PubMed Health⌕ Search

Biomedical subjects

Takehide Asano

Publications and source records attributed to Takehide Asano.

At least 19 recordsLinked to original sources
PubMed2007

Relationship between right portal and biliary systems based on reclassification of the liver.

BACKGROUND: Although the anatomy of the right portal and biliary systems and their interrelationships must be understood to safely and satisfactorily perform left-sided resection of hilar cholangiocarcinoma or right-lobe living donor liver transplantation, the anatomies of the right portal and biliary systems are extremely difficult to understand. METHODS: A total of 60 patients with normal liver underwent computed tomography during both portography and cholangiography to evaluate relationships between the right biliary and portal systems based on reclassification of the liver to divide the right liver into 3 segments. RESULTS: All ventral and posterior ducts constantly join medially to the anterior portal trunk. In contrast, some dorsal ducts join the ventral duct medially and others join the posterior duct lateral to the anterior trunk. CONCLUSIONS: Reclassification of the liver to divide the right liver into 3 segments facilitates an understanding of relationships between the right portal and biliary systems.

Adolescent↗
PubMed2006

Aortic occlusion balloon catheter technique is useful for uncontrollable massive intraabdominal bleeding after hepato-pancreato-biliary surgery.

Massive intraabdominal hemorrhage sometimes requires urgent hemostatic surgical intervention. In such cases, its rapid stabilization is crucial to reestablish a general hemodynamic status. We used an aortic occlusion balloon catheter in patients with massive intraabdominal hemorrhage occurring after hepato-pancreato-biliary surgery. An 8-French balloon catheter was percutaneously inserted into the aorta from the femoral artery, and the balloon was placed just above the celiac artery. Fifteen minutes inflation and 5 minutes deflation were alternated during surgery until the bleeding was surgically controlled. An aortic occlusion balloon catheter was inserted on 13 occasions in 10 patients undergoing laparotomy for hemostasis of massive hemorrhage. The aorta was successfully occluded on 12 occasions in nine patients. Both systolic pressure and heart rate were normalized during aortic occlusion, and the operative field became clearly visible after adequate suction of leaked blood. Bleeding sites were then easily found and controlled. Hemorrhage was successfully controlled in 7 of 10 patients (70%), and they were discharged in good condition. The aortic occlusion balloon catheter technique was effective for easily controlling massive intraabdominal bleeding by hemostatic procedure after hepato-pancreato-biliary surgery.

Abdomen↗
PubMed2006

Preferable operative age of choledochal dilation types to prevent patients with pancreaticobiliary maljunction from developing biliary tract carcinogenesis.

BACKGROUND: Pancreaticobiliary maljunction (PBM), which frequently accompanies choledochal dilation, is a high risk factor for biliary tract (gallbladder, bile duct) carcinoma because of the continuous reflux of pancreatic juice into the biliary tract. The aim of this study was to clarify the preferable operative age in PBM patients for the prevention of biliary tract carcinogenesis, with reference to the dilation types of bile ducts. METHODS: There were 165 PBM patients in total studied, including 92 pediatric patients (< or =15 y) (cystic, 63; spindle-like, 29; nondilation, 0) and 73 adult patients (>15 y) (cystic, 45; spindle-like, 18; nondilation, 10) who underwent operative excision of extrahepatic bile ducts or cholecystectomy. We investigated incidence by age of biliary tract malignancies and the risk according to types of dilation. RESULTS: In the pediatric group, no carcinoma case could be found preoperatively or postoperatively (mean follow-up period, 11.7 y). In the adult group, bile duct carcinomas could be detected in 6 cases of a cystic type (6 of 45; 13.3%) (3 preoperative, 3 postoperative). Among the bile duct carcinoma cases, the youngest patient was a 21-year-old woman who had undergone excision of an extrahepatic bile duct 3 years previously. Gallbladder carcinomas were detected in 16 patients: 3 of 45 cystic (6.7%), 6 of 18 spindle-like (33.3%), and 8 of 10 nondilation (80.0%), in whom the youngest patient was a 41-year-old woman with a spindle-like type. CONCLUSIONS: To prevent biliary tract carcinogenesis in PBM patients, cystic-dilated choledochus should be excised in childhood before the development to a precancerous stage. In spindle-like and nondilation types, cholecystectomy is absolutely necessary in early adulthood before age 40.

Abnormalities, Multiple↗
PubMed2005

Oncolytic viral therapy for cervical and ovarian cancer cells by Sindbis virus AR339 strain.

