963 resultados para Tumores cerebrais


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Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

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Nota en cubierta: "Certamen literario de 1846. Disertante Dn. Benito Garcia de los Santos. Arguyentes Sres. Claramunt y Torrellas"

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Tesis Univ. Río de Janeiro.

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Tesis Univ. Río de Janeiro.

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Mode of access: Internet.

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The development and progression of odontogenic tumors have been associated with an imbalance in the activity of growth factors, adhesion molecules, extracellular matrix proteins and their degradation enzymes, angiogenic factors and osteolytic. Some studies have shown that interaction relationships inductive epithelial / mesenchymal determinants of Odontogenesis are mimicked by these tumors. The objective of this research was to investigate the immunolocalization of growth factors (BMP-4 and FGF-8) and Sindecan-1 structural protein in a series of odontogenic tumors presenting different biological behaviors, to contribute to a better understanding of the role of these proteins in tumor development. The sample consisted of 21 of the solid ameloblastoma, odontogenic keratocysts 19 and 14 odontogenic adenomatoid tumors. Increased Sindecan-1 immunostaining was seen in the epithelium of the lesions when compared with mesenchyme. In ameloblastoma and odontogenic keratocysts, this expression was higher than in AOT. Epithelial expression of BMP4 showed quantitatively similar in the three studied lesions; however, when anlisada mesenchymal immunoreactivity, was detected significant higher expression when compared to the ameloblastoma keratocysts. In ameloblastoma, mesenchymal expression was predominantly (p = 0.008), while in keratocyst higher expression in the epithelium was observed (p = 0.046). In all injuries, strong or moderate correlation was observed in the BMP-4 immunoreactivity in the epithelium and mesenchyme. FGF-8, no injury was observed difference between the immunoreactivity in the epithelium or mesenchyme, however in ameloblastoma positive correlation was found (Spearman correlation, rho = 0.857, p <0.001). The results of this study suggest that the three evaluated biomarkers actively involved in the pathogenesis of lesions, especially the expression of ameloblastomas indicating a strong interaction between parenchymal and stromal cells which may contribute to its marked aggressiveness.

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INTRODUCTION AND OBJECTIVE: The study of biological behavior of odontogenic lesions is essential to the establishment of appropriate therapeutic approach and prognosis. The production of extracellular matrix metalloproteinases (MMPs), angiogenesis and cell proliferation contribute to tumor growth. This paper aims to review the literature on odontogenic tumors (OT) selected according to the new World Health Organization classification (WHO- 2005) by evaluating the expression of MMPs, angiogenic and cell proliferation. Furthermore, it aims to verify the relation between these markers and the biological behavior of these lesions. RESULTS: it was found that MMPs -1, -2, -7, -9 and -26 had a higher expression in both epithelial component and stroma, and 13 particularly in the stroma. Increased angiogenesis was observed in more aggressive OT. CD105 expression was higher in keratocystic odontogenic tumour (KOT) and CD34 in solid ameloblastomas (SA). It was observed a higher expression of Ki-67 and p53 in SA and KOT and a low cell proliferation rate in the adenomatoid odontogenic tumour (AOT). CONCLUSION: These results show that MMPs are involved in invasion and recurrence of some odontogenic lesions and are associated with the biological behavior of these tumors. Angiogenesis is critical to provide support to cell proliferation and these concomitant events are correlated with different levels of biological behavior in OT when compared to odontogenic cysts, hence the use of angiogenic inhibitors may be a potential therapeutic approach in these lesions.

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INTRODUCTION AND OBJECTIVE: The study of biological behavior of odontogenic lesions is essential to the establishment of appropriate therapeutic approach and prognosis. The production of extracellular matrix metalloproteinases (MMPs), angiogenesis and cell proliferation contribute to tumor growth. This paper aims to review the literature on odontogenic tumors (OT) selected according to the new World Health Organization classification (WHO- 2005) by evaluating the expression of MMPs, angiogenic and cell proliferation. Furthermore, it aims to verify the relation between these markers and the biological behavior of these lesions. RESULTS: it was found that MMPs -1, -2, -7, -9 and -26 had a higher expression in both epithelial component and stroma, and 13 particularly in the stroma. Increased angiogenesis was observed in more aggressive OT. CD105 expression was higher in keratocystic odontogenic tumour (KOT) and CD34 in solid ameloblastomas (SA). It was observed a higher expression of Ki-67 and p53 in SA and KOT and a low cell proliferation rate in the adenomatoid odontogenic tumour (AOT). CONCLUSION: These results show that MMPs are involved in invasion and recurrence of some odontogenic lesions and are associated with the biological behavior of these tumors. Angiogenesis is critical to provide support to cell proliferation and these concomitant events are correlated with different levels of biological behavior in OT when compared to odontogenic cysts, hence the use of angiogenic inhibitors may be a potential therapeutic approach in these lesions.

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Introdução – A dosimetria in vivo é útil na medição da dose administrada aos doentes durante o tratamento, avaliando diferenças significativas entre a dose prescrita e a dose administrada no volume alvo, bem como nos órgãos de risco. Objetivo – Comparar a dose medida com a dose calculada em doentes com tumores de mama com e sem filtro físico. Métodos – Realizaram-se medições da dose na pele, utilizando díodos tipo–p, para os campos tangenciais e respetivos field-in-field em 38 doentes. Resultados – Verificaram-se diferenças estatisticamente significativas nos campos tangenciais open (ρ=0,000). Discussão – Estudos reportam desvios sistemáticos significativos entre a dose calculada e a dose medida. Conclusão – Com este estudo conclui-se que não existe influência nas doses devido à presença do filtro físico.