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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.
941

Makrofager som stimulerats med Cutibacterium acnes ökar sitt uttryck av CCL22 mRNA / Macrophages stimulated with Cutibacterium acnes increases its expression of CCL22 mRNA

Lundell, Sandra January 2019 (has links)
Prostatacancer är en av världens vanligaste cancerformer. Varje år diagnostiseras ungefär 1,3 miljoner män världen över med prostatacancer och trots det vet man inte de bakomliggande orsakerna. Det finns flera studier som visar att det finns en koppling mellan infektion och olika typer av cancer och Cutibacterium acnes återfinns i hög utsträckning i prostatacancervävnad. Det har därför föreslagits att det finns ett samband mellan infektion av C. acnes och prostatacancer. Närvaro av tumörassocierade makrofager har visats sig vara gynnande för olika typer av cancer och från dessa makrofager frisätts kemokiner, bland annat CCL22. CCL22 kan vara inblandad i en lokal hämning av immunförsvaret som ofta förknippas med tillväxt av cancer. I detta arbete odlas makrofager från blodgivare med C. acnes för att ta reda på om makrofagerna ökar sitt uttryck av CCL22 mRNA. Genom att analysera resultaten från en kvantitativ realtids-PCR indikeras det att makrofager som behandlats med C. acnes signifikant ökar sitt uttryck av CCL22 mRNA. Sammanfattningsvis bedöms resultaten från detta arbete styrka uppfattningen att det kan finnas en koppling mellan C. acnes och orsakerna bakom prostatacancer men mer arbete återstår för att kunna klargöra dess relevans. / Prostate cancer is one of world´s most common forms of cancer. Every year about 1.3 million men around the world are diagnosed with prostate cancer and even so we cannot fully explain the etiology. There have been several studies indicating that there is a correlation between infection and different forms of cancer. Cutibacterium acnes (C.acnes) can be found to a large extent in prostate cancer tissue and a correlation between infection of C. acnes and prostate cancer has therefore been suggested. The presence of tumor-associated macrophages has been shown to favor various types of cancer. Several chemokines including CCL22 are released from these macrophages. CCL22 may be involved in a local inhibition of the immune system that is often associated with cancer growth. In this work, macrophages from a blood donor are grown with C. acnes to find out if the macrophages increase their expression of CCL22 mRNA after this exposure. By analyzing the results of a quantitative real-time PCR for CCL22 mRNA, it was demonstrated that macrophages treated with C. acnes significantly increase their expression of CCL22 mRNA. In conclusion, the results of this work indicate that there could be a link between C. acnes and the causes of prostate cancer, but more work remains to be able to clarify its relevance.
942

Previsão pré-operatória do estadiamento local do câncer prostático: análise multifatorial baseada em parâmetros clínicos, laboratoriais e de imagem por ressonância magnética e ultra-sonografia / Preoperative prediction of local staging of prostate cancer: multifactorial analysis based on clinical, laboratory and imaging parameters by magnetic resonance and ultrasonography

