These results suggest that atrophic gastritis is not a normal aging process, but instead is likely to be the result of H. pylori infection, while intestinal metaplasia is caused by both the aging process and H. pylori infection. A decreased risk of intestinal metaplasia found in uninfected female subjects may partly explain the lower prevalence of gastric cancer in females than in males.

INTRODUCTIONUp to now, four regimens have generally been used for the eradication of Helicobacter pylori; namely, a bismuthbased triple therapy, a dual therapy consisting of omeprazole plus amoxycillin or clarithromycin, a standard triple therapy consisting of proton pump inhibitor and two antibiotics, either clarithromycin and metronidazole or amoxycillin, and a quadruple therapy 1 consisting of proton pump inhibitor plus bismuth based triple therapy. As in any other infectious disease it is essential in treatment studies of H. pylori infection to stratify the SUMMARY Background: There have been no reports concerning the ef®cacy and safety of a 1-week quadruple therapy regimen of omeprazole, amoxycillin, roxithromycin and metronidazole for Helicobacter pylori infections and the impact of primary resistance on the eradication rate. Methods: One hundred and sixty-nine consecutive patients with peptic ulcer disease as well as gastritis with biopsy-proven H. pylori infection were entered into an open study of omeprazole 20 mg o.m., amoxycillin 500 mg t.d.s., roxithromycin 150 mg b.d., and metronidazole 250 mg t.d.s. Helicobacter pylori status was determined by urease test, histology and culture. Susceptibility to amoxycillin, metronidazole and roxithromycin was determined by the E-test. Results: H. pylori was eradicated in 155 out of 169 (92%; 95% CI 88±96%) by intention-to-treat analysis, and in 155 out of 163 (95%; 95% CI 92±98%) by per protocol analysis. The prevalence of primary resistance against amoxycillin, roxithromycin and metronidazole was 2 out of 166 (1%), 16 out of 166 (10%) and 27 out of 166 (16%), respectively. H. pylori was eradicated in 25 out of 27 (93%) patients with

To elucidate whether pretreatment with omeprazole decreases the cure rate of Helicobacter pylori infection with a new quadruple therapy, and thus, whether this pretreatment should not be used in clinical practice, we conducted a randomized trial. Ninety patients with chronic peptic ulcer disease and nonulcer dyspepsia, with biopsy-proven H. pylori infection were randomly assigned to the two following regimens: Group 1 (n = 45) received omeprazole 20 mg once daily for 2 weeks (days 1-14), and 500 mg amoxicillin granules and 250 mg metronidazole thrice daily, and roxithromycin 150 mg twice daily for 1 week (days 8-14), Group 2 (n = 45) received the same antibiotic treatment as group 1 for 1 week (days 1-7), in addition to omeprazole treatment for 2 weeks (days 1-14). Four weeks after the treatment ended, endoscopy was repeated, with two biopsy specimens each taken from the antrum and the corpus (total of four specimens) for a urease test, histological analysis, and culture to establish cure of infection. A patient was regarded as cured only if all three methods gave negative results for H. pylori. In the intention-to-treat analysis, 42 of 45 patients (93.3%; 95% confidence intervals [CI], 81.7%-98.6%) in group 1 were cured compared with 43 of 45 patients (95.6%; 95% CI, 84.9%-99.5%) in group 2. In the per-protocol analysis, the corresponding figures were 42/44 (95.5%; 95% CI 84.5%-99.4%) and 43/44 (97.7%; 95% CI, 88.0%-99.9%). There were no significant differences in the cure rate between the two groups on either analysis. All patients, except for one who had an allergic reaction, completed the treatment regimens. Fifty to sixty percent of the patients had no side effects while the rest had mild to moderate side effects. The new quadruple therapy consisting of omeprazole, amoxicillin, metronidazole, and roxithromycin appears suitable for use in clinical practice, as the cure rate was 95% and no severe side effects were observed. Pretreatment with omeprazole did not reduce the cure rate for this new quadruple therapy.

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We have recently identified the principal linear neutralizing B cell epitopes of human T cell leukemia virus type I (HTLV-I) on the envelope protein gp46, amino acids (aa) 187-199, by using a number of human mAbs. We therefore propose that this region would be a good candidate for a peptide-based HTLV-I vaccine. To develop a peptide-based vaccine that can induce a high titer of neutralizing Abs against HTLV-I, we first synthesized peptides of various lengths containing aa187-199. Because the addition of gp46 aa181-186 or aa200-210 to either the N-terminus or C-terminus of SP187-199 did not alter the antigenicity of the principal neutralizing determinant, we prepared two peptide-based vaccines, MAP181-203 and MAP181-210, by conjugating SP181-203 and SP181-210 with a branched polylysine oligomer. In rabbits, X4 to X8 and X8 to X64 titers of the neutralizing Abs were induced by immunization with MAP181-203 and MAP181-210, respectively. Furthermore, high titers of neutralizing Abs (X40 to X320) were elicited in five different strains of rats by immunization with MAP181-210. We also identified the major T cell epitope on gp46 aa194-210 in various strains of rats immunized with MAP181-210. Furthermore, the peripheral T lymphocytes obtained from the majority of HTLV-I-infected patients including HTLV-I-associated myelopathy/tropical spastic paraparesis, adult T cell leukemia/lymphoma, and healthy carriers, proliferated in response to the peptides containing aa194-210. These results indicated that MAP181-210 contains a T cell helper epitope on aa194-210 not only in rats and rabbits, but also in humans with various HLA haplotypes. It is therefore possible that MAP181-210 could become one of the candidates for a peptide-based HTLV-I vaccine for human use.