Loss of Survivin influences liver regeneration and is associated with impaired Aurora B function.

The chromosomal passenger complex (CPC) acts as a key regulator of mitosis, preventing asymmetric segregation of chromosomal material into daughter cells. The CPC is composed of three non-enzymatic components termed Survivin, the inner centromere protein (INCENP) and Borealin, and an enzymatic component, Aurora B kinase. Survivin is necessary for the appropriate separation of sister chromatids during mitosis and is involved in liver regeneration, but its role in regenerative processes is incompletely elucidated. Whether Survivin, which is classified as an inhibitor of apoptosis protein (IAP) based on domain composition, also has a role in apoptosis is controversial. The present study examined the in vivo effects of Survivin ablation in the liver and during liver regeneration after 70% hepatectomy in a hepatocyte-specific knockout mouse model. The absence of Survivin caused a reduction in the number of hepatocytes in the liver, together with an increase in cell volume, macronucleation and polyploidy, but no changes in apoptosis. During liver regeneration, mitosis of hepatocytes was associated with mislocalization of the members of the CPC, which were no longer detectable at the centromere despite an unchanged protein amount. Furthermore, the loss of survivin in regenerating hepatocytes was associated with reduced levels of phosphorylated Histone H3 at serine 28 and abolished phosphorylation of CENP-A and Hec1 at serine 55, which is a consequence of decreased Aurora B kinase activity. These data indicate that Survivin expression determines hepatocyte number during liver development and liver regeneration. Lack of Survivin causes mislocalization of the CPC members in combination with reduced Aurora B activity, leading to impaired phosphorylation of its centromeric target proteins and inappropriate cytokinesis.

[Role of vitamin K antagonists from a hepatologist's point of view]. / Rolle der Vitamin-K-Antagonisten aus Sicht des Hepatologen.

Vitamin K antagonists are often used as oral anticoagulants for primary and secondary prevention of thromboembolic events. Vitamin K antagonists induce an anticoagulant effect by interfering with the vitamin K metabolism in the liver. Well-known complications are bleeding events and skin necrosis. Recent data indicate increasing numbers of cases with hepatic complications due to vitamin K antagonists ranging from mild hepatopathy to acute liver failure with high mortality. Hepatotoxicity is usually developed after a few months of latency, which is associated with unspecific symptoms, jaundice, elevated transaminase levels as well as cholestatic enzymes. Hepatotoxicity due to vitamin K antagonists is seldom; however, it should be considered in cases of elevated liver enzymes. In this case coumarin therapy should be discontinued. Caution is needed when changing to another coumarin derivative because cross-reactivity has been described.

A Rare Case of Propofol-Induced Acute Liver Failure and Literature Review.

The incidence of drug-induced acute liver failure is increasing. A number of drugs can inhibit mitochondrial functions, alter ß-oxidation and cause accumulation of free fatty acids within the hepatocytes. This may result in hepatic steatosis, cell death and liver injury. In our case, propofol, an anesthetic drug commonly used in adults and children, is suspected to have induced disturbance of the mitochondrial respiratory chain, which in consequence led to insufficient energy supply and finally liver failure. We report the case of a 35-year-old Caucasian woman with acute liver failure after anesthesia for stripping of varicose veins. Liver histology, imaging and laboratory data indicate drug-induced acute liver failure, presumably due to propofol. Hepatocyte death and microvesicular fatty degeneration of 90% of the liver parenchyma were observed before treatment with steroids. Six months later, a second biopsy was performed, which revealed only minimal steatosis and minimal periportal hepatitis. We suggest that propofol led to impaired fatty acid oxidation possibly due to a genetic susceptibility. This caused free fatty acid accumulation within hepatocytes, which presented as hepatocellular fatty degeneration and cell death. Large scale hepatocyte death was followed by impaired liver function and, consecutively, progressed to acute liver failure.

Liver transplantation in swine without venovenous bypass.

INTRODUCTION: A model of orthotopic liver transplantation in swine was developed to investigate an advanced reperfusion approach. Thereby, we consciously disclaim otherwise commonly practiced venovenous bypass during the recipient operation. MATERIAL AND METHODS: Ten liver transplantations were performed according to the described technique without using venovenous bypass. In each swine the observation period was 48 h. RESULTS: All transplantations were carried out after a median cold ischemic time of 307.5 min (295-340); the median warm ischemic time in these cases was 25 min (20-32). Eight of 10 swine survived 48 h after the operation. CONCLUSION: Orthotopic liver transplantations in the recipient swine are feasible even without using venovenous bypass.