Daniel Miranda Ferreira 09 August 2005 (has links)
INTRODUÇÃO: O câncer de próstata ocupa o segundo lugar entre as neoplasias de maior incidência na população masculina mundial. Uma vez estabelecido o diagnóstico, o estadiamento passa a ter papel fundamental na escolha da opção e tática terapêuticas. OBJETIVO: Avaliar as diferenças clínicas, laboratoriais e anatomopatológicas dos pacientes e determinar a acurácia, a sensibilidade, a especificidade e os valores preditivos positivo e negativo de vários exames pré-operatórios, avaliando isoladamente e em conjunto aqueles capazes de melhor prever o estadiamento local do câncer prostático. MÉTODOS: Foram analisados o antígeno prostático específico (PSA), as densidades de PSA calculadas pelos exames de ressonância magnética e ultra-som (DPSA), a graduação de Gleason, o número de sextantes positivos e a porcentagem de fragmentos positivos nas biópsias, as probabilidades de doença intraprostática, doença extracapsular e comprometimento das vesículas seminais segundo os nomogramas de Kattan e Partin, e os resultados dos exames de toque retal, da ressonância magnética com bobina endorretal e do ultra-som com Doppler de amplitude em relação ao estadiamento do câncer de próstata em 49 pacientes submetidos à prostatectomia radical. Os resultados foram comparados com os resultados anatomopatológicos. RESULTADOS: Dos 49 pacientes com tumores classificados clinicamente como intraprostáticos, respectivamente 59,2 %, 51,0 % e 32,7 % dos pacientes foram subestadiados clinicamente em relação à doença extraprostática, doença extracapsular e comprometimento das vesículas seminais. Estadiamentos clínicos iniciais tiveram taxas de subestadiamento menores e estadiamentos clínicos mais avançados tiveram taxas de subestadiamento maiores. As médias da maioria dos parâmetros clínicos e laboratoriais dos pacientes com doença avançada apresentaram valores maiores do que as médias dos pacientes com doença localizada. A biópsia prostática superestimou a graduação histopatológica final de Gleason em 10,2 % dos casos, subestimou a graduação em 49,0 % dos casos e a correlação foi idêntica em 40,8 %. A ressonância magnética, quando comparada aos outros parâmetros analisados de forma isolada, apresentou os maiores valores de acurácia na discriminação doença intraprostática x doença extraprostática (73,5 %), doença intracapsular x doença extracapsular (81,6 %) e comprometimento ou não das vesículas seminais (77,6 %). A acurácia geral dos modelos de regressão logística baseada nas variáveis contempladas foi de 71,4 % na previsão de doença extraprostática, 87,2 % na previsão de doença extracapsular e 81,0 % na previsão de comprometimento das vesículas seminais. CONCLUSÃO: A ressonância magnética com bobina endorretal se mostrou ser um dos melhores métodos para o estadiamento local do câncer de próstata e pode ser considerada no estudo de pacientes selecionados / INTRODUCTION: The prostate cancer is the second more frequent neoplasia in the worldwide male population. Since the diagnosis is established, the staging has a fundamental role on the choice of therapeutic option and tactics. OBJECTIVE: To evaluate the clinical, laboratory and anatomopathological differences of patients and determine the accuracy, sensitiveness, specificity and positive and negative predictive values of several preoperative examinations, by evaluating individually and conjointly those which are able to better predict the local staging of prostate cancer. METHODS: The prostate-specific antigen (PSA) was analyzed as well as the PSA densities (PSAD) were calculated through the magnetic resonance and ultrasound, the Gleason\'s grading, the number of positive sextants and the percentage of positive fragments in biopsies, the probabilities of intraprostatic disease, extracapsular disease and involvement of seminal vesicles according to Kattan and Partin\'s nomograms, and the results of rectal palpations, the use of endorectal coil magnetic resonance imaging and the use of amplitude Doppler ultrasound in relation to the staging of prostate cancer in 49 patients who were submitted to radical prostatectomy. The results were compared with the anatomopathological results. RESULTS: Among 49 patients with tumors clinically classified as intraprostatic, 59.2%, 51.0% and 32.7% patients respectively were clinically understaged in relation to extraprostatic disease, extracapsular disease and involvement of seminal vesicles. The initial clinical staging had lower substaging rates and the more advanced clinical staging had higher substaging rates. The averages of most clinical and laboratory parameters of patients with advanced disease presented values higher than the averages of patients with localized disease. The prostatic biopsy overestimated the Gleason\'s final histopathologic grade in 10.2% of cases, underestimated the grade in 49.0 % of cases and had identical correlation in 40.8%. The magnetic resonance imaging, when compared with all of other parameters analyzed isolately, presented the highest accuracy values in the discrimination intraprostatic disease x extraprostatic disease (73.5%), intracapsular disease x extracapsular disease (81.6 %) and the presence of seminal vesicles involvement (77.6%). The general accuracy of logistic regression models based on contemplated variables was of 71.4% in the extraprostatic disease prediction, 87.2% in the extracapsular disease prediction and 81.0% in the prediction of involvement of seminal vesicles. CONCLUSION: The use of endorectal coil magnetic resonance imaging was one of the best predictors of local staging of prostate cancer and could be considered in the study of selected patients
943

ASSOCIAÇÃO ENTRE PESO PROSTÁTICO E SCORE DE GLEASON EM PACIENTES PORTADORES DE CÂNCER DE PRÓSTATA SUBMETIDOS A PROSTATECTOMIA RADICAL.

Bezerra, Leandro Ferro de Moraes 14 March 2014 (has links)
Made available in DSpace on 2016-08-10T10:54:22Z (GMT). No. of bitstreams: 1 LEANDRO FERRO DE MORES BEZERRA.pdf: 1240257 bytes, checksum: a30f985e8e1e6335c0962e3a513026fc (MD5) Previous issue date: 2014-03-14 / Introduction: Prostate cancer is one of he most frequent cancer types among men around the world and its global incidence has dramatically arrised on last decade. The prognostic factors already known are: Seric Prostatic Specific Antigen (PSA), Gleason Score and Clinical Stage. The prostate gland volume may be associated with these factors. Objecives: Evaluate a possible association between protate gland volume and the presence of high Gleason Score (7 or higher) on individuals with prostate cancer. Methods: We analyzed data from 139 files of patients who underwent radical prostatectomy for prostate cancer between march 2009 and november 2012. Prostate weight measured at prostatectomy was compared to other clinical variables (age, prostate specific antigen, PSA density) and pathological outcomes (final Gleason score, pathological stage). Patients were divided in 3 groups due to its prostate size (under 50grams, between 50-80grams and over 80grams). Multivariate logistic regression was used to assess prostate size as a predictor of high grade prostate cancer. RESULTS: The study population included 139 patients during march 2009 to november 2012, of whom 64 (46,04%) had Gleason Score 7 or higher. No association between low prostate weight and hight grade gleason score was found. This event were more frequent on intermediate group (prostate weight between 50 and 80 grams). We also did not find any association between prostate weight and any of the others paramters analysed between the 3 groups. Conclusions: No association between prostate size and hight grade Gleason score was found. Association between prostate size and any of the others paramters analysed between the 3 groups was not found either. / Introdução: O câncer de próstata é um dos cânceres mais frequentes entre homens no mundo e sua incidência global tem aumentado dramaticamente na última década. Os fatores prognósticos já conhecidos são: valores séricos do antígeno prostático específico (PSA), grau de diferenciação histológica (Score de Gleason) e estádio clínico. O peso da glândula prostática pode estar associado a estes fatores. Objetivo: Avaliar a possível associação entre volume da glândula prostática e a presença de perfil histológico desfavorável (Score de Gleason 7 ou acima) em sujeitos portadores de câncer de próstata. Material e Métodos: Foram analisados dados de 139 prontuários de indivíduos portadores de câncer de próstata submetidos a prostatectomia radical entre março de 2009 e dezembro de 2012. O tamanho prostático foi medido através da aferição de peso do espécime cirúrgico e foi comparado às outras variáveis clínicas (idade, PSA, densidade de PSA) e dados anátomo-patológicos (Score de Gleason e estádio patológico). Os casos foram separados em 3 grupos, relacionados ao peso prostático (abaixo de 50 gramas, entre 50 e 80 gramas e acima de 80 gramas). Análise multivariada foi usada para avaliar a associação entre o peso prostático e o tumor prostático de alto grau. Resultados: A população estudada incluiu 139 sujeitos submetidos a prostatectomia radical entre março de 2009 e novembro de 2012. Destes, 64 (46,04%) apresentavam Score de Gleason maior ou igual a 7. Não houve associação significativa entre baixo peso prostático (abaixo de 50 gramas) a presença de Score de Gleason de alto grau. Tal evento foi mais frequente no grupo com próstatas com peso entre 50 e 80 gramas. Também não foi evidenciado associação entre baixo volume prostático e demais fatores avaliados. Conclusão: Não foi encontrado associação entre baixo volume prostático e presença de Score de Gleason de alto grau assim como com os demais parâmetros avaliados.
944

