Kazuki Ohta

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.

Polyarteritis nodosa associated with gastric carcinoma and hepatitis B virus infection.

Several cases of polyarteritis nodosa associated with malignant disorders have been reported, most with bone marrow-related tumors. We report polyarteritis nodosa presenting with a fever of unknown origin and muscle weakness that was complicated by advanced gastric carcinoma and hepatitis B virus-positive cirrhosis. Vasculitis was diagnosed after gastrectomy from histologic findings of arterial vasculitis on the resected gastric carcinoma. Our case is so far the second such report of polyarteritis nodosa associated with gastric cancer.

Cellular proliferation and differentiation in rat atrophic gastric mucosa induced by N'-methyl-N'-nitro-N-nitrosoguanidine.

It has been demonstrated that mucosal cell proliferation in atrophic gastritis is significantly accelerated, although the dynamics of the cell proliferation and differentiation have not been well characterized. We sequentially analyzed the markers of proliferation and differentiation of rat atrophic gastritis induced by MNNG. Immunohistochemical staining by anti-BrdU, anti-PCNA, and anti-PDGF-BB antibodies demonstrated that cell proliferation in atrophic gastritis was accelerated not only in the parenchymal tissue but also in the mesenchymal tissue. Expression of a gap junction protein (connexin 32), which is a marker for differentiation of epithelial cells, was reduced during the progression of atrophy. Some apoptotic cells were observed in the lower to middle third of the atrophic mucosa, whereas apoptotic cells were rarely seen in normal mucosa, which suggests that apoptosis in these parts of the mucosa may be related to the occurrence of mucosal atrophy.

A case of pneumatosis cystoides intestinalis associated with ulcerative colitis

Pneumatosis cystoides intestinalis (PCI) is associated with various diseases, but rarely with inflammatory bowel disease. We describe a rare case of PCI associated with ulcerative colitis. The patient was a 30-year-old man with ulcerative colitis (UC), which was in remission under immunomodulator therapy. Colonoscopic examination around 2 years after a diagnosis of UC revealed multiple hemispherical submucosal tumors (SMT) in the ascending colon and hepatic flexure, with erosion and disappearance of vascular network patterns in the rectum. PCI was diagnosed from the result of colonoscopic examination and computed tomography, and had not changed on colonoscopic examination 2 months later, without any treatment.