Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Percutaneous liver biopsies obtained from patients with a history of chronic alcoholism and normal liver, fatty liver, alcoholic hepatitis, or active cirrhosis were incubated with tritiated proline to determine the pattern of collagen biosynthesis in these conditions. Incorporation of labeled proline and hydroxyproline into salt-soluble and insoluble fractions of collagen was evaluated by radiochemical analysis and tissue localization documented by autoradiography. Biopsy specimens of alcoholic hepatitis and cirrhosis exhibit a significant increase in the amount of radioactive proline and hydroxyproline in salt-soluble and insoluble collagen. Marked accumulation of radioactivity occurred over bile ducts, fibroblasts, and collagen fibers in the portal area and over hepatocytes, fibroblasts, and collagen fibers in the centrilobular area. Fatty liver is associated with an increase in uptake of proline and hydroxyproline in the salt-soluble fraction of collagem; silver grains appear in the periphery of fat-laden cells and in areas of focal inflammation. Digestion by collagenase indicates that labeling over fibroblasts and collagen reflects active synthesis, whereas, entry of proline into the cell protein pool is responsible for accumulation of radioactivity in other sites. In vitro ethanol causes a significant increase in the incorporation of proline and hydroxyproline into collagen in biopsy specimens of alcoholic hepatitis or active cirrhosis, but has no effect on collagen synthesis by normal or fatty liver.
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PMID:Collagen biosynthesis in liver disease of the alcoholic. 117 Feb 67

One of the contributory factors to the development of cirrhosis is a decrease in collagenase activity, which may be related to levels of inhibitors such as serum tissue inhibitor of metalloproteinase. We therefore measured serum tissue inhibitor of metalloproteinase and serum procollagen III peptides (another proposed marker of fibrosis) in 16 healthy controls and 44 alcoholic patients with biopsy-proved liver disease, namely steatosis without fibrosis (n = 13), perivenular fibrosis (n = 10), septal fibrosis or cirrhosis or both (n = 15) and alcoholic hepatitis (n = 6). In alcoholic patients, serum tissue inhibitor of metalloproteinase values strongly correlated with fibrosis (rs = 0.70, p < 0.001). Compared with values in controls (177 +/- 12 ng/ml), serum tissue inhibitor of metalloproteinase was significantly elevated in perivenular fibrosis (330 +/- 22 ng/ml, p < 0.05), in septal fibrosis, cirrhosis or both (406 +/- 29 ng/ml, p < 0.001) and in alcoholic hepatitis (526 +/- 140 ng/ml, p < 0.001) but not in steatosis (204 +/- 17 ng/ml). In contrast, procollagen III peptides were significantly increased only in the septal fibrosis-cirrhosis group but not in the perivenular fibrosis group. With the threshold defined as the upper value of the steatosis group (resulting in a specificity of 100%), we found that serum tissue inhibitor of metalloproteinase was elevated in 50% of patients with perivenular fibrosis, in 87% of subjects with extensive fibrosis (septal fibrosis, cirrhosis or both) and in 67% of individuals with alcoholic hepatitis. The overall sensitivity of serum tissue inhibitor of metalloproteinase for detecting either perivenular fibrosis or more extensive fibrosis was 71%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tissue inhibitor of metalloproteinase is increased in the serum of precirrhotic and cirrhotic alcoholic patients and can serve as a marker of fibrosis. 818 71

The treatment of alcoholic liver disease at present consists of abstinence from alcohol, bed rest, and dietary intake or administration of adequate amounts of calories and protein. Besides corticosteroids, which have been shown to improve hospital survival in severely ill patients with alcoholic hepatitis and liver transplantation in advanced cirrhosis, no successful specific therapy is available for alcoholic liver disease. Potential new therapeutic approaches include: (1) Treatment with specific dietary supplements such as polyunsaturated lecithin, which in baboons prevented the progression of the early stages of pericentral and interstitial fibrosis to septal fibrosis and cirrhosis; (2) antagonists to cytokines or antibodies to cytokine receptors for cytokines that have been shown to enhance hepatocellular necrosis or fibrosis; (3) substances that block pathways of oxygen radical formation or increase their metabolism or binding to form nonharmful compounds; (4) inhibition of collagen synthesis by proline analogues that increase intracellular collagen degradation or increase in collagen degradation by stimulation of collagenase or by insertion of exogenous DNA encoding amino or carboxyterminal peptides of procollagen into hepatocytes; and (5) stimulation of hepatic regeneration and recovery from alcohol-inducer liver injury.
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PMID:Treatment of alcoholic liver disease. 833 5

