking water) in rats is reported here. The effect on growing (Fo-90 days) rehabilitated (Fo low leads to normal protein diet-28 days) and the F1 generation pups (weaned) were studied. Mn2+ exposure had no significant effect on growth pattern, brain weight or brain and plasma protein contents in either dietary groups. The diet regimen had no significant effect on the accumulation of Mn2+ in brain in any of the groups studied but the levels were higher in the F1 pups than in the parent (Fo) generation. In the F1 pups Mn2+ exposure had no effect on eye opening in either dietary group, delayed the development of startle reflex in low protein fed group only but the air righting reflex development was delayed in both the dietary groups, the effect being more marked in the low protein fed group. These changes reflect the early neurotoxic effect of Mn2+.

Animals↗

PubMedDate not supplied

Effect of low protein diet on manganese neurotoxicity: II. Brain GABA and seizure susceptibility.

The effect of manganese (Mn2+, 3 mg/ml drinking water) on brain GABA content and electroshock seizure susceptibility in low (10% casein) and normal (21% casein) protein fed rats were investigated. Manganese exposure caused a decrease in the brain GABA content, lowered the seizure threshold and increased the seizure duration. These effects were more marked in the low protein fed rats. Diet rehabilitation caused a recovery in the GABA levels but has only a moderating effect on the seizure susceptibility and duration. An inverse correlation was observed between the brain GABA levels and seizure threshold. Results indicate a lowered GABA-ergic activity and a functional dysbalance between the GABA-ergic-dopaminergic neuronal systems in manganese toxicity.

Animals↗