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Biomedical subjects

A Harada

Publications and source records attributed to A Harada.

356 records · Page 20Linked to original sources
PubMedDate not supplied

Intraoperative diagnosis of pancreatic cancer extension using IVUS.

BACKGROUND/AIMS: Pancreatic cancer easily invades retroperitoneal tissue, especially the portal vein and extrapancreatic nerve plexus. We evaluated the diagnostic accuracy of intraportal endovascular ultrasonography in portal vein and extrapancreatic nerve plexus invasion. METHODOLOGY: Intraportal endovascular ultrasonography was performed in 78 cases of pancreatic cancer (head 67, body 8, total 3). Intraportal endovascular ultrasonography was performed intraoperatively from the superior mesenteric vein with an 8-French, 20-MHz intravascular ultrasound catheter. Three-dimensional intraportal endovascular ultrasonography was constructed by volume rendering. RESULTS: Intraportal endovascular ultrasonography visualized the portal vein as an echogenic band with a thickness of 0.5 mm to 1.0 mm. The diagnostic criterion of portal vein invasion was obliteration of this echogenic band. Intraportal endovascular ultrasonography visualized segment II of the extrapancreatic nerve plexus as the high-echoic area around the inferior pancreaticoduodenal artery. The diagnostic criterion of extrapancreatic nerve plexus invasion was low-echoic infiltration around the inferior pancreaticoduodenal artery. The sensitivity, specificity, and overall accuracy of intraportal endovascular ultrasonography for diagnosis of portal vein invasion was, respectively, 97.4%, 92.5%, and 94.9%. The values for diagnosis of extrapancreatic nerve plexus invasion, respectively, were 94.4%, 97.1%, and 96.2%. Three-dimensional intraportal endovascular ultrasonography depicted the invasion area as a defect of the portal vein wall. CONCLUSIONS: Intraportal endovascular ultrasonography detected subtle portal invasion and provided accurate portal invasion area which was useful for portal vein an reconstruction. Intraportal endovascular ultrasonography could also diagnose the extrapancreatic nerve plexus invasion of segment II.

Aged↗
PubMedDate not supplied

The role of extended radical operation for pancreatic cancer.

BACKGROUND/AIMS: To clarify the indication of extended operation for pancreatic carcinoma, a clinical study was carried out. METHODOLOGY: From July 1981 to 1999, 196 of 307 (63.8%) patients with pancreatic carcinoma underwent resection of the tumor. Portal vein resection was performed in 145 of these 196 (74.0%) resected cases. The postoperative survival rate was studied according to the operative and histopathological findings. RESULTS: In spite of the aggressive surgery, there was no patient who survived over 3 years after operation in the group carcinoma-positive on the surgical margins. Patients who survived over 3 years postoperatively were observed in the group of carcinoma-free surgical margins. CONCLUSIONS: The most important indication of extended operation combined with portal vein resection for pancreatic cancer is to obtain surgical cancer-free margins. There is no indication of extended operation for cases in which surgical margins will become cancer-positive, if such an operation is employed.

Constriction, Pathologic↗
PubMedDate not supplied

The role of adjuvant therapy for pancreatic cancer.

BACKGROUND/AIMS: In spite of radical pancreatectomy with lymphadenectomy for adenocarcinoma of the pancreas, survival remains poor. We add two forms of adjuvant therapy, i.e., intraoperative radiotherapy and liver perfusion chemotherapy, to the radical resection. The aim of this study is to investigate the utility of these two forms of adjuvant therapy prospectively and to review their effectiveness. METHODOLOGY: One hundred and ninety-six patients with pancreatic cancer who underwent radical pancreatectomy in our institute were enrolled. We conducted intraoperative radiation therapy 30 Gy against the retroperitoneal connective tissues around the superior mesenteric artery during surgery. Adjuvant liver perfusion chemotherapy was added immediately after operation via the portal vein using 5-fluorouracil (250 mg/body/day) for 3 to 4 weeks continuously. Overall survival analyses were done by the method of Kaplan and Meier. RESULTS: Intraoperative radiation therapy did not influence the prognoses directly. However, the patients who received adjuvant liver perfusion chemotherapy had better prognoses (P < 0.05). CONCLUSIONS: Although adjuvant therapy after radical resection with wide lymphadenectomy improves prognoses, the results are still not satisfactory. We should develop a new and more efficacious treatment.

