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Serum Alanine Transaminase (serum + alanine_transaminase)
Selected AbstractsInflammation and drug hepatotoxicity: Aggravation of injury or clean-up mission?,HEPATOLOGY, Issue 5 2005Hartmut Jaeschke BACKGROUND & AIMS Inflammatory mediators released by nonparenchymal inflammatory cells in the liver have been implicated in the progression of acetaminophen (APAP) hepatotoxicity. Among hepatic nonparenchymal inflammatory cells, we examined the role of the abundant natural killer (NK) cells and NK cells with T-cell receptors (NKT cells) in APAP-induced liver injury. METHODS C57BL/6 mice were administered a toxic dose of APAP intraperitoneally to cause liver injury with or without depletion of NK and NKT cells by anti-NK1.1 monoclonal antibody (MAb). Serum alanine transaminase (ALT) levels, liver histology, hepatic leukocyte accumulation, and cytokine/chemokine expression were assessed. RESULTS Compared with APAP-treated control mice, depletion of both NK and NKT cells by anti-NK1.1 significantly protected mice from APAP-induced liver injury, as evidenced by decreased serum ALT level, improved survival of mice, decreased hepatic necrosis, inhibition of messenger RNA (mRNA) expression for interferon-gamma (IFN-gamma), Fas ligand (FasL), and chemokines including KC (Keratinocyte-derived chemokine); MIP-1 alpha (macrophage inflammatory protein-1 alpha); MCP-1 (monocyte chemoattractant protein-1); IP-10 (interferon-inducible protein); Mig (monokine induced by IFN-gamma) and decreased neutrophil accumulation in the liver. Hepatic NK and NKT cells were identified as the major source of IFN-gamma by intracellular cytokine staining. APAP induced much less liver injury in Fas-deficient (lpr) and FasL-deficient (gld) mice compared with that in wild-type mice. CONCLUSIONS NK and NKT cells play a critical role in the progression of APAP-induced liver injury by secreting IFN-gamma, modulating chemokine production and accumulation of neutrophils, and up-regulating FasL expression in the liver, all of which may promote the inflammatory response of liver innate immune system, thus contributing to the severity and progression of liver injury downstream of the metabolism of APAP and depletion of reduced glutathione (GSH) in hepatocytes. [source] Alcohol-induced free radicals in mice: Direct toxicants or signaling molecules?HEPATOLOGY, Issue 5 2001Ming Yin Tumor necrosis factor , (TNF-,) and free radicals are produced in early alcohol-induced liver injury. Recently, pathology caused by alcohol was blocked nearly completely in tumor necrosis factor , receptor 1 (TNF-R1) knockout mice. With this model, it is now possible to evaluate whether free radicals are directly toxic or act as redox regulators of TNF-, production. Specifically, if free radicals were directly toxic, a parallel decrease in free radicals and pathology in TNF-R1 knockout mice would be predicted. If they only affect TNF-, production, radicals would be expected to remain high while pathology is diminished. Accordingly, free radical production in TNF-R1 knockout mice was studied here. The enteral alcohol delivery model used mice lacking TNF-R1 (p55) and wild-type control C57Bl/6J mice. Animals received a liquid diet continuously with either ethanol or isocaloric maltose-dextrin as control for 4 weeks. Urine ethanol levels fluctuated from 10 to 500 mg/dL in a cyclic pattern in mice receiving ethanol. Ethanol elevated liver:body weight ratios, serum alanine transaminase (ALT) levels, and pathology scores in wild-type mice. These parameters were blunted nearly completely in TNF-R1 knockout mice. Ethanol treatment increased free radical production in wild-type mice compared with animals fed a high-fat control diet. There were no differences in intensity of free radical signals regardless of the presence or absence of TNF-R1; however, pathology differed markedly between these groups. These findings are consistent with the hypothesis that free radicals act as redox signals for TNF-, production and do not