Activation of Prn-p gene and stable transfection of Prn-p cDNA in leukemia MEL and neuroblastoma N2a cells increased production of PrP(C) but not prevented DNA fragmentation initiated by serum deprivation.

Prion protein (PrP(C)) via its isoform PrP(SC) is involved in the pathogenesis of transmissible spongiform encephalopathies (TSEs). We observed that murine erythroleukemia (MEL) cells arrested in phase G(1) undergo transcriptional activation of Prn-p gene. Here, we explored the potential role of activation of Prn-p gene and cytosolic accumulation of PrP(C) in growth arrest, differentiation, and apoptotic DNA fragmentation by stably transfecting MEL and N2a cells with Prn-p cDNA.

In vitro assessment of cytotoxicity of resin-based dental restorative materials on WEHI 13 var fibroblasts.

Purpose: The aim of this study was to assess the cytotoxicity of 4 resin composites' eluates on WEHI 13 Var fibroblasts as they aged in a biologic medium.

Materials And Methods: Cytotoxicity was determined by counting the number of viable cells by trypan blue exclusion. Morphologic changes attributable to cytotoxicity were observed by May-Grunwald-Giemsa cytologic staining and microscopic examination.