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Dive into the research topics where Masaki Katsurahara is active.

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Featured researches published by Masaki Katsurahara.


Helicobacter | 2009

Annual Change of Primary Resistance to Clarithromycin among Helicobacter pylori Isolates from 1996 through 2008 in Japan

Noriyuki Horiki; Fumio Omata; Masayo Uemura; Shoko Suzuki; Naoki Ishii; Yusuke Iizuka; Katsuyuki Fukuda; Yoshiyuki Fujita; Masaki Katsurahara; Toshiyuki Ito; Gabazza Esteban Cesar; Ichiro Imoto; Yoshiyuki Takei

Background:  Recent studies have shown that the combination of proton pump inhibitor, amoxicillin and clarithromycin is one of the best choices for Helicobacter pylori eradication therapy. However, increasing number of cases of H. pylori infection showing resistance to clarithromycin therapy has been reported and this is currently the main cause of eradication failure. We investigated the annual changes of the antimicrobial susceptibility to clarithromycin, amoxicillin and minocycline during a period of 12 years in Japan.


Journal of Gastroenterology and Hepatology | 2009

Ease of early gastric cancer demarcation recognition: A comparison of four magnifying endoscopy methods

Shigenori Kadowaki; Kyosuke Tanaka; Hideki Toyoda; Ryo Kosaka; Ichiro Imoto; Yasuhiko Hamada; Masaki Katsurahara; Hiroyuki Inoue; Masatoshi Aoki; Tomohiro Noda; Tomomi Yamada; Yoshiyuki Takei; Naoyuki Katayama

Background and Aim:  Various techniques using magnifying endoscopy (ME) have been developed to enhance images of early gastric cancer (EGC) demarcations, which are often obscure. We investigated four ME methods to determine which is most effective in enhancing the recognition of EGC demarcations: conventional ME (CME), ME with narrow band imaging (NBI‐ME), enhanced‐magnification endoscopy with acetic acid (EME), and ME with NBI and acetic acid (NBI‐EME).


Helicobacter | 2009

Reactive nitrogen species mediate DNA damage in Helicobacter pylori-infected gastric mucosa.

Masaki Katsurahara; Yoshinao Kobayashi; Motoh Iwasa; Ning Ma; Hiroyuki Inoue; Naoki Fujita; Kyosuke Tanaka; Noriyuki Horiki; Esteban C. Gabazza; Yoshiyuki Takei

Background:  Reactive oxygen species (ROS) and reactive nitrogen species (RNS) can play an important role in cellular injury and carcinogenesis of gastric epithelial cells infected with Helicobacter pylori. 8‐OH‐deoxy guanosine (8‐OHdG) and 8‐nitroguanine (8‐NG) are markers for ROS‐ and RNS‐mediated DNA oxidation, respectively. In this study, RNS‐mediated DNA damage in gastric mucosa was observed directly using a newly developed antibody to 8‐NG to clarify how H. pylori infection causes nitrative DNA damage to gastric epithelial cells.


Medicine | 2015

Second and Third-look Endoscopy for the Prevention of Post-ESD Bleeding

Shunsuke Tano; Noriyuki Horiki; Fumio Omata; Kyosuke Tanaka; Yasuhiko Hamada; Masaki Katsurahara; K. Ninomiya; Kenichiro Nishikawa; Keiichiro Nojiri; Reiko Yamada; Hiroyuki Inoue; Esteban C. Gabazza; Naoyuki Katayama; Yoshiyuki Takei

AbstractThe efficacy of 2nd-look esophagogastroduodenoscopy (EGD) with endoscopic hemostatic therapy (EHT) for the prevention of postendoscopic submucosal dissection (ESD) clinical bleeding remains controversial. The aim of this study was to estimate post-ESD bleeding rate using 2nd and 3rd-look strategy, and to determine risk factors for clinical bleeding, and for EHT at 2nd and 3rd-look EGDs.Three hundred forty-four consecutive patients with early gastric cancer or adenoma underwent ESD from January 2006 through March 2012. Second and 3rd-look EGDs were performed on day 1 (D1) and day 7 (D7), respectively, with EHT as needed.Post-ESD clinical bleeding rate was 2.6% (95% confidence interval [CI] 1.2%–4.9%). For clinical bleeding, adjusted odds ratios (ORs) for age <65 years and antithrombotic drug uses were 4.40 (95% CI 1.07–19.93) and 7.34 (95% CI 1.80–32.48), respectively. For D1 EHT, adjusted ORs of tumor location in the lower part of the stomach and maximum tumor diameter ≥60 mm were 2.16 (95% CI 1.35–3.51) and 2.20 (95% CI 1.05–4.98), respectively. For D7 EHT, adjusted OR of D1 EHT was 4.65 (95% CI 1.56–20.0).Post-ESD clinical bleeding rate was relatively low using 2nd and 3rd-look strategy. Age <65 years and antithrombotic drug use are significant risk factors for clinical bleeding. Regarding EHT, tumor location in the lower part of the stomach and maximum diameter of resected specimen ≥60 mm are significant predictors for D1 EHT. D1 EHT in turn is a significant risk factor for D7 EHT. The efficacy of sequential strategy for preventing post-ESD bleeding is promising.


