Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nonenzymatic conjugation of metabolites is decreased in chronic diseases of the liver, which is caused by decreased concentration of glutathione. The activities of glutathione enzymes are increased, this indicating the development of compensatory processes of mobilization of the second phase of detoxication, that is, increased conjugation under conditions of suppression of the cytochrome P-450 system. Measurement of liver glutathione transferase is a highly informative test for assessing the activity of the pathological process, particularly important in patients with chronic active hepatitis and cirrhosis of the liver.
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PMID:[Activities of glutathione enzymes in liver biopsy specimens in chronic lesions of hepatocytes]. 962 74

A 68-year-old woman, with type 2 diabetes mellitus, hypercholesterolemia, and prior long-term simvastatin therapy, self-resumed troglitazone after running out of metformin. She developed an acute severe hepatitis with microvesicular steatosis and mysositis. There was subsequent resolution of the myositis but progression of the hepatitis to symptomatic cirrhosis over a period of 12 weeks. Both troglitazone and simvastatin are metabolized by cytochrome P-450 3A4. Troglitazone typically induces metabolism of drugs metabolized by this cytochrome so that simple simvastatin toxicity seems less likely to have been involved. The association with myositis, the severity of the hepatitis with progression to cirrhosis, and the presence of microvesicular steatosis suggests altered mitochondrial metabolism, which has been described with each agent, as the underlying pathogenic mechanism. Although troglitazone (Rezulin) has been withdrawn from the market, other similar agents are available for therapy of type 2 diabetes mellitus. Increased awareness of a potential interaction between these two classes of drugs is warranted.
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PMID:Myositis, microvesicular hepatitis, and progression to cirrhosis from troglitazone added to simvastatin. 1128 Nov 88

Patients with cirrhosis of the liver were found to have a considerable suppression of the system of biotransformation of the liver before operation which correlated with the data of the direct indices of monooxigenase system of hepatocytes--cytochrome P-450 and activity of N-demethylase of amidopyrine. Operative interventions on such patients independent of the type of portosystemic shunting result in considerably decreased content of metabolites of amidopyrine--4AAP and N-ac-4-APP in urine as compared with the preoperative level (p < 0.05). Hyperbaric oxygenation is the optimal stimulator of activity of the liver biotransformation system. Better indicators characterizing the increased metabolic activity of the liver were noted in patients with selective portosystemic anastomoses and hyperbaric oxygenation in the postoperative period.
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PMID:[Some pathogenetic aspects of developing liver failure and preventing it in patients with liver cirrhosis after portosystemic shunting]. 1204 97

Hepatocellular cancer is the fifth most frequent cancer in men and the eighth in women worldwide. Established risk factors are chronic hepatitis B and C infection, chronic heavy alcohol consumption, obesity and type 2 diabetes, tobacco use, use of oral contraceptives, and aflatoxin-contaminated food. Almost 90% of all hepatocellular carcinomas develop in cirrhotic livers. In Western countries, attributable risks are highest for cirrhosis due to chronic alcohol abuse and viral hepatitis B and C infection. Among those with alcoholic cirrhosis, the annual incidence of hepatocellular cancer is 1-2%. An important mechanism implicated in alcohol-related hepatocarcinogenesis is oxidative stress from alcohol metabolism, inflammation, and increased iron storage. Ethanol-induced cytochrome P-450 2E1 produces various reactive oxygen species, leading to the formation of lipid peroxides such as 4-hydroxy-nonenal. Furthermore, alcohol impairs the antioxidant defense system, resulting in mitochondrial damage and apoptosis. Chronic alcohol exposure elicits hepatocyte hyperregeneration due to the activation of survival factors and interference with retinoid metabolism. Direct DNA damage results from acetaldehyde, which can bind to DNA, inhibit DNA repair systems, and lead to the formation of carcinogenic exocyclic DNA etheno adducts. Finally, chronic alcohol abuse interferes with methyl group transfer and may thereby alter gene expression.
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PMID:Risk factors and mechanisms of hepatocarcinogenesis with special emphasis on alcohol and oxidative stress. 1660 31

