Navegando por Palavras-chave "imunohistoquímica"

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    Análisis inmunohistoquímico del fenotipo celular del retinoblastoma utilizando marcadores de células neurales y gliales
    (Universidade Federal de São Paulo (UNIFESP), 2015-03-31) Alonzo, Maria Eugenia Orellana de [UNIFESP]; Burnier Junior, Miguel Noel Nascentes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Retinoblastoma is the most common intraocular malignant tumor in childhood yet its origin remains unclear. It has been shown that retinoblastoma cells express both mature and immature retinal markers. An immunohistochemical analysis of the cell origin of this particular tumor may yield valuable insight into disease progression. This study aims to determine the origin of retinoblastoma in a large case series and correlate these findings with histopathological prognostic factors. Methods: Thirty nine retinoblastoma cases were histopathologicaly diagnosed and further analyzed by immunohistochemistry using monoclonal antibodies against immature retinal cell marker (SOX-2: SRY-box containing gene 2), mature retinal cell marker (MAP2: microtubule-associated protein 2), and glial cell marker (GFAP: glial fibrillary acidic protein). Histopathological features, including pattern of growth, differentiation, vitreous seeding, choroidal/scleral, optic nerve, and anterior chamber invasion, were evaluated. Two retinoblastoma cell lines were studied using immunocytochemistry staining, with the same markers. Results: Expression of SOX-2 was strong in 97.4% of retinoblastoma cases, while MAP-2 was expressed in 59% of cases. Immunostaining for GFAP was consistent across all cases; positive exclusively in reactive stromal astrocytes interspersed amongst tumor cells. There was no correlation between histopathological prognostic factors and the immunohistochemical markers. Retinoblastoma cell lines showed strong positivity for SOX2 (WERI-1cells 90% and in 70% of Y79 cells). MAP2 was positive in WERI-1 cells and Y79 cells (90%). GFAP was completely negative in both cell lines. Conclusion: These results suggest that the majority of retinoblastomas and the RB cell lines expressed immature rather than mature retinal cell markers. Therefore, these results indicate a neural origin of this particular tumor. In addition, the absence of GFAP positivity in tumor cells further suggests a retinal cell origin of retinoblastoma.
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    Meningioma intracanalicular: diagnóstico por imunohistoquímica
    (ABORL-CCF Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial, 2008-02-01) Borin, Andrei; Okada, Daniel Mochida; Cruz, Oswaldo Laércio Mendonça [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)