Sublethal damage in cells of the mouse gut after mixed treatment with X rays and fast neutrons

Abstract
Irradiations from the 2 beams were given within minutes or at most a few h of each other when recovery from sublethal damage was not always complete. Cells surviving the 1st dose of radiation had accumulated the same amount of recoverable sublethal damage regardless of whether that 1st dose was with X-rays or neutrons. The rate at which the sublethal damage was shed was the same after X-ray and neutrons. There was less sparing of damage by fractionation of neutron dose compared with fractionation of X-ray dose not because there was less recovery from sublethal damage after neutrons but because there was relatively more lethal damage; the recovery from any sublethal damage was the same as if it were from X-rays. If X-rays and neutron doses were separated by times long enough to allow the full repair of sublethal injury, then the combined effect was simply additive.