ICB - Instituto de Ciências Biológicas

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2151

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Expressão dos antígenos ABH e Lewis na gastrite crônica e alterações pré- neoplásica da mucosa gástrica
(2002-12) AGUIAR, Délia Cristina Figueira; CORVELO, Tereza Cristina de Oliveira; ARAÚJO, Marialva Tereza Ferreira de; CRUZ, Ermelinda do Rosário Moutinho da; DAIBES, Samiry; ASSUMPÇÃO, Mônica Baraúna de
BACKGROUND:The major cause for chronic gastritis in human is the infection by the Helicobacter pylori. The blood group antigens present at the gastric mucous are described as possible receptor for this bacteria in the epithelium. The alterations in the expression of blood group patterns are associated with the development of gastric cancer. OBJECTIVES: Verify the H. pylori prevalence and examine the immunohistochemical distribution of the ABH and Lewis antigens expression to correlate with histopathological alterations. PATIENTS AND METHODS: From 63 chronic gastritis patients were investigated gastric biopsies, blood and saliva samples by dot-blot-ELISA, indirect immunoperoxidase and hematoxylin-eosin and Gram. RESULTS: No significant association between the presence of the bacteria and the ABH, Lewis and Secretor phenotype was found. For the majority of the patients the antigen expression of the ABH and Lewis blood group was restricted mainly to the foveola epithelium of the gastric mucosa, similar to the saliva. The inappropriate expression of these antigens occurred always in the presence of H. pylori and/or preneoplastic alterations of the gastric mucosa. In areas with intestinal metaplasias we also observed reduced reactivity for the H and Leb antigens and mainly the induced expression of Lea. CONCLUSION: Alterations in the pattern of the glycosylation of this antigens are interesting, because they reflect different stages in the cellular differentiation and become potential markers in the diagnostic evaluation and prognosis of gastric pathologies.
Acesso aberto (Open Access)
Immunodetection of Helicobacter sp. and the associated expression of ABO blood group antigens in the gastric mucosa of captive and free-living New World primates in the Amazon region
(2011-12) AGUIAR, Délia Cristina Figueira; BARROS, Vera Lúcia Reis Souza de; PEREIRA, Washington Luiz Assunção; LOIOLA, Rosane do Socorro Pompeu de; MATOS, Gyselly de Cássia Bastos de; VALSECCHI, João; CORVELO, Tereza Cristina de Oliveira
The histo-blood group ABH antigens were first described in humans. These antigens are only present on erythrocytes from great apes and humans, while in more primitive animals they are found in tissues and body fluids. The ABH antigens are mainly distributed in tissues exposed to the external environment and potentially serve as ligands for pathogens or inhibitors of tissue connections. The objective of this paper was two-fold: (i) to determine the presence of Helicobacter sp. in the gastric mucosa of 16 captive and 24 free-living New World monkeys and (ii) to evaluate the presence of histopathological alterations related to bacterial infection and the associated expression of ABH antigens in the tissue. Stomach tissues from 13 species of monkey were assessed using haematoxylin-eosin and modified Gram staining (Hucker) methods. An immunohistochemical analysis of the tissue revealed the presence of infectious bacteria that were characteristic of the genus Helicobacter sp. The results demonstrate that various species of monkey might be naturally infected with the Helicobacter sp. and that there is an increased susceptibility to infection. This study serves as a comparative analysis of infection between human and non-human primates and indicates the presence of a new species of Helicobacter.
Acesso aberto (Open Access)
The expression of ABH and Lewis antigens in Brazilian semi-isolated Black communities
(2002) CORVELO, Tereza Cristina de Oliveira; AGUIAR, Délia Cristina Figueira; SAGICA, Fernanda do Espírito Santo
The expression of the ABH and Lewis blood groups was determined in blood and saliva samples from two semi-isolated Black communities of Northern Brazil: Cametá and Alcântara. The distributions of ABO blood group phenotypes and the ABH secretor status frequencies showed no significant differences between these populations. In contrast, there was a difference regarding the frequency of the red blood cell Le(a-b-) phenotypes, associated with erythrocyte/saliva discordance, as confirmed by the observation that individuals with Le(a-b-) red cells have the Lewis antigen in their saliva, resulting in a nongenuine Le(a-b-) phenotype, whose frequency was higher in Alcântara.

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