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Featured researches published by Gen Tohda.


Surgical Endoscopy and Other Interventional Techniques | 2008

Clinical evaluation and management of caustic injury in the upper gastrointestinal tract in 95 adult patients in an urban medical center

Gen Tohda; Choichi Sugawa; Christopher P. Gayer; Akiko Chino; Timothy McGuire; Charles E. Lucas

BackgroundCaustic ingestion causes a wide spectrum of injuries; appropriate treatment varies according to the severity and extent of the injury. This retrospective study of adult patients with caustic injury presents the endoscopic findings, treatment regimen, and clinical outcome.MethodsOver a 28-year period, 95 consecutive adult patients admitted to an urban emergency hospital for ingestion of caustic materials were studied. Each patient underwent early endoscopy and the injury was graded for severity. There were 61 men and 34 women with an average age of 37.2 years (range 17 to 81). Ingestion was due to a suicide attempt in 49 patients and accidental in 46 patients.ResultsTen patients showed no mucosal damage. The remaining 85 patients had grade I superficial injury in 47 patients, grade II moderate injury in 25 patients, and deep grade III injury in 13 patients. The ingestion of strong acid or strong alkali often produced deep grade III changes while bleach, detergent, ammonia or other substances usually caused grade I injury. Operative interventions were required for 11 patients with grade III injury and 6 patients with grade II injury. Endoscopic grading was predictive for the onset of complications including late esophageal stricture. There were no complications due to endoscopy; one patient with grade III and multiple comorbidities died from multiple organ failure.ConclusionUpper gastrointestinal endoscopy after caustic ingestion should be performed early to define the extent of injury and guide appropriate therapy. Grade I injuries heal spontaneously. Grade II injuries may be treated conservatively but repeat endoscopy helps define when intervention is needed. Grade III injuries ultimately require surgical intervention.


Digestive Endoscopy | 2005

Evaluation of clinical features of ischemic colitis: Comparison between young and elderly

Gen Tohda; Seiju Higashi; Kenichi Sumiyoshi; Hitoshi Sakumoto; Chikako Kato; Teruyuki Kane

Background: It has been thought that ischemic colitis is caused by vascular and intestinal factors. Although elderly patients with arteriosclerosis are more susceptible to ischemic colitis, many young patients suffering ischemic colitis are also reported. The present study aimed to clarify the relationship between arteriosclerosis and ischemic colitis, and to evaluate various risk factors for ischemic colitis.


World Journal of Gastrointestinal Endoscopy | 2016

Gastric adenocarcinoma of fundic gland type: Endoscopic and clinicopathological features

Gen Tohda; Takeshi Osawa; Yasuyuki Asada; Masaki Dochin; Shintarou Terahata

Gastric adenocarcinoma of fundic gland type (GA-FG) with chief cell differentiation was recently proposed as an extremely rare type of gastric adenocarcinoma. Here, we report 4 cases of GA-FG with chief cell differentiation. Endoscopic features included a submucosal tumor shape or a flat shape, whitish discoloration and dilated vessels on the surface. The tumors were located in the upper or middle third of the stomach. All cases were preoperatively diagnosed as GA-FG by biopsy, and endoscopic submucosal dissection was performed. Resected specimens revealed well-differentiated adenocarcinomas resembling chief cells. Tumor cells were diffusely positive for pepsinogen-I, but partially positive for H(+)/K(+)-ATPase in scattered locations around the tumor margin. Despite the presence of minimal invasion of the carcinoma into the submucosal layer, which was observed in two cases, neither lymphatic nor venous invasion was detected in any of the cases. Finally, all cases showed less aggressive clinical behavior with low grade malignancy.


Hepatology Research | 2012

Case of telangiectatic/inflammatory hepatocellular adenoma arising in a patient with primary sclerosing cholangitis.

Hsu Maylee; Kenichi Harada; Saya Igarashi; Gen Tohda; Makoto Yamamoto; Xiang Shan Ren; Takeshi Osawa; Yasuhiro Hasegawa; Norio Takahashi; Yasuni Nakanuma

Hepatocellular adenomas (HCA) have been recently identified as a heterogeneous group, differing based on genotypic as well as morphological characteristics. HCA are most frequently found in women on oral contraception. A type of HCA, inflammatory HCA, is also known as telangiectatic HCA and was previously referred to as telangiectatic focal nodular hyperplasia. We present the first case of HCA arising from the liver with primary sclerosing cholangitis (PSC). This case is a 30‐year‐old man with a past medical history of PSC, ulcerative colitis and diabetes mellitus. A routine ultrasonography for PSC detected the gradually enlarged intrahepatic mass. Liver biopsy could reveal the diagnosis of telangiectatic/ inflammatory HCA by morphological and immunohistochemical analyses. Partial hepatectomy was performed and the resected liver was pathologically diagnosed as the telangiectatic/inflammatory HCA arising in PSC. This is the first case report of such an association and here we review the current developments and published work of this rare tumor and the association with an activated inflammatory related tumorogenic pathway and PSC.