Desenvolvimento e validação de nomogramas para estimativa de risco para câncer de próstata em população brasileira / Development and validation of a nomogram to estimate risk for prostate cancer in the Brazilian population

Silva, Thiago Buosi 12 April 2013 (has links)
INTRODUÇÃO: O câncer de próstata é a segunda causa de morte relacionada ao câncer nos Estados Unidos e no Brasil. Sua incidência tem aumentado significativamente após a década de 90 devido a implantação de programas de rastreamento pelo PSA, que embora seja considerado um método sensível para identificar os pacientes com risco para o câncer de próstata, sua especificidade é considerada baixa. O objetivo foi desenvolver e validar nomogramas para estimar a probabilidade de câncer de próstata e câncer de próstata indolente em pacientes submetidos a um rastreamento oportunístico. MÉTODOS: Trata-se de um estudo observacional transversal baseado em uma coorte de pacientes atendidos pela Unidade Móvel de Prevenção e biopsiados no Departamento de Radiologia do Hospital de Câncer de Barretos entre janeiro de 2004 e dezembro de 2007. Os dados clínicos e patológicos foram coletados dos prontuários dos pacientes, seguindo uma ficha de coleta padronizada previamente elaborada e digitada em banco de dados no Software IBM® SPSS® Statistics 20.0.1 for Windows para posterior análise. Análises de regressão logística binária foram realizadas para avaliar o modo como cada um dos fatores em combinação permitiria supor a presença de câncer de próstata. RESULTADOS: Dos 1.639 pacientes que foram encaminhados para o Hospital de Câncer de Barretos para a realização da biópsia prostática, 553 (42,1%) tiveram confirmação histopatológica de adenocarcinoma prostático. Os tumores indolentes foram encontrados em 66 (5,0%) dos casos positivos. As análises de regressão logística forneceram uma área sob a curva ROC de 0,737 (IC 95% = 0,678 a 0,796) para predição do câncer de próstata e de 0,696 (IC 95% = 0,591 a 0,802) para predição de câncer de próstata indolente. CONCLUSÃO: Os modelos construídos apresentaram poder de predição razoável considerando-se os eventos estudados / BACKGROUND: Prostate cancer is the second leading cause of cancerrelated death in the United States and in Brazil. Its incidence has increased significantly after the 90\'s due to the implementation of PSA screening programs, despite being considered a sensitive method to identify patients at risk of prostate cancer, its specificity is considered low. The aim was to develop and validate nomograms to estimate the probability of prostate cancer and indolent prostate cancer in patients undergoing opportunistic screening. METHODS: This was a cross sectional observational study based on a cohort of patients seen at the Prevention Mobile Unit and biopsied in the Radiology Department of the Barretos Cancer Hospital between January 2004 and December 2007. The clinical and pathological data were collected from patient charts, following a standardized collection form previously completed and entered into the database in IBM® SPSS® Software Statistics 20.0.1 for Windows for further analysis. Binary logistic regression analyses were performed in order to assess how each factor in combination would predict the presence of prostate cancer. RESULTS: Out of the 1,639 patients who were referred to the Barretos Cancer Hospital for prostate biopsy, 553 (42.1%) had histopathological confirmation of prostatic adenocarcinoma. Indolent tumors were found in 66 (5.0%) of the positive cases. The logistic regression analyses provided an area under the ROC curve of 0.737 (95% CI = 0.678 to 0.796) for prediction of prostate cancer and 0.696 (95% CI = 0.591 to 0.802) for the prediction of indolent prostate cancer. CONCLUSION: The constructed models showed a reasonable predictive power, considering the events studied
945

Previsão pré-operatória do estadiamento local do câncer prostático: análise multifatorial baseada em parâmetros clínicos, laboratoriais e de imagem por ressonância magnética e ultra-sonografia / Preoperative prediction of local staging of prostate cancer: multifactorial analysis based on clinical, laboratory and imaging parameters by magnetic resonance and ultrasonography

