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Dive into the research topics where Takao Okamura is active.

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Featured researches published by Takao Okamura.


Cancer | 1980

Intraoperative radiotherapy for advanced carcinoma of the biliary system

Takeshi Todoroki; Yoji Iwasaki; Takao Okamura; Kazuo Nagoshi; Hideo Asakura; Masayuki Nakano; Tetsuo Inada; Hiroshi Tsunemoto; Yoichiro Umegaki; Akira Nishimura; Masao Nakano; Hiroshi Sato

Since November 1973, intraoperative radiotherapy has been performed on five patients with unresectable, advanced carcinoma of the bile duct at the hepatic hilus and six patients with unresectable carcinoma of the gallbladder. A treatment cone with a diameter ranging from 4–10 cm was directly applied at the lesion. A single dose of 2500–3000 rad with 11 to 20 meV electrons was delivered. In all patients, recanalization of the obstructed bile duct was observed by the postoperative cholangiography. The local efficacy was confirmed histopathologically in eight autopsied materials and a specimen resected 105 days after radiotherapy. Mean survival time of patients with unresectable tumors was 10.9 ± 5.6 (SD) months after this radiotherapy. Intraoperative radiotherapy increased the effectiveness and length of palliation for the unresectable lesion.


Cancer | 1984

Intraoperative radiotherapy for advanced carcinoma of the pancreas.

Akira Nishimura; Masao Nakano; Hiroshi Otsu; Kikuo Nakano; Koyo Iida; Suoh Sakata; Keiichi Iwabuchi; Koshi Maruyama; Michio Kihara; Takao Okamura; Takeshi Todoroki; Yoji Iwasaki

A detailed retrospective analysis of the efficacy of intraoperative radiotherapy (IOR) in advanced carcinoma of the pancreas is presented. During a 10‐year period from 1973 through 1982, 70 patients with advanced carcinoma of the pancreas were treated by multimodal methods, separate or combined therapy of surgery, IOR, and chemotherapy in two different institutions. Among these, 33 patients underwent IOR, mostly combined with additive surgery. A single dose of 20.1 to 40.0 Gy with 8 to 25 meV electrons was delivered through radiation cones ranging from 6 to 10 cm in diameter. Excellent relief was noticed in 50% of the patients who had complained of pain. Among Stage IV patients, a significant difference of survival rate was observed between IOR and control groups (P < 0.05); the mean survival time of the IOR group was 4.6 ± 2.6 (SD) and that of the control group 2.5 ± 1.4 (SD) months. Intraoperative radiotherapy proved to be effective in prolonging the survival of patients with advanced stage of the lesion.


World Journal of Surgery | 1988

The role of intraoperative radiation therapy in the treatment of bile duct cancer

Yoji Iwasaki; Takeshi Todoroki; Katashi Fukao; Kiyoshi Ohara; Takao Okamura; Akira Nishimura

