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)

One of the most sensitive and specific signs of the galactosamine effect upon the rat liver cell is the appearance of PAS-positive and diastase-resistant granules within the cytoplasm of hepatocytes. Light-microscopic, histochemical, biochemical, and electron-microscopic findings reveal that the appearance of these ADB (= atypical dense bodies) depends upon a working glycogen metabolism at the time of GalN treatment. The ADB are composed of particles resembling, due to shape and size, ribosomes and beta particles of glycogen. Most of them are surrounded by the rER, but they are never enclosed by a limiting membrane. Due to sequential changes they can be generally classified into three types; the early, the intermediate, and the late type. In seven experiments it can be shown, that the appearance of the ADB depends upon the time and dosage after GalN treatment. They occur even if an additional treatment with galactose or uridine prevents the liver from the features of a hepatitis, as also shown in the livers of newborn animals up to 3 weeks of age. The histochemical response against various glucosidases, hexosaminidases, pronase, and RNAse as well as against various fixatives indicates that ADB are composed of, at least, two different constituents, the former RNAse-sensitive and visible with routine light-microscopic staining procedures, the latter RNA-resistant, PAS-positive, and invisible after staining with H & E or toluidine blue. The latter is diastase-resistant, suggesting that this portion of ADB does not represent the usual glycoproteins but some abnormal metabolite of glycogen. The ADB can be detected with maximal accumulation in the cytoplasm of hepatocytes at that time when the glycogen content determined in the liver homogenate by biochemical methods is greatly reduced.
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PMID:The appearance and degradation of specific hepatocellular cytoplasmic inclusion bodies in rat liver due to D-galactosamine. I. The relation between the amount of liver glycogen and the appearance of the atypical dense bodies in the liver cell. 18 85

Two strains of leukocyte hepatitis virus (LHV) which had undergone 13 and 16 passages, respectively, in phytohemagglutinin-stimulated cultures of leukocytes from normal donors were studied in experiments with labelled precursors (3H-uridine and 14C-amino acids). The buoyant density of the virus (1,26 g/ml) and sedimentation constant of RNA (46 S) were determined. LHV was shown to be capable of reproduction in human kidney cell culture. The immunofluorescence test could be used with labeled convalescent sera for examinations of blood smears from patients for diagnosis of hepatitis A in foci of infection. In these tests, fluorescence was detected in the cytoplasm of lymphocytes and granulocytes but not in the nucleus. The immunofluorescence test with convalescent sera was successfully used for the examinations of smears of cultures of PHA-stimulated leukocytes of normal donors infected with LHV in order to prove the specificity of this virus in hepatitis A.
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PMID:[Further study of the leukocyte virus isolated in hepatitis A]. 21 10

The effect of cytidine and uridine on the reparative processes in the rat liver in experimental hepatitis induced by CCl was studied. Combined administration of uridine or cytidine with CCl4 during 7 days does not prevent the liver affection. The subsequent nucleoside treatment (up to 15 and 20 days) accelerates to a different degree the reparative processes after CCl4 withdrawal. Thus, cytidine provokes marked hypertrophy of regenerated hepatocytes accompanied by proliferation of the mesenchymal elements, not followed, however, by recovery of the conjugative and excretory liver functions. Uridine, in contrast to cytidine, promotes more rapid normalization of these functions though the organ structure regeneration is not complete.
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PMID:[Effect of cytidine and uridine on liver regeneration in rats poisoned by carbon tetrachloride]. 51 7

