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Biomedical subjects

Y Kamiyama

Publications and source records attributed to Y Kamiyama.

At least 19 recordsLinked to original sources
PubMed2003

Prevention of pleural effusion following hepatectomy using argon beam coagulation.

BACKGROUND: Postoperative pleural effusion occurs frequently after hepatectomy. The value of the argon beam coagulator (ABC) for the prevention of pleural effusion after hepatectomy in patients with hepatocellular carcinoma was studied. METHODS: Sixty patients were divided randomly into two groups: an ABC group (n = 28), in which the cut surface of the hepatic ligaments and bare area of the retroperitoneum were cauterized using an ABC, and a control group (n = 32) in which the ABC was not applied. Patient characteristics, preoperative and postoperative liver function, and postoperative pleural effusion were compared between the two groups. RESULTS: There were no significant differences between the two groups with respect to histological findings, clinical stage, type of resection, operative data, and preoperative and postoperative laboratory data. One of 28 patients in the ABC group and nine of 32 patients in the control group had pleural effusion. The incidence was significantly lower in the ABC group than in the control group (P = 0.01). Pleurocentesis was needed in two of the ten patients and thoracic drainage in four patients. CONCLUSION: Application of an ABC to the cut surface of the hepatic ligaments and bare area of retroperitoneum after liver mobilization may prevent postoperative pleural effusion.

Adult↗
PubMed2003

Clinicopathologic evaluation after resection for ductal adenocarcinoma of the pancreas: a retrospective, single-institution experience.

INTRODUCTION: Between April 1992 and December 2000, 167 patients with pancreatic carcinoma were evaluated and treated in our department. One hundred eight patients (64.7%) with pancreatic carcinoma underwent pancreatectomy. Of these patients, 94 had histologically proven ductal adenocarcinoma. The overall postoperative mortality rate was 3.2% (3 patients), and the morbidity rate was 35.1% (33 patients). The estimated 1-, 2-, 3-, and 5-year survival rates were 43.6%, 28.7%, 21.8%, and 12.9%, respectively. There were only six long-term survivors who survived >5 years after surgery. METHODOLOGY AND AIMS: Institutional experience with 94 consecutive patients with ductal adenocarcinoma who underwent pancreatectomy was reviewed to clarify the influence of 29 prognostic factors (5 host, 17 tumor, and 7 treatment factors). Special reference was made to determine whether these significant factors have an effect on long-term survival. Univariate and multivariate models were used to analyze the effect of prognostic factors on survival. RESULTS: Univariate analysis indicated that blood loss, operative time, postoperative complications, histopathologic lymphatic and venous permeation, lymph node metastasis, conclusive stage, conclusive curability, resection margins, serosal invasion, size of tumor, retroperitoneal invasion, major arterial invasion, and mode of histologic infiltration were associated with significantly longer survival (p < 0.05). By Cox proportional hazards survival analysis, the most powerful predictors of outcome were venous permeation, lymph node metastasis, tumor diameter, and conclusive curability. The longest-term survivor had the most advanced stage (stage IV(b)) of disease and curability C. No long-term survivors had all of the good prognostic factors (according to multivariate analysis). CONCLUSIONS: The prognosis after surgical resection of pancreatic carcinoma mostly depends on tumor factors. In this study, it was difficult to identify the determinants of long-term survival in patients with resectable tumors.

Adenocarcinoma↗
PubMed2002

Preoperative laparoscopic examination using surgical manipulation and ultrasonography for pancreatic lesions.

BACKGROUND AND STUDY AIMS: Unnecessary laparotomies in patients with advanced pancreatic disease are unlikely to provide any benefits and may compromise both the quality and duration of survival. The purpose of this study was to determine the contribution of laparoscopy and laparoscopic ultrasound to the diagnosis or staging, or both, of pancreatic lesions. PATIENTS AND METHODS: Fifty-two patients were diagnosed preoperatively with pancreatic cancer. The diagnoses made by laparoscopic ultrasonography (LUS) were compared with those made prior to the operation. Laparoscopic visualization of the body of the pancreas was obtained via an infragastric approach. For the laparoscopic examination of the head of the pancreas, a retroduodenal approach was used. RESULTS: In 52 patients with cancer of the pancreatic head and body, unresectable findings were observed in 13 patients. Portal vein displacement without other unresectable findings was evident in six patients using LUS, and was confirmed at exploratory laparotomy in five patients. The surgical approaches were changed, with seven patients undergoing an open exploration for biliary drainage and the other six patients receiving endoscopic endoprostheses. In six of the 52 patients, LUS-guided needle biopsies and frozen-section examinations detected chronic pancreatitis (n = 4), a malignant lymphoma (n = 1), and an abdominal tuberculosis (n = 1), which were diagnosed preoperatively as pancreatic cancers and cysts. Only one patient undergoing the laparoscopic procedure had acute pancreatitis; this patient was treated conservatively. CONCLUSIONS: LUS, when combined with laparoscopic manipulations, may overcome many of the limitations of laparoscopy alone in the investigation of pancreatic lesions by providing an accurate diagnosis and assessment of the size and extent of the local dissemination.

