Kengo Tokunaga
Kyorin University
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Publication
Featured researches published by Kengo Tokunaga.
Scandinavian Journal of Gastroenterology | 2000
Satoshi Hoshiya; Kazuhiro Watanabe; Kengo Tokunaga; Akifumi Tanaka; Hidehiko Ninomiya; Masao Shingaki; Takeshi Itoh; Shozo Saito; Hitoshi Ishida; Shin Takahashi
Background: Screening patients with columnar metaplasia of the oesophagus for adenocarcinoma is controversial owing to the low cancer incidence and diverging opinions as to whether screening improves the prognosis of these patients. Our aim was to evaluate a screening program for adenocarcinoma in patients with columnar metaplasia in the oesophagus, with focus on cancer incidence and costs. Methods: One hundred and ninety-nine patients with columnar metaplasia of the oesophagus were identified through an endoscopy database, and the original patient records were reviewed. Results: The patients were followed up for 797 years in total and during this time were subjected to 1071 upper gastrointestinal endoscopies. During the screening period 5 patients presented with adenocarcinoma; thus the cancer-incidence was 1 in 159 patient-years. The cost of detecting one cancer was 294,950 SEK (US
Microbiology and Immunology | 2008
Kyoto Imase; Motomichi Takahashi; Akifumi Tanaka; Kengo Tokunaga; Hajime Sugano; Mamoru Tanaka; Hitoshi Ishida; Shigeru Kamiya; Shin'ichi Takahashi
37,815). However, only four of the five patients were suitable for oesophagectomy, and of these, one patient turned out to have an advanced cancer. All patients developing cancer had columnar metaplasia of the oesophagus longer than 3 cm and specialized columnar epithelium (intestinal metaplasia/Barrett oesophagus). Conclusions: Low cancer incidence, high costs, and the doubtful prognosis for the patients with identified cancer question the benefits and cost-effectiveness of cancer screening among patients with columnar metaplasia in the oesophagus.Since clarithromycin is expected to be widely used to treat Helicobacter pylori infection in the near future, it is important to investigate the relationship between resistance to clarithromycin and the regimens of eradication therapy. We investigated: (1) the usefulness of susceptibility tests prior to eradication therapy, and (2) the rate of acquisition of H. pylori resistance to clarithromycin after treatment failure. Drug susceptibility tests to clarithromycin and amoxicillin were conducted by Dry Plate Test or E-test. The subjects in the first part of this study included 112 patients with H. pylori infection who received triple therapy with various combinations of drugs, including clarithromycin. The eradication rate in patients with clarithromycin-susceptible H. pylori was significantly higher than that in patients with clarithromycin-resistant H. pylori. The second part of this study included 21 patients in whom H. pylori was not eradicated by triple therapy and 12 patients in whom H. pylori was not eradicated with dual therapy including clarithromycin. Of the 33 patients showing non-eradication, 90.9% of those treated with dual therapy and 35.7% of those treated with triple therapy acquired secondary resistance of H. pylori to clarithromycin. We conclude that it is important to conduct drug susceptibility tests prior to treatment of H. pylori infection. Since the incidence of acquiring clarithromycin resistance was significantly higher in the patients showing non-eradication, it is important to choose a regimen with a higher eradication rate, such as triple therapy.Abstract: Since clarithromycin is expected to be widely used to treat Helicobacter pylori infection in the near future, it is important to investigate the relationship between resistance to clarithromycin and the regimens of eradication therapy. We investigated: (1) the usefulness of susceptibility tests prior to eradication therapy, and (2) the rate of acquisition of H. pylori resistance to clarithromycin after treatment failure. Drug susceptibility tests to clarithromycin and amoxicillin were conducted by Dry Plate Test or E-test. The subjects in the first part of this study included 112 patients with H. pylori infection who received triple therapy with various combinations of drugs, including clarithromycin. The eradication rate in patients with clarithromycin-susceptible H. pylori was significantly higher than that in patients with clarithromycin-resistant