1. An injection of D-galactosamine (GalN) into mice together with a lipopolysaccharide (LPS or endotoxin), interleukin-1 (IL-1) or tumour necrosis factor (TNF), sensitized the mice and induced fulminant hepatitis with severe congestion resulting in rapid death. Since LPS and these cytokines induce ornithine decarboxylase (ODC) and histidine decarboxylase (HDC) in the liver and spleen of mice, the effects of GalN on the induction of ODC and HDC in these organs were examined. 2. The induction of ODC by LPS, IL-1 or TNF was suppressed by GalN in the liver, and this suppression preceded the hepatic congestion. There was good agreement between the degree of hepatic congestion and the suppression of ODC induction by various amounts of GalN. The induction of ODC in the spleen was suppressed only at the highest dose of GalN examined. 3. GalN is known to deplete uridine 5'-triphosphate (UTP), resulting in the suppression of RNA and protein synthesis. An injection of uridine, the precursor of UTP, diminished the GalN-induced suppression of ODC induction by LPS and prevented the hepatic congestion and death. 4. LPS-pretreatment before injection of LPS plus GalN prevented the suppression of ODC activity and prevented the hepatic congestion and death. 5. An injection of putrescine, the product of ODC, prolonged survival time and delayed the development of hepatic congestion. However, injection of an ODC inhibitor into the mice given LPS did not produce hepatic congestion. 6. The induction of HDC in the liver by LPS, IL-1 or TNF was not suppressed by GalN and, at high doses, the response to LPS was enhanced. An inhibitor of HDC neither prevented the hepatic congestion nor enhanced the protective effect of putrescine.7. Although GalN in combination with IL-la induced a markedly higher HDC activity than was observed when it was combined with TNFa, and suppressed the induction of ODC, the former combination at the doses used did not produce hepatic congestion or death. However, the sensitization to TNFa by GalN was markedly potentiated by IL-la.8. These results suggest that suppression of the induction of ODC by GalN may be one cause of the sensitization to LPS, IL-1 or TNF, and that the induction of HDC, i.e. histamine formation, may not be involved in this sensitization.9. These results are consistent with the hypothesis that both IL-1 and TNF are involved in the sensitization to LPS.
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PMID:Ornithine and histidine decarboxylase activities in mice sensitized to endotoxin, interleukin-1 or tumour necrosis factor by D-galactosamine. 147 81

Both genomic and subgenomic replicative intermediates (RIs) and replicative-form (RF) structures were found in 17CL1 mouse cells that had been infected with the A59 strain of mouse hepatitis virus (MHV), a prototypic coronavirus. Seven species of RNase-resistant RF RNAs, whose sizes were consistent with the fact that each was derived from an RI that was engaged in the synthesis of one of the seven MHV positive-strand RNAs, were produced by treatment with RNase A. Because the radiolabeling of the seven RF RNAs was proportional to that of the corresponding seven positive-strand RNAs, the relative rate of synthesis of each of the MHV positive-strand RNAs may be controlled by the relative number of each of the size classes of RIs that are produced. In contrast to alphavirus, which produced its subgenome-length RF RNAs from genome-length RIs, MHV RF RNAs were derived from genome- and subgenome-length RIs. Only the three largest MHV RF RNAs (RFI, RFII, and RFIII) were derived from the RIs that migrated slowest on agarose gels. The four smallest RF RNAs (RFIV, RFV, RFVI, and RFVII) were derived from RIs that migrated in a broad region of the gel that extended from the position of 28S rRNA to the position of the viral single-stranded MHV mRNA-3. Because all seven RIs were labeled during very short pulses with [3H]uridine, we concluded that the subgenome-length RIs are transcriptionally active. These findings, with the recent report of the presence of subgenome-length negative-strand RNAs in cells infected with porcine transmissible gastroenteritis virus (P. B. Sethna, S.-L. Hung, and D. A. Brian, Proc. Natl. Acad. Sci. USA 86: 5626-5630, 1989), strongly suggest that coronaviruses utilize a novel replication strategy that employs the synthesis of subgenomic negative strands to produce subgenomic mRNAs.
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PMID:Coronavirus transcription: subgenomic mouse hepatitis virus replicative intermediates function in RNA synthesis. 215 91

