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)

alpha 1-Antitrypsin (AAT) deficiency is associated with predisposition to developing liver cirrhosis in early childhood, and chronic degenerative lung disease in early adult life. The probable molecular basis for the disease associations is known. One of the common variants, Z, has the propensity to form polymers, a phenomenon which is concentration- and temperature-dependent. This results in accumulation of the protein in hepatocytes, the predominant tissue source of AAT, and leads to cell damage. AAT deficiency results in loss of protection in the lung against neutrophil elastase (NE) the major target for AAT. NE is capable of destroying the architecture of the lung, leading to pulmonary emphysema. The disease process is exacerbated by cigarette smoke, which is capable of oxidizing a critical methionine residue at the active site, rendering AAT an inefficient inhibitor of NE. The combination of deficiency and cigarette smoking are critical to the development of pulmonary emphysema. We have identified a mutation in an enhancer sequence which, in all probability, predisposes to disease by a novel mechanism related to diminished expression of AAT during inflammation. Our understanding of the mechanisms of disease should lead to improved therapeutic interventions.
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PMID:Molecular pathology of alpha 1-antitrypsin deficiency and its significance to clinical medicine. 782 May 38

In human and experimental CCl4-liver damage, S-adenosyl-l-methionine-synthetase and/or the intrahepatic content of S-adenosyl-l-methionine, are diminished and in human cirrhosis phospholipid methyltransferase is markedly reduced. Therefore the aim of this study was to investigate the effect of S-adenosyl-l-methionine administration on liver damage induced by 15-day bile duct ligation. Liver damage was analyzed by histological, ultrastructural and biochemical techniques. Biliary obstruction produced an increase in collagen content, dilation of the bile canaliculi and disorganization of mitochondria. These effects were not observed in the bile-duct-ligated group receiving S-adenosyl-l-methionine. Biochemical results showed that bile duct ligation increased serum bilirubins, and alkaline phosphatase and gamma-glutamyl transpeptidase activities. These effects were prevented significantly by S-adenosyl-l-methionine. On the other hand, glycogen content in the liver was depleted while lipid peroxidation was increased by biliary obstruction, S-adenosyl-l-methionine administration prevented these effects. In the bile-duct-ligated group, hepatocyte and erythrocyte plasma membrane Na+/K+ and Ca(2+)-ATPase were lower than in the control group (p < 0.05). Administration of S-adenosyl-l-methionine preserved ATPase activities. The exogenous S-adenosyl-l-methionine supply is probably responsible for restoring transmethylation lost in liver diseases.
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PMID:Protective effect of S-adenosyl-l-methionine on liver damage induced by biliary obstruction in rats: a histological, ultrastructural and biochemical approach. 796 28

The metabolism of sulphur-containing amino acids is impaired in patients with advanced liver disease, but very few data are available in less severe chronic liver disease. We measured fasting plasma levels of methionine, cystine and taurine in 10 healthy subjects and 50 patients with biopsy proven liver disease: chronic persistent/active hepatitis (30 cases), compensated cirrhosis (10 cases) and decompensated cirrhosis (10 cases). Hypermethioninemia (up to 10 times control values) was present only in decompensated cirrhosis. Cystine was markedly reduced in patients with compensated chronic liver disease, while in advanced cirrhosis its concentration was within the normal range. No differences in taurine plasma levels were observed between the various groups. This study suggests that a derangement in sulphur amino acid metabolism, possibly located at various steps along the trans-sulphuration pathway, is also present in mild forms of chronic liver disease.
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PMID:Sulphur amino acid pattern in chronic liver disease. 802 2

Female F-344 rats, in contrast to male rats of the same strain, are largely resistant to the hepatonecrogenic and hepatocarcinogenic actions of a diet devoid of choline and restricted in methionine (CD diet). A study was performed to determine whether the resistance would be overcome by feeding a diet devoid not only of choline, but also of methionine, vitamin B12 and folic acid (MGD diet). Three experiments were performed, to compare the degrees of steatosis and cell death and proliferation, and the onset of pre-neoplastic and neoplastic lesions, in the liver of female F-344 rats fed either the CD or the MGD diet. Limited responses were again observed in rats fed the CD diet. On the other hand, feeding the MGD diet resulted in degrees of steatosis and of compensatory mitogenesis comparable to those previously found to occur in male F-344 rats fed the CD diet. It resulted also in the development of a marked cirrhosis, of neoplastic nodules and of hepatocellular carcinomas. The results indicate that in female F-344 rats overall availability of methyl groups may be more critical than the dietary supply of choline in determining the severity and spectrum of hepatopathology. They emphasize also the importance of compensatory mitogenesis in the induction of neoplastic lesions by methyl-group deficient or devoid diets.
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PMID:On the role of compensatory mitogenesis in the hepatocarcinogenicity of choline and multiple-lipotrope devoid diets. 803 19

