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Dive into the research topics where Masafumi Yasunaga is active.

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Featured researches published by Masafumi Yasunaga.


Surgery Today | 1999

Functional results of colonic J-pouch anastomosis for rectal cancer.

Yasumi Araki; Hiroharu Isomoto; Yoshiaki Tsuzi; Atsushi Matsumoto; Masafumi Yasunaga; Kenzi Yamauchi; Katsumi Hayashi; Takahito Kodama

The purpose of this study was to clarify the functional outcomes of colonic J-pouch anastomosis (J-LAR) for lower rectal cancer in comparison with those of traditional straight anastomosis (S-LAR). A questionnaire regarding anorectal function was conducted 1 year after operation on patients who underwent J-LAR (n=15) and S-LAR (n=30). The clinical functions were assessed by an incontinence scoring system. The physiologic function was assessed by anorectal manometry and the balloon expulsion test. No patients demonstrated a diverting stoma. The bowel frequency (range) 1 year after operation was 4.8 (3–6) in the S-LAR group and significantly decreased to 1.8 (1–3) in the J-LAR group (P<0.05). Complete evacuation was 50.2% (40%–60%) in the S-LAR group and significantly increased to 80.6% (60%–90%) in the J-LAR group (P<0.05). Neorectal compliance was 2.2 (1.4–2.9) ml/mmHg in the S-LAR group and significantly increased to 3.1 (1.3–3.5) ml/mmHg in the J-LAR group (P<0.01). No significant difference was observed between the two groups regarding the maximum resting or maximum voluntary squeezing pressure. In conclusion, our findings suggested colonic pouch anastomosis performed after a low anterior resection to support the compliance of the (neo)rectum to be an important factor for retaining a satisfactory bowel frequency.


Journal of Hepato-biliary-pancreatic Sciences | 2013

Gallbladder bed resection or hepatectomy of segments 4a and 5 for pT2 gallbladder carcinoma: analysis of Japanese registration cases by the study group for biliary surgery of the Japanese Society of Hepato-Biliary-Pancreatic Surgery

Akihiko Horiguchi; Shuichi Miyakawa; Shin Ishihara; Masaru Miyazaki; Masayuki Ohtsuka; Hiroaki Shimizu; Keiji Sano; Fumihiko Miura; Tetsuo Ohta; Masato Kayahara; Masato Nagino; Tsuyoshi Igami; Satoshi Hirano; Hiroki Yamaue; Masaji Tani; Masakazu Yamamoto; Takehiro Ota; Mitsuo Shimada; Yuji Morine; Hisafumi Kinoshita; Masafumi Yasunaga; Tadahiro Takada

PurposeHepatectomy of segments 4a and 5 (S4a+5) is the recommended treatment for pT2 gallbladder cancer. However, gallbladder bed resection is also occasionally used. Using nationwide data from the Japanese Biliary Tract Cancer Registry and a questionnaire survey, we retrospectively compared these 2 methods of treatment.MethodThe study involved 85 patients with pT2, pN0 gallbladder cancer (55 treated with gallbladder bed resection, and 30, with S4a+5 hepatectomy). The prognosis and mode of tumor recurrence following treatment were analyzed retrospectively, with overall survival as the endpoint.ResultsThe 5-year survival rate did not differ significantly between the 2 groups. Univariate analysis showed that bile duct resection and perineural tumor invasion were significant prognostic factors, but the extent of hepatectomy, location of the major intramural tumor, regional lymph node excision, and histological type were not. Multivariate analysis identified perineural tumor invasion as a significant prognostic factor. Recurrence occurred most frequently in both lobes than S4a+5 of the liver following gallbladder bed resection.ConclusionIn the present study of cases of Japanese Biliary Tract Cancer Registry, it was not possible to conclude that S4a+5 hepatectomy was superior to gallbladder bed resection.