Adenocarcinoma↗
PubMedDate not supplied

Gene therapy for pancreatic cancer.

Despite improvements in surgical care and locoregional therapy, the prognosis of patients with pancreatic cancer has seen little improvement over the last several decades. It is difficult to diagnose pancreatic cancer at its earliest stages when it is amenable to cure by surgical resection because it is too small to produce symptoms in the affected patient. Recent improvements in radiographic modalities aimed at earlier detection and extent of cancer spread have enabled the clinician to provide the most efficacious treatment regimen possible. Nevertheless, pancreatic cancer is very aggressive locally and frequently metastasizes to the liver and peritoneum. New strategies are necessary to treat pancreatic cancer and gene therapy offers hope in this regard. Many studies have revealed the promise of gene therapy in the treatment of pancreatic cancer in rodent models. Early clinical trials are ongoing to evaluate the success of these gene therapy regimens in humans. In this article we review the gene therapy strategies currently employed in the fight against pancreatic cancer, including antisense strategies, gene-directed prodrug activation therapy, promoter gene strategies, and oncolytic viral therapy.

Animals↗
PubMedDate not supplied

Surgical treatment of intraductal papillary-mucinous tumors of the pancreas.

BACKGROUND/AIMS: IPMT (Intraductal papillary-mucinous tumor of the pancreas) is increasingly recognized. The aim of this study was to investigate the appropriate surgical treatment for these tumors. METHODOLOGY: Between January 1981 and September 1998, 62 patients with IPMT underwent surgery. We retrospectively examined the clinicopathological features and surgical outcomes of the patients. RESULTS: The types of IPMT were as follows: hyperplasia (20); adenoma (31); and carcinoma, both invasive (5) and noninvasive (6). Lymph node metastasis was found in 36% of the carcinomas. The size of mural nodules was more than 3 mm in all adenoma or carcinoma cases, while the percentage of hyperplasia less than 3 mm was 75%. Intraoperative pancreatoscopy and annular array ultrasonography were very useful, because they detected 10 lesions that could not be found by preoperative examinations, such as computed tomography, endoscopic retrograde pancreatography, and endoscopic ultrasonography. All patients underwent surgical resection, including 10 pancreaticoduodenectomies (Whipple's procedure), 10 pylorus-preserving pancreaticoduodenectomies, 13 pancreatic head resections with segmental duodenectomies, 17 distal pancreatectomies, 9 segmental resections of the pancreas, 2 duodenum-preserving pancreatic head resections, and 1 total pancreatectomy. No operative or hospital death was observed. The postoperative survival rate at 5 years was 71.6% for carcinoma in IPMT. All of the cases with hyperplasia, adenoma and noninvasive carcinoma survived. Only two of the patients with invasive carcinoma died. CONCLUSIONS: IPMT had a favorable prognosis, as compared with pancreatic duct carcinoma. When selecting a surgical procedure for treating these tumors, it is important to confirm the tumor extent, as well as the diagnosis of invasion or noninvasion. In cases with invasion, radical resection is required. On the other hand, organ-function-preserving procedures should be selected for diseases without invasion.

Adult↗
PubMedDate not supplied

Nodular regenerative hyperplasia of the liver with and without portal hypertension: a comparison.

The clinical and the pathologic features of seven patients with nodular regenerative hyperplasia of the liver are analyzed and compared with those of 37 patients reported in the literature in an attempt to distinguish the features of those with portal hypertension from those without. Severe degrees of obliterative portal venopathy usually associated with the portal hypertension were found among the various pathological features. The association of nodular regenerative hyperplasia with a variety of chronic diseases suggests a heterogeneous group of pathogenic mechanisms. Our study reveals that only some of these mechanisms lead to the hepatic changes that cause portal hypertension.

