Late Myelosuppressive Action of Programmed Chemotherapy in Acute Lymphoblastic Leukemia in Children.

The capability of peripheral blood leukocytes and bone marrow cells to spontaneous apoptosis was studied in 36 children with ALL remission at various periods after polychemotherapy withdrawal. The enhancement of apoptotic activity has been revealed to be the universal mechanism of delayed effect of antileukemic chemotherapy for all the compartments of hemopoiesis, including granulocyte/macrophage precursors. The expression of this phenomenon is decreasing with the time period elapsed after treatment withdrawal.

Kinetics of Apoptosis of Peripheral Blood Leukocytes in Normal State and in Children Recovered from Acute Lymphoblastic Leukemia.

The original method is proposed for the study of apoptosis kinetics in cell populations by determination of apoptotic cell accumulation during the day's incubation in serum free medium. We have studied the features of this process for peripheral blood granulocytes and lymphocytes from healthy children. High sensitivity of the proposed method has been shown for the estimation of apoptosis, taking for illustration the analysis of delayed chemotherapy influence on blood cells in children, recovered from acute limphoblastic leukemia (ALL).

Intercellular Interactions in the System of Hemopoietic Stem Cells.

Last years there are some reports about influence of erythron cells and immune system. It especially concerns with immunomodulation effect of cells of erythroid series and main humoral erythropoiesis regulator - erythropoietin. Much is known about the influence of cytokines of lymphoid and macrophagal origin on hemopoiesis, and in particular on erythroid compartment, and on functional activity of polypotent hematopoietic stem cell (PHSC).

Spatial localization of chromosome-nuclear envelope interaction sites.

In the interphase nucleus chromosomes are tightly associated with the nuclear envelope (NE) through special granular chromatin particles termed anchorosomes. It remains unclear whether anchorosomes represent constant nuclear structures, persisting throughout the cell cycle, or they appear only in the interphase during the formation of contacts between the chromosomes and NE. In other words, whether specific NE interaction sites do exist in chromosomes or any region can form anchorosome.