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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Análise histológica e imuno-histoquímica de leiomiomas e leiomiossarcomas de boca / Immunohistochemical and histological analysis of oral leiomyoma and leiomyosarcoma

Prieto-Oliveira, Paula 07 December 2012 (has links)
O objetivo deste estudo foi comparar leiomiomas e leiomiossarcomas de boca por meio de análise histológica e imunoistoquímica, utilizando os marcadores Ki67, p53 e PTEN. A actina de músculo liso foi utilizada para confirmar o diagnóstico. Foram examinados 13 tumores de músculo liso disponíveis nos arquivos do Departamento de Estomatologia da Faculdade de Odontologia da USP, sendo 7 leiomiossarcomas, 4 angioleiomiomas e 2 leiomiomas sólidos. As lâminas foram avaliadas de acordo com o grau de atipia, índice mitótico e presença de necrose. Foi realizada a análise imunoistoquímica para o ki67, p53 e PTEN, por meio da contagem de células positivas em 500 células nas áreas mais representativas. A maioria dos angioleiomiomas não apresentou atipia, mitose ou necrose; atipia discreta foi encontrada nos dois leiomiomas sólidos, um deles com 1 mitose por 10 CGA. Atipia foi observada em todos os leiomiossarcomas, o índice mitótico variou de 0 a 6 mitoses por 10 CGA, e apenas um caso apresentou necrose. Houve positividade para o ki67 em apenas um angioleiomioma e em 5 leiomiossarcomas, o restante dos casos foram negativos. Em relação ao p53, ocorreu leve positividade para um caso de leiomioma sólido e moderada para o outro; a maioria dos angioleiomiomas foram levemente positivos e apenas um foi negativo; todos os leiomiossarcomas foram positivos, 2 com marcação leve, 4 moderada e um intensa. A expressão do PTEN foi negativa em um leiomioma sólido e intensamente positiva em outro; todos os casos de angioleiomioma foram positivos, sendo que 2 demonstraram positividade leve e 2 moderada; 3 leiomiossarcomas apresentaram positividade moderada e 3 intensa, apenas um foi negativo. Nossos resultados sugerem que a marcação para ki67 e p53 são úteis na diferenciação entre leiomiomas e leiomiossarcomas. O mesmo não foi observado para o anticorpo PTEN. / This study aimed to compare oral leiomyomas and leiomyosarcomas by means of histological and immunohistochemical analysis. Cases from the Stomatology Department, School of Dentistry at University of São Paulo were retrieved. For immunohistochemistry Ki67, p53 and PTEN markers were used. Smooth muscle actin was used to confirm the diagnosis. There were 13 smooth muscle tumors: 7 leiomyosarcomas, 4 angioleiomyomas and 2 solid leiomyomas. For morphological analysis, sections were evaluated for atypia, mitotic index and presence of necrosis. Immunohistochemical analysis of Ki67, p53 and PTEN expression was performed by counting 500 positive cells in the most representative areas. Most angioleiomyomas did not present atypia, mitosis or necrosis; mild atypia was found in two solid leiomyomas, one with 1 mitosis per 10 HPF. Atypia was found in all leiomyosarcomas, the mitotic index varied from 0 to 6 mitosis per 10 HPF, and necrosis was found in only one case. Ki67 expression was positive in one angioleiomyoma and 5 leiomyosarcomas, the remaining cases were negative. For p53, one solid leiomyoma was mildly positive and the other showed moderate positivity; most of angioleiomyomas were mildly positive and only one was negative; all leiomyosarcomas were positive, 2 with mild expression, 4 moderate and one intense. PTEN expression was negative in one solid leiomyoma and intensely positive in the other; all angioleiomyomas were positive, with 2 mildly positive and 2 moderately positive; 3 leiomyosarcomas presented moderate positivity and 3 intense, only one was negative. Our results suggest that ki67 and p53 are useful in the differentiation between leiomyoma and leiomyosarcoma. The same was not found for PTEN.
2

Análise histológica e imuno-histoquímica de leiomiomas e leiomiossarcomas de boca / Immunohistochemical and histological analysis of oral leiomyoma and leiomyosarcoma