Non-alcoholic fatty liver disease (NAFLD) is emerging as a common medical problem. Nonalcoholic steatohepatitis (NASH) is the critical turning point at which NAFLD progresses to more advanced stages such as hepatic fibrosis, cirrhosis and even hepatocellular carcinoma. However, the study of the pathogenic or therapeutic factors involved in NASH has been hampered by the absence of a suitable experimental model. The aim of the present work was to establish a high-fat emulsion-induced rat model of NASH. Male Sprague-Dawley rats were fed a high-fat emulsion via gavage for 6 weeks. Animals were examined for weight gain, serum and hepatic biochemistry, insulin sensitivity, hepatic malondialdehyde (MDA), superoxide dismutase (SOD) and tissue morphology, as well as cytochrome P-450 2E1 (CYP2E1) and peroxisome proliferator-activated receptor alpha (PPARalpha) expression in the liver. The results showed that rats treated with high-fat emulsion became obese, demonstrated abnormal aminotransferase activity, hyperlipoidemia, hyperinsulinemia, hyperglycemia and insulin resistance. The model rats exhibited an increased concentration of serum TNF-alpha, total cholesterol (TC), triglyceride (TG), MDA and reduced SOD levels in the liver. Immunoblot analysis showed that the expression of CYP2E1 was increased, whereas PPARalpha was reduced in the NASH model rat liver. Moreover, morphological evaluation revealed that hepatic steatosis, inflammation and mitochondrial lesions were also reproduced in this model. In conclusion, a practical and repeatable new rat model of steatohepatitis was established by feeding with high-fat emulsion via gavage. This model provides a valuable research tool and reproduces many of the clinical indices of human NASH.
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PMID:High-fat emulsion-induced rat model of nonalcoholic steatohepatitis. 1662 32

Over the last three decades, direct hepatotoxic effects of ethanol were established, some of which were linked to redox changes produced by NADH generated via the alcohol dehydrogenase (ADH) pathway and shown to affect the metabolism of lipids, carbohydrates, proteins, and purines. It was also determined that ethanol can be oxidized by a microsomal ethanol oxidizing system (MEOS) involving a specific cytochrome P-450; this newly discovered ethanol-inducible cytochrome P-450 (P-450 IIEi) contributes to ethanol metabolism, tolerance, energy wastage (with associated weight loss), and the selective hepatic perivenular toxicity of various xenobiotics. Their activation by P-450IIEi now provides an understanding of the increased susceptibility of the heavy drinker to the toxicity of industrial solvents, anaesthetic agents, commonly prescribed drugs, over-the-counter analgesics, and chemical carcinogens. P-450 induction also explains depletion (and toxicity) of nutritional factors such as vitamin A. As a consequence, treatment with vitamin A and other nutritional factors is beneficial, but must take into account a narrowed therapeutic window in alcoholics who have increased needs for nutrients and also display an enhanced susceptibility to some of their adverse effects. Acetaldehyde (the metabolite produced from ethanol by either ADH or MEOS) impairs hepatic oxygen utilization and forms protein adducts, resulting in antibody production, enzyme inactivation, and decreased DNA repair. It also stimulates collagen production by the vitamin A storing cells (lipocytes) and myofibroblasts, and causes glutathione depletion. Supplementation with S-adenosyl-L-methionine partly corrects the depletion and associated mitochondrial injury, whereas administration of polyunsaturated lecithin opposes the fibrosis. Thus, at the cellular level, the classic dichotomy between the nutritional and toxic effects of ethanol has now been bridged. The understanding of how the ensuing injury eventually results in irreversible scarring or cirrhosis may provide us with improved modalities for treatment and prevention.
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PMID:Metabolism of ethanol and associated hepatotoxicity. 1684 49

The A1 adenosine receptor positron emission tomography (PET) ligand 8-cyclopentyl-3-(3-[18F]fluoropropyl)-1-propylxanthine ([18F]CPFPX, ) undergoes a fast hepatic metabolism. An optimal design of PET quantitation approaches (e.g., bolus/infusion studies) necessitates the knowledge of factors that influence this metabolism. Metabolites of were separated by radio thin-layer chromatography. Metabolism in vivo, in pooled human liver microsomes and in recombinant human cytochrome isoenzyme preparations was studied. Dynamic PET studies using were performed on three controls and two patients, one treated with the antidepressant and inhibitor of cytochrome CYP1A2 fluvoxamine, the other suffering from liver cirrhosis. CPFPX is metabolized by cytochrome CYP1A2 with high selectivity [KM=1.1 microM (95% confidence interval, or CI, 0.6-2.0 microM) and Vmax=243 pmol min(-1) mg(-1) (95% CI, 112-373 pmol min(-1) mg(-1)) corresponding to 2.4 pmol min(-1) pmol(-1) cytochrome P-450]. This metabolism can competitively be inhibited by fluvoxamine with KI=68 nM (95% CI, 34-138 nM). At least eight compounds found in human plasma and in the CYP1A2 in vitro preparations have an identical migration pattern and account together for >90% and >80% of the respective metabolite yield. Metabolism was considerably delayed in the two patients. In conclusion, is metabolized by cytochrome CYP1A2. Its metabolism is therefore subdued to disease-related or xenobiotic-induced changes of CYP1A2 activity. The identification of the metabolic pathway of 1 allows to optimize image quantification in A1 adenosine receptor PET studies.
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PMID:Metabolism of the A1 adenosine receptor PET ligand [18F]CPFPX by CYP1A2: implications for bolus/infusion PET studies. 1704 69

