[en] The lack of a reliable, and preferably mechanistic, method to predict radiosensitivity parameters impedes ongoing efforts to develop biologically optimal radiation therapy treatments. The development and application of predictive assays is also hampered by the apparent lack of a systematic relationship between in vitro and in vivo intrinsic radiosensitivity. As a first step towards better quantifying the relationship between in vitro and in vivo radiosensitivity, we re-analyzed a large number of datasets using the Linear Quadratic (LQ) survival model with and without the generalized Lea-Catcheside dose protraction factor G. With G = 1 (no correction for dose rate effects), the analysis of cell survival data for acute irradiation conditions (dose rate > 45 Gy h^-1) yields α/β ratios of 8.17 and 8.33 Gy for CHO 10B2 and C3H 10T1/2 cells, respectively. When the dose protraction factor is computed using a 2 hour repair half-time, reanalysis of these same datasets gives an α/βof 7.2 Gy for CHO 10B2 cells and 7.6 Gy for C3H 10T1/2 cells. For repair half-times from 0.2 to 5 h (G ∼ 0.65-0.99), α/β ranges from 1.8 to 7.8 Gy for CHO 10B2 cells and from 3.2 to 8.0 Gy for C3H 10T1/2 cells. Global fits to low, intermediate, and high-dose-rate survival data indicate that the optimal α/β is 1.96 and 7.61 Gy for CHO 10B2 and C3H 10T1/2 cells, respectively. These studies demonstrate that the α/β cannot be reliably estimated from survival data for acute irradiation conditions. To better quantify intrinsic radiosensitivity, both low and high dose rate survival data are needed. Regardless, the analysis of cell survival data should always use the LQ with corrections for dose rate effects. A range of repair half-times should also be used to help estimate uncertainties in α , β, and the α/β ratio

[en] The radioprotective properties of selenium-comprising chicory phytocomposites (SECP) have been studied in a series of animal experiments. The prospectively of selenium as a basic material for food supplements and functional nutrition products for protection against acute and prolonged irradiation is demonstrated. The study demonstrates the radioprotective effect of the SECPE at both acute and prolonged irradiation exposure. This effect is based on the high biological activity of the SECPE which stimulates, regulates, and restores the psychoneuroimmune system and the non-specific resistance mechanisms. In our opinion, the SECPE radioprotective effect is most expressed at acute irradiation exposure. Based on the SECPE, we have elaborated a dietary food supplement with biological activity “Selenium-S”, which is promising both being used per se and for functional product development with the purpose of psychoneuroimmune regulation improvement including cases of radiation damage and requires further investigation of use peculiarities.

[en] Current information is presented in the paper concerning the biological indication of radiation effects within a wide range of doses. The radiobiological phenomena that lay the basis for the development of methods of diagnosis of radiation injury are discussed. A new classification of biological indicators of radiation affection based on the principles of pathogenesis is proposed. The informativeness of the diagnosis methods available is evaluated and the directions, which the search for new biological indications of radiation effect should follow, are outlined

[en] A randomized study was performed to evaluate 5 years results of combined treatment of patients with ray-resistant cancer of large intestine in correlation with post-radial changes in dissected tumours. Experiments were carried out in groups of patients exposed to different preoperative ray doses with or without antioxidant supply. Summer local dose on the tumour was 20 Gy (single dose was 5 Gy) or 30 Gy (single dose was 6 Gy). The data revealed some histological or histochemical post-radial differences in dissected tumors, but these changes were not connected with radiation dose or antioxidant supply. It was concluded that post-therapeutic changes in tumor after radial therapy could not be used for assessment of degree of risk of metastasis

[en] Short communications

[en] Short communication

[en] Plastic scintillators form a ubiquitous component of modern particle physics detectors. With the planned construction of a new generation of high luminosity (intensity), high energy, colliding beam accelerators, it is known that unprecedented high levels of radiation will be present in the experimental halls. Some components of the detector (specifically those utilizing scintillator) will have to endure annual doses of 10⁴ to 10⁵ Gy or more. Standard scintillators will not survive such conditions. This is a review of research started three years ago with the goal of developing plastic scintillators appropriate to such an environment

[en] Mathematical models of erythropoiesis and granulocytopoiesis dynamics in mammals exposed to acute radiation have been developed to simulate the abortive rise in the concentrations of bone marrow cells of erythroid and granulocytic series during the postirradiation recovery of erythropoietic and granulocytopoietic systems

[en] Short communication

[en] Taxol is an investigational antineoplastic agent which acts by stabilizing microtubules, thereby preventing normal mitosis. It is believed to block cells in the G₂/M phase of the cell cycle. The drug is a natural product isolated from the yew, Taxus brevifolia. We have used a cell line derived from human cervical carcinoma to investigate the combination of Taxol with high and low dose rate ¹³⁷Cs irradiation. An additive effect for Taxol plus radiation was observed; supra-additivity or synergism is not suggested by our data. In the cell line studies, drug concentrations that accumulate cells to some degree in the G₂/M phase of the cycle lead to cell cycle. In the clinic, Taxol shows promise both as a chemotherapeutic agent and as a possible adjunct to radiation. The present work demonstrates the need for further studies of Taxol plus radiation with a variety of human cell lines of normal and malignant origin. (author). 11 refs., 6 figs