[Cellular composition of hemopoietic tissue of the liver and spleen in the human fetus].

Cell composition has been studied in hepatic reprints of 76 human fetuses between 6-27 weeks of development. Erythropoiesis predominates during the whole period of hepatic hemopoiesis. During 6-7 weeks primary erythroblasts make 1/4 of all erythroid cells, and by the 22d-27th weeks their content does not even reach 1.5%. Content of neutrophilic leucocytes is 1-1.5%. Nondifferentiated blast cells make 2.9 +/- 0.5-1 +/- 0.1%. Their greatest amount is observed between 6-8 and 18 and more weeks. The cell composition of the fetal spleen has been studied in 10 fetuses 19-25-week-old. Lymphoid forms make 85%, of all cells of the organ's hemopoietic tissue, of them 2.9 +/- 0.4% are lymphoblasts, 0.3 +/- 0.1%--nondifferentiated blasts. The investigations studying colonyforming properties of the hematopoietic cells confirmed that the highest content of myeloid precursers in the fetal liver and spleen is noted between 9-21 weeks of age. Therefore, it is possible to expect the greatest effect of these organs' transplantation during this time.