Yasunori Takehira
Nihon University
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Featured researches published by Yasunori Takehira.
CardioVascular and Interventional Radiology | 2002
Toshifumi Nakamura; Ritsuko Hirai; Mutsuo Kitagawa; Yasunori Takehira; Masami Yamada; Katsutoshi Tamakoshi; Yoshimasa Kobayashi; Hirotoshi Nakamura; Masao Kanamori
Purpose: To compare the effectiveness of various means of stenting in patients with biliary obstruction caused by pancreatic cancer in a retrospective analysis. Methods: Sixty-two patients with biliary obstruction due to unresectable pancreatic cancer underwent biliary stenting. On the basis of the findings obtained by percutaneous transhepatic cholangiography (10 patients) and endoscopic retrograde cholangiography (52 patients), the site of obstruction was distal to the hilar confluence, predominantly especially in the middle to lower third of the common bile duct. Polyurethane-covered Wallstents (9 mm in diameter) were inserted in 13 patients, while uncovered Wallstents (10 mm in diameter) were used in 10 patients and plastic stents (10 Fr and 12 Fr) were used in 39 patients. Results: Stenting was successful in 34 patients (87.2%) treated with plastic stents and in 22 patients (95.7%) treated with Wallstents. Effective biliary drainage was achieved in 32 out of 34 patients (94.1%) treated with plastic stents and in 21 out of 22 patients (95.5%) treated with Wallstents. The cumulative patency rate was significantly higher for the uncovered and covered Wallstents compared to plastic stents, but was not significantly higher for covered than for uncovered Wallstents. Stent occlusion occurred in 23 patients (70%; all by clogging) from the plastic stent group, in two patients (22%; by tumor ingrowth) from the uncovered Wallstent group, and in one patient (9%; by clogging) from the covered Wallstent group. The survival rate showed no significant difference among the three stent groups. Conclusion: The Wallstent is effective for long-term palliation in patients with obstruction caused by pancreatic cancer invading the middle to lower part of the common bile duct. The covered Wallstent can prevent tumor ingrowth, a problem with the uncovered Wallstent. However, it may be necessary to take measures to prevent the migration or clogging of covered Wallstents.
CardioVascular and Interventional Radiology | 2000
Toshifumi Nakamura; Mutsuo Kitagawa; Yasunori Takehira; Masami Yamada; Tsunehisa Kawasaki; Hirotoshi Nakamura
Four patients with malignant obstruction of the common bile duct had been treated with uncovered Wallstents and suffered from a reobstruction after 2–13 months (mean 5.3 months). Repeat cholangiography revealed severe stenosis of the stent lumen caused by tumor ingrowth through the mesh. A Wallstent with a self-made polyurethane-cover was inserted through the uncovered stent in these patients. The four patients were followed for 3–13 months (mean 6.3 months) until death. There was good drainage with no evidence of recurrent obstruction in all patients. We conclude that a covered Wallstent may extend patency of stented bile ducts, preventing tumor ingrowth in patients with neoplastic obstruction. Further observations are needed.
Digestive Diseases and Sciences | 2003
Yumiko Honjo; Yoshimasa Kobayashi; Toshifumi Nakamura; Yasunori Takehira; Mutsuo Kitagawa; Yoshito Ikematsu; Takachika Ozawa; Hirotoshi Nakamura
Schwannoma (neurilemoma or neurinoma) rarely develops in the biliary tract. We report here a case of extrahepatic biliary schwannoma found in a 47-yr-old Japanese woman presenting with obstructive jaundice. The radiological imaging studies were suggestive of nonepithelial tumor involving the common bile duct. The patient underwent tumor resection. The tumor extended inward and outward from the wall of the common bile duct in the shape of a dumbbell. The extraductal tumor was solid with microcystic changes, while the intraductal lesion presented cystic changes. Microscopically, the tumor was predominantly composed of spindle-shaped cells with nuclear palisading, and it contained lymphoid aggregates. Immunohistochemically, the tumor cells were positive for S-100 protein. The final diagnosis was benign schwannoma of the common bile duct. The tumor differed from usual soft tissue schwannoma and closely resembled gastrointestinal schwannoma.
CardioVascular and Interventional Radiology | 2000
Toshifumi Nakamura; Mutsuo Kitagawa; Yasunori Takehira; Masami Yamada; Yoshiro Nishiwaki; Hirotoshi Nakamura
A 71-year-old man developed pyloric stenosis caused by gastric cancer. Vomiting and nausea resolved after the insertion of an uncovered Ultraflex stent (length 10 cm, inner diameter 18û23 mm) through a 7-cm-long stenosis, and the patient was able to eat a soft diet. After 6 weeks, stent occlusion occurred due to tumor ingrowth and accumulation of food residue. Endoscopic observation showed a very narrow residual lumen. A covered Ultraflex stent (length 10 cm, inner diameter 18û23 mm) was inserted through the first stent and expanded to its maximum diameter over the next 2 days. The patients vomiting and nausea improved rapidly. He died 6 months after the second stenting procedure, from metastatic tumor spread, having remained free of nausea and vomiting. In this case, a covered metallic stent prevented tumor ingrowth and maintained gastrointestinal patency.
