Neurotoxicology and teratology
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Neurotoxicol Teratol · Sep 1991
The effect of prenatal cocaine exposure on umbilical cord length in fetal rats.
Umbilical cord length has been considered a reliable indicator of fetal movement. In this study, the effect of prenatal cocaine exposure on umbilical cord length was examined in rats. ⋯ Fetuses exposed to cocaine in utero had significantly shorter umbilical cords than intubated controls, although there were no differences in placental or fetal body weights. These data suggest that prenatal cocaine exposure suppresses fetal movement, which could contribute to some of the long-term effects observed in cocaine-exposed offspring.
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Neurotoxicol Teratol · Jul 1991
Wernicke's encephalopathy and Korsakoff's psychosis: to fortify or not to fortify?
The conventional wisdom suggests that Korsakoff's psychosis, an amnesic disorder associated with prolonged alcohol consumption, is the chronic outcome of a thiamin deficiency first exhibited as Wernicke's encephalopathy. The present paper describes the debate in Australia over whether flour and alcoholic beverages should be fortified with thiamin, in an attempt to prevent Wernicke's encephalopathy and thus Korsakoff's psychosis. We conclude that the scientific evidence linking Wernicke's encephalopathy and Korsakoff's psychosis is tenuous. Certainly, it is not sufficient to support what would amount to mass medication.
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A battery of behavioral tasks, designed to monitor complex "cognitive" functions in nonhuman primates, has been in use for several years at the National Center for Toxicological Research. Subjects performing in this Operant Test Battery (OTB) work for food reinforcers and correct performance in each task contained in the OTB is thought to depend upon a relatively specific brain function. The specific tasks and the functions that they are thought to model are: delayed matching-to-sample (DMTS), short-term memory and attention; incremental repeated acquisition (IRA), learning; temporal response differentiation (TRD), time perception; progressive ratio (PR), motivation; and conditioned position responding (CPR), color and position discrimination. Data from various studies indicate that, in general: 1) OTB responding between subjects follows a normal or near-normal distribution; 2) performance in one task does not correlate very highly with performance in any of the other tasks; 3) females acquire correct OTB responding more rapidly than do males; and 4) the profile of disruption of task performance by acute drug administration varies depending upon drug class.
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Neurotoxicol Teratol · Sep 1987
Clinical Trial Controlled Clinical TrialAbsence of symptoms with carboxyhemoglobin levels of 16-23%.
It has been generally accepted that carboxyhemoglobin levels between 10-20% produce mild headaches, dizziness and/or nausea. Experimental double blind exposures of 18 healthy, nonsmoking young men at rest to 7,000-24,000 ppm CO, designed to elevate COHb to 15-20% in 3-5 minutes, were followed by exposure to 232 ppm CO designed to maintain COHb level for a total of 130 minutes. ⋯ Subjects were especially queried about headache, dizziness and nausea. The symptoms which were previously reported in clinical studies of CO poisoning may have resulted from CO exposure in combination with (a) exposure to other substances, (b) stress due to the event that precipitated medical attention or (c) higher COHb levels before the first blood sample was taken.