Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological studies in the developing world are frequently biased by the simultaneous presence of several infectious pathogens. In the present study, we examined the usefulness of circulating markers of oxidative stress and liver fibrosis to investigate the distinct forms of chronic liver inflammations associated with schistosomiasis and viral hepatitis, respectively. The study was performed in a Sudanese population exposed to Schistosoma. Circulating hyaluronic acid (HA) was used as a marker of liver fibrosis; the severity of schistosomiasis was determined by ultrasonic examination; viral hepatitis infection was ascertained by circulating anti-hepatitis antibodies. Serum markers were examined also in Sudanese subjects not exposed to Schistosoma infection and in French control subjects. We found a drastic decrease of lycopene levels in the subjects exposed to schistosomiasis in comparison with non-exposed Sudanese and French control subjects. Retinol, alpha-tocopherol and five carotenoids were unchanged. Lycopene depletion was unlikely to be due to variations of nutritional origin, since the lycopene/beta-carotene ratio was five-fold lower in the population at risk of schistosomiasis than in the other groups. We found that high HA serum levels were associated with severe periportal fibrosis but not with viral infection. Conversely, levels of the oxidized lipid malondialdehyde (MDA) were associated with viral infection but not with the severity of schistosomiasis, even though the two infections had additive effects. We concluded that serum markers are valuable tools for investigating the complex effects of co-existing factors of chronic liver inflammation.
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PMID:Circulating markers of oxidative stress and liver fibrosis in Sudanese subjects at risk of schistosomiasis and hepatitis. 1581 96

Chronic C hepatitis represents a major health problem worldwide, mainly because progression of the tissue damage leads to the development of cirrhosis and hepatocellular carcinoma. In this review we discuss the molecular mechanisms underlying the development of liver fibrosis. In particular we consider some immunologic aspects that regulate the interaction between HCV and the host immune defense. Reflections are made about the roles played by the host capacity to respond to the viral infection during therapy and the consequences of the deposition of extracellular matrix (ECM) proteins leading to the development of fibrosis. The involvement of inflammatory cytokines in regulating the proteolytic remodeling of the liver and the ECM turn-over is essential for the activation of hepatic stellate cells (HSCs), that have an important role in the progression of liver fibrosis. Finally, we analyze one of the aspects involved in the activation of the HSCs, namely the proteolytic remodeling of the surrounding environment.
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PMID:Immunological and molecular aspects of liver fibrosis in chronic hepatitis C virus infection. 1594 44

We report on a 26-year-old man who presented with severe jaundice and elevated serum liver enzyme activities after having received a dose of Twinrix. In his past medical history, jaundice or abnormal liver function tests were never recorded. Following admission, an elevated immunoglobulin G level and antinuclear antibodies at a titer of 320 with a homogenous pattern were found. Histology of a liver biopsy showed marked bridging liver fibrosis and a chronic inflammation, compatible with autoimmune hepatitis. Treatment was started with budesonide and ursodeoxycholic acid, and led to complete normalization of the pathological liver function tests. We believe that Twinrix led to an acute exacerbation of an unrecognized autoimmune hepatitis in our patient. The pathogenesis remains to be clarified. It is tempting to speculate that inactivated hepatitis A virus and/or recombinant surface antigen of the hepatitis B virus -as seen in patients with chronic hepatitis C and unrecognized autoimmune hepatitis who were treated with interferon alpha-might have been responsible for disease exacerbation.
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PMID:Acute exacerbation of autoimmune hepatitis induced by Twinrix. 1599 42

The question addressed here is: does the bile duct reactive component of hepatitis C disease progress during the progression of the disease to cirrhosis? The question is important because if the answer to the question is yes, then an important correllated question is: does the bile duct reactive component contribute to the fibrotic change which leads to cirrhosis? The first question is addressed in the present study of a series of liver biopsies taken at the four stages of liver fibrosis in patients with hepatitis C. Sixty-four patients with hepatitis who had been biopsied for staging purposes were reviewed retrospectively. The liver biopsies were routinely stained with antibodies for liver cells, bile duct cells, activated stellate cells and cells in S phase of the cell cycle and histochemical stains for collagen and basement membrane. Selective biopsies were stained for stem cells and oval cells. There was a progressive increase in metaplastic bile ductules but the increase did not reach a significant level until stages III and IV of fibrosis. There was a positive correlation between the number of ductules formed and the stage of liver fibrosis. The incidence of proliferating metaplastic ductules was low and did not change significantly during the progression of the stage of the fibrosis. Stains for oval cells and stem cells were negative. It is concluded that the answer to the question posed is: bile ductule reaction does increase during the development of cirrhosis caused by hepatitis C but the increase is due to bile ductular metaplasia, not due to proliferation.
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PMID:The role of bile duct reactive change in the pathogenesis of liver fibrosis due to hepatitis C. 1604 6

