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)

We have studied the factors determining the rate of ethanol and acetaldehyde metabolism in a group of 25 alcoholics with varying degrees of liver lesion (from normal liver to cirrhosis) and in six nonalcoholic cirrhotics. In alcoholics the ethanol metabolic rate was related to hepatic function, estimated either by the aminopyrine breath test (r = 0.70, p < 0.001) or the indocyanine green clearance (r = 0.76, p < 0.01), and was independent of the activity of hepatic alcohol dehydrogenase and hepatic blood flow. In nonalcoholic cirrhotics blood acetaldehyde was always below the detection limit (0.5 microM), but elevated levels were found in 14 out of the 25 alcoholics. Alcoholics with elevated blood acetaldehyde showed a significantly higher ethanol metabolic rate than alcoholics with undetectable acetaldehyde (120 +/- 17 mg/kg/hr vs 104 +/- 11 mg/kg/hr, p < 0.02), but no differences were observed in the activities of alcohol and aldehyde dehydrogenases. Peak blood acetaldehyde levels were directly related to the ethanol metabolic rate (r = 0.48, p < 0.02), but not to activities of hepatic alcohol or aldehyde dehydrogenases. These results indicate that in chronic alcoholics the main determinant of the ethanol metabolic rate is hepatic function, while the rise of blood acetaldehyde is mainly dependent on the ethanol metabolic rate. Alcohol and aldehyde dehydrogenase activities do not seem to be rate-limiting factors in the oxidation of ethanol or acetaldehyde.
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PMID:Determinants of ethanol and acetaldehyde metabolism in chronic alcoholics. 845 8

Alcohol abuse can induce brain atrophy, but it only occurs in some alcoholics. To investigate whether genetic polymorphism of alcohol-metabolizing enzymes [including alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)] was related to alcoholic brain atrophy, we determined restriction fragment-length polymorphisms of the ADH2 and ALDH2 genes in 77 male alcoholics. Computed tomography was used to determine the severity of brain atrophy. Digestion with MaeIII and MboII after polymerase chain reaction amplification showed that the ADH2(1) gene frequency was significantly higher in patients with brain atrophy than in those without brain atrophy (chi 2 = 9.274, p < 0.01), whereas no significant association was observed between brain atrophy and the ALDH2 gene Multivariate analysis (including age, total alcohol intake, liver cirrhosis, and ADH2 genotype) showed that the ADH2(1)/ADH2(1) genotype was associated with alcoholic brain atrophy. These findings suggest that the ADH2(1) allele may be associated with alcoholic brain atrophy.
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PMID:Association of restriction fragment-length polymorphisms in the alcohol dehydrogenase 2 gene with alcoholic brain atrophy. 865 84

It is still not clear why some alcoholic patients acquire certain organ-specific complications of alcoholism whereas other alcoholic patients acquire different ones. As we know the liver alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and cytochrome P4502E1 (P4502E1) are polymorphic at the ADH2, ADH3, and ALDH2 loci and the 5'-flanking region of the P4502E1. The aim of this study was to investigate the differences between Chinese alcoholic patients with cirrhosis and acute pancreatitis by studying the genetic polymorphisms of ADH2, ADH3, ALDH2, and P4502E1. Genotyping of ADH2, ADH3, ALDH2, and P4502E1 was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods on peripheral white blood cell DNA from 75 alcoholic cirrhotic patients, 48 acute alcoholic pancreatitis patients, 19 heavy drinkers without liver disease or pancreatitis, and 235 controls. The results showed that the frequencies of the alleles ADH2*1 and ALDH2*1 in the alcoholic cirrhotic patients were significantly higher than those in the nonalcoholic controls. In acute alcoholic pancreatitis patients, only the frequency of allele ALDH2*1, not ADH2*1 was significantly higher than in the nonalcoholic controls. The allele frequency of ADH2*1 in acute pancreatitis patients was significantly lower (P < .01) than in alcoholic cirrhotic patients. The daily amount of alcohol consumption was significantly lower in patients with acute pancreatitis than in patients with cirrhosis (P < .0005). The genotype distributions of P4502E1, detected by RsaI and PstI, were not different among alcoholic cirrhotic patients, alcoholic pancreatitis patients, heavy drinker, and nonalcoholic controls. In conclusion, ALDH2*1 is the most important alcohol metabolizing gene affecting predisposition to alcoholism whereas the ADH2*2 gene may influence susceptibility to acute alcoholic pancreatitis. The patients with alcohol-induced cirrhosis and with alcohol-induced acute pancreatitis are of two different subpopulations.
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PMID:Alcoholism and alcoholic organ damage and genetic polymorphisms of alcohol metabolizing enzymes in Chinese patients. 898 75