Paula Prieto-Oliveira 07 December 2012 (has links)
O objetivo deste estudo foi comparar leiomiomas e leiomiossarcomas de boca por meio de análise histológica e imunoistoquímica, utilizando os marcadores Ki67, p53 e PTEN. A actina de músculo liso foi utilizada para confirmar o diagnóstico. Foram examinados 13 tumores de músculo liso disponíveis nos arquivos do Departamento de Estomatologia da Faculdade de Odontologia da USP, sendo 7 leiomiossarcomas, 4 angioleiomiomas e 2 leiomiomas sólidos. As lâminas foram avaliadas de acordo com o grau de atipia, índice mitótico e presença de necrose. Foi realizada a análise imunoistoquímica para o ki67, p53 e PTEN, por meio da contagem de células positivas em 500 células nas áreas mais representativas. A maioria dos angioleiomiomas não apresentou atipia, mitose ou necrose; atipia discreta foi encontrada nos dois leiomiomas sólidos, um deles com 1 mitose por 10 CGA. Atipia foi observada em todos os leiomiossarcomas, o índice mitótico variou de 0 a 6 mitoses por 10 CGA, e apenas um caso apresentou necrose. Houve positividade para o ki67 em apenas um angioleiomioma e em 5 leiomiossarcomas, o restante dos casos foram negativos. Em relação ao p53, ocorreu leve positividade para um caso de leiomioma sólido e moderada para o outro; a maioria dos angioleiomiomas foram levemente positivos e apenas um foi negativo; todos os leiomiossarcomas foram positivos, 2 com marcação leve, 4 moderada e um intensa. A expressão do PTEN foi negativa em um leiomioma sólido e intensamente positiva em outro; todos os casos de angioleiomioma foram positivos, sendo que 2 demonstraram positividade leve e 2 moderada; 3 leiomiossarcomas apresentaram positividade moderada e 3 intensa, apenas um foi negativo. Nossos resultados sugerem que a marcação para ki67 e p53 são úteis na diferenciação entre leiomiomas e leiomiossarcomas. O mesmo não foi observado para o anticorpo PTEN. / This study aimed to compare oral leiomyomas and leiomyosarcomas by means of histological and immunohistochemical analysis. Cases from the Stomatology Department, School of Dentistry at University of São Paulo were retrieved. For immunohistochemistry Ki67, p53 and PTEN markers were used. Smooth muscle actin was used to confirm the diagnosis. There were 13 smooth muscle tumors: 7 leiomyosarcomas, 4 angioleiomyomas and 2 solid leiomyomas. For morphological analysis, sections were evaluated for atypia, mitotic index and presence of necrosis. Immunohistochemical analysis of Ki67, p53 and PTEN expression was performed by counting 500 positive cells in the most representative areas. Most angioleiomyomas did not present atypia, mitosis or necrosis; mild atypia was found in two solid leiomyomas, one with 1 mitosis per 10 HPF. Atypia was found in all leiomyosarcomas, the mitotic index varied from 0 to 6 mitosis per 10 HPF, and necrosis was found in only one case. Ki67 expression was positive in one angioleiomyoma and 5 leiomyosarcomas, the remaining cases were negative. For p53, one solid leiomyoma was mildly positive and the other showed moderate positivity; most of angioleiomyomas were mildly positive and only one was negative; all leiomyosarcomas were positive, 2 with mild expression, 4 moderate and one intense. PTEN expression was negative in one solid leiomyoma and intensely positive in the other; all angioleiomyomas were positive, with 2 mildly positive and 2 moderately positive; 3 leiomyosarcomas presented moderate positivity and 3 intense, only one was negative. Our results suggest that ki67 and p53 are useful in the differentiation between leiomyoma and leiomyosarcoma. The same was not found for PTEN.
3

Prädiktive und prognostische Relevanz von p53 und Ki67 beim lokal fortgeschrittenen Rektumkarzinom cUICC-II/III / Immunhistochemische Analysen im methodischen Vergleich / Predictive and prognostic value of p53 and Ki67 in locally advanced rectal cancer cUICC-II/III / Immunohistochemical analysis and comparison of analysis methods

Posern, Susanna 12 November 2013 (has links)
No description available.
4

Imunoexpressão das proteínas KI67 e p53 em pacientes com retocolite ulcerativa inespecífica tratados clinicamente e cirurgicamente