Asian Journal of Endoscopic Surgery | 2013

Single-incision laparoscopic and endoscopic cooperative surgery for gastrointestinal stromal tumor arising from the duodenum.

Masaki Ohi; Hiromi Yasuda; Yoshito Ishino; Masaki Katsurahara; Susumu Saigusa; Kyosuke Tanaka; Koji Tanaka; Yasuhiko Mohri; Yasuhiro Inoue; Keiichi Uchida; Masato Kusunoki

We report a case involving a minimally invasive single‐incision laparoscopic and endoscopic cooperative local excision of a duodenal gastrointestinal stromal tumor. A 59‐year‐old man presented with a 35‐mm lesion located in the second portion of the duodenum. A local resection was performed via single‐incision laparoscopic and endoscopic cooperative surgery. Intraluminal endoscopic dissection of the duodenal mucosa and submucosa was performed circumferentially around the tumor. The resection was then completed by laparoscopic dissection of the seromuscular layer around the tumor. The tumor was retrieved laparoscopically. After confirming that the resection achieved clear surgical margins, we closed the duodenal wall with a laparoscopic stapling device. There were no postoperative complications, including stenosis. Single‐incision laparoscopic and endoscopic cooperative surgery can be safely and effectively performed for a duodenal submucosal tumor.


European Journal of Gastroenterology & Hepatology | 2012

Usefulness of endoscopic submucosal dissection for the treatment of rectal carcinoid tumors.

Yasuhiko Hamada; Kyosuke Tanaka; Shunsuke Tano; Masaki Katsurahara; Ryo Kosaka; Tomohiro Noda; Masatoshi Aoki; Hideki Toyoda; Yoshiyuki Takei; Naoyuki Katayama

Background and aim Various techniques of endoscopy have been developed to treat rectal carcinoids. This retrospective study aimed to evaluate the feasibility and efficacy of endoscopic submucosal dissection for the treatment of rectal carcinoids smaller than 10 mm in diameter. Patients and methods A total of 18 consecutive patients were enrolled with 20 carcinoid tumors that had the following characteristics: the diagnosis of a rectal carcinoid smaller than 10 mm, no endoscopic evidence of muscularis propria invasion, and no evidence of lymph node or distant metastasis (11 men and seven women; median age, 69 years; median tumor size, 4 mm). Tumors were resected by endoscopic submucosal dissection with a needle knife and a hook knife. After marking, a one-third to one-half circumferential mucosal incision was made, and subsequently, the submucosa under the lesion was exfoliated. After the submucosa under the tumor was exfoliated, the residual mucosa was incised and the tumor was removed. Complete resection, complication rates, and operation time were evaluated. Results Complete resection was achieved in all cases (100%) without complications. The mean operation time was 34.2 min, which was acceptable in clinical practice. Conclusion Endoscopic submucosal dissection with the strategy described above is feasible and efficacious for selected patients with a rectal carcin-oid smaller than 10 mm.


Digestive Endoscopy | 2008

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR EARLY GASTRIC CANCER USING MAGNIFYING ENDOSCOPY WITH A COMBINATION OF NARROW BAND IMAGING AND ACETIC ACID INSTILLATION

Kyosuke Tanaka; Hideki Toyoda; Yasuhiko Hamada; Masatoshi Aoki; Ryo Kosaka; Tomohiro Noda; Masaki Katsurahara; Hiroyuki Inoue; Ichiro Imoto; Yoshiyuki Takei

Demarcation of early gastric cancers is sometimes unclear. Enhanced‐magnification endoscopy with acetic acid instillation and magnifying endoscopy with a narrow band imaging (NBI) system have been useful for recognition of demarcation of early gastric cancers. We report a patient with early gastric cancer who underwent a successful endoscopic submucosal dissection (ESD) by magnifying endoscopy with the combined use of NBI and acetic acid instillation. A 72‐year‐old man with early gastric cancer underwent ESD. Demarcation of the lesion was not clear, but magnifying endoscopy using the combination of NBI and acetic acid clearly revealed the demarcation. ESD was carried out after spots were marked circumferentially. We identified the positional relation between the demarcation and all markings. Resection of the lesion was on the outside of the markings. Histopathologically, the lesion was diagnosed as a well‐differentiated adenocarcinoma limited to the mucosa. The margins were carcinoma free. Magnifying endoscopy combining the use of NBI with acetic acid instillation is simple and helpful for identifying the demarcation of early gastric cancer. This method may be useful in increasing the rate of complete resection by ESD for early gastric cancer.