Intravenous injection of murine recombinant tumor necrosis factor alpha(TNF-alpha) to male NMRI albino mice in doses greater than 4 micrograms/kg (specific activity 4 x 10(7) U/mg) resulted in a fulminant hepatitis when animals had been sensitized 1 hr before by intraperitoneal administration of 700 mg/kg galactosamine. Liver injury was assessed by measurement of serum transaminases as well as sorbitol dehydrogenase activity 8 hr after administration of TNF-alpha. Pretreatment with either galactosamine or 40 micrograms/kg TNF-alpha alone did not cause hepatitis. Pretreatment of galactosamine/TNF-alpha-injured mice with 800 mg/kg uridine or with 6 mg/kg calmidazolium fully protected the animals, while administration of either verapamil or nifedipine (100 mg/kg, respectively) had no significant effect. The following inhibitors of generation or action of leukotriene D4, which were previously shown to block galactosamine/endotoxin-induced hepatitis in mice, failed to protect against galactosamine/TNF-alpha-induced intoxication: 200 micrograms/kg dexamethasone, 174 mg/kg BW 755 C or 13 x 10 mg/kg FPL 55712. In addition, unlike in the galactosamine/endotoxin model no prevention was achieved by pretreatment of galactosamine/TNF-alpha-injured animals with the following substances blocking the development of an ischemia/reperfusion syndrome: 2 x 100 mg/kg allopurinol, 3.3 x 10(4) U/kg superoxide dismutase, 10(6) U/kg catalase or 10 micrograms/kg iloprost. We conclude from our results that tumor necrosis factor alpha is likely to act as a final mediator of endotoxin action in a sequence of events which includes formation of leukotriene D4 and reactive oxygen species.
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PMID:Tumor necrosis factor is a terminal mediator in galactosamine/endotoxin-induced hepatitis in mice. 246 8

The metabolism of chemical carcinogens was investigated in liver preparations from 28 captive woodchucks (Marmota monax). Of these, 23 were naturally infected with the woodchuck hepatitis virus (WHV), and eight also had primary hepatocellular carcinoma (PHC). Twenty-nine parameters were investigated in liver subcellular fractions, including cross-reactivity with HBsAg, and biochemical parameters, such as gamma-glutamyl transpeptidase, cytochrome P-450 and microsomal monooxygenases (aryl hydrocarbon hydroxylase, ethoxycoumarin and ethoxyresorufin deethylases, aminopyrine and dimethylnitrosamine demethylases, and testosterone 7 alpha-, 16 alpha- and 6 beta-hydroxylases), uridine 5'-diphosphoglucuronosyl transferase, GSH and related enzymes (peroxidase, reductase and S-transferase), as well as other cytosolic enzyme activities (glucose 6-phosphate and 6-phosphogluconate dehydrogenases, NADPH- and NADH-dependent diaphorases, and DT diaphorase). In addition, liver preparations were used in order to quantify the metabolic activation into bacterial mutagens of five procarcinogens (aflatoxin B1, the pyrolysis products Trp-P-2 and MeIQ, 2-aminofluorene and dimethylnitrosamine) and the decrease of potency of three direct-acting mutagens (sodium dichromate, ICR 191 and 4-nitroquinoline 1-oxide). WHV infection produced a significant stimulation of carcinogen metabolism, as shown by the simultaneous change in detoxification parameters (GSH depletion) and activation indices (enhancement of microsomal monooxygenases and of procarcinogen activation into mutagenic metabolites). There were no significant differences between WHV-positive samples from animals without PHC and the noncancerous tissue of PHC-bearing animals, whereas a decrease of both activation and detoxification indices was recorded in the tumorous tissue. There was a considerable interindividual variability among WHV carriers, which was tentatively ascribed to genetic factors. Pregnancy was the only known factor influencing the results in WHV carriers. However, even by excluding pregnant animals, the effects on carcinogen metabolism produced by WHV infection were still statistically significant. These results, together with previous data obtained in humans, revealed that metabolic factors may play a role in the synergism between viral hepatitis and chemical hepatocarcinogens in the etiopathogenesis of PHC.
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PMID:Enhanced metabolic activation of chemical hepatocarcinogens in woodchucks infected with hepatitis B virus. 272 Sep 3

