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Biomedical subjects

Y Kawarada

Publications and source records attributed to Y Kawarada.

186 records · Page 11Linked to original sources
PubMedDate not supplied

The remnant liver dysfunction after 84% hepatectomy in dogs.

BACKGROUND/AIMS: We have been investigating the mechanism of remnant liver dysfunction after extensive hepatectomy in a canine model since 1990. This study focused on the role of heat shock protein and hepatocyte apoptosis. METHODOLOGY: Adult mongrel dogs were randomly divided into 3 groups: Group 1, sham operation; Group 2, 70% hepatectomy; and Group 3, 84% hepatectomy. Heat shock protein and hepatocyte apoptosis after hepatectomy were examined by using isolated hepatocytes and Kupffer cells. RESULTS: Heat shock protein significantly increased in Groups 2 and 3, but rose much higher in Group 3. Examination of pure hepatocyte culture showed no apoptosis in Group 2, but significant apoptosis occurred in Group 3. In co-cultures of hepatocytes and Kupffer cells, induction of apoptosis in Group 2 was mild, but it increased earlier and reached very high levels in Group 3. The TNF-alpha level in co-culture supernatant was significantly higher in Group 3 than Group 2. CONCLUSIONS: After extensive (84%) hepatectomy, apoptosis signal transduction predominates over anti-apoptosis signal transduction, despite high expression of heat shock protein in the remnant liver. Accordingly, the cytotoxic mechanism overcomes the cytoprotective mechanism, leading to significant induction of hepatocyte apoptosis and severe liver damage.

Animals↗
PubMedDate not supplied

Preoperative biliary drainage in obstructive jaundice.

BACKGROUND/AIM: Although the role of preoperative percutaneous transhepatic biliary drainage in obstructive jaundice has been the subject of controversy in many other countries, in Japan, almost all surgeons agree that biliary decompression should be performed prior to the surgical treatment in obstructive jaundice. This study was performed in order to determine the role of preoperative percutaneous transhepatic biliary drainage in obstructive jaundice. PATIENTS AND METHODS: We evaluated 238 patients with preoperative obstructive jaundice, and also studied its pathophysiology in experimental animal models. RESULTS: Both of these studies demonstrated that this procedure should be performed if the value of total bilirubin is more than 5 mg/dl, the ICG Rmax value of the future remnant liver is less than 0.4 mg/kg/min, and the duration of jaundice is more than 3 weeks. Preoperative biliary drainage improves the liver function, so that major operations can be safely performed without major complications. CONCLUSIONS: It therefore seems preferable that patients undergo preoperative biliary decompression to reduce serum total bilirubin to below 5 mg/dl, and to improve hepatic and reticuloendothelial functions and hepatic reserve prior to any major surgical operation.

Adult↗
PubMedDate not supplied

Cell biological evaluation of biliary drainage prior to hepatectomy in obstructive jaundice.

BACKGROUND/AIM: The necessity and efficacy of biliary drainage prior to major surgery in patients with obstructive jaundice have been reported in various clinical and experimental studies in Japan. However, it is not enough that Western countries understand the advantage of preoperative drainage. In this study, therefore, cytoprotective effect of preoperative biliary drainage drainage was evaluated using the cell biological technique. MATERIALS AND METHODS: Ten jaundiced dogs and 10 with drainage (after induction of jaundice) were each divided into two groups: those with and those without 40% hepatectomy. Using these four groups, the advantage of biliary drainage before hepatectomy in obstructive jaundice was studied, using isolated hepatocytes and Kupffer cells. RESULTS: In jaundiced dogs, isolated hepatocyte viability and intracellular cyclic AMP concentration were considerably reduced. The bleb formation rate, culture supernatant lipid peroxide and lactate dehydrogenase contents, and plasma thromboxane B2 and 6-keto-PGF1 alpha levels all markedly increased. These changes were more exaggerated in those after hepatectomy. In the dogs with drainage, all of these values were approximated to those in normal animals. The changes following hepatectomy in dogs with drainage were also less pronounced in comparison with jaundiced animals. CONCLUSIONS: These findings suggest that biliary drainage prior to hepatectomy in obstructive jaundice mitigates liver impairment, both at the cellular level and in terms of prostanoid metabolism. It was concluded that preoperative biliary drainage prior to hepatectomy ensures better results for obstructive jaundice.

Animals↗
PubMedDate not supplied

Apoptosis induction in human breast cancer MRK-nu-1 cells by a polyamine synthesis inhibitor, methylglyoxal bis(cyclopentylamidinohydrazone)(MGBCP).

We have investigated the antiproliferative effects of a polyamine synthesis inhibitor, methylglyoxal bis(cyclopentylamidinohydrazone) (MCBCP), on human breast cancer MRK-nu-1 cells. MGBCP inhibited tumor growth of MRK-nu-1 cells in a dose-dependent manner as the polyamine contents in the cells decreased. Moreover, morphological changes indicating blebbing and chromatin condensation were observed in the MGBCP-treated cells, and hypodiploid subpopulations containing apoptotic cells were clearly detected in the profile of flow cytometric analysis. The number of characteristic oligonucleosome-sized fragments also increased as the concentration of MGBCP increased. The apoptotic effects of MGBCP were partially prevented by the addition of exogenous spermine. The results presented here suggest that, in addition to reducing the growth rate, MGBCP can induce apoptotic cell death in MRK-nu-1 human breast cancer cells by the reduction of intracellular concentrations of polyamines.

Antineoplastic Agents↗
PubMedDate not supplied

Duodenal duplication cyst communicating with an accessory pancreatic duct of Santorini.

A 16 year-old girl with recurrent attacks of acute pancreatitis and upper gastrointestinal bleeding was found to have an aberrant pancreatic duct communicating with a duodenal duplication cyst and a pancreatic pseudocyst on endoscopic retrograde pancreatography (ERP). A partial gastrectomy combined with resection of the aberrant pancreas was performed. The patient is doing well without any problems 17 years after surgery. ERP was of great value in diagnosing this rare disease. Gastroduodenal duplication cysts communicating with the pancreatic duct are rare; only 21 cases, including our own, have been reported in the English-language literature since 1958.

Adolescent↗