Search PubMed⌕ Search

Biomedical subjects

T J Haley

Publications and source records attributed to T J Haley.

71 records · Page 4Linked to original sources
PubMedDate not supplied

Estimation of the LD1 and extrapolation of the LD0.1 for five organothiophosphate pesticides.

The oral LD50's for five organothiophosphate pesticides have been determined in CD-1 strain male and female mice. The values in mg/kg are: parathion, 15.0 and 14.3; methyl parathion, 14.5 and 19.5; guthion, 7.15 and 6.35; imidan, 25.2 and 23.1; sumithion, 1,045 and 1,220 respectively. Toxicity was greater parathion but there was no difference in the males. The relationship between chemical structure and toxicity has been discussed. The addition of a methyl group in the meta position of the nitrophenyl group (sumithion) decreased toxicity 72 times compared to methyl parathion. The predicted LD1 and extrapolated LD0.1's have been determined for the five organothiophosphates and the conditions required for accurate results have been established. It has been shown that the slopes of the curves (males vs. females) obtained with 50, 100 and 660 animals are parallel for all compounds health implications of exposure to low levels of environmental pesticides have been discussed.

Animals↗
PubMedDate not supplied

A review of the literature of rotenone, 1,2,12,12a-tetrahydro-8,9-dimethoxy-2-(1-methylethenyl)-1-benzopyrano[3,5-b]furo[2,3-h][1]benzopyran-6(6h)-one.

The chemistry, biotransformation, pharmacology, toxicology, and carcinogenicity of rotenone have been reviewed. Further investigation of the biotransformation pathways of rotenone and other rotenoids should be undertaken. The acute and chronic toxicology, particularly at low concentration, should be determined in order to develop toxicity rating for this class of chemicals. A mutagenic study utilizing all presently available methods would add further knowledge concerning sites of action. More information is required to properly evaluate the hazards to humans from rotenone and other rotenoids. Carcinogenic studies at low concentrations with large groups of rodents must be undertaken to settle the present dilemma of carcinogenicity vs. non-carcinogenicity. Moreover, an epidemiological study of exposed workers might develop information concerning the toxicology of rotenone as well as its possible carcinogenicity to humans.

Animals↗
PubMedDate not supplied

An unbalanced experimental design for dose response studies.

Sixty sets of real data for 15 different pesticides from both sexes of Balb/C mice in two different experimental designs were generated at NCTR. The quantal responses for the dose groups in this data ranged from 1% to 90%. It was shown that the data could be represented equally well by a probit or logit transformation. It was further shown that the investment in terms of 7 times as many animals would greatly increase the confidence in estimating the parameters of the model and in predicting the dose at the low end of the dose response. Most important, it was shown that the estimation of a safe dose for a specified risk was greatly influenced by the choice of experimental design and method of extrapolation. It might be worth the investment in better experimental design to both the consumer and to the chemical industry if higher safe doses could be established which would allow the chemical to better accomplish its purpose and yet improve the assurance of the safety of the consumer.

Animals↗