Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma levels of different amino acids were observed in 10 patients with severe hepatitis, 9 viral in origin and 1 toxic, over the course of the disease. There would appear to be a close relationship between the onset of encephalopathy and the appearance of a particular pattern in plasma amino acid equilibrium, characterised by a significant fall in the molar ratio existing between ramified amino acids (valine, leucine, isoleucine) and aromatic amino acids (phenylalanine and tyrosine). The role of these disturbances in the physiopathology of the encephalopathy and their effects on the synthesis of normal neurotransmitters and the intracerebral accumulation of false neurotransmitters is discussed.
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PMID:[Variation of plasma amino acids in severe hepatitis with encephalopathy 10 cases]. 1 44

A mixture with essential and nonessential amino acids high in branched chain amino acids and low in aromatic amino acids (Fischer solution), and another synthetic mixture of branched chain amino acids containing 3 amino acids associated with the urea cycle (Hep-OU) were infused to control subjects and patients with severe hepatic disease. Alterations in serum aminograms, blood ammonia levels and electroencephalograms following the infusion were studied and compared with those obtained by a commercially available amino acid mixture. Short-term or continuous infusion of a commercially available amino acid solution to cirrhotic patients caused an increase in methionine, phenylalanine and tyrosine and a decrease in branched chain amino acids. These post-infusion results were similar to the patterns seen in hepatic encephalopathy. In cirrhotic patients, infusion of Fischer solution which contains small quantities of methionine and phenylalanine produced an increase in the concentrations of these 2 amino acids, probably because of impaired utilization by the injured liver. No marked alterations in serum aminograms, however, were observed in cirrhotic patients either immediately after, or 3 h after, the end of the Hep-OU infusion. Reduction of methionine, tyrosine and phenylalanine levels and elevation of the molar ratio of (valine + leucine + isoleucine)/(phenylalanine + tyrosine) were significant. The infusion of Hep-OU to patients with liver cirrhosis or subacute hepatitis resulted in clinical and neurological improvements and the restoration of the molar ratio of branched chain amino acids/aromatic amino acids.
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PMID:An approach to nutritional therapy of hepatic encephalopathy by normalization of deranged amino acid patterns in serum. 15 28

Encephalopathic patients with cirrhosis of the liver consistently showed elevated levels of the aromatic amino acids, phenylalanine, tyrosine and free tryptophan as well as methionine in serum, whereas levels of the branched chain amino acids, valine, leucine and isoleucine, were depressed. Comatose patients with fulminant hepatitis had markedly elevated levels of all amino acids, the results being greatly different from those of cirrhotic patients. Molar ratios of (valine + leucine + isoleucine)/(phenylalanine + tyrosine) decreased both in cirrhotics with and without encephalopathy and in cases with fulminant hepatitis. Infusion of a commercially available L-amino acid solution in a cirrhotic patient induced a strikingly abnormal aminogram documented in hepatic encephalopathy. Therefore, effects of branched chain amino acid infusion on the deranged amino acid pattern were primarily studied for the purpose of improvement in hepatic encephalopathy by normalization of serum amino acid patterns. Elevated levels of the aromatic amino acids and methionine could be apparently depressed in a cirrhotic patient by this type of infusion but not in a case of fulminant hepatitis probably because of the poor utilization of these amino acids in severely impaired liver.
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PMID:Serum amino acids in hepatic encephalopathy--effects of branched chain amino acid infusion on serum aminogram. 52 13

Phenylalanine-4-hydroxylase activity was studied in liver tissue, obtained by biopsy from 5 patients with viral hepatitis and from 8 persons without parthological alterations of liver. The enzymatic activity was estimated by formation of 14C-tyrosine in presence and in absence of added cofactor 2-amine-4-hydroxy-6,7-dimethyltetrahydropteridine. Without addition of the cofactor the phenylalanine hydroxylase activity was of the same order of magnitude in liver tissue of the patients and of healthy persons. In presence of the cofactor the enzyme activity in liver of the patients with the hepatitis of moderate severity constituted 44% of the activity found in the control group. The rate of phenylalanine hydroxylation was 0.19 with 10-2 min-1 in patients with hepatitis and 0.5 with 10-2 min-1--in the control group. In severe and moderate forms of viral hepatitis the impairment of phenylalanine metabolism was due to decrease in the activity of phenylalanine-4-hydroxylase in liver tissue.
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PMID:[Phenylalanine-4-hydroxylase activity in the liver in viral hepatitis]. 59 92