Adult↗
PubMed2002

[Synchronous tumors consisted of bronchial carcinoid and adenocarcinoma of the lung].

We report a case of synchronous tumors consisted of bronchial carcinoid and adenocarcinoma of the lung. A 58-year-old female was referred to our hospital after screening, because an abnormal shadow was noted in the right lung on her computed tomography (CT) of the chest. CT scans showed a peripheral pulmonary mass in the right middle lobe and a nodule around the right lower lobe bronchus. The nodular lesion like swollen lymph node was diagnosed as bronchial carcinoid originated in B6 by bronchoscopy. The pulmonary mass was diagnosed as adenocarcinoma by using core needle biopsy during operation. Right middle and lower bilobectomy and mediastinal lymph node dissection were performed. Coincidence of a bronchial carcinoid and an adenocarcinoma of the same side of the lung is a rare occurrence.

Adenocarcinoma↗
PubMed2001

FK506, but not cyclosporin A, prevents mitochondrial dysfunction during hypoxia in rat hepatocytes.

Hepatic ischemia/reperfusion injury occurs in the clinical situations including liver transplantation. FK506 and cyclosporin A (CsA) are reported to be hepatotrophic agents in addition to being a powerful immunosuppressive agent. Studies were performed to determine whether the drugs influence a mitochondrial dysfunction under the hypoxic conditions in primary culture model of rat hepatocytes. The Anaeropack system was used for cell culture to create a hypoxia. Cells were treated with FK506 or CsA under the normoxic and hypoxic conditions. Hypoxia markedly decreased intracellular adenosine 5'-triphosphate (ATP) contents and the ketone body ratio (KBR, acetoacetate/beta-hydroxybutyrate) in culture medium as compared with normoxia. FK506 prevented the decreases of ATP contents and the KBR. In contrast, CsA had no effect on either ATP contents or the KBR. FK506, but not CsA, increased the KBR under the normoxic conditions. Under the hypoxic conditions, heat shock protein 70 (Hsp70) was detected after reoxygenation. FK506 enhanced the induction of Hsp70, but CsA again had no effect on Hsp70 induction. These results indicate that FK506 protects the hypoxia injury in part by preventing the mitochondrial dysfunction in concert with the enhancement of heat shock response in hepatocytes.

Adenine Nucleotides↗
PubMed2001

Perioperative blood transfusion in hepatocellular carcinomas: influence of immunologic profile and recurrence free survival.

BACKGROUND: The postoperative recurrence of hepatocellular carcinomas (HCC) associated with perioperative blood transfusion has been the subject of controversy. The authors prospectively investigated the relation between perioperative allogeneic blood transfusions, the recurrence free survival, and the immunologic profiles of patients with HCC who had undergone curative hepatic resections. METHODS: One hundred eight patients were divided into two groups: a transfused group (n = 53) and a nontransfused group (n = 55), according to their perioperative transfusion history. The subsets of lymphoid cells, natural killer cell activity and the phytohemagglutinin (PHA) response were all measured preoperatively, and at 1, 2, and 4 weeks and at 3 and 6 months after the hepatectomy. The recurrence free survival rate then was compared between these two groups. RESULTS: There were no significant differences between these two groups with respect to histologic findings, clinical stage, type of resection, pathologic data, and the recurrence free survival rate. Postoperative levels of the CD8 in the transfused group were elevated as compared with the nontransfused group, and the PHA response of the transfused patients was significantly increased at 7 postoperative days. Natural killer cell activity of the transfused patients was decreased at 7 postoperative days, as compared with the nontransfused patients, but there was no significant difference. CONCLUSIONS: Although allogeneic blood transfusion may have immunosuppressive effects, perioperative blood transfusions did not influence the cancer free survival rate in patients with hepatocellular carcinoma.

Adult↗
PubMed2001

High density O-glycosylation of the MUC2 tandem repeat unit by N-acetylgalactosaminyltransferase-3 in colonic adenocarcinoma extracts.

