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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Viral particles of a neurotropic murine hepatitis virus (JHM) and various substances known to have immunoregulatory effects, including bacterial lipopolysaccharide (LPS) and synthetic adjuvant peptide (muramyl dipeptide) (AP), were tested for their ability to induce Ia antigen expression on Lewis rat astrocytes in vitro. JHM virus, LPS and AP are all capable of inducing Ia molecules on astrocytes, however, in a pattern and kinetics distinct from recombinant rat gamma interferon (gamma-IFN). Whereas gamma-IFN induced Ia expression on astrocytes and all macrophages after 48 h treatment, JHM virus, LPS and AP required 4-7 days for maximal induction of Ia on astrocytes, but had little to no effect on the macrophage population. This indicates that astrocytes are uniquely reactive to components derived from infectious agents and that these components are immunoregulatory with respect to Ia expression on astrocytes. We have also attempted to determine possible mechanisms by which these agents induce astrocyte Ia and show that phorbol myristate acetate and Ca2+ ionophore A23187 have similar effects. These findings suggest that infectious agents may directly stimulate antigen presenting functions of astrocytes in the brain through gamma-IFN-independent mechanisms.
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PMID:Analysis of Ia induction on Lewis rat astrocytes in vitro by virus particles and bacterial adjuvants. 302 54

Peripheral blood lymphocytes (PBLs) isolated from woodchucks chronically infected with the woodchuck hepatitis virus (WHV) carry low levels of nonreplicating WHV DNA. When PBLs from chronic carrier woodchucks were activated in culture with the generalized mitogen lipopolysaccharide (LPS), WHV DNA replication was initiated in cells obtained from one of three animals examined. Intracellular WHV core particles, containing WHV DNA replication intermediates, RNA/DNA hybrid molecules, and an active endogenous DNA polymerase, appeared 3 days after the start of LPS stimulation. After 5 to 7 days of LPS stimulation, WHV DNA-containing particles, which displayed the properties of intact, mature virions, were released into the culture medium. These studies provide evidence for reactivation of a latent WHV infection of circulating lymphoid cells and indicate that the presence of nonreplicating hepadnaviral DNA in lymphoid cells represents a potentially active infection following cellular activation.
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PMID:Mitogen-induced replication of woodchuck hepatitis virus in cultured peripheral blood lymphocytes. 326 87

The role of endotoxin in the pathogenesis of progressive liver disease is receiving increasing attention, but remains controversial. Similarly, although alcoholic hepatitis is now recognized as the transitional link between alcoholic fatty liver and advanced alcoholic liver disease, the aetiology of liver cell necrosis in alcoholic hepatitis is not known. Rats fed a nutritionally adequate liquid alcohol diet according to the formula of Lieber and DeCarli developed fatty livers. Littermates fed an identical diet and challenged with small IV doses (1 microgram/g body weight) of E. coli lipopolysaccharide endotoxin (LPS) developed focal necrotizing hepatitis. Control littermates fed an identical calorie balanced but alcohol free diet and challenged with identical doses of LPS did not develop any liver lesions. The hepatocyte necrosis with associated inflammatory changes induced by LPS in fatty livers has some features of early human alcoholic hepatitis and suggests that progressive alcohol induced damage may be multifactorial in origin.
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PMID:Endotoxin induced hepatic necrosis in rats on an alcohol diet. 330 47

The immune and allergic status of patients with acute viral hepatitides A and B after treatment with prodigiosan, a bacterial lipopolysaccharide preparation, was studied. The drug produced as stimulating effect on cell-mediated and humoral immunity. The development of delayed specific drug sensitization was registered in two-thirds of the patients, which correlated with the regression of clinicobiochemical manifestations of hepatitis.
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PMID:[Indices of immunity and allergy in patients with viral hepatitis treated with prodigiozan]. 336 72