Non-alcoholic liver steatosis is associated with metabolic syndrome and type 2 diabetes. The prevalence of this condition in type 2 diabetes is estimated to be between 28 and 55%. Non-alcoholic liver steatosis is not a benign disease because of its potential progression to liver fibrosis, cirrhosis and cancer. The Verona diabetes study, a population-based observational study, on 7148 type 2 diabetic patients after 5 years of follow-up has reported an increased risk of death from gastrointestinal diseases, particularly from chronic liver cirrhosis. Moreover, in the same population after 10 years of follow-up a higher risk of mortality from liver cancer was observed and this risk increased significantly in obese patients (body mass index >30 kg/m2). Of note is that obese diabetic patients suffer an even higher prevalence of non-alcoholic liver steatosis. In conclusion, the Verona diabetes study showed an increased risk of mortality from liver cirrhosis and liver cancer in type 2 diabetic patients. Diverse pathophysiological mechanisms can be responsible, i.e. higher alcohol consumption, hepatitis and others but, considering the high prevalence of non-alcoholic liver steatosis in these patients, it is plausible to hypothesize that non-alcoholic liver steatosis may play a significant role in predisposing the liver of diabetics to chronic diseases.
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PMID:Review article: type 2 diabetes and chronic liver disease in the Verona diabetes study. 1622 67

Activated hepatic stellate cells (HSCs) play a key role in the pathogenesis of hepatic inflammation and fibrosis through the production of matrix metalloproteinases (MMPs). Cytokines and growth factors are thought to activate HSCs. TNF-alpha has pleiotropic functions in hepatitis, but its role in liver fibrosis remains elusive. In this study we investigated the regulation of tumor necrosis factor-alpha (TNF-alpha) in the expression of MMPs by HSCs. We also examined whether the immunosuppressant FK506 influences the MMPs expression in human HSCs. Human HSCs, LI90, were treated with TNF-alpha in the presence of FK506. Release of MMPs into culture media, levels of MMP-9 mRNA and activation of NF-kappaB were compared between the cells cultured with or without FK506. Stimulation of human HSCs, LI90 cells, with TNF-alpha caused the induction of pro-MMP-9. Further, TNF-alpha stimulation induced the degradation of IkappaB-alpha and resulted in the transcriptional activation of NF-kappaB. FK506 suppressed this TNF-alpha-induced NK-kappaB activation, alone with pro-MMP-9 mRNA and protein induction, in HSC. TNF-alpha contributes to the perpetuation of liver fibrosis through MMP-9 production from HSCs and that FK506 inhibits the induction of MMP-9 through NF-kappaB pathway suggesting the anti-inflammatory properties of FK506.
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PMID:Immunosuppressant FK506 inhibits matrix metalloproteinase-9 induction in TNF-alpha-stimulated human hepatic stellate cells. 1630 43

HIV co-infection influences the course and natural history of hepatitis B virus (HBV) infection by impairing the quantity and quality of the innate and adaptive immune response. The rates of spontaneous resolution after acute infection and spontaneous anti-HBe and anti-HBs seroconversions are decreased, and levels of HBV replication are increased in HIV-infected patients. A more rapid progression of liver fibrosis and a higher rate of cirrhosis decompensation (but not hepatocellular carcinoma) have been demonstrated in co-infected patients. The risk of HBV-associated end-stage liver disease and liver-related mortality may be increased by HIV co-infection. Antiretroviral therapy may trigger spontaneous anti-HBe and anti-HBs seroconversion and/or a better immune control of HBV replication by restoring adaptive immunity, but can also increase hepatitis flares. Reactivation of chronic hepatitis B has been observed after suspension of anti-retrovirals with anti-HBV activity or after occurrence of HBV resistance to lamivudine. Future research should focus on: the impact of HIV-induced changes in innate and adaptive immune response and modifications induced by anti-retroviral therapy that may impact on progression of advanced chronic hepatitis B; the association between HBV genotype and clinical course of disease; and the role of occult HBV infection as a co-factor with other causes of liver injury.
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PMID:Natural history of chronic hepatitis B in co-infected patients. 1633 21

