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

The neurotropic JHM strain of mouse hepatitis virus (MHV) causes acute encephalitis and chronic demyelinating encephalomyelitis in rodents. Previous results indicated that CD8 T cells infiltrating the central nervous system (CNS) were largely antigen specific in both diseases. Herein we show that by 7 days postinoculation, nearly 30% of the CD4 T cells in the acutely infected CNS were MHV specific by using intracellular gamma interferon (IFN-gamma) staining assays. In mice with chronic demyelination, 10 to 15% of the CD4 T cells secreted IFN-gamma in response to MHV-specific peptides. Thus, these results show that infection of the CNS is characterized by a large influx of CD4 T cells specific for MHV and that these cells remain functional, as measured by cytokine secretion, in mice with chronic demyelination.
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PMID:High-magnitude, virus-specific CD4 T-cell response in the central nervous system of coronavirus-infected mice. 1122 33

Caspases are key mediators in liver inflammation and apoptosis. In the present study we provide evidence that a nitric oxide (NO) derivative of ursodeoxycholic acid (UDCA), NCX-1000 ([2-(acetyloxy)benzoic acid 3-(nitrooxymethyl)phenyl ester]), protects against liver damage in murine models of autoimmune hepatitis induced by i.v. injection of Con A or a Fas agonistic antibody, Jo2. Con A administration causes CD4(+) T lymphocytes to accumulate in the liver and up-regulates FasL expression, resulting in FasL-mediated cytotoxicity. Cotreating mice with NCX-1000, but not with UDCA, protected against liver damage induced by Con A and Jo2, inhibited IL-1beta, IL-18, and IFN-gamma release and caspase 3, 8, and 9 activation. Studies on HepG2 cells demonstrated that NCX-1000, but not UDCA, directly prevented multiple caspase activation induced by Jo2. Incubating HepG2 cells with NCX-1000 resulted in intracellular NO formation and a DTT-reversible inhibition of proapoptotic caspases, suggesting that cysteine S-nitrosylation was the main mechanism responsible for caspase inhibition. Collectively, these data suggest that NCX-1000 protects against T helper 1-mediated liver injury by inhibiting both the proapoptotic and the proinflammatory branches of the caspase superfamily.
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PMID:An NO derivative of ursodeoxycholic acid protects against Fas-mediated liver injury by inhibiting caspase activity. 1122 94

Most of the information available on stavudine (d4T) comes from studies in patients with advanced human immunodeficiency virus (HIV) disease to whom stavudine was administered as monotherapy. Herein, we summarize the results of adding 40 mg stavudine twice daily to previous therapies in patients with mild to advanced immunological disease (mean CD4 T cell count 178 cells/mm3; range 6-480 cells/mm3). In an intention-to-treat, prospective, open trial, 64 patients (84.4% men; mean age 35.2 years) were analysed. Their average time on previous antiretroviral therapy was 19.8 months (range 6-52). Plasma HIV RNA load fell by a mean of 0.64 and 0.74 log at 1 and 3 months, respectively, after the start of stavudine therapy (P <0.001 Sign rank test). The CD4 cell count increased by a mean of 25.1 cells/mm3 in the third month (P = 0.002 Sign rank test). Antiviral activity was independent of the CD4 cell count at baseline, but more pronounced declines in viral load were seen in patients with shorter periods of previous antiretroviral therapy and in those in whom stavudine was combined with didanosine or lamivudine rather than zidovudine. Ten (15.6%) patients discontinued the drug during the first 6 months of treatment because of the development of toxicity (neuropathy in six cases, hepatitis in two, oedema in one and rash in another); all but one of them had CD4 counts < 200 cells/mm3. Another two patients stopped treatment voluntarily. The remaining 52 patients tolerated the drug well for the first 6 months and had a high level of compliance with treatment. In conclusion, stavudine is generally well tolerated and has significant antiretroviral activity when it is administered to patients with extensive previous treatment with multiple reverse transcriptase (RT) inhibitors. It should be expected that the short-term favourable effects of stavudine on laboratory markers will further translate into a reduced progression of disease and improved survival.
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PMID:Short-term efficacy and safety of stavudine in pretreated HIV-infected patients. 1132 73

