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Genetic variability in the dopaminergic and neurotrophic systems could contribute to age-related impairments in executive control and memory function. In this study we examined whether genetic polymorphisms for catechol-O-methyltransferase (COMT) and brain-derived neurotrophic factor (BDNF) were related to the trajectory of cognitive decline occurring over(More)
Fourteen organophosphorus esters (OPs) were evaluated for their potential to cause organophosphorus ester induced delayed neurotoxicity (OPIDN) when administered dermally and/or orally to white leghorn hens. The compounds were chlorpyrifos, DEF, dichlorvos, dimethoate, EPN, ethoprop, fenthion, isofenphos, leptophos, merphos, ronnel, tetrachlorvinphos,(More)
The effects of desbromoleptophos, fenitrothion, and fenthion on brain acetylcholinesterase (AChE), brain neurotoxic esterase (NTE), and walking were investigated in immature chicks, below the age of organophosphorus ester-induced delayed neurotoxicity (OPIDN). Seventy-five milligrams per kilogram of the delayed neurotoxicant desbromoleptophos (DBL) and 100(More)
Standard developmental toxicology bioassays are designed to identify agents with the potential to induce adverse effects and include dose levels that induce maternal toxicity. The work reported here was undertaken to evaluate the relationship of maternal and fetal toxicity. It constitutes an analysis of 125 developmental toxicity bioassays in the mouse,(More)
5-Azacytidine (5-aza), a chemical that is incorporated into DNA and RNA with consequent alterations in the expression of mammalian genes, was administered to pregnant Sprague-Dawley rats on single days during gestation. Doses of 0.5, 1, and 2 mg/kg were given by intraperitoneal injection on d 9, 10, 11, or 12. Dams were killed on d 20 of gestation and(More)
DNA methylation is a probable mechanism for regulating gene expression, and alterations in methylation may significantly affect embryonic development. We administered the cytidine analogue 5-aza-2'-deoxycytidine (dAZA), a specific and potent demethylator of DNA, to pregnant mice to determine its teratogenicity and effects on embryonic cell death and cell(More)
Retinoic acid (RA) plays an important role in embryogenesis, by regulating morphogenesis, cell proliferation, differentiation, and extracellular matrix production. RA exposure on gestational day (GD) 12 in CD-1 mice results in delayed palatal shelf elevation and subsequent clefts in the secondary palate. Given the dynamic and complex nature of palate(More)
5-Aza-2'-deoxycytidine (d-AZA) replaces cytidine in DNA thereby altering gene expression by passively removing methyl groups. This study determined the temporal patterns of morphological defects induced by d-AZA in mice. The dosages (0, 0.3, or 1.0 mg/kg) were administered by a single i.p. injection on gestational days (GD) 8, 9, 10, or 11. Mice were killed(More)
Cyclophosphamide (CP) administered ip to pregnant mice on day 10 of gestation (day of plug = day 0) is teratogenic (exencephaly, cleft palate, and limb malformations) at 20 mg/kg and embryolethal at higher doses. In the present study, CP was administered at 1, 5, 10, or 20 mg/kg on day 10 of gestation. Embryos were removed at 8 and 28 hr postdosing, and two(More)