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Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of procollagen prolyl hydroxylase was measured in fibrotic liver obtained from mice with hepatosplenic schistosomiasis, an animal model of the most prevalent form of human liver fibrosis. Measurable activity of prolyl hydroxylase in fibrotic liver supernatants was 47-fold higher than that of normal liver. The effect of prolyl hydroxylase inhibition on collagen synthesis in fibrotic liver slices was studied, using 8,9-dihydroxy-7-methyl benzo[b]quinolizinium bromide (GPA 1734). This compound was shown in other systems to inhibit prolyl and lysyl hydroxylations by iron chelation at concentrations which did not affect total protein synthesis. The formation of nondialyzable labelled hydroxyproline was inhibited by GPA 1734, 40, 70 and 95% at 30, 50 and 100 micrometer, respectively. Incorporation of proline into total liver protein was unaffected at 30 and 50 micrometer, but was inhibited 20% at 100 micrometer GPA 1734. Underhydroxylated collagen synthesized by liver slices with GPA 1734 was extracted with neutral salt solution and was subsequently hydroxylated with partially-purified prolyl hydroxylase to the same extent as control material synthesized in the absence of GPA 1734.
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PMID:Liver collagen hydroxylation in murine schistosomiasis. 20 35

The present study has been performed in order to establish the relative and combined roles of ethanol and malnutrition on liver Fe, Zn, Cu, and Mn alterations in alcoholic male adult Wistar rats, and also the relationships between these alterations and histomorphometrically determined hepatocyte and nuclear areas, perivenular fibrotic rim area, and total amount of fat present in the liver. Four groups of 8 animals each were fed: (1) a nutritionally adequate diet (C); (2) a 36% ethanol-containing (as percent of energy), isocaloric diet (A); (3) a 2% protein-containing, isocaloric diet (PD); and (4) a 36% ethanol, 2% protein-containing, isocaloric diet (A-PD), respectively, following the Lieber-DeCarli model. Ethanol-fed, protein-deficient animals showed the highest liver Fe, and the lowest Zn and Cu values, although differences in liver Zn, Mn, and Cu values were not significantly different between PD and A-PD groups. Statistically significant differences of these parameters were observed between the A and the A-PD groups, and between the A and PD groups, except for liver iron. Except for liver Mn, differences between C and A groups were statistically significant. These alterations correlated with liver fibrosis and steatosis, serum albumin, and weight loss, except for liver Mn, which was not correlated with fibrosis or steatosis. Thus, protein deficiency seems to enhance ethanol-induced liver Fe, Zn, and Cu alterations, whereas protein deficiency, but not ethanol, seems to play a major role on liver Mn alterations.
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PMID:Combined effects of ethanol and protein deficiency on hepatic iron, zinc, manganese, and copper contents. 141 56

A retrospective study of 127 patients with untreated homozygous genetic hemochromatosis (HGH) was conducted to evaluate the respective roles of iron overload and non-iron-related factors in the development of hepatic fibrosis in HGH. Twenty-seven percent of the patients had cirrhosis, 21% had liver fibrosis and 52% had no fibrosis (prefibrotic group). The mean value of liver iron concentration was increased significantly (p < 0.001) in cirrhotic (378 +/- 144 mumol/g dry wt.) and in fibrotic (331 +/- 168) subjects compared to prefibrotic (237 +/- 108) patients. Of 13 patients with liver iron concentration > or = 500, 12 had liver fibrosis or cirrhosis, versus 48/134 with liver iron concentration < 500. Chronic alcoholic men exhibited hepatic fibrosis or cirrhosis more frequently than non-alcoholic men (p < 0.001). Non-alcoholic men had hepatic fibrosis or cirrhosis more often than non-alcoholic women (p < 0.05). Cirrhotic and fibrotic patients were significantly older than prefibrotic patients whilst a significant correlation between age and liver iron concentration was found in younger patients only. These results suggest that the iron overload threshold necessary to induce fibrosis is modulated by non-iron-related factors such as alcoholism, sex and age. The development of fibrosis in HGH with liver iron concentration < 500 mumol/g is frequent and must lead to a search for associated non-iron-related fibrogenic factors.
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PMID:Liver fibrosis in genetic hemochromatosis. Respective roles of iron and non-iron-related factors in 127 homozygous patients. 148 46