PURPOSE: Recently, the application of replication-competent viruses has been studied as anticancer agents. Sindbis virus (SIN) is an RNA virus that belongs to the Alphavirus genus in the Togaviridae virus family. The AR339 strain of SIN has not been reported to induce any serious disease to humans. EXPERIMENTAL DESIGN: In this study, we evaluated the feasibility of the replication-competent SIN AR339 strain as an agent for cervical and ovarian cancer therapy. RESULTS: SIN infection was able to induce cytopathic effects and apoptosis in two cervical cancer cells (HeLaS3 and C33A) and three ovarian cancer cells (HOC-1, HAC-2, and OMC-3) but not in normal human keratinocytes in vitro. The analysis of cell viability, virus protein synthesis, and viral growth showed the cancer-specific cytotoxicity and virus growth of SIN. In nude mice, i.t. and i.v. inoculation of SIN resulted in significant regression of established cervical tumors implanted at their backs. Histologic studies revealed that systemic treatment with the single injection of SIN induces necrosis within tumors at a remote site. In the metastasis model of ovarian cancer, suppression of ascites formation was observed in nude mice with i.p. SIN treatment. By using an in vivo green fluorescent protein imaging system, we also showed that systemic treatment with SIN targeted tumors specifically. CONCLUSIONS: Our study suggested that SIN AR339 strain has a possibility as a novel agent for human cervical and ovarian cancer therapy.

Animals↗
PubMed2005

Hemodynamic changes of splenogastric circulation after spleen-preserving pancreatectomy with excision of splenic artery and vein.

BACKGROUND: The safety of spleen conservation without preservation of the splenic artery and vein was proved on the basis of short-term observation, but the long-term results of this procedure have been uncertain. To clarify the hemodynamic changes of splenogastric circulation of patients undergoing spleen-preserving pancreatectomy with excision of the splenic artery and vein, we retrospectively analyzed patient outcome with particular reference to the assessment of hemodynamic changes of splenogastric circulation. METHODS: Ten patients who had undergone spleen-preserving pancreatectomy with excision of the splenic artery and vein were retrospectively analyzed. In all patients both the short gastric and left gastroepiploic arteries and veins were preserved. All patients were observed for a minimum of 52 months. Collateral venous pathways were evaluated by computed tomography and endoscopy. RESULTS: Early complications such as splenic infarction and atrophy did not occur in any of the patients, but computed tomography revealed perigastric varices in 7 patients (70%) and submucosal varices in 2 patients (20%). Endoscopy showed gastric varices in 2 patients in whom submucosal gastric varices were identified on computed tomography. Gastrointestinal bleeding from gastric varices occurred in 1 patient. In 1 patient without gastric varices, a gastrorenal shunt was demonstrated on computed tomography. CONCLUSIONS: This study confirmed that gastric varices frequently occurred in patients who underwent spleen-preserving pancreatectomy with excision of the splenic artery and vein.

Esophageal and Gastric Varices↗
PubMed2004

Laparoscopic distal pancreatectomy as the total biopsy of the pancreas: tool of minimally invasive surgery.

Because of recent progress in imaging modalities, the opportunities to detect pancreatic cystic neoplasms are increasing. However, serous cystadenoma is still uncommon. We report a case of serous cystadenoma treated by laparoscopic distal pancreatectomy. A 52-year-old woman presented with mild upper abdominal pain. Dynamic computed tomography (CT) revealed a solitary cystic lesion 3 cm in diameter in the pancreatic tail. Endoscopic ultrasound showed a honeycomb pattern, indicative of serous cystadenoma. To obtain the final diagnosis of the tumor, we performed laparoscopic distal pancreatectomy. A histopathological study showed microcystadenoma with no evidence of malignancy.

Cystadenoma, Serous↗
PubMed2004

A randomized multicenter trial comparing resection and radiochemotherapy for resectable locally invasive pancreatic cancer.

