Tissue Culture of Primitive Human Myeloid Cells for the Study of Cellular Proliferation : Preliminary report on a growth inhibitor in the heated serum of two patients with chronic myelogenous leukemia (CML) following splenic irradiation

Sera from two patients with chronic myelogenous leukemia obtained within one hour after irradiation of the spleen inhibited the growth of a stable cell line derived from the blood of a patient with acute myelogenous leukemia. This inhibitory factor was stable in vitro for one half hour at 55 C. and for 3 days at -80 C.

Serum from a patient with metastatic carcinoma of the breast following thoracic irradiation did not have a similar effect.