We evaluated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in 78 Italian patients with hereditary hemochromatosis as well as the relation between HCV antibody (anti-HCV) status, hepatitis B surface antigen (HBsAg) and liver histology. None of the patients had been transfused or ever consumed more than 60 g of alcohol per day. Eighteen showed histological signs of chronic hepatitis, active cirrhosis was present in 12, chronic active hepatitis in 4 and chronic persistent hepatitis in 2. Liver fibrosis or cirrhosis without inflammatory activity was observed in 31 subjects, whereas liver histology was normal except for iron overload in 18. The prevalence of HBsAg in the whole series was 5% and of anti-HCV was 20.5%. The prevalence of HBsAg and anti-HCV was significantly higher in the chronic hepatitis group than in the fibrosis/cirrhosis (p = 0.01) and the normal groups (p < 0.01). Fourteen of 18 hereditary hemochromatosis patients with chronic hepatitis were HBsAg (4) or anti-HCV (10) positive and all the latter subgroup had HCV-RNA in their serum as shown by the polymerase chain reaction. Although most of the patients with associated chronic hepatitis had cirrhosis, their serum ferritin levels and amount of mobilizable iron were significantly lower than those of the fibrosis/cirrhosis group (p < 0.01). This indicates that hepatitis viral infection acts synergistically with iron in accelerating the development of liver damage.
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PMID:Liver damage in Italian patients with hereditary hemochromatosis is highly influenced by hepatitis B and C virus infection. 148 15

The precise role of lipid peroxidation in the pathogenesis of alcoholic liver disease is still being debated. To explore the issue, this study was undertaken to investigate the status of lipid peroxidation, antioxidants and prooxidants at two discrete stages of experimental alcoholic liver disease. Male Wistar rats were intragastrically fed a high-fat diet plus ethanol for 5 or 16 wk (the duration that resulted in initiation of centrilobular liver necrosis or liver fibrosis, respectively). Lipid peroxidation was assessed in isolated microsomes and mitochondria with three parameters: malondialdehyde equivalents as determined by thiobarbituric acid assay, conjugated diene formation and 4-hydroxynonenal as a 2,4-dinitrophenylhydrazone derivative. To assess antioxidant systems, hepatic concentrations of glutathione, methionine and alpha-tocopherol were determined. The concentration of nonheme iron, a known prooxidant, was also measured. At wk 5, centrilobular liver necrosis was already evident in the ethanol-fed animals, with two- or threefold increases in plasma AST and ALT levels. At this stage, neither malondialdehyde equivalents nor conjugated diene values were elevated, and the 4-hydroxynonemal level was below 0.2 nmol/mg protein. Hepatic concentrations of methionine and alpha-tocopherol in these animals were increased two- and threefold, respectively, whereas the reduced glutathione level remained unchanged. When alcoholic liver disease had progressed to perivenular or bridging fibrosis at wk 16, all three parameters of lipid peroxidation showed consistent increases that were accompanied by significant reductions in the hepatic glutathione and methionine levels. Interestingly, the control animals pair-fed with the high-fat diet also had significantly elevated 4-hydroxynonenal levels at wk 16 compared to the wk 5 level.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Increased 4-hydroxynonenal levels in experimental alcoholic liver disease: association of lipid peroxidation with liver fibrogenesis. 163 54

Sixteen patients (age range, 3 to 17 years) with transfusion-dependent beta-thalassemia major were studied prospectively, beginning at the onset of chelation therapy with deferoxamine (desferrioxamine). A liver biopsy specimen was obtained from each patient at the start of the study, and periodically thereafter. Liver histologic features, iron content, and iron excretion were assessed during the course of the study. Hepatic iron levels from liver biopsy specimens appeared to correlate well with serum ferritin levels in the younger less heavily iron-loaded patients; however, in patients with higher serum ferritin levels, hepatic iron appeared to reach a saturation level. Fourteen of the 16 patients showed a pattern of marbled fibrosis of the liver in their initial biopsy specimens. Follow-up biopsy specimens from nearly all of the patients showed a substantial reduction in iron concentration, but only two of seven patients showed improvement in the degree of hepatic fibrosis three to five years later. Patients less than 8 years old exhibited a normal pattern of linear growth until approximately the age of 10 years, followed by a progressive decrease to the 30th to 40th percentile. Two patients, aged 18 and 22 years, died of cardiac disease during the study. These findings suggest that chelation therapy in patients with transfusion-dependent thalassemia needs to be initiated at an early age, possibly before 3 years, if significant liver fibrosis and growth impairment are to be effectively prevented.
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PMID:A prospective evaluation of iron chelation therapy in children with severe beta-thalassemia. A six-year study. 334 15

To determine the therapeutic effect of long-term, intensive iron chelation therapy, we studied liver iron content and histology in four children with thalassaemia major during 52-83 months of intensive therapy with desferrioxamine. The initial biopsies obtained prior to or within 21 months after beginning chelation therapy had Grade IV iron staining, with heavy iron deposition present in parenchymal and reticuloendothelial cells. Subsequent biopsies, obtained when serum ferritin levels had fallen to 71-246 micrograms/l, contained Grade 0 or Grade I stainable iron. Little or no iron was present in parenchymal or reticuloendothelial cells. The liver iron concentration, measured by magnetic susceptibility, returned to normal or nearly normal levels. Hepatic fibrosis did not progress during treatment with desferrioxamine. These findings demonstrate that intensive and sustained chelation therapy with desferrioxamine will remove excessive liver iron and preserve hepatocellular structure.
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PMID:Depletion of excessive liver iron stores with desferrioxamine. 647 38