Ferreira, Daniel Miranda 09 August 2005 (has links)
INTRODUÇÃO: O câncer de próstata ocupa o segundo lugar entre as neoplasias de maior incidência na população masculina mundial. Uma vez estabelecido o diagnóstico, o estadiamento passa a ter papel fundamental na escolha da opção e tática terapêuticas. OBJETIVO: Avaliar as diferenças clínicas, laboratoriais e anatomopatológicas dos pacientes e determinar a acurácia, a sensibilidade, a especificidade e os valores preditivos positivo e negativo de vários exames pré-operatórios, avaliando isoladamente e em conjunto aqueles capazes de melhor prever o estadiamento local do câncer prostático. MÉTODOS: Foram analisados o antígeno prostático específico (PSA), as densidades de PSA calculadas pelos exames de ressonância magnética e ultra-som (DPSA), a graduação de Gleason, o número de sextantes positivos e a porcentagem de fragmentos positivos nas biópsias, as probabilidades de doença intraprostática, doença extracapsular e comprometimento das vesículas seminais segundo os nomogramas de Kattan e Partin, e os resultados dos exames de toque retal, da ressonância magnética com bobina endorretal e do ultra-som com Doppler de amplitude em relação ao estadiamento do câncer de próstata em 49 pacientes submetidos à prostatectomia radical. Os resultados foram comparados com os resultados anatomopatológicos. RESULTADOS: Dos 49 pacientes com tumores classificados clinicamente como intraprostáticos, respectivamente 59,2 %, 51,0 % e 32,7 % dos pacientes foram subestadiados clinicamente em relação à doença extraprostática, doença extracapsular e comprometimento das vesículas seminais. Estadiamentos clínicos iniciais tiveram taxas de subestadiamento menores e estadiamentos clínicos mais avançados tiveram taxas de subestadiamento maiores. As médias da maioria dos parâmetros clínicos e laboratoriais dos pacientes com doença avançada apresentaram valores maiores do que as médias dos pacientes com doença localizada. A biópsia prostática superestimou a graduação histopatológica final de Gleason em 10,2 % dos casos, subestimou a graduação em 49,0 % dos casos e a correlação foi idêntica em 40,8 %. A ressonância magnética, quando comparada aos outros parâmetros analisados de forma isolada, apresentou os maiores valores de acurácia na discriminação doença intraprostática x doença extraprostática (73,5 %), doença intracapsular x doença extracapsular (81,6 %) e comprometimento ou não das vesículas seminais (77,6 %). A acurácia geral dos modelos de regressão logística baseada nas variáveis contempladas foi de 71,4 % na previsão de doença extraprostática, 87,2 % na previsão de doença extracapsular e 81,0 % na previsão de comprometimento das vesículas seminais. CONCLUSÃO: A ressonância magnética com bobina endorretal se mostrou ser um dos melhores métodos para o estadiamento local do câncer de próstata e pode ser considerada no estudo de pacientes selecionados / INTRODUCTION: The prostate cancer is the second more frequent neoplasia in the worldwide male population. Since the diagnosis is established, the staging has a fundamental role on the choice of therapeutic option and tactics. OBJECTIVE: To evaluate the clinical, laboratory and anatomopathological differences of patients and determine the accuracy, sensitiveness, specificity and positive and negative predictive values of several preoperative examinations, by evaluating individually and conjointly those which are able to better predict the local staging of prostate cancer. METHODS: The prostate-specific antigen (PSA) was analyzed as well as the PSA densities (PSAD) were calculated through the magnetic resonance and ultrasound, the Gleason\'s grading, the number of positive sextants and the percentage of positive fragments in biopsies, the probabilities of intraprostatic disease, extracapsular disease and involvement of seminal vesicles according to Kattan and Partin\'s nomograms, and the results of rectal palpations, the use of endorectal coil magnetic resonance imaging and the use of amplitude Doppler ultrasound in relation to the staging of prostate cancer in 49 patients who were submitted to radical prostatectomy. The results were compared with the anatomopathological results. RESULTS: Among 49 patients with tumors clinically classified as intraprostatic, 59.2%, 51.0% and 32.7% patients respectively were clinically understaged in relation to extraprostatic disease, extracapsular disease and involvement of seminal vesicles. The initial clinical staging had lower substaging rates and the more advanced clinical staging had higher substaging rates. The averages of most clinical and laboratory parameters of patients with advanced disease presented values higher than the averages of patients with localized disease. The prostatic biopsy overestimated the Gleason\'s final histopathologic grade in 10.2% of cases, underestimated the grade in 49.0 % of cases and had identical correlation in 40.8%. The magnetic resonance imaging, when compared with all of other parameters analyzed isolately, presented the highest accuracy values in the discrimination intraprostatic disease x extraprostatic disease (73.5%), intracapsular disease x extracapsular disease (81.6 %) and the presence of seminal vesicles involvement (77.6%). The general accuracy of logistic regression models based on contemplated variables was of 71.4% in the extraprostatic disease prediction, 87.2% in the extracapsular disease prediction and 81.0% in the prediction of involvement of seminal vesicles. CONCLUSION: The use of endorectal coil magnetic resonance imaging was one of the best predictors of local staging of prostate cancer and could be considered in the study of selected patients
946

