Valproate induced changes in cell number, apoptosis, and viral production in BCBL-1 cells. BCBL-1 cells were grown in the absence or presence of valproate (0.6 mM; ▪) or butyrate (0.3 or 0.6 mM; ▴) for the indicated times. ♦ indicates control cells. (A) The total number of cells at each time point in the absence and presence of valproate or butyrate. (B) The percentage of cells that were apoptotic at each time point as assessed by flow cytometric analysis of TUNEL-positive cells. (C) The relative amount of infectious virus in conditioned medium at each time point based on β-galactosidase produced by the T1H6 reporter cell line. Values shown in panels A and C are the mean ± SD from 3 and 6 replicate determinations, respectively.