Kohei Kawakami

Tokyo Medical University, Edo, Tōkyō, Japan

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Publications (14)27.7 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: In Japan, the eradication rate of first-line therapy for Helicobacter pylori (H. pylori) with a proton pump inhibitor (PPI), amoxicillin (AMPC) and clarithromycin (CAM) has been decreasing because of a high prevalence of CAM resistance. A possible decrease of the eradication rate for second-line therapy with a PPI, AMPC and metronidazole (MNZ) is of concern. The aim of this study is to assess the trends in second-line eradication therapy for H. pylori in Japan. MATERIALS AND METHODS: We accumulated data retrospectively on patients administered second-line eradication therapy for Helicobacter pylori with a PPI, AMPC, and MNZ for 1 week after failure of first-line eradication therapy with a PPI, AMPC and CAM at 15 facilities in the Tokyo metropolitan area in Japan from 2007 to 2011. Trends for second-line eradication rates in modified intention-to-treat (ITT) analyses were investigated. Second-line eradication rates were categorized by three PPIs (rabeprazole (RPZ), lansoprazole (LPZ) or omeprazole (OMZ)) and evaluated. RESULTS: We accumulated data on 1373 patients. The overall second-line eradication rate was 92.4%. Second-line eradication rates in 2007, 2008, 2009, 2010 and 2011 were 97.7, 90.6, 94.5, 91.8 and 91.8%, respectively, with no significant trends revealed. Second-line eradication rates categorized by three PPIs for the entire 5-year period were 91.6, 93.4 and 92.4% (RPZ, LPZ and OPZ, respectively) with no significant differences among the three PPIs. CONCLUSIONS: From 2007 to 2011, there were no significant trends in the second-line eradication rates and the rates remained consistently high. From the viewpoint of high prevalence of CAM resistance in Japan, triple therapy with PPI, AMPC and MNZ may be a better strategy for first-line therapy compared to triple therapy with PPI, AMPC and CAM.
    Helicobacter 06/2013; · 3.51 Impact Factor
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    ABSTRACT: Ultrathin transnasal endoscopy, used extensively in Japan, is considered to have inferior image quality and suction performance, and questionable diagnostic performance. So the aim of the present study was to compare the diagnostic performance of white light (WL) examination and non-magnified narrow-band imaging (NBI) examination in screening for esophageal disorders with ultrathin transnasal endoscopy. A prospective case study of 105 consecutive patients screened for upper gastrointestinal disorders at a single clinic in Tokyo Medical University Hospital. All subjects were diagnosed using WL, NBI and Lugol-staining examinations. Areas ≥ 5 mm clearly not a Lugol-staining lesion were defined as esophageal disorders and the rates of detection of the two examination methods (WL vs NBI) were compared. For WL examination, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy (concordance rate) for esophageal disorders were 19.6%, 98.1%, 90.9%, 55.4%, and 59.2%, respectively, versus 60.8% 96.2%, 93.9%, 71.4%, and 78.6% for NBI. A useful level of diagnostic performance for esophageal disorders can be achieved with non-magnified narrow-band NBI ultrathin transnasal endoscopy.
    Journal of Gastroenterology and Hepatology 04/2012; 27 Suppl 3:34-9. · 3.33 Impact Factor
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    ABSTRACT: Helicobacter pylori infection rates are reported to be high in people over the age of 40 years, but are decreasing in younger age groups. A negative correlation has been reported between H. pylori infection and reflux esophagitis (RE). The subjects were 418 patients who underwent esophagogastroduodenoscopy and measurement of serum immunoglobulin G H. pylori antibodies examined as part of their routine health checks. Their mean age was 39.2 +/- 8.3 years (range 22-58). We analyzed the RE findings (Los Angeles classification: A, B, C, D). The total H. pylori infection rate was 33.7% (141/418). By age group, infection rates were 15.7% in the 20-29 years group, 28.0% in the 30-39 group, 34.3% in the 40-49 group and 69.1% in the 50-59 group. The proportion of H. pylori-negative subjects with RE was 23.5% (20-29, 22.9%; 30-39, 31.7%; 40-49, 32.4%; 50-59, 41.7%), significantly higher than that (12.1%) in H. pylori-positive subjects (20-29, 0%; 30-39, 16.7%; 40-49, 12.2%; 50-59, 10.5%). The severity of RE increased with advancing age in H. pylori-positive subjects, but not in H. pylori-negative subjects. In this study, higher rates of RE were seen in H. pylori-negative subjects. It may be, however, that the presence of H. pylori infection influences the progression of RE.
