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 tyrosine were assayed in the fasting state and after oral administration of either tyrosine (tyrosine tolerance test) or phenylalanine (phenlyalanine conversion test) in normal subjects and in patients with hepatitis, biliary obstruction, or cirrhosis. Fasting tyrosine levels tended to be slightly increased in patients with hepatitis and biliary obstruction and markedly increased in patients with cirrhosis. Tyrosine tolerance tests in patients with cirrhosis were characterized by larger than normal increments in tyrosine levels and by delayed returns toward fasting levels. The results of phenylalanine conversion tests were abnormal in approximately one-half of patients with either hepatitis or biliary obstruction and four-fifths of patients with cirrhosis. Abnormalities were characterized by elevated fasting plasma tyrosine levels, or small and delayed increments in tyrosine levels, or both. Abnormal phenylalanine conversion test results in patients with cirrhosis did not correlate closely with any clinical feature of cirrhosis or with the results of any standard liver function test; there was positive correlation only with abnormal ammonia tolerance, a test of portalsystemic shunting. Tests of tyrosine metabolism do not appear to be useful for routine clinical assessment of liver function. Tyrosine tolerance tests and phenylalanine conversion tests done for purposes of diagnosis of other diseases may yield misleading results in patients with liver disease.
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PMID:Tyrosine metabolism in patients with liver disease. 607 4

Permeability of the blood brain barrier in relation to the development of hepatic encephalopathy was investigated in two animal models of acute hepatic failure, in one of which there was the potential for recovery (D-galactosamine-induced hepatitis). In both this and the hepatic devascularization model, there was an approximate 3-fold increase in the passive permeability of the blood brain barrier to inulin and sucrose. Transport of amino acids was also significantly affected, with approximate 30% increases in the brain uptake of phenylalanine, tyrosine and arginine and a 65% increase in uptake of leucine. These changes are attributed to the action of circulating toxic substances, some of which increase blood brain barrier permeability in normal animals.
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PMID:Experimental studies of blood brain barrier permeability in acute hepatic failure. 637 48

Serum amino acid patterns in patients with different types of hepatic encephalopathy were investigated. Marked elevations in most of serum amino acids observed in untreated patients with acute type of fulminant hepatitis were not remarkable in the patients who have already treated; particularly branched chain amino acids (BCAA), phenylalanine and tyrosine were much lower in the latter group. However, elevation of serum methionine levels and lower ratio of BCAA/(phenylalanine + tyrosine) were similarly observed in both groups. In encephalopathic patients with decompensated cirrhosis, many amino acids such as phenylalanine, tyrosine and methionine were elevated with a slight depressed levels of serum BCAA. Highly significant decrease in serum BCAA levels and no elevation of phenylalanine and methionine with a minimal increase of tyrosine were observed in patients with chronic type of hepatic encephalopathy; other amino acids except for glutamine and arginine were much lower as compared to those in decompensated cirrhotics and even to the control values.
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PMID:Characteristics change in serum amino acid levels in different types of hepatic encephalopathy. 711 80

A 10 year old boy, in grade IV hepatic coma, was treated by combination of XAD-4 resin hemoperfusion (HP), activated charcoal HP (Adsorba 300C, Gambro), exchange transfusion by up to 12.0 liters of fresh whole blood, and regular dialysis. Serum free amino acids' values were consecutively assessed during 4 days of treatment. The liver was 490 gr in weight at autopsy and histologic examination revealed cellular necrosis compatible with fulminant hepatitis. Pre-treatment values of alanine, lysine, proline, phenylalanine, arginine, threonine, tyrosine and methionine were increased by 2 to 38 times of normal control, while those of cystine, glutamic acid, serine and glycine were minimally increased up to 1.7 times. Histidine, isoleucine, leucine and valine, on the other hand, were decreased by 20 to 30% and aspartic acid was the lowest at 14% of normal control. The effect of XAD-4 resin HP and exchange transfusion was rather non-specific by decreasing the total amount of amino acids. The molar ratios of branched chain amino acids vs. aromatic amino acids or essential amino were elevated by activated charcoal HP, but, did not reach to normal range.
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PMID:[Variation of serum free amino acids in fulminant hepatitis treated with hepatic assists (author's transl)]. 740 29

Infection with hepadnaviruses and exposure to dietary aflatoxin are considered major risk factors in the development of hepatocellular carcinoma (HCC) both in humans and in animals. Recently, a broad range of mutations in the p53 tumor suppressor gene has been reported in human HCCs, predominantly from hepatitis B virus carriers in areas with either high or low levels of exposure to dietary aflatoxin. To determine whether p53 mutations are common to HCCs of hosts infected with related hepadnaviruses with and without treatment with aflatoxin, we studied the occurrence of mutations in the p53 gene in HCCs of ground squirrels and woodchucks with history of infection with ground squirrel hepatitis virus (GSHV) and woodchuck hepatitis virus, respectively. Sequencing of wild type p53 genes from ground squirrels and woodchucks revealed remarkable homology between the two species with only a few amino acid differences in exons 4, 8, and 9. Using direct polymerase chain reaction sequencing, we analyzed the state of the p53 gene (exons 4-9) in 20 HCCs from ground squirrels (2 uninfected, 7 with past, and 11 with ongoing infection with GSHV) and in 11 HCCs from woodchucks persistently infected with woodchuck hepatitis virus. Five GSHV carrier and two uninfected ground squirrels received i.p. administration of aflatoxin B1. We detected only one mutation in the p53 gene of the tested animals. This mutation was located in codon 176 of exon 5 in the HCC of a GSHV-positive ground squirrel treated with aflatoxin. Mutation was caused by a G to T transversion in the second position of the codon, resulting in the replacement of cysteine with phenylalanine, and was accompanied by a tumor-specific loss of heterozygosity. p53 allelic amino acid variation with sequences coding for aspartic acid or asparagine was present in codon 61 in the variable region of exon 4 in both HCCs and nonneoplastic tissues of ground squirrels. In view of the considerably lower apparent rate of mutations in comparison to human HCCs, we suggest a less important role for aflatoxin in the induction of p53 mutations in HCCs of ground squirrels. Alternatively, etiological factors other than p53 mutations may be of greater significance in the development of HCC in ground squirrels and woodchucks.
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PMID:State of the p53 gene in hepatocellular carcinomas of ground squirrels and woodchucks with past and ongoing infection with hepadnaviruses. 792 76

