Biomedical subjects

F F Cruz-Sanchez

Publications and source records attributed to F F Cruz-Sanchez.

21 records · Page 2Linked to original sources

PubMed1988

An immunohistological study of 66 ependymomas.

Sixty-six ependymomas were examined immunohistologically to determine their distribution of glial fibrillary acidic proteins, S-100 protein and vimentin. The neoplasms were subdivided into four groups: (1) ependymomas from the cauda equina, predominantly of the myxopapillary type; (2) benign ependymomas; (3) malignant ependymomas; and (4) ependymoblastomas. Marked differences in antigen reactivity were observed between each group. The intensity of the reaction with the three antibodies was strongest in malignant ependymomas. Ependymomas from the cauda equina showed a patchy distribution of positivity for the three antigens in cells surrounding blood vessels but there was no staining of collagenous septa or the myxoid areas. In ependymoblastomas, the cells of the rosettes were negative for glial fibrillary acidic protein, but there was focal positivity for vimentin and S-100. Other areas showed tumour cells containing moderate amounts of vimentin and small amounts of S-100, and a few bands of filaments positive for glial fibrillary acidic protein. The cytogenetic and biological implications of these findings are discussed.

Cauda Equina↗

PubMedDate not supplied

Plasticity of the nigrostriatal system in MPTP-treated mice. A biochemical and morphological correlation.

In order to compare the recovery capacity of the nigrostriatal system between adult and old mice, MPTP hydrochloride was administered to 48 BL/C57 male mice, which were sacrificed 24 h or 10 d after the second dose. The animals were divided into four groups, based on age (adult or old) and moment of sacrifice (24 h or 10 d). The detailed morphology of the neurons and the cellular processes of the substantia nigra pars compacta and the striatum were studied using the Golgi method. Immunostaining with a polyclonal glial fibrillary acidic protein antiserum using the peroxidase-antiperoxidase technique was performed to study the glial response. Striatal catecholamines were determined to correlate the biochemical data with the morphological changes. Significant neuronal changes of cellular processes were observed in substantia nigra pars compacta from all MPTP-treated mice, consisting of swelling and distortion of cellular bodies, discontinuous thickness, and nodulations of dendrites with baded aspect. Axons showing focal swelling and nodulations were also found in the neuropil of silver impregnated striata. Marked gliosis with reactive astrocytes in substantia nigra and striatum from all the old treated mice was found. Recovery was only observed in adult mice sacrificed 10 d after withdrawal. At this time, all the old MPTP-treated mice showed marked neuronal changes and a persistent marked gliosis. As expected, 24 h after the MPTP treatment, a marked depletion of dopamine and its metabolites was found in all the animals; at 10 d, the depletion was partially reversed in the adult group. These data correlate well with the observed morphological changes. Our results suggest that, in mice, deterioration of dendritic and axonal neuropil constitutes a significant causal factor of the MPTP neurotoxicity. These features are related to the age of the animals and the integrity of the plasticity phenomena, which appear to be altered in old mice.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMedDate not supplied

Epithelial membrane antigen expression in ependymomas.

Twenty-seven ependymomas were studied (18 'benign' or low grade and nine 'malignant' or high grade) by means of a monoclonal antibody to epithelial membrane antigen (E29) and an antiserum to glial fibrillary acidic protein (GFAP). The E29 antibody reacted with 'benign' ependymomas but not with 'malignant' ones. Staining was located on the cell surface and especially that facing rosette lumina. Cells forming papillary structures and ependymal epithelium showed a similar distribution of staining. Glial fibrillary acidic protein (GFAP) reactivity was seen in all tumours, with a perivascular accentuation in 'malignant' ones. Staining occurred in the cytoplasm of scattered cells and in those forming papillary structures, ependymal epithelium and rosettes. Our results may have implications in relation to the cytogenesis of these tumours and may also be useful in the histological assessment of 'benign' versus 'malignant' ependymomas.

Brain Neoplasms↗