Recent human genetic studies suggest that a predisposition to alcohol abuse and/or to develop alcoholism may be inherited. Pedigree analysis, linkage, and association studies have helped to detect marker loci and candidate genes that may prove useful in identifying individuals at risk. In particular, molecular genetic research into the causes of alcoholism has drawn attention to the potentially important role of alcohol- and acetaldehyde-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Functional polymorphisms have been observed at various genes encoding these enzyme proteins, all of which act to alter the rate of synthesis of the toxic metabolite acetaldehyde, or decrease its further oxidation. The occurrence of functional polymorphisms in alcohol-metabolizing enzymes makes them favored candidate genes suitable for further molecular genetic research. A positive selection of such genetic polymorphisms in some populations might act as a protective factor against alcohol abuse and alcohol-related disease outcomes. For example, individuals who show initial sensitivity to alcohol by virtue of their genetically controlled abnormality of ALDH2*2 allele are discouraged from excessive alcohol consumption. On the other hand, persons with the heterozygous ALDH2*2 genotype (ALDH2*1/2*2) are at higher risk for developing alcohol abuse-related end-organ damage than those with a homozygous ALDH2*1/2*1 genotype. Moreover, the frequency of C2 allele of cytochrome P45 02E1 was found to be higher in patients with nonfibrotic alcoholic liver disease than in patients with severe hepatic fibrosis or liver cirrhosis. Identification of putative alcoholism vulnerability genes by direct analysis of candidate genes and genetic linkage may therefore help improve approaches to prevention and treatment.
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PMID:Molecular genetic aspects of alcohol metabolism and alcoholism. 921 68

Alcohol is oxidized to acetaldehyde by alcohol dehydrogenase (ADH) and cytochrome P-4502E1 (CYP2E1), and then to acetate by aldehyde dehydrogenase (ALDH). Polymorphisms of these ethanol-metabolizing enzymes may be associated with inter-individual difference in alcohol metabolism and susceptibility to alcoholic liver disease. We determined genotype and allele frequencies of ALDH2, CYP2E1, ADH2, and ADH3 in male Korean patients with alcoholic cirrhosis (n=56), alcoholics without evidence of liver disease (n=52), and nondrinkers (n=64) by using PCR or PCR-directed mutagenesis followed by restriction enzyme digestion. The prevalences of heterozygous ALDH2*1/*2 plus homozygous ALDH2*2/*2 in patients with alcoholic cirrhosis (7.1%) and alcoholics without evidence of liver disease (3.8%) were significantly lower than that in nondrinkers (45.3%). The c2 allele frequencies of the CYP2E1 in alcoholic cirrhosis, alcoholics without evidence of liver disease, and nondrinkers were 0.21, 0.20, and 0.20, respectively. Allele frequencies of ADH2*2 in the three groups were 0.78, 0.74, and 0.77 and those of ADH3*1 were 0.94, 0.98, and 0.95. Therefore, we confirmed the observation that the ALDH2*2 gene protects against the development of alcoholism. However, the development of cirrhosis in Korean alcoholic patients was not associated with polymorphisms of ethanol-metabolizing enzymes.
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PMID:Association between polymorphisms of ethanol-metabolizing enzymes and susceptibility to alcoholic cirrhosis in a Korean male population. 1174 56

