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Biomedical subjects

B D Hardin

Publications and source records attributed to B D Hardin.

22 records · Page 2Linked to original sources
PubMed1982

Teratogenicity of 2-ethoxyethanol by dermal application.

Undiluted 2-ethoxyethanol or water (control) was applied to the skin of pregnant Sprague-Dawley rats on days 7--16 of gestation (sperm = day 1). Applications were made 4 times daily in volumes of 0.25 or 0.50 ml 2-ethoxyethanol. Females exhibited ataxia following treatment of the high-dose group, and weight gain was significantly (p less than u. 0.001) reduced in the last half of gestation. Litters were collected by caesarian section on day 21 of gestation, and fetuses were examined for external defects. Half of the fetuses were cleared and stained in alizarin red S for skeletal examinations, and half were examined for visceral defects by the Wilson technique. Intrauterine death was 100% in the high-dose group. In the lower dosage group, there was a significant increase in the number of pregnant females with 100% dead implants (p less than 0.001), a significant reduction in the number of live fetuses per litter (p less than 0.001), a significant reduction in fetal body weight (p less than 0.001), and a significant increase in the incidence of skeletal variations (p less than 0.05) and cardiovascular malformations (p less than 0.05).

Abnormalities, Drug-Induced↗
PubMed1981

Testing of selected workplace chemicals for teratogenic potential.

The reproductive toxicity and teratogenic potential of 19 industrial chemicals have been investigated during the past 3 a. Preliminary studies utilizing intraperitoneal treatments of rats on days 1-15 of gestation have been conducted on the following ten chemicals: allyl chloride, bisphenol A, copper naphthenate, ethylene dibromide, hexachlorobutadiene, 2-mercaptobenzothiazole, methyl styrene, naphthalene, 2-nitropropane, and 1,2,3-trichloropropane. Studies utilizing inhalation exposure of rats and rabbits on days 1-19 and 1-24, respectively, of gestation have been conducted on the following nine chemicals: butylene oxide, carbon disulfide, 2-ethoxyethanol, ethyl benzene, methyl bromide, nitrous oxide, styrene oxide, tetrachloroethylene, and trichloroethylene. In the preliminary studies, evidence of teratogenic potential was seen with allyl chloride and bisphenol A, and fetal toxicity was found in the absence of maternal toxicity with methyl styrene and 2-nitropropane. In the inhalation studies, 2-ethoxyethanol was strongly embryotoxic at the higher exposure levels employed and was teratogenic at the lower concentration.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Evaluation of propylene oxide for mutagenic activity in 3 in vivo test systems.

Propylene oxide (CAS No. 75-56-9) was tested for mutagenic activity following vapor exposure using 3 in vivo test systems. Rat dominant lethal and mouse sperm-head morphology assays were conducted using males exposed to propylene oxide at 300 ppm in a dynamic exposure chamber for 7 h per day on 5 consecutive days. A sex-linked recessive lethal test in Drosophila melanogaster employed a 24-h static exposure to propylene oxide at 645 ppm. Male mice were killed 1, 3, 5, 7, and 9 weeks post-exposure for evaluation of sperm-head morphology. Propylene oxide exposure did not result in an increase in abnormal forms. Male rats were mated with 2 virgin females per week for 6 weeks following exposure. A statistically significant increase in preimplantation losses and a statistically significant reduction in the number of living implants in the first post-exposure week did not appear to be treatment related. A highly significant increase in sex-linked recessive lethal mutations was observed in two germ cell stages (mature sperm and developing spermatocytes). These results warrant continued caution in potential human exposure to propylene oxide.

Animals↗