Ryuichi Ohkura

Impact of rabeprazole, a new proton pump inhibitor, in triple therapy for Helicobacter pylori infection—comparison with omeprazole and lansoprazole

: A recent trend in curative therapy for Helicobacter pylori infection is the so‐called triple therapy, which consists of a proton pump inhibitor (PPI) and two different antimicrobials. Various regimens employing this triple therapy have been reported. However, little is known about the effectiveness of rabeprazole, a recently developed proton pump inhibitor, when used in the triple therapy.

Alteration of histological gastritis after cure of Helicobacter pylori infection

Background : It is still disputed whether gastric atrophy or intestinal metaplasia improves after the cure of Helicobacter pylori infection.

Addition of Metronidazole to Rabeprazole-Amoxicillin-Clarithromycin Regimen for Helicobacter pylori Infection Provides an Excellent Cure Rate with Five-Day Therapy

Background. New triple therapy for eradication of Helicobacter pylori based on a proton pump inhibitor (PPI) provides a cure rate of approximately 90% with few adverse effects. Recently, a PPI‐based quadruple therapy, which consists of a PPI plus bismuth‐based triple therapy for 7 days, has been studied, and a sufficient eradication rate has been achieved. However, a shorter duration results in improved compliance. In this study, newly developed short‐term, simple twice‐daily quadruple therapy consisting of rabeprazole, amoxicillin, clarithromycin, and metronidazole (RACM) was compared with a PPI‐based triple‐therapy regimen for eradication of H. pylori.

Altered localization and expression of tight-junction proteins in a rat model with chronic acid reflux esophagitis.

BackgroundThe esophageal tight junction is responsible for the paracellular sealing of the epithelium. Alteration of the expression of tight-junction proteins plays crucial roles in the pathogenesis of some human diseases. The aim of this study was to investigate the distribution and expression pattern of tight-junction proteins in the esophageal mucosa of control rats and rats with reflux esophagitis.MethodsChronic acid reflux esophagitis was experimentally induced by operation in rats. The animals were killed on days 7 and 14 after the operation. The thickness of the mucosa and the 5-bromo-2-deoxyuridine (BrdU) labeling index were assessed. The expression pattern of the tight-junction proteins claudin 1-4 and occludin in the esophageal mucosa was investigated by immunofluorescence staining and Western blotting in the controls and esophagitis rats.ResultsIn the esophagitis model, the thickness and BrdU labeling index increased with time. In control rats, claudin-1, -3, and -4 were localized on the cellular membranes of esophageal epithelial cells, mainly in the spinous and granular layers, while claudin-2 was not detected in any layer. Occludin was seen on the cellular membranes in all esophageal mucosal layers. In the esophagitis rats, the expression of claudin-1 was increased both in the plasma membrane and in the cytoplasm around the erosion in the spinous and granular layers. The expression of claudin-4 and occludin shifted to the cytoplasm from the plasma membrane in the spinous and granular layers. In contrast, the expression of claudin-3 was decreased in the spinous and granular layers.ConclusionsThe localization and the expression patterns of tight-junction proteins were different in the controls and the rat esophagitis model. The expression of claudin-3 in the esophageal mucosa was decreased, while that of claudin-1 was increased. It is postulated that these alterations in tight-junction proteins most likely increase the permeability of the esophageal the epithelium, thereby impairing the defense mechanism of this epithelium.

Usefulness of a novel enzyme immunoassay for the detection of Helicobacter pylori in feces.

Background: In this study we assessed the reliability of a newly developed enzyme immunoassay (HpSA) kit for detecting Helicobacter pylori antigen in stool. Methods: This study included 309 patients, 147 of whom were defined as positive and 162 as negative by the 13C-urea breath test, rapid urease test, and pathologic findings. From these patients fresh stool specimens were collected for HpSA. Results: When 0.100 was adopted as the cut-off value, in accordance with the manufacturers recommendations, the sensitivity, specificity, and accuracy of the HpSA were 98.0%, 87.0%, and 92.2%, respectively. However, these values were much improved when a cut-off value of 0.300 was adopted, which was obtained with our receiver-operator characteristics curve; with this value the sensitivity, specificity, and accuracy of HpSA were 93.9%, 95.7%, and 94.8%, respectively. Conclusion: These results indicate that HpSA is a highly reliable diagnostic method for H. pylori infection and is useful in confirming eradication.BACKGROUND In this study we assessed the reliability of a newly developed enzyme immunoassay (HpSA) kit for detecting Helicobacter pylori antigen in stool. METHODS This study included 309 patients, 147 of whom were defined as positive and 162 as negative by the 13C-urea breath test, rapid urease test, and pathologic findings. From these patients fresh stool specimens were collected for HpSA. RESULTS When 0.100 was adopted as the cut-off value, in accordance with the manufacturers recommendations, the sensitivity, specificity, and accuracy of the HpSA were 98.0%, 87.0%, and 92.2%, respectively. However, these values were much improved when a cut-off value of 0.300 was adopted, which was obtained with our receiver-operator characteristics curve; with this value the sensitivity, specificity, and accuracy of HpSA were 93.9%, 95.7%, and 94.8%, respectively. CONCLUSION These results indicate that HpSA is a highly reliable diagnostic method for H. pylori infection and is useful in confirming eradication.