Apoptosis plays an important role in the progression of alcohol-induced liver disease to cirrhosis. Oxidative stress is an early event in the development of apoptosis. The major aim of this study was to study the conditions in which oxidative stress occurs in chronic alcoholism and its relationship with apoptosis of hepatocytes. We have found that oxidative stress is associated with chronic ethanol consumption in humans and in rats, in the former independently of the existence of alcohol-induced liver disease. Ethanol or acetaldehyde induces apoptosis in hepatocytes isolated from alcoholic rats, but not in those from control rats. Inhibition of aldehyde dehydrogenase, but not of cytochrome P450 2E1, prevents ethanol-induced cell death. Ethanol-induced apoptosis is caused by increased reactive oxygen species (ROS) driven by increased availability of the reduced form of nicotinamide-adenine dinucleotide (NADH) owing to mitochondrial acetaldehyde metabolism and it is prevented by blocking the opening of mitochondrial permeability transition (MPT) pores with cyclosporine A. Inhibition of nitric oxide (NO) synthase or addition of antioxidant vitamins C and E completely prevented ethanol-induced apoptosis. Mitochondrial oxidative stress, which occurs during chronic alcoholism, renders hepatocytes susceptible to apoptosis. On the other hand, the CD95 ligand expression was up-regulated by acetaldehyde. In conclusion, ethanol induces apoptosis via 2 different pathways: MPT and up-regulation of the expression of CD95-Fas ligand. The overproduction of ROS by mitochondria, driven by acetaldehyde metabolism, is a common trigger of both mechanisms.
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PMID:Mitochondrial oxidative stress and CD95 ligand: a dual mechanism for hepatocyte apoptosis in chronic alcoholism. 1198 71

Early esophageal squamous cell carcinoma detected by esophageal iodine staining can be easily treated by endoscopic mucosectomy, and identifying its predictors is important in better selecting candidates to screen for this high-mortality cancer. The common etiologies of elevated mean corpuscular volume (MCV) and esophageal cancer, including folate deficiency, smoking, drinking and high acetaldehyde exposure, suggest testing MCV as such a predictor. Japanese alcoholic men with (n = 65) and without (n = 206) esophageal squamous cell carcinomas, excluding those with liver cirrhosis, were assessed for MCV within 7 days of their last drink, alone or in combination with findings from either the alcohol flushing questionnaire or genotyping to identify inactive aldehyde dehydrogenase-2 (ALDH2*1/2*2) and the less-active form of alcohol dehydrogenase-2 (ADH2*1/2*1), which pose risks for esophageal squamous cell carcinoma. MCV was higher in cancer patients than in the control group. MCV was higher in both groups in those who were heavier smokers, had lower body mass index (BMI), experienced alcohol flushing, and had ALDH2*1/2*2. After adjusting for age, drinking and smoking habits, BMI and ALDH2/ADH2 genotypes, macrocytosis of MCV > or =106 fl was associated with increased risk for esophageal cancer (OR = 2.75). Men with both MCV > or =106 fl and alcohol flushing had an even higher cancer risk (OR = 5.51). The combinations of MCV > or =106 fl with ALDH2*1/2*2 or ADH2*1/2*1 alone, and both ALDH2*1/2*2 and ADH2*1/2*1 (ORs = 11.44, 21.22 and 319.7, respectively) showed consistently higher risk than the corresponding group with MCV <106 fl (ORs = 7.24, 4.71 and 27.01, respectively). In conclusion, MCV measurement, alone or in combination with the markers of alcohol sensitivity, provides a new means of predicting risk for esophageal squamous cell carcinoma in Japanese alcoholic men.
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PMID:Macrocytosis, a new predictor for esophageal squamous cell carcinoma in Japanese alcoholic men. 1294 54