    Journal of Gastroenterology and Hepatology 05/2010; 25 Suppl 1:S80-5. · 3.33 Impact Factor
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    ABSTRACT: Helicobacter pylori (H. pylori) eradication rates using the PPI/AC regimen (proton pump inhibitor + amoxicillin + clarithromycin) are declining. We trialed tailoring eradication regimens according to clarithromycin (CAM) susceptibility. The subjects were 70 H. pylori positive adults. They were randomly allocated to a tailored group and a control group. In the tailored group, subjects with CAM-sensitive strains were given PPI/AC eradication therapy, and those with CAM-resistant strains were given PPI/AM (metronidazole instead of clarithromycin) therapy. The control group were all given PPI/AC therapy. CAM sensitivity was measured by collecting fecal specimens, and extracting the DNA. The 23S rRNA domain, associated with CAM susceptibility in H. pylori, was amplified using a nested polymerase chain reaction (PCR), and DNA sequencing was used to detect point mutations at A2143G and A2144G. Eradication rates were 94.3% in the tailored group and 71.4% in the control group. In particular, the eradication rate was 100% for CAM-resistant strains in the tailored group. In Japan, where CAM-resistant H. pylori strains are expected to continue to increase, tailored eradication therapy according to CAM sensitivity will be of benefit.
    Journal of Gastroenterology and Hepatology 01/2009; 23 Suppl 2:S171-4. · 3.33 Impact Factor
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    ABSTRACT: We used transnasal ultrathin esophagogastroduodenoscopy (UT-EGD) to simultaneously perform realtime esophageal manometry and observe esophageal peristalsis. The subjects were 22 healthy volunteers and 10 patients with proton-pump inhibitor (PPI) dependent gastroesophageal reflux disease (GERD). We induced the primary peristaltic wave associated with swallowing and observed it endoscopically in the lower esophagus, at the same time measuring the intraesophageal pressure using a manometry catheter. The mean primary peristaltic amplitude associated with swallowing was 65.6+/-47.4 mmHg in the volunteer group, and 28.0+/-25.6 mmHg in the GERD group. Although peristalsis was observed endoscopically in the GERD group, in some cases incomplete peristalsis left a small but definite lumen and in these subjects, the primary peristaltic wave was almost flat. The use of an ultrathin transnasal endoscope makes possible simultaneous manometry and endoscopic observation of the esophagus. This combination should prove useful in the evaluation of esophageal peristaltic function, such as in the diagnosing of GERD.
    Journal of Gastroenterology and Hepatology 01/2009; 23 Suppl 2:S181-5. · 3.33 Impact Factor
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    ABSTRACT: Diagnostic methods for Helicobacter pylori (H. pylori) infection can be divided into invasive endoscopic methods and non-invasive methods. A typical and widely used non-invasive method is the 13C urea breath test (UBT). In this study, the possibility of a correlation between pre-treatment UBT values with H. pylori antimicrobial resistance is investigated. The subjects were 119 consecutive patients who attended this hospital for H. pylori testing. Average age was 47.5 +/- 13.2 years, with a male:female ratio of 2.05:1. The diagnosis was gastric ulcer in 43 subjects, duodenal ulcer in 27, gastroduodenal ulcer in 21 and chronic gastritis in 28. Subjects underwent UBT as well as upper gastrointestinal endoscopy (UGITE). The diagnosis of H. pylori infection was examined by the results of culture, histological examination and the rapid urease test (RUT). The mean inhibitory concentration (MIC) was determined for each antimicrobial agent in the bacterial isolates that could be cultured. In this study, the sensitivity and specificity were excellent at 97.0% and 100% with a cut-off point of 3.5 per thousand for UBT respectively. Clarithromycin resistance was more common in the group with high UBT values. No correlation at all was seen between UBT values and metronidazole, sparafloxacin, cefaclor and amoxicillin susceptibility. It is possible that UBT values also tend to be higher in cases of CAM resistance.
