Navegando por Autor "BARILE, Katarine Antonia dos Santos"

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Acesso aberto (Open Access)
Determination of strains of Helicobacter pylori and of polymorphism in the interleukin-8 gene in patients with stomach cancer
(2011) VINAGRE, Ruth Maria Dias Ferreira; CORVELO, Tereza Cristina de Oliveira; ARNAUD, Vanda Catão; LEITE, Ana Claudia Klautau; BARILE, Katarine Antonia dos Santos; MARTINS, Luisa Caricio
CONTEXT: Gastric neoplasia is the second most common cause of death by cancer in the world and H. pylori is classified as a type I human carcinogen by the World Health Organization. However, despite the high prevalence of infection by H. pylori around the world, less than 3% of individuals carrying the bacteria develop gastric neoplasias. Such a fact indicates that evolution towards malignancy may be associated with bacterial factors in the host and the environment. OBJECTIVES: To investigate the association between polymorphism in the region promoting the IL-8 (-251) gene and the H. pylori genotype, based on the vacA alleles and the presence of the cagA gene, using clinical and histopathological data. METHODS: In a prospective study, a total of 102 patients with stomach cancer and 103 healthy volunteers were analysed. Polymorphism in interleukin 8 (-251) was determined by the PCR-restriction fragment length polymorphism reaction and sequencing. PCR was used for genotyping the vacA alleles and the cagA in the bacterial strains PCR. Gastric biopsies were histologically assessed. RESULTS: The H. pylori serology was positive for 101 (99%) of all patients analysed, and 98 (97%) of them were colonized by only one strain. In patients with monoinfection, 82 (84%) of the bacterial strains observed had the s1b/m1 genotype. The cagA gene was detected in 74 (73%) of patients infected by H. pylori. The presence of the cagA gene was demonstrated as associated with the presence of the s1b/m1 genotype of the vacA gene (P = 0.002). As for polymorphism in the interleukin 8 (-251) gene we observed that the AA (P = 0.026) and AT (P = 0.005) genotypes were most frequent in the group of patients with gastric adenocarcinoma. By comparing the different types of isolated bacterial strains with the interleukin -8 (-251) and the histopathological data we observed that carriers of the A allele (AT and AA) infected by virulent strains (m1s1 cagA+) demonstrated a greater risk of presenting a degree of inflammation (OR = 24.75 CI 95% 2.29-267.20 P = 0.004) and increased neutrophilic activity (OR = 28.71 CI 95% 2.62-314 P = 0.002) in the gastric mucosa. CONCLUSION: Our results demonstrate that the interaction between polymorphism in the interleukin -8 (-251) gene, particularly with carriers of the A allele and the infecting type of H. pylori strain (s1m1 cagA positive) performs an important function in development of gastric adenocarcinoma.
Acesso aberto (Open Access)
Helicobacter pylori em crianças e associação de cepas CagA na transmissão mãe-filho na Amazônia brasileira
(Universidade Federal do Pará, 2009-06) D’ANNIBALE, Vivian Lúcia Aslan; MARTINS, Luisa Caricio; CARNEIRO, Lígia Maia; BARILE, Katarine Antonia dos Santos; CORVELO, Tereza Cristina de Oliveira
The prevalence of Helicobacter pylori infection was investigated in blood samples from 100 children aged 1 to 12 years and from their mothers, by means of the indirect hemagglutination and anti-CagA methods, using ELISA assays. From these 100 children, 79 stool samples were obtained and bacterial antigens in the stools were investigated using capture ELISA. The antigens were detected in 54.4% (43/79) of the children, and serum antibodies in 43% (34/79). These methods presented similar performance, with greatest disagreement among the children aged 1 to 4 years. The seroprevalence was 50% (50/100) among the children and 86% (86/100) among the mothers. Infected mothers represented a risk factor that was 19 times greater than that of seronegative mothers, with regard to infecting their children (p < 0.05), especially the mothers with CagA+ strains (p < 0.05). Direct person-to-person contact may be a transmission method for this infection.