[Quantitative determination of human bone marrow proliferation kinetics during three culture days]

In order to obtaon of human bone marrow cells, fresh bioptic material was homogenized and the cell suspensions were incubated for 72 hs in a fluid medium. After 24, 48 and 72 hs of incubation the total cell number of the culture was determined. At the same time differential counts of stained smears were performed. Both, erythrocytopoiesis and granulocytopoiesis showed regeneration, maturation, and an absolute increase of the number of precursors and of mature cells. The quantitative data obtained in vitro during 24 hs correspond with our data of kinetics obtained by observed mitotic duration and cell differential countings in vivo. However, after a longer cultivation time we found a diminution of divisible precursors, and an increase of mature erythroblasts as well as an excessibe survival of the PMNs.