A synthetic peptide corresponding to the human MUC2 tandem repeat unit was glycosylated in vitro using UDP-GalNAc and extracts of colonic adenocarcinoma and paired normal mucosa, followed by fractionation of the products by reverse phase high-performance liquid chromatography. Several peaks of glycopeptides with different numbers of GalNAc residues attached were detected. It is notable that the adenocarcinoma extract was capable of glycosylating peptides to a much greater extent than was normal mucosa. The levels of mRNA for N-acetylgalactosaminyltransferases-1, -2, and -3 were determined by reverse transcription-PCR. Only N-acetylgalactosaminyltransferase-3 mRNA was expressed at a higher level in the adenocarcinoma than in the normal tissue. When the MUC2 tandem repeat peptide was glycosylated with a mixture of the normal mucosa extract and recombinant N-acetylgalactosaminyltransferase-3, larger amounts of glycopeptides with higher contents of GalNAc residues were produced. The MUC2 tandem repeat peptides glycosylated extensively by recombinant N-acetylgalactosaminyltransferase-1, -2, or -3 were prepared and characterized. Substitution at each Thr residue, as revealed by Edman degradation sequencing, in conjunction with evidence obtained on mass spectrometry indicated a heterogeneous pattern of site-specific glycosylation within the MUC2 tandem repeat. It was found that maximum numbers of 6, 8, and 11 GalNAc residues were incorporated by N-acetylgalactosaminyltransferases-1, -2, and -3, respectively, and that only N-acetylgalactosaminyltransferase-3 could completely glycosylate both consecutive sequences composed of three and five Thr residues in the MUC2 tandem repeat unit. These results suggest that O-glycosylation of the clustered Thr residues is a selective process controlled by N-acetylgalactosaminyltransferase-3 in the synthesis of clustered carbohydrate antigens.

Acetylgalactosamine↗
PubMed2001

Laparoscopic management of bile duct and bowel injury during laparoscopic cholecystectomy.

Accidental injuries to the bile duct and bowel are significant risks of laparoscopic surgery and sometimes require conversion to open surgery. Although some of the injuries related to laparoscopic cholecystectomy can be managed by endoscopic techniques, laparoscopic surgery is not yet sufficiently perfected. We investigated the efficacy of laparoscopic management combined with endoscopic tube or stent insertion in cases of bile duct and bowel injuries during laparoscopic cholecystectomy. Laparoscopic cholecystectomy was attempted on 1,190 consecutive patients between April 1992 and June 1999. The first 70 patients underwent only preoperative intravenous infusion cholangiography (IVC), and the remaining 1,120 patients were subjected to both preoperative IVC and intraoperative cholangiography. We experienced 16 cases of bile duct injury (1.4%). Five patients with circumferential injuries of the bile duct were converted to open surgery for biliary reconstruction. The other 11 patients with partial laceration injuries of the bile duct and biliary leakage from the cystic duct underwent a laparoscopic simple closure technique. In 10 of these patients, an endoscopic tube or stent was inserted on the day after surgery to facilitate biliary decompression and drainage. Bowel injuries occurred in seven patients (0.6%). Three intestinal injuries were due to careless technique, and two duodenal injuries and two intestinal injuries were related to dense adhesions. All of these injuries were successfully repaired using laparoscopic techniques, autosuturing devices, or extracorporeal suturing via the umbilical incision. No postoperative complications were identified. We concluded that the biliary injury site could be closed with a laparoscopic technique so long as the biliary injury was not circumferential. Bowel injuries also could be repaired laparoscopically.

Adolescent↗
PubMed2001

Laparoscopic splenectomy for a lymphangioma of the spleen: report of a case.

We present the first case report of a successful laparoscopic complete excision of a splenic lymphangioma. The splenic tumor was preoperatively diagnosed to be a lymphangioma by the combined modalities of ultrasonography, computed tomography, magnetic resonance imaging, and angiography. A laparoscopic splenectomy was subsequently performed and the pathological examination of the mass confirmed the diagnosis of a lymphangioma. Based on the above findings, a laparoscopic splenectomy is recommended when a splenic tumor is suspected to be either benign or borderline.

Aged↗
PubMed2001

Ruptured dissecting aneurysm in bilateral iliac arteries caused by Ehlers-Danlos syndrome type IV: report of a case.

