Search results for "Virology"

Determinants of Substrate Specificity in the NS3 Serine Proteinase of the Hepatitis C Virus

1997

AbstractProcessing of the nonstructural polyprotein of the hepatitis C virus (HCV) requires the serine-type proteinase located in the amino-terminal domain of NS3. To identify residues within NS3 determining substrate specificity, a mutation analysis was performed. Using sequence alignments and three-dimensional structure predictions, amino acids assumed to be important for specificity were replaced and the enzymes were tested in an intracellulartrans-processing assay for their effects on cleavage of an NS4B-5B substrate. For some of the substitutions at positions 133, 134, 135, 136, 138, 152, 155, 157, and 169, slightly reduced processing efficiencies were observed but in no case was the s…

Faldaprevir (BI 201335), BI 207127 and ribavirin oral therapy for treatment-naive HCV genotype 1: SOUND-C1 final results

2013

Background Faldaprevir (BI 201335) and deleobuvir (BI 207127) are direct-acting antiviral agents under development for the treatment of chronic HCV infection. This article describes the final results of the Phase Ib SOUND-C1 study that evaluated the interferon-free oral combination of faldaprevir, deleobuvir and ribavirin in 32 treatment-naive patients infected with HCV genotype 1. Methods Patients were randomized to receive deleobuvir 400 mg ( n=15) or 600 mg ( n=17) three times daily plus faldaprevir 120 mg once daily and weight-based ribavirin for 4 weeks. Interferon-free therapy was followed by response-guided faldaprevir plus pegylated interferon-α2a/ribavirin to week 24 or 48. Results…

Diversity of ankA and msp4 genes of Anaplasma phagocytophilum in Slovenia.

2015

Granulocytic anaplasmosis is a tick transmitted emerging disease in Europe and worldwide. The agent, Anaplasma phagocytophilum is transmitted by ticks of the genus Ixodes and causes infections in humans and domestic animals. The analysis of different target genes showed that in nature several genetic variants of A. phagocytophilum were present. The purpose of our study was to genetically characterize A. phagocytophilum strains from eight humans, 16 dogs, 12 wild boars, one bear and 18 tick pools from Slovenia. Therefore, the ankA and msp4 genes of A. phagocytophilum were chosen. The same genetic ankA and msp4 variant of A. phagocytophilum was detected in humans, wild boar and a part of the …

Microsporidia and Its Relation to Crohn's Disease. A Retrospective Study

2013

Background: The cause of Crohn's Disease (CD) remains unknown. Recently a decrease in the global lymphocyte population in the peripheral blood of CD patients has been reported. This decrease was more evident in gamma delta T lymphocytes, especially gamma delta CD8+T subsets. Furthermore, a decrease of IL-7 was also observed in these patients. We propose the hypothesis that microsporidia, an obligate intracellular opportunistic parasite recently related to fungi, in CD patients can take advantage of the lymphocytes and IL-7 deficits to proliferate and to contribute to the pathophysiology of this disease. Methods and Findings: In this case-control study, serum samples were collected from 36 C…

New Isolate ofMalacosoma neustriaNuclear Polyhedrosis Virus in Latvia

1998

Factors influencing the interaction of herpes simplex virus glycoprotein C with the third component of complement.

1992

The factors influencing the interaction of herpes simplex virus (HSV) glycoprotein C (gC) with the third component of complement (C3) were investigated in this study. The ability of gC of HSV type 1 (gC-1) to bind to the C3b fragment of C3 was found to be influenced by cell specific processing of gC-1 in a different manner, binding being remarkably enhanced in some cell lines following removal of sialic acid residues. Testing several intertypic recombinants of HSV we found that only strains expressing gC-1 exhibited binding to C3b, even though their genome consisted mainly of HSV-2 sequences in some recombinants. Expression of type-2 glycoproteins gB, gD, gE, gG, gH, and gI did not alter th…

Antiretroviral genotypic resistance in plasma RNA and whole blood DNA in HIV-1 infected patients failing HAART

2008

The extent to which HIV-1 proviral DNA mutations cause clinically relevant antiretroviral resistance is still controversial. Paired plasma HIV-1 RNA and whole blood DNA were compared in patients failing HAART to investigate if the additional knowledge of archived mutations could improve the selection of potentially active drugs. Seventy-three HIV-1-infected patients with first/second HAART failure were studied before starting a new regimen based on RNA genotyping. Follow-up data after a 12-week therapy were available. DNA genotyping was retrospectively performed on stored whole blood samples and mutational profiles were compared to those from RNA. The mean number of IAS pol mutations was si…

Profile of leukocyte-endothelial cell interactions induced in venules and arterioles by nucleoside reverse-transcriptase inhibitors in vivo.

2013

Background There is controversy regarding cardiovascular (CV) toxicity of the nucleoside reverse-transcriptase inhibitors used to treat human immunodeficiency virus infection. Methods We evaluated the effects of nucleoside reverse-transcriptase inhibitors on leukocyte-endothelium interactions, a hallmark of CV diseases, in rat mesenteric vessels using intravital microscopy and in human arterial cells using a flow chamber system. Results Abacavir and didanosine increased rolling, adhesion and emigration in rat vessels. These effects were reversed with antibodies against Macrophage-1 antigen (Mac-1) or intercellular adhesion molecule 1 and were reproduced in human cells. Lamivudine, zidovudin…

Characterization of liver cytokeratin as a major target antigen of anti-SLA antibodies.

1990

Abstract Anti-SLA antibodies characterize a newly defined subgroup of patients with autoimmune chronic active hepatitis. The aim of the present study was the immunochemical characterization of the target antigen(s) of anti-SLA antibodies. Anti-SLA-positive sera were found to contain high titres of anti-cytokeratin antibodies. In immunoblotting analyses with 100 000 × g supernatants of human liver homogenates (S-100) these sera recognized various proteins with a molecular mass of 40–60 kDa. These proteins were also recognized by monoclonal anti-cytokeratin antibodies. Two-dimensional co-electrophoresis and immunoblotting analysis of S-100 and liver cytokeratins showed that anti-SLA antibodie…

CrELISA: a fast and robust enzyme-linked immunosorbent assay bypassing the need for purification of recombinant protein

2004

A multitude of antigens has been recently identified by screening of cDNA expression libraries derived from human tumors with autologous sera. Using a phage autoantibody assay and small panels of sera derived from cancer patients or controls it has been shown that some of these antigens display cancer-associated autoantibody responses. The diagnostic and prognostic significance of these potentially cancer-related autoantibodies remains unclear until large-scale assays are developed and serological data are available for hundreds of cancer patients and controls. The major bottleneck for the development of large-scale assays are the cloning, expression and the purification of each of the resp…