Ryugo Sato

Efficacy of triple therapy comprising rabeprazole, amoxicillin and metronidazole for second‐line Helicobacter pylori eradication in Japan, and the influence of metronidazole resistance

Background : The widespread use of eradication therapy for Helicobacter pylori in Japan has led to an increase in antibiotic‐resistant strains and the problem of re‐treatment in cases of eradication failure.

Eradication rates of clarithromycin-resistant Helicobacter pylori using either rabeprazole or lansoprazole plus amoxicillin and clarithromycin

Background : The resistance of Helicobacter pylori to clarithromycin has become one of the primary reasons for eradication failure.

Influence of bile reflux and Helicobacter pylori infection on gastritis in the remnant gastric mucosa after distal gastrectomy

BackgroundTwo main pathogenic factors, bile reflux and Helicobacter pylori infection, have been identified in the remnant stomach, but it is still unclear which factor is important in the pathogenesis of gastritis in the remnant stomach after distal gastrectomy.MethodsIn 184 patients who had had distal gastrectomy performed using the Billroth-I procedure (B-I; n-106), Billroth-II procedure (B-II; n-36), and jejunal interposition (J-I; n-42) we examined the severity of remnant gastritis endoscopically and carried out examinations for H. pylori infection and histological examination.ResultsThe endoscopic severity of remnant gastritis was grade 1 or more in 101 of the 106 B-I patients (95.3%) and in all 36 B-II patients (100%). But, of the 42 J-I patients, the grade was 0 in 33 (78.6%). The endoscopic severity of remnant gastritis was significantly milder for J-I than for B-I (P < 0.001) and B-II (P < 0.001). H. pylori infection was confirmed in 59 of the 106 B-I patients (55.6%), 21 of the 36 B-II patients (58.3%), and 32 of the 42 J-I patients (76.1%). The rate of H. pylori infection was higher for J-I patients than for B-I (P < 0.05), but not for B-II patients (P = 0.1495). The severity of chronic and active inflammatory cellular infiltration tended to be inverse proportional relation with the endoscopic severity of the remnant gastritis. Furthermore, the histological inflammation and activity scores of H. pylori-positive patients were higher than those of H. pylori-negative patients, without regard to the endoscopic grade of gastritis.ConclusionsReconstruction techniques play an important role in the prevention of bile reflux, and we found that endoscopically more severe remnant gastritis was associated with a lower rate of H. pylori infection and with a lower degree of inflammatory cellular infiltration.

Eradication of Helicobacter pylori reduced the immunohistochemical detection of p53 and MDM2 in gastric mucosa

Background:  Although Helicobacter pylori has been regarded as a pathogen of gastric cancer, the mechanism by which H. pylori is involved in gastric carcinogenesis remains unknown. To clarify the role of H. pylori in carcinogenesis, the expression of tumor suppressor p53 and its regulator multiple double minute 2 (MDM2) in gastric mucosa were examined before and after H. pylori eradication.

Duodenal gangliocytic paraganglioma treated with endoscopic hemostasis and resection

Gangliocytic paragangliomas are exceedingly rare tumors that arise in close proximity to the papilla of Vater. There are few reports of the endoscopic resection of duodenal gangliocytic paraganglioma. A 61-year-old woman was admitted with a complaint of melena. Endoscopic examination revealed a pedunculated submucosal tumor with erosion in the third portion of the duodenum. Hemostasis, using a gold probe, was performed. Nine days later, we successfully resected the tumor, using endoscopic polypectomy. To determine the depth of tumor invasion, endoscopic ultrasonography was used. The size of the tumor was 3.0 × 2.5 × 1.0 cm. A total of 25 cases of duodenal gangliocytic paraganglioma have been reported in Japan. Generally, this tumor is considered benign. However, resection was performed in many patients because preoperative diagnosis was impossible. In Japan, no previous studies have reported using endoscopic hemostasis, to our knowledge. Our patient is the fourth in Japan to be treated by endoscopic resection. We report on our patient, with a review of the literature.

