-Background -The mechanisms whereby Helicobacter pylori produces different pathological manifestations in the stomach and duodenum are not fully understood. Considering the geographic diversity in the prevalence of virulence factors of this microorganism and their association with the development of different diseases, the search for pathogenicity markers such as CagA and VacA alleles by molecular techniques has intensified. Objectives -To investigate the presence of H. pylori infection and the frequency of different genotypes of this bacterium in patients with gastrointestinal diseases from Northern Brazil, and to establish their association with the histopathological findings. Methods -In a prospective study, samples were collected from 554 patients with different gastrointestinal diseases (gastritis, duodenal ulcer, gastric ulcer, and gastric cancer) seen at a referral hospital attending the entire State of Pará, located in the metropolitan region of Belém. Data such as gender and age obtained with an epidemiological questionnaire were analyzed. The presence of H. pylori and the bacterial genotype were investigated by PCR. Gastric biopsies were assessed histologically. Results -The prevalence of H. pylori infection was 91%. Infection was more frequent among patients with gastric ulcer and gastric cancer. In these groups, there was a predominance of men and older patients when compared to the other two groups studied. The predominant bacterial genotype was s1m1cagA+, which was more frequent among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between s1m1cagA+ strains and a higher degree of inflammation, neutrophil activity and development of intestinal metaplasia. Conclusion -The present study demonstrates a high incidence of H. pylori infection in the patients analyzed, especially among those with gastric ulcer and gastric cancer. Virulent s1m-1cagA+ strains predominated and were associated with more severe lesions. HEADINGS -Helicobacter pylori. Helicobacter infections. Gastrointestinal diseases. Genotype.
-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 PCRrestriction 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.
Our study shows that the interaction between the type of infectious strain and the Th1 immune response can influence and perpetuate gastric inflammation, and thus contributes to the development of the different clinical manifestations of H. pylori infection.
-Context -Although more than half of the world's population is colonized with Helicobacter pylori, it remains unknown why this organism is able to produce severe disease in some hosts and be innocuous in others. The clinical outcome of infection is determined by several factors, including differences in the host response to bacterial stimulation, specific virulence factors of the organism and environmental influences, or a combination of these factors. Objectives -This study compared the prevalence of H. pylori infection and risk factors (infection with CagA+ strains, excessive alcohol consumption, smoking, and inadequate eating habits) between patients with different gastrointestinal disorders and associated these risk factors with the histopathological findings.Methods -In a prospective study, samples were collected from 442 patients and a standardized questionnaire regarding lifestyle habits (excessive alcohol consumption, smoking, and eating habits) was applied. The presence of H. pylori and of the cagA gene was investigated by polymerase chain reaction (PCR). Gastric biopsies were obtained for histological assessment. Results -The frequency of alcohol consumption, smoking, inadequate diet and infection with CagA+ H. pylori was higher among patients with peptic ulcer and adenocarcinoma when compared to those with gastritis. Gastric inflammation was more pronounced in patients infected with CagA+ strains. Conclusion -We conclude that infection with CagA+ H. pylori strains, excessive alcohol consumption, smoking and inadequate eating habits increase the risk of developing peptic ulcer and gastric carcinoma.
The Helicobacter pylori is associated with the development of different diseases. The clinical outcome of infection may be associated with the cagA bacterial genotype. The aim of this study was to determine the EPIYA patterns of strains isolated from patients with gastritis and gastric adenocarcinoma and correlate these patterns with the histopathological features. Gastric biopsy samples were selected from 384 patients infected with H. pylori, including 194 with chronic gastritis and 190 with gastric adenocarcinoma. The presence of the cagA gene and the EPIYA motif was determined by PCR. The cagA gene was more prevalent in patients with gastric cancer and was associated with a higher degree of inflammation, neutrophil activity, and development of intestinal metaplasia. The number of EPIYA-C repeats showed a significant association with an increased risk of gastric carcinoma (OR = 3.79, 95% CI = 1.92–7.46, and P = 0.002). A larger number of EPIYA-C motifs were also associated with intestinal metaplasia. In the present study, infection with H. pylori strains harboring more than one EPIYA-C motif in the cagA gene was associated with the development of intestinal metaplasia and gastric adenocarcinoma but not with neutrophil activity or degree of inflammation.
-Context -Stomach cancer is the second leading cause of death due to cancer in the world and the incidence of this disease continues to be high in Brazil. In the Northern region, gastric cancer is the second most frequent cancer among men and the third among women. In the State of Pará, stomach adenocarcinoma is a public health problem since mortality rates are above the Brazilian average. Objective -To analyze the clinical and anatomopathological profile of stomach adenocarcinoma in patients seen at Ofir Loiola Hospital. Methods -In a retrospective study, records from 302 patients with gastric cancer undergoing surgery between 2006 and 2008 were analyzed. Data regarding patient profile, early symptoms, alterations upon physical examination, type of surgery, and macroscopic and histological findings were obtained from the records. Results -Most patients (63.9%) were men, 48% were older than 60 years, 50.9% were from the metropolitan region of Belém, 68.2% presented epigastric pain as an early symptom, and abdominal tenderness upon palpation was observed in 63.7%. The antrum was the most affected anatomical site (62.1%), followed by the gastric body (26.9%). Borrmann III (ulcerated-infiltrative) was the predominant endoscopic type. Adenocarcinoma accounted for 95.4% of all cases, including the intestinal type in 56.6% and the diffuse type in 41.3%. Most patients had stage IIIB and IV tumors and total gastrectomy was the most frequent type of surgery (37.4%). Conclusion -The present study demonstrated that gastric adenocarcinoma mainly affected men over the age of 60 who were from the metropolitan region of Belém. Most adenocarcinomas were in an advanced stage at the time of diagnosis, a fact requiring more aggressive surgical resection in these cases. These data highlight the urgent need for the implementation of preventive measures and early detection programs of gastric cancer. HEADINGS -Stomach neoplasms. Adenocarcinoma.
Introduction:This study compares virulence markers of Helicobacter pylori isolated from patients in 2 cities in the Brazilian Amazon. Methods: The study analyzed 168 patients with chronic gastritis from Belém and 151 from Bragança, State of Pará, Brazil. Levels of bacterial DNA associated with cagA and vacA alleles were checked by PCR, and hematoxylin-eosin staining was used for histologic diagnosis. Results: In Bragança 87% of patients were genotype s1m1 cagA-positive (s1m1 cagA + ), compared with 76% in Belém. In samples from patients in both cities, there was an association between s1m1 cagA + strains and gastric mucosal damage. Conclusions: Both cities have a high frequency of s1m1 cagA + strains of H. pylori.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.