Search results for "Virology"

Evidence of Recombination in Intrapatient Populations of Hepatitis C Virus.

2008

Hepatitis C virus (HCV) is a major cause of liver disease worldwide and a potential cause of substantial morbidity and mortality in the future. HCV is characterized by a high level of genetic heterogeneity. Although homologous recombination has been demonstrated in many members of the family Flaviviridae, to which HCV belongs, there are only a few studies reporting recombination on natural populations of HCV, suggesting that these events are rare in vivo. Furthermore, these few studies have focused on recombination between different HCV genotypes/subtypes but there are no reports on the extent of intra-genotype or intra-subtype recombination between viral strains infecting the same patient.…

A new subtype of hepatitis C virus genotype 1: complete genome and phylogenetic relationships of an Equatorial Guinea isolate.

2006

Hepatitis C virus (HCV) is the leading cause of chronic liver disease and is associated with hepatocellular carcinoma. However, there have been few studies on the distribution and genetic diversity of HCV isolates in non-developed countries. Here, the complete genome sequence of an HCV genotype 1 isolate from Equatorial Guinea is reported, the first complete HCV-1 genome of African origin. Phylogenetic analysis revealed that this sequence always grouped with sequences of genotype 1, but did not group clearly with any subtype described so far. An analysis of partial NS5B gene sequences with additional sequences of African origin also failed to find close similarities between the new sequenc…

Genotypic analysis at multiple loci across Kaposi's sarcoma herpesvirus (KSHV) DNA molecules: clustering patterns, novel variants and chimerism

2001

Abstract Background: the genomes of human Kaposi's sarcoma-associated herpesvirus (KSHV) display several levels of DNA sequence heterogeneity and subgrouping that show distinctive clustering patterns in related human populations. The four major subtype patterns for the hypervariable ORF-K1 protein correlate closely with the principal diasporas resulting from the migration of modern humans out of East Africa and suggest that KSHV is an ancient human virus that is transmitted primarily in a familial fashion with consequent very low recombination rates. However, chimeric genomes have also been detected, especially with regard to the presence of P versus M alleles of the ORF-K15 gene. Objective…

Reducing treatment duration in patients infected with hepatitis C genotype 1: any need for further studies?

2009

The recommended treatment duration with pegylated interferon-α plus ribavirin for patients infected with hepatitis C virus (HCV) genotype 1 is 48 weeks. Interestingly, a subpopulation of genotype 1 patients experience rapid decreases in HCV RNA levels once treatment is initiated and attain rapid virological response, defined as undetectable HCV RNA at week 4 of therapy. Several studies have shown that these patients can be effectively treated for a 24-week period without any significant decreases in sustained virological response rates. The aim of this review was to consider the existing clinical evidence regarding the use of a 24-week treatment schedule among genotype 1 patients and to hi…

Parvovirus B19 Genotype Specific Amino Acid Substitution in NS1 Reduces the Protein's Cytotoxicity in Culture

2010

A clinical association between idiopathic liver disease and parvovirus B19 infection has been observed. Fulminant liver failure, not associated with other liver-tropic viruses, has been attributed to B19 in numerous reports, suggesting a possible role for B19 components in the extensive hepatocyte cytotoxicity observed in this condition. A recent report by Abe and colleagues (Int J Med Sci. 2007;4:105-9) demonstrated a link between persistent parvovirus B19 genotype I and III infection and fulminant liver failure. The genetic analysis of isolates obtained from these patients demonstrated a conservation of key amino acids in the nonstructural protein 1 (NS1) of the disease-associated genotyp…

The sf32 unique gene of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) is a non-essential gene that could be involved in nucleocapsid o…

2013

A recombinant virus lacking the sf32 gene (Sf32null), unique to the Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), was generated by homologous recombination from a bacmid comprising the complete viral genome (Sfbac). Transcriptional analysis revealed that sf32 is an early gene. Occlusion bodies (OBs) of Sf32null contained 62% more genomic DNA than viruses containing the sf32 gene, Sfbac and Sf32null-repair, although Sf32null DNA was three-fold less infective when injected in vivo. Sf32null OBs were 18% larger in diameter and contained 17% more nucleocapsids within ODVs than those of Sfbac. No significant differences were detected in OB pathogenicity (50% lethal concentration)…

Genotyping of a nosocomial outbreak of pandemic influenza A/H1N1 2009

2011

Background: Epidemiological surveys have revealed outbreaks of pandemic influenza A (H1N1) 2009 in several different contexts. Molecular characterization of the influenza virus could help to provide a more accurate description of these outbreaks. Objective: To genotype pandemic influenza A (H1N1) 2009 isolates from an epidemiologically defined nosocomial outbreak. Study design: We sequenced the neuraminidase (NA) and hemagglutinin (HA) influenza A (H1N1) 2009 genes from ten HIV-positive patients involved in an epidemiologically defined outbreak in the Clinical Microbiology and Infectious Diseases (CMID) Department. Sequences were aligned to search for specific genetic features of the involv…

Rapid detection and discrimination of fabaviruses by flow-through hybridisation with genus- and species-specific riboprobes

2015

Viruses cause significant damage in agricultural crops worldwide. Disease management requires sensitive and specific tools for virus detection and identification. Also, detection techniques need to be rapid to keep pace with the continuous emergence of new viral diseases. The genus Fabavirus is composed of five viruses infecting many economically important crops worldwide. This research describes the development of a procedure based on flow-through hybridisation (FTH), which is faster than and as sensitive as conventional hybridisation for virus detection in tissue-prints from infected plants. Six digoxigenin-labelled RNA probes were synthesised with two levels of specificity: (a) five spec…

Real-world efficacy of elbasvir/grazoprevir in HCV GT1 infected diabetics: results from the German Hepatitis C Registry

2020

Autoradiographische Beobachtungen �ber den Einbau von3H-Uridin in herpesinduzierten Riesenzellen

1968

Cytological studies indicate that Herpes induced polykaryocytes often contain normal appearing nuclei. Further, virus induced DNA-synthesis was absent in about 20% of the nuclei inside of giant cells as observed by autoradiography. On the other hand, RNA-synthesis seems to be inhibited in all nuclei of such cells as evidenced by reduced3H-uridin incorporation. It is concluded that nuclear RNA-synthesis is blocked by spreading of inhibitory factors.