Quantitative Measurement of Hematopoietic Cells of the Marrow1

Absence of Late Radiation Effects on Bone Marrow Stem Cells

“…The total number of nucleated cells in the femurs of the irradiated mice was measured by the 59 Fe method of Donohue, Gabrio and Finch (1958), as previously described by Coggle and Proukakis (1970) The proportion of CFU-S in DNA synthesis was assayed using the tritiated thymidine suicide method of Becker, McCulloch, Siminovitch and Till (1965), and involved incubation of a suspension of marrow cells for 20 min at 37°C with tritiated thymidine (spec . act .…”

On the in vivo action of erythropoietin: a quantitative analysis

“…Total narrow cellularity was determined from the quantitative relationship, established through the use of 'Fe as a marrow label, between a counted femoral aliquot and the total marrow (10). 1 1ACi of radioiron was bound to fresh plasma and injected intravenously.…”

Megakaryocyte quantitation

“…Donohue, Reiff, Hanson, Betson, and Finch (12) observed cell-free radioactivity in the suspension preparations, and since they ascribed this radioactivity to red cell destruction they inserted an appropriate correction in their calculations of cell numbers. (10) cell suspension Harrison (11) 59Fe-dilution, 3.0 § cell suspension Present report 59Fe-dilution, Harrison (11) on the other hand, contended that the cell-free radioactivity represented loss of cytoplasm but not of nuclei from red cell precursors; he, therefore, made no such correction. There is no loss of cytoplasm when tissue is sectioned; thus, the close agreement of our data with those obtained by Harrison supports his contention (Table VII).…”

“…The hucounting); e = number of nucleated red cells in a single man nucleated red cell: megakaryocyte ratio was marrow section; a = activity of "Fe in the same section; 10 Assuming a total nucleated cell number in rats of A. = activity of 'Fe in the entire spleen; and Ab = ac-about 9 X 109 cells/kg, or about 1250 megakaryocytes/106 tivity of "9Fe in the entire bone marrow.…”