Taurine is an abundant organic osmolyte with antioxidant and immunomodulatory properties. Its role in the pathogenesis of chronic liver disease is unknown. The liver phenotype was studied in taurine transporter knockout (taut-/-) mice. Hepatic taurine levels were ~21, 15 and 6 mumol/g liver wet weight in adult wild-type, heterozygous (taut+/-) and homozygous (taut-/-) mice, respectively. Immunoelectronmicroscopy revealed an almost complete depletion of taurine in Kupffer and sinusoidal endothelial cells, but not in parenchymal cells of (taut-/-) mice. Compared with wild-type mice, (taut-/-) and (taut+/-) mice developed moderate unspecific hepatitis and liver fibrosis with increased frequency of neoplastic lesions beyond 1 year of age. Liver disease in (taut-/-) mice was characterized by hepatocyte apoptosis, activation of the CD95 system, elevated plasma TNF-alpha levels, hepatic stellate cell and oval cell proliferation, and severe mitochondrial abnormalities in liver parenchymal cells. Mitochondrial dysfunction was suggested by a significantly lower respiratory control ratio in isolated mitochondria from (taut-/-) mice. Taut knockout had no effect on taurine-conjugated bile acids in bile; however, the relative amount of cholate-conjugates acid was decreased at the expense of 7-keto-cholate-conjugates. In conclusion, taurine deficiency due to defective taurine transport triggers chronic liver disease, which may involve mitochondrial dysfunction.
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PMID:Chronic liver disease is triggered by taurine transporter knockout in the mouse. 1642 Dec 46

Liver fibrosis commonly occurs in patients with hepatitis C virus (HCV) infection as a consequence of the chronic liver damage, thus leading to the development of liver cirrhosis. When hepatic stellate cells (HSCs) become active, they play an essential role in liver fibrogenesis. In this study, interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), commonly elevated in chronic C hepatitis, stimulate the production of matrix metalloprotease-9 (MMP-9) by human hepatocytes at a transcriptional and translational level, but the addition of recombinant interferon-alpha2b (rIFN-alpha2b) hampers this effect. Furthermore, a human HSC line is activated in vitro by incubation with human MMP-9 in the presence of collagen I, and this effect is blocked by the MMP inhibitor BB94. A similar activation was observed when incubating HSCs with conditioned medium of hepatocytes previously stimulated with IL-1beta and TNF-alpha but not when using conditioned medium of hepatocytes costimulated with IL-1beta or TNF-alpha together with rIFN-alpha2b. In conclusion, our results show that hepatocytes stimulated by inflammatory cytokines participate in the activation of HSCs via MMP-9 production and that antiviral therapy modulates such activation.
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PMID:Antifibrogenic effect of IFN-alpha2b on hepatic stellate cell activation by human hepatocytes. 1668 58

The development and severity of liver fibrosis in patients with chronic HCV infection can be evaluated best according to the staging of fibrosis in blind liver biopsy. So far there is however no biochemical indicator suggesting advanced fibrosis or progression of fibrosis in chronic HCV infection. In 1997 - 1999 60 adult out-patients (32 women) with chronic HCV infection were examined by blind liver biopsy. The grading of hepatitis was scored according to Knodell and staging of fibrosis according to Desmet. All patients were anti-HCV positive, assessed by the ELISA-3 method and 48/60 had positive HCV RNA in serum. The main risk factor of HCV infection was blood transfusion (67%). Of 27 examined patients 20 (74%) had serotype HCV 1. Staging of fibrosis: histologically confirmed fibrosis was not recorded in 11 patients (18.3%), mild and medium fibrosis was recorded in 25 (42%), severe fibrosis in 14 (23%) and cirrhosis in 10 (17%). With confirmed fibrosis correlated more closely AST serum activity (p < 0.002) than ALT activity (p < 0.03). Steatosis of the liver was found in 25 (42%) patients. The mean age of patients with steatosis was significantly higher than that of patients without steatosis (p < 0.0008). Steatosis was more frequent in patients with fibrosis (p < 0.04), in particularin the age group above 60 years. The development of fibrosis in patients with chronic HCV infection is suggested by permanently elevated activity of both transaminases whereby AST has a higher predictive value than ALT activity. A total of 40% histologically tested patients had the highest staging of fibrosis (3 - 4). Steatosis is in chronic HCV infection a very frequent finding (42%), in particular in patients above 60 years and those with serious fibrosis. The finding of fibrosis should stimulate the initiation of antiviral treatment which can lead to regression of fibrosis and improvement of the histological finding.
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PMID:[Aspartate aminotransferase (AST) more than alanine aminotransferase (ALT) levels predict the progression of liver fibrosis in chronic HCV infection]. 1673 38


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