FAMED – Faculdade de Medicina
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/2422
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9 resultados
Resultados da Pesquisa
- ItemAnálise comparativa entre alvos moleculares para detecção do Helicobacter pylori(2015) Gautério, Thaísa Bozzetti; Ramis, Ivy Bastos; Vianna, Júlia Silveira; Halicki, Priscila Cristina Bartolomeu; Groll, Andrea Von; Silva, Pedro Eduardo Almeida da
- ItemHelicobacter pylori pathogenicity genes, cytokine polymorphisms and environmental factors affect the development of gastric diseases: an overview(2016) Vianna, Júlia Silveira; Silva, Pedro Eduardo Almeida da; Ramis, Ivy BastosJustificativa e Objetivos: Helicobacter pylori é uma bactéria Gram negativa que coloniza o estômago de aproximadamente 50% da população humana mundial. Este microrganismo é o principal agente causal de gastrite e um importante fator de risco para o desenvolvimento deúlcera péptica e carcinoma gástrico. Os fatores que determinam essa diversidade de manifestações clínicas permanecem incertos, mas podem estar relacionados com a interação dos fatores bacterianos, sistema immune do hospedeiro e variáveis ambientais. O objetivo desta revisão é fornecer uma visão geral destes fatores que influenciam na susceptibilidade a desordens severas de infecção por H. pylori. Metodo: Para isso, foram selecionados artigos originais e de revisão através da pesquisa nas bases de dados bibliográficos PubMed, Portal de Periódicos CAPES e SCIELO. Resultados: H. pylori possui um conjunto de fatores de patogenicidade, tais como cagA, vacA, iceA, babA, para colonizar a mucosa gástrica e estabelecer infecção crônica. Estes fatores bacterianos são agentes essenciais em modular a resposta imune envolvida na iniciação da carcinogênesegástrica. Os fatores genéticos do hospedeiro contribuem para regular a resposta inflamatória e para o agravamento da lesão da mucosa gástrica uma vez que a infecção gástrica por H. pylori induz a produção de várias citocinas pró e anti-inflamatórias no hospedeiro. O papel prejudicial dos fatores ambientais está relacionado com as precárias condições socioeconômicas, com o consumo de sal, com o tabagismo e com o consumo de álcool. Conclusão: Ao decifrar as regras deterministas - se houver - dessa interação entre fatores da bactéria, do hospedeiro e variáveis ambientais, será possível prever, tratar e, finalmente, prevenir graves doenças gastroduodenais.
- ItemDetection of helicobacter pylori CagA EPIYA in gastric biopsy specimens and its relation to gastric diseases(2015) Vianna, Júlia Silveira; Ramis, Ivy Bastos; Halicki, Priscila Cristina Bartolomeu; Gastal, Otavio Leite; Silva, Renato Azevedo; Salomão Junior, José; Santos, Deise Machado dos; Chaves, Ana Lúcia Hentsch; Juliano, Carlos Renan Varela; Jannke, Heitor Alberto; Silva Júnior, Lande Vieira da; Groll, Andrea Von; Silva, Pedro Eduardo Almeida daCagA of Helicobacter pylori undergoes tyrosine phosphorylation in a region containing differing numbers of repeat sequences (EPIYAs), which can result in a modulation of the inflammatory response. This study investigated whether the presence of CagA EPIYA variations in strains of H. pylori that are positive for this region contributes to differing degrees of disease severity in the gastric mucosa. In this study, 157 H. pylori–positive patients were included, and of those, 40.8% (64/157) were infected with cagA-positive strains, which were assayed for the presence of CagA EPIYA-ABC, EPIYA-ABCC, and EPIYA-ABCCC. Peptic ulcers were significantly more prevalent in patients infected with strains containing CagA EPIYA-ABCC/ABCCC than in those with CagA EPIYA ABC strains (P = 0.044). This suggests that the number of repetitions of EPIYA-C influences the development of gastroduodenal lesions, highlighting the importance and usefulness of evaluating the cagA gene sequence when making therapeutic intervention decisions in patients infected with H. pylori.
