Cytochemical observations in preleukemic states and remission of akute leukemia.

In preleukemia and in remission of acute leukemia abnormal mononuclear cells ("string of bead" cells) have been observed and characterized with cytochemical methods. These cells may be resistant to cytostatic therapy and may be characterized as a source of a newly developing leukemic blast cells. Preleukemia and leukemic remissions seem to be identical states. Based on the morphological and cytochemical parallelity of cells in CFU-c-enriched fractions of the bone marrow and the so called string of bead cells we consider these cells to be closely related to the human commited stem cell.