AbstractSince October, 1976, we have treated a total of 81 patients with bile duct cancer. Fifty of these patients had cancer that originated at and/or infiltrated into the main hepatic ducts. Five patients had cancer on the upper to middle portion, 19 on the middle to intrapancreatic bile duct, and the remaining 7 had diffusely involved tumors. Fifty of the 81 patients underwent resections. Of the 50 patients, 33 received curative or noncurative resection alone, 14 were treated by resection plus intraoperative radiotherapy (IORT), and the remaining 3 received postoperative external irradiation. Thirty-one of the 81 patients did not undergo tumor resection. Of these, 6 had IORT and 4 underwent external radiotherapy after bile drainage. The remaining 21 underwent bile drainage alone. Curative resection achieved the best cumulative 5-year survival rate of 59.3%. IORT plus noncurative resection showed a superior 2-year survival rate of 17,1% compared to 9.0% after noncurative resection alone. Only 1 patient treated by IORT plus bile drainage survived more than 2 years and subsequently died at 34 months.nIn the earlier stage of the development of the combination therapy with resection and IORT, severe complications were experienced in 9 patients (so treated), including remarkable obstructive changes of the hepatic arteries. In the later stage, resection plus IORT with a reduced single dose (20 Gy), using a smaller field size (3.7±1.4 cm) and beam energy (7.3±3.0 MeV), did not result in complication and produced 2 long-term survivors among 5 patients. Fractionated external irradiation (30–40 Gy/4–5 weeks) has been added to the IORT recently. These results indicate that noncurative resection plus IORT in combination with external radiation would improve the prognosis of the patient with advanced bile duct cancer.RésuméDepuis octobre 1976, les auteurs ont traité 81 malades porteurs dun cancer biliaire. Cinquante dentre eux présentaient un cancer qui prenait son origine et/ou infiltrait les canaux biliaires principaux dont 5 cancers de la partie haute ou de la partie moyenne de larbre biliaire, 19 de la partie moyenne et de la partie intra-pancréatique, 7 diffus. Cinquante des 81 lésions furent réséqués. Des 50 opérés: 33 furent traités par exérèse isolée à titre curatif ou palliatif, 14 par exérèse et irradiation per-opératoire, 3 par irradiation externe post-opératoire. Trente et un des 81 malades ne subirent pas dexérèse: 6 furent traités par irradiation intra-opératoire, 4 par irradiation externe après mise en place dun drainage biliaire, 21 par simple drainage. La survie à 5 ans fut de 59.3% après exérèse curative. La survie à plus de 2 ans fut de 17.1% après exérèse palliative complétée par irradiation et de 9% après simple exérèse. Un seul malade survécut 34 mois après irradiation opératoire et drainage biliaire.Au début de cette expérience thérapeutique combinant lexérèse et lirradiation opératoire, 9 malades dévelopèrent des complications sévères dues en particulier à lobstruction des artères hépatiques. Ultérieurement en employant une seule dose de 20 grays, un champ dirradiation plus petit (3.7±1.4 cm) et une source plus forte denergie (7.3±3.0 MeV). Ces complications furent évitées et 2 malades sur 5 bénéficièrent dun longue survie. Récemment à lirradiation peropératoire a été ajoutée une irradiation externe fractionnée (30–40 grays/4–5 semaines). Ces résultats démontrent que lexérèse palliative de la tumeur associée à lirradiation interne peropératoire et à lirradiation externe postopératoire est susceptible daméliorer le pronostic du cancer biliaire parvenu à un stade évolutif avancé.ResumenA partir de octubre de 1976, hemos tratado 81 pacientes con cáncer de la vía biliar. Cincuenta de estos pacientes presentaban cáncer que se originaba y/o infiltraba los canales hepáticos principales. Cinco tenían cáncer de la región superior a media, 19 de la región media a la intrahepática, y los restantes 7 presentaban tumores de extensión difusa. Cincuenta de los 81 pacientes fueron sometidos a resección. De los 50, 33 fueron tratados mediante resecciones curativas o no curativas solamente, 14 mediante resección más radioterapia intraoperatoria (RTIO), y los 3 restantes recibieron radioterapia externa postoperatoria. Treinta y uno de 81 pacientes no fueron sometidos a resección. De estos, seis tuvieron RTIO y 4 radioterapia externa después de drenaje biliar. Los 21 restantes tuvieron drenaje biliar solamente. La resección curativa logró la mejor tasa de supervivencia acumulada a 5 años, 59.3%. La RTIO más resección no curativa exhibió una tasa de supervivencia a 2 años de 17.1%, superior a la de 9.0% de los pacientes sometidos a resección solamente. Con la RTIO combinada con drenaje biliar, sólo un paciente sobrevivió más de 2 años y murió a los 34 meses.En la etapa inicial de desarrollo de la terapia combinada de resección y RTIO, se presentaron complicaciones severas en 9 pacientes así tratados, incluyendo alteraciones severas de las arterias hepáticas. En la etapa siguiente, la resección combinada con RTIO de dosis única (20 Gy) utilizando un campo de menor extensión (3.7±1.4 cm) y menor energía (7.3±3.0 MeV) no resultó en complicaciones y produjo 2 supervivencias a largo plazo entre 5 pacientes. Recientemente se ha añadido la irradiación externa fraccionada (30–40 Gy/4–5 semanas) a la RTIO. Los resultados indican que la resección no curativa más RTIO en combinación con irradiación externa podrían mejorar el pronóstico del paciente con cáncer avanzado de la vía biliar.


World Journal of Surgery | 1985

Surgical technique for repair of benign stricture of the bile ducts, preserving the papilla of vater