Adult↗
PubMedDate not supplied

Immunohistochemical detection of endotoxin in endotoxemic rats.

BACKGROUND/AIMS: Although there are various methods to detect endotoxin mainly after the intravenous injection of purified endotoxin in a host, its uptake and distribution among the various organs is not well understood. In the present study, the time course of the distribution and disappearance of endotoxin in various rat organs following injection via two different routes was evaluated by an immunohistochemical staining method using a newly developed monoclonal antibody against Factor C. MATERIALS AND METHODS: The time course of the distribution of lipopolysaccharide (LPS) into the liver, spleen, lung, and kidney after intravenous (i.v.) or intraperitoneal (i.p.) injection of LPS was studied by immunohistochemical staining using a newly developed monoclonal antibody against Factor C in rats. Moreover, plasma endotoxin levels were measured by a modification of a chromogenic endotoxin-specific assay. RESULTS: At 30 minutes after injection in the i.v. group and at 12 and 24 hours in the i.p. group, endotoxin was present on Kupffer cells by staining and on some sinusoidal endothelial cells in the liver as well as on macrophages in the marginal zone of the spleen. The plasma endotoxin levels in the i.v. group decreased gradually after injection. However, levels in the i.p. group gradually increased, reaching a maximum level at 6 hours after injection, and then gradually decreasing. CONCLUSION: These results suggest that, regardless of the route of injection, endotoxin can be detected by an immunohistochemical staining method using a monoclonal antibody against Factor C.

Animals↗
PubMedDate not supplied

Intraportal endovascular ultrasonography as a new diagnostic procedure in pancreatic surgery.

BACKGROUND/AIMS: This presents the results of a prospective study on the use of intraportal endovascular ultrasonography (IPEUS) as a screening tool for pancreatic carcinoma. PATIENTS AND METHODS: Twenty-four patients with pancreatic cancer (17 head, 7 body) were studied for portal vein invasion using intraportal endovascular ultrasonography (IPEUS). In 22 cases, IPEUS was performed intraoperatively from the superior mesenteric venous route with an 8-French, 20 MHz intravascular ultrasound (IVUS) catheter, in two cases preoperatively from the percutaneous transhepatic route with a 6- French, 20 MHz IVUS catheter. The sonographic criterion for detection of portal venous invasion was obliteration of the echogenic band of the portal vein. The IPEUS results were compared with those of CT and portography. RESULTS: Vascular invasion was confirmed with resected specimens in nine cases and with operative findings in three patients. For diagnosis of portal venous invasion, the sensitivity, specificity, and overall accuracy of IPEUS were 100%, 91.7%, and 95.8% respectively. For portography, the equivalent values were 66.7%, 75%, and 70.8%, while those for CT were 75%, 66.7%, and 70.8%.

Aged↗
PubMedDate not supplied

Regional vascular resection using catheter bypass procedure for pancreatic cancer.

BACKGROUND/AIMS: To elucidate the indications for extended operation including main vessel resection in pancreatic cancer surgery, a clinical study was performed. The safety and clinical significance of portal vein resection in pancreatic cancer surgery have not yet been obtained in a large series. MATERIALS AND METHODS: Over a period of more than 10 years, 134 of 212 (63%) patients with pancreatic carcinoma underwent resection by extensive radical surgery. Portal vein resection was performed in 104 of 134 (78%) resected cases using catheter bypass procedure. The postoperative survival was investigated and a clinicopathological study was conducted. RESULTS: Operative death within 30 days after operation was observed in 11 of 134 (8%) resected cases. Postoperative survival rate correlated with the grade of portal vein invasion, which was diagnosed by preoperative or intraoperative portography. Survival for more than two years after operation was seen in cases of negative invasion on the margins of the resected specimens group even when portal system vein wall invasion was observed. CONCLUSION: Portal vein resection is performed safely using bypass procedure of the portal vein and is recommended to obtain a tumor-free surgical margin.

