2013-03-072013-03-072012-12-13FERRAZ, Jefferson José Sodré. Prevalência e associação da infecção por Helicobacter pylori e do vírus de Epstein-Barr em adenocarcinoma gástrico, em uma população do norte do Brasil. 2012. 85 f. Tese (Doutorado) - Universidade Federal do Pará, Instituto de Ciências Biológicas, Belém, 2012. Programa de Pós-Graduação em Neurociências e Biologia Celular.https://repositorio.ufpa.br/handle/2011/3524Gastric neoplasias are the second leading cause of cancer-related deaths and although discoveries over physio-pathology of tumour cells, cancer is considered, to the best of our knowledge, minimally controlled by modern medicine. Gastric carcinoma is among the few malignant neoplasms in which infectious agents play an important role. The aim of the present work was to research the prevalence and the association of Helicobacter pylori and Epstein-Barr virus infection in gastric adenocarcinoma in a northern population of Brazil. A hundred twenty-five samples of gastric adenocarcinoma were analyzed by PCR to detect H. pylori and pathogenic genotype H. pylori-cagA+, by in situ hybridization to detect EBV, and by histopathological analysis to determine epidemiologic and clinico-pathological data. It was observed a higher frequency in male patients (68%) as much as older patients (78%). Prevalence to H. pylori was 88%, and it was considered high when compared to early studies in northern region of Brasil. To EBV the prevalence was 9,6%. Patients H. pylori-cagA+ showed increased relative risk to intestinal type adenocarcinoma. The case’s frequency to III and IV stages of the disease was 82,4%, demonstrating that the diagnostic to this neoplasia has been done late. The urease positive cases presented a higher than four-fold relative risk (OR=4,231) to H. pylori-cagA+, the more pathogenic genotype. There wasn’t statistical significance to the association between H. pylori and EBV in the studied population; however the EBV positive cases showed 100% positivity to H. pylori suggesting a possible synergistic relation of these agents in gastric carcinogenesis.porAcesso AbertoAdenocarcinoma gástrico humanoNeoplasias gástricasInfecções por HelicobacterInfecções por vírus Epstein-BarrTeseCNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA