[Ultrastructure of bone marrow stroma and endosteum in children with acute leukemia].

Ultrastructural peculiarities of stromal elements from bone marrow and endosteum in 28 children with acute leukaemia during clinical and hematological exacerbations are presented. Investigations are conducted before chemotherapy. Changes in ultrastructure of all stromal components are revealed. Of special significance are the data on variations of reticular cells and rough desorganization of fibrillar structures. Disturbances in intercellular contacts between hemopoietic cells and stromal elements are detected.