Discriminación entre hiperplasia prostática benigna y cáncer de próstata mediante el uso de PSA index en consulta externa de urología / Discrimination between benign prostatic hyperplasia and prostate cancer by means of PSA index in urology outpatient consult

Pinedo Pichilingue, Aranza, San Martín-San Martín, Gustavo, Carreazo, Nilton Yhuri 01 1900 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Objetivo El antígeno prostático específico es utilizado en el diagnóstico de patologías prostáticas. No existe un estudio en Perú que proponga un punto de corte de PSA index para discriminar entre cáncer de próstata e hiperplasia prostática benigna para la indicación de biopsia prostática. Actualmente, se emplean diferentes puntos de corte basados en estudios internacionales. Material y métodos Se realizó un estudio de validación diagnóstica de PSA index para discriminar entre ambas entidades en pacientes con un PSA total entre 4,0 ng/ml y 9,9 ng/ml. Fueron incluidos 356 pacientes con diagnóstico de hiperplasia prostática benigna o cáncer de próstata mediante biopsia prostática. Se evaluó la sensibilidad, especificidad, los valores predictivos y los cocientes de probabilidad de los valores de PSA index de 15 hasta 25%. Se graficó la curva ROC. Resultados Un PSA index de 17% posee mejores valores de sensibilidad (87,8%), especificidad (62,2%) y valores predictivos (valor predictivo positivo de 62,4% y valor predictivo negativo de 87,4%) respecto a otros para disminuir el número de biopsias negativas. El cociente de probabilidad positivo fue 2,3 y el cociente de probabilidad negativo fue 0,1. El área bajo la curva fue 0,75 [IC 95%, 0,71 a 0,79]. Conclusión Se sugiere un PSA index de 17% como punto de corte para discriminar entre hiperplasia prostática benigna y cáncer de próstata en pacientes que acuden a consulta ambulatoria con un PSA total entre 4,0 ng/ml y 9,9 ng/ml. Se recomienda este valor si se desea reducir el número de biopsias prostáticas negativas. / Revisión por pares
947

L'effet anticancéreux d'un sélénium : étude de son rôle dans l'activité de réparation de l'ADN et la résistance au stress oxydant / The anticancer effect of selenium : study of its role in DNA repair activity and resistance to oxidative stress

De Rosa, Viviana 13 October 2011 (has links)
Le sélénium est reconnu comme un micronutriment important pour l'homme et les animaux. Plusieurs études ont montré qu'une supplementation en sélénium dans le régime alimentaire pourrait être bénéfique contre les cancers du foie, du colon, du pancréas et de la prostate. Le mécanisme anti-carcinogène du sélénium se produit au niveau systémique, cellulaire et nucléaire. Ces processus peuvent également impliquer le système immunitaire et ne doivent pas être interprétés par un seul mécanisme. Jusqu'à présent son mécanisme d'action est encore inconnu. L'objectif de cette étude était d'étudier l'effet des composés du sélénium, à faibles concentrations, sur la capacité de réparation de l'ADN dans les cellules du cancer de la prostate LNCaP (p53 compétentes). Ce travail est divisé en trois parties. La première partie du travail a été consacrée à étudier l'effet des deux composés du sélénium (SS et SM) sur les propriétés cytotoxiques et génotoxiques de différents stress oxydatifs et non oxydatifs. Les résultats ont montré qu'un prétraitement avec une faible dose en Se stimulait la synthèse des sélénoprotéines, et protègait contre la toxicité et les dommages oxydatifs à l'ADN induites par les UVA ou H2O2, mais pas par MMS ou UVC. La deuxième partie a été consacrée à l'influence de la supplementation en sélénium sur la capacité de réparation de l'ADN. Notre travail a clairement montré l'augmentation de l'efficacité d'excision de certaines glycosylases que n'est pas nécessairement corrélée à une augmentation de l'expression génique et /ou protéiques. Enfin, la troisième partie de notre travail a été dédiée à l'optimisation de la technique Host Cell Reactivation (HCR) qui nous a permis d'étudier la capacité de réparation de l'ADN in cellulo, afin de cibler les partenaires impliqués dans la voie de signalisation affectées par la supplémentation en sélénium. En conclusion, nous pourront penser que le mécanisme d'action du sélénium est représenté par un délicat équilibre entre l'activation et la répression de l'activité de certaines protéines qui induit des changements conformationnels plus ou moins directement impliqués dans la réparation de l'ADN et la progression de la croissance cellulaire. / Selenium was recognized as an important micronutrient for both humans and animals. Several studies showed that increased selenium in the diet might be beneficial against liver, colon, pancreas and prostate cancer. The anticarcinogenic actions of Se occur at the systemic, cellular and nuclear level. These actions may also involve the immune system and thus cannot be interpreted by a single mechanism. Until now its mechanisms of action are not well understood. The objective of this study was to investigate the effect of selenocompounds at low doses on DNA repair capacity in the p53-proficient LNCaP prostate cancer cells. This work is divided into three parts. The first part of the work was devoted to study the effect of two selenocompounds (SS and SM) on the cytotoxic and genotoxic properties of various oxidative and non oxidative stresses. The results showed that low doses of Se pre-treatment stimulates selenoprotein synthesis, protects against toxicity and oxidative DNA damage induced by UVA or H2O2 but not by MMS or UVC. The second part of our investigation was devoted to the influence of selenium supplementation on DNA repair capacity. Our work clearly showed an increase in excision efficiency of the glycosylases activity that was not necessarily correlated with an increase of gene expression and/or protein levels. Finally, the third part of our work was devoted to the optimization of Host Cell Reactivation assay (HCR) to study the DNA repair capacity in cellulo, in order to target the partners involved in the signalling pathway affected by selenium supplementation. In conclusion, we could image that the mechanism of action of selenium is represented by a delicate balance between activation and repression of protein activity that induces conformational changes of several proteins more or less directly involved in DNA repair and progression of cell growth.
948

