Proceedings: Activities of L-ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase in x-irradiated murine leukaemic lymphoblasts L5178Y-S during mitotic delay.

  • O. Rosiek
  • Published 1975 in British Journal of Cancer

Abstract

S OF PROFFERED PAPERS 761 Apparently non-exponential survival curves found in earlier work (Michael et al., Radiat. Res., 1973, 54, 239) have been shown to be caused by an effect of cell density upon radiosensitivity. This effect has been eliminated and we have been able to determine the decay kinetics of oxygen-dependent damage in Serratia marcescens more accurately. The observed kinetics are qualitatively in agreement with those predicted by the Alper and Howard-Flanders model (Alper, Radiat. Res., 1956, 5, 573; HowardFlanders and Moore, Radiat. Res., 1958, 9, 422) but quantitatively they do not match the first order decay indicated by the model. The simplest possibilities suggested by the present data are either that the oxygendependent damage decays by second order kinetics or that there are 2 types of damage decaying at differing rates. THE ROLE OF SHORT AND LONGLIVED RADIOLYTIC PRODUCTS IN RADIOSENSITIZATION BY IODINATED AROMATIC COMPOUNDS. G. SIMONE and M. QUINTILIANI, Laboratorio di Fotochimica e Radiazioni d'Alta Energia (CNR), Bologna. In addition to iothalamic acid, other iodinated radiological contrast media have been tested for radiosensitizing activity. They were diatrizoic acid, containing a single triiodinated benzene ring, and iodipamide, containing 2 such rings. The experimental results have shown that both compounds strongly enhance the lethal effect of radiation on E. coli B/r in oxic conditions and are essentially ineffective in anoxia. Buffered solutions of the above mentioned compounds develop a long-lasting radiation induced bactericidal activity when irradiated at pH lower than 6. The bactericidal products appear to be related to the release of molecular iodine from the irradiated compounds, and formed in a process requiring OH radicals and molecular oxygen. In radiosensitization occurring when bacterial cells are irradiated in the presence of iodine containing compounds, the short-lived intermediate products appear to play the predominant role. ACTIVITIES OF L-ORNITHINE DECARBOXYLASE AND S-ADENOSYL-L-METHIONINE DECARBOXYLASE IN X-IRRADIATED MURINE LEUKAEMIC LYMPHOBLASTS L5178Y-S DURING MITOTIC DELAY. 0. RoSIEK, Institute of Nuclear Research,

DOI: 10.1038/bjc.1975.322

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Cite this paper

@article{Rosiek1975ProceedingsAO, title={Proceedings: Activities of L-ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase in x-irradiated murine leukaemic lymphoblasts L5178Y-S during mitotic delay.}, author={O. Rosiek}, journal={British Journal of Cancer}, year={1975}, volume={32}, pages={761 - 761} }