Some recent proposals in management of alcoholic liver disease are discussed focusing on early diagnosis and treatment of alcohol abuse itself, alcoholic hepatitis early mortality, clinical meaning of nutritional therapy, serological approach and treatment of hepatic fibrosis, and problems in liver transplantation for end stage alcoholic liver cirrhosis. CAGE or similar systematized brief questionnaires, and desialylated transferrin/total transferrin ratio as serological marker, seems to be interesting contributions to "hidden" alcohol abuse diagnosis and abstinence control while psycho-social support and voluntary incorporation to self-aid groups are the best weapons to reach persistent abstinence. Corticosteroids seems to improve survival in a selected group of patients with severe alcoholic hepatitis, specially in those presenting encephalopathy but free of GI bleeding, decompensated diabetes, active infections, pancreatitis, and other contraindications or adverse effects of these drugs. Relationship between direct toxicity and nutritional deficiencies in pathogenesis of alcoholic liver injury are not clear enough, but malnutrition is generally present in patients requiring hospitalization, and related to clinical severity; oral, enteral or parenteral nutritional supplementation in this order of preference according to patients condition, associated or not with steroid anabolics, are useful in cases with moderate to severe alcoholic hepatitis or decompensated cirrhosis to eliminate the catabolic state, reaching a better nitrogen balance and liver function tests, without special adverse effects. A special role on liver regeneration is discussed. Antioxidants and supernutrients are special "modern" aspects of nutritional therapy in alcoholic liver disease generally related to the MEOS activation in chronic alcoholism, the excessive production of free radicals, and the depletion of glutathione, membrane phospholipids (specially phosphatidycholine), and vitamin A, E, and C. Natural supplements as soybean polyunsaturated lecithin, with high concentration of phosphatidycholine, or oral supplementation with natural metabolic products depleted from the liver of chronic heavy drinkers, such SAMe, have an interesting rationale based on experimental and clinical findings besides availability and costs. Carotenoids and tocopherols supplementation seems to be an useful tool, but are limited in the case of vitamin A because its special toxicity in chronic alcoholism. Serological markers of metabolism of liver connective tissue are clearly involved in fibrogenesis process and other inflammatory connected events; standardization of laboratory methods surely will result in new possibilities of non-invasive valuation of liver injury, evolution and therapeutic response; special histological damage such as sinusoidal "cappilarization" (type i.v. collagen and laminin), endothelial sinusoidal cell function (seric hyaluronate), or collagenase activity (TIMP-1 or tissue inhibitor of metalloproteinases-1) seems to be valuable by these new technologies.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[New suggestions for the management of alcoholic liver diseases]. 852 63

Activation of methionine to S-adenosylmethionine is depressed in alcoholics. Its repletion opposes alcoholic liver cirrhosis in baboons, decreases mortality in cirrhotic patients, and opposes oxidative stress resulting from cytochrome P4502E1 (CYP2E1) induction by alcohol, ketones, and fatty acids. Their excess causes alcoholic and nonalcoholic steatohepatitis. CYP2E1 is also induced in Kupffer cells, promoting their activation and release of inflammatory cytokines, including tumor necrosis factor (TNF)-alpha. The TNF-alpha inhibitor pentoxifylline decreased mortality from alcoholic hepatitis. Polyenylphosphatidylcholine (PPC), an antioxidant phosphatidylcholine mixture extracted from soybeans, 50% of which consists of the highly bioavailable dilinoleoylphosphatidylcholine, restores phospholipids of the damaged membranes and reactivates their enzymes, including phosphatidylethanolamine methyltransferase, needed for phospholipid regeneration. In baboons, PPC prevented cirrhosis by stimulating collagenase and by opposing lipid peroxidation, which produces the fibrogenic hydroxynonenal. PPC was beneficial in patients with alcoholic hepatitis, and it opposed fibrosis in heavy drinkers and decreased aminotransferases in patients with hepatitis C. The antioxidant silymarin also successfully opposed alcoholic cirrhosis in baboons and in some but not all clinical trials; this effect also pertains to a-tocopherol. The anti-inflammatory corticosteroids and colchicine yielded mixed results. Finally, replacing long-chain with medium-chain triglycerides opposed the fatty liver experimentally and clinically.
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PMID:New concepts of the pathogenesis of alcoholic liver disease lead to novel treatments. 1472 Apr 55