Is the Recurrence of Helicobacter pylori Infection After Eradication Therapy Resultant from Recrudescence or Reinfection, in Japan

Background. Reinfection of Helicobacter pylori after eradication is rare in developed countries but most often occurs within 1 year. In the present study, we attempted to differentiate between reinfection and recrudescence of H. pylori strains between 6 months and 6 years after successful eradication in Japan, a country with a high prevalence of H. pylori infection.

Evaluation of Three Different Proton Pump Inhibitors With Amoxicillin and Metronidazole in Retreatment for helicobacter pylori Infection

Goals We compared the eradication results of retreatment of eradication with proton pump inhibitor (PPI) plus amoxicillin and metronidazole for patients with Helicobacter pylori infection not eradicated by initial treatment with PPI plus amoxicillin and clarithromycin. Background In Japan, the guideline proposes that the use of metronidazole in a triple therapy containing PPI, PPI plus amoxicillin and metronidazole is desirable in retreatment. However, there are no reports comparing various retreatment using different PPIs. Methods After initial treatment failure with a PPI plus amoxicillin and clarithromycin, 169 patients were randomized to a PPI (rabeprazole, lansoprazole, or omeprazole) plus amoxicillin and metronidazole given b.i.d. for 7 days. Results Pretreatment susceptibility testing showed a high level of clarithromycin resistance (78%). The over all eradication rates were similar with the 3 PPIs, 91.1% range 90.1 to 91.4 with intention-to-treat analysis. The presence of metronidazole resistance reduced the eradication rate by approximately 40% (from 96.6% to 57.1%, P<0.05). Conclusions In Japan, the combination of a PPI plus amoxicillin and metronidazole provide excellent eradication rates after initial treatment failure with a PPI plus amoxicillin and clarithromycin. The results with metronidazole resistant strains are less satisfactory and pretreatment susceptibility testing may become needed if the prevalence of metronidazole resistant H. pylori increase.

Influence of anti-ulcer drugs used in Japan on the result of (13)C-urea breath test for the diagnosis of Helicobacter pylori infection.

BackgroundThe 13C-urea breath test (UBT) is a simple test for the diagnosis of Helicobacter pylori infection, but several factors have been reported to affect the results of this test. In this study, the effects of the anti-ulcer drugs used in Japan on the results of the UBT were determined.MethodsThe subjects of the study were 64 adult volunteers who tested positive for H. pylori infection by the serum antibody method. Eight classes of anti-ulcer drugs used in Japan were administered at their usual doses to these subjects: lansoprazole, a proton pump inhibitor (PPI); nizatidine, an H2-receptor antagonist (H2RA); and polaprezinc, ecabet sodium, rebamipide, teprenone, cetraxate hydrochloride, and sucralfate, all mucoprotective agents. The study drugs were randomized for administration to the subjects, and each of the drugs was administered for 14 consecutive days. The UBT was performed on days 0, 14, and 21.ResultsThe mean Δ13C‰ in the lansoprazole group was significantly decreased on day 14, to below 10‰, in 4 of 16 subjects, and in 1 of the 4 subjects, the test result was negative, with the Δ13C‰ falling to 1.7‰. The value returned to baseline 1 week after the discontinuation of lansoprazole. The other drugs administered had no significant effect on the result of the UBT, except that the mean Δ13C‰ showed a tendency to decrease after the administration of ecabet sodium and rebamipide.ConclusionsAdministration of a PPI may produce a false-negative UBT result, while other anti-ulcer drugs, for the most part, have little effect on the result of the UBT when used alone.

Enterocromaffin-Like Cell Tumor Induced by Helicobacter pylori Infection in Mongolian Gerbils

Background. Gastric carcinoids are strongly associated with chronic atrophic gastritis A, and it is suggested that hypergastrinemia plays a critical role in development of gastric carcinoids. Since Helicobacter pylori infection causes hypergastrinemia, it is held that H. pylori infection produces gastric carcinoids. We followed the histological changes of H. pylori‐infected stomachs of Mongolian gerbils for a long time.

Effectiveness of minocycline-based triple therapy for eradication of Helicobacter pylori infection.

Background:  Widespread use of eradication therapy for Helicobacter pylori has increased the prevalence of clarithromycin‐resistant strains. The purpose of the present paper was to measure the in vitro antibacterial activity of minocycline against H. pylori, and study the effectiveness of minocycline‐based first‐ and second‐line eradication therapies.