Transplant International | 2005

Reliability of hepatic artery configuration in 3D CT angiography compared with conventional angiography – special reference to living-related liver transplant donors

Hisamune Sakai; Koji Okuda; Masafumi Yasunaga; Hisafumi Kinoshita; Shigeaki Aoyagi

Although an accurate anatomical understanding of the hepatic arteries is the most and essential step in living‐related liver transplantation (LRLT), the need to reduce the burden place on the donor should be considered in imaging diagnosis. The present study examined the reliability of intravenously enhanced three‐dimensional (3D) angiography from multidetector‐row computed tomography (MDCT) in evaluating the anatomical configuration of the hepatic arteries comparing with those from conventional angiography by Seldinger method. A total of 109 patients underwent MDCT and 3D images were reconstructed on arterial phase using the volume rendering (VR) method. In the case of 3D angiography, at an infusion rate of 4 ml/s, the extrahepatic hepatic arteries were visualized successfully in all cases (the right, left and middle hepatic artery). The aberrant hepatic arteries were successfully visualized in 23 of 24 cases. The 3D angiography is a reliable method of visualizing the extrahepatic and aberrant hepatic arteries. This minimally invasive examination procedure is useful in individual operative planning and is help to increase the safety of surgery.


Journal of the Pancreas | 2012

Metastatic Pulmonary Adenocarcinoma 13 Years After Curative Resection for Pancreatic Cancer: Report of a Case and Review of Japanese Literature

Yuhei Kitasato; Masamichi Nakayama; Gen Akasu; Munehiro Yoshitomi; Kazuhiro Mikagi; Yuichiro Maruyama; Ryuichi Kawahara; Hiroto Ishikawa; Toru Hisaka; Masafumi Yasunaga; Hiroyuki Horiuchi; Naoyuki Saito; Shinzo Takamori; Yoshinobu Okabe; Masayoshi Kage; Hisafumi Kinoshita; Hiroyuki Tanaka

CONTEXT For the majority of patients, ductal adenocarcinoma of the pancreas remains a lethal disease. Currently, surgical extirpation for localized disease offers the only chance for long-term survival. CASE REPORT We report a patient who underwent successful resection of isolated lung metastasis occurring 13 years after pancreatic cancer resection. A 59-year-old woman underwent distal pancreatectomy for pancreatic cancer 13 years previously, followed by adjuvant chemotherapy, and was followed-up at the outpatient clinic of a local hospital. From around June 2010, she noticed bloody sputum, so she visited a local hospital. Since her chest X-ray and CT revealed a 1.5 cm mass shadow in the segment 10 of her right lung and she was referred to the Respiratory Disease Center of our hospital. As a result of through examinations, she was strongly suspected of having lung metastasis of pancreatic cancer, and underwent partial pneumonectomy. Postoperative histopathological examination of the resected specimen was consistent with lung metastasis of pancreatic cancer. She is still alive and currently receives third line of chemotherapy. CONCLUSION Patients who have achieved long-term survival after pancreatic cancer resection and can tolerate surgery may benefit from resection of a lung metastasis of pancreatic cancer in terms of survival, if it controls the metastasis.


Surgery Today | 1999

Transsacral rectopexy for recurrent complete rectal prolapse.

Yasumi Araki; Hiroharu Isomoto; Yoshiaki Tsuzi; Atsushi Matsumoto; Masafumi Yasunaga; Kenzi Yamauchi; Katsumi Hayashi; Takahito Kodama

The aim of this study was to examine the functional outcome of transsacral rectopexy performed with Dexon mesh for recurrent complete rectal prolapse. Anorectal function was assessed by anorectal manometry and defecography, before and from 1 year after surgery in five patients who were followed up for 1–3 years. The fecal incontinence score recovered from a preoperative mean score of 3.8 to a postoperative mean score of 1.2, and constipation was improved in four patients (80%). The straining anorectal angle (S-ARA), measured by defecography, improved from a preoperative value of 120.6°±6.9° to a postoperative value of 98.5°±3.5° (P<0.05), and the perineal descent (PD) improved from a preoperative value of 16.2±2.5 cm to a postoperative value of 8.1±1.3 cm (P<0.05). The maximal resting pressure (MRP) increased from a preoperative value of 20.5±3.7 cmH2O to a postoperative value of 40.5±4.8 cmH2O (P<0.05). These findings indicate that transsacral rectopexy with Dexon mesh can achieve good control of recurrent complete rectal prolapse.