Autoimmune hepatitis (AIH) in humans arises spontaneously in genetically susceptible individuals and is associated with the presence of Th1 cells in the liver. The understanding of AIH has advanced more slowly than that of other organ-specific autoimmune diseases, however, largely because of the lack of an appropriate animal model. We now describe a new mouse model characterized by spontaneous development of necroinflammatory hepatitis that is restricted by genetic background. Mice deficient in the immunomodulatory cytokine TGF-beta1 were extensively back-bred to the BALB/c background. The BALB/c background dramatically modified the phenotype of TGF-beta1(-/-) mice: specifically, BALB/c-TGF-beta1(-/-) mice developed a lethal necroinflammatory hepatitis that was not observed in TGF-beta1(-/-) mice on a different genetic background. BALB/c background TGF-beta1(-/-) livers contained large numbers of activated CD4(+) T cells that produced large quantities of IFN-gamma, but little IL-4, identifying them as Th1 cells. BALB/c background TGF-beta1(-/-)/IFN-gamma(-/-) double knockout mice, generated by cross-breeding, did not develop necroinflammatory hepatitis, demonstrating that IFN-gamma is mechanistically required for its pathogenesis. This represents the first murine model of hepatitis that develops spontaneously, is restricted by genetic background, and is dependent upon the Th1 cytokine IFN-gamma, and that thus recapitulates these important aspects of AIH.
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PMID:Genetic regulation of autoimmune disease: BALB/c background TGF-beta 1-deficient mice develop necroinflammatory IFN-gamma-dependent hepatitis. 1134 67

Merck & Co. has announced an expanded-access program to make Crixivan (generic name, indinavir sulfate), its experimental protease inhibitor, available to persons with a CD4 (T-helper) count of 50 or below. The new program will allow 1,100 people in the U.S. and 650 people from other countries to obtain the drug, formerly known as MK-639 and L-735,524. U.S. participants must register by August 11, 1995; those registered after that date will be placed on a waiting list. To be eligible, participants must have a CD4 count less than 50, be at least 18 years old, cannot have hepatitis, and cannot be pregnant or breastfeeding. Required laboratory tests, paid for by Merck, will fulfill additional entry criteria. Patients are allowed to combine the Crixivan with most other drugs. Patients in the open-label study will be treated by their own doctors.
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PMID:Merck protease inhibitor available to persons with CD4 count 50 or less--must register by August 11. 1136 18

Inoculation of mice with most neurotropic strains of the coronavirus mouse hepatitis virus results in an immune response-mediated demyelinating disease that serves as an excellent animal model for the human disease multiple sclerosis. Recent work has shown that either virus-specific CD4(+) or CD8(+) T cells are able to mediate demyelination and also that the antibody response is crucial for clearing infectious virus. Another exciting advance is the development of recombinant coronaviruses, which, for the first time, will allow genetic manipulation of the entire viral genome.
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PMID:Mouse hepatitis virus. 1149 12

Apoptosis is a physiological process critical for tissue homeostasis. It is essential for the regulation of immune responses. A series of molecules transduce apoptoic signals and induce the characteristic morphological appearances of apoptotic cells. Infectious diseases modulate apoptosis and this contributes to disease pathogenesis. Infection with HIV results in enhanced levels of CD4 T-lymphocyte apoptosis in both directly infected cells and in uninfected bystander cells. A variety of HIV proteins including gp120 contribute to this process. A number of different pathways induce HIV-associated CD4 T-lymphocyte apoptosis and apoptosis of uninfected bystander cells is particularly associated with increased susceptibility to Fas. Other viruses including hepatitis viruses and the human herpesviruses also modulate apoptosis. Bacterial infection induces apoptosis which is frequently mediated by the direct activation of caspases in the absence of death receptor ligation. Bacterial induction of apoptosis may either be due to bacterial factors such as the invasin IpaB of Shigella flexneri or be the result of host immune responses which control infection as demonstrated in infections due to Mycobacterium spp. Apoptosis may be modulated by therapeutic strategies, such as antiretroviral therapy, and an improved understanding of infection-associated apoptosis modulation will aid the design of novel therapeutic approaches to control infectious diseases.
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PMID:Apoptotic cell death in the pathogenesis of infectious diseases. 1154 64

