| Chapter I Establishment and evaluation of the model of acute liver failure in the cynomolgus monkeyObjective:A stable and reproducible model of acute liver failure(ALF)in large animals is an indispensable tool for the research of artificial liver.The study in the chapter I of this dissertation aims at establishing a drug-induced and surgical ALF model in cynomolgus monkey respectively.Methods:1.16 cynomolgus monkeys were randomly divided into four groups(A,B,C,D)which received an intravenous administration of D-galactosamine(D-gal)at a dose of 0.30,0.25,0.20 + 0.05(interval of 24 h),0.20 g/kg respectively.The clinical manifestations and survival time of the animals was observed and recorded.Blood samples were collected for assessment of blood biochemistry and coagulation.ICP and liver pathological changes were also compared between the four groups.2.Six monkeys underwent portal-right renal venous shunt combined with common bile duct ligation and transection(PRRS + CBDLT).Afer the operation,the status of the animals was observed and recorded.Blood samples were collected for assessment of blood biochemistry and coagulation,and specimens of liver were obtained for pathological and immunohistochemical examination.Results:1.All the experiment monkeys rapidly presented as ALF characterized by a lassitude,inappetence and jaundice of varying degrees.The suvival time of the animals in group A,B,and C were respectively 56 ± 8.7 h,95 ± 5.5 h and 99 ± 2.2 h.And all the monkeys in group D survived except one monkey which survived for 136 hours.The level of serum liver enzyme,TBiL,Cr,BUN and blood Amm of the D-gal treated monkeys were significant increased and serum ALB level were decreased.In addition,experiment monkeys showed a prolonged prothrombin time and increased ICP after administration of D-gal.The histological assessment of the liver in dead monkeys showed an obvious patchy necrosis and hemorrhage.2.Postoperatively,the monkeys had progressively increased listlessness,loss of appetite,and obvious jaundice.Blood biochemistry levels(Amm,ALT,AST,TBiL,CK,LDH,DBiL,ALP)and prothrombin time(PT)were significantly increased,and albumin(ALB)was markedly reduced compared with baseline values.Histological examination of liver specimens on postoperative day 10 revealed inflammation with denaturation and necrosis of hepatocytes as well as loss of hepatocyte architecture.Conclusion:Respectively,a D-gal induced ALF model and a novel surgical model through portal-right renal venous shunt combined with common bile duct ligation for ALF in the cynomolgus monkey were successfully established.Chapter Ⅱ The safety and effectiveness evaluation of bioartificial liver support system implanted with microencapsulated porcine hepatocytesObjective:To construct a bioartificial liver support system(BALSS)base on turning type perfusion bioreactor that has the independent knowledge property right and implanted with microencapsulated porcine hepatocytes.Then to evaluate its safety and effectiveness through the treatment of ALF model in cynomolgus monkey and lay a foundation for the further clinical trials.Methods:ALF models in the cynomolgus monkey was induced by an intravenous administration of D-galactosamine at a dose of 0.20 + 0.05(interval of 24 h).Hepatocytes of Tibet mini-pig were isolated using two-step perfusion method.After beening enclosed in alginate-polylysine-alginate(APA)microcapsules,Porcine hepatocytes were then implanted with turning type perfusion bioreactor to construct a BAL system which was used to treat ALF model in cynomolgus monkey.15 ALF models of cynomolgus monkey were randomly divided into three groups:(1)an ALF group(blank control group):model animals only received intensive care;(2)a BAL group:model animals were treated with BAL system loading with microencapsulated porcine hepatocytes;(3)a Sham group(device control group):model animals were treated for six hours with BAL system containing cell-free microencapsulation.Survival time and changes of blood biochemistry indices,PT,ICP of the monkeys before and after treatment were compared in three groups.Results:All the ALF monkeys were well tolerated throughout the treatment.Compared with the two control groups,survival time of the animals in BAL group were respectively prolonged for 14 and 16 hours.Model animals in the BAL group also showed an significantly lower levels of liver enzyme,TBiL,Amm and lower value of ICP,which indicated an obvious liver support efficacy.Conclusion:The bioartificial liver support system implanted with microencapsulated porcine hepatocytes can improve the blood biochemical indices as well as ICP and prolong survival time of ALF cynomolgus monkey. |