Previous work from this laboratory has suggested that the plasma amino acid pattern, known to be deranged in hepatic encephalopathy, may be related causally. In order to test this hypothesis, 23% dextrose and a special amino acid solution whose components were calculated to normalize the plasma amino acid pattern were infused in 11 patients, eight with chronic cirrhosis and acute exacerbation (Group 1) and three patients with fulminant hepatitis (Group 2), in amounts of up to 120 Gm. of protein equivalent per 24 hours. Plasma amino acids were abnormal but different in both groups. In Group 1 (cirrhosis) changes in plasma amino acid pattern including elevated phenylalanine, tyrosine, glutamate, aspartate, and methionine and decreased valine, leucine, and isoleucine. In Group 2 all amino acids were elevated, with the exception of the branched chains which were normal. Hepatic encephalopathy improved in all patients in Group 1 and in one of three patients in Group 2 following the infusion. The ratio (see article) showed an excellent correlation with a grade of encephalopathy. When this ratio, previously 1.0 in the presence of encephalopathy, returned to the normal value near 3.0 to 3.5, encephalopathy improved. An excellent correlation was obtained between the ratio and the grade of encephalopathy and was dose related as well. The results suggest that different amino acid patterns in hepatic encephalopathy of differing etiologies require treatment modalities which may differ for the two types of encephalopathy. Whereas amino acid infusion appears to be a valuable, efficacious way of providing nutrition in treating hepatic encephalopathy in patients with cirrhosis and acute deterioration and coma, other means of therapy such as plasms "laundering" appear to be necessary in patients with fulminant hepatitis.
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PMID:The effect of normalization of plasma amino acids on hepatic encephalopathy in man. 81 29

Plasma amino acids were measured in 18 patients with hepatic encephalopathy on a protein-restricted diet of 20 g or less daily. Plasma aminograms tended to group into two distinct patterns depending on the etiology of the patients' hepatic pathology. Patients with chronic liver disease with superimposed acute insults, i.e., gastrointestinal bleeding, infection, alcoholic hepatitis, had elevated levels of the aromatic amino acids, phenylalanine, tyrosine, and tryptophan, as well as methionine, glutamate, and aspartate, whereas levels of the branched chain amino acids, valine, leucine, and isoleucine, were consistently depressed. Those patients with previously normal livers and acute hepatic necrosis, i.e., "fulminant hepatitis," had grossly elevated levels of all amino acids except the branched chain amino acids, which were normal. Elevations of amino acid levels in this patient group tended to correlate with extent of hepatic necrosis and hence had prognostic significance. Additionally, the different patterns seen in these two groups tend to suggest the indicated therapy as well as predict its efficacy.
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PMID:Plasma amino acid patterns in hepatic encephalopathy of differing etiology. 83 96

Subtoxic doses of endotoxin (salmonella abortus equi lipopolysaccharide, LPS) (5 micrograms/kg i.p.) or tumor necrosis factor alpha (TNF alpha) (15 micrograms/kg i.v.) induced fulminant hepatitis within 8 hr, when mice had been sensitized by a subtoxic dose of D-galactosamine (700 mg/kg i.p.). LPS-treatment led to the release of TNF into the circulation, independently of the presence of D-galactosamine. The TNF-dependent development of hepatitis was accompanied by a severe lymphopenia and neutrophilia as assessed by leukocyte differential count. The total leukocyte count was not significantly affected. Lymphopenia and neutrophilia were induced by LPS or TNF alpha alone; however, the differential count was not influenced by D-galactosamine. A quantity of 260 micrograms/kg phorbol myristate acetate (PMA) i.p. or 5 micrograms/kg platelet activating factor (PAF) i.v. or 3.3 mg/kg N-formyl-methionyl-leucyl-phenylalanine methylester (FMLP) i.v. or 167 mg/kg zymosan i.v. also caused lymphopenia and neutrophilia in mice. However, none of these agents induced the production of systemic TNF and therefore failed to induce hepatitis in D-galactosamine-sensitized mice. In LPS-insensitive C3H/HeJ mice administration of LPS produced neither differential count changes nor hepatitis while both events were observed when TNF alpha was given. This shows that TNF alpha alone gives rise to lymphopenia/neutrophilia as well as hepatitis independent of LPS. When the action of TNF alpha was blocked by anti TNF alpha antiserum pretreatment of LPS-sensitive mice, the animals were protected against LPS-induced hepatitis. However, lymphopenia and neutrophilia still occurred to a similar extent. The involvement of a putative additional mediator of LPS-induced leukocyte alterations was checked. The findings suggest that this mediator, if present, is different from IL-1, IL-2, eicosanoids or superoxide. We conclude from our findings that changes in leukocyte numbers and composition following D-galactosamine LPS or D-galactosamine/TNF alpha administration is an epiphenomenon rather than a causal event of leukocyte stimulation in the process of inducing a fulminant hepatitis in mice.
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PMID:Leukocyte alterations do not account for hepatitis induced by endotoxin or TNF alpha in galactosamine-sensitized mice. 240 85

