Portal de Periódicos da CAPES

X. Modification of Radiation Damage After Exposure to X Rays

1954; Wiley; Volume: 27; Issue: 314 Linguagem: Inglês

10.1259/0007-1285-27-314-117

1748-880X

Alexander Hollaender, G. E. Stapleton,

Effects of Radiation Exposure

A Discussion of radiation “after-effects” in contrast to “direct” radiation effects appears to be, at first sight, a contradiction in terms, because observations are usually made, not during the process of irradiation, but at some time afterwards. For the purpose of this dicussion, after-effects will be designated as those which are subject to modification by treatment after the actual process of the irradiation has been completed. The previous speakers in this symposium have emphasised the effect of oxygen removal and treatment with chemicals, both of which affect radiosensitivity only when given immediately before or during exposure to X rays. Of the several ways of counteracting radiation damage by treatment after exposure, one of the most interesting is the method developed by Jacobson, University of Chicago (Jacobson, Marks, Robson, Gaston and Zirkle, 1949), who reported first that he was able to increase the LD50 for mice from 600 to over 1000 r by shielding the spleen with lead during X irradiation. He later reported that irradiated mice were able to recover to a considerable degree from X-ray damage if the spleen from a non-irradiated mouse was transplanted into an irradiated animal. He was then able to demonstrate a recovery if ground spleen tissue from a non-irradiated mouse was injected into an irradiated animal. Very similar results have been obtained by Lorenz (1951) and co-workers using bone marrow injections from non-irradiated mice. No cell-free extract has been reported to effect radiation recovery.