Radiats Biol Radioecol
February 2001
The breathing of gas mixtures containing 8-9% O2 during irradiation of tumors has been tested at several cancer clinics (in Russia and abroad) with the purpose of decreasing the morbidity of normal issues, thus providing the possibility to increase the dose of radiation. Previous experiments have demonstrated a broad spectrum of dose modification factors (DMF) for different normal tissues as well as for different transplanted tumors, with in general larger protection of normal tissues. The present study was designed to assess the radioprotective effect for mouse kidney of breathing a gas mixture containing 8% O2 by morphometry of histological specimens.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
May 1994
Purpose: Glutathione (GSH) was found to occur in relatively high concentrations in melanoma cells. The purpose of this study was to test the possible cytotoxic effects of an artificial decrease of the elevated GSH level.
Methods And Materials: The tests were made in vitro and in vivo.
The effect of gas hypoxic mixture, containing 8% of O2 (GHM-8), on the ability of cell precursors of haemopoietic stroma (which form colonies (clones) of fibroblasts (CFU-F) in a culture, and are present in the bone marrow of adult rats) to repair potentially lethal and sublethal radiation damages has been investigated. The recovery of CFU-F from potentially lethal damages, that was studied after their delayed survival in a culture following irradiation of animals, proceeds at nearly the same rate in cells irradiated both in the air and in hypoxic conditions (GHM-8). Fractionated irradiation reduces the radioprotective effect of GHM-8 for CFU-F, particularly for the radioresistant subpopulation; the ability of CFU-F to recover from sublethal radiation damages decreases.
View Article and Find Full Text PDFThe ability of cell precursors of the haemopoietic stroma (CFU-F), that are present in the bone marrow of adult rats, to recover from potentially lethal and sublethal radiation damages has been investigated. The highest reparability, with respect to potentially lethal damages, is displayed by the most radioresistant CFU-F population, that forms loose colonies (clones) in a culture; the slope of the dose-response curve, not the extrapolation number, changes, and heterogeneity of the CFU-F population is observed. The results obtained confirm the presence of heterogeneity in the population of CFU-F, that was revealed in studying their radiosensitivity by the formation of dense and loose fibroblast colonies in a culture.
View Article and Find Full Text PDF