BACKGROUND: Though the outcome of resection for locally invasive pancreatic cancer is still poor, it has gradually improved in Japan, and the 5-year survival is now about 10%. However, the advantage of resection over radiochemotherapy has not yet been confirmed by a randomized trial. We conducted this study to compare surgical resection alone versus radiochemotherapy without resection for locally invasive pancreatic cancer using a multicenter randomized design. METHODS: Patients with pancreatic cancer who met our preoperative criteria for inclusion (pancreatic cancer invading the pancreatic capsule without involvement of the superior mesenteric artery or the common hepatic artery, or without distant metastasis) underwent laparotomy. Patients with operative findings consistent with our criteria were randomized into a radical resection group and a radiochemotherapy group (200 mg/m(2)/day of intravenous 5-fluorouracil and 5040 cGy of radiotherapy) without resection. The 2 groups were compared for mean survival, hazard ratio, 1-year survival, quality of life scores, and hematologic and blood chemical data. RESULTS: Twenty patients were assigned to the resection group and 22 to the radiochemotherapy group. There was 1 operative death. The surgical resection group had better results than the radiochemotherapy group as measured by 1-year survival (62% vs 32 %, P=.05), mean survival time (>17 vs 11 months, P < .03), and hazard ratio (0.46, P=.04). There were no differences in the quality of life score or laboratory data apart from increased diarrhea after surgical resection. CONCLUSIONS: Locally invasive pancreatic cancer without distant metastases and major arterial invasion appears to be best treated by surgical resection.

Adult↗
PubMed2004

Effects of carbon-ion beams on human pancreatic cancer cell lines that differ in genetic status.

The relative biologic effectiveness (RBE) of carbon-ion beams at 3 different linear energy transfer (LET) values (13, 50, and 80 keV/microm) accelerated by the Heavy Ion Medical Accelerator in Chiba on human pancreatic cancer cell lines differing in genetic status was determined. The RBE values were calculated as D10, the dose (Gy) required to reduce the surviving fraction to 10%, relative to X-rays. We also investigated apoptosis and the relationship between D10 and the cell cycle checkpoint using morphologic examination and flow cytometry analysis, respectively. The RBE values calculated by the D10 values ranged from 1.16 to 1.77 for the 13-keV/microm beam and from 1.83 to 2.46 for the 80-keV/microm beam. A correlation between the D10 values of each cell line and intensity of G2/M arrest was observed. In contrast, LET values did not clearly correlate with induction of apoptosis. These results suggest that carbon-ion beam therapy is a promising modality. Elucidation of the mechanisms of G2/M arrest and apoptosis may provide clues to enhancing the effects of radiation on pancreatic cancer.

Apoptosis↗
PubMed2003

Effectiveness of hydroxyethyl starch (HES) on purification of pancreatic islets.

BACKGROUND: The isolation of large-scale and high-quality islets from the pancreas is essential for a successful islet transplantation. We developed a hydroxyethyl starch (HES)-Collins solution as the purification medium and evaluated its usefulness on islet isolation from the pancreas of beagle dogs. MATERIALS AND METHODS: The pancreas of beagle dog was digested using our original 2-step automated technique. Islets were purified by discontinuous purification method on HES-Collins solution (group 1, n = 10) or Euro-Ficoll solution (group 2, n = 16) with a COBE2991 cell processor. Islet yield and purity, changes in islet number during 3-day cultures, static incubation, perifusion study, and insulin content were examined. In addition, the islets were autotransplanted into the liver via the portal vein. RESULTS: Although no significant differences were detected, yield and purity were higher in group 1. After 3 days of culture, the islet number decreased less in group 1. Both under static incubation and in the perifusion study, stimulation indices were 4.50 +/- 1.82 and 6.02 +/- 1.05, which were significantly higher than the 2.18 +/- 0.67 and 3.32 +/- 1.46 observed in group 2. Also, insulin content of the islets was significantly higher in group 1 than in group 2. Fasting blood glucose levels were maintained at values below 100 mg/dl for 100 days in group 1 and around 200 mg/dl in group 2. CONCLUSIONS: The use of HES-Collins solution was associated with an improvement of islet yield and purity. Also, islet viability and function were preserved longer during culture. Accordingly, islet purification using HES-Collins solution might be recommended for clinical islet transplantation.

Animals↗
PubMed2003

Aggressive surgical resection for hilar-invasive and peripheral intrahepatic cholangiocarcinoma.

The clinicopathology and surgical outcome of intrahepatic cholangiocarcinomas are not fully understood. The objective of this study was to clarify the clinicopathologic features of intrahepatic cholangiocarcinoma and evaluate prognostic factors influencing survival. Forty consecutive patients with intrahepatic cholangiocarcinomas undergoing surgical resection at Chiba University Hospital between October 1981 and October 1997 were analyzed retrospectively. Intrahepatic cholangiocarcinomas were classified as hilar-invasive type ( n = 26) or peripheral type ( n = 14). Patients with peripheral-type tumors had a significantly ( p = 0.005) better 5-year survival rate (43%) than those with the hilar-invasive type (4%). Hilar-invasive-type tumors had perineural invasion (100%) and nodal involvement (85%) more frequently than did peripheral-type tumors. Despite aggressive surgical resection, the surgical margin was positive in 88% of patients with hilar-invasive type tumors (23/26) and 29% of patients with peripheral-type tumors (4/14). There was no evidence of a survival benefit of vascular resection for patients with a hilar-invasive intrahepatic cholangiocarcinoma. Patients with lymph node metastasis had a significantly worse prognosis ( p = 0.0004). No patients with nodal involvement survived more than 38 months. Negative perineural invasion ( p = 0.008) and a negative microscopic margin ( p = 0.008) were significantly associated with improved survival. Better survival results could be achieved by curative resection with a free margin for hilar-invasive and peripheral intrahepatic cholangiocarcinoma.

