Fig. 9. Effects of combining GM-CSF and cytostatic agents on normal hematopoiesis. Bone marrow mononuclear cells from normal donors were treated for 120 h in the absence (Control) or presence of hydroxyurea (HU, 100 µg/ml), phenylbutyrate (PB, 1.5 mM), or bryostatin-1 (Bryo, 10-8 M) with or without GM-CSF (200 units/ml) and then washed and plated in methylcellulose. Results are the means of three separate experiments; bars, SE. Ps are as determined by ANOVA for the comparison of all treatment groups.