directly damage cells in early alcohol-induced hepatic injury. [source] Hepatitis B e antigen seroconversion after lamivudine therapy is not durable in patients with chronic hepatitis B in KoreaHEPATOLOGY, Issue 4 2000Byung-Cheol Song It has been suggested that hepatitis B e antigen (HBeAg) seroconversion after lamivudine therapy is durable in Caucasians with chronic hepatitis B (CHB). However, little is known whether it is also durable in endemic areas of hepatitis B virus (HBV) infection. We evaluated the posttreatment durability of lamivudine-induced HBeAg seroconversion and the predictive factors for relapse in Korean patients with CHB. We retrospectively analyzed 98 HBeAg-positive patients with CHB who were treated with lamivudine between August 1996 and December 1997. Lamivudine was given at a dose of 150 mg per day. After HBeAg seroconversion, lamivudine was continued for an additional 2 to 4 months, and posttreatment monitoring continued for up to 24 months. HBeAg seroconversion was achieved in 34 of the 98 patients (34.7%). The mean duration of treatment in these seroconverters was 9.3 ± 3.0 months. During the follow-up period, the cumulative relapse rates at 1 year and 2 years posttreatment were 37.5% and 49.2%, respectively. Most relapses were accompanied by elevation of serum alanine transaminase (94%) and reappearance of HBeAg (81%). Pretreatment serum HBV DNA levels and the duration of additional lamivudine therapy after HBeAg seroconversion were 2 independent predictive factors for posttreatment relapse. In conclusion, lamivudine-induced HBeAg seroconversion was not durable in this endemic area. And the duration of additional lamivudine therapy after HBeAg seroconversion significantly affected the posttreatment relapse. Further studies are needed to determine the duration of lamivudine and to elucidate the cause of high relapse after HBeAg seroconversion in endemic areas of HBV. [source] Prednisolone Priming Enhances Th1 Response and Efficacy of Subsequent Lamivudine Therapy in Patients With Chronic Hepatitis BHEPATOLOGY, Issue 3 2000Yun-Fan Liaw M.D. Asian lamivudine trial has shown that hepatitis B e antigen (HBeAg) seroconversion rate during 1 year of lamivudine therapy was only 16% but was 64% in the subgroup of patients with a pretherapy serum alanine transaminase (ALT) level over 5 times the upper limit of normal (ULN). To test whether ALT rebound following corticosteroid priming enhances response to lamivudine therapy, a pilot study was conducted in 30 patients with ALT levels less than 5× ULN (43-169; N < 36 U/L). They received 30 mg of prednisolone daily for 3 weeks, 15 mg daily for 1 week, no treatment for 2 weeks, and then 150 mg of lamivudine daily for 9 months. Complete response (CR) was defined as ALT normalization with HBV-DNA seroclearance and HBeAg seroconversion. Peripheral blood mononuclear cell proliferation and cytokine secretion in response to recombinant HBV core antigen were serially assayed in 7 patients during priming and after withdrawal of prednisolone. Clinical rebound with an ALT over 5× ULN was observed in 20 patients (67%). Of these 20, 12 (60%) showed CR as compared with 1 (10%) of the 10 patients without significant ALT rebound (P < .002). The HBeAg seroconversion sustained in 70% of the patients 3 to 6 months after the end of lamivudine therapy. Immunological assays revealed that the responders showed Th1 dominant response and higher stimulation index to prednisolone priming. No serious side effect was encountered. These results suggest that corticosteroid priming induced immune/ALT rebound greatly enhances response to lamivudine therapy in chronic hepatitis B. Confirmation by randomized controlled trial is needed. [source] Estrogen is involved in early alcohol-induced liver injury in a rat enteral feeding modelHEPATOLOGY, Issue 1 2000Ming Yin The aim of this study was to investigate whether reduction in blood estrogen by removal of the ovaries would decrease the sensitivity of female rats to early alcohol-induced liver injury using an enteral