Ehlers-Danlos syndrome (EDS) is an inherited disorder of connective tissue characterized by hyperextensible skin, hypermobile joints, and abnormalities of the cardiovascular system. Ten types and several subtypes of EDS have so far been recognized based on genetic, clinical, and biochemical characteristics. The spectrum of the disorder varies from mild to life-threatening vascular complications. EDS type IV is a particularly dangerous form with a lethal spontaneous rupture of the major arteries and aneurysmal formation. We present herein a case of a ruptured dissecting aneurysm in the bilateral iliac arteries caused by EDS type IV. A previously healthy 33-year-old man without any physical features of this connective tissue disorder experienced a metachronous vascular rupture two times. Successful synthetic bypass grafting was performed with great difficulty. The diagnosis of EDS type IV was made afterwards based on an electrophoresis analysis of a skin biopsy specimen which revealed a lack of type III collagen. Surgical intervention in cases of arterial complications in EDS type IV patients have been reported to be both difficult and frequently unsuccessful. The early clinical recognition of this syndrome is therefore of great importance due to the hazards of such surgical therapies.

Adult↗
PubMed2001

Laparoscopic cholecystectomy and choledocholithotomy in patients with a previous gastrectomy.

BACKGROUND: An increased incidence of cholelithiasis has been widely reported after truncal vagotomy and after gastric resection. In the early phase of patient selection, previous gastrectomy has been considered a relative contraindication to laparoscopic cholecystectomy (LC). In this study, we examined the management of LC in patients with previous gastrectomy. STUDY DESIGN: LC was attempted on 1,260 consecutive patients. Of these patients, 29 had a previous gastrectomy. Surgical procedures that had been performed included Billroth I gastrectomies (15), Billroth II gastrectomies (10), and total gastrectomies (4). There were 23 cases of cholelithiasis, 4 chronic cholecystitis, 2 gallbladder polyps, I porcelain gallbladder, and I gallbladder cancer. Nine patients were diagnosed with stones in their common bile duct or common hepatic duct. RESULTS: Preoperatively, seven of nine patients with common bile duct stones were subjected to endoscopic sphincterotomy, and the stones were removed successfully from five of these patients. In the remaining two patients, common bile duct stones were removed by laparoscopic choledocholithotomy by choledochotomy. The LC was completed in 26 patients (90%) who had undergone previous gastrectomy. In 449 patients who had previous abdominal surgery without a gastrectomy, only 4 patients (0.9%) required open surgery. In contrast, three patients (10%) with previous gastrectomy required open surgery. No major complications were recorded in this study series, and no residual or retained stones were seen during a followup period of 3 months. CONCLUSIONS: Clear visualization of anatomic structures and landmarks, and scrupulous hemostasis are needed to perform a safe LC in these patients. We conclude that in our study patients, a previous gastrectomy is considered an indication for LC and laparoscopic choledochotomy.

Adult↗
PubMed2001

Cold preservation of rat pancreatic islets just above the freezing point using University of Wisconsin solution.

AIMS: To confirm whether rat islets stored at a temperature just above the freezing point using University of Wisconsin (UW) solution would remain viable for the short term. METHODOLOGY: Rat islets were stored for 24 hours in UW solution, either at 4 degrees C or at -0.6 degrees C (just above the specific freezing point of the UW solution). After cold storage, the islets were assessed for in vitro viability by static incubation and for in vivo viability by a transplantation study. One thousand islets preserved under different conditions were injected intraportally into a streptozotocin-induced diabetic rat as an isograft. Four weeks after the transplantation, an intravenous glucose tolerance test was performed. RESULTS: Islets stored at -0.6 degrees C showed higher insulin secretion rates than those stored at 4 degrees C on a static challenge. The interval from transplantation to the achievement of normoglycemia was also shorter in the -0.6 degrees C group than in the 4 degrees C group. After islet transplantation, the daily nonfasting plasma glucose concentration was higher in the 4 degrees C group than in the -0.6 degrees C group. When compared with the 4 degrees C group, the -0.6 degrees C group showed lower blood glucose values during all investigational periods on an intravenous glucose tolerance test. CONCLUSION: Islet preservation at -0.6 degrees C using UW solution is more advantageous for short term.

Animals↗
PubMed2001

Functional hepatic volume measured by technetium-99m-galactosyl-human serum albumin liver scintigraphy: comparison between hepatocyte volume and liver volume by computed tomography.