Cancer de la prostate en Guadeloupe : Facteurs de risque génétique et environnementaux de survenue et de récidive après prostatectomie radicale / Prostate cancer in Guadeloupe : genetic and environmental risk factors of occurrence after radical prostatectomy

Brureau, Laurent 17 December 2015 (has links)
Le cancer de la prostate est la pathologie tumorale la plus fréquente aux Antilles. Notre étude a pour but d’étudier certains facteurs de risque de survenue et de récidive. Pour mener à bien cette étude, nous avons utilisé les patients inclus dans l’étude cas-témoins Karuprostate, et une cohorte de patients après prostatectomie radicale.Les principaux résultats et conclusions de ma thèse portent sur :a) L’étude des facteurs génétiques en lien avec le métabolisme des xénobiotiques dans le risque de survenue du cancer de la prostate en Guadeloupe. Le nombre exact de copies (CNV) des gènes codant pour les Glutathion S transférases GSTM1 et GSTT1 ont été déterminés chez 629 cas incidents de cancer de la prostate et 622 témoins. Les hommes présentant 2, 3 ou plus de copies de GSTT1 présentent un risque significativement augmenté de cancer de la prostate. De même les hommes avec 3, 4, 5 ou plus de copies combinant GSTM1 et GSTT1 présentent un risqué augmenté de survenue de la maladie.b) L’étude des facteurs génétiques en lien avec le métabolisme des œstrogènes dans le risque de survenue du cancer de la prostate en Guadeloupe. Cinq polymorphismes (3 SNP concernant CYP17, CYP1B1 et COMT, ainsi que de polymorphismes de taille concernant CYP19 et UGT1A1) ont été étudiés et comparés chez 498 cas incidents et 565 témoins. Les sujets présentant le génotype AA de COMT présentent un risque significativement diminué de survenue du cancer la prostate. Aucune association significative n’a été retrouvée avec les autres polymorphismes étudiés. Une étude portant sur 150 cas incidents de cancer de la prostate et 150 témoins issus d’une population du Congo-Zaïre a fait l’objet de ces mêmes génotypages avec les mêmes résultats.c) L’influence des expositions environnementales à des polluants persistants présentant des propriétés hormonales sur la récidive biologique de cancer de la prostate après prostatectomie radicale. Les concentrations plasmatiques en chlordécone, DDE (principal métabolite du DDT) et en PCBs ont été mesurés chez 340 sujets porteurs d’un cancer de la prostate ayant subi une prostatectomie radicale. L’exposition (préopératoire) au chlordécone a été retrouvée associé à une augmentation significative du risque de récidive biologique. A l’inverse, les concentrations croissantes en DDE ont été retrouvées associées à une diminution significative du risque de récidive biologique. Aucune association n’a été retrouvée entre l’exposition au PCB153 et la récidive de la maladie.d) Les facteurs de risque de récidive de cancer de la prostate clinique et histologique ont été étudiés sur 964 patients qui ont bénéficié d’une prostatectomie radicale avec un suivi média de 4,8 ans. Le diabète, le PSA, le stade clinique avancé, le score de Gleason élevé, un pourcentage de biopsie de prostate élevé, le stade pathologique avancé, la présence de marge positive sont des facteurs prédictifs de récidive biologique après prostatectomie radicale. Nos résultats montrent que la survenue et la récidive du cancer de la prostate sont sous l’influence des facteurs génétiques et environnementaux. Le contexte génétique et environnemental spécifique à la Guadeloupe expliquerait en partie la forte incidence du cancer de la prostate.Par ailleurs, d’autres travaux intégreront d’autres gènes dans le futur. Le projet ambitieux à venir est la création d’une cohorte prospective de tous les patients atteints d’un cancer de la prostate tout stade confondu. / Prostate cancer is the most common tumor pathology in West Indies. Our study aims to study risk factors of occurrence and recurrence.To carry out this study, we used the patients included in the case-control study called Karuprostate and a cohort of patients after radical prostatectomy.The main results and conclusions of my work are:a) The study of genetic factors related to the metabolism of xenobiotics and the risk of prostate cancer occurrence in Guadeloupe. The exact number (CNV) gene encoding the glutathione S transferases GSTT1 and GSTM1 were determined in 629 incident cases of prostate cancer and 622 controls. Men having 2, 3 or more copies of GSTT1 have a significantly increased risk of prostate cancer. Similarly men with 3, 4, 5 or more copies of GSTM1 and GSTT1 combined have an increased risk of disease occurrence.b) The study of genetic factors related to estrogen metabolism and the risk of prostate cancer occurrence in Guadeloupe. Five polymorphisms (SNP 3 on CYP17, CYP1B1 and COMT as well as size and UGT1A1 polymorphisms on CYP19) were studied and compared in 498 incident cases and 565 controls. Individuals with the AA genotype COMT have a significantly decreased risk of prostate cancer occurrence. No significant association was found with other studied polymorphisms. A study of 150 incident cases of prostate cancer and 150 controls from a population of Congo-Zaire was the subject of these same genotyping, with the same results.c) The influence of environmental exposure to persistent pollutants with hormonal properties of biochemical recurrence of prostate cancer after radical prostatectomy. The plasma concentrations of chlordecone, DDE (the main metabolite of DDT) and PCBs were measured in 340 subjects with prostate cancer who underwent radical prostatectomy. The exhibition (preoperative) to chlordecone was found associated with a significant increased risk of biochemical recurrence. Conversely, the increasing concentrations of DDE were found associated with a significantly decreased risk of biochemical recurrence. No association was found between exposure to PCB153 and recurrence of the disease.d) The clinical and histological risk factors of recurrence of prostate cancer were studied in 964 patients who underwent radical prostatectomy with a médian follow-up of 4.8 years. Diabetes, PSA, advanced clinical stage, high Gleason score, a high percentage of prostate biopsy, advanced pathological stage, the presence of positive margins are predictors of biochemical recurrence after radical prostatectomy.Our results show that the occurrence and recurrence of prostate cancer are Under influence of genetic and environmental factors. The specific genetic and environmental context in Guadeloupe may partly explain the high incidence of prostate cancer.In addition, further work will incorporate other genes in the future. The next ambitious project is the creation of a prospective cohort of all patients with all prostate cancer stages.
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Étude du transcriptome des rétrovirus endogènes humains et implications fonctionnelles : applications à la recherche de marqueurs diagnostiques de cancers / Study of the transcriptome of human endogenous retroviruses and functional implications : applications to the search for diagnostic markers of cancers