    Hepato-gastroenterology 01/2008; 55(82-83):786-90. · 0.77 Impact Factor
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    ABSTRACT: In Japan, eradication regimens consisting of a proton pump inhibitor (PPI) + amoxicillin (AMPC) + clarithromycin (CAM) (PPI/AC) for 1 week have been conducted. In the present study, we assessed the eradication rates following treatment with low doses of various PPIs. 135 patients were divided randomly into one of three 7-day regimens: (i) omeprazole (OPZ) 20 mg/day + AMPC 1500 mg/day + CAM 600 mg/day (OAC); (ii) lansoprazole (LPZ) 30 mg + AMPC 1500 mg/day + CAM 600 mg/day (LAC); and (iii) rabeprazole (RPZ) 10mg/day + AMPC 1500 mg/ day + CAM 600 mg/day (RAC). The genetic polymorphism of CYP2C19 was also examined. The eradication rates according to the treatment regimen were as follows: 69.9% (31/45) for OAC, 62.2% (28/45) for LAC, and 71.1% (32/45) for RPZ. No significant differences were found among the regimens. Moreover, eradication rates, according to CYP2C19 phenotype (homozygous extensive metabolizer (EM), heterozygous EM, and poor metabolizer) were: 68.6% (35/51), 77.4% (41/53), and 82.4% (14/17), respectively. In PPI/AC therapy, the eradication rate for each low-dose PPI was 60-70%, which is low. Based on previous reports, it is considered that doses greater than 40 mg/day OPZ, 60 mg/day LPZ, and 20 mg/day RPZ are required.
    Hepato-gastroenterology 04/2007; 54(74):649-54. · 0.77 Impact Factor
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    ABSTRACT: Transnasal esophagogastroduodenoscopy (EGD) is reported to be more pleasant than conventional transoral EGD. In this study, we compared the hemodynamic effects of transnasal and transoral EGD. The subjects were 120 patients with upper gastrointestinal conditions. Transnasal and transoral EGD were performed on 60 subjects each. Oxygen saturation, heart rate and blood pressure were monitored. Subjects were also asked for their condition with each EGD. VAS scores for discomfort at the insertion, and for trouble breathing and nausea during the procedure, were significantly lower for transnasal than for transoral EGD. A significant increase in the heart rate and significant decrease in oxygen saturation were seen only in the transoral group during EGD. The double product (heart rate x systolic blood pressure) was also significantly increased only in the transoral group. No significant changes were seen in the transnasal EGD. Double product has been reported to correlate with myocardial oxygen consumption. Transnasal EGD is a safe technique, and is not only less stressful to patients, but also has fewer hemodynamic effects than the transoral method.
    Hepato-gastroenterology 01/2007; 54(75):770-4. · 0.77 Impact Factor
  • Journal of Clinical Biochemistry and Nutrition - J CLIN BIOCHEM NUTR. 01/2006; 38(1):39-43.
  • Journal of Clinical Biochemistry and Nutrition - J CLIN BIOCHEM NUTR. 01/2006; 38(2):73-76.