Morphologic criteria of steatohepatitis are steatosis, ballooning of hepatocytes, often but not constantly associated with Mallory bodies, pericellular fibrosis and inflammation. Liver cirrhosis follows in about 20-50%. With respect to etiology an alcoholic and non-alcoholic type can be distinguished, the latter being a characteristic hepatic lesion associated with the metabolic syndrome (type II diabetes, insulin resistance, obesity, dyslipidemia). Ballooning of hepatocytes as well as Mallory body formation are associated with a disturbance of the keratin intermediate filament cytoskeleton. Mallory bodies are protein aggregates consisting of keratin (particularly keratin 8), p62, a stress-induced adapter protein involved in signal transduction pathways, heat shock proteins, and ubiquitin. Oxidative stress is involved in Mallory body formation. Major sources of oxidative stress in alcoholic and non-alcoholic steatohepatitis are the microsomal biotransformation system (cytochrome P-450) and the mitochondria, together with an impaired antioxidant defense system. Oxidative stress leads to misfolding/unfolding, abnormal phosphorylation of keratins and disturbance of keratin 8: keratin 18 ratio, and thus interferes with intermediate filament assembly. Moreover, impairment of cellular defense against abnormal proteins, i. e. chaperone action and proteasomal degradation, leads to the accumulation of abnormal aggregation--prone keratins (particularly keratin 8) which after ubiquitination associate with the stress-induced ubiquitin-binding protein p62 to form Mallory bodies. Thus, Mallory body formation resembles an "off-folding" protein response of the amyloid type. These pathogenetic principles of the human disease are supported by immunohistochemical and gene expression studies in experimental animals and by transfection experiments in tissue culture cells.
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PMID:[Alcoholic and non-alcoholic steatohepatitis]. 1803 83

Rats were given 1 ml CCl4 per kg body weight subcutaneously 2 times a week, for 16 weeks. The effects of simultaneous phenobarbital (PB) treatment (0.05% in drinking water) on the hepatotoxicity of CCl4 was studied during 16 weeks of treatment. The retardation of growth, the increase in liver weight and mortality were greater in animals receiving both PB and CCl4 than those given CCl4 alone. Cirrhosis was apparent only in animals treated by PB + CCl4. The potentiating effect of PB on CCl4 hepatotoxicity was also seen in hexobarbital sleeping time, the rate of hexobarbital metabolism, and the cytochrome P-450 content in liver microsomes. The inducing effect of PB alone decreased with time both in vivo and in vitro, which suggests an adaptation or some kind of exhaustion of liver to the effects of PB.
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PMID:Effect of phenobarbital on hepatic injury induced by chronic carbon tetrachloride treatment. 1879 59

Aims: This study was designed to determine if vitamin D receptor (VDR), carrier globulin/binding protein (GC), and cytochrome P-450 family 2, subfamily R, polypeptide 1 (CYP2R1) gene polymorphisms are risk factors in the development of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-infected patients from Northeast India. Materials and Methods: A total of 351 HCV-infected patients were enrolled of which 167 were diagnosed with chronic hepatitis C (CHC), 124 with liver cirrhosis (LC), and 60 with HCC together with 102 age- and sex-matched healthy controls. VDR (BsmI, ApaI, and TaqI), GC (rs4588, rs7051), and CYP2R1 (rs10741657) gene polymorphisms were genotyped for all subjects. Statistical data were analyzed using SPSS ver. 22.0. Results: The frequency of the ApaI CC genotype, ApaI C allele, and bAt haplotype of the VDR gene was significantly higher in HCC and LC patients than controls. After adjusting for other covariates (age, gender, platelet count, AST, ALT, serum albumin, and viral load) logistic regression analysis showed that the ApaI CC genotype and bAt haplotype were independent predictors of HCC development. No significant associations was found for the GC and CYP2R1 polymorphisms examined with the occurrence of HCC. Conclusions: The presence of the VDR ApaI CC genotype and bAt haplotype appear to be important indicators in the development of HCC among HCV-infected patients. Larger studies are needed to further clarify and establish this potential causal relationship.
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PMID:Role of VDR, GC, and CYP2R1 Polymorphisms in the Development of Hepatocellular Carcinoma in Hepatitis C Virus-Infected Patients. 3094 19


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