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Biomedical subjects

S Uemoto

Publications and source records attributed to S Uemoto.

At least 19 recordsLinked to original sources
PubMed1992

A new bioabsorbable material for rat vascular cuff anatomosis: establishment for the long-term orthotopic liver transplantation model.

Rat vascular anastomosis was performed using a newly synthesized bioabsorbable material (LA-GA copolymer) cuffs and the ordinary polyethylene cuffs. The LA-GA copolymer cuff which anastomosed the portal vein and the inferior vena cava were patent and developed no collateral veins even after 6 months, keeping the transplanted liver normal. By contrast, the polyethylene cuff anastomosed portal vein was completely occluded and the collateral veins were highly developed, with the transplanted liver showing the fatty degeneration of hepatocytes and numerous regenerative nodules. It is concluded that the LA-GA copolymer cuff is a suitable material for the short and long term study of rat orthotopic liver transplantation.

Absorption↗
PubMed1992

Clinical application of arterialization of portal vein in living related donor partial liver transplantation.

Arterialization of the portal vein was employed during hepatic arterial reconstruction in our first few clinical experiences of partial liver transplantation using liver grafts obtained from living related donors. This procedure reduced the time required for revascularization of the grafts to about 25 min, and could in fact reduce the ischemic phase of the grafts. Repeated practice of the clinical transplantation technique has shortened the time needed to complete vascular reconstruction, eliminating the need for this procedure in most of our subsequent cases. In many clinical cases, however, there may be emergency situations which require vascular reconstruction, resulting in a prolongation of ischemic phase and the deterioration of the cellular viability of the graft. In such situations, arterialization of the portal vein can be a useful way to prevent the prolongation of the ischemic phase and to rescue the graft.

Arteriovenous Shunt, Surgical↗
PubMed1992

Hepatoblastoma in a 2-year-old girl with trisomy 18.

A very rare case of mosaic type trisomy 18 associated with hepatoblastoma is described. The patient underwent an extended right hepatic lobectomy at 2 years of age, and the resected tumor was diagnosed as a fetal type dominant hepatoblastoma. The results of chromosome analysis demonstrated that in the peripheral blood and skin, the trisomy 18 cells were 80% and 67%, respectively. On the other hand, although virtually 100% of the cells in the normal liver tissue were 46, XX, about one third of the cells were trisomy 18 in the tumor tissue. At 2 years and 9 months after the operation, the patient was generally healthy and had no evidence of recurrence.

Carcinoma, Hepatocellular↗
PubMed1992

An appraisal of pediatric liver transplantation from living relatives. Initial clinical experiences in 20 pediatric liver transplantations from living relatives as donors.

The authors performed 20 liver transplantations from living related donors between June 1990 and July 1991. The 20 pediatric patients (14 biliary atresia, two Budd-Chiari syndrome, one liver cirrhosis after hepatitis C viral infection (HCV hepatitis), 1 progressive intrahepatic cholestasis, 1 liver cirrhosis, 1 protoporphyria) were transplanted with 11 left lobes, eight left lateral segments, and one right lobe. The choice of donors was restricted to the parents of the recipients. The immunosuppressive treatment consisted of FK 506 and steroids. Seventeen recipients are alive, 15 of whom are well and at home. Two recipients, who underwent emergency transplantation, died of postoperative complications. Another recipient died of accidental asphyxia at 6 months after the transplantation. All 20 donors had uneventful postoperative courses and were able to resume their normal social lives. The arterial ketone body ratio (AKBR) increased to above 1.0 within 2 days after the transplantation in all cases. Relatively mild rejection episodes were encountered in only two cases transplanted with ABO-compatible grafts, and these were treated successfully with steroids and FK 506.

Adolescent↗
PubMed1992

Decrease in arterial ketone body ratio indicating graft dysfunction after liver transplantation.

In 3 cases of living related liver transplantation, arterial ketone body ratio (AKBR) showed secondary decrease in the early postoperative period, indicating the graft dysfunction more rapidly and sensitively than other liver function tests. Significance of AKBR for monitoring the graft function in postoperative management after liver transplantation is discussed.

