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

Most RNA viruses encode their own RNA polymerases for genome replication, and increasing numbers of them appear to be capable of undergoing RNA recombination. Here, we provide the first report of intergenotypic recombination in hepatitis delta virus (HDV), the only animal RNA virus that requires host RNA polymerase(s) for viral replication. In vivo, we analyzed RNA species derived from the serum of a patient with mixed genotype I and genotype IIb HDV infection by using multiple restriction fragment length polymorphism (RFLP) assays and sequence analysis of cloned reverse transcription (RT)-PCR products. Six HDV recombinants were isolated from 101 tested clones, and HDV recombination in this patient was further confirmed by RT-PCR with genotype-specific primer pairs. Analysis of the recombination junctions suggested that the HDV genome rearrangement occurred through faithful homologous recombination. We then used an RNA cotransfection cell culture system to investigate HDV RNA recombination in vitro. We found that HDV recombinants could indeed be detected in the transfected cells; some of these possessed recombination junctions identical to those identified in vivo. Furthermore, using a PCR-independent RNase protection assay, we were able to readily identify the recombined HDV RNA species in cultured cells. Taken together, our results demonstrate that HDV RNA recombination occurs in both natural HDV infections and cultured cells, thereby presenting a novel mechanism for HDV evolution.
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PMID:RNA recombination of hepatitis delta virus in natural mixed-genotype infection and transfected cultured cells. 1568 24

The woodchuck together with the woodchuck hepatitis virus (WHV) is an excellent model to study the pathogenesis of hepadnaviral infections. Chronic WHV infection causes severe liver disease and hepatocellular carcinoma in woodchucks. The mechanism of viral clearance is not fully understood, interferons seem to play a major role in down-regulating viral replication prior to elimination of infected hepatocytes. We investigated on the pattern of cytokine and T-cell-marker expression in livers of woodchucks chronically infected with WHV. RNase-protection-assay (RPA) was used to determine mRNA of woodchuck specific genes (TNF-alpha, IFN-gamma, IL-15, CD3, CD4, CD8). Serial liver biopsies were performed daily or weekly in eight chronic WHV-carrier woodchucks. Cytokine/T-cell-marker expression differed significantly between the time points up to +/-50% within each woodchuck. The different expression patterns of cytokines or T-cell-markers did not correlate to the (weak) fluctuations in the viremia but may explain the observed fluctuations in the WHV/HBV-load in chronically infected individuals. Furthermore, we observed associations between cytokine and T-cell-marker expression. The marginal fluctuations in viremia during the chronic infection may indicate, that, once the chronic hepadnaviral infection is established, cytokines/interferons expressed endogenously (i.e. not vector-borne or injected) play only a minor role.
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PMID:Fluctuation of the cytokine expression in the liver during the chronic woodchuck hepatitis virus (WHV) infection is not related to viral load. 1604 39

Background. In situ hybridization (ISH) with high sensitivity has been requested to demonstrate hepatitis C virus (HCV) RNA in formalin-fixed, paraffin-embedded (FFPE) sections of the liver. Methods. ISH employing a locked-nucleic-acid- (LNA-)modified oligonucleotide probe and biotin-free catalyzed signal amplification system (CSAII) was applied to HCV-RNA detection in the liver tissue. Nested reverse-transcription polymerase chain reaction (RT-PCR) was performed for HCV genotyping using total RNA extracted from FFPE sections. The target tissues included FFPE tissue sections of humanized livers in HCV-infected chimeric mice (HCV genotypes 1a, 1b, and 2a and noninfected) and of needle-biopsied livers from HCV-infected patients. Results. HCV-RNA was demonstrated with the ISH technique in HCV-infected liver tissues from both chimeric mice and 9 (82%) of 11 patients with HCV infection. The HCV signals were sensitive to RNase. Nested RT-PCR confirmed the genotype in 8 (73%) of 11 livers (type 1b: 6 lesions and type 2a: 2 lesions). HCV-RNA was not identified in chronic hepatitis B lesions, fatty liver, autoimmune hepatitis, and hepatocellular carcinoma. Conclusion. ISH using the LNA-modified oligonucleotide probe and CSAII was applicable to detecting HCV-RNA in routinely prepared FFPE liver specimens.
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PMID:Demonstration of hepatitis C virus RNA with in situ hybridization employing a locked nucleic Acid probe in humanized liver of infected chimeric mice and in needle-biopsied human liver. 2385 23


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