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RNA Detection (rna + detection)
Selected AbstractsGBV-C/hepatitis G virus infection and non-Hodgkin lymphoma: a case control studyINTERNATIONAL JOURNAL OF CANCER, Issue 12 2010Mel Krajden Abstract We investigated whether there was an association between GBV-C viremia and the development of non-Hodgkin lymphoma (NHL) in 553 NHL cases and 438 controls from British Columbia, Canada. Cases were aged 20,79, diagnosed between March 2000 and February 2004, and resident in Greater Vancouver or Victoria. Cases and controls were tested for GBV-C RNA by RT-PCR and positive samples were genotyped. Overall, GBV-C RNA was detected in 4.5% of NHL cases vs. 1.8% of controls [adjusted odds ratio (OR) = 2.72, 95% confidence interval (CI) = 1.22,6.69]. The association between GBV-C RNA detection and NHL remained even after individuals with a history of prior transfusion, injection drug use and hepatitis C virus sero-positivity were excluded. GBV-C viremia showed the strongest association with diffuse large B cell lymphoma (adjusted OR = 5.18, 95% CI = 2.06,13.71). Genotyping was performed on 29/33 GBV-C RNA positive individuals; genotypes 2a (n = 22); 2b (n = 5) and 3 (n = 2) were identified, consistent with the distribution of genotypes found in North America. This is the largest case-control study to date associating GBV-C viremia and NHL risk. As GBV-C is known to be transmitted through blood products this may have important implications for blood safety. [source] Multicenter quality control of the detection of HIV-1 genome in semen before medically assisted procreationJOURNAL OF MEDICAL VIROLOGY, Issue 7 2006Christophe Pasquier Abstract Couples in whom the man is HIV-1-positive may use medically assisted procreation in order to conceive a child without contaminating the female partner. But, before medically assisted procreation, the semen has to be processed to exclude HIV and tested for HIV nucleic acid before and after processing. The performance was evaluated of the technical protocols used to detect and quantify HIV-1 in 11 centers providing medically assisted procreation for couples with HIV-1 infected men by testing panels of seminal plasma and cells containing HIV-1 RNA and/or DNA. The performance of these tests varied due to the different assays used. False positive results were obtained in 14,19% of cases. The sensitivity for RNA detection in seminal plasma was 500,1,000 RNA copies/ml, over 500 RNA copies/106 cells in semen cells, and for DNA detection in semen cells 50,500 DNA copies/106 cells. The use of silica-based extraction seemed to increase the assay performance, whereas the use of internal controls to detect PCR inhibitor did not. This first quality control highlights the need for technical improvements of the assays to detect and quantify HIV in semen fractions and for regular evaluation of their performance. J. Med. Virol. 78:877,882, 2006. © 2006 Wiley-Liss, Inc. [source] Mosquito cells bind and replicate hepatitis C virusJOURNAL OF MEDICAL VIROLOGY, Issue 1 2001Raphaële Germi Abstract Several studies have demonstrated some hepatitis C virus (HCV) replication in lymphocyte and hepatocyte cell lines such as in African green monkey Vero cells. The aim of the present study was to select other cell lines able to bind and replicate HCV. Human hepatoma PLC/PRF/5 cells, human lymphoma Namalwa cells, Vero and mosquito AP61 cells were inoculated with HCV-positive plasma, washed six times and examined for the presence of the viral genome at different times post infection, using an RT-PCR method. Binding of HCV to cells was estimated by HCV RNA detection in cells 2 hr after inoculation and in the last wash of these cells. Successive virus passages in cells were carried out. All the cells studied were able to bind HCV but only AP61 and Vero cells provided evidence of replication and production of infectious virus: virus RNA was detected during 28 days post-infection in four successive virus passages. CD81 molecules, a putative HCV receptor, were detected by cytofluorometric analysis. Vero cells express CD81 molecules whereas these molecules were not detected on AP61 cells. It is suggested that other receptors are involved in HCV binding to Vero and AP61 cells. J. Med. Virol. 64:6,12, 2001. © 2001 Wiley-Liss, Inc. [source] Chronic hepatitis C and persistent occult hepatitis C virus infection are characterized by distinct immune cell cytokine expression profilesJOURNAL OF VIRAL HEPATITIS, Issue 8 2009T. N. Q. Pham Summary., Hepatitis C virus (HCV) replicates in immune cells in both chronic hepatitis C (CHC) and occult HCV infection, but the extent of virus replication in this compartment in these opposing infection forms varies greatly. It was unknown whether this could be linked to HCV genotype or to differences in host gene expression shaping the immune response, and whether HCV replication in immune cells is sensitive to endogenous antiviral cytokines. In this study, we uncovered that significantly greater HCV load in peripheral blood mononuclear cells (PBMC), but not in plasma, coincided with HCV genotypes 2 and 3 in CHC, but with genotype 1 in residual occult infection after clinical resolution of hepatitis C. Moreover, PBMC from individuals with occult infection transcribed significantly greater levels of IFN-,, IFN-, and TNF-,, but less interleukin (IL)-10 than those from CHC. In CHC, PBMC with low HCV load expressed significantly more IFN-, but less IL-12 than did cells with high virus content. In occult infection, HCV RNA detection in PBMC was associated with much lower IFN-, and IL-12 expression. Further, HCV replication in T lymphocytes could be completely eliminated by activation of endogenous IFN-, in CHC, but of IFN-, in occult infection. In conclusion, CHC and persistent occult HCV infection are characterized by clearly different profiles of antiviral cytokine response in circulating immune cells which are also different from those of healthy individuals. Higher expression of IL-10, combined with lower transcription of IFN-,, IFN-, and TNF-,, is associated with a more robust HCV replication in immune cells. [source] Fulminant liver failure from acute autochthonous hepatitis E in France: description of seven patients with acute hepatitis E and encephalopathyJOURNAL OF VIRAL HEPATITIS, Issue 5 2007J. M. Péron Summary., Fulminant hepatitis E has not been well characterized in industrialized countries. The aim of this study was to prospectively describe patients with acute hepatitis E presenting as fulminant hepatic failure, i.e. with encephalopathy and prothrombin index <50%. Between February 1997 and April 2005, seven patients with encephalopathy were diagnosed with acute hepatitis E using viral RNA detection. These patients were compared with 33 patients diagnosed with a mild form (absence of encephalopathy) of acute hepatitis E during the same time period. Patients were 65 ± 11 years old. Five were active drinkers and six had chronic liver disease. All hepatitis E virus sequences evaluated (5/7) were of genotype 3. All patients but two died (71%). Four patients had no travel history. When compared with patients with a mild form of acute hepatitis E, active alcohol abuse and chronic liver disease were more frequent in patients with the severe form. Duration of hospitalization was longer. Aspartate transferase and bilirubin levels were significantly higher. Prothrombin index and accelerin levels were lower and death was more frequent. Acute nontravel-associated hepatitis E can appear as fulminant hepatitis with encephalopathy and coagulation disorders. Prognosis is severe and this may be due to the age at which it occurs and frequent underlying chronic liver disease. [source] One-step RNA pathogen detection with reverse transcriptase activity of a mutated thermostable Thermus aquaticus DNA polymeraseBIOTECHNOLOGY JOURNAL, Issue 2 2010Ramon Kranaster Abstract We describe the cloning and characterization of a mutated thermostable DNA polymerase from Thermus aquaticus (Taq) that exhibits an increased reverse transcriptase activity and is therefore designated for one-step PCR pathogen detection using established real-time detection methods. We demonstrate that this Taq polymerase mutant (Taq M1) has similar PCR sensitivity and nuclease activity as the respective Taq wild-type DNA polymerase. In addition, and in marked contrast to the wild-type, Taq M1 exhibits a significantly increased reverse transcriptase activity especially at high temperatures (>60°C). RNA generally hosts highly stable secondary structure motifs, such as hairpins and G-quadruplexes, which complicate, or in the worst case obviate, reverse transcription (RT). Thus, RT at high temperatures is desired to weaken or melt secondary structure motifs. To demonstrate the ability of Taq M1 for RNA detection of pathogens, we performed TaqMan probe-based diagnostics of Dobrava viruses by one-step RT-PCR. We found similar detection sensitivities compared to commercially available RT-PCR systems without further optimization of reaction parameters, thus making this enzyme highly suitable for any PCR probe-based RNA detection method. [source] Hepatitis E virus as a newly identified cause of acute viral hepatitis during human immunodeficiency virus infectionCLINICAL MICROBIOLOGY AND INFECTION, Issue 12 2008P. Colson Abstract The recent description of chronic hepatitis E in organ transplant recipients deserves increased awareness in the context of hepatitis E virus (HEV) infection in immunocompromised individuals. Reported here is what is apparently the first PCR-documented case of acute hepatitis E in a human immunodeficiency virus (HIV)-1-infected patient. The CD4+ T-lymphocyte count was 246/mm3. The IgM anti-HEV antibody and HEV RNA tests results from serum were positive. Hepatitis was benign, and chronic HEV infection was ruled out. The HEV genotype was 3f. The patient did not report recent travel abroad. HEV should be tested in HIV-infected individuals presenting with acute hepatitis. HEV RNA detection is useful in diagnosing HEV infection and in monitoring recovery. [source] | |||||||||||||