Effects of Decay of Incorporated H3-Thymidine on Bacteria

Abstract

The killing efficiency due to the decay of incorporated H(3)-thymidine in three mutants of E. coli strain 15: 15(T-), 15(T-L-), and 15(T-U-) has been determined. This efficiency is comparable to that previously determined by others for P(32) decay. The killing efficiency has been determined as a function of H(3)-thymidine specific activity, storage media and storage temperature. We have observed a latent killing effect that causes lethality under certain conditions. The kinetics of latent killing have been examined at several temperatures. Finally, mutation production induced by H(3)-thymidine decays was shown to occur. The results are consistent with the idea that inactivation and mutations may be caused by a process in the nuclear transmutation that is not associated with beta-particle ionization damage.

Solar-Flare Induced Increases in Sea-Level Cosmic Ray Intensities and Other Geophysical Phenomena in Relation to Multiple Sclerosis1

“…(Stenf & Fuerst, 1960;Person & Lewis, 1962). It should be noted that this biological effect of atomic transmutation is fundamentally different from the biological effect of ionizing radiation.…”

“…It should be noted that this biological effect of atomic transmutation is fundamentally different from the biological effect of ionizing radiation. (Stenf & Fuerst, 1960;Person & Lewis, 1962).…”

The Distribution of the Number of Postirradiation Cell Division

“…This possibility seems to be negligible, though it cannot be ruled out completely, because re-utilization was not demonstrated in experiments with bacteria. [29][30][31][32] (3) A third possibility is that the growth curves in Fig. 5 are not based on the generation time.…”

Macromolecular Synthesis in Newly Transformed Cells of Bacillus subtilis

“…Koch (13) concluded that this difference in efficiency of killing is due to the nearness of the tritium isotope to the DNA in the cell. The rate of death is also dependent upon the amount of tritium incorporated (1) and the storage temperature (23). Although the exact mechanism of tritium "suicide" is the subject of some controversy (30), nongrowing ceUs within a population which do not incorporate the tritiated compounds are resistant to suicide (17).…”