dITP may be generated from dATP by a slow, nonenzymatic hydrolysis. While [H]dITP was degraded rapidly to [H]deoxyinosine by HeLa cell nuclear extracts, no net degradation of [H]dITP was observed in the presence of physiological concentrations of ATP, apparently because the extract contained deoxynucleoside diphosphate kinase activity that regenerated [H]dITP from [H]dIDP. Isolated HeLa cell nu...

Nucleosomes are multi-component macromolecular assemblies which present a formidable obstacle to enzymatic activities that require access to the DNA, e.g. DNA and RNA polymerases. The mechanism and pathway(s) by which nucleosomes disassemble to allow DNA access are not well understood. Here we present evidence from single molecule FRET experiments for a previously uncharacterized intermediate s...

Interleukin-1beta (IL-1beta) stimulates expression of the highly inducible enzyme cyclooxygenase-2 (COX-2) via activation of nuclear factor kappaB (NFkappaB), and consequently provokes prostaglandin E(2) (PGE(2)) synthesis, which induces inflammatory responses. In this study, the contribution of protein kinase C (PKC) to IL-1beta-induced PGE(2) synthesis in human gingival fibroblasts was invest...

Nanoparticles containing DNA complexed with the cationic polymer polyethylenimine are efficient vehicles to transduce DNA into cells and organisms. DNA/polyethylenimine nanoparticles (DNPs) also elicit rapid and systemic release of proinflammatory cytokines that promote antitumor immunity. In this study, we report that DNPs possess previously unrecognized immunomodulatory attributes due to rapi...

Polysaccharides and other cationic polymers have been recently used in pharmaceutical research and industry for their properties to control the release of antibiotics, DNA, proteins, peptide drugs or vaccines and have been also extensively studied as non viral DNA carriers for gene delivery and therapy. Among them, chitosan is one of the most used because it promotes long term release of incorp...