Structural and functional state of the bone marrow during its in vitro interaction with ferromagnetic nanoparticles.

Hemopoietic islets, associations of stromal (macrophages, fibroblasts) and blood (including stem) cells, are structural and functional units of the bone marrow. We studied cellular and molecular processes developing following short-term (1 h) contact of hemopoietic islets with ferromagnetic nanoparticles in a multicellular system of the bone marrow in vitro. It was established that nanodispersions of magnetite (Fe(3)O(4), mean particle diameter 18 nm) and iron coated with carbon (Fe(C), particle diameter 5-10 nm) in a dose of 3 mg/liter had a minor effect on processes of necrotic and apoptotic cell death.

Molecular mechanisms of the effect of interleukin-2 on apoptosis of blood lymphocytes.

The effects of recombinant IL-2 on apoptosis of lymphocytes of healthy donors were studied in in vitro experiments. It was shown that the inductive and inhibitory effects of IL-2 on apoptotic process depend on the dose of the cytokine and cell microenvironmental conditions. Culturing of lymphocytes with recombinant IL-2 increases the percent of cells with reduced transmembrane potential, reduces the content of intracellular proteins Bcl-2, Bcl-X(L) and и Bax, and increases the level of Bad.

Role of reactive oxygen species and Bcl-2 family proteins in TNF-α-induced apoptosis of lymphocytes.

We studied the in vitro apoptosis-inducing effect of recombinant TNF-α (rTNF-α) on blood lymphocytes from healthy donors. rTNF-α-induced apoptosis was accompanied by an increase in the number of cells with low mitochondrial transmembrane potential, increased intracellular content of reactive oxygen species, reduced content of Bcl-2, Bcl-xL, and Bax proteins, and elevated Bad content. The molecular mechanisms of these changes are discussed.

Role of NF-kB, p53, and p21 in the regulation of TNF-α mediated apoptosis of lymphocytes.

The effect of recombinant TNF-α on programmed death of donor lymphocytes was studied in vitro. The proapoptotic effect of this cytokine is realized through transcription factors and cell cycle inhibitors. Incubation of lymphocytes with recombinant TNF-α revealed increased levels of NF-kB and p21 and reducted content of nonphosphorylated p53.

[Formation of probabilistic structure of motor behavior in bottlenose dolphins in captivity].

A probabilistic structure of the motor behavior was analyzed in dolphin calves Tursiops truncatus in the prenatal period and adult dolphins in an oceanarium. Ethograms were recorded and subjected to a computer analysis. Ranking probabilities of transitions between behavioral acts revealed a highly determined sequence of operations underlying the newborn dolphins' behavior.