Cezar Feitosa de Paula Machado, Marcos 31 January 2008 (has links)
Made available in DSpace on 2014-06-12T23:02:31Z (GMT). No. of bitstreams: 2 arquivo4298_1.pdf: 893623 bytes, checksum: 0bcd91f818d9d6a5db4eae01d84b07ed (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os métodos imunohistoquímicos associados aos sistemas computadorizados de análise de imagens tem sido de extrema importância, como ferramentas auxiliares, no estudo da expressão de proteínas relacionadas a neoplasias malignas em pacientes portadores de doenças inflamatórias intestinais. Neste estudo, obtive-se o perfil imunohistoquímico das proteínas p53 e Ki-67 do tecido intestinal de pacientes com colite ulcerativa (n=30) um grupo tratado clinicamente e outro cirurgicamente de ambos os sexos e idade média de 38,5 anos. Os tecidos foram fixados em formalina a 10%, submetidos à rotina histológica e montados em parafina. Fragmentos de tecido (4 μm) foram submetidos à técnica de imunohistoquímica para as proteínas Ki-67 e p53. Os perfis de marcação tecidual foram quantificados através de uma estação de análise de imagem contendo um microscópio óptico equipado com uma câmera digital ambos acoplados a um computador contendo o software OPTIMAS®. Os resultados obtidos demonstram diferenças significativas nos padrões de marcação no tecido inflamado em pacientes tratados clinicamente quando comparados aos tecidos de pacientes tratados cirurgicamente. As proteínas Ki-67 e P-53 indicam marcadores imunohistoquímicos úteis para diferenciação de tecidos de colite ulcerativa que trazem características pré-neoplásicas sugestivas de malignidade
5

“DETERMINACIÓN DEL ANTÍGENO KI67 Y DEL GEN P53 COMO FACTORES PRONÓSTICO DE SOBREVIDA EN PACIENTES CON GLIOBLASTOMA MULTIFORME”

Cortez Alvarado, Karen Magdaly January 2016 (has links)
Objetivos. Determinar la influencia de los marcadores: antígeno Ki67 y del gen p53 como factores pronóstico independiente en la sobrevida de los pacientes con Glioblastoma Multiforme. Materiales y métodos. Se revisó un total de 150 casos de pacientes con diagnóstico preliminar de Glioblastoma Multiforme (GBM) atendidos en el Instituto Nacional de Enfermedades Neoplásicas, entre los años 2008 y 2013 y se seleccionaron 60 casos que cumplían con los criterios de inclusión requeridos, información clínico patológica y seguimiento adecuado. Resultados. La media de edad es de 51 años (8-73 años), conformado por 34 hombres (56.7%) y 26 mujeres (43.3%). La mediana de sobrevida global (SG) es menor en el grupo de pacientes que sobreexpresaron el antígeno Ki67 (>= 20%), frente a los pacientes que tuvieron niveles de expresión moderada del antígeno (>= 10%). (26.5 vs 40 meses). Asimismo, se evidencia que la SG es mayor en los pacientes que expresan positivamente el gen p53 (>20%), frente a los pacientes que no llegaron a expresarlo. (40 vs 30 meses). Conclusiones. Tanto la expresión del antígeno ki67 como la expresión del gen p53 se pueden determinar como factores pronóstico de la sobrevida de pacientes que hayan sido diagnosticados con GBM con el fin de mejorar la calidad de vida de estos pacientes dándoles la posibilidad de recibir un tratamiento más específico acorde a los valores de estos marcadores inmunohistoquímicos.Objectives.To evaluate the influence of markers: Ki67 antigen and p53 gene as independent prognostic factors in the survival of patients with Glioblastom Multiform. Materials and methods. A total of 150 cases of patients with a preliminary diagnosis of Glioblastom Multiform (GBM) treated at the National Institute of Neoplastic Diseases between 2008 and 2013 were reviewed and 60 cases were selected that satisfy the inclusion criteria required, clinical pathological information and adequate follow-up information. Results. The mean age is 51 years (8-73 years), made up of 34 men (56.7%) and 26 women (43.3%). The median overall survival (OS) was lower in the group of patients who overexpressed the Ki67 antigen (> = 20%), compared to the patients who had moderate levels of antigen expression (> = 10%). (26.5 vs. 40 months). As well evidenced that the OS is higher in patients who positively express the p53 gene (> 20%), compared to patients who did not express it. (40 vs. 30 months. Conclusion. Both, the expression of the ki67 antigen and the expression of the p53 gene could be determined as prognostic factors for the survival of patients who have been diagnosed with GBM in order to improve the quality of life of these patients giving them the possibility of receiving a more specific treatment according to the values of these immunohistochemically markers.
6