Perot, Philippe 29 November 2012 (has links)
Le génome humain contient environ 200 000 séquences d'origine rétrovirale (HERV), intégrées au fil de l'évolution et organisées aujourd'hui en familles multicopies complexes globalement réprimées par un contrôle épigénétique. L'étude du transcriptome HERV au niveau locus est compliquée par les similarités phylogénétiques au sein d'une famille et par la profusion des sites d'intégration, deux propriétés inhérentes aux éléments transposables. Dans ce travail, nous avons utilisé une méthode de conception de sondes de détection de 25 mer afin d'adresser la question de l'expression individuelle des HERV. Une puce à ADN haute densité intégrant plus de 5 500 séquences HERV et permettant une lecture fonctionnelle de l'activité de leurs LTRs a été utilisée sur un panel de tissus sains et cancéreux. Cela a permis d'identifier 1 718 séquences HERV actives, dont 326 LTRs promotrices et 209 LTRs polyA. L’étude de l’environnement génomique a mis en évidence une fenêtre d’environ 8 kb en amont des LTRs promotrices, caractérisée par une sous-représentation en gènes cellulaires en orientation sens. Nous avons également montré que le transcriptome des rétrovirus endogènes humains suit des règles de tropisme d’expression, qu’il est sensible aux états de différenciation cellulaire et qu’il ne semble pas être corrélé à l’âge des familles. Une première tentative d’exploitation de ce répertoire HERV dans un contexte clinique a visé à rechercher de nouveaux marqueurs diagnostiques du cancer de la prostate à partir de prélèvements urinaires, par la réalisation d’une étude pilote sur 45 patients / The human genome contains around 200,000 endogenous retroviral sequences (HERV) integrated during the evolution and which are nowadays organized into complex multicopy families, globally repressed by epigenetic control. The study of the HERV transcriptome at the locus level is complicated by phylogenetic similarities within one family and by the profusion of integration sites, two inherent characteristics of transposable elements. In this work, we used a method aiming to optimally characterize individual loci associated with 25 mer probes. A custom microarray dedicated to more than 5,500 HERV sequences and allowing a functional interpretation of the LTRs expression was used on a panel of normal and tumor tissues. We therefore identified 1,718 active HERV sequences, including 326 promoter LTRs and 209 polyA LTRs. The study of the genomic environment has highlighted an approximately 8 kb zone upstream of promoter LTRs characterized by a drastic reduction in sense cellular genes. We also showed that the HERV transcriptome follows tropism rules, is sensitive to the state of cell differentiation and, unexpectedly, seems not to correlate with the age of the families. In a first attempt to use the HERV repertoire in clinical, we sought to identify new markers of prostate cancer from urine samples. This goal was pursued by conducting a pilot study on 45 patients
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Pesquisa de tecido prostático em pacientes 46,XX portadoras da forma clássica de hiperplasia congênita das supra-renais / Search of prostatic tissue in 46,XX congenital adrenal hyperplasia patients