Bile Duct Neoplasms↗
PubMed2003

Successful treatment of lymph node metastases recurring from gallbladder cancer.

A 66-year-old woman who had undergone cholecystectomy for the treatment of gallbladder cancer 5 years and 10 months previously was referred to our center due to increased carbohydrate antigen (CA)19-9. Increased CA19-9 (136U/ml) was the only abnormality detected on initial examination, and, despite various tests, clear signs of recurrence could not be detected. Subsequently, the patient was followed. Six months after the initial examination, dynamic computerized tomography confirmed lymphadenopathy. The results of fluoro-deoxy-glucose positron emission tomography suggested lymph node metastasis of the gallbladder cancer, and after consideration of the site of recurrence and the length of time between the primary surgery and detection of recurrence, the patient underwent extrahepatic bile duct resection and lymphadenectomy. Levels of CA19-9 normalized postoperatively, and, at the time of writing (26 months postoperatively), blood tests and diagnostic imaging revealed no signs of recurrence.

Adenocarcinoma↗
PubMed2002

Long-term surgical outcome of noninvasive and minimally invasive intraductal papillary mucinous adenocarcinoma of the pancreas.

The objective of this study was to clarify the long-term outcome after surgical resection in patients with noninvasive and minimally invasive intraductal papillary mucinous adenocarcinoma. We performed a retrospective review of the clinicopathological features and outcome in patients who underwent pancreatic resection for noninvasive and minimally invasive intraductal papillary mucinous adenocarcinoma between November 1982 and December 1997 at Chiba University Hospital. Minimally invasive structures were pathologically observed in five cases. The mean age of patients with either noninvasive (n = 16) or minimally invasive n = 5) adenocarcinoma was 61 years. Of the patients with minimally invasive adenocarcinoma, 4 had abdominal pain. Conversely, 7 patients with noninvasive adenocarcinoma had no complaint. The mean size of noninvasive and minimally invasive tumors was 2.5 cm (range 0.8 to 4.0) and 3.3 cm (range 2.5 to 4.5), respectively. The overall 5-year and 10-year survival rates for all 21 patients were 89% and 47%, respectively. Disease recurred in 3 patients; 2 patients with minimally invasive adenocarcinoma and 1 with noninvasive adenocarcinoma. Recurrence sites were peritoneum = 2) and main pancreatic duct of the remnant pancreas (n = 1); 5 disease-free patients died of unrelated causes. The remaining 13 patients are alive and disease free 3 to 12 years after surgery. Noninvasive and minimally invasive intraductal papillary mucinous adenocarcinoma had a favorable prognosis after surgical treatment.

Adenocarcinoma, Mucinous↗
PubMed2002

Diagnosis and patient management of intraductal papillary-mucinous tumor of the pancreas by using peroral pancreatoscopy and intraductal ultrasonography.

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreas has attracted increasing interest because of its unique presentation. The differential diagnosis between malignant and benign tumors is extremely important in the determination of the therapy for IPMT. The aims of this study are to determine the usefulness of peroral pancreatoscopy (POPS) and intraductal ultrasonography (IDUS) in IPMT for the differentiation of malignant from benign disease, and to evaluate the significance of these techniques as new preoperative examinations. METHODS: Sixty histopathologically confirmed patients with IPMT underwent POPS and/or IDUS preoperatively. POPS was perfomed in all patients, and IDUS in 40. Findings of POPS and IDUS were compared with histopathology of resected specimens. The postoperative follow-up data were analyzed. RESULTS: Protruding lesions were detected by POPS in 40 patients. They were classified into 5 groups. Fish-egg-like type with vascular images, villous type, and vegetative type were considered to be malignant. By IDUS, lesions protruding 1 mm or more were observed in 36 patients. Of the lesions protruding 4 mm or more, 88% were malignant. Combination of POPS and IDUS improved the differential diagnosis between benign and malignant IPMT. The 3-year cumulative survival rate and disease-free survival rate were extremely high at 95% and 93%, respectively. CONCLUSIONS: The combination of POPS and IDUS results in a considerably improved differential diagnosis between malignant and benign IPMT and is useful for determining an effective therapeutic approach. These new techniques can contribute to improvements in postoperative results.

