[Nature of the silver staining and association of acrocentric chromosomes in normal and leukemic human cells].

Silver staining and acrocentric chromosome association (ACA) patterns were investigated in bone marrow cells as well as in peripheral blood cells (cultures with or without PHA) from 39 patients with chronic myelocytic leukemia (CML), including 20 cases being in blastic phase (BP CML), and 51 patients with acute leukemia (AL). Bone marrow cells and PHA-stimulated peripheral blood lymphocytes (from 10 and 17 healthy donors, respectively) were used as a control. The frequency of ACA in metaphases from bone marrow cells of all the above groups of patients was shown to be decreased compared to that in PHA-stimulated lymphocytes. Patients with BP CML and AL constituted the most heterogeneous groups although some of them demonstrated the highest ACA-frequency per cell. There is a pronounced correlation between Ag+-nucleolus organizer regions (NOR's) and the frequency of ACA. With the exception of CML, the correlation coefficients (0.83, 0.74, and 0.72) were highly significant for all the above groups (donors, BP CML, and AL patients, respectively). The distribution pattern of single chromosome pairs, according to their ACA frequency, differed with every individual studied, but it was similar in normal and leukemic cells of the same individual. From the above data a conclusion is made that the frequency of ACA may depend on the functional activity of the NOR's as well as on the cells type.