  • Gastrointestinal Endoscopy 04/2005; 61(5). · 5.21 Impact Factor
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    ABSTRACT: Background: Helicobacter pylori causes chronic gastritis and is also associated with many other gastrointestinal diseases. The incidence of gastric cancer is thought to vary according to the degree and topography of chronic gastritis. Histological findings of specimens obtained at endoscopy are therefore important. In the present study, we investigated the correlation between these histological findings and serum pepsinogen (PG) levels.Methods: Helicobacter pylori eradication therapy was conducted in 100 H. pylori-positive patients. Endoscopies were performed prior to, and 2 months after, eradication therapy; gastric mucosal biopsies were taken from the antrum and corpus. Helicobacter pylori infection was diagnosed using the rapid urease test, culture and histology. Using the Updated Sydney System, histological findings of inflammation, activity, atrophy and intestinal metaplasia were each graded. Blood was taken on the same two occasions for determination of serum levels of PG I and II.Results:  Levels of PG I were highest in association with antrum-predominant gastritis (APG), followed in order by pangastritis (PAN) and corpus-predominant gastritis (CPG), with a significant difference between APG and CPG. No correlations were seen between PG II levels and gastritis topography. Examination of the relationship between PG levels and histological findings revealed significant correlations between PG I levels after eradication atrophy and intestinal metaplasia in the gastric corpus. No significant correlations were seen between PG II levels and before or after eradication histological findings.Conclusion:  Our results indicate that serum PG levels may be a useful indicator of before-eradication gastritis topography and after-eradication gastric atrophy in the gastric corpus.
    Digestive Endoscopy 03/2004; 16(2):122 - 128. · 1.61 Impact Factor
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    ABSTRACT: Serological antibody test have been widely performed to detect the presence of H. pylori, but they have not been used to evaluate the status of H. pylori after eradication. In this study we evaluated the diagnostic accuracy of a new serological test kit (E-plate) after eradication. Eradication of H. pylori was performed in 100 patients by proton pump inhibitor (PPI)+amoxicillin (AMPC)+clarithromycin (CAM) or PPI+AMPC therapy. Evaluation of H. pylori was done by culture, histology and rapid urease test before, and 8 weeks after, the treatment. Serological tests were also performed before and after treatment using the E plate. Cure was defined as no evidence of H. pylori at 8 weeks after the treatment. Receiver operating characteristic (ROC) analysis was performed to determine the ideal cut-off value for percentage change in the serological test. Success was obtained in 73 patients, failure in 20 patients and there were 7 dropouts. Serological test value was significantly decreased after treatment (44.3 +/- 29.6 U/ ml) compared to before treatment (94.8 +/- 73.2 U/ml) in the successful cases. In contrast, those with no significant change after treatment (62.7 +/- 31.3 U/ml) compared to before treatment (72.9 +/- 47.7 U/ml) were considered as failure cases. ROC analysis revealed that cut-off values of a 20%, 30%, and 40% decrease on E plate result yielded a sensitivity of 95.5%, 92.4%, 71.2% and a specificity of 73.3%, 84.2%, 94.7%, respectively. The new E plate serological test kit for H. pylori was useful for distinguishing success from failure 8 weeks after completion of eradication therapy for H. pylori.
    Internal Medicine 11/2002; 41(10):780-3. · 0.97 Impact Factor
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    ABSTRACT: Decreased bone mineral density is a complication to which we should always pay attention in the treatment of Crohn's disease (CD). However, there is still no clear consensus with regard to evaluation methods and the appropriate observation period for its detection. In the present study, we measured the bone mineral density of 30 CD patients who were treated at the outpatient clinic of our institution and investigated its relationship with various clinical characteristics including sex, age, duration of illness, history of enterectomy, total steroid consumption, body weight, and body mass index (BMI) and with bone metabolism markers. A decreased bone mineral density was detected in 9 patients (30%). The bone mineral density did not correlate with total steroid consumption, but showed a negative correlation with the Crohn's disease activity index (CDAI).When bone metabolism markers were investigated, the bone mineral density showed a negative correlation with Glu-osteocalcin (Glu-OC) and serum type I collagen cross-linked N-telopeptide (NTx) in patients with a low bone mineral density. Based on these results, the decrease of bone mineral density in CD patients was considered to the underlying disease itself. Therefore, control of disease activity is very important in CD patients, and periodic measurement of bone mineral density in combination with bone mineral markers (Glu-OC and serum NTx) may be useful for predicting a decrease of bone mineral density.
    Hepato-gastroenterology 55(88):2116-20. · 0.77 Impact Factor