Adenoma↗
PubMed2002

Clinical application of (11)C-methionine positron emission tomography for evaluation of pancreatic function.

INTRODUCTION: In recent years, it has become increasingly necessary to evaluate pancreatic function after pancreatectomy, but few precise methods are available. AIMS: To evaluate different surgical techniques for pancreatectomy in terms of the preservation of pancreatic function by (11)C-methionine positron emission tomography (PET), which determines amino acid metabolism in the pancreas. METHODOLOGY: The study included 33 pancreatectomy cases: 5 of distal pancreatectomy, 5 of pancreaticoduodenectomy, 10 of pylorus-preserving pancreaticoduodenectomy, 7 of duodenum-preserving pancreatic head resection, and 6 of inferior pancreatic head resection. The method was as follows. Approximately 370 MBq (11)C-methionine was intravenously injected. Cross-sectional imaging of the pancreas was performed by PET after 30 minutes. The images obtained were used to determine the radioactivity concentration in the pancreas. By adjustment of the radioactivity concentration for body weight and dosage, the differential absorption ratio could be determined to indicate the level of accumulation in the pancreas. Each surgical method used was evaluated on the basis of the differential absorption ratio. Postoperative total pancreatic accumulation was divided by preoperative level to calculate the total preserved pancreatic function rate (TPPFR), and postoperative local pancreatic accumulation was divided by preoperative level to calculate the local preserved pancreatic function rate (LPPFR). These rates were then compared for the individual techniques used. RESULTS: The results indicated that TPPFR and LPPFR were 61.2 +/- 20.0% and 114.6 +/- 29.4% for distal pancreatectomy (n = 5), 31.8 +/- 20.0% and 58.7 +/- 30.0% for pancreaticoduodenectomy (n = 5), 21.6 +/- 14.7% and 58.4 +/- 29.8% for pylorus-preserving pancreaticoduodenectomy (n = 10), 47.9 +/- 35.5% and 67.7 +/- 30.6% for duodenum-preserving pancreatic head resection (n = 7), and 48.1 +/- 29.5% and 83.9 +/- 30.5% for inferior pancreatic head resection (n = 6). TPPFR was highest in distal pancreatectomy cases. Among the pancreatic head resections, TPPFR was quite high for both inferior pancreatic head resection and duodenum-preserving pancreatic head resection. In contrast, TPPFR for pancreaticoduodenectomy and pylorus-preserving pancreaticoduodenectomy was quite low. LPPFR was highest for distal pancreatectomy and only slightly lower for inferior pancreatic head resection. In contrast, LPPFR was markedly lower for pancreaticoduodenectomy and pylorus-preserving pancreaticoduodenectomy. CONCLUSION: In conclusion, this method using (11)C-methionine PET is clearly useful for the evaluation of pancreatic function after pancreatectomy.

Aged↗
PubMed2002

Posthepatectomy hepatitis shortens tumor-free intervals in hepatitis C virus-associated hepatocellular carcinoma patients.

In hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC), serum alanine aminotransferase (ALT) is frequently sustained on a high level after hepatectomy, with the formation of recurrent HCC tumors during follow-up periods. We investigated whether or not postoperative serum ALT level affects the interval before recurrence in hepatitis C virus-associated HCC. The subjects studied were 50 hepatectomized HCC patients who were HCV-Ab(+), and underwent a curable surgery in our Hospital from June 1990 to December 1999. We assessed the significance of the postoperative serum ALT level affecting tumor-free survival rates, as compared with other clinicopathological parameters, using univariate and multivariate Cox proportional hazard analysis. Thereafter, tumor-free and overall survival rates after hepatectomy were compared between high and low ALT groups, using Kaplan-Meier plotting and a log-rank test. The factor of ALT levels (a high or low ALT group) was most strongly associated with a tumor-free survival rate. Both tumor-free and overall survival rates were significantly poorer in the high ALT group than in the low ALT group among HCV-associated HCC cases (p<0.05). The results in this study suggest that postoperative hepatitis, which is indicated by sustained high ALT levels, may shorten the interval before recurrence in HCV-associated HCC. We should take care to control postoperative hepatitis to improve the prognoses of HCV-associated HCC cases.

Alanine Transaminase↗