status: Published
We have found that novel pyridine oxide derivatives are inhibitors of a wide range of human immunodeficiency virus (HIV) type 1 (HIV-1) and HIV-2 strains in CEM cell cultures. Some of the compounds showed inhibitory activities against recombinant HIV-1 reverse transcriptase (RT), whereas others were totally inactive against this viral protein in vitro. Partial retention of anti-HIV-1 activity against virus strains that contain a variety of mutations characteristic of those for resistance to nonnucleoside RT inhibitors and a lack of inhibitory activity against recombinant HIV-2 RT suggested that these pyridine oxide derivatives possess a mode of antiviral action independent from HIV RT inhibition. Time-of-addition experiments revealed that these pyridine oxide derivatives interact at a postintegration step in the replication cycle of HIV. Furthermore, it was shown that these compounds are active not only in acutely HIV-1-infected cells but also in chronically HIV-infected cells. A dose-dependent inhibition of virus particle release and viral protein expression was observed upon exposure to the pyridine oxide derivatives. Finally, inhibition of HIV-1 long terminal repeat-mediated green fluorescence protein expression in quantitative transactivation bioassays indicated that the additional target of action of the pyridine oxide derivatives may be located at the level of HIV gene expression.
Viel hilft viel – dies galt bislang bei Modulatoren der P-Glycoprotein-vermittelten Mehrfachresistenz in der Krebstherapie für die Zahl der Wasserstoffbrücken im Hinblick auf eine ausgeprägte inhibitorische Aktivität. Diese Ansicht wird mit einer neuen Klasse von Inhibitoren vom Hydroxymethyl-3,9-diazatetraasteran-Typ 1, die eine symmetrische Struktur aufweisen, erstmals infrage gestellt.
Abstract In our attempts to develop nucleoside analogues with selective antiviral activity we have envisaged the following targets : viral DNA polymerase (whether or not via viral dThd kinase), reverse transcriptase, AdoHcy hydrolase, dTMP synthetase, OMP decarboxylase and CTP synthetase
This work analyses the effects of electrical conductivities of dielectric and cobalt amount on output parameters such as metal removal rate and the surface roughness value of cemented carbides cut by wire electrical discharge machining(W-EDM). Especially, the cracking behaviour of W-EDM machined surface and optimal machining condition of three kinds of cemented carbides, which have different chemical composition of tungsten carbide and cobalt are also tested. Experimental result shows that increases in cobalt content and electrical conductivity of the dielectric affect the metal removal rate and substantially worsen the final surface quality as a greater quantity of solidified metal deposits on the eroded surface.
No abstract is provided for this article.