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Akifumi Tanaka

Publications and source records attributed to Akifumi Tanaka.

11 recordsLinked to original sources
PubMed2006

[Generalization of Helicobacter pylori eradication therapy and its future in Japan].

After official acceptance of eradication therapy for Helicobacter pylori infected peptic ulcer disease in 2000, this treatment has been generalized as ulcer therapy in Japan. In 2003 the consensus statement of the Japanese Society for Helicobacter Research (JSHR) for Helicobacter pylori infection was presented. According to this statement MALT lymphoma was recommended to treat H. pylori infection because of the efficacy of its out come. Atrophic gastritis was also advised to treat H. pylori infection for the purpose of preventing gastric cancer development. The extra alimentary disease such as idiopathic thrombocytopenic purpura was still under evaluation. In diagnostic method the importance of drug susceptibility test is rising because of the increase of drug resistant H. pylori strain in Japan. The false positive case of urea breath test, the accuracy of new Japanese original serology tests and the stool antigen test are also under investigation. The standard regimen of H. pylori eradication therapy in Japan is proton pomp inhibitor (PPI) + amoxicilin (AMPC) + clarithromycin (CAM). The problem of this regimen is the decrease of eradication rate. The reason of this trend might be increase of CAM resistant strain. JSHR recommended a rescue regimen as PPI + AMPC + metronidazole for the patient whose first eradication therapy was unsuccessful result. The eradication of this second line regimen was reported as about 90%.

Amoxicillin↗
PubMed2005

Amoxicillin resistance in Helicobacter pylori: studies from Tokyo, Japan from 1985 to 2003.

BACKGROUND: Previous reports revealed no resistant strains of amoxicillin (AMPC), which is usually used in eradication therapy for H. pylori infection. However, the frequency and evolution of natural AMPC-resistant strains in the Japanese population remains unknown. AIM: To assess the prevalence of H. pylori resistance against AMPC in the Tokyo area, a collection of 648 H. pylori strains isolated from patients with GI diseases from 1985 to 2003 was tested for their sensitivity to AMPC. METHODS: The susceptibility of the strains was assessed by determination of the minimal inhibitory concentration (MIC) using the E-test and/or the Dry-plate method. The susceptibility breakpoints of AMPC for H. pylori were: sensitive (AMPC-S); MIC < 0.04 microg/ml, intermittent resistance (AMPC-I); 0.04-1, resistant (AMPC-R); > 1. RESULTS: No AMPC-R strains were detected in the strains isolated between 1985 and 1996, while the rate of resistance was determined to be 1.1%, 2.1%, 5.4%, 5.6%, 0%, 8.8%, and 1.5% every year, respectively, from 1997 to 2003. The percentage of AMPC-I strains increased from 2000 to 2003. The total eradication rate of H. pylori in the patients who received triple therapy containing AMPC was 81.4% (214/263). Classified as above, the rates of AMPC-S, AMPC-I, and AMPC-R were 84.6%, 77.8%, 25%, respectively. CONCLUSION: H. pylori resistance to AMPC is still rare in Japan, although the percentage of AMPC-I strains has increased over the last 4 years. The frequency of isolation of strains showing true resistance to AMPC may increase in the future, along with an increase in the frequency of isolation of AMPC-I strains.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

[Evaluation of 13C-urea breath test to confirm eradication of Helicobacter pylori].

This study aimed to evaluate the effectiveness of the 13C-urea breath test (UBT) for assessment of Helicobacter pylori eradication after treatment. One hundred twenty six patients were enrolled with 85 receiving proton pomp inhibitor based triple therapy. They were underwent upper gastrointestinal endoscopy with biopsies for diagnosis and assessment of H. pylori infection using culture, histology, rapid urease test (RUT) and 13C-UBT. Assessment of eradication needs to be performed 4 weeks or more after completion of treatment. Breath samples were taken 15 minutes after the ingestion of 100 mg 13C-urea. Breath samples were analyzed on a mass spectrometer system. The gold standard for H. pylori infection was a positive culture or positive histology + positive RUT; negative for infection was defined as negative results of all three biopsy tests. Based on ROC curves, the most appropriate cut-off value for diagnosis of H. pylori infection was identified as 2.5/1000, which provided 96.2% sensitivity, 100% specificity, and 96.8% accuracy as judged by the gold standard. However, when confirming the eradication of H. pylori, it was 3.5/1000, which provides for 100%, 95.8%, and 96.5%, respectively. Ten patients (11.8%) had delta13C values that were 2.5-5.0/1000 4-12 weeks after therapy. Eight patients were considered cured of H. pylori infection, and 2 were considered to still have H. pylori infection following 13C-UBT, serology, and H. pylori specific antigen test. The false-positive rate of 13C-UBT was 9.4% (8/85). When the grey zone of 13C-UBT was set at a level of 2.5 to 5.0/1000 (2.5 > : negative, 5.0 < or = : positive) after eradication therapy, the sensitivity and specificity of 13C-UBT was 100% and 98.4% compared to the gold standard. It was concluded that to avoid false-positive results of 13C-UBT, the grey zone of 13C-UBT needs to be set at a level of 2.5 to 5.0/1000; thus improving the accuracy of test for the assessment of eradication of H. pylori infection.