- ItemEvalution of diagnostic methods for the detection of helicobacter pylori in gastric biopsy specimens of dyspeptic patients(2012) Ramis, Ivy Bastos; Moraes, Ernani Pinho de; Fernandes, Márcia Silveira; Raul Andres, Mendoza-Sassi; Rodrigues, Obirajara; Juliano, Carlos Renan Varela; Scaini, Carlos James; Silva, Pedro Eduardo Almeida daHelicobacter pylori infects nearly 50% of the world’s population. This microorganism is accepted as the most important agent of gastritis and as a risk factor for peptic ulcer disease and gastric adenocarcinoma. Currently many diagnostic methods exist for detecting H. pylori, however they all have limitations, thus it is recommend a combination of at least two methods. The aim of this study was to evaluate diagnostic methods, such as in-house urease test, culture and Polymerase Chain Reaction (PCR), for the detection of the H. pylori in gastric biopsy specimens of 144 dyspeptic patients, using as gold standard the association between histology and rapid urease test. According to the gold standard used in this study, 48 (33.3%) patients were infected with H. pylori, while 96 (66.7%) were classified as not infected. The in-house urease test and the PCR were the most sensitive methods (100%), followed by culture (85.4%). However, the inhouse urease test and the culture were the most specific (100%), followed by PCR (75%). In conclusion, this study showed that, in comparison with the combination of histology and rapid urease test, the in-house urease test and the PCR presented 100% of sensitivity in the diagnosis of gastric infection by H. pylori, while the in-house urease test and the culture reached 100% of specificity. These finding suggest that the combination of two or more methods may improve the accuracy of the H. pylori detection.
- ItemGenotypic analysis of Helicobacter pylori by Multiple-Locus Variable-Number Tandem-Repeats method in southern Brazil(2016) Halicki, Priscila Cristina Bartolomeu; Ramis, Ivy Bastos; Vianna, Júlia Silveira; Gautério, Thaísa Bozzetti; Groll, Andrea Von; Silva, Pedro Eduardo Almeida daJustificativa e Objetivos: Apesar de ser utilizado como um método de genotipagem para diferentes microrganismos, poucos estudos relatam a utilização de Multiple-Locus Variable Number of Tandem Repeats Analysis (MLVA) para análise da diversidade clonal do Helicobacter pylori. O objetivo deste estudo foi determinar a variabilidade genética de cepas de H. pylori pelo MLVA no sul do Brasil. Métodos: 95 amostras de DNA de H. pylori foram obtidas a partir de biópsias gástricas de pacientes H. pylori-positivos provenientes de duas cidades do sul do Brasil e a diversidade genética das cepas foi avaliada pelo método MLVA utilizando eletroforese em gel de agarose. Para a seleção dos loci a serem analisados neste estudo, foi realizada uma análise in silico de 12 loci previamente descritos na literatura. Resultados: A partir da análise in silico, apenas quatro loci foram considerados viáveis para a análise genotípica das cepas, resultando em 90 cepas distribuídas em oito grupos diferentes e cinco cepas órfãs. Conclusões: Apesar de o método MLVA permitir fazer inferências acerca da diversidade genética de uma população, nossos resultados mostraram que os métodos de genotipagem do H. pylori devem ser criticamente avaliados antes de serem utilizados nessa região do Brasil.
- ItemDrug resistance in Helicobacter pylori(2016) Vianna, Júlia Silveira; Ramis, Ivy Bastos; Soares, Daniela Fernandes Ramos; Groll, Andrea Von; Silva, Pedro Eduardo Almeida daBackground Helicobacter pylori has a worldwide distribution and is associated with the pathogenesis of various diseases of the digestive system. Treatment to eradicate this microorganism involves the use of a combination of antimicrobials, such as amoxicillin, metronidazole, clarithromycin, and levofloxacin, combined with proton pump inhibitors. Although the current therapy is effective, a high rate of treatment failure has been observed, mainly because of the acquisition of point mutations, one of the major resistance mechanisms developed by H. pylori. This phenomenon is related to frequent and/or inappropriate use of antibiotics. Conclusion This review reported an overview of the resistance to the main drugs used in the treatment of H. pylori, confirming the hypothesis that antibacterial resistance is a highly local phenomenon and genetic characteristics of a given population can influence which therapy is the most appropriate.
- ItemRelationship of interleukin-1B gene promoter region polymorphism with Helicobacter pylori infection and gastritis(2015) Ramis, Ivy Bastos; Vianna, Júlia Silveira; Halicki, Priscila Cristina Bartolomeu; Lara, Caroline; Tadiotto, Thássia Fernanda; Maciel, João Batista da Silva; Gonçalves, Carla Vitola; Groll, Andrea Von; Dellagostin, Odir Antonio; Silva, Pedro Eduardo Almeida daIntroduction: Helicobacter pylori infection is associated with gastritis, peptic ulcer disease and gastric carcinoma. The severity of damage is determined by the interplay between environmental/behavioral factors, bacterial pathogenicity genes and host genetic polymorphisms that can influence the secretion levels of inflammatory cytokines. Accordingly, this study aimed to identify polymorphisms in the IL-1B and IL-1RN genes and their associations with H. pylori infection, cagA gene of H. pylori, and gastroduodenal diseases. Methodology: Gastric biopsy samples from 151 patients infected with H. pylori and 76 uninfected individuals were analyzed. H. pylori infection was diagnosed by histology and PCR. Polymorphisms at positions -511, -31 and +3954 of the IL-1B gene were detected by PCR-RFLP, and an analysis of the VNTR polymorphism of the IL-1RN gene was performed by PCR. Results: It was observed that the presence of the T/T genotype at position -511 and the C/C genotype at position -31 were associated with H. pylori infection and with an increased risk of gastritis in H. pylori-positive patients. Additionally, strains from patients H. pylori-positive carrying the cagA gene was significantly related with the T/T genotype at position -511 of IL-1B. No association of polymorphisms at position +3954 of IL-1B and in the IL-1RN with H. pylori infection and with risk of severe gastric diseases was found. Conclusions: We demonstrated that polymorphisms in the promoter region of the IL-1B gene (at positions -511 and -31) are associated with an enhanced risk of H. pylori infection as well as gastritis in H. pylori-positive patients.