Journal of Hepato-biliary-pancreatic Surgery | 1995

Hilar bile duct resection for bile duct carcinoma at the hilus of the liver

Toshimichi Nakayama; Hideki Saitsu; Jyunji Shibata; Akira Hasuda; Hisafumi Kinoshita; Masafumi Yasunaga

Hilar bile duct resection, by which only the bile duct is resected, was carried out in 31 patients with bile duct carcinoma at the hepatic hilus. However, curative resection was possible in only 4 patients (12.9%). The postoperative 1-, 3-, and 5-year survival rates were 58.1%, 19.4%, and 7.7%, respectively. These results indicate that treatment of this hilar bile duct carcinoma by hilar bile duct resection is of limited value. We believe that this operative procedure should be used only for papillary or nodular carcinoma at the hepatic confluence at relatively early stages of Bismuths type I or II.


Surgery Today | 2009

Spontaneous rupture of the spleen caused by a Bacillus infection: Report of a case

Shigeaki Aoyagi; Tomokazu Kosuga; Toshiro Ogata; Masafumi Yasunaga

We report a case of spontaneous splenic rupture (SSR) caused by a Bacillus species (sp.) infection. A 36-year-old man on warfarin therapy since an aortic valve replacement at the age of 13 was admitted to our hospital with a 3-week history of a high fever. He had been asymptomatic until 4 months previously, when he suffered a cerebral embolism despite adequate oral anticoagulation. Abdominal computed tomography revealed splenic infarctions, which resulted in splenic rupture 2 days later. After embolization of the splenic artery, splenectomy was successfully performed. Pathologic examination revealed splenic infarction, resulting from septic emboli, with associated rupture of the splenic capsule, but no abscess was found. Bacillus sp. was isolated from cultures of arterial blood preoperatively, and the excised splenic specimens, postoperatively. In addition to rupture of the suppurating intrasplenic vessels with hematoma formation, the anticoagulant therapy possibly contributed to distension of the intrasplenic hematoma.


European Journal of Radiology | 2016

The correlation between FDG uptake and biological molecular markers in pancreatic cancer patients.

Hayato Kaida; Koichi Azuma; Akihiko Kawahara; Masafumi Yasunaga; Yuhei Kitasato; Satoshi Hattori; Tomoki Taira; Hiroki Ureshino; Masayoshi Kage; Kazunari Ishii; Takamichi Murakami; Masatoshi Ishibashi

PURPOSE We examined whether fluorine-18 fluorodeoxyglucose (FDG) uptake is related to the mammalian target of rapamycin (mTOR) signal pathway and its related proteins in pancreatic cancer patients. METHODS We retrospectively studied 53 pancreatic cancer patients who underwent FDG positron emission tomography (PET) or FDG PET/CT, and complete curative surgical resection. The SUV max, the tumor to nontumor activity of pancreas [T/N (P)] ratio and the T/N of liver [T/N (L)] ratio were calculated. The expressions of glucose transporter-1(Glut-1) and mTOR pathway proteins in pancreas cell lines were examined by immune blots. Excised tumor tissue was analyzed by immunohistochemistry using monoclonal antibodies for Glut-1, epidermal growth factor receptor (EGFR), mTOR, p70S6kinase (p70S6) and S6 ribosomal protein (S6). RESULTS The expressions of Glut-1, EGFR and p70S6 were significantly correlated with the SUV max, T/N (P) ratio and T/N (L) ratio. The expressions of mTOR and S6 were not correlated with all parameters. The expression of Glut-1 was positively correlated with the expressions of EGFR and p70S6, but not with mTOR or S6. S6 was positively correlated with p70S6. CONCLUSIONS Glut-1, EGFR and p70S6 expressions are associated with the FDG uptake mechanism of pancreatic cancer. FDG uptake may predict the levels of EGFR and p70S6 expressions, and FDG uptake reflects glucose metabolism and cancer progression.