Adult↗
PubMed2004

[Helicobacter pylori stool antigen test].

In Japan, Helicobacter pylori stool antigen(HpSA) test was opened for diagnosis of H. pylori infection before and after eradication therapy form Nov. 1, 2003. We can use two kinds of HpSA kits, Premier Platinum HpSA(Meridian Bioscience, USA) and Testmate pylori antigen EIA(Wakamoto Pharmaceutical Co., Ltd., Japan). We evaluated the diagnostic accuracy of the HpSA test(Premier Platinum HpSA) compared with diagnosis based on endoscopic biopsy-based methods. In 136 patients, the sensitivity and specificity of the HpSA test before therapy were 98.3% and 95.0%, respectively. In 54 patients, the sensitivity and specificity of the HpSA test after eradication therapy were 90% and 97.7%, respectively. Therefore, it is concluded that the HpSA test is a useful method for the diagnosis of H. pylori infection before and after eradication therapy.

Antigens, Bacterial↗
PubMed2003

Evaluation of Helicobacter pylori stool antigen test before and after eradication therapy.

BACKGROUND AND AIM: The Helicobacter pylori stool antigen (HpSA) test is useful for initial diagnosis of H. pylori infection, but there is disagreement regarding its diagnostic accuracy after eradication therapy. The aim of the present study was to evaluate the diagnostic accuracy of the HpSA test before and after eradication therapy. METHODS: One hundred and thirty-six patients underwent upper gastrointestinal endoscopy with biopsies for the diagnosis of H. pylori infection using culture, histology and the rapid urease test. Fifty-four H. pylori-positive patients were treated with 1-week triple therapy. Six to 10 weeks after the end of therapy, the patients underwent re-endoscopy and received the same biopsy-based methods. In addition, the 13C-urea breath test was performed. The HpSA test was performed before and 6-10 weeks after the end of therapy. In 23 patients, the HpSA test was also performed at the end of therapy. RESULTS: Before therapy, the sensitivity and specificity of the HpSA test was 98.3% (95% confidence interval (CI): 95.9-100%) and 95.0% (95% CI: 75.1-99.9%), respectively. At the end of therapy, the HpSA tests were all negative both for eradication and non-eradication patients. The sensitivity and specificity of the HpSA test after eradication therapy were 90% (95% CI: 55.5-99.7%) and 97.7% (95% CI: 93.3-100%), respectively. CONCLUSIONS: The HpSA test is a useful method for the diagnosis of H. pylori infection before and after eradication therapy.

Adult↗
PubMed2002

Helicobacter pylori and acetylsalicylic acid synergistically accelerate apoptosis via Fas antigen pathway in rabbit gastric epithelial cells.

The mechanism for gastric epithelial cellular apoptosis by both H. pylori and NSAIDs remains unknown. Normal gastric epithelial cells, collected from rabbit stomach, were cultured with viable H. pylori and/or an acetylsalicylic acid for 24 hr as an in vitro model of gastric epithelial cell injury. The Fas antigen expression rate in the gastric epithelial cells was measured using a FACScan. In group E, in which H. pylori inoculation of epithelial cells was followed by treatment with an NSAID, the rate of Fas antigen expression was significantly higher than the rate observed after treatment with either H. pylori or NSAID alone. Despite the fact that drug treatment alone did not significantly increase the Fas expression rate vs control cells. The results suggest that H. pylori and NSAID induce gastric cell injury as apoptosis via the Fas antigen pathway in a synergistic manner and that this effect is particularly strong when NSAID treatment follows H. pylori infection.

Animals↗
PubMed2002

[Ecabet sodium].

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2-Pyridinylmethylsulfinylbenzimidazoles↗