Astrocytoma
Mostrando 13-24 de 155 artigos, teses e dissertações.
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13. Immunohistochemical study of the molecular alterations in the astrocytic tumors: tumorigenic pathways and resistance markers / Estudo imuno-histoquímico das alterações moleculares nos tumores astrocíticos: vias tumorigênicas e indicadores de resistência
O presente estudo objetivou avaliar a expressão de genes envolvidos no processo tumorigênico e nos mecanismos de quimiorresistência dos tumores astrocíticos. Procedeu-se análise clínico-epidemiológica, avaliação histopatológica e estudo imuno-histoquímico das proteínas Ki-67, c-Myc, GFAP, p53, p21WAF1/CIP1, p27KIP1, Bcl-2, Bax, EGFR, erbB-2, p21R
Publicado em: 2005
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14. Dimensionality reduction using mean conditional entropy applied for bioinformatics and image processing problems / "Redução de dimensionalidade utilizando entropia condicional média aplicada a problemas de bioinformática e de processamento de imagens"
Dimensionality reduction is a very important pattern recognition problem with many applications. Among the dimensionality reduction techniques, feature selection was the main focus of this research. In general, most dimensionality reduction methods that may be found in the literature privilegiate cases in which the data is linearly separable and with only tw
Publicado em: 2004
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15. Fas ligand expression by astrocytoma in vivo: maintaining immune privilege in the brain?
Astrocytomas are among the most common brain tumors that are usually fatal in their malignant form. They appear to progress without significant impedance from the immune system, despite the presence of intratumoral T cell infiltration. To date, this has been thought to be the result of T cell immunosuppression induced by astrocytoma-derived cytokines. Here,
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16. Susceptibility to astrocytoma in mice mutant for Nf1 and Trp53 is linked to chromosome 11 and subject to epigenetic effects
Astrocytoma is the most common malignant brain tumor in humans. Loss of the p53 signaling pathway and up-regulation of the ras signaling pathway are common during tumor progression. We have shown previously that mice mutant for Trp53 and Nf1 develop astrocytoma, progressing to glioblastoma, on a C57BL/6J strain background. In contrast, here we present data t
National Academy of Sciences.
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17. Cell surface antigens of human astrocytoma defined by mouse monoclonal antibodies: identification of astrocytoma subsets.
The surface antigens of cultured human malignant astrocytomas were analyzed by using mouse monoclonal antibodies. BALB/c mice were immunized repeatedly with either SK-MG-1 [a glial fibrillary acidic protein (GFA)-negative astrocytoma line] or SK-AO2 (a GFA-positive astrocytoma line). After fusion with NS/1 mouse myeloma cells, 12 antibody-producing clones we
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18. Cerebral astrocytoma in association with HIV infection.
Cerebral astrocytoma has been found in two patients with AIDS related conditions. The fortuity of this unusual association is discussed, insofar as immunosuppression could favour the growth of certain neoplasms.
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19. Serological analysis of cell surface antigens of malignant human brain tumors
Sera from 30 patients with astrocytoma were tested for antibody reacting with cell surface antigens of cultured autologous astrocytoma cells. Ten percent of the patients had antibody detectable by mixed hemadsorption assays, ≈50% by immune adherence and protein A assays, and 100% by anti-C3-mixed hemadsorption assays. Absorption analysis of reactive sera w
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20. Expression of the somatostatin gene in human astrocytoma cell lines.
Somatostatin (somatotropin release-inhibiting hormone; SRIH) has been demonstrated in neurons of the central nervous system (CNS) as well as in endocrine cells of the pancreas and gastrointestinal tract and can suppress various immune functions including lymphocyte proliferation, immunoglobulin synthesis, and cytokine production. Since astrocytes possess ant
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21. Dominant-negative mutants of platelet-derived growth factor revert the transformed phenotype of human astrocytoma cells.
Malignant astrocytoma is the most common primary human brain tumor. Most astrocytomas express a combination of platelet-derived growth factor (PDGF) and PDGF receptor which could close an autocrine loop. It is not known whether these autocrine loops contribute to the transformed phenotype of astrocytoma cells or are incidental to that phenotype. Here we show
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22. Astrocytic differentiation in medulloblastoma.
A case of cerebellar medulloblastoma with transitional features towards malignant fibrillary astrocytoma is described. In the cerebellum the tumour is characterised by extensive subpial infiltration with cells of undifferentiated type, and the astrocytic component could only be identified by a positive glial fibrillary acidic protein reaction. In the brainst
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23. Recurrence of astrocytoma of optic nerve after 48 years.
A tumour presumed to be a juvenile glioma of the optic nerve was removed by a Kronlein procedure from a 4-year old boy in 1925. In 1973 a severe proptosis made it necessary to remove the atrophic eye and a large retro-ocular tumour. Histological examination, supported by electron microscopy, showed the second tumour to be an anaplastic pilocytic astrocytoma.
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24. Astrocyte-Specific Inactivation of the Neurofibromatosis 1 Gene (NF1) Is Insufficient for Astrocytoma Formation
Individuals with the neurofibromatosis 1 (NF1) inherited tumor syndrome develop low-grade gliomas (astrocytomas) at an increased frequency, suggesting that the NF1 gene is a critical growth regulator for astrocytes. In an effort to determine the contribution of the NF1 gene product, neurofibromin, to astrocyte growth regulation and NF1-associated astrocytoma
American Society for Microbiology.