We have defined three categories of cultured cell lines on the basis of their permissiveness (susceptibility to initial infection) to mouse hepatitis virus (MHV). Fully permissive L-2 cells gave rise to 100-1000-fold higher numbers of infectious centers than did semi-permissive LM, LM-K or C-1300 cells, whereas non-permissive Vero or C-6 cells were refractory to MHV infection. On an infected cell basis, there was no deficiency on the part of semi-permissive cell lines to replicate total viral RNA, viral polypeptides or progeny virions. Two of the semi-permissive cell lines (LM and LM-K) supported persistent MHV infection, while a third (C-1300) succumbed to lytic infection. LM and LM-K cells, but not C-1300 cells showed resistance to MHV-induced membrane fusion, even when placed in contact with fusion-active MHV-infected L-2 cells. The ability of a given cell to undergo fusion did not correlate with membrane lipid characteristics (unsaturated fatty acid and sterol content) which contribute to membrane "fluidity". In order to more closely study the parameters of MHV-induced cell fusion, membranes were prepared from MHV-infected L-2 cells and monitored for their fusogenic potential with permissive L-2 cells, semi-permissive LM cells and non-permissive vero cells. Fusion was only observed with the permissive L-2 cells, and only when exogenous protease (trypsin or chymotrypsin) was added. When the membranes were prepared from 35S-methionine-labeled MHV-infected L-2 cells and subjected to protease treatment, the radiolabeled 180,000 dalton form of the E2-glycoprotein underwent proteolytic cleavage to yield a major product of approximately 90,000 daltons. Both trypsin and chymotrypsin were effective in this proteolytic cleavage and in activating membrane fusion. In a normally permissive, fusogenic infection of MHV in L-2 cells, the protease inhibitors TPCK and ZPCK, but not TLCK, were found to inhibit cell fusion. In MHV-infected L-2 cells, E2 was found almost exclusively as the 180,000 dalton form but turned over rapidly as shown by pulse-chase studies. TPCK and ZPCK but not TLCK inhibited turnover. The results suggest that L-2 cells contain a protease which cleaves at aromatic amino acids such as phenylalanine, and that this protease cleaves the 180,000 dalton form of the E2 to peptide fragments, one or more of which may activate cell fusion.
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PMID:The role of protease-dependent cell membrane fusion in persistent and lytic infections of murine hepatitis virus. 282 27

Changes in biochemical and electroencephalographic parameters were followed over time during the development of acute hepatic encephalopathy (HE) in two different experimental models. In the rat, (sub)acute liver failure was obtained either by ligation of the hepatic artery in previously portacaval-shunted animals or by intraperitoneal injection of a high dose of galactosamine (GALN). The EEG changes were characterized in both models by a significant increase in low-frequency activity of the EEG power density spectra: the so-called 'left shift'. This 'left shift' was significant in liver ischemia after 4-5 h and in GALN hepatitis after about 30 h. The changes in plasma biochemical indices also showed a great similarity in both models. The concentration of all measured plasma amino acids (except histidine and arginine in GALN hepatitis and arginine in liver ischemia), NH3 and ALAT were significantly increased during the development of (sub)acute HE. Correlation of the combined data of electroencephalographic and biochemical indices showed a significant (P less than 0.01) correlation between the 'left shift' and NH3, taurine, threonine, proline, alanine, methionine, cystathionine, phenylalanine, tryptophan, ornithine and histidine. It is concluded that EEG spectral analysis is a useful parameter for following the development of (sub)acute hepatic encephalopathy in relation to biochemical parameters.
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PMID:Correlation between electroencephalographic and biochemical indices in acute hepatic encephalopathy in rats. 359 63

Phenylalanine hydroxylation, tyrosine oxidation, and plasma appearance of phenylalanine and tyrosine were evaluated in a 49-yr-old woman with fulminant non-A, non-B hepatitis and encephalopathy using a continuous intravenous infusion of L-[ring-D5]phenylalanine and L-[U-14C]tyrosine. Despite marked elevations in plasma phenylalanine and tyrosine appearance and normal apparent albumin synthetic rates, phenylalanine clearance and hydroxylation to tyrosine were only 12% and 60%, respectively, of values observed in individuals with normal liver function. Three days after orthotopic liver transplantation, plasma phenylalanine and tyrosine appearances were not markedly changed. Phenylalanine clearance and conversion to tyrosine, however, were restored to normal. In addition, tyrosine oxidation and apparent albumin synthesis were increased. This case report represents the first in vivo demonstration of a selective diminution of enzyme function in an individual with fulminant liver disease. Liver replacement restored aromatic amino acid degradative capacity and increased albumin synthesis.
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PMID:Abnormal phenylalanine hydroxylation and tyrosine oxidation in a patient with acute fulminant liver disease with correction by liver transplantation. 392 94


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