968 resultados para Neoplasias de glândulas salivares


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Pós-graduação em Biopatologia Bucal - ICT

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Salivary gland neoplasms exhibit a wide variety of biological behavior and a high morphological diversity raises the interest in researching these lesions. The stem cells are the main source for the generation and maintenance of cell diversity, disorders in the regulation of these cells can lead to the production of altered stem cells, termed cancer stem cells capable of generate the tumor. Researches on cancer stem cells and associated proteins have been developed in some oral cancers; however, their role in salivary gland neoplasms is not well established. Thus, the aim of this study was to identify the tumor parenchyma cells exhibiting stem cell characteristics, by evaluating the immunoreactivity of OCT4 and CD44, in a number of cases of salivary gland neoplasms. The sample consisted of 20 pleomorphic adenomas, 20 mucoepidermoid carcinomas and 20 adenoid cystic carcinoma located in minor and major salivary glands. The expression of OCT4 and CD44 was evaluated by the percentage of positive cells (PP) and the intensity of expression (IE), it is realized the sum of the scores, resulting in the total score immunostaining (PIT) ranging 0-7. All studied cases showed positive expression of OCT4 and CD44 and higher values than the control groups. It was observed that for OCT4 luminal cells and non-luminal were immunostained in the case of pleomorphic adenomas and adenoid cystic carcinoma. Already the immunoreactivity of CD44 was particularly evident in the non-luminal cells of these lesions. In mucoepidermoid carcinomas for both markers, there was immunoreactivity in squamous and intermediate cells and absence of staining mucous cells. For both markers, a statistically significant higher immunostaining was verified in neoplasms located in the major salivary glands compared with lesions in the minor salivary (p<0.001). At the total sample and in the group of minor salivary glands, malignant neoplasms exhibited higher immunoreactivity for OCT4 than pleomorphic adenoma. However, there was no statistically significant difference between the lesions and between their classifications histomorphologic. Analyzing the correlation between OCT4 and CD44 immunoexpressions, a statistically significant moderate positive correlation (r = 0.444) was observed. The high expression of OCT4 and CD44 may indicate that these proteins play an important role in identifying cancer stem cells, allowing a prediction of biological behavior of salivary gland neoplasms.

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The expression of glucose transporter protein 1 (GLUT-1), as well the angiogenesis has been associated to clinical behavior and aggressiveness in tumors of various origin. It is believed that the expression of this protein denotes metabolic demand of the tumor cells and, thus its influence upon the formation of new blood vessels. Pleomorphic adenoma (PA) and the adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC) represent, respectively, the most commom benign and malignant tumors of salivary glands. The aim of this study was to analyze and compare the immunohistochemical expression of GLUT-1 and its correlation with angiogenesis in cases of PAs, ACCs and MECs considering their histological grades. The sample consisted of 20 PAs, 20 ACCs and 10 MECs. The cases were analyzed and classified according to their histological grades. The expression of GLUT-1 was evaluated in the parenchyma lesions, establishing the percentage of immunopositive cells, according to the following scores: 0 (no cell immunomarked), 1 (up to 25% of tumor cells immunostained), 2 (25 - 50% of tumor cells immunostained) and 3 (more than 50% of tumor cells immunostained). The angiogenic index was analyzed by counting the microvessels immunostained by anti-CD34 antibody, in 5 fields (200X). The analysis of the expression of GLUT-1 in tumor parenchyma showed statistically significant differences between benign and malignant groups (p = 0.022). The average number of microvessels in PAs was 40.4, 21.2 in ACCs and 66.5 in MECs, with significant differences between groups (p <0.001). When compared to the expression of GLUT-1 and angiogenic index as a whole, there was no significant correlation between the number of microvessels and the expression of GLUT-1 (r = 0.211, p = 0.141). In conclusion, the results of this study suggest not only that differences in biological behavior between PAs, ACCs and MECs may be associated to the expression of GLUT-1, but also that benign and malignant salivary gland present differences in the average number of microvessels, with higher levels considered more aggressive tumors. Furthermore, the number of newly formed microvessels can be independent of the metabolic demand of the tumor cells

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Foi avaliada, no presente estudo, a prevalência dos casos de tumores benignos e malignos de glândulas salivares maiores e menores que ocorreram na população atendida no hospital Dr. Luiz Antônio Natal/RN, no período de 1989 a 2005, bem como as possíveis associações existentes entre os aspectos clínico e patológicos exibidos pelos referidos tumores, visando à obtenção de parâmetros indicadores de diagnóstico e/ou prognóstico. Dos prontuários dos pacientes foram obtidas todas as informações clínicas necessárias para a realização do trabalho. A análise dos dados revelou que dos 303 tumores de glândula salivar estudados, a maioria (71%) foram benignos, o mais comum foi adenoma Pleomórfico. As médias de idades para os tumores benignos e malignos foi de 49,2 e 58,5 anos, respectivamente. Diferenças estatisticamente significativas entre estes tumores foram observadas para as seguintes variáveis: idade média, o tamanho do tumor e duração da doença. Em relação ao tamanho do tumor, carcinoma mucoepidermoide mostrou-se 1,74 vezes menor que o de outros tumores malignos. Uma associação entre o diagnóstico histológico e variável consistência do tumor foi observada. Os dados apresentados neste estudo são relevantes para a compreensão das diversas características exibidas por estes tumores, já que corroboram uma série de estudos anteriores

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The balance between the expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) has been related to various physiological and pathological processes, including salivary gland morphogenesis and tumor invasion and metastasis processes. Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) respectively represent benign and malignant neoplasias of salivary glands. Although they share the same cell origin, they present distinct biological behavior. The aim of this study was to compare the immunohistochemical expression of MMPs -2, -7, -9 and -26, and of TIMPs -1 and -2, in cases of PA and ACC of minor salivary glands. Twenty cases of PA and twenty cases of ACC were assessed according to the presence, intensity and location of MMPs and TIMPs in the tumor parenchyma. Most of the PAs and ACCs presented a high expression of MMP -2, -7, -9 and -26 and of TIMP -1 and -2, predominantly located in tumor cells. There was no significant difference in the expression of MMPs -2 (p=0.359), -7 (p=0.081) and -26 (p=0.553), as well as of TIMPs -1 (p=0.657) and -2 (p=0.248), between the parenchyma of PAs and ACCs. However, MMP-9 showed a significant difference of expression between the two tumors, with the ACC showing more intense marking for this gelatinase (p=0.041). The strong expression of MMP-9 observed in the parenchyma suggests that this gelatinase may play an important role in the biological behavior of these tumors. On the other hand, although there was no significant difference between the marking of MMP -2, 7 and 26 in the studied tumors, the data, when analyzed as a whole, suggest that these proteases may take part in the process of tissue remodeling in both tumors, but do not present a direct relation with the pattern of aggressiveness of ACC. Nonetheless, matrilisins may indirectly influence the behavior of this tumor due to their capacity of activating MMP-9, strongly expressed in the parenchyma of ACC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

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Relatou-se o efeito do transplante de glândulas salivares menores (TGSM) em cães portadores de ceratoconjuntivite seca (CCS) e estudaram-se os efeitos da secreção dessas glândulas usadas como alternativa de lubrificação ocular. A aplicação da técnica foi satisfatória, uma vez que resultou em melhora no quadro clínico oftalmológico sem que houvesse mínimas intercorrências pós-operatórias.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)