Radiobiologiia最新文献

Rats exposed to ionizing radiation (0.5 Gy) and short-term immobilization stress displayed CNS activation accompanied by diminution of working memory when tested in radial maze. Irradiation, as compared to stress, caused exploratory activity inhibition that led to certain automatism in task fulfillment. Exposure to emotional stress after irradiation modified significantly rat performance causing CNS inhibition and long-term memory decline.

A thymocyte plasma membrane suspension was irradiated with a dose of 5 +/- 10(4) Gy. An increase in the rate of lipid peroxidation and a change in the phospholipid composition of membranes were revealed. The alteration of the plasma membrane structure was characterized by a change in the membrane charge and a decrease in the lipid viscosity.

Dogs were exposed to X radiation at a dose of 15 Gy; part of them received a complex treatment. The morphological studies of internal organs of control dogs were made before death (on days 4 to 15 after irradiation). The treated dogs were killed 0.5-2 years following irradiation. Hemodynamics normalization was noted in 1.5-2 years in the liver, brain cortex, adrenals, insular tissue of the pancreas, and lymph nodes.

Specific 2-propynylamine inhibitors of monoamine oxidase (MAO) pargyline and especially chlorgyline, a selective inhibitor of MAO A (but not deprenyl, a selective inhibitor of MAO B) increase the radioprotective effect of small doses of O-methyltyramine and phenylephrine and do not change the efficacy of large doses. This is consistent with the receptor theory of the mechanism of protective action of amines.

The method of flow cytofluorimetry was used to study some population characteristics of bone marrow cells of control and irradiated rats. The simultaneous recording of cellularity and distribution of myelokaryocytes among the cell cycle phases was shown to give reliable results for determining the extent to which the organism was exposed at early times following irradiation.

Thymocytes were irradiated with doses of 4 to 10(3) Gy. The binding of 1-anilino-naphthalene-8-sulphonate and Ca2+ to plasma membranes; viscosity and lipid peroxidation; Stern-Folmer constant; and the number of SH-groups of membrane proteins were determined. The structural changes in plasma membranes after irradiation of thymocytes were found to be cooperative.

Pine assimilative tissue was studied in the region of Chernobyl Power Plant accident the 1986-1988. With radiation doses of 8-11 Gy pine needle was viable inspite of the significant structural changes in cell organelles. With doses of 20-25 Gy the inner structure of mesophyll cells was impaired. High radiosensitivity was displayed by mitochondria and chloroplasts where irreversible destruction of membrane systems occurred.

The influence of X-radiation on production of interleukin-6 (IL-6) and alpha-tumor necrosis factor (TNF) has been investigated. Irradiation with doses of 45, 90 and 900 cGy was shown to increase considerably TNF and IL-6 production both in intact mononuclear cultures of human peripheral blood and in cultures stimulated by phytohemagglutinin. In addition to an absolute increase in the production, the stimulatory effect was manifested by earlier accumulation of IL-6 and TNF activities in supernatant fractions of the cultures under study.

The sensitivity to gamma- and secondary proton (70 GeV) radiation was studied in fibroblast cell culture of Chinese hamster and NIH 3T3 mice and, with respect to survival rate, in lymphoma strains L5178 V-S and L5178 V-R. It was shown that RBE was high for radiosensitive cultures and that the major role in the final biological effect was played by the mode of the postirradiation processes rather than by the peculiarities of the primary injury.