Takao Okamura; Kazuo Orii; Atsushi Ono; Azusa Ozaki; Yoji Iwasaki

From March 1977 to October 1983, we examined 6 patients with benign bile duct stricture. Four were female and 2 were male, ranging in age from 55 to 69 years. These patients were treated by operative methods in which the papilla of Vater was preserved. These operative methods were end-to-side anastomosis of the bile ducts, repair of the bile duct utilizing a part of the gallbladder or a remnant of the cystic duct, and repair of the bile duct using a patch of jejunal wall. The postoperative observation period is 8 months to 7 years and 4 months. It is our policy to preserve the function of the papilla of Vater when possible because with this method the flow of bile is uninterrupted. We especially recommend a jejunal patch for repair of the bile duct, when no remnant of the cystic duct is available. This method is applied when the bile duct stricture is less than 3 cm long. We have operated on 2 patients with this method and the results have been completely satisfactory.RésuméDe mars 1977, à octobre 1983, les auteurs ont opéré 6 sténoses bénignes des voies biliaires chez 4 femmes et 2 hommes, leur âge étant compris entre 55 et 69 ans. Les techniques opératoires suivies eurent pour but de préserver lintégrité de la papille de Vater. Elles ont consisté en anastomose terminolatérale biliaire, reconstruction du canal biliaire en employant un segment de la vésicule ou le moignon cystique ou encore en utilisant un “patch” jéjunal. Le suivi de ces interventions sétend de 8 mois à 7 ans et 4 mois. La tactique a été de préserver les fonctions de la papille de Vater dans la mesure du possible pour respecter la physiologie biliaire.Les auteurs conseillent davoir recours au patch jéjunal quand un moignon cystique nest pas disponible; cette méthode en fait ne peut être appliquée quen présence dune sténose biliaire dont la longueur est inférieure à 3 cm. Dans 2 cas, où elle été employée elle a donné dexcellents résultats.ResumenEn presencia de estrecheces benignas de los canales biliares los cirujanos generalmente realizan coledoco-yeyunostomía o coledocoduodenostomía como forma de manejo operatorio. Sinembargo, en ocasiones se producen complicaciones indeseables como resultado de estas operaciones, tales como colangitis recurrente, estrecheces de la anastomosis o formación de cálculos intrahepáticos. Con el objeto de evitar este tipo de problemas, una operación que logre la conservación de la papila Vater y de su función viene a significar algo ventajoso.Entre marzo de 1977 y octubre de 1983 tuvimos 6 pacientes con estrecheces biliares benignas. Cuatro eran mujeres y dos hombres, con edades entre 55 y 69 años. Estos pacientes fueron tratados mediante operaciones conservadoras de la papila. Tales operaciones fueron la anastomosis término-lateral de los canales biliares, la reparación biliar utilizando una parte de la vesícula biliar o un remanente del canal cístico y la repación biliar utilizando un parche de pared yeyunal. El periodo de observación postoperatoria osciló entre 8 meses y 7 años cuatro meses. Nuestra política es la de conservar la función de la papila de Vater cuando ésto sea posible, puesto que ello significa un flujo de bilis fissiológico. Nosotros recomendamos especialmente el uso de un parche yeyunal para la repación biliar, en casos en los cuales no exista un remanente utilizable de canal cístico. Este método es aplicable cuando la estrechéz biliar es de menos de 3 cm. Hemos operado dos pacientes con este método y los resultados han sido enteramente satisfactorios.


Surgery Today | 1978

Successfully resected carcinoma of the bifurcation of the main hepatic ducts--report of two cases.

Akira Nishimura; Masao Nakano; Koshi Maruyama; Takao Okamura; Takeshi Todoroki; Yoji Iwasaki

AbtractTwo cases of carcinoma of the bifurcation of the main hepatic ducts are presented. The tumors were successfully removed by resection of the bifurcation in one case, and by left hepatic lobectomy in the other. Some other 38 cases of the same condition collected from the world literature are briefly reviewed and discussed with particular reference to their surgical interventions.


Journal of pharmacobio-dynamics | 1986

Trimethadione tolerance test for evaluation of functional reserve of the liver in patients with liver cirrhosis and esophageal varices.

Einosuke Tanaka; Akio Ishikawa; Atsushi Ono; Takao Okamura; Shinichi Kobayashi; Hajime Yasuhara; Shogo Misawa


Journal of pharmacobio-dynamics | 1987

Trimethadione metabolism in patients with normal liver and in patients with chronic liver disease.

Einosuke Tanaka; Akio Ishikawa; Atsushi Ono; Takao Okamura; Shogo Misawa


Journal of pharmacobio-dynamics | 1986

HEPATIC TRIMETHADIONE-OXIDIZING CAPACITY REMAINS NORMAL IN PATIENTS WITH EXTRAHEPATIC CHOLELITHIASIS

Einosuke Tanaka; Akio Ishikawa; Atsushi Ono; Akira Takada; Takao Okamura; Shogo Misawa


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 1983

PREDICTABILITY OF RESPONSE TO SPLENECTOMY IN PATIENTS WITH IDIOPATHIC THROMBOCYTOPENIC PURPURA

Susumu Shibuya; Yasuhiro Takase; Katashi Fukao; Takao Okamura; Yoji Iwasaki; Toshiro Nagasawa; 阿部 帥


Japanese Journal of Thrombosis and Hemostasis | 1982

Estimation of soluble fibrin monomer complexes by high performance liquid chromatography

Akio Ishikawa; Katashi Fukao; Takao Okamura; Masafumi Komiya; Yoji Iwasaki

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Akira Nishimura

Kansai Medical University

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Masao Nakano

University of the Ryukyus

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