Journal of Infection and Chemotherapy | 2015

Endoscopic findings and lesion distribution in amebic colitis

Noriyuki Horiki; Keiichi Furukawa; Takashi Kitade; Takashi Sakuno; Masaki Katsurahara; Tetsuro Harada; Shunsuke Tano; Reiko Yamada; Yasuhiko Hamada; Hiroyuki Inoue; Kyosuke Tanaka; Esteban C. Gabazza; Naoki Ishii; Katsuyuki Fukuda; Fumio Omata; Yoshiyuki Fujita; Hiroshi Tachibana; Yoshiyuki Takei

A retrospective cohort study was conducted in 55 symptomatic patients with amebic colitis that visited at St. Lukes International Hospital and Mie University Hospital from 1994 through 2013. To diagnose amebic colitis, 40 patients underwent total colonoscopy within 1 week after hospital visiting and before receiving any treatment. The percentage of characteristic endoscopic findings of amebic colitis including discrete ulcers or erosions with white or yellow exudates were 0% in terminal ileum, 93% in cecum, 28% in ascending, 25% in transverse, 15% in descending, 20% in sigmoid colon and 45% in rectum. The rectal lesions in 55% of patients with amebic colitis were nonspecific. The trophozoite identification rate by direct smear of intestinal tract washings performed during colonoscopy was 88%. The protozoan identification rate was 70% in biopsy specimens taken from the periphery of the characteristic discrete ulcers. Total colonoscopy should be considered for the diagnosis of amebic colitis.


Internal Medicine | 2015

Usefulness of Small Intestinal Endoscopy in a Case of Adult-onset Familial Mediterranean Fever Associated with Jejunoileitis

Takashi Kitade; Noriyuki Horiki; Masaki Katsurahara; Toshiaki Totoki; Tetsuro Harada; Shunsuke Tano; Reiko Yamada; Yasuhiko Hamada; Hiroyuki Inoue; Kyosuke Tanaka; Esteban C. Gabazza; Hiroyuki Hayashi; Masanori Tanaka; Yoshiyuki Takei

A 66-year-old Japanese man consulted our institution due to paroxysmal and repetitive bouts of fever and abdominal pain that had persisted for more than one week. Capsule and double-balloon endoscopy (DBE) showed petal-shaped mucosal redness with white hemming in the jejunum and ileum, and histopathology of the biopsy specimens revealed villous atrophy and cryptitis with extensive severe neutrophil infiltration. A genetic examination disclosed compound heterozygous MEFV mutations (E84K, P369S), and familial Mediterranean fever was diagnosed. Treatment with colchicine and infliximab was very effective in inducing the complete disappearance of symptoms and normalization of the endoscopic findings. To the best of our knowledge, this is the first report to describe the findings of small intestinal endoscopic images obtained using capsule and DBE.


Surgical Endoscopy and Other Interventional Techniques | 2012

Magnifying endoscopy for diagnosis of residual/local recurrent gastric neoplasms after previous endoscopic treatment

Ryo Kosaka; Kyosuke Tanaka; Shunsuke Tano; R. Takayama; Kenichiro Nishikawa; Yasuhiko Hamada; Hideki Toyoda; K. Ninomiya; Masaki Katsurahara; Hiroyuki Inoue; Noriyuki Horiki; Naoyuki Katayama; Yoshiyuki Takei

BackgroundIncomplete resection of gastric neoplasms by endoscopic treatment could lead to residual/local recurrence, which may be difficult to identify. This study aimed to evaluate the usefulness of magnifying endoscopy for identifying and demarcating residual/local recurrent gastric neoplasms after endoscopic treatment.MethodsBetween December 2004 and November 2010, magnifying endoscopy was performed in 15 patients with residual/local recurrent gastric neoplasms. All patients underwent conventional magnifying endoscopy (CME) and enhanced-magnification endoscopy with acetic acid instillation (EME) after conventional endoscopy (CE). Eleven patients additionally underwent magnifying endoscopy using narrow-band imaging (NBI-ME) and a combination of narrow-band imaging and acetic acid instillation (NBI-EME). For each procedure, it was recorded whether the location and circumferential demarcation of the lesions were identified. All lesions were resected by endoscopic submucosal dissection.ResultsEleven lesions were identified using CE. However, two and four additional lesions were identified using CME and EME, respectively. In 11 cases, NBI-ME and NBI-EME were performed and all lesions were identified. Three lesions, which were identified by CME, were not demarcated circumferentially. All 15 lesions were well demarcated by EME and 11 by NBI-ME and NBI-EME. Of the resected specimens, histopathology indicated that ten lesions were differentiated tubular adenocarcinomas and five lesions were adenomas. The histopathological diagnosis of the location and demarcation of all neoplasms corresponded to endoscopic findings.ConclusionsMagnifying endoscopy techniques (CME, EME, NBI-ME, and NBI-EME) may be useful for identifying and demarcating residual/local recurrent gastric neoplasms after previous endoscopic treatment.

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