Three new observations bear out the role of endogenous endotoxins in the pathogenesis of murine hepatitis caused by frog virus 3. First, the LD50 of endotoxin is 20 times lower in mice pretreated for 2.5 hr with a sublethal dose of frog virus 3 than in untreated mice. Animals inoculated with one sublethal dose of lipopolysaccharide 2.5 hr after injection of one sublethal dose of virus die, all having developed extensive hepatocellular necrosis. This hypersensitivity varies according to the intensity of virus-induced destruction of Kupffer cells, which are the intrahepatic target of the virus. Second, mortality is significantly lower and the interval between infection and death longer in axenic mice, which are largely protected from portal endotoxemia. Third, the impairment of some biologic activities of endotoxin (through treatment with polymyxin B or indomethacin, for example) protects mice against hepatic damage and death. Likewise, mice rendered tolerant to endotoxins, and C3H/HeJ mice, which are genetically resistant to endotoxins, survive challenge with frog virus 3 and are refractory with regard to hepatocytolysis . These findings suggest that, in hepatitis caused by frog virus 3, endogenous endotoxins are responsible for extensive hepatocytolysis since virus-induced damage to the hepatic reticuloendothelial system prevents their detoxification.
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PMID:Probable role of endogenous endotoxins in hepatocytolysis during murine hepatitis caused by frog virus 3. 672 94

A systemic BCG infection in mice induced multiple small granulomas located mainly in the periportal areas of the liver. Following systemic challenge of such mice with purified protein derivative of tuberculin (PPD), a rapidly developing hepatitis with diffuse intralobular mononuclear cell infiltration was precipitated, accompanied by high levels of aspartate transaminase in peripheral blood, hypoglycemia, focal hepatocyte necrosis, and accumulation of fibrinogen in liver. Bacterial lipopolysaccharide (LPS) also provoked acute hepatic damage both in BCG-infected mice and in mice pretreated with Corynebacterium parvum. PPD was not active in the latter. There were also lymphoid cell destruction and fibrinogen accumulation in the spleen of BCG-PPD-treated mice. Possible involvement of inflammatory and hepatotoxic mediators is suggested, and a T-lymphocyte-macrophage regulatory role in the pathogenesis of hepatitis is discussed.
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PMID:Tuberculin hypersensitivity hepatitis in mice infected with Mycobacterium bovis (BCG). 702 5

It should be apparent from the foregoing that the transgenic mouse model system has contributed substantially to our understanding of many aspects of HBV biology, immunobiology, and pathogenesis in the past several years. We have learned that HBV can replicate within the mouse hepatocyte, as well as other mouse cell types, suggesting that there are probably no strong tissue or species-specific constraints to viral replication once the viral genome enters the cell. However, the failure thus far to detect viral cccDNA in the hepatocyte nucleus in several independently derived transgenic lineages suggests that other, currently undefined, constraints on host range and tissue specificity may also be operative. Thanks to the transgenic mouse model, we now understand the pathophysiological basis for HBsAg filament formation and "ground glass" cell production, and we have learned that at least this viral gene product can be toxic for the hepatocyte, first by compromising its ability to survive the hepatocytopathic effects of lipopolysaccharide and gamma interferon, and eventually by causing it to die in the absence of any obvious exogenous stimulus. In recent studies, it has been shown that preformed nucleocapsid particles do not cross the nuclear membrane, in either direction, at least in the mouse hepatocyte. If this is confirmed, it will have two important implications: first, that nucleocapsid disassembly must occur in the cytoplasm before the nascent viral genome can enter the nucleus; second, that the intranuclear nucleocapsid particles are empty, and therefore serve no currently defined purpose in the viral life cycle. This should stimulate new interest in the analysis of the function of these particles that are a prominent feature of mammalian hepadnavirus infection. The transgenic mouse model has also established definitively that HBV-induced liver disease has an immunologic basis, and that the class I restricted CTL response plays a central role in this process. Additionally, the mouse studies have taught us that when the CTL recognize their target antigen on the hepatocyte they cause them to undergo apoptosis, forming the acidophilic Councilman bodies that are characteristic of viral hepatitis. Further, we have learned that although the CTL initiate the liver disease, they actually contribute more to disease severity indirectly by recruiting antigen nonspecific effector cells into the liver than by directly killing the hepatocytes themselves; and that by releasing gamma interferon when they recognize antigen, the CTL can destroy enough of the liver to cause fulminant hepatitis in mice whose hepatocytes overproduce the large envelope protein and are hypersensitive to the cytopathic effects of this cytokine.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Hepatitis B virus transgenic mice: insights into the virus and the disease. 755 87