Studies on neurogenesis in the adult human brain

Andersson, Annika January 2010 (has links)
<p>Many studies on neurogenesis in adult dentate gyrus (DG) have been performed on rodents and other mammalian species, but only a few on adult human DG.  This study is focusing on neurogenesis in adult human DG. To characterize the birth of cells in DG, the expression of the cell proliferation marker Ki67 was examined using immunohistochemistry. Ki67-positive labelling was indeed observed in the granular cell layer and the molecular layer of dentate gyrus and in the hilus of hippocampus, as well as in the subgranular zone (SGZ). The Ki67 positive nuclei could be divided into three groups, based on their morphology and position, suggesting that one of the groups represents neuronal precursors. Fewer Ki67 positive cells were seen in aged subjects and in subjects with an alcohol abuse. When comparing the Ki67 positive cells and the amount of blood vessels as determined by anti factor VIII, no systematic pattern could be discerned. To identify possible stem/progenitor cells in DG a co-labelling with nestin and glial fibrillary acid protein was carried out. Co-labelling was found in the SGZ, but most of the filaments were positive for just one of the two antibodies. Antibodies to detect immature/mature neurons were also used to investigate adult human neurogenesis in DG. The immature marker βIII-tubulin showed a weak expression. The other two immature markers (PSA-NCAM and DCX) used did not work, probably since they were not cross-reacting against human tissue. In summary, this study shows that new cells are continuously formed in the adult human hippocampus, but at a slower pace compared to the rat, and that some of these new cells may represent neuronal precursors.</p>
7

Studies on neurogenesis in the adult human brain

Andersson, Annika January 2010 (has links)
Many studies on neurogenesis in adult dentate gyrus (DG) have been performed on rodents and other mammalian species, but only a few on adult human DG.  This study is focusing on neurogenesis in adult human DG. To characterize the birth of cells in DG, the expression of the cell proliferation marker Ki67 was examined using immunohistochemistry. Ki67-positive labelling was indeed observed in the granular cell layer and the molecular layer of dentate gyrus and in the hilus of hippocampus, as well as in the subgranular zone (SGZ). The Ki67 positive nuclei could be divided into three groups, based on their morphology and position, suggesting that one of the groups represents neuronal precursors. Fewer Ki67 positive cells were seen in aged subjects and in subjects with an alcohol abuse. When comparing the Ki67 positive cells and the amount of blood vessels as determined by anti factor VIII, no systematic pattern could be discerned. To identify possible stem/progenitor cells in DG a co-labelling with nestin and glial fibrillary acid protein was carried out. Co-labelling was found in the SGZ, but most of the filaments were positive for just one of the two antibodies. Antibodies to detect immature/mature neurons were also used to investigate adult human neurogenesis in DG. The immature marker βIII-tubulin showed a weak expression. The other two immature markers (PSA-NCAM and DCX) used did not work, probably since they were not cross-reacting against human tissue. In summary, this study shows that new cells are continuously formed in the adult human hippocampus, but at a slower pace compared to the rat, and that some of these new cells may represent neuronal precursors.
8

Leucoplasia verrucosa proliferativa e carcinoma verrucoso: semelhanças e diferenças histopatológicas e de proliferação celular por Ki67 / Proliferative verrucous leukoplakia and verrucous carcinoma: histopathological similarities and differences and cell proliferation by Ki67