To evaluate whether neutrophil bactericidal function, the ability to produce oxygen-derived free radicals, is altered in patients with chronic liver disease, we measured chemiluminescence amplified by a luciferin analog (Cypridina luciferin analog-dependent chemiluminescence) and luminol (luminol-dependent chemiluminescence) in response to N-formyl-Met-Lue-Phe by neutrophils from patients with chronic liver diseases due to C and/or B type hepatitis: chronic active hepatitis, cirrhosis and hepatocellular carcinoma. Both Cypridina luciferin analog-dependent chemiluminescence and luminol-dependent chemiluminescence were significantly decreased in neutrophils from patients with chronic liver disease (hepatocellular carcinoma < cirrhosis < chronic active hepatitis) when they were compared with normal healthy subjects. The reduction of Cypridina luciferin analog-dependent chemiluminescence in chronic active hepatitis and cirrhosis was more sensitive than Cypridina luciferin analog-dependent chemiluminescence; however, in hepatocellular carcinoma, luminol-dependent chemiluminescence was more reduced than luminol-dependent chemiluminescence. Although there were not significant correlations between glutamic pyruvic transaminase and Cypridina luciferin analog-dependent chemiluminescence/luminol-dependent chemiluminescence, there were significant negative correlations between total bilirubin and Cypridina luciferin analog-dependent chemiluminescence/luminol-dependent chemiluminescence. Furthermore, there were significant positive correlations between albumin/prothrombin time and Cypridina luciferin analog-dependent chemiluminescence/luminol-dependent chemiluminescence. These data suggest that an impaired ability to produce oxygen-derived free radicals may contribute to the susceptibility to infection in patients with chronic liver disease.
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PMID:Impaired ability of neutrophils to produce oxygen-derived free radicals in patients with chronic liver disease and hepatocellular carcinoma. 804 92

Patients with liver cirrhosis are characterized by impaired metabolism of amino acids, such as, increased plasma aromatic amino acid (AAA), methionine levels, and decreased plasma branched-chain amino acid (BCAA) levels. These abnormalities are also regarded to induce hepatic encephalopathy, ascitic retention and muscular waste. The etiology of such abnormal amino acid metabolism is multifactorial, i.e. inadequate nutritional intake or protein-restricted diet, disturbed intestinal absorption, hormonal abnormalities and hyperammonemia. In terms of therapy, decreased plasma BCAA level is particularly important, since it is mostly relating to the protein-energy malnutrition. BCAA supplementation seems to be useful to improve plasma amino acid imbalance, protein-energy malnutrition, and subsequently, survival rate of cirrhotic patients.
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PMID:[Impaired metabolism of amino acid and protein in patients with liver cirrhosis]. 811 84

This paper documents dose-dependent effects of ornithine aspartate (OA) on postprandial hyperammonemia and plasma amino acids. Ten patients with cirrhosis were randomized to undergo 1 out of 4 infusion series. Each series consisted of four 8-h infusions (09:00 h-17:00 h), with placebo (NaCl), 5 g, 20 g or 40 g of OA being administered on separate days in varying sequences. This 4-fold crossover design was double-blind. On infusion days, patients received 2 oral protein loads (0.25 g/kg at 09:00 h and 0.5 g/kg at 13:00 h). Venous blood samples were drawn every 2 h and the 24-h urine was collected. In addition to measuring plasma ammonia and amino acids, the urea production rate, serum glucose and serum insulin were analyzed. A significant postprandial rise in the ammonia concentration was noted during the infusions of placebo and 5 g of OA but did not occur with the dosages of 20 g (after the second protein load) and 40 g (after both protein loads). Furthermore, the latter dose, compared with placebo, significantly reduced plasma ammonia after the minor protein load. Urea production rate increased when 20 g or 40 g of OA was administered. Of the amino acids involved in the metabolic pathways of ornithine and/or aspartate, glutamate showed a rise in its plasma level following infusion of 40 g of OA, whereas glutamine did not. Concentrations of methionine, phenylalanine, tyrosine, threonine, serine and glycine declined progressively with increasing doses of OA (5-40 g). The highest dose of the drug caused hyperglycemia and hyperinsulinemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of ornithine aspartate on plasma ammonia and plasma amino acids in patients with cirrhosis. A double-blind, randomized study using a four-fold crossover design. 815 Nov 4