The temporal sequence of coronavirus plus-strand and minus-strand RNA synthesis was determined in 17CL1 cells infected with the A59 strain of mouse hepatitis virus (MHV). MHV-induced fusion was prevented by keeping the pH of the medium below pH 6.8. This had no effect on the MHV replication cycle, but gave 5- to 10-fold-greater titers of infectious virus and delayed the detachment of cells from the monolayer which permitted viral RNA synthesis to be studied conveniently until at least 10 h postinfection. Seven species of poly(A)-containing viral RNAs were synthesized at early and late times after infection, in nonequal but constant ratios. MHV minus-strand RNA synthesis was first detected at about 3 h after infection and was found exclusively in the viral replicative intermediates and was not detected in 60S single-stranded form in infected cells. Early in the replication cycle, from 45 to 65% of the [3H]uridine pulse-labeled RF core of purified MHV replicative intermediates was in minus-strand RNA. The rate of minus-strand synthesis peaked at 5 to 6 h postinfection and then declined to about 20% of the maximum rate. The addition of cycloheximide before 3 h postinfection prevented viral RNA synthesis, whereas the addition of cycloheximide after viral RNA synthesis had begun resulted in the inhibition of viral RNA synthesis. The synthesis of both genome and subgenomic mRNAs and of viral minus strands required continued protein synthesis, and minus-strand RNA synthesis was three- to fourfold more sensitive to inhibition by cycloheximide than was plus-strand synthesis.
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PMID:Coronavirus minus-strand RNA synthesis and effect of cycloheximide on coronavirus RNA synthesis. 286 30

The biochemical basis of the hepatitis-like liver injury produced by D(+)-galactosamine in rats is well-established and is linked to depletion of uridine nucleotides within parenchymal cells. However, the prominent inflammatory response that accompanies this lesion in vivo has been largely overlooked as a component of the hepatic damage. This study examines the cellular components of the inflammatory infiltrate of galactosamine-induced liver injury over time using histochemical and ultrastructural techniques. By 12 h after toxin administration, the infiltrate consisted largely of neutrophils and recently-mobilized monocytes. By 24 to 48 h after the toxin, when hepatocellular necrosis was maximal, few neutrophils were found in the infiltrate. At these times, the infiltrate consisted almost exclusively of large phagocytic cells, histochemically and morphologically consistent with active tissue macrophages apparently derived from circulating monocytes. The extent of the inflammatory response to this experimental hepatotoxin suggests that effects on the generation and development of the inflammatory response should be considered for treatments reported to alter the intrinsic hepatotoxicity of galactosamine.
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PMID:An ultrastructural and histochemical study of the prominent inflammatory response in D(+)-galactosamine hepatotoxicity. 295 87

The effects of wuweizisu C, a lignan component of schizandra fruits, on liver injuries induced by carbon tetrachloride (CCl4), d-galactosamine and dl-ethionine were investigated by means of serum-biochemical and histopathological examinations in rats. Pretreatment or combined administration of wuweizisu C dose-dependently reduced the elevation of serum transaminase activity and histological changes such as fatty degeneration, cell necrosis, inflammatory cell infiltration, etc., which were caused by the single administration of 1 ml/kg, p.o., or the repeated administration of 0.2 ml/kg, s.c., daily for 4 days of CCl4, respectively. The effects of wuweizisu C on the liver injuries induced by a low dose (200 mg/kg, i.p.) and a high dose (400 mg/kg, i.p.) of d-galactosamine were compared with those of uridine. Wuweizisu C significantly lowered the rise of serum transaminase activity after the administration of a low dose of d-galactosamine in the serum-biochemical analysis. A tendency was also shown to inhibit cell necrosis and inflammatory cell infiltration caused by both doses of d-galactosamine in the histopathological examination. On the other hand, uridine markedly repaired the serum-biochemical and histopathological changes after the administrations of both doses of d-galactosamine. Also wuweizisu C cured the liver injury by the repeated administration of 150 mg/kg, i.p., daily for 4 days of d-galactosamine. After the repeated administration of 250 mg/kg, s.c., daily for 4 days of ethionine, liver cell atrophy, diffuse fatty degeneration and decrease of serum triglyceride were observed, but not cell necrosis. Wuweizisu C dose-dependently inhibited fatty degeneration and decrease of serum triglyceride. These findings suggest that wuweizisu C can be protective and/or therapeutic on hepatocellular phenomena such as cell necrosis, fatty degeneration, inflammatory cell infiltration, etc., in human hepatitis.
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PMID:[Pharmacological studies on schizandra fruits. III. Effects of wuweizisu C, a lignan component of schizandra fruits, on experimental liver injuries in rats]. 298 31


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