Lara Cristina Oliver Gimenez 25 September 2014 (has links)
Carcinoma verrucoso e leucoplasia verrucosa proliferativa, estão entre as lesões que apresentam difícil diagnóstico diferencial devido às semelhanças histopatológicas que ocorrem em determinada fase de evolução. Existe, para tanto, a necessidade de somar dados clínico-epidemiológicos ao histopatológico a fim de se estabelecer o diagnóstico final. A leucoplasia verrucosa proliferativa caracteriza-se por seu acometimento multifocal, grande potencial de recidiva e perfil progressivo que resulta em alto risco de transformação maligna. Por outro lado, o carcinoma verrucoso, variante de baixo grau do carcinoma epidermoide, é unifocal e dificilmente recidiva. A importância de novos estudos acerca das suas duas lesões mencionadas vem a agregar conhecimento de modo a facilitar um correto diagnóstico e, consequentemente, um apurado prognóstico. A leucoplasia verrucosa proliferativa, por se tratar de lesão com alto potencial de transformação maligna, pode evoluir para carcinoma epidermoide invasivo, menos diferenciado e mais agressivo com consequente prognostico obscuro, ao passo que, o carcinoma verrucoso não incorre em metástases e apresenta um prognóstico mais favorável. Isso posto, com o objetivo de aumentar a precisão diagnóstica, o presente trabalho propôs identificar e quantificar em porcentagem os critérios histopatológicos encontrados na leucoplasia verrucosa proliferativa e no carcinoma verrucoso visando diferenciar morfologicamente as lesões dos dois grupos. Também buscamos comparar os dados epidemiológicos referentes aos casos inseridos no estudo, dentre eles vinte e dois casos de leucoplasia verrucosa proliferativa, dezoito casos de carcinoma verrucoso e dois casos apresentando tanto leucoplasia verrucosa proliferativa quanto carcinoma verrucoso, casos esses com diagnósticos estabelecidos previamente (baseando-se nos dados epidemiológicos somados ao histopatológico). A utilização de um marcador imuno-histoquímico da atividade proliferativa celular, o Ki67, também permitiu uma análise comparativa entre o comportamento biológico de ambas as lesões através de um ensaio quantitativo e qualitativo. A marcação mostrou-se escassa, mas evidente em células mitóticas da leucoplasia verrucosa proliferativa, mostrando, no entanto, maior número de células positivas no carcinoma verrucoso, estas visíveis nas camadas basal e parabasal. Os resultados do presente trabalho permitiram concluir então que o marcador Ki67 pode auxiliar no diagnóstico diferencial entre leucoplasia verrucosa proliferativa e carcinoma verrucoso. Foi possível depreender também que, histologicamente, o carcinoma verrucoso apresenta maior alteração em sua conformação epitelial, bem como maior número de atipias cito-arquiteturais quando comparado à leucoplasia verrucosa proliferativa, que, apesar de seu aspecto morfológico, evolui no sentido de uma potencial transformação maligna, apresentando, por sua vez, maior freqüência de projeções em gota. / Verrucous carcinoma and proliferative verrucous leukoplakia, are among the injuries presenting difficult differential diagnosis due to histopathological similarities that occur at some stage of evolution. There is a need to add clinical, epidemiological and histopathological data to achieve the final diagnosis. Proliferative verrucous leukoplakia is characterized by its multifocal involvement, great potential for relapse and progressive profile that results in malignant transformation high risk. On the other hand, the verrucous carcinoma, which is considered low-grade variant of squamous cell carcinoma, is unifocal and unlikely to return. The importance of new studies on its two mentioned lesions is to generate knowledge aiming at a correct diagnosis and prognosis. The proliferative verrucous leukoplakia, since it is a lesion with high potential for malignant transformation, can develop into less differentiated and more aggressive invasive squamous cell carcinoma with subsequent poor prognosis, whereas the verrucous carcinoma incurs no metastases and presents a more favorable prognosis. Thus, aimed to increase the diagnostic accuracy, the present work looked for to identify and quantify in percentage the histopathological criteria found on proliferative verrucous leukoplakia and verrucous carcinoma, aiming morphologically differentiate the lesions from both groups. We also seek to compare the epidemiological data related to cases included in the study, including twenty-two cases of proliferative verrucous leukoplakia, eighteen cases of verrucous carcinoma and two cases showing both proliferative verrucous leukoplakia as verrucous carcinoma, cases with these diagnoses established previously (based on epidemiological data added to histopathology data). Using a cell proliferation immunohistochemical marker, Ki67, we made a comparative analysis between the biological behavior of both lesions by quantitative and qualitative assay. We saw a few strongly positive mitotic cells in samples of proliferative verrucous leukoplakia, and numerous positive cells observed in the basal and parabasal layers of verrucous carcinoma samples. This study results indicate, then, that the Ki67 marker may help in the differential diagnosis between proliferative verrucous leukoplakia and verrucous carcinoma. It was also possible to conclude that, histologically, the verrucous carcinoma shows greater change in its epithelial conformation and a higher number of cyto-architectural atypia when compared to proliferative verrucous leukoplakia, which, despite its morphological appearance, evolves towards a potential malignant transformation, presenting, in turn, higher drop-shaped rete ridges frequency.
9

