[Methodological approaches to the analysis of postradiation impairment of lympho- and hematopoiesis].

: Human intrathymic precursors are characterized by mitogenic reaction on thymic hormone, lacking the cortical and medullar thymic membrane markers (CD3, CD4 and/or CD8) and expressing of the common T-cell CD7 and CD5 antigens. Fraction 1.062 g/cm3 of peripheral white blood cells contains cells with analogous characteristics. The cell fraction of blood from men participated in amelioration after the Chernobyl accident is enriched with hemopoietic precursors (CD4+), pre-T-cells, reacting to thymosin (CD5+CD3-), and CD3+CD4-CD8- T-cells in a greater extent than the cell fraction from donors blood. Defects of T-cell and hemopoietic differentiation in children migrated from the Chernobyl area to Moscow Region were more substantial than in "ameliorators" and correlated with drop of thymic serum activity level. Research substantiates the approach to analysis of radiation-induced defects in early stages of lympho- and hemopoiesis.