Osamu Kobayashi

BACKGROUND: Helicobacter pylori is recognized as one of the possible causes of gastric carcinoma. There have been few studies on the relationship between H. pylori and gastric carcinoma in patients younger than 40 years. METHODS: Data and sera were collected from the cases (105 hospitalized patients younger than 40 years with gastric carcinoma from 9 hospitals in the Kanto-Shin-Etsu Area in Japan) and controls (102 hospitalized control subjects and 101 screening control subjects) whose sex and age (within 4 years) were matched. The serum anti-H. pylori immunoglobulin G antibody was measured, and the odds ratio (OR) for the association between seropositivity and gastric carcinoma was calculated. RESULTS: The OR (95% confidence interval) was 13.3 (5.3-35.6). For women, the OR was 32.8, whereas for men it was 6.8. The OR for patients with early gastric carcinoma was 20.8, and for patients with advanced disease, it was 10.8. The OR for intestinal-type carcinoma was 18.0, and for diffuse-type carcinoma, it was 12.8. The OR for proximal carcinoma was 11.3, and for distal carcinoma it was 14.8. CONCLUSION: The OR for these young subjects was considerably larger than that for the older subjects in previously published studies. Among those younger than 40 years of age, early stage carcinoma has a stronger association with H. pylori than advanced carcinoma, and intestinal- and diffuse-type carcinomas have an association with H. pylori.

The reduction of acetate ester synthesis by aeration and the addition of unsaturated fatty acids to the medium has been reported to be the result of the reduction in alcohol acetyltransferase (AATase) activity induced by inhibition of this enzyme. However, regulation of the AATase gene ATF1 has not been reported. In this study, ATF1 gene expression was studied by Northern analysis, and the results showed that the ATF1 gene was repressed both by aeration and by unsaturated fatty acids. The results also showed that the reduction of AATase activity is closely related to the degree of repression of ATF1 mRNA, which suggested that the gene repression is the primary means of reducing AATase activity in vivo. Using the Escherichia coli lacZ gene as a reporter gene, it was shown that a 150-bp fragment of the 5' flanking sequence played a major role in the repression by aeration and unsaturated fatty acid addition.