BACKGROUND Prior to receiving a drug from CCR5-antagonist class in HIV therapy, a patient must undergo an HIV tropism test to confirm that his or her viral population uses the CCR5 coreceptor for cellular entry, and not an alternative coreceptor. One approach to tropism testing is to examine the sequence of the V3 region of the HIV envelope, which interacts with the coreceptor. METHODS Viral ...

Background The geno2pheno algorithm (g2p) can give dichotomous tropism based on a selectable “false positive rate” (FPR), reflecting the proportion of individuals inappropriately called “non-R5” and falsely excluded from taking CCR5 antagonists. The effect of replicate genotype measures and different FPR values remains controversial. Here we characterize different FPR “cut-points” in predicting...

Several protozoan and helminth parasites can affect the central nervous system. In some cases the parasite may have a tropism for the central nervous system (CNS) and this represents the primary affect of the pathogen. In many cases, though, the pathogen does not exhibit a specific tropism for the CNS and affects many other organs and tissues. However, the symptoms associated with the invasion ...

The experimental study of the pharmacokinetic characteristics a new pyrrole derivative carnosine, pyrrolylcarnosine, was carried out. Based on results experiment, basic parameters drug are expected. tissues and organs bioavailability studied. tropism pyrrolylcarnosine to elimination ability penetrate into heart muscle tissue were shown.

In human cytomegalovirus (HCMV), tropism to epithelial and endothelial cells is dependent upon a pentameric complex (PC). Given the structure of the placenta, the PC is potentially an important neutralizing antibody target antigen against congenital infection. The guinea pig is the only small animal model for congenital CMV. Guinea pig cytomegalovirus (GPCMV) potentially encodes a UL128-131 HCM...

Influenza virus tissue tropism defines the host cells and tissues that support viral replication and contributes to determining which regions of the respiratory tract are infected in humans. The location of influenza virus infection along the respiratory tract is a key determinant of virus pathogenicity and transmissibility, which are at the basis of influenza burdens in the human population. A...

There have been few studies on the concordance between phenotypic assays for predicting human immunodeficiency virus type 1 (HIV-1) coreceptor usage. The sensitivity of ultradeep pyrosequencing combined with genotyping tools is similar to that of phenotypic assays for detecting minor CXCR4-using variants. We evaluated the agreement between two phenotypic assays, the Toulouse tropism test (TTT) ...

Four of six specific pathogen-free cats were infected after intravaginal exposure to molecularly cloned lymphotropic but non-Crandell feline kidney (CRFK)-tropic feline immunodeficiency virus strain TM2 and its AP-1 deletion mutant. The sequences of the env V3-to-V5 region which defines the CRFK tropism were unchanged in the infected cats through the infection. These data suggest that the strai...

Background A4001078 is a study in therapy naive patients of Maraviroc (MVC) plus boosted atazanavir. The Trofile ES (ESTA) was used to determine tropism at Screening. Few re-analyses of genotypic tropism have examined all screened and non-reportable (NR) populations. We aimed to define correlations between methods at screening and evaluate the quantity of X4 using virus in discordant results us...

Characterization of residual plasma virus during antiretroviral therapy (ART) is a high priority to improve understanding of HIV-1 pathogenesis and therapy. To understand the evolution of HIV-1 pol and env genes in viremic patients under selective pressure of ART, we performed longitudinal analyses of plasma-derived pol and env sequences from single HIV-1 genomes. We tested the hypotheses that ...