The effect of cryopreservation on committed stem cells (CFU-c's) in humans

The effects of different sources of colony-stimulating factor (CSF) and of cryopreservation have been studied on committed stem cells (CFU-c's) in bone marrow aspirates from patients with nonhematological ailments, acute leukemia (AL) in remission, and solid tumors, and in peripheral blood from patients with chronic myeloid leukemia (CML).Results showed significant effects due to the source of CSF and to freezing, colony scores being reduced on human placental-conditioned medium (HPCM) after freezing, whereas they remained the same or were increased on peripheral leukocyte underlayers (PBU). An analysis of the differential morphology of the CFU-c's showed that the ratio of eosinophil to polymor-phonuclear colonies was significantly lower on HPCM and after freezing on both sources of CSF.