Acid Sphingomyelinase Promotes Endothelial Stress Response in Systemic Inflammation and Sepsis.

The pathophysiology of sepsis involves activation of acid sphingomyelinase (SMPD1) with subsequent generation of the bioactive mediator ceramide. We herein evaluated the hypothesis that the enzyme exerts biological effects in endothelial stress response. Plasma-secreted sphingomyelinase activity, ceramide generation and lipid raft formation were measured in human microcirculatory endothelial cells (HMEC-1) stimulated with serum obtained from sepsis patients.

Differential inhibition of polymerase and strand-transfer activities of HIV-1 reverse transcriptase.

A new class of inhibitors of HIV-1 reverse transcriptase obtained by the systematic structural simplification of epicatechin and epigallocatechin gallates are also shown here to inhibit DNA-strand-transfer, a process critical to the completion of the HIV-1-RT reproduction and to recombination-associated mutation of the virus. Up to 80-fold selectivity for DNA-strand-transfer inhibition over polymerase inhibition was observed for a defined subset of these agents. Such specific DNA-strand-transfer inhibitors may have important therapeutic potential.

Correlating cell cycle with apoptosis in a cell line expressing a tandem green fluorescent protein substrate specific for group II caspases.

Background: We describe a rapid flow cytometric assay that correlates cell cycle with apoptotic cell death in a cell line expressing a tandem green fluorescent protein (GFP).

Methods: A Jurkat cell line was transfected with a gene construct coding for constitutive expression of a tandem GFP molecule carrying a consensus cleavage site (DEVD) for group II caspases (C-2-Y). Cells were treated with CD95 antibody (Ab), then incubated with annexin V-phycoerythrin (PE), propidium iodide (PI), and Hoechst 33342.

Simplified catechin-gallate inhibitors of HIV-1 reverse transcriptase.

Systematic simplification of the molecular structures of epicatechin gallate and epigallocatechin gallate to determine the minimum structural characteristics necessary for HIV-1 reverse transcriptase inhibition in vitro resulted in several compounds that strongly inhibited the native as well as the A17 double mutant (K103N Y181C) enzyme, which is normally insensitive to most known nonnucleoside inhibitors.

4-Hydroxy-5,6-dihydropyrones as inhibitors of HIV protease: the effect of heterocyclic substituents at C-6 on antiviral potency and pharmacokinetic parameters.

Due largely to the emergence of multi-drug-resistant HIV strains, the development of new HIV protease inhibitors remains a high priority for the pharmaceutical industry. Toward this end, we previously identified a 4-hydroxy-5,6-dihydropyrone lead compound (CI-1029, 1) which possesses excellent activity against the protease enzyme, good antiviral efficacy in cellular assays, and promising bioavailability in several animal species. The search for a suitable back-up candidate centered on the replacement of the aniline moiety at C-6 with an appropriately substituted heterocyle.