Manuel Velasco - Academia.edu (original) (raw)
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Papers by Manuel Velasco
Cancer, 1980
The presence and distribution of glial fibrillary acidic protein in fixed, paraffin embedded tiss... more The presence and distribution of glial fibrillary acidic protein in fixed, paraffin embedded tissue were studied in 85 human intracranial neoplasms, using the peroxidase-anti-peroxidase method. In some cases, indirect immunofluorescence of frozen sections was used as well. In normal tissue, only the cell processes and perikarya of fibrous astrocytes were stained. lmmunostaining was also observed in the following glial neoplasms: astrocytomas (all varieties), astroblastoma, subependymal giant cell astrocytoma, subependymoma, glioblastoma multiforme and ependymoma. The astrocytic elements of mixed gliomas and of medulloblastomas undergoing glial differentiation were likewise strongly stained. In contrast, oligodendrogliomas, meningiomas, pituitary adenomas, sarcomas, lymphomas and metastatic carcinomas were negative. Either a perikaryal or a diffuse fibrillary staining pattern was observed. Combination of the two patterns occasionally occurred. The perikaryal staining was prominent in gemistocytic astrocytomas and in astroblastomas. A distinct negative correlation existed between the degree of anaplasia and the intensity of immunostaining.
Journal of Neuropathology and Experimental Neurology, 1982
The presence of glial fibrillary acidic protein (GFAP) was studied in human pituitary glands with... more The presence of glial fibrillary acidic protein (GFAP) was studied in human pituitary glands with the peroxidase-antiperoxidase (PAP) method. Positive reaction was observed in cells and processes of the neurohypophysis, in occasional cells lining the Rathke's cysts of the pars intermedia, and in scattered star-shaped cells and small follicles of the pars distalis. GFAP immunoreactivity was sparse and variable in amount from case to case. An increase in GFAP-immunoreactivity was observed as a reaction to injury. GFAP-positive cells were seen within and around pituitary adenomas regardless of their secretory cell type. Evidence is presented to indicate that these cells do not contain conventional pituitary hormones. It is postulated that the GFAP-positive cells of the pars distalis are nonsecretory elements, identical to the folliculostellate cells. They may become visible by immunostaining following increased synthesis of GFAP. The latter may be a response to cell injury or metabolic changes in adjacent secretory elements. A similar reaction in pituicytes may explain the appearance of immunoreactive GFAP in the neural lobe. The presence of GFAP in the adenohypophysis suggests that some of their cells are neuroectodermal in origin.
Journal of Neurochemistry, 1981
Abstract: Antisera raised to the 68,000, 145,000 and 200,000 molecular weight subunits of rat neu... more Abstract: Antisera raised to the 68,000, 145,000 and 200,000 molecular weight subunits of rat neurofilaments were used for immunochemical staining of polypeptides separated by one- and two-dimensional gel electrophoresis. It was found that each antiserum reacts intensely with its corresponding neurofilament subunit and weakly with the other two subunits. All the antisera also react with a polypeptide of molecular weight 57,000 present in neurofilament-rich preparations from both rat spinal cord and peripheral nerve. This polypeptide is different from either tubulin or vimentin and may represent a neurofilament breakdown product, since it varied in amount from preparation to preparation. The three antisera also reacted with the polypeptide subunits of chicken and goldfish neurofilament despite the considerable difference in molecular weight between these subunits and those of mammalian neurofilament. Key Words: Neurofilaments–Antibodies–Immunochemical. Autilio-Gambetti L. et al. Immunochemical characterization of antisera to rat neurofilament subunits. J. Neurochem. 37, 1260-1265(1981).
Cancer, 1980
The presence and distribution of glial fibrillary acidic protein in fixed, paraffin embedded tiss... more The presence and distribution of glial fibrillary acidic protein in fixed, paraffin embedded tissue were studied in 85 human intracranial neoplasms, using the peroxidase-anti-peroxidase method. In some cases, indirect immunofluorescence of frozen sections was used as well. In normal tissue, only the cell processes and perikarya of fibrous astrocytes were stained. lmmunostaining was also observed in the following glial neoplasms: astrocytomas (all varieties), astroblastoma, subependymal giant cell astrocytoma, subependymoma, glioblastoma multiforme and ependymoma. The astrocytic elements of mixed gliomas and of medulloblastomas undergoing glial differentiation were likewise strongly stained. In contrast, oligodendrogliomas, meningiomas, pituitary adenomas, sarcomas, lymphomas and metastatic carcinomas were negative. Either a perikaryal or a diffuse fibrillary staining pattern was observed. Combination of the two patterns occasionally occurred. The perikaryal staining was prominent in gemistocytic astrocytomas and in astroblastomas. A distinct negative correlation existed between the degree of anaplasia and the intensity of immunostaining.
Journal of Neuropathology and Experimental Neurology, 1982
The presence of glial fibrillary acidic protein (GFAP) was studied in human pituitary glands with... more The presence of glial fibrillary acidic protein (GFAP) was studied in human pituitary glands with the peroxidase-antiperoxidase (PAP) method. Positive reaction was observed in cells and processes of the neurohypophysis, in occasional cells lining the Rathke's cysts of the pars intermedia, and in scattered star-shaped cells and small follicles of the pars distalis. GFAP immunoreactivity was sparse and variable in amount from case to case. An increase in GFAP-immunoreactivity was observed as a reaction to injury. GFAP-positive cells were seen within and around pituitary adenomas regardless of their secretory cell type. Evidence is presented to indicate that these cells do not contain conventional pituitary hormones. It is postulated that the GFAP-positive cells of the pars distalis are nonsecretory elements, identical to the folliculostellate cells. They may become visible by immunostaining following increased synthesis of GFAP. The latter may be a response to cell injury or metabolic changes in adjacent secretory elements. A similar reaction in pituicytes may explain the appearance of immunoreactive GFAP in the neural lobe. The presence of GFAP in the adenohypophysis suggests that some of their cells are neuroectodermal in origin.
Journal of Neurochemistry, 1981
Abstract: Antisera raised to the 68,000, 145,000 and 200,000 molecular weight subunits of rat neu... more Abstract: Antisera raised to the 68,000, 145,000 and 200,000 molecular weight subunits of rat neurofilaments were used for immunochemical staining of polypeptides separated by one- and two-dimensional gel electrophoresis. It was found that each antiserum reacts intensely with its corresponding neurofilament subunit and weakly with the other two subunits. All the antisera also react with a polypeptide of molecular weight 57,000 present in neurofilament-rich preparations from both rat spinal cord and peripheral nerve. This polypeptide is different from either tubulin or vimentin and may represent a neurofilament breakdown product, since it varied in amount from preparation to preparation. The three antisera also reacted with the polypeptide subunits of chicken and goldfish neurofilament despite the considerable difference in molecular weight between these subunits and those of mammalian neurofilament. Key Words: Neurofilaments–Antibodies–Immunochemical. Autilio-Gambetti L. et al. Immunochemical characterization of antisera to rat neurofilament subunits. J. Neurochem. 37, 1260-1265(1981).