World Journal of Gastrointestinal Endoscopy | 2018

Management of endoscopic biliary stenting for choledocholithiasis: Evaluation of stent-exchange intervals

Gen Tohda; Masaki Dochin

AIM To evaluate the best management of plastic stents in patients with choledocholithiasis who were unfit for endoscopic stone removal or surgery. METHODS Between April 2007 and September 2017, 87 patients (median age 83.7 years) with symptomatic choledocholithiasis were treated with insertion of 7-Fr plastic stents because complete endoscopic stone retrieval was difficult, and their general condition was not suitable for surgery. Seventy of these patients agreed to regular stent management and stent exchange was carried out at every 6 mo (Group A, n = 35) or every 12 mo (Group B, n = 35). The remaining 17 patients did not accept regular stent exchange, and stents were replaced when clinical symptoms appeared (Group C). We evaluated the frequency of biliary complication and stent patency rate during follow-up periods. RESULTS The patency rate of biliary plastic stents was 91.4% at 6 mo (Group A) and 88.6% at 12 mo (Group B), respectively. Acute cholangitis occurred in 2.9% of Group A patients and in 8.6% of Group B patients. In Group C, median stent patency was 16.3 mo, and stent exchange was carried out in 70.6% of cases because of acute cholangitis or obstructive jaundice. Although a high incidence of acute cholangitis occurred, there was no biliary-related mortality. CONCLUSION Plastic stent exchange at 12-mo intervals is considered a safe procedure for patients with choledocholithiasis. Long-term biliary stenting increases biliary complications, but it can be an acceptable option for select patients who are medically unfit for further invasive procedures.


Circulation | 2001

Evidence of Macrophage Foam Cell Formation by Very Low-Density Lipoprotein Receptor Interferon-γ Inhibition of Very Low-Density Lipoprotein Receptor Expression and Foam Cell Formation in Macrophages

Shotaro Kosaka; Sadao Takahashi; Katsuhiko Masamura; Hideo Kanehara; Juro Sakai; Gen Tohda; Eiko Okada; Koji Oida; Tadao Iwasaki; Hiroaki Hattori; Tatsuhiko Kodama; Tokuo Yamamoto; Isamu Miyamori


Acta Gastro-Enterologica Belgica | 2001

A CASE OF MUCOSA ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA IN THE COLON AND RECTUM

Gen Tohda; Chikako Kato; Seijyu Higashi; Shigeyuki Wakahara; Shotaro Kosaka; Hitoshi Sakumoto; Kenichi Sumiyoshi; Keiichi Matsumoto; Teruyuki Kane; Ryoji Kushima


/data/revues/00165107/v63i5/S001651070601073X/ | 2011

Efficacy and Safety of Nurse-Administered Propofol Sedation During Emergency Upper Endoscopy for Gastrointestinal Bleeding: Prospective, Controlled Study

Gen Tohda; Seiju Higashi; Hitoshi Sakumoto; Kenichi Sumiyoshi; Teruyuki Kane


/data/revues/00165107/v61i5/S0016510705007467/ | 2011

Propofol Sedation During Endoscopic Procedures: Safety and Effective Administration by Registered Nurses, Supervised by Endoscopists

Gen Tohda; Seiju Higashi; Hitoshi Sakumoto; Kenichi Sumiyoshi; Teruyuki Kane


Acta Gastro-Enterologica Belgica | 2007

Biofilms and infections including Helicobacter pylori

Choichi Sugawa; Hiromi Ono; Gen Tohda; Michael A. Carron; James M. Coticchia

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Teruyuki Kane

Shiga University of Medical Science

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Hitoshi Sakumoto

Shiga University of Medical Science

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Kenichi Sumiyoshi

Shiga University of Medical Science

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Chikako Kato

Shiga University of Medical Science

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Keiichi Matsumoto

Shiga University of Medical Science

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Shigeyuki Wakahara

Shiga University of Medical Science

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