ethanol feeding model, and if so, whether estrogen replacement would compensate. Livers from ovariectomized rats with or without estrogen replacement after 4 weeks of continuous ethanol exposure were compared with nonovariectomized rats in the presence or absence of ethanol. Ethanol increased serum alanine transaminase (ALT) levels from 30 ± 6 to 64 ± 7 U/L. This effect was blocked by ovariectomy (31 ± 7) and totally reversed by estrogen replacement (110 ± 23). Ethanol increased liver weight and fat accumulation, an effect that was minimized by ovariectomy and reversed partially by estrogen replacement. Infiltrating leukocytes were increased 6.7-fold by ethanol, an effect that was blunted significantly by ovariectomy and reversed by estrogen replacement. Likewise, a similar pattern of changes was observed in the number of necrotic hepatocytes. Blood endotoxin and hepatic levels of CD14 messenger RNA (mRNA) and protein were increased by ethanol. This effect was blocked in ovariectomized rats and elevated by estrogen replacement. Moreover, Kupffer cells isolated from ethanol-treated rats with estrogen replacement produced more tumor necrosis factor , (TNF-,) than those from control and ovariectomized rats. It is concluded, therefore, that the sensitivity of rat liver to alcohol-induced injury is directly related to estrogen, which increases endotoxin in the blood and CD14 expression in the liver, leading to increased TNF-, production. [source] Synergistic antiviral effect of a combination of mouse interferon-, and interferon-, on mouse hepatitis virusJOURNAL OF MEDICAL VIROLOGY, Issue 2 2003Uichiro Fuchizaki Abstract Although interferon (IFN)-, and IFN-, have been reported to exhibit a synergistic antiviral effect through the different signaling pathways in vitro, their therapeutic efficacy is not well defined in vivo. The current study was carried out to investigate the combined antiviral effect in a model of mouse hepatitis virus Type 2 (MHV-2) infection, in which fulminant hepatitis is developed. MHV-2 was injected intraperitoneally into 4-week-old ICR mice, IFN or the vehicle was administered intramuscularly for 5 days, and the antiviral effect was evaluated based on survival periods, liver histology, serum alanine transaminase (ALT) levels, and MHV-2 virus titers in the liver tissues. The animals in the group treated with a combination of IFN-, and IFN-, survived for longer periods than the groups treated with IFN-, alone and IFN-, alone (IFN-, 103 (IU/mouse)/-, 103 vs. IFN-, 103, P,<,0.005; IFN-, 103/-, 103 vs. IFN-, 103, P,<,0.001). This is consistent with the lower levels of hepatocellular necrosis and serum ALT and the decreased titers of MHV-2 virus in the liver tissues (48 hr, P,<,0.001; 72 hr, P,<,0.001). These findings indicate that a combination of IFN-, and IFN-, exhibits a synergistic antiviral effect on MHV-2 infection. The biology of MHV-2 is quite different from that of human hepatitis viruses; however, these results suggest the beneficial combined therapy of IFN-, and IFN-, for the treatment of human viral hepatitis. J. Med. Virol. 69:188,194, 2003. © 2003 Wiley-Liss, Inc. [source] Anti-Inflammatory and Anti-Apoptotic Roles of Endothelial Cell STAT3 in Alcoholic Liver InjuryALCOHOLISM, Issue 4 2010Andrew M. Miller Background:, It is generally believed that the hepatoprotective effect of interleukin-6 (IL-6) is mediated via activation of signal transducer and activator of transcription 3 (STAT3) in hepatocytes. IL-6-deficient mice are more susceptible to alcohol-induced hepatocyte apoptosis and steatosis and elevation of serum alanine transaminase (ALT); however, whereas hepatocyte-specific STAT3 knockout mice are more susceptible to alcohol-induced hepatic steatosis, they have similar hepatocyte apoptosis and serum ALT after alcohol feeding compared with wild-type mice. This suggests that the hepatoprotective effect of IL-6 in alcoholic liver injury may be mediated via activation of STAT3-independent signals in hepatocytes, activation of STAT3 in nonparenchymal cells, or both. We