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

In this study, a previously not documented variant of hepatitis B virus was described in Chinese patients with fulminant hepatitis. The entire precore/core region amplified from samples was cloned into a bacterial vector and sequenced by dideoxy chain termination reaction. Double amino acid substitutions were seen in the precore region in the isolates: one from glycine to aspartic acid at codon 29 previously reported; the other substitution of phenylalanine for valine at codon 17 in the cleavage site of hepatitis B virus. Loss of hepatitis B virus e antigen in these patients with fulminant hepatitis might therefore be due to the mutation in the cleavage site, rather than the emergence of a stop codon in the precore region of hepatitis B virus. Accumulation of hepatitis B e antigen precursor within the hepatocytes might account for the fulminant hepatitis exacerbation.
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PMID:[Genetic variation in the cleavage site of the precore region of hepatitis B virus in Chinese patients with fulminant hepatitis]. 873 42

The capsid particle of hepadnaviruses is assembled from its dimer precursors. However, the mechanism of the protein-protein interaction is still poorly understood. A small region in the capsid protein of woodchuck hepatitis virus (WHV) contains four hydrophobic residues, including leucine 101, leucine 108, valine 115, and phenylalanine 122, that are conserved and spaced every seventh residue in the primary sequence to form a hydrophobic heptad repeat (hhr). A hydrophobic force often plays an important role in the interaction of proteins. Therefore, to investigate the role of this region in capsid assembly, we individually changed the codons specifying these four hydrophobic amino acids to codons specifying alanine or proline. In addition, we examined the in vivo infectivity of a WHV genome bearing a naturally occurring single amino acid change (histidine 104-->proline) in the hhr region. The phenotype of each altered genome was determined in both eukaryotic and prokaryotic systems by a capsid protein assay and electron microscopic examination. We show that replacement of any one of the four hydrophobic residues with alanine did not prevent capsid assembly. However, assembled capsid particles were not detected if combinations of any two of the four residues were substituted with alanines or if the spacing of these four hydrophobic residues was changed. An individual introduction of a proline (which dramatically changes the secondary structure of proteins) into different positions of this small region also abolished capsid assembly in vitro or viral replication in vivo. These results suggested that the hhr region of the core protein of WHV was critical for capsid assembly.
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PMID:A hydrophobic heptad repeat of the core protein of woodchuck hepatitis virus is required for capsid assembly. 879 54

GB virus B (GBV-B) is a recently discovered virus responsible for hepatitis in tamarins (Saguinus species). GBV-B belongs to the Flaviviridae family and is closely related to the human pathogen hepatitis C virus (HCV). Nonstructural protein 3 (NS3) of HCV has been shown to encompass a serine protease domain required for viral maturation. GBV-B and HCV share only about 30% of the amino acid sequence within the NS3 protease domain. The catalytic triad is conserved, and the residue Phe-154, presumed to be a crucial amino acid for determining the S1 specificity pocket of the HCV NS3 protease, is also conserved. We have expressed a synthetic gene encoding the GBV-B NS3 protease domain in Escherichia coli and have characterized the purified recombinant protein for its activity on HCV substrates. We have shown that the NS3 region of the GBV-B genome actually encodes a serine protease that, despite the low sequence homology, shares substrate specificity with the HCV NS3 protease.
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PMID:GB virus B and hepatitis C virus NS3 serine proteases share substrate specificity. 918 62

We previously demonstrated by site-directed mutagenesis analysis that the amino acid residues at positions 62 and 214 to 216 in the N-terminal region of mouse hepatitis virus (MHV) spike (S) protein are important for receptor-binding activity (H. Suzuki and F. Taguchi, J. Virol. 70:2632-2636, 1996). To further identify the residues responsible for the activity, we isolated the mutant viruses that were not neutralized with the soluble form of MHV receptor proteins, since such mutants were expected to have mutations in amino acids responsible for receptor-binding activity. Five soluble-receptor-resistant (srr) mutants isolated had mutations in a single amino acid at three different positions: one was at position 65 (Leu to His) (srr11) in the S1 subunit and three were at position 1114 (Leu to Phe) (srr3, srr4, and srr7) and one was at position 1163 (Cys to Phe) (srr18) in the S2 subunit. The receptor-binding activity examined by a virus overlay protein blot assay and by a coimmunoprecipitation assay showed that srr11 S protein had extremely reduced binding activity, while the srr7 and srr18 proteins had binding activity similar to that of wild-type cl-2 protein. However, when cell surface receptors were used for the binding assay, all srr mutants showed activity similar to that of the wild type or only slightly reduced activity. These results, together with our previous observations, suggest that amino acids located at positions 62 to 65 of S1, a region conserved among the MHV strains examined, are important for receptor-binding activity. We also discuss the mechanism by which srr mutants with a mutation in S2 showed high resistance to neutralization by a soluble receptor, despite their sufficient level of binding to soluble receptors.
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PMID:Identification of spike protein residues of murine coronavirus responsible for receptor-binding activity by use of soluble receptor-resistant mutants. 937 59


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