Alcohol causes primary malnutrition by displacing nutrients in the diet and secondary malnutrition via malabsorption and cellular injury through direct cytotoxicity. Hepatotoxicity results from metabolic disturbances associated with the oxidation of ethanol via liver alcohol dehydrogenase (ADH) and the redox changes produced by the generated NADH (the reduced form of nicotinamide adenine dinucleotide), which in turn affects the metabolism of lipids, carbohydrates, proteins, and purines. Ethanol is also oxidized in liver microsomes by an ethanol-inducible cytochrome P450, which contributes to the alcoholic's tolerance and his increased vulnerability to the toxicity of industrial solvents, anesthetics, commonly prescribed drugs, over-the-counter analgesics, chemical carcinogens, and retinoids. Increased acetaldehyde generation, with formation of protein adducts, results in antibody production, enzyme inactivation, decreased DNA repair, impaired utilization of oxygen, glutathione depletion, free radical-mediated toxicity, lipid peroxidation, and increased collagen synthesis. Therapy may eventually improve with the use of supernutrients such as S-adenosyl-L-methionine, which replenishes glutathione, restores methylation, and attenuates liver injury, as well as dilinoleoylphosphatidylcholine, which prevents cirrhosis.
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PMID:Herman Award Lecture, 1993: a personal perspective on alcohol, nutrition, and the liver. 823 56

Levels of plasma amino acids, ammonia, glucagon and insulin and their 5-hr responses to a protein feeding were evaluated before and sequentially (3 mo and 1 yr) after distal splenorenal shunt in 10 patients with cirrhosis belonging to Child-Pugh's class A or B. An index of glucagon effectiveness (plasma glucose/glucagon) was also calculated. These parameters were related to liver test results, portal vein diameter and mental state, and they were compared with those found in seven patients undergoing sclerotherapy of esophageal varices with comparable liver function (control group). Liver test results and levels of plasma insulin did not change in either group. Shunt significantly increased levels of fasting tyrosine, methionine, ornithine, arginine, histidine, ammonia and glucagon with respect to the control group; it also significantly decreased levels of leucine, valine, glucagon effectiveness and portal vein diameter. The elevation of levels of tyrosine, ammonia and the sum of arginine and ornithine was correlated directly with the increase in glucagon and inversely with the decline in glucagon effectiveness. Tyrosine increase was also correlated with the reduction of portal vein diameter. One shunted patient showed mild hepatic encephalopathy. Protein feeding did not worsen the mental state of patients before and after the operation. Surgery significantly increased the 5-hr response to the meal of gluconeogenic amino acids; its rise was again correlated with the changes in glucagon plasma levels and effectiveness. Although the absorptive levels of plasma ammonia were significantly higher 1 yr after surgery, its 5-hr response barely rose. In cirrhotic patients with a relatively preserved liver function, distal splenorenal shunt progressively worsened the fasting plasma profile of nitrogen compounds and the response to protein ingestion of gluconeogenic amino acids. The decline of portal blood flow and glucagon effectiveness may be causal factors. Despite this, the "cerebral" tolerance to a moderate oral load of protein was not reduced by surgery.
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PMID:Early and late changes in fasting and absorptive plasma amino acids and ammonia after distal splenorenal shunt in cirrhosis. 829 90

The absolute and relative concentrations of 16 plasma amino acids in 48 mostly dystrophic infants and children (median of age 1 1/2 years) with extrahepatic biliary atresia and mainly stable preterminal cirrhosis were compared with those of controls. Patient plasma amino acid data were analysed statistically for diagnostic usefulness and correlated with standard biochemical quantities of liver function and of liver perfusion. In the patients the total amounts of non-essential and essential amino acids were reduced by 19% and with the same significance (p < 0.0005). Plasma tyrosine was increased (+40%), while taurine (-44%) and branched chain amino acids (+28.8% to -34.7%) were decreased. Methionine values varied widely. In the molar fractional plasma amino acid profile, only alanine, valine, and leucine were decreased, while threonine, methionine, tyrosine, phenylalanine, ornithine, and serine were increased. Discriminate function analysis showed that the plasma amino acid data discriminated 93.8% of the patients from controls. The concentrations of some amino acids in plasma seemed to have been influenced by protein-calorie deficiency in the patients. The valine/tyrosine ratio and the Fischer index (ratio branched chain/aromatic amino acids) were significantly reduced in the patients versus controls (1.54 +/- 0.55 vs 3.08 +/- 0.55 and 1.66 +/- 0.39 vs 3.00 +/- 0.48). A number of significant correlations (range of r: 0.37-0.59, p < 0.05, 30-48 data pairs) were calculated between plasma amino acid data and several standard biochemical quantities of liver function. The statistical analyses also showed that the Fischer index began to decrease gradually and linearly early in the progression of liver failure.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The plasma amino acid profile and its relationships to standard quantities of liver function in infants and children with extrahepatic biliary atresia and preterminal liver cirrhosis. 831 65


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