Transportation and handling of blood samples prior to ammonia measurement in the real life of a large university hospital.

Background: Hyperammonemia is neurotoxic and as such can be a medical emergency. Preanalytical factors greatly influence the blood ammonia concentration results.

Aims And Methods: Ammonia concentrations measured in the real life setting of a large hospital after pneumatic transport of blood samples and various time periods before centrifugation were compared to those based on the indications of the reagent manufacturer.

HIV-1 Vpr inhibits autophagy during the early steps of infection of CD4 T cells.

Background Information: Autophagy is induced during HIV-1 entry into CD4 T cells by the fusion of the membranes triggered by the gp41 envelope glycoprotein. This anti-HIV-1 mechanism is inhibited by the viral infectivity factor (Vif) neosynthesized after HIV-1 integration to allow viral replication. However, autophagy is very rapidly controlled after HIV-1 entry by a still unknown mechanism.

HIV-1 viral infectivity factor interacts with microtubule-associated protein light chain 3 and inhibits autophagy.

Objective: Autophagy, an important antiviral process triggered during HIV-1 entry by gp41-dependent membrane fusion, is repressed in infected CD4+ T cells by an unknown mechanism. The aim of this study was to identify the role of viral infectivity factor (Vif) in the autophagy blockade.

Design/methods: To determine the role of Vif in autophagy inhibition, we used cell lines that express CD4 and CXCR4 and primary CD4+ T cells.