Publications by authors named "Olivier Schorr"

Aims Of The Study: Since 2014, the Swiss Hepatitis Strategy (SHS) has targeted the elimination of Hepatitis C Virus (HCV) in Switzerland. The epidemiology of HCV is diverse across Swiss cantons, therefore cantonal-level screening and treatment strategies should be developed. This study aimed to identify scenarios to achieve HCV elimination in the canton of Bern by 2030.

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Objective: To evaluate the decrease of cartilage destruction by a novel orally active and specific matrix metalloproteinase 13 (MMP-13) inhibitor in three different animal models of rheumatoid arthritis (RA).

Materials And Methods: The SCID mouse co-implantation model of RA, the collagen-induced arthritis (CIA) model in mice and the antigen-induced arthritis model (AIA) in rabbits were used.

Results: In the SCID mouse co-implantation model, the MMP-13 inhibitor reduced cartilage destruction by 75%.

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Objective: To study possible mechanisms that mediate induction of the recently described adipocytokine pre-B cell colony-enhancing factor (PBEF) in joints of patients with rheumatoid arthritis (RA), and to analyze whether levels of PBEF correlate with disease severity and whether PBEF itself has the potential to act as a proinflammatory and destructive mediator in RA.

Methods: RA synovial fibroblasts (RASFs) and monocytes were stimulated with Toll-like receptor (TLR) ligands, cytokines, and recombinant human PBEF or were transfected with PBEF expression constructs or with PBEF-specific small interfering RNA. Production of interleukin-6 (IL-6), IL-8, and tumor necrosis factor alpha (TNFalpha) was measured by enzyme-linked immunosorbent assay, and expression of matrix metalloproteinases (MMPs) was assessed by real-time polymerase chain reaction.

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Background/aims: Duck hepatitis B virus (DHBV) replication is up-regulated by cell cycle during the early infection of primary duck but the effect of cell cycle on DHBV replication in chronically infected hepatocyte is not known.

Methods: Hepatocytes obtained from DHBV congenitally infected embryos were used. Cell proliferation was controlled by addition of liver growth factors and the impact on viral replication analyzed.

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Objective: To assess the expression of Toll-like receptor 3 (TLR-3) protein in synovial tissues and cultured synovial fibroblasts obtained from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to investigate the consequences of stimulation of cultured synovial fibroblasts with TLR-3 ligands.

Methods: TLR-3 expression in synovial tissues was determined by immunohistochemistry and immunofluorescence, and expression in cultured RA synovial fibroblasts (RASFs) was determined by fluorescence-activated cell sorting and real-time polymerase chain reaction techniques. TLR-3 signaling was assessed by incubating RASFs with poly(I-C), lipopolysaccharide, palmitoyl-3-cysteine-serine-lysine-4, or necrotic synovial fluid cells from RA patients in the presence or absence of hydroxychloroquine or Benzonase.

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Recent evidence highlighted the role of Toll-like receptors (TLRs) as key recognition structures of the innate immune system. The activation of TLRs initiates the production of inflammatory cytokines, chemokines, tissue destructive enzymes, and type I interferons. In addition, TLR signalling plays an important role in the activation and direction of the adaptive immune system by the upregulation of costimulatory molecules of antigen presenting cells.

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Background/aims: Peptide nucleic acids (PNAs) appear as promising new antisense agents, that have not yet been examined as hepatitis B virus (HBV) inhibitors. Our aim was to study the ability of PNAs targeting the duck HBV (DHBV) encapsidation signal epsilon to inhibit reverse transcription (RT) and to compare their efficacy with phosphorothioate oligodeoxynucleotides (S-ODNs).

Methods: The effect of two partly overlapping PNAs targeting epsilon and of analogous S-ODNs was tested in cell-free transcription and translation system for DHBV RT expression.

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In contrast to 5'-O-carbonate 3TC derivatives (23, 24), which are clearly 3TC prodrugs, the corresponding 3TC carbamates (15-21 and 25), found to be very stable compounds with respect to enzymatic hydrolysis (cellular lysates and culture cell media) and still active on both HIV-1 and HBV infected cells, may not be 3TC prodrugs. The antiviral properties as well as the mechanism of action of 3TC analogues have been studied and evaluated.

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To design new strategies of antiviral therapy for chronic hepatitis B, we have evaluated the antiviral activity of the combination of amdoxovir (DAPD), emtricitabine [(-)FTC], and clevudine (L-FMAU) in the duck hepatitis B virus (DHBV) model. Using their triphosphate (TP) derivatives in a cell-free system expressing a wild-type active DHBV reverse transcriptase (RT), the three dual combinations exhibited a greater additive inhibitory effect on viral minus-strand DNA synthesis than the single drugs, according to the Bliss independence model. Both dual combinations with DAPD TP were the most efficient while the triple combination increased the inhibitory effect on the DHBV RT activity in comparison with the dual association, however, without additive effect.

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The elimination of viral covalently closed circular DNA (CCC DNA) from the nucleus of infected hepatocytes is an obstacle to achieving sustained viral clearance during antiviral therapy of chronic hepatitis B virus (HBV) infection. The aim of our study was to determine whether treatment with adefovir, a new acyclic nucleoside phosphonate, the prodrug of which, adefovir dipivoxil, is in clinical evaluation, is able to suppress viral CCC DNA both in vitro and in vivo using the duck HBV (DHBV) model. First, the effect of adefovir on viral CCC DNA synthesis was examined with primary cultures of DHBV-infected fetal hepatocytes.

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