Catheterization, Peripheral↗
PubMedDate not supplied

Expression of sialyl Lewis(x) in hepatocellular carcinoma.

BACKGROUND/AIMS: Expression of the sialyl Lewis(x) antigen, a cell adhesion molecule, was studied immunohistochemically in patients with hepatocellular carcinomas. MATERIALS AND METHODS: Fifty-six patients who underwent curative hepatic resections from July 1984 to October 1990 were studied. RESULTS: Hepatocellular staining patterns of the sialyl Lewis(x) in cancerous or noncancerous regions were divided into the three categories of high grade (HG), medium grade (MG), and low grade (LG). In cancerous regions, HG:54% (30/56); MG:13% (7/56); LG:34% (19/56). In noncancerous regions, HG: 86% (48/56), MG:4% (2/56), LG:11% (6/56). Patients with LG or MG sialyl Lewis(x) expression in cancerous regions had vascular invasion more frequently, and larger maximum diameters than HG patients, both with statistical significance (p<0.01, p<0.05, respectively). The 20 cases in which the expression of sialyl Lewis(x) in cancerous regions was downgraded compared with noncancerous regions (from HG in noncancerous regions to MG or LG in cancerous regions; from MG in noncancerous regions to LG in cancerous regions), also had vascular invasion significantly more frequently than the other 36 cases (p<0.02). CONCLUSION: These results lead us to speculate that the diminishing change of hepatocellular sialyl Lewis(x) expression with malignant transformation, or the small amounts of hepatocellular sialyl Lewis(x) expression in cancerous regions, are related to tumor spread of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
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Hepatic resection for hepatocellular carcinoma with a tumor thrombus extending to inferior vena cava.

The significance of hepatic resection for hepatocellular carcinoma with a tumor thrombus in the inferior vena cava (IVC) is clarified. We operated on 4 patients with HCC who had a tumor thrombus extending to the IVC through the hepatic vein under hepatic vascular exclusion (HVE). In all patients the hepatic resections and thrombectomies were successful without major complication. One patient accompanied with a tumor thrombus in the portal vein had a rash recurrence in the remnant liver and died 6 months after operation. However, three patients without tumor thrombus in the portal vein survived relatively longer post-operatively. Hepatic resection for HCC with tumor thrombus in IVC is acceptable treatment as it is safe. It is considered that better prognoses can be maintained when a tumor thrombus is located only in the hepatic vein, and not in the portal vein.

Aged↗
PubMedDate not supplied

Intraoperative radiotherapy for pancreatic carcinoma with hepatic or peritoneal metastases.

BACKGROUND/AIMS: The purpose of this study was to determine the efficacy of intraoperative radiotherapy (IORT) for unresectable pancreatic carcinoma associated with hepatic or peritoneal metastasis. METHODOLOGY: Between 1991 and 1994, 53 patients with pancreatic carcinoma associated with hepatic or peritoneal metastasis underwent surgery. Twenty-four of these patients received IORT, while 29 received no radiation therapy. The efficacy of IORT on the postoperative survival and pain relief for these patients was retrospectively analyzed. RESULTS: Postoperative survival was lowest in the subgroup of patients (n = 18) with both hepatic and peritoneal metastases, and this group did not benefit from IORT (IORT, n = 6; no IORT, n = 12) in terms of survival. Similarly, there was no significant difference in the survival rates between patients undergoing IORT (n = 10) and patients without IORT (n = 11) in the subgroup of patients with hepatic metastasis but without peritoneal metastasis. However, patients with peritoneal metastasis but without hepatic metastasis benefited significantly from IORT (IORT, n = 8; no IORT, n = 6) (p < 0.05). Pain relief following IORT was observed in 9 out of 10 patients who had experienced pain prior to surgery. CONCLUSION: Pancreatic carcinoma associated with peritoneal metastasis but without hepatic metastasis can be palliated by IORT. In addition, pain palliation in patients who require gastrointestinal or biliary drainage can also be achieved by IORT.

Humans↗