Search PubMed⌕ Search

Biomedical subjects

L D Grant

Publications and source records attributed to L D Grant.

43 records · Page 3Linked to original sources
PubMedDate not supplied

The comparative developmental neurotoxicity of lead in humans and animals.

The effects of lead on neurobehavioral development have been extensively investigated in humans as well as animals. This valuable lode of research findings offers a basis for comparing the developmental neurobehavioral toxicity of lead across species and for assessing the validity of animal models of developmental neurotoxicity. Comparisons of human and animal findings suggest that the greatest qualitative similarities involve relatively complex behavioral processes such as cognition and learning. Quantitative comparisons based on dose-response relationships for these endpoints are difficult to make because the relationships are sometimes nonmonotonic (U-shaped) and because blood lead levels may not be directly comparable between species. However, the lowest levels of exposure at which developmental neurobehavioral effects have been observed are similar: 10-15 micrograms/dl in children, less than 15 micrograms/dl in primates, and less than 20 micrograms/dl in rodents. Although the convergence between animal and human findings for other neurobehavioral endpoints is not as striking, sensory-evoked potentials and communicative processes offer two promising areas for continued investigation and cross-species comparison.

Animals↗
PubMedDate not supplied

Chronic neonatal organotin exposure alters radial-arm maze performance in adult rats.

Long-Evans rats were intubated with 0.3 or 1.0 mg/kg of triethyltin sulfate (TET) or 0.3 mg/kg of trimethyltin hydroxide (TMT) from postnatal day 3-29. 1.0 mg/kg of TMT was given on alternate days beginning on postnatal day 3. Learning and memory were assessed in an automated radial-arm maze when the rats were 180-200 days old. With this maze accuracy and activity data can be collected simultaneously. TET or TMT treatment resulted in an increase in the number of days required to adequately perform and radial-arm maze task, and a transient deficit in accuracy. However, the most pronounced effect in both TET and TMT-treated animals was hyperactivity which became manifest on the second day of testing and persisted throughout the remainder of testing.

Analysis of Variance↗
PubMedDate not supplied

Current issues in human lead exposure and regulation of lead.

Concern about lead as a significant public health problem has increased as epidemiological and experimental evidence has mounted regarding adverse health effects at successively lower levels of lead exposure. This concern has led to downward revision of criteria for acceptable blood lead concentrations to the 10 micrograms/dL mark now designated by EPA as a target level for regulatory development and enforcement/clean-up purposes. Much progress has been made in reducing lead exposures during the past 10-15 years, with marked declines evident both in air lead and blood lead concentrations in parallel to the phase-down of lead in gasoline and notable decreases in food lead exposure due to elimination of lead soldered cans by U.S. food processors. With the lessening of exposure from these sources, the importance of other components of multimedia exposure pathways has grown and stimulated increasing regulatory attention and abatement efforts to reduce health risks associated with lead exposure from drinking water, from lead-based paint, and from household dust and soil contaminated by deteriorating paint, smelter emissions, or various other sources. Increasing attention is also being accorded to reduction of occupational lead exposures (including those related to lead abatement activities), with particular concern for protection of men and women during their reproductive years.

Air Pollutants↗