H. pylori. The second part of this study included 21 patients in whom H. pylori was not eradicated by triple therapy and 12 patients in whom H. pylori was not eradicated with dual therapy including clarithromycin. Of the 33 patients showing non-eradication, 90.9% of those treated with dual therapy and 35.7% of those treated with triple therapy acquired secondary resistance of H. pylori to clarithromycin. We conclude that it is important to conduct drug susceptibility tests prior to treatment of H. pylori infection. Since the incidence of acquiring clarithromycin resistance was significantly higher in the patients showing non-eradication, it is important to choose a regimen with a higher eradication rate, such as triple therapy.BACKGROUND Screening patients with columnar metaplasia of the oesophagus for adenocarcinoma is controversial owing to the low cancer incidence and diverging opinions as to whether screening improves the prognosis of these patients. Our aim was to evaluate a screening program for adenocarcinoma in patients with columnar metaplasia in the oesophagus, with focus on cancer incidence and costs. METHODS One hundred and ninety-nine patients with columnar metaplasia of the oesophagus were identified through an endoscopy database, and the original patient records were reviewed. RESULTS The patients were followed up for 797 years in total and during this time were subjected to 1071 upper gastrointestinal endoscopies. During the screening period 5 patients presented with adenocarcinoma; thus the cancer-incidence was 1 in 159 patient-years. The cost of detecting one cancer was 294,950 SEK (US
Helicobacter | 2006
Takeshi Matsuhisa; Takashi Kawai; Tatsuhiro Masaoka; Hidekazu Suzuki; Masayoshi Ito; Yo Kawamura; Kengo Tokunaga; Masayuki Suzuki; Tetsuya Mine; Shin Takahashi; Nobuhiro Sakaki
37,815). However, only four of the five patients were suitable for oesophagectomy, and of these, one patient turned out to have an advanced cancer. All patients developing cancer had columnar metaplasia of the oesophagus longer than 3 cm and specialized columnar epithelium (intestinal metaplasia/Barrett oesophagus). CONCLUSIONS Low cancer incidence, high costs, and the doubtful prognosis for the patients with identified cancer question the benefits and cost-effectiveness of cancer screening among patients with columnar metaplasia in the oesophagus.
Journal of Gastroenterology and Hepatology | 2014
Takashi Kawai; Shin'ichi Takahashi; Hidekazu Suzuki; Hitoshi Sasaki; Akihito Nagahara; Daisuke Asaoka; Takeshi Matsuhisa; Tatsuhiro Masaoaka; Toshihiro Nishizawa; Masayuki Suzuki; Masayoshi Ito; Naoto Kurihara; Fumio Omata; Shigeaki Mizuno; Akira Torii; Kohei Kawakami; Toshifumi Ohkusa; Kengo Tokunaga; Tetsuya Mine; Nobuhiro Sakaki
Antibiotic associated diarrhea due to human intestinal microbiota abnormalities is a side effect of H. pylori eradication therapy. We examined intestinal microbiota changes during H. pylori eradication therapy and the preventive effect of CBM588 as a probiotic agent. Nineteen patients with gastro‐duodenal ulcer were randomly divided into three groups: group A (without probiotics), group B (with regular doses of CBM588) and group C (with double doses of CBM588). The incidence of diarrhea and soft stools during H. pylori eradication therapy was 43% in group A and 14% in group B, while none of the patients in group C reported diarrhea or soft stools. Both bacterial counts and detection rates of bifidobacteria and/or obligate anaerobe were decreased by eradication therapy. However, bacterial counts of obligate anaerobes in group C were significantly higher than in group A (P < 0.05). Additionally, during eradication therapy C. difficile toxin A was detected in both group A and group B but not in group C.
Journal of Gastroenterology and Hepatology | 2003
Akifumi Tanaka; Kazuhiro Watanabe; Kengo Tokunaga; Satoshi Hoshiya; Kiyoto Imase; Hajime Sugano; Masao Shingaki; Akemi Kai; Takeshi Itoh; Hitoshi Ishida; Shin Takahashi
Background: With the increase in the frequency of clarithromycin‐resistant Helicobacter pylori (H. pylori), there is rising concern about the decline of the eradication rate of this infection following treatment. The Tokyo Hp Study Group examined the eradication rate in response to a second‐line regimen consisting of proton pump inhibitor (PPI), amoxicillin, and metronidazole by conducting a multicenter study in the Tokyo Metropolitan Area.