have previously shown that IL-6 also activates STAT3 in sinusoidal endothelial cells (SECs). Thus, the purpose of this study was to investigate whether STAT3 in endothelial cells also plays a protective role in alcoholic liver injury. Methods:, Wild-type and endothelial cell-specific STAT3 knockout (STAT3E,/,) mice were pair-fed and fed ethanol containing diet for 4 weeks. Liver injury and inflammation were determined. Results:, Feeding mice with ethanol-containing diet for 4 weeks induced greater hepatic injury (elevation of serum ALT) and liver weight in STAT3E,/, mice than wild-type control groups. In addition, ethanol-fed STAT3E,/, mice displayed greater hepatic inflammation and substantially elevated serum and hepatic levels of IL-6 and TNF-, compared with wild-type mice. Furthermore, ethanol-fed STAT3E,/, mice displayed a greater abundance of apoptotic SECs and higher levels of serum hyaluronic acid than wild-type controls. Conclusions:, These data suggest that endothelial cell STAT3 plays important dual functions of attenuating hepatic inflammation and SEC death during alcoholic liver injury. [source] Plasma transforming growth factor-,1 level and efficacy of ,-tocopherol in patients with non-alcoholic steatohepatitis: a pilot studyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2001T. Hasegawa Background: Non-alcoholic steatohepatitis is a distinct entity, characterized by fatty change, lobular inflammation and fibrosis of the liver. Some cases of non-alcoholic steatohepatitis progress to cirrhosis, but it is not easy to distinguish this disease from non-alcoholic fatty liver by non-invasive examinations. No proven therapy for non-alcoholic steatohepatitis exists. Transforming growth factor-,1 is implicated in the development of liver fibrosis, and is inhibited by ,-tocopherol (vitamin E) in the liver. Therefore, in this study, the significance of the measurement of the level of plasma transforming growth factor-,1 and the effect of ,-tocopherol on the clinical course of non-alcoholic steatohepatitis were investigated. Methods: Twelve patients with non-alcoholic steatohepatitis and 10 patients with non-alcoholic fatty liver, with a diagnosis confirmed by liver biopsy, were studied. None of the patients had a history of alcohol abuse, habitual medicine or malignant or inflammatory diseases. All patients were negative for hepatitis B, C and G virus. Patients were given dietary instruction for 6 months, and then ,-tocopherol (300 mg/day) was given for 1 year. Blood chemistries, measurement of plasma transforming growth factor-,1 level and liver biopsies were undertaken before and after the 1-year ,-tocopherol treatment. Results: The serum alanine transaminase level decreased in non-alcoholic fatty liver patients, but not in non-alcoholic steatohepatitis patients, after 6 months of dietary therapy. Although the serum alanine transaminase level in non-alcoholic steatohepatitis patients was reduced during the 1-year ,-tocopherol treatment, ,-tocopherol had no effect on the serum alanine transaminase level in non-alcoholic fatty liver patients. The histological findings, such as steatosis, inflammation and fibrosis, of the non-alcoholic steatohepatitis patients were improved after ,-tocopherol treatment. The plasma transforming growth factor-,1 level in non-alcoholic steatohepatitis patients was significantly elevated compared with that in non-alcoholic fatty liver patients and healthy controls, and decreased, accompanied by an improvement in serum alanine transaminase level, with ,-tocopherol treatment. Conclusions: lOur data suggest that the measurement of the level of plasma transforming growth factor-,1 represents a possible method of distinguishing between non-alcoholic steatohepatitis and non-alcoholic fatty liver. Long-term ,-tocopherol treatment may be safe and effective for non-alcoholic steatohepatitis. A randomized, controlled, double-blind trial is needed to confirm the full potential of ,-tocopherol in the management of non-alcoholic steatohepatitis. [source] | ||||||||||