Diseases of The Colon & Rectum | 2000

Continuous intra-arterial 5-FU chemotherapy in a patient with a repeated recurrence of rectal cancer report of a case

Uhi Toh; Hiroharu Isomoto; Yasumi Araki; Atsushi Matsumoto; Masafumi Yasunaga; Yoshio Ogoh; Kiyohisa Inuzuka; Kunihiro Ozaki

PURPOSE: We report a patient with a recurrent pelvic tumor after abdominoperineal resection of a rectal carcinoma who was treated sufficiently by repeated intra-arterial infusions of 5-fluorouracil. METHODS: A continuous, 24-hour 5-fluorouracil administration was made through the bilateral internal iliac artery at a dosage of 250 mg/m2/day by the subcutaneous reservoir located at both upper legs using a Baxter infusor. RESULTS: In this patient pain in the hip and pelvis was relieved. A complete regression in the infused field of pelvic tumor was observed not only with computed tomography and magnetic resonance imaging but also confirmed by operative findings at the seventh month after the intra-arterial infusion. The abnormal serum level of carcinoembryonic antigen and carbohydrate antigen 19-9 was decreased to within the normal range at the 19th and 3rd week respectively. When the repeated recurrence was supected in follow-up, normalization of the re-elevated carcinoembryonic antigen and carbohydrate antigen 19-9 levels was also obtained by repeating the same treatment. The side effects and complications were tolerable, consisting of local skin erosion on the hips and lower extremity neuropathy caused by the 5-fluorouracil. CONCLUSIONS: Clinical local regression of a pelvic recurrence was observed in a patient with rectal recurrent tumor who received continuous intra-arterial chemotherapy. Local recurrence of rectal cancer may be controlled effectively and safely by repeating long-term, continuous, intra-arterial 5-fluorouracil infusion.


Molecular Cancer | 2016

ARHGEF15 overexpression worsens the prognosis in patients with pancreatic ductal adenocarcinoma through enhancing the motility and proliferative activity of the cancer cells

Hiroto Fukushima; Makiko Yasumoto; Sachiko Ogasawara; Jun Akiba; Yuhei Kitasato; Masamichi Nakayama; Yoshiki Naito; Yusuke Ishida; Yoshinobu Okabe; Masafumi Yasunaga; Hiroyuki Horiuchi; Etsuko Sakamoto; Hiraku Itadani; Shinji Oie; Hirohisa Yano

BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplastic diseases, associated with a remarkably poor prognosis. However, the molecular mechanisms underlying the development of PDAC remain elusive. The aim of this study was to identify genes whose expressions are correlated with a poor prognosis in PDAC patients, and to unravel the mechanisms underlying the involvement of these genes in the development of the cancer.MethodsGlobal gene expression profiling was conducted in 39 specimens obtained from Japanese patients with PDAC to identify genes whose expressions were correlated with a shorter overall survival. The effect of gene silencing or overexpression of ARHGEF15 in pancreatic cancer cell lines was examined by introducing siRNAs of ARHGEF15 or the ARHGEF15 expression vector. After assessing the effect of ARHGEF15 deregulation on the Rho-family proteins by pull-down assay, wound healing, transwell and cell viability assays were carried out to investigate the cellular phenotypes caused by the perturbation.ResultsThe global mRNA expression profiling revealed that overexpression of ARHGEF15, a Rho-specific GEF, was significantly associated with a poor prognosis in patients with PDAC. We also found that the depletion of ARHGEF15 by RNA interference in pancreatic cancer cell lines downregulated the activities of molecules of the Rho signaling pathway, including RhoA, Cdc42 and Rac1. Then, we also showed that ARHGEF15 silencing significantly reduced the motility and viability of the cells, while its overexpression resulted in the development of the opposite phenotype in multiple pancreatic cancer cell lines.ConclusionThese data suggest that upregulation of ARHGEF15 contributes to the development of aggressive PDAC by increasing the growth and motility of the pancreatic cancer cells, thereby worsening the prognosis of these patients. Therefore, ARHGEF15 could serve as a novel therapeutic target in patients with PDAC.

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