3-Hydroxybutyric Acid↗
PubMed1991

A valved hepatic portoduodenal intestinal conduit for biliary atresia.

Forty-six consecutive patients with biliary atresia were operated on at our institution during the 11-year period between 1978 and 1989. Their ages at operation ranged from 18 to 153 days (mean, 59 days). After dissecting the porta hepatis structures by Kasai operation, a biliointestinal anastomosis was constructed with a valved hepatic portoduodenal intestinal conduit in all cases. The intestinal valve is an intussuscepted muscular valve. Valvular function was examined radiologically. The upper gastrointestinal series demonstrated no reflux of contrast material into the conduit proximal to the valve and liver scintigraphy demonstrated that radioactive isotope drained readily into the duodenum through the valve. Thirty-nine of the forty-six patients (85%) had bile drainage after initial operation. At present 30 patients (65%) are alive without jaundice, 6 (13%) are alive with jaundice, and 10 (22%) are dead. The 5-year jaundice-free survival rate was 64%. Cholangitis occurred in 9 of 39 patients (23%) who had obtained apparent bile drainage: 5 had tractable cholangitis and 4 had refractory cholangitis. Reoperation restored bile flow in 2 of 8 patients who abruptly ceased to have bile drainage without cholangitis. In conclusion, with a valved hepatic portoduodenal intestinal conduit, the incidence of cholangitis was decreased, its medical control became easier, and the survival rate was improved.

Biliary Atresia↗
PubMed1991

A new bioabsorbable material for rat orthotopic liver transplantation.

Rat orthotopic liver transplantation was performed using a newly synthesized bioabsorbable material (LA-GA copolymer) cuffs and the ordinary polyethylene cuffs. The LA-GA copolymer cuff which anastomosed the portal vein was patent and developed no collateral veins even after 6 months, keeping the transplanted liver normal. By contrast, the polyethylene cuff-anastomosed portal vein was completely occluded and the collateral veins were highly developed, with the transplanted liver showing the fatty degeneration of hepatocytes and numerous regenerative nodules. It is concluded that the LA-GA copolymer cuff is a suitable material for the short- and long-term study of rat orthotopic liver transplantation.

Anastomosis, Surgical↗
PubMed1990

Postoperative recovery of mitochondrial function of the human liver graft procured and preserved with University of Wisconsin (UW) solution.

Changes in arterial blood ketone body ratio (KBR) were investigated in 47 human liver transplantations. Of the 20 grafts preserved with University of Wisconsin (UW) solution, 10 had a cold preservation period of less than 10 h (UWS group) and 10 of more than 10 h (UWL group). In 27 other cases, grafts were preserved with EuroCollins (EC) solution for less than 10 h (EC group). In the EC group, KBR increased over 0.7 within 6 h after reperfusion of the graft in 17 cases (63%) and within 24 h in 7 cases (26%). In the 3 other cases, KBR failed to recover, and these patients underwent retransplantation. In the UW group, KBR recovered within 6 h in 13 cases (65%) and within 24 h in 7 cases (35%). There were no significant differences between the UWS and UWL groups. It is shown that the mitochondrial function of liver grafts preserved with UW solution can be well maintained even after extended preservation periods of more than 10 h.

Adenosine↗
PubMed1989

Effect of cyclosporine on oxidative phosphorylation and adenylate energy charge of regenerating rat liver.

