Regional differences in astrocyte activation in HIV-associated dementia.

Since astrogliosis is a histological marker usually observed in HIV-associated dementia (HIV-D), we decided to investigate the potential relationship between the expression of glial fibrillary acidic protein (GFAP) and the regional distribution of cells positive (+) for this specific marker of astrocyte activation. Histological sections of brain tissues obtained at necropsy from 5 HIV-D patients and 5 age-matched controls without history of neuropsychiatric illness were immunostained with peroxidase. Mean numbers of GFAP(+) astrocytes were significantly increased in entorhinal cortex, hippocampus and subcortical white matter of patients, but values in frontal cortex and basal ganglia were similar to those of controls.

Immunochemical and morphometric features of astrocyte reactivity vs. plaque location in Alzheimer's disease.

The quantitative relationship between glial fibrillary acidic protein (GFAP) hyper-reactivity and beta-amyloid protein (betaAP) deposition was investigated by double immunoperoxidase labeling of hippocampal and entorhinal cortex sections from five Alzheimer's disease (AD) cases and five age-matched controls. betaAP plaques, which were absent in controls, were found in all AD samples, without significant differences in number or perimeter according to their location among the regions studied. In contrast, the mean number of GFAP (+) cells was significantly greater in the hippocampus than in the entorhinal cortex from AD cases (49 vs.

Immunochemical expression of proliferative cell nuclear antigen in aging cultured astrocytes.

Cell differentiation degree and mitotic activity were sequentially assessed by immunoperoxidase labeling of glial fibrillary acidic protein (GFAP) and proliferative cell nuclear antigen (PCNA), respectively, in rat brain cultured astrocytes maintained up to 60 days in vitro (DIV) of first subculture, or weekly passaged until their 12th subculture. Cell count was performed through a 0.01 mm2 section reticule and morphometric analysis with a stereological grid.