Leucoplasia verrucosa proliferativa e carcinoma verrucoso: semelhanças e diferenças histopatológicas e de proliferação celular por Ki67 / Proliferative verrucous leukoplakia and verrucous carcinoma: histopathological similarities and differences and cell proliferation by Ki67

Gimenez, Lara Cristina Oliver 25 September 2014 (has links)
Carcinoma verrucoso e leucoplasia verrucosa proliferativa, estão entre as lesões que apresentam difícil diagnóstico diferencial devido às semelhanças histopatológicas que ocorrem em determinada fase de evolução. Existe, para tanto, a necessidade de somar dados clínico-epidemiológicos ao histopatológico a fim de se estabelecer o diagnóstico final. A leucoplasia verrucosa proliferativa caracteriza-se por seu acometimento multifocal, grande potencial de recidiva e perfil progressivo que resulta em alto risco de transformação maligna. Por outro lado, o carcinoma verrucoso, variante de baixo grau do carcinoma epidermoide, é unifocal e dificilmente recidiva. A importância de novos estudos acerca das suas duas lesões mencionadas vem a agregar conhecimento de modo a facilitar um correto diagnóstico e, consequentemente, um apurado prognóstico. A leucoplasia verrucosa proliferativa, por se tratar de lesão com alto potencial de transformação maligna, pode evoluir para carcinoma epidermoide invasivo, menos diferenciado e mais agressivo com consequente prognostico obscuro, ao passo que, o carcinoma verrucoso não incorre em metástases e apresenta um prognóstico mais favorável. Isso posto, com o objetivo de aumentar a precisão diagnóstica, o presente trabalho propôs identificar e quantificar em porcentagem os critérios histopatológicos encontrados na leucoplasia verrucosa proliferativa e no carcinoma verrucoso visando diferenciar morfologicamente as lesões dos dois grupos. Também buscamos comparar os dados epidemiológicos referentes aos casos inseridos no estudo, dentre eles vinte e dois casos de leucoplasia verrucosa proliferativa, dezoito casos de carcinoma verrucoso e dois casos apresentando tanto leucoplasia verrucosa proliferativa quanto carcinoma verrucoso, casos esses com diagnósticos estabelecidos previamente (baseando-se nos dados epidemiológicos somados ao histopatológico). A utilização de um marcador imuno-histoquímico da atividade proliferativa celular, o Ki67, também permitiu uma análise comparativa entre o comportamento biológico de ambas as lesões através de um ensaio quantitativo e qualitativo. A marcação mostrou-se escassa, mas evidente em células mitóticas da leucoplasia verrucosa proliferativa, mostrando, no entanto, maior número de células positivas no carcinoma verrucoso, estas visíveis nas camadas basal e parabasal. Os resultados do presente trabalho permitiram concluir então que o marcador Ki67 pode auxiliar no diagnóstico diferencial entre leucoplasia verrucosa proliferativa e carcinoma verrucoso. Foi possível depreender também que, histologicamente, o carcinoma verrucoso apresenta maior alteração em sua conformação epitelial, bem como maior número de atipias cito-arquiteturais quando comparado à leucoplasia verrucosa proliferativa, que, apesar de seu aspecto morfológico, evolui no sentido de uma potencial transformação maligna, apresentando, por sua vez, maior freqüência de projeções em gota. / Verrucous carcinoma and proliferative verrucous leukoplakia, are among the injuries presenting difficult differential diagnosis due to histopathological similarities that occur at some stage of evolution. There is a need to add clinical, epidemiological and histopathological data to achieve the final diagnosis. Proliferative verrucous leukoplakia is characterized by its multifocal involvement, great potential for relapse and progressive profile that results in malignant transformation high risk. On the other hand, the verrucous carcinoma, which is considered low-grade variant of squamous cell carcinoma, is unifocal and unlikely to return. The importance of new studies on its two mentioned lesions is to generate knowledge aiming at a correct diagnosis and prognosis. The proliferative verrucous leukoplakia, since it is a lesion with high potential for malignant transformation, can develop into less differentiated and more aggressive invasive squamous cell carcinoma with subsequent poor prognosis, whereas the verrucous carcinoma incurs no metastases and presents a more favorable prognosis. Thus, aimed to increase the diagnostic accuracy, the present work looked for to identify and quantify in percentage the histopathological criteria found on proliferative verrucous leukoplakia and verrucous carcinoma, aiming morphologically differentiate the lesions from both groups. We also seek to compare the epidemiological data related to cases included in the study, including twenty-two cases of proliferative verrucous leukoplakia, eighteen cases of verrucous carcinoma and two cases showing both proliferative verrucous leukoplakia as verrucous carcinoma, cases with these diagnoses established previously (based on epidemiological data added to histopathology data). Using a cell proliferation immunohistochemical marker, Ki67, we made a comparative analysis between the biological behavior of both lesions by quantitative and qualitative assay. We saw a few strongly positive mitotic cells in samples of proliferative verrucous leukoplakia, and numerous positive cells observed in the basal and parabasal layers of verrucous carcinoma samples. This study results indicate, then, that the Ki67 marker may help in the differential diagnosis between proliferative verrucous leukoplakia and verrucous carcinoma. It was also possible to conclude that, histologically, the verrucous carcinoma shows greater change in its epithelial conformation and a higher number of cyto-architectural atypia when compared to proliferative verrucous leukoplakia, which, despite its morphological appearance, evolves towards a potential malignant transformation, presenting, in turn, higher drop-shaped rete ridges frequency.
10

