Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Sep 2000
Comparative StudyAge as a susceptibility factor in the striatal dopaminergic neurotoxicity observed in the mouse following substituted amphetamine exposure.
A number of substituted amphetamines, including methamphetamine (METH) are considered dopaminergic neurotoxicants. METH causes long-term depletions of striatal dopamine (DA) and its metabolites (DOPAC and HVA) that are accompanied by other changes indicative of nerve terminal degeneration. These include argyrophilia as detected by silver degeneration stains and an elevation in glial fibrillary acidic protein (GFAP), a marker of reactive gliosis in response to injury, as well as a long-term decrease in tyrosine hydroxylase (TH) protein levels. ⋯ In contrast, the usual neurotoxic regimen of d-METH was minimally effective in inducing GFAP elevations (49% over control) in one-month-old mice, despite elevations in body temperature equivalent to those observed in older mice. Although increasing the dosage of d-METH (20 to 80 mg/kg) did increase the GFAP response (100% over control), it was still well below that usually exhibited at the usual neurotoxic dosage (300-400% over control) in fully mature mice. These data suggest maturity of striatal dopamine systems may be an essential element in the striatal damage induced by the neurotoxic amphetamines.
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Ann. N. Y. Acad. Sci. · May 2000
Comparative StudyTotal body dual X-ray absorptiometry is a good measure of both fat mass and fat-free mass in liver cirrhosis compared to "gold-standard" techniques. Melbourne Liver Group.
Liver cirrhosis is a condition in which overnutrition, edema, and undernutrition can coexist simultaneously, or successively, over a period of time, giving rise to alterations in body composition, as well as systemic and multiorgan manifestations. We undertook a cross-sectional study of body composition in 198 adult patients with liver cirrhosis (140 males, mean age 53.6, range 31-85 years; and 58 females, mean age 58.4, range 36-79 years). The patients had cirrhosis of differing etiology and different stages of severity. ⋯ In cirrhosis, DXA is a good and widely available method to assess both fat mass and fat-free mass. However, it cannot give information about the quality of the FFM, particularly its water content. The bedside methods of anthropometry and bioelectrical impedance, both SFBIA and MFBIA, are poor methods of measuring body composition in patients with liver cirrhosis, whereas whole body gamma counting, although not widely available, also significantly differs from the gold-standard method of assessment of fat-free mass and fat mass in liver cirrhosis.