THE ACTIVITY OF NUCLEOLAR ORGANIZER REGIO NS IN MEGAKARYOCYTES FROM PATIENTS WITH LEUKEMIA

The activity of nucleolar organizer regions (NOR) in megakaryocytes (M K) from 21 patients with acute lymphoblastic leukemia (ALL), 35 patien ts with acute nonlymphooblastic leukemia (ANLL) and 12 patients with b last crisis of chronic myeloid leukemia (BC CML) were studied by silve r staining. The control group consisted of 12 donors. The activity of NOR in the whole population of MK and in groups of MK with 1-3, 4-6, 7 and over lobules per nucleus (MK 1, 2 and 3 class, respectively) were taken into account. The activity of NOR in the group of first class M K from patients with acute leukemia (ALL and ANLL) was detected low. O n the contrary, it was high in the group of third-class MK of those pa tients, as compared to the control. The activity of NOR in MK of BC CM L patients was significantly lower as compared both to the control and to patients with acute leukemia. The cause of changing the functional state of MK in varying hematology disease has been discussed.