Régulation épigénétique de la machinerie de transcription de l'ARN polymérase III par l'histone désacétylase SIRT1 / Epigenetic regulation of polymerase III RNA transcription machinery by histone deacetylase SIRT1

Oury, Julien 28 September 2012 (has links)
SIRT1, appartenant à la famille des sirtuines, est une déacétylase NAD-dépendante, jouant un rôle essentiel dans le contrôle de l’expression génique. En plus de modifier les histones, SIRT1 peut affecter l’activité de certains facteurs de transcription et leurs gènes cibles. Une question fondamentale est de comprendre le mécanisme moléculaire par lequel SIRT1 contrôle l'expression des gènes impliqués dans la prolifération cellulaire et le métabolisme énergétique. Pour identifier les partenaires protéiques de SIRT1, nous avons utilisé la méthode de purification TAP-TAG à partir d'une fraction nucléaire soluble et d'une fraction ancrée à la chromatine de cellules Mef exprimant stablement une copie ectopique de SIRT1 (e-SIRT1). Nous avons ainsi pu identifier un complexe SIRT1 associé à la fois au facteur de prolifération cellulaire Ki67, et à la sous-unité TFIIIC, nécessaire à l'assemblage du complexe de pré-initiation de l'ARN Polymérase III. En délétant sirt1, et en inhibant spécifiquement l'expression de Ki67, nous avons montré que la machinerie de transcription de l'ARN Polymérase III et la prolifération cellulaire étaient fortement affectées. L'ensemble de mes résultats démontre très clairement que SIRT1, Ki67, et TFIIIC sont au sein d'un même complexe protéique, SIRT1 et Ki67 agissant de manière coordonnée pour réguler le niveau d'expression des SINEs et des LINEs, transcrits issus de la machinerie de transcription de l'ARN Polymérase III. / SIRT1, member of the sirtuins family, is an NAD-dependent deacetylase, playing an essential role in controlling gene expression. In addition to modifying histones, SIRT1 can affect the activity of several transcription factors and their target genes. A fundamental question is to understand the molecular mechanisms by which SIRT1 controls the expression of genesinvolved in cell proliferation and energy metabolism. To identify protein partners of SIRT1, we used the method of TAP-TAG purification from a soluble nuclear fraction and a chromatin anchored fraction of Mef cells stably expressing ectopic copy of SIRT1 (SIRT1-e). We were able to identify a SIRT1 complex associated with both cell proliferation factor Ki67, and TFIIIC,subunit required for assembly of the RNA polymerase III pre-initiation complex. By deleting Sirt1, and by specifically inhibiting Ki67 expression, we showed that the RNA Polymerase III transcription machinery and cell proliferation were strongly affected. All of my results clearly shows that SIRT1, Ki67, and TFIIIC are within a same protein complex, SIRT1 and Ki67, acting in coordination to regulate the expression level of SINES and LINES, transcribed from RNA polymerase III transcription machinery.

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