title: Growth patterns, cell composition, and mitotic activity of granulocytic aggregates developing in methyl cellulose from human normal marrow cells.
abstract: Marrow cells from five normal healthy subjects were cultured in methyl cellulose with and without leucocyte conditioned medium. Cultures were examined daily from day 3 to day 14 for the number of granulocytic aggregates and for their cell composition and mitotic activity. Aggregates of different size (small and large clusters, small and large colonies) displayed four distinct and characteristic patterns of growth. Unidentifiable blast cells were very rare throughout culture. The average proportion of recognizable granulocyte precursors (promyelocytes and myelocytes) (PMC + MC) declined during culture from 60% to 34%. There was a negative correlation between the size of the aggregates and their PMC + MC content, but on any day of culture some aggregates consisted mainly or uniquely of PMC + MC, while some others consisted mainly or uniquely of non-proliferating granulocytes. The mitotic index of PMC + MC was much higher than the one previously determined in vivo, and was significantly higher in large colonies than in other aggregates. These results are consistent with the recent demonstration of different CFU-C (sub)populations. It is suggested that differentiation of the aggregates according to their size and kinetics, coupled with cytological examination, can provide a more refined assessment of the assay, which could be useful for further comparison of normal, abnormal, and leukaemic granulocytopoiesis.
mesh_terms: D000328:Adult; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003470:Culture Media; D006098:Granulocytes / Q000166:cytology* / Q000502:physiology; D006410:Hematopoiesis; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008747:Methylcellulose; D008940:Mitotic Index; D013997:Time Factors
chemical_list: D003470:Culture Media; D008747:Methylcellulose