- ItemCagE as a biomarker of the pathogenicity of Helicobacter pylori(2013) Ramis, Ivy Bastos; Vianna, Júlia Silveira; Silva Júnior, Lande Vieira da; Groll, Andrea Von; Silva, Pedro Eduardo Almeida daIntroduction: Helicobacter pylori infection is associated with gastro-duodenal diseases. Genes related to pathogenicity have been described for H. pylori and some of them appear to be associated with more severe clinical outcomes of the infection. The present study investigates the role of cagE as a pathogenicity biomarker of H. pylori compare it to cagA, vacA, iceA and babA2 genes and correlate with endoscopic diagnoses. Methods: Were collected biopsy samples of 144 dyspeptic patients at the Hospital of the Federal University of Rio Grande, Rio Grande do Sul, Brazil. After collection, the samples were sent for histological examination, DNA extraction and detection of all putative pathogenicity genes by PCR. Results: Of the 144 patients undergoing endoscopy, 57 (39.6%) presented H. pylori by histological examination and PCR by detection of the ureA gene. Based on the endoscopic diagnoses, 45.6% (26/57) of the patients had erosive gastritis, while 54.4% (31/57) had enanthematous gastritis. The genes cagA, cagE, vacAs1/m1, vacAs1/m2 and iceA1 were related to erosive gastritis, while the genes vacAs2/m2, iceA2 and babA2 were associated to enanthematous gastritis. We found a statistically significant association between the presence of cagE and the endoscopic diagnosis. However, we detect no statistically significant association between the endoscopic diagnosis and the presence of cagA, vacA, iceA and babA2, although a biological association has been suggested. Conclusions: Thus, cagE could be a risk biomarker for gastric lesions and may contribute to a better evaluation of the H. pylori pathogenic potential and to the prognosis of infection evolution in the gastric mucosa.
- ItemPolymorphisms of the IL-6, IL-8 and IL-10 genes and the risk of gastric pathology in patients infected with Helicobacter pylori(RAMIS, Ivy Bastos et al. Polymorphisms of the IL-6, IL-8 and IL-10 genes and the risk of gastric pathology in patients infected with Helicobacter pylori. Journal of Microbiology, Immunology and Infection, p. 1-7, 2015. Disponível em: . Acesso em: 16 jan. 2017., 2006) Ramis, Ivy Bastos; Vianna, Júlia Silveira; Gonçalves, Carla Vitola; Groll, Andrea Von; Dellagostin, Odir Antonio; Silva, Pedro Eduardo Almeida daBackground/Purpose Helicobacter pylori-induced gastric mucosal inflammation is mediated by proinflammatory and anti-inflammatory cytokines. Polymorphisms in genes that code cytokines influence cytokine secretion levels and appear to contribute to the risk of gastric diseases. In this sense, we performed this study to identify the polymorphisms in the IL-6, IL-8, and IL-10 genes and their associations with H. pylori infection and gastric pathologies. Methods Gastric biopsy samples of 151 patients infected with H. pylori and 76 uninfected individuals were used. Helicobacter pylori infection was diagnosed by histological examination and the detection of the ureA and glmM genes. The polymorphisms in the IL-6 (at position −174), IL-8 (at position −251), and IL-10 (at position −819) were detected by polymerase chain reaction–restriction fragment length polymorphism. Results Among the genetic polymorphisms studied, we observed that only the presence of the A allele at position −251 of the IL-8 gene was significantly associated with H. pylori infection. In addition, patient carriers of the A/A genotype at position −251 of the IL-8 gene and carriers of the T allele at position −819 of the IL-10 gene had an increased risk of peptic ulcer disease in the presence of H. pylori infection. We did not find a correlation between polymorphisms in the IL-6, IL-8, and IL-10 genes and a higher risk of gastric carcinoma. Conclusion We demonstrated that polymorphisms in the IL-8 gene was significantly associated with H. pylori infection. Furthermore, polymorphisms in the IL-8 and IL-10 genes were associated with an enhanced risk of peptic ulcer disease in H. pylori-positive patients.