Nathan Osman

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Clinical studies have shown that integrase strand transfer inhibitors can be used to treat HIV-1 infection. Although the first-generation integrase inhibitors are susceptible to the emergence of resistance mutations that impair their efficacy in therapy, such resistance has not been identified to date in drug-naïve patients who have been treated with the(More)
Drug resistance mutations (DRMs) have been reported for all currently approved anti-HIV drugs, including the latest integrase strand transfer inhibitors (INSTIs). We previously used the new INSTI dolutegravir (DTG) to select a G118R integrase resistance substitution in tissue culture and also showed that secondary substitutions emerged at positions H51Y and(More)
First-generation integrase strand-transfer inhibitors (INSTIs), such as raltegravir (RAL) and elvitegravir (EVG), have been clinically proven to be effective antiretrovirals for the treatment of HIV-positive patients. However, their relatively low genetic barrier for resistance makes them susceptible to the emergence of drug resistance mutations. In(More)
BACKGROUND The results of several clinical trials suggest that the integrase inhibitor dolutegravir may be less prone than other drugs to the emergence of HIV drug resistance mutations in treatment-naive patients. We have shown that the R263K mutation commonly emerged during tissue culture selection studies with dolutegravir and conferred low levels of(More)
UNLABELLED Dolutegravir (DTG) is the latest antiretroviral (ARV) approved for the treatment of human immunodeficiency virus (HIV) infection. The G118R substitution, previously identified with MK-2048 and raltegravir, may represent the initial substitution in a dolutegravir resistance pathway. We have found that subtype C integrase proteins have a low(More)
OBJECTIVES Of the currently approved HIV integrase strand transfer inhibitors (INSTIs), dolutegravir has shown greater efficacy than raltegravir at suppressing HIV-1 replication in treatment-experienced individuals. Biochemical experiments have also shown that dolutegravir has a longer dissociative half-life when bound to HIV integrase than does(More)
OBJECTIVES Dolutegravir is an integrase strand-transfer inhibitor that has shown unprecedented robustness against the emergence of HIV drug-resistant strains in treatment-naive individuals. The R263K substitution in integrase was identified through culture selection as a resistance-associated substitution for dolutegravir and was recently detected in two(More)
BACKGROUND Codon usage bias has been described for various organisms and is thought to contribute to the regulation of numerous biological processes including viral infections. HIV-1 codon usage has been previously shown to be different from that of other viruses and man. It is evident that the antiretroviral drugs used to restrict HIV-1 replication also(More)
We evaluated Sofosbuvir (SOF), the anti-hepatitis C virus prodrug of β-d-2'-deoxy-2'-α-fluoro-2'-β-C-methyluridine-5'-monophosphate, for potential inhibitory activity against DENV replication. Both cell-based and biochemical assays, based on use of purified DENV full-length NS5 enzyme, were studied. Cytopathic effect protection and virus yield reduction(More)
Introduction: Prior studies in Brazil have shown that the group of men who have sex with men (MSM) is the most severely affected by HIV. In 2015, a multi-disciplinary team launched a community-wide intervention in the city of Curitiba to evaluate the acceptability, uptake and cost-effectiveness of multiple HIV testing services (HTS). The current study aims(More)