Efficacy of reduced dosage of rabeprazole in PPI/AC therapy for Helicobacter pylori infection. Comparison of 20 and 40 mg rabeprazole with 60 mg lansoprazole.

Proton pump inhibitor (PPI)- based triple therapy has been a recent trend for treatment of Helicobacter pylori infection, with the PPI–amoxicillin–clarithromycin (PPI/AC) regimen being one of the most popular. We have reported the effectiveness of PPI/AC regimens in the Japanese population and have demonstrated that the effectiveness of 40 mg rabeprazole, a recently developed PPI, is similar to that of 40 mg of omeprazole and 60 mg of lansoprazole when used in combination with amoxicillin and clarithromycin. In this study, we focused on whether 20 mg of rabeprazole is effective in our patient population by comparing that dosage with 40 mg of rabeprazole and 60 mg of lansoprazole. In all, 308 H. pylori-infected patients [236 men and 72 women; age (mean ± sem) 49.3 ± 0.6 years] with peptic ulcer disease (N = 270) or nonulcer dyspepsia (N = 38) were randomly assigned to one of three different PPI/AC regimens for seven days: LAC (N = 104), consisting of lansoprazole 30 mg twice a day, amoxicillin 500 mg three times a day, and clarithromycin 200 mg twice a day; RAC (N = 104), consisting of rabeprazole 20 mg twice a day, amoxicillin 500 mg three times a day, and clarithromycin 200 mg twice a day; and the R1/2AC regimen (N = 100), which included rabeprazole 10 mg twice a day, amoxicillin 500 mg three times a day, and clarithromycin 200 mg twice a day. Cure of the infection was determined by the [13C]urea breath test one month after completion of the treatment. Intention-to-treat based and per-protocol based cure rates for the LAC, RAC, and R1/2AC regimens were 82.7 (95% CI, 74–89) and 88.7% (81–94), 85.6 (77–92) and 89.8% (82–95), and 87.0 (79–93) and 89.7% (82–95), respectively. Although adverse effects were reported by 20.3% of the patients, these affected compliance in only five patients in the RAC and LAC regimens and none in the R1/2AC group. Overall complete compliance was achieved in 94.7% of interviewed patients. In conclusion, the effectiveness of the PPI/AC regimen with 20 mg of rabeprazole is comparable with and even safer than that of 40 mg of rabeprazole and 60 mg of lansoprazole in our patient population.

Strategy for retreatment of therapeutic failure of eradication of Helicobacter pylori infection

A proton pump inhibitor (PPI)‐based triple therapy consisting of a PPI, amoxicillin (A) and clarithromycin (C) or metronidazole (M) provides an eradication rate ranging from 80 to 90%. However, there have been few controlled studies with regard to the most effective regimen to re‐treat patients after failure of the first‐line therapy. Accordingly, we retrospectively reviewed our experiences and compared regimens with different combinations of antimicrobials to determine the optimal retreatment regimen.

Five-day proton pump inhibitor-based quadruple therapy regimen is more effective than 7-day triple therapy regimen for Helicobacter pylori infection

There have been no reports that describe whether 5‐day quadruple therapy (rabeprazole + amoxicillin + clarithromycin + metronidazole; RACM) could substitute for standard 7‐day triple therapy as a first‐line therapy for Helicobacter pylori.

Is antimicrobial susceptibility testing necessary before second-line treatment for Helicobacter pylori infection?

Background:  An antimicrobial susceptibility test for Helicobacter pylori before second‐line treatment is often performed, although whether the test is truly necessary remains unknown.

Usefulness of the [13C]‐urea breath test for detection of Helicobacter pylori infection in fasting patients

Most of the reported [13C]‐urea breath test procedures use a test meal, which is believed to assist in the spread of the [13C]‐urea solution into the entire stomach, as results without a test meal may mainly reflect urease activity in the antrum. Yet, procedures for the [13C]‐urea breath test and interpretation of the obtained 13C excess value have not been well established. We carried out the present study to validate the usefulness of the [13C]‐urea breath test in fasting subjects and to establish cut‐off values. [13C]‐Urea breath tests were performed on 258 Helicobacter pylori‐positive and 151 ‐negative subjects (247 H. pylori positive and 26 negative prior to any H. pylori cure treatment and 125 H. pylori negative and 11 positive after undergoing H. pylori cure treatment). The breath test procedure was performed under the following conditions: an 8 h fast, mouth washing before and after dosing, administration of 100 mg [13C]‐urea, collection of breath sample in a plastic bag, a baseline and a 20 min sampling point and subject in a sitting position. Delta‐13C at the 20 min sampling point in H. pylori‐positive and ‐negative subjects was 31.0 ± 1.25 and 1.6 ± 0.11%o, respectively. Although the mean Δ13C value was greatest in duodenal ulcer or ulcer scar patients, there were no significant differences among mean Δ13C values in the various diseases. From Receiver Operator Characteristic curves and calculation of accuracy of the test, a cut‐off value of 5.0%o is considered to be appropriate for diagnosis of H. pylori infection, which provides 96.7% specificity and 96.5% sensitivity, suggesting that the [13C]‐urea breath test in the fasting state is as effective in detecting the presence of H. pylori as other reported methods.