Alcohol has been known to be associated with an increased risk of cancer. We investigated the characteristics of hepatocellular carcinoma (HCC) in heavy drinkers with negative serum markers for viral hepatitis (non-B, non-C) to determine whether ethanol enhances the development of HCC in Japanese patients with or without serum markers for viral hepatitis. Among the 432 HCC cases seen at our hospital between 1995 and 2000, 26 patients had negative serum markers (non-B, non-C) and were heavy drinkers. The mean patient age at the time of HCC diagnosis was [Formula: see text] years. The mean total ethanol intake was [Formula: see text] kg. Most of the patients also had liver cirrhosis (LC), although the frequency was significantly higher in non-B, non-C, heavy drinkers HCC cases than in non-B, non-C, non-alcoholic HCC cases. Among the hepatitis C virus (HCV)-positive cases, the mean age at the time of HCC diagnosis was lower in heavy drinkers; this trend was not seen in HBV-positive cases. In HCC cases with heavy drinking, a high frequency of gastrointestinal (oropharynx, esophagus, stomach, colon and anal) cancers was seen. As for the aldehyde dehydrogenase-2 (ALDH2) genotype, the frequency of normal homozygotes was 87.5% in heavy drinkers with HCC and the frequency of heterozygotes was 12.5%; the frequency of heterozygotes was 58.3% in alcoholics with esophageal cancer. More than half of the non-B, non-C, heavy drinkers HCC cases had a normal range of serum alpha-fetoprotein (AFP) levels. These results indicate that heavy drinking enhances HCV-related hepatocarcinogenesis. Whether or not ethanol is directly involved in hepatocarcinogenesis remains controversial, but LC may progress HCC in heavy drinkers even if their serum markers for HBV (including tissue) or HCV are negative. Therefore, close observation, including radiographic examinations, is recommended for non-B, non-C, heavy drinkers with LC. In HCV-positive cases, abstinence or a reduction in daily ethanol intake is recommended.
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PMID:Hepatocellular carcinoma in heavy drinkers with negative markers for viral hepatitis. 1504 Sep 57

While the vast majority of heavy drinkers and individuals with obesity, insulin resistance, and the metabolic syndrome will have steatosis, only a minority will ever develop steatohepatitis, fibrosis, and cirrhosis. Genetic and environmental risk factors for advanced alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) seem likely to include factors that influence the severity of steatosis and oxidative stress, the cytokine milieu, the magnitude of the immune response, and/or the severity of fibrosis. For ALD, the dose and pattern of alcohol intake, along with obesity are the most important environmental factors determining disease risk. For NAFLD, dietary saturated fat and antioxidant intake and small bowel bacterial overgrowth may play a role. Family studies and interethnic variations in susceptibility suggest that genetic factors are important in determining disease risk. For ALD, functional polymorphisms in the alcohol dehydrogenases and aldehyde dehydrogenase alcohol metabolising genes play a role in determining susceptibility in Oriental populations. No genetic associations with advanced NAFLD have been replicated in large studies. Preliminary data suggest that polymorphisms in the genes encoding microsomal triglyceride transfer protein, superoxide dismutase 2, the CD14 endotoxin receptor, TNF-alpha, transforming growth factor-beta, and angiotensinogen may be associated with steatohepatitis and/or fibrosis.
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PMID:Genes or environment to determine alcoholic liver disease and non-alcoholic fatty liver disease. 1703 1

Although a relationship between vinyl chloride monomer (VCM) and liver cirrhosis has been reported, the underlying mechanisms are not clear. Cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2) and glutathione S-transferase theta 1 (GSTT1) enzymes are involved in activation and detoxification of VCM, and thus may be important determinants of interindividual susceptibility to VCM-induced liver damage, including liver cirrhosis. The objective of this study was to evaluate if metabolizing genetic polymorphisms could modify individual susceptibility to liver fibrosis of the VCM exposure. CYP2E1, ALDH2, and GSTT1 polymorphisms were determined by the PCR-RFLP method among 320 workers who were employed in five polyvinyl chloride manufacturing plants. Cumulative VCM exposure levels for study subjects were calculated using a job exposure matrix model. Thirteen workers were diagnosed as having liver fibrosis by using ultrasonography. We observed a dose-response trend between VCM exposure and liver fibrosis. Regarding the results on genetic polymorphisms, CYP2E1 c2c2 genotype showed a significant increase in the risk of liver fibrosis as compared to those with CYP2E1 c1c1 or c1c2 genotypes. No differences were observed between GSTT1 and ALDH2 genotypes and liver fibrosis. In summary, our result suggests that genetic polymorphism in CYP2E1 may be responsible for individual differences in susceptibility to liver fibrosis with regard to chronic VCM exposure. Thus, polymorphism analysis of metabolizing enzymes might be useful in the risk assessment of liver damage in workers with VCM exposure.
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PMID:Effect of the CYP2E1 genotype on vinyl chloride monomer-induced liver fibrosis among polyvinyl chloride workers. 1765 24


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