The effect of cyclosporin A (CyA) on regenerating liver was investigated in subtotal hepatectomized rats treated with CyA in terms of mitochondrial phosphorylative activity, hepatic energy charge, and serum bilirubin levels. In the CyA-treated hepatectomized group, the energy charge decreased from normal control value of 0.857 to 0.782 at 6 h after hepatectomy. The decreased energy charge, however, gradually increased and returned to 0.842 at 48 h after hepatectomy with no significant changes being observed between CyA-treated and untreated hepatectomized groups. Phosphorylation rate in the CyA-untreated group increased to 142% of the normal control at 24 h and then decreased to 114% at 48 h after hepatectomy. By contrast, phosphorylation rate in the CyA-treated group increased to 144% of the normal control at 24 h, but remained at the high value of 132% (P less than 0.01; compared to the CyA-untreated group) even at 48 h after hepatectomy. Serum total bilirubin levels in the CyA-treated group were significantly higher than those in the CyA-untreated group during all experimental periods. We conclude that CyA does not exert a direct detrimental effect on mitochondrial function and that, despite the marked hyperbilirubinemia induced by CyA, the mitochondrial phosphorylative activity increases adaptively to provide sufficient energy for enhanced ATP-utilizing reactions in an early process of liver regeneration.

Adenine Nucleotides↗
PubMed1989

Changes in blood ketone body ratio with reference to graft viability after liver transplantation in rats.

Arterial blood ketone body ratio (acetoacetate/3-hydroxybutyrate; KBR), which reflects hepatic mitochondrial redox potential, was measured during a 2-week period after orthotopic liver transplantation in three groups of rats: group 1, the isogenic combination of LEW (RT1l) graft to LEW recipient as control; group 2, the allogenic combination of ACI (RT1a) graft to LEW recipient without immunosuppressive treatment: and group 3, the allogenic combination of ACI to LEW with immunosuppressive treatment using cyclosoporin (CyA). Isogenic recipients survived indefinitely. Allogenic recipients in group 2 had severe rejection with a mean survival of 10.3 +/- 0.54 days, while 77.8% of the allogenic recipients in group 3 survived more than 30 days. KBR of rats surviving more than 2 weeks in groups 1 and 3 gradually increased post-transplantation and was maintained at a high level. By contrast, though KBR in group 2 was restored at 3 days, it gradually fell and remained at a significantly low level (P less than 0.001). It is suggested that KBR provides an accurate indicator for evaluating metabolic viability of the critically deteriorating liver graft accompanied by sever rejection.

Animals↗
PubMed1989

Changes in phospholipid composition of the mitochondrial membrane after orthotopic liver transplantation.

Changes in phospholipids and their fatty acid composition in liver mitochondria obtained from allogenic rats with orthotopic liver transplants were measured with and without immunosuppressive treatment. In untreated allogenic rats, mitochondrial phosphorylation activity was severely deteriorated at 8 days after transplantation. A significant change was also found in the amount of cardiolipin compared with other classes of phospholipids. Namely, cardiolipin decreased, and lysodiphosphatidylglycerol and phosphatidylglycerol increased concomitantly. Furthermore, the percentage of linoleic acid in cardiolipin decreased dramatically. Decrease in cardiolipin and changes in its fatty acid composition may be attributed to the deterioration of mitochondrial function upon acute rejection.

Animals↗
PubMed1989

Immunological treatment with low dosage ciclosporin in rat liver allotransplantation.

Ciclosporin (CsA) was administered subcutaneously at a dose of 3 mg/kg body weight/day from the day of operation to 14 days of liver allotransplantation in ACI rat (RT1a) to LEW rat (RT1(l) strain combination. All LEW recipients of ACI liver transplants without immunosuppressive treatment had severe rejection and expired within 12 days. In contrast, 7 out of 9 recipients in the same strain combination with temporary CsA treatment survived indefinitely. Histologically, widespread cellular infiltration and massive hepatocyte necrosis were evident upon autopsy of the recipients without CsA treatment. In contrast, in the surviving rats of the CsA-treated group, mononuclear cell infiltration was restricted to the periportal field and hepatocytes appeared to be normal at 14 days posttransplant. CsA concentrations in whole blood were determined by high-performance liquid chromatography. The trough levels were 788 +/- 48, 621 +/- 76 and 546 +/- 52 ng/ml, at 5, 10 and 14 days posttransplant, respectively. We concluded that this relatively low-dose subcutaneous administration of CsA offered adequate immunosuppression in rat liver allotransplantation in this strain combination.

Animals↗