Helicobacter | 2005
Kazuhiro Watanabe; Akifumi Tanaka; Kyoto Imase; Kengo Tokunaga; Hajime Sugano; Akemi Kai; Hitoshi Ishida; Takeshi Itoh; Shin Takahashi
Helicobacter pylori (H. pylori) infection is a strong risk factor for the development of gastric cancer. In 2013, the Japanese government approved H. pylori eradication therapy in patients with chronic gastritis as well as peptic ulcer. However, the continuing decline in eradication rates for first‐line H. pylori eradication therapies is an urgent problem. In this study, we investigated changes in the first‐line eradication rate from 2001 to 2010.
Helicobacter | 2013
Daisuke Asaoka; Akihito Nagahara; Takeshi Matsuhisa; Shin Takahashi; Kengo Tokunaga; Takashi Kawai; Kohei Kawakami; Hidekazu Suzuki; Masayuki Suzuki; Toshihiro Nishizawa; Naoto Kurihara; Masayoshi Ito; Hitoshi Sasaki; Fumio Omata; Shigeaki Mizuno; Akira Torii; Toshifumi Ohkusa; Tetsuya Mine; Nobuhiro Sakaki
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.
Digestion | 2016
Juntaro Matsuzaki; Ryoma Hayashi; Tetsuo Arakawa; Fumiaki Ueno; Yoshikazu Kinoshita; Takashi Joh; Shin'ichi Takahashi; Yuji Naito; Shin Fukudo; Francis K.L. Chan; Ki Baik Hahm; Udom Kachintorn; Kwong Ming Fock; Ari Fahrial Syam; Abdul Aziz Rani; Jose D. Sollano; Qi Zhu; Yasuhiro Fujiwara; Eiji Kubota; Hiromi Kataoka; Kengo Tokunaga; Kazuhiko Uchiyama; Hidekazu Suzuki
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.
Digestive Diseases and Sciences | 2002
Kazuhiro Watanabe; Satoshi Hoshiya; Kengo Tokunaga; Akifumi Tanaka; Hidehiro Watanabe; Shinya Nagamatsu; Hitoshi Ishida; Shin'ichi Takahashi
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.
Digestion | 2018
Nanae Tsuruoka; Ryuichi Iwakiri; Yasuhisa Sakata; Kazuma Fujimoto; Takeshi Kamiya; Takashi Joh; Kengo Tokunaga; Shin Takahashi; Yoshikazu Kinoshita; Kazuhiko Uchiyama; Yuji Naito; Akihito Nagahara; Toshio Watanabe; Francis K.L. Chan; Ki Baik Hahm; Udom Kachintorn; Kwong Ming Fock; Ari Fahrial Syam; Abdul Aziz Rani; Jose D. Sollano; Qi Zhu
Background: Gastrointestinal endoscopy and Helicobacter pylori(H. pylori) eradication therapy are commonly performed even among the elderly population. The aim of this study was to understand the way endoscopists viewed the application of endoscopy and H. pylori eradication in the elderly of East Asian countries. Methods: Self-administered questionnaires containing 13 questions on endoscopy and H. pylori eradication in the elderly were distributed to major institutions in Japan, South Korea, China, Indonesia, and the Philippines. Results: Two hundred and fifteen endoscopists (111 in Japan, 39 in China, 24 in Korea, 21 in Indonesia, and 20 in the Philippines) participated in this study. In the institutions where these endoscopists were associated, around 50% of patients undergoing endoscopy were above the age of 60 years. The participating endoscopists indicated that the necessity of screening esophagogastroduodenoscopy and colonoscopy was lower in populations aged over 81 than the other age groups. They hesitated to perform therapeutic endoscopy, such as endoscopic submucosal dissection or endoscopic retrograde cholangiopancreatography, more often in patients over 85. They also hesitated to perform H. pylori eradication in patients aged over 81, especially in Japan. Conclusion: Endoscopists had significantly different attitudes regarding the indications for screening or therapeutic endoscopy and H. pylori eradication therapy in younger and elderly populations in East Asian countries.