To determine if alcoholic liver fibrogenesis is exacerbated by dietary iron supplementation, carbonyl iron (0.25% wt/vol) was intragastrically infused with or without ethanol to rats for 16 wk. Carbonyl iron had no effect on blood alcohol concentration, hepatic biochemical measurements, or liver histology in control animals. In both ethanol-fed and control rats, the supplementation produced a two- to threefold increase in the mean hepatic non-heme iron concentration but it remained within or near the range found in normal human subjects. As previously shown, the concentrations of liver malondialdehyde (MDA), liver 4-hydroxynonenal (4HNE), and serum aminotransferases (ALT, AST) were significantly elevated by ethanol infusion alone. The addition of iron supplementation to ethanol resulted in a further twofold increment in mean MDA, 4HNE, ALT, and AST. On histological examination, focal fibrosis was found < 30% of the rats fed ethanol alone. In animals given both ethanol and iron, fibrosis was present in all, with a diffuse central-central bridging pattern in 60%, and two animals (17%) developed micronodular cirrhosis. The iron-potentiated alcoholic liver fibrogenesis was closely associated with intense and diffuse immunostaining for MDA and 4HNE adduct epitopes in the livers. Furthermore, in these animals, accentuated increases in procollagen alpha 1(I) and TGF beta 1 mRNA levels were found in both liver tissues and freshly isolated hepatic stellate cells, perisinusoidal cells believed to be a major source of extracellular matrices in liver fibrosis. The dietary iron supplementation to intragastric ethanol infusion exacerbates hepatocyte damage, promotes liver fibrogenesis, and produces evident cirrhosis in some animals. These results provide evidence for a critical role of iron and iron-catalyzed oxidant stress in progression of alcoholic liver disease.
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PMID:Experimental liver cirrhosis induced by alcohol and iron. 761 36

Gerbils administered iron dextran are the only animal species which have been shown to develop hemochromatosis of the liver and heart in the same manner as transfusion dependent homozygous thalassemics. The iron chelating hydroxypyridinone, CP94, has been administered prophylactically to iron overloaded gerbils in a dosing regime which favors the formation of bidentate chelated iron, to examine the possibility of additional toxicity being caused to the liver and heart by the bidentate chelated iron complex. Hepatic iron accumulation was inhibited by CP94 administration for up to 6 weeks, but not after 20 weeks. Iron accumulation in the heart was increased significantly after 6 and 20 weeks of chelator treatment. Pathological changes in both organs were markedly more severe after 20 weeks in chelator treated animals. There was a higher incidence of cardiofibrosis and more extensive liver fibrosis in iron overloaded, chelator treated animals after 20 weeks.
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PMID:Potentiation of iron accumulation in cardiac myocytes during the treatment of iron overload in gerbils with the hydroxypyridinone iron chelator CP94. 781 11

In the intragastric ethanol infusion model using a high fat diet (25% calories as corn oil) and adult Wistar rats, focal centrilobular liver necrosis is evident after five weeks of feeding, and liver fibrogenesis is induced between the 9th and 16th weeks. At the 16th week, fibroproliferative activation of Ito cells, a perisinusoidal cell type believed to be a key player in liver fibrogenesis, can be demonstrated by increased DNA synthesis, enhanced gene expression of collagen, and transforming growth factor-beta 1 (TGF beta 1) by these cells. This stage of alcoholic liver fibrogenesis, but not the earlier stage of liver necrosis, is closely associated with enhanced hepatic lipid peroxidation (LP) as demonstrated by significant correlation between the degree of liver fibrosis and hepatic levels of LP aldehydic products such as malondialdehyde (MDA) and 4-hydroxynonenal (4HNE). The direct role of these aldehydes in alcoholic liver fibrogenesis is supported by in vitro demonstration of stimulation of Ito cell collagen gene expression by MDA and 4HNE as well as in vivo confirmation of the importance of the aldehydes in iron-catalyzed potentiation of alcoholic liver fibrogenesis. Induced cytochrome P4502E1 is considered as a primary site of enhanced oxidative stress, and compromised glutathione homeostasis is suggested to underlie, in part, the net increase in hepatic LP. These findings are in support of our working hypothesis that enhanced LP is a critical pathogenetic event for alcoholic liver fibrogenesis.
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PMID:Oxidative stress, antioxidants, and alcoholic liver fibrogenesis. 812 1


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