In the present study, we evaluated the role of CCR2 in a model of viral-induced neurologic disease. An orchestrated expression of chemokines, including the CCR2 ligands monocyte chemoattractant protein-1/CCL2 and monocyte chemoattractant protein-3/CCL7, occurs within the CNS following infection with mouse hepatitis virus (MHV). Infection of mice lacking CCR2 (CCR2(-/-)) with MHV resulted in increased mortality and enhanced viral recovery from the brain that correlated with reduced (p < or = 0.04) T cell and macrophage/microglial (determined by F4/80 Ag expression, p < or = 0.004) infiltration into the CNS. Moreover, MHV-infected CCR2(-/-) mice displayed a significant decrease in Th1-associated factors IFN-gamma (p < or = 0.001) and RANTES/CCL5 (p < or = 0.002) within the CNS as compared with CCR2(+/+) mice. Further, peripheral CD4(+) and CD8(+) T cells from immunized CCR2(-/-) mice displayed a marked reduction in IFN-gamma production in response to viral Ag and did not migrate into the CNS of MHV-infected recombination-activating gene (RAG)1(-/-) mice following adoptive transfer. In addition, macrophage/microglial infiltration into the CNS of RAG1(-/-) mice receiving CCR2(-/-) splenocytes was reduced (p < or = 0.05), which correlated with a reduction in the severity of demyelination (p < or = 0.001) as compared with RAG1(-/-) mice receiving splenocytes from CCR2(+/+) mice. Collectively, these results indicate an important role for CCR2 in host defense and disease by regulating leukocyte activation and trafficking.
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PMID:Lack of CCR2 results in increased mortality and impaired leukocyte activation and trafficking following infection of the central nervous system with a neurotropic coronavirus. 1159 87

Hepatitis virus infections are frequent in patients suffering from HIV infection due to similar transmission routes of these viruses. In addition, hepatitis virus infections lead to impaired survival in HIV positive patients. The recently discovered flavivirus GB virus C (alias Hepatitis G Virus) was initially believed to be another hepatitis virus. While there is still some minor discussion whether GB virus C (GBV-C) plays a role in fulminant hepatic failure, there is no evidence that this virus is responsible for chronic liver disease. Thus this 'orphan virus' still seeks its disease. In this review we concentrate on the published data concerning the co-infection of GBV-C and HIV. By summarizing the studies available, we show evidence for a beneficial influence of GBV-C on HIV infection. Many studies demonstrated a high prevalence of GBV-C infection in HIV positive patients due to its parenteral and sexual transmission. However, in contrast to the expectations, GBV-C does not aggravate the course of patients suffering from HIV infection. Even though not uniformly found, one often sees higher CD4 counts in patients with ongoing GBV-C viral replication. Likewise, a lower viral load appears to be accompanied by the presence of GBV-C RNA in the serum. In addition, longitudinal studies indicate that GBV-C infection slows down the progression to AIDS and eventually to death. GBV-C probably influences HIV infection associated disease by either directly inhibiting HIV replication or enhancing the immune competence to cope with HIV. Still the definitive mechanism how GBV-C could inhibit the progression to AIDS and eventually death needs to be identified.
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PMID:GB virus-C infection in patients infected with the human immunodeficiency virus. 1167 17

Intracerebral inoculation with mouse hepatitis virus strain A59 results in viral replication in the CNS and liver. To investigate whether B cells are important for controlling mouse hepatitis virus strain A59 infection, we infected muMT mice who lack membrane-bound IgM and therefore mature B lymphocytes. Infectious virus peaked and was cleared from the livers of muMT and wild-type mice. However, while virus was cleared from the CNS of wild-type mice, virus persisted in the CNS of muMT mice. To determine how B cells mediate viral clearance, we first assessed CD4(+) T cell activation in the absence of B cells as APC. CD4(+) T cells express wild-type levels of CD69 after infection in muMT mice. IFN-gamma production in response to viral Ag in muMT mice was also normal during acute infection, but was decreased 31 days postinfection compared with that in wild-type mice. The role of Ab in viral clearance was also assessed. In wild-type mice plasma cells appeared in the CNS around the time that virus is cleared. The muMT mice that received A59-specific Ab had decreased virus, while mice with B cells deficient in Ab secretion did not clear virus from the CNS. Viral persistence was not detected in FcR or complement knockout mice. These data suggest that clearance of infectious mouse hepatitis virus strain A59 from the CNS requires Ab production and perhaps B cell support of T cells; however, virus is cleared from the liver without the involvement of Abs or B cells.
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PMID:Antibody is required for clearance of infectious murine hepatitis virus A59 from the central nervous system, but not the liver. 1167 40


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