title: Studies on the presence and possible oscillations of granulocytic progenitor cells (CFU-C) in human blood.
abstract: The presence of CFU-C in the peripheral blood of 3 healthy volunteers was monitored over a period of 70 d. Blood samples were taken 3 times a week. Mononuclear cells (MNC) were separated from blood leucocytes by dextran sedimentation and the iron ingestion method. After cryopreservation the cells were cultured in soft agar. One sample of mononuclear cells was cultured using a leucocyte feeder layer as a source of colony stimulating activity (CSA) and another sample using human placental conditioned medium as CSA. In cultures using a leucocyte feeder layer, the average number of CFU-C was 29, 43, 118 per ml blood. No systematic oscillations were observed. When human placental conditioned medium was used the average number of CFU-C was 255, 125, 222 per ml blood, respectively. Significant oscillations with periods of 23, 19 and 25 d were observed.
mesh_terms: D000328:Adult; D002469:Cell Separation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007958:Leukocyte Count; D008214:Lymphocytes / Q000166:cytology; D008264:Macrophages / Q000166:cytology; D008297:Male; D009000:Monocytes / Q000166:cytology