[A count of osteogenic precursor cells in the bone marrow and their multiplication in cultures].

The progeny of clonogenic stromal medullary fibroblasts from rabbits was cultivated by repeated passage. As a result of several passages the number of cells under consideration could be raised hundreds of thousand times as compared with the initial cell quantity. The strains of stromal medullary fibroblasts were found to have osteogenic properties; during reverse transplantation to the body they formed osseous tissue, creating the medullary organs. It was shown that during cultivation, the amount of osteogenic units in a cell culture dramatically rose, i. e. the osteogenic precursor cells multiplied and were self-maintained. According to all these signs the clonogenic stromal cells of the bone marrow can be regarded as stem osteogenic cells.