ABSTRACT
The aim of this study is to determine whether seeded Dacron with autologous venous tissue fragments shows significant 6-keto-prostglandin F 1? (6 K PGF 1? )production after in vivo implantation.The Dacron grafts seeded with autologous venous fragments were implanted into the inferior vene cava(IVC)of the 13 canines as seeded group;and the control group (8 canines),in which grafts were only preclotted with fresh blood. Plasma 6 K PGF 1? and TXB 2 were assessed at different time.All of the specimens explanted at exsanguination were observed with light microscopy and sanning electron microscopy and the amounts of 6 K PGF 1? from the luminal surface were assessed using ridioimmunoassay. The results showed that the total patency rate of the explanted vessels was higher in seeded group (61.5%) than that in control group ( 25% ),and that endothelial cells lined the whole luminal surface of Dacron at the 14th day after operation in seeded group,but thrombus covered the surface of Dacron at the 14th day in control ones. The level of 6 K PGF 1? from plasma and the luminal surface of Dacron grafts in seeded group was higher,but the level of plasma TXB 2 was lower than that in control group. It can be concluded that seeding Dacron with autologous venous fragments makes a new endothelial lining possible at two weeks,and can release more 6 K PGF 1? and thus lead to an improved patency rate of canine IVC reconstructions,so the graft patency might be determined according to the changes of plasma 6 K PGF 1? and TXB 2 level.
ABSTRACT
Objective To establish a new model of acute hepatic failure in canines for bioartificial liver treatment research . Methods Acute hepatic failure was induced by end to side portocaval shunt combined with common bile duct ligation and transection. The survival rate, liver function, ammonia, Fischer's ratio (BCAA/AAA) and pathological change of injury liver were investigated. Results The ammonia, ALT, AKP, total bilirubin and PT were elevated dramatically and Fischer's ratio declined significantly 14 days after the operation. The survival rate of the models decreased with time 14 days after the operation. Pathological examination of liver tissues revealed evidence of cholestasis, inflammation with accumulation of neutrophils, degeneration and necrosis of hepatocytes.Conclusions End to side portocaval shunt combined with common bile duct ligation and transection can produce a satisfactory acute hepatic failure model in canines, which could be used in the study of bioartificial liver.
ABSTRACT
The plasma histamine concentration was elevated from the control level of 1.16? 0.28ng/ml to 11.42?5.2ng/ml 2-5 min after intravenous injection of Serratia mar-cescens endotoxin,and then declined gradually.The level was still slightly higher than the control 4 h later. The plasma noradrenaline(NA)and adrenaline (Ad) concentrations were increased from the control value of 1.13?0.28ng/ml and 1.05 ?0.32ng/ml to 7.33?1.86ng/ml and 10.04? 3.94ng/ml respectively. Six h later they were still significantly elevated.Arterial blood pressure was reduced to 24.16%of the control level 2-5 min after injection and to 69.2% 6 h later.Both cardiac output and cardiac index were decreased, but the peripheral resistance was increased during endotoxin shock. The significant dilatation of arterioles, venules and capillaries of bulbar conjunctiva microcirculation occurred 1-2 min after endotoxin injection, and the blood flow slowed down at the same time.Five min - six h after endotoxin injection arterioles constricted markedly, but capillaries and venules were still congested and distended.From this study, the interrelationship of some changes in the development of endotoxin shock were discussed.Endotoxin caused the congestion in microcirculatiolelen, reduction of blood returning to the heart and reduced peripheral resistance owing to the histamine released in large amounts. Drastic drop in blood pressure resulted in the increase of NA and Ad release reflexly, which led to the constriction of arterioles, the increase of the peripheral resistance and the restoration of the blood pressure to some extent.Since venules and capillaries were distended and congested,blood pressure and cardiac output still remained at lower level all the time during endotoxin shock.