Morphologic changes in culture induced by elastase.

Cytospin preparations of CD34⁺ cells cultured with 25 ng/mL G-CSF, GM-CSF, and SCF and with or without 1 μg/mL elastase on days 3, 6, and 8. (A-B) Day 3: no differences between control and elastase-treated cells. (C-D) Day 6: widespread apoptosis in differentiating elastase-treated CD34⁺ cells. (E-F) Day 8: mature neutrophils observed almost exclusively in control cultures. Original magnification, × 400.