[Various activities of the nucleolus organizer region in normal and leukemic bone marrow cells: semiquantitative data and computer- assisted image analysis by silver staining].

A cytochemical technique with silver nitrate staining was used to study the nucleolar organizer activity in metaphase spread of bone marrow cells from 13 patients with acute lymphocytic leukemia (ALL), 11 patients with chronic myelogenous leukemia (CML), 7 patients with acute myelogenous leukemia (AML), and 4 normal persons. Additionally, computer-assisted image analysis was used to quantitate the amount of silver staining in interphase nuclei of bone marrow cells from 6 untreated ALL patients, 3 normal subjects and 1 bone-marrow-transplant recipient. The results obtained have indicated that the nucleolar organizer reactivity (NOR) is significantly lower in the control group than that in ALL patients. NOR activity level is significantly lower in both CML patients in chronic phase, and AML patients than in the ALL group, and is similar to that in the control group. When the data obtained for the interphase nuclei were compared with those obtained for the metaphase spread, a strong correlation was recorded between the fraction of bone-marrow metaphases stained positively with silver, the average number of silver-positive nucleolar organizer regions per metaphase, and the amount of silver staining in the interphase nuclei. Silver staining used for the detection of these disease-related differences in NOR activity can serve as a diagnostic procedure in evaluating human leukemias. The computer-assisted image analysis of bone marrow cell interphase nuclei would be useful for more accurate resolving biological and medical problems.