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2. YilmazY,DolarE,UlukayaE,AkgozS,KeskinM,KiyiciM,etal.Solubleforms of extracellular cytokeratin 18 may differentiate simple steatosisfrom nonalcoholic steatohepatitis. World J Gastroenterol 2007;13:837-844.3. Yilmaz Y, Ulukaya E, Gul OO, Arabul M, Gul CB, Atug O, et al. De-creased plasma levels of soluble receptor for advanced glycation endprod-ucts (sRAGE) in patients with nonalcoholic fatty liver disease. ClinBiochem 2009; doi:10.1016/j.clinbiochem.2009.02.003.4. Yoneda M, Uchiyama T, Kato S, Endo H, Fujita K, Yoneda K, et al.Plasma Pentraxin3 is a novel marker for nonalcoholic steatohepatitis(NASH). BMC Gastroenterol 2008;8:53.5. Younossi ZM, Jarrar M, Nugent C, Randhawa M, Afendy M,Stepanova M, et al. A novel diagnostic biomarker panel for obesity-related nonalcoholic steatohepatitis (NASH). Obes Surg 2008;18:1430-1437.

Acute liver failure (ALF) has various causes and is characterized by rapid hepatocyte dysfunction with development of encephalopathy in the absence of preexisting liver disease. Whereas most patients require liver transplantation to prevent the high mortality, some patients recover spontaneously and show complete liver regeneration. Because of the low incidence of ALF, however, the molecular mechanisms of liver dysfunction and regeneration are largely unknown. In this study, we investigated the role of apoptosis and caspases in 70 ALF patients using novel biomarkers that allow the detection of caspase activation in serum samples. Compared with healthy individuals, activation of caspases was strongly enhanced in ALF patients. Interestingly, patients with spontaneous recovery from ALF revealed a significantly higher activation of caspases than patients that required transplantation or died, although in the latter patients extensive DNA fragmentation and signs of nonapoptotic cell death were observed. In the spontaneous survivors, increased caspase activation was accompanied by elevated levels of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), important cytokines involved in liver regeneration. Conclusion: Our data suggest that caspase activation and apoptosis are involved in ALF of patients with spontaneous recovery, whereas caspase-independent cell death might be more relevant in irreversible forms of liver failure. These findings might be important for therapeutic options of ALF but also suggest that measurement of caspase activation might be of prognostic value to predict the outcome of acute liver failure. (HEPATOLOGY 2008.)

Hepatic involvement in hereditary hemorrhagic telangiectasia (HHT) is highly variable and may lead to severe clinical symptoms such as heart failure. This controlled, prospective study defined sonographic criteria for hepatic involvement in HHT. Color Doppler sonography and pulsed Doppler sonography were used to study 25 patients with HHT and liver involvement, 20 patients with HHT without liver involvement, 25 patients with cirrhosis, and 25 patients without liver disease. The diagnosis of hepatic manifestation was confirmed by computed tomography and/or angiography. Liver size, parenchymal changes of the liver, vessel diameters, and flow velocities of the portal vein and the hepatic artery were determined. Resistance index (RI) and pulsatility index (PI) were calculated. The diameter of the common hepatic artery was significantly dilated without overlap between HHT patients with liver involvement and the 3 control groups (mean 11.3 +/- 2.8 mm [HHT with liver involvement], 4.6 +/- 0.9 mm [HHT without liver involvement], 4.8 +/- 1.0 mm [cirrhosis], and 4.4 +/- 1.0 mm [healthy controls], P.001). Doppler parameters of the proper hepatic artery differed significantly (all P.001). In all patients with HHT and liver involvement, areas with intrahepatic hypervascularization caused by dilated intrahepatic arteries were observed in varying intensity. Cardiac output significantly correlated with the diameter of the common hepatic artery (r = 0.53, P =.007) and the portal vein (r = 0.42, P =.05). In conclusion, the diameter of the common hepatic artery (7 mm) and intrahepatic hypervascularization are suitable sonographic diagnostic parameters of HHT with high sensitivity and specificity. Dilated diameters of the hepatic feeding vessels are indicators for systemic circulatory distress in these patients.

Rat hepatic stellate cells (HSC) cultured in serum-containing medium underwent a rapid (3-hour) classical induction of p50:p65 and p65:p65 nuclear factor-kappaB (NF-kappaB) dimers. Subsequent culturing was associated with prolonged expression of active p50:p65 and persistent induction of a high-mobility NF-kappaB DNA binding complex consisting of potentially novel Rel-like protein(s). Formation of the latter complex was competed for by specific double-stranded oligonucleotides, was up-regulated by treatment of HSCs with tumor necrosis factor alpha (TNF-alpha), and was maintained at basal levels of expression by a soluble HSC-derived factor. An NF-kappaB-responsive CAT reporter gene was highly active in early cultured HSCs but was also trans-activated at a lower but significant level in longer-term cultured cells and could be completely suppressed by expression of dominant negative IkappaB-alpha. Physiological significance of the lower persistent NF-kappaB activities was also demonstrated by the ability of long-term cultured HSCs to support the activity of the NF-kappaB-dependent human intercellular adhesion molecule-1 (ICAM-1) promoter. Freshly isolated HSCs expressed high levels of IkappaB-alpha and IkappaB-beta. Culture activation was accompanied by a long-term reduction in levels of IkappaB-alpha with no detectable expression in the nuclear fraction of cells, under these conditions p50:p65 was detected in the nucleus. IkappaB-beta expression was transiently reduced and, upon replenishment, was associated with appearance of a lower-mobility IkappaB-beta antibody-reactive species. Bcl3 expression was absent in freshly isolated HSC but was induced during culturing and became a persistent feature of the activated HSC. Inhibition of NF-kappaB DNA binding activity by gliotoxin was associated with increased numbers of apoptotic cells. We suggest that activation of NF-kappaB in cultured HSC is required for expression of specific genes associated with the activated phenotype such as ICAM-1 and may be antiapoptotic for rat HSCs.