Mariana da Costa Rose Paulino 18 June 2007 (has links)
Introdução: A presença de tecido prostático em pacientes 46,XX portadoras de hiperplasia congênita das supra-renais (HCSR) já foi relatada por alguns autores. Acredita-se que o desenvolvimento deste tecido decorre do estímulo androgênico, através da dihidrotestosterona, sobre as glândulas parauretrais de Skene destas pacientes. Estas glândulas, presentes em todas as meninas, possuem homologia histológica e enzimática com a próstata masculina. Além da presença de tecido prostático nestas pacientes, houve dois relatos de alterações neste tecido, sendo o primeiro o de uma paciente 46,XX portadora de deficiência de 21-hidroxilase, que desenvolveu uma hiperplasia benigna prostática e outra com a mesma deficiência enzimática que aos 62 anos apresentou adenocarcinoma de próstata. Objetivos: 1. Verificar a ocorrência de tecido prostático nas pacientes acima de 6 anos, portadoras da forma clássica de hiperplasia congênita das supra-renais, com cariótipo 46,XX, em acompanhamento no ambulatório de endocrinologia pediátrica do Instituto da Criança; 2. Analisar a sensibilidade e especificidade do antígeno prostático específico (PSA) e da dihidrotestosterona das pacientes com HCSR em relação à detecção do tecido prostático através da ressonância nuclear magnética da região pélvica; 3. Correlacionar os níveis de PSA com os níveis de testosterona e dihidrotestosterona das pacientes portadoras de HCSR. Casuística: Constituiu-se de 32 pacientes 46,XX portadoras da forma clássica de hiperplasia congênita das suprarenais (31 com deficiência de 21-hidroxilase e uma com deficiência de 11- hidroxilase), com uma média de idade de 11,8 +/- 4,2 anos e um grupo controle que incluiu 10 meninas e 10 meninos sem hiperplasia congênita das supra-renais, com média de idade de 9,8 +/- 1,9 anos e 9,3 +/- 2,7 anos respectivamente. Os pacientes do grupo controle faziam acompanhamento no ambulatório de endocrinologia pediátrica por baixa estatura ou puberdade precoce. Métodos: O padrão-ouro utilizado para a detecção de tecido prostático foi a ressonância magnética de região pélvica, que foi realizada em todos os pacientes. Também foram dosados o antígeno prostático específico, a 17-hidroxiprogesterona, o 21-desoxicortisol, o 11- desoxicortisol, a androstenediona, a testosterona e a dihidrotestosterona. Resultados: A detecção do tecido prostático nas ressonâncias de região pélvica foi obtida em 5 pacientes com hiperplasia congênita das supra-renais. O antígeno prostático específico mostrou uma sensibilidade de 100% e especificidade de 88,9% para um ponto de corte de 0,1 ng/mL. A dihidrotestosterona revelou uma sensibilidade de 100% e especificidade de 60% para um ponto de corte de 27,7 ng/dL. Houve uma correlação positiva entre os níveis de PSA com os níveis de T e entre os níveis de PSA e DHT. Conclusões: A ocorrência de tecido prostático nas pacientes 46,XX portadoras de hiperplasia congênita das supra-renais estudadas foi de 15,6%. O PSA mostrou ser um valioso marcador de tecido prostático nas pacientes com HCSR. De acordo com os achados, a pesquisa de tecido prostático deve ser considerada em todas as pacientes portadoras da forma clássica de HCSR / Introduction: The presence of prostatic tissue in 46,XX congenital adrenal hyperplasia (CAH) patients has already been reported. The development of this tissue is due to androgenic stimulation in Skenes paraurethral glands by dihydrotestosterone. These glands have histological and enzymatic homology with the prostate. So far, two cases with alterations of prostatic tissues have been reported: one 46,XX patient with 21-hydroxylase deficiency developed benign prostatic hyperplasia and another with the same enzymatic deficiency, at age of 62 years, had adenocarcinoma of prostate. Objectives: 1.To describe the presence of prostatic tissue in 46, XX patients with the classical form of congenital adrenal hyperplasia 2. To evaluate the sensitivity and specificity of prostatic specific antigen (PSA) and dihydrotestosterone with regard to the detection of prostatic tissue in pelvic MRI. 3. To correlate prostate specific antigen levels with testosterone and dihydrotestosterone levels in girls with congenital adrenal hyperplasia. Patients and Methods: Among our CAH patients followed at our Unit, we selected 32 children and adolescents 46,XX, from 6 to 22 years of age, with the classical form of congenital adrenal hyperplasia (mean age 11.8 +/- 4.2); 31 patients had 21- hydroxylase deficiency and one 11-hydroxylase deficiency. Control group included 10 boys (mean age 9.3 +/- 2.7) and 10 girls (mean age 9.8 +/- 1.9) without CAH. Pelvic MRI (taken as the “gold standard method”) was performed in all patients to detect prostatic tissue. Prostate specific antigen, 17-hydroxyprogesterone, 21- deoxycortisol, 11-deoxycortisol, androstenedione, testosterone and dihydrotestosterone were measured in all patients. Results: Five congenital adrenal hyperplasia girls showed image of prostatic tissue on pelvic MRI. Prostate specific antigen had sensitivity and specificity of 100.0% and 88.9%, respectively, taking 0.1 ng/mL as the cutoff level. The dihydrotestosterone had a sensitivity and specificity of 100% and 60%, respectively, with a cutoff level of 27.7 ng/dL. There was a positive correlation between PSA levels and testosterone and dihydrotestosterone levels. Conclusions: The incidence of prostatic tissue in 46,XX patients with the classical form of congenital adrenal hyperplasia was 15.6%. PSA demonstrated to be a good marker of prostatic tissue in these patients. Based on this study, we have to be cautious when treating a girl with the classical form of CAH and the search for prostatic tissue must be considered in every patient

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