[The production of granulocyte colony-stimulating factor by stromal bone marrow populations].

Passaged bone marrow fibroblasts (PBMF) fail to maintain long-term hemopoiesis in culture unlike stromal adhesive layers of long-term culture of the bone marrow (LTCBM). What differs PBMF from LTCBM stromal cells in terms of the above ability we attempted to find out using immunocytochemical microscopy and flow cytometry. There were no differences as to protein production of the extracellular matrix, production of granulocytic-macrophagal colony-stimulating factor, stem cell factor, transforming growth factor beta, interleukin-1 beta and interleukin-6.

[Prognostication of the dose modifying factor in consecutive thermo-radiation exposure of yeast cells].

The dependence of dose modifying factor after the consecutive thermoradiation actions on dose rate and dose of ionizing radiation as well as on temperature and duration of its application was studied for yeast cells. The results obtained were described and interpreted by means of the mathematical model of synergism in accordance with which the synergism is expected to result from the additional lethal damage arising from the interaction of sublesions induced by both agents.

[A mathematical description of the synergism in the simultaneous cytotoxic action of chemical agents and hyperthermia].

Applicability of mathematical model to the description and prognosis of cytotoxicity of tris(1-aziridinyl)-phosphine sulfide (thio-TEPA) and cis-diamminedichloroplatinum (cis-DDP) at various temperatures was tested for the inactivation of clone-forming ability of hamster cells and murine fibrosarcoma. The model suggests that the synergistic interaction of chemical agent and hyperthermia may result from additional lethal damages arising from the interaction of sublesions induced by both the agents. The model allows a quantitative analysis of the combined action of the used agents and predicts the maximum value of the synergistic effect and the conditions under which this effect can be achieved.