Search

Objective: We aimed to determine whether cytotoxin-positive Helicobacter pylori strains are associated with gastric carcinoma., Methods: We studied 130 patients: 57 H. pylori-positive patients with gastric carcinoma, 53 H. pylori-positive patients without gastric carcinoma, and 20 H. pylori-negative subjects. The ability of H. pylori strains to produce vacuolating cytotoxin was tested in INT-407 and HeLa cells. The presence of antibodies to cytotoxin was investigated in blood serum from all subjects by immunoblotting. Fragments of the gastric mucosa from patients without gastric carcinoma and H. pylori-negative subjects were obtained for histopathological study., Results: Considering the results as a whole, 40 (70.2%) patients with and 22 (41.5%) without gastric carcinoma were colonized by cytotoxin-positive strains. Antibodies against cytotoxin were not observed in the serum from 17 (29.8%) gastric carcinoma patients and from 31 (58.5%) patients without gastric carcinoma. H. pylori strains isolated from these patients did not produce cytotoxin in vitro. In regard to cytotoxin positivity, a significant difference was observed between patients with and without gastric carcinoma (p=0.004; odds ratio [OR]: 3.3; 95% confidence interval [CI]: 1.4-7.9). Higher scores of mononuclear (p=0.0001) and polymorphonuclear (p=0.000003) cells were observed in the antral mucosa from H. pylori-positive patients without gastric carcinoma infected by cytotoxin-positive strains than in those harboring cytotoxin-negative strains., Conclusion: Cytotoxin-producing H. pylori strains were more frequently observed in patients with gastric carcinoma and this aspect emphasizes the role of cytotoxin in the genesis of the tumor.

Objective: To study the epidemiology of Helicobacter pylori infection in children of low socioeconomic level in Belo Horizonte, Brazil., Methods: Serum samples were collected from 249 children (134 boys, 115 girls, mean age 6.4 yr, range 1 month to 18 yr) at an outpatient clinic of the University Hospital/UFMG, Belo Horizonte, Brazil. Information obtained included age, gender, nutritional status, family income, domestic crowding, sewage, and water supply. H. pylori infection was identified by means of an indirect immunofluorescence assay (sensitivity, 94.3% and specificity, 100.0% in children) which detects the presence of IgG against H. pylori., Results: Ninety-seven percent of the children had an annual family income of US $5,000.00 or less, 93.7% had city water, and 79.5% had sewage. In 90.2% of the families, the number of persons per room was > 1. Of the 241 children evaluated for nutritional status, 129 (53.5%) were considered to be eutrophic, 62 (25.7%) presented mild malnutrition, 34 (14.1%) moderate malnutrition, and 16 (6.6%) severe malnutrition. The prevalence of H. pylori infection was 34.1% and was similar in boys (35.8%) and girls (32.2%). The prevalence of H. pylori infection increased significantly (p = 0.001) with age as follows: 1 month-2 yr, 16.4% (11/67); 3-5 yr, 36.7% (22/60); 6-8 yr, 29.5% (13/44); 9-11 yr, 48.8% (21/43); 12-14 yr, 42.8% (9/21); and 15-18 yr, 64.3% (9/14). There was no significant difference in H. pylori infection with regard to nutritional status or the presence of sewage., Conclusion: The results of present study demonstrate that in Belo Horizonte, Brazil, as also reported in other developing countries, H. pylori infection occurs early and increases with age.

The histamine concentration of the oxyntic mucosa was determined in Helicobacter pylori-positive patients with duodenal ulcer before and after antimicrobial therapy and in H. pylori-negative subjects. Determination of serum gastrin was also performed in duodenal ulcer patients before and after H. pylori eradication. The histamine content of the oxyntic mucosa was lower in patients with duodenal ulcer than in H. pylori-negative subjects, but it increased after H. pylori eradication. Conversely, in patients in whom therapy failed to eradicate the microorganism, the histamine content remained unchanged. Serum gastrin levels fell after microorganism eradication, and the percentage of this fall was correlated with the percentage of increase in gastric histamine. In conclusion, our findings suggest that abnormalities of histamine store present in duodenal ulcer patients might be a feature of H. pylori infection.

We describe seven patients with Helicobacter pylori acute gastritis who presented endoscopical picture simulating gastric carcinoma or lymphoma. H. pylori was detected on the antral and on the oxyntic mucosa of all patients. At histological examination, no evidence of malignancy was observed in any of the patients. In the antral mucosa there were edema, hyperemia, and intense polymorphonuclear leukocyte infiltration (neutrophils and some eosinophils) in the lamina propria, mucus layer, and inside the glands. The patients were treated with amoxycillin (2 g/day for 2 months) associated with metronidazole (750 mg/day for 15 days), which reduced the symptoms dramatically. Endoscopy and biopsy, repeated 4 wk after treatment was stopped, showed that the patients had been cleared of H. pylori, and indicated a marked improvement of endoscopical and histological gastritis. These findings indicated that H. pylori acute gastritis can mimic gastric carcinoma or lymphoma. Therefore, histology and detection of H. pylori are essential for an accurate diagnosis.

The presence of Campylobacter pylori and histological changes of gastric mucosa were studied in 50 consecutive patients with gastric complaints. C. pylori was isolated from the antrum, body, and fundus of 40 patients with (n = 20) and without (n = 20) duodenal ulcer. The incidence of gastritis was not significantly different in the antrum of C. pylori-positive patients with and without ulcer. Otherwise, oxyntic mucosa of both body and fundus regions exhibited gastritis in 64.1% of the C. pylori-positive non-ulcer patients, whereas those with duodenal ulcer presented oxyntic mucosa that was histologically normal or near normal.