Toshio Murai

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.

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.

Ammonia, hydrogen peroxide, and monochloramine retard gastric epithelial restoration in rabbit cultured cell model.

Ammonia (NH3), hydrogen peroxide(H2O2) and monochloramine(NH2Cl) produced by Helicobacter pyloriinfection might be responsible for mucosal injury. Theaim of this study was to evaluate the role ofNH3, H2O2, andNH2Cl in the restoration of rabbit primarycultured gastric mucosal cells with a wound repairmodel. Artificial wounds were made in confluentmonolayer gastric epithelial cell sheets by mechanicaldenudation, and changes in the size of the cell-freearea were analyzed quantitatively. Cell proliferation was assessed by bromodeoxyuridine staining. Incontrols, the wound healed within 48 hr. However,mucosal cell repair was inhibited by treatment withNH3, H2O2, andNH2Cl in a dose-dependent manner. These resultsindicate that NH3,H2O2, and NH2Clretarded the wound healing, which included epithelialcell migration and proliferation of gastric mucosa. Therefore, it is suggestedthat NH3, H2O2, andNH2Cl delays the healing process of pepticulcers.

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.

Efficacy of 1 week omeprazole or lansoprazole– amoxycillin–clarithromycin therapy for Helicobacter pylori infection in the Japanese population

Background: The effectiveness of curative therapy for Helicobacter pylori may vary according to the geographic region and patient population, thus the efficacy of each treatment regimen should be determined according to the specific patient population. However, there is no literature available concerning the efficacy of 1 week omeprazole–amoxycillin–clarithromycin (OAC) regimens for the cure of H. pylori infection in Japan.

Effect of Fasting Subjects’ Posture on 13C-Urea Breath Test for Detection of Helicobacter pylori Infection

Although many factors that may affect the 13C‐urea value have been verified, no literature is available regarding the effect of the posture of the patient on the shape of the Δ13C excretion curve. In an effort to contribute to the development of a simple and standard procedure for the 13C‐urea breath test, we investigated whether either the posture of the patient during the procedure or the mouthwash after dosing affects the shape of the Δ13C excretion curve.

The incidence of reflux oesophagitis after cure of Helicobacter pylori in a Japanese population.

Aim: To investigate the incidence of reflux oesophagitis after antibacterial therapy for Helicobacter pylori infection in our patient population.

[13C]-urea breath test for assessment of cure of Helicobacter pylori infection at 1 month after treatment.

Although the [13C]-urea breath test has been reported to provide high specificity and sensitivity, its reliability in determination of cure, including when and how the assessment of cure is made, is not fully established. Here we evaluate the reliability of judgment of cure after 1 month of therapy using the [13C]-urea breath test, including the appropriate time to assess its cure. Our subjects were 199 H. pylori-infected patients (144 men and 55 women; 50.5+/-0.76 years) who underwent cure therapy, took the breath test at 1 month, and underwent both the breath test and invasive tests using endoscopy at 6 months after completion of therapy. Accuracy of the breath test in judgment of cure at 1 month was investigated by comparing the results at 1 month with those at 6 months when cut-off value of the breath test was set at 5 per thousand. Chronologic alterations of the delta13C value were also analyzed in cured patients who underwent the breath test at 1, 3, and 6 months. In 167 (94.9%) of 176 patients whose breath test values were less than 5 per thousand, cure was reconfirmed at 6 months. In 14 (60.9%) of 23 patients whose values were greater than 5 per thousand, cure was demonstrated at 6 months. The mean delta13C values of 33 cured patients who took the breath test at 1 month and repeated the breath test at 3 and 6 months for any reasons were 4.14+/-0.74 per thousand, 2.02+/-0.23 per thousand, and 1.72+/-0.19 per thousand, respectively, and the value at 3 months was significantly smaller than that at 1 month. The reliability of assessment of cure by only the breath test at 1 month was sufficiently high (94.9%) once the patients were judged to be cured. However, because the breath test at 1 month yielded a high false-positive rate and the breath test values at 3 and 6 months were similar, evaluation of cure of H. pylori infection by the [13C]-urea breath test should preferably be done at 3 months after treatment to minimize false-positive results, or the concept of a borderline group should be established for patients with positive but relatively high delta13C values (5-10 per thousand) who repeated the breath test 3 months after treatment.

Effectiveness of Omeprazole-Amoxicillin-Clarithromycin (OAC) Therapy for Helicobacter pylori Infection in a Japanese Population

Background. Omeprazole or lansoprazole, amoxicillin, clarithromycin (PPI/AC) therapy has been reported to provide a high cure rate of H. pylori infection with few adverse effects. Effectiveness of H. pylori therapy may vary among different geographic regions and patient populations. However, there are few reports in Japan as to its effectiveness. We have, therefore, studied the effectiveness of H. pylori therapy in a large group of Japanese patients.