Neutralizing anti-tumor necrosis factor alpha (TNF-alpha) antibody treatment of mice infected with the neurotropic JHMV strain of mouse hepatitis virus showed no reduction of either virus-induced encephalomyelitis or central nervous system demyelination. TNF-alpha-positive cells were present in the central nervous system during infection; however, TNF-alpha could not be colocalized with JHMV-infected cells. In vitro, TNF-alpha mRNA rapidly accumulated following JHMV infection; however, no TNF-alpha was secreted because of inhibition of translation. Both live and UV-inactivated virus inhibited TNF-alpha secretion induced by lipopolysaccharide. These data show that TNF-alpha is not secreted from infected cells and indicate that if contributes to either JHMV-induced acute encephalomyelitis nor primary demyelination.
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PMID:Tumor necrosis factor expression during mouse hepatitis virus-induced demyelinating encephalomyelitis. 763 37

The survival rate for acute hepatic failure induced by Propionibacterium acnes and lipopolysaccharide (LPS) was increased when a hot water extract from the flowers of Inula britannica L. subsp. japonica Kitam. was injected into the experimental hepatitis mice, and anti-hepatitis substances could be extracted with CHCl3. The CHCl3 extract from I.britannica was fractionated and anti-hepatitis fractions IB-3-2 and IB-3-3 were obtained. IB-3-3 had the most potent anti-hepatitis activity among the fractions but further purification of the active compound was not achieved because of the low yield. IB-3-2 contained only one substance which was identified to be taraxasteryl acetate by 1H- and 13C-NMR and MS. Taraxasteryl acetate showed potent preventive activity against acute hepatic failure induced by P.acnes and LPS in a dose-dependent manner, however deacetylation and modification of the olefinic bonds significantly decreased the anti-hepatitis activity of taraxasteryl acetate. Taraxasteryl acetate also inhibited the increment of plasma transaminase on acute hepatic failure induced by carbon tetrachloride (CCl4) or D-galactosamine. From a histological study it appeared that degeneration and necrosis, which were observed in the liver from CCl4 mice, were not found in the liver cells from taraxasteryl acetate treated mice. These results indicates that taraxasteryl acetate shows preventive effects on experimental hepatitis caused by either immunologically induced injuries or hepatotoxic chemicals.
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PMID:Preventive effect of taraxasteryl acetate from Inula britannica subsp. japonica on experimental hepatitis in vivo. 1725 90

Gentiopicroside (GPS), a main bitter secoiridoid constituent of roots of Gentiana macrophylla Pall., was tested for therapeutic effects on the two hepatic injury models, the CCl4-induced and lipopolysaccharide (LPS)/bacillus Calmette-Guerin (BCG)-induced hepatitides. An increase in serum level of hepatic aminotransferases (GOT: EC 2.6.1.1. and GPT: EC 2.6.1.2.) induced by a p.o. treatment of CCl4 was suppressed by pretreatment with GPS at 30-60 mg/kg/day for 5 consecutive days. An increase of these enzymes triggered by an i.v. treatment with LPS in mice primed with bacillus Calmette-Guerin (BCG) was also inhibited by GPS pretreatment at the same dose of GPS. In the BCG/LPS model, tumor necrosis factor (TNF), a major inflammatory mediator, was increased in serum with a peak at 90-120 min, followed by an increase of serum transaminase activities. GPS treatment significantly suppressed the increase of TNF in serum at the therapeutic doses, suggesting that GPS protected against hepatitis by inhibiting the production of TNF.
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PMID:Suppression of chemically and immunologically induced hepatic injuries by gentiopicroside in mice. 799 67


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