The American Journal of Gastroenterology | 2000
Koki Hirasawa; Masami Yamada; Mutsuo Kitagawa; Yasunori Takehira; Katsutoshi Tamakoshi; Toshifumi Nakamura; Kinya Kawamura; Masahiro Takagi; Binzaburo Murohisa; Takachika Ozawa; Hiroyuki Hanai; Eizo Kaneko
Gastrin producing ovarian tumor is a rare cause of the Zollinger-Ellison syndrome. We report the case of an ovarian carcinoma showing increased plasma gastrin concentration. A 60-yr-old woman presented with epigastric pain and diarrhea. Physical examination showed a large mass in the lower abdomen. Computed tomography revealed a large multilocular ovarian cyst. Upper gastrointestinal endoscopy examination showed multiple ulcerations of the stomach and duodenum. The plasma gastrin level was 1500 pg/ml. No tumors were found in the pancreas and duodenum, and salpingo-oophorectomy was performed. Histologic examination revealed a mucinous tumor of borderline malignant potential. Immunoperoxidase studies for gastrin showed many gastrin-producing cells within the epithelium of the tumor. There have been 11 cases (including our patient) of gastrin-producing ovarian tumor reported in the literature. We review here the relevant literature. Although ovarian gastrinoma is extremely rare, it should be considered as a possible cause of the Zollinger-Ellison syndrome in women.
Gastroenterologia Japonica | 1988
Koichi Kanai; Satoshi Morioka; Takeyuki Nakajima; Hidemasa Ishii; Katsutoshi Tamakoshi; Hiroko Matsuda; Masahiro Matsumoto; Noriaki Mizushima; Yasunori Takehira
SummaryTwelve male patients with chronic hepatitis B were treated by the combination of recombinant human α-interferon and cyanidanol. They received 3 million units of interferon twice a week and 2,250 mg of cyanidanol daily for 24 weeks. Four patients had sustained clinical improvement in which hepatitis B e antigen and DNA polymerase disappeared from sera and aminotransferase activities fell to normal levels. Elevated pretreatment aminotransferases were associated with the response to therapy. Also, decreased number of OKT4-positive cells prior to treatment were observed among responders. Side effects were minimal and all patients tolerated treatment on an outpatient basis.Twice weekly administration of recombinant leukocyte interferon with cyanidanol may be effective in treating chronic hepatitis when patients are appropriately selected.
The American Journal of Gastroenterology | 2000
Koki Hirasawa; Masami Yamada; Mutsuo Kitagawa; Yasunori Takehira; Katsutoshi Tamakoshi; Toshifumi Nakamura; Kinya Kawamura; Masahiro Takagi; Binzaburo Murohisa; Takachika Ozawa; Hiroyuki Hanai; Eizo Kaneko
Gastrin producing ovarian tumor is a rare cause of the Zollinger-Ellison syndrome. We report the case of an ovarian carcinoma showing increased plasma gastrin concentration. A 60-yr-old woman presented with epigastric pain and diarrhea. Physical examination showed a large mass in the lower abdomen. Computed tomography revealed a large multilocular ovarian cyst. Upper gastrointestinal endoscopy examination showed multiple ulcerations of the stomach and duodenum. The plasma gastrin level was 1500 pg/ml. No tumors were found in the pancreas and duodenum, and salpingo-oophorectomy was performed. Histologic examination revealed a mucinous tumor of borderline malignant potential. Immunoperoxidase studies for gastrin showed many gastrin-producing cells within the epithelium of the tumor. There have been 11 cases (including our patient) of gastrin-producing ovarian tumor reported in the literature. We review here the relevant literature. Although ovarian gastrinoma is extremely rare, it should be considered as a possible cause of the Zollinger-Ellison syndrome in women.
Kanzo | 1997
Toshifumi Nakamura; Katsutosi Tamakoshi; Yasunori Takehira; Binzaburo Murohisa; Mutsuo Kitagawa; Masami Yamada; Masahiro Matsushita; Kinya Kawamura; Masahiro Takagi; Takachika Ozawa; Tsunehisa Kawasaki
症例は38歳, 男性. 10歳時, 他院にて糖原病と診断された. 平成6年5月12日, 尿路結石発作のため入院. 保存的治療により症状は消失したが, 腹部超音波検査にて肝腫大と両葉の多発性腫瘍を認めた. 血液検査では高乳酸, 高尿酸, 高ピルビン酸, 高脂血症を認め, 腫瘍マーカーはCA19-9が軽度上昇していた. 画像上, 腫瘍はいずれも低エコーで, 造影CTの早期に辺縁造影効果あり. 逆行性膵胆管造影では, 胆嚢, 肝内胆管第一分枝~総胆管および膵管に異常なし. 他臓器に腫瘍を認めず, 原発性肝腫瘍と考えられた. 腫瘍生検を施行し, 胆管細胞癌と診断した. 非腫瘍部肝組織のGlucose-6-phosphatase活性は低下しており糖原病Ia型であった. 化学療法を施行したが, 癌性腹膜炎を併発し, 当院受診後1年10カ月で死亡した. 糖原病I型は, ときに腺腫の合併を認めることは知られているが, 胆管細胞癌が合併した報告は本症例が最初である.
Internal Medicine | 2001
Yasushi Iwaoka; Masami Yamada; Yasunori Takehira; Kazunori Hanajima; Toshifumi Nakamura; Gou Murohisa; Ritsuko Hirai; Mutsuo Kitagawa
Internal Medicine | 2003
Kazuhito Kawata; Yasunori Takehira; Yoshimasa Kobayashi; Mutsuo Kitagawa; Masami Yamada; Kazunori Hanajima; Gou Murohisa; Motoko Kawamura; Yasushi Iwaoka; Tomohiko Wada; Satoru Morita; Moriya Iwaizumi; Satuki Making