Rapid emergence of telaprevir resistant hepatitis C virus strain from wildtype clone in vivo.

Unlabelled: Telaprevir is a potent inhibitor of hepatitis C virus (HCV) NS3-4A protease. However, the emergence of drug-resistant strains during therapy is a serious problem, and the susceptibility of resistant strains to interferon (IFN), as well as the details of the emergence of mutant strains in vivo, is not known. We previously established an infectious model of HCV using human hepatocyte chimeric mice.

Elimination of hepatitis C virus by short term NS3-4A and NS5B inhibitor combination therapy in human hepatocyte chimeric mice.

Background & Aims: The current treatment regimen for chronic hepatitis C virus (HCV) infection is peg-interferon plus ribavirin combination therapy. The majority of developing therapeutic strategies also contain peg-interferon with or without ribavirin. However, interferon is expensive and sometimes intolerable for some patients because of severe side effects.

Practical evaluation of a mouse with chimeric human liver model for hepatitis C virus infection using an NS3-4A protease inhibitor.

A small-animal model for hepatitis C virus (HCV) infection was developed using severe combined immunodeficiency (SCID) mice encoding homozygous urokinase-type plasminogen activator (uPA) transplanted with human hepatocytes. Currently, limited information is available concerning the HCV clearance rate in the SCID mouse model and the virion production rate in engrafted hepatocytes. In this study, several cohorts of uPA(+/+)/SCID(+/+) mice with nearly half of their livers repopulated by human hepatocytes were infected with HCV genotype 1b and used to evaluate HCV dynamics by pharmacokinetic and pharmacodynamic analyses of a specific NS3-4A protease inhibitor (telaprevir).

Establishment of an infectious genotype 1b hepatitis C virus clone in human hepatocyte chimeric mice.

The establishment of clonal infection of hepatitis C virus (HCV) in a small-animal model is important for the analysis of HCV virology. A previous study developed models of molecularly cloned genotype 1a and 2a HCV infection using human hepatocyte-transplanted chimeric mice. This study developed a new model of molecularly cloned genotype 1b HCV infection.

Prion removal by nanofiltration under different experimental conditions.

Manufacturing processes used in the production of biopharmaceutical or biological products should be evaluated for their ability to remove potential contaminants, including TSE agents. In the present study, we have evaluated scrapie prion protein (PrP Sc) removal in the presence of different starting materials, using virus removal filters of different pore sizes. Following 75 nm filtration, PrP Sc was detected in the filtrate by Western blot (WB) analysis when a "super-sonicated" microsomal fraction derived from hamster adapted scrapie strain 263K (263K MF) was used as the spike material.

Infection of human hepatocyte chimeric mouse with genetically engineered hepatitis C virus and its susceptibility to interferon.

We developed a reverse genetics system of hepatitis C virus (HCV) genotypes 1a and 2a using infectious clones and human hepatocyte chimeric mice. We inoculated cell culture-produced genotype 2a (JFH-1) HCV intravenously. We also injected genotype 1a CV-H77C clone RNA intrahepatically.

Emergence of a novel lamivudine-resistant hepatitis B virus variant with a substitution outside the YMDD motif.

Lamivudine is a major drug approved for treatment of chronic hepatitis B virus (HBV) infection. Emergence of drug-resistant mutants with amino acid substitutions in the YMDD motif is a well-documented problem during long-term lamivudine therapy. Here we report a novel lamivudine-resistant strain of HBV with an intact YMDD motif, which included an amino acid substitution, rtA181T, in the reverse transcriptase (RT) domain of HBV polymerase.

Infection of human hepatocyte chimeric mouse with genetically engineered hepatitis B virus.

Studies of hepatitis B virus (HBV) mutants have been hampered by the lack of a small animal model with long-term infection of cloned HBV. Using a mouse model in which liver cells were highly replaced with human hepatocytes that survived over a long time with mature human hepatocyte function, we performed transmission experiments of HBV. Human serum containing HBV and the virus produced in HepG2 cell lines that transiently or stably transfected with 1.

Potent antibacterial activity of Y-754, a novel benzimidazole compound with selective action against Helicobacter pylori.

Y-754, a novel benzimidazole compound, was investigated for in vitro and in vivo antibacterial activity. Unlike amoxicillin, clarithromycin, and metronidazole, the compound had no activity against common aerobic and anaerobic bacteria other than Helicobacter pylori. The minimum inhibitory concentration of Y-754 against H.

In vitro and in vivo anti- Helicobacter pylori activity of Y-904, a new fluoroquinolone.

Y-904 is a new fluoroquinolone with a broad antimicrobial spectrum. In particular, it has anti- Helicobacter pylori activity superior to that of existing fluoroquinolones. In the present study it was examined for its in vitro antibacterial activity against 51 clinical isolates of H.

Long-term effects of Helicobacter pylori eradication in Mongolian gerbils.

Background: In this study, to clarify whether Helicobacter pylori eradication alters the course of the development of gastric mucosal changes in the stomach, we examined the long-term effects of H. pylori eradication on H. pylori-inoculated gerbils.