OBJECTIVES: We investigated the usefulness of measuring the functional hepatic volume by single-photon emission CT with 99m-technetium galactosyl-human serum albumin scintigraphy (GSA-LV). We then compared this value to the total hepatocyte volume and the hepatic volume determined from CT (CT-LV) in the patients with hepatobiliary tumors. METHODS: Forty-seven patients were divided into two groups, the SM group (subsegmentectomy and monosegmentectomy) and the DT group (disegmentectomy and trisegmentectomy). These groups were further divided into subgroups with or without chronic hepatitis or cirrhosis. The GSA-LV, CT-LV, and the total hepatocyte volume were then calculated. The GSA-LV and CT-LV measurements were performed preoperatively, at 2 and 4 wk, and at 3 and 6 months after surgery. RESULTS: The preoperative GSA-LV values were significantly correlated with the hepatocyte volume and the 15-min retention rate of indocyanine green (ICGR15). Similarly, the hepatocyte volume correlated well with the CT-LV and ICGR15. However, the CT-LV was correlated only with the ICGR15. Recovery of the GSA-LV in the DT group was delayed, and about 90% of the volumetric and functional regeneration was observed within 6 months after the hepatectomy. In contrast, the CT-LV of DT group patients with normal liver remnants returned to approximately 90% of their initial volume within 1 month after the hepatectomy, whereas patients with injured livers regenerated gradually and regained approximately 80% of their preoperative value by 6 months after the hepatectomy. CONCLUSIONS: We conclude that the measurement of functional hepatic volume using the GSA-LV is useful in fully evaluating hepatic function based on hepatocyte volume.

Bile Duct Neoplasms↗
PubMed2001

A new method for tolerance induction: busulfan administration followed by intravenous injection of neuraminidase-treated donor bone marrow.

The portal venous (p.v.) administration of foreign cells induces donor-specific tolerance. Recently, we have demonstrated that the p.v. administration of donor cells elicits donor-specific tolerance across major histocompatibility complex barriers. In the present study, utilizing the intrahepatic tolerance-inducing system, we have established a new method for organ transplantation using both busulfan ([Bu] to provide a sufficient "space" for the donor hematopoietic cells to expand in the recipient) and neuraminidase ([Neu] to enhance the trapping of i.v.-injected cells in the liver). Radiolabeled bone marrow cells (BMCs) were found to exclusively accumulate in the livers of the recipients as a result of the Neu treatment. Furthermore, hematopoietic progenitors (forming hematopoietic foci) in the accumulated BMCs were retained in the recipient livers for at least 18 days. C57BL/6 (B6) mice that had been transplanted with skins of BALB/c mice immediately after the injection of BALB/c BMCs showed a 90% skin graft survival rate over 400 days as a result of using the combination of injecting 50 mg/kg Bu into the B6 mice and treatment of the BALB/c BMCs with 0.25 U/ml Neu (50 Bu + 0.25 Neu). However, the survival rate significantly decreased when either the Bu or Neu treatment was omitted. In tolerant recipients, microchimerism was observed in the various hematolymphoid organs. T cells collected from the tolerant recipients suppressed proliferative responses to the donor-alloantigens but enhanced the production of Th2 and Th3 cytokines. These findings suggest that the enhanced retention of donor BMCs in the recipient livers as a result of the Bu and Neu treatments efficiently induces tolerance induction. Therefore, this "single-day protocol" would be of great advantage for human organ transplantation.

Animals↗
PubMed2001

Enzymatic characterization and interspecies difference of phenol sulfotransferases, ST1A forms.

Cytosolic sulfotransferases, which mediate activation and detoxification of both endogenous and exogenous compounds, consist of at least five different gene families (ST1 to ST5) in mammals. Several cDNAs corresponding to ST1A forms have been reported, but their functional properties are not well characterized. In addition, only a single form of ST1A sulfotransferase has been reported in each experimental animal species despite the expressions of plural forms in humans. Therefore, enzymatic properties of human ST1A3, ST1A5, rat ST1A1, mouse St1a4, and newly isolated rabbit ST1A8 have been characterized and compared by use of their recombinant proteins to clarify the functional difference between human and experimental animal ST1A forms. From the results using more than 25 phenolic chemicals, all the experimental animal ST1A forms showed substrate specificities similar to human ST1A3 rather than ST1A5. They showed high affinities toward p-nitrophenol and 6-hydroxymelatonin as found in human ST1A3. These forms also showed high activities toward umbelliferone and naringenin, but very low activities toward catecholamines, representative substrates of human ST1A5. Hepatic contents of experimental animal ST1A forms varied (66-250 pmol/mg of cytosolic protein) but showed the same order as observed with human ST1A3 (120 pmol/mg). Hepatic content of human ST1A5 was about 19-fold less than that of ST1A3. Therefore, ST1A forms identified in experimental animal species correspond to human ST1A3 functionally. For chemicals such as troglitazone and 2-amino-4'-hydroxy-1-methyl-6-phenylimidazo[4,5-b]pyridine, clear species differences were detected among the ST1A forms examined.

Amino Acid Sequence↗