-~3methods of analyses. A research group at Massachusetts Insti
of Technology has been actively engaged in improving instrume
and methodology for determining very low amounts of radium an
mesothorium in tissue.
Since these studies are carried out
human patients, who have, unknowingly, ingested varying amou
mesothorium and radium over a period of years, the assembly
has been extremely difficult.
dependence has been laid upon analytical data from tissue s
of cadavers or from teeth of persons known to have ingested
amounts of radium and mesothorium, (For example, workers in
self-luminous dial industry.) One method presently under st
sists simply of imbedding in photographic emulsions a known
of tissue containing radioisotopes under observation.
the alpha particles on the photoplate as the radioisotopes d@cay to
Stable lead,
I+ is believed this method has a distinct ad
over the usual analytical methods dne to its sensitivity at
concentrations of radioisotopes.
Radiation Injury and Possible Subcarcinogenic Effects.
(UNCLASSIFIED)
In the Department of Oncology of the Chicago Medical
School, it has been demonstrated that mice, following local subcarcinogenic doses of beta irradiations of 800 reps to the ski >» followed
by repeated application of croton oil, will develop latent unOT
changes. Plaques of thallium 20 were used to provide the gource of
beta radiation. To gain a better understanding and control of both
radiation injury and possible subcarcinogenic effects, this group is
now concerned with the tumor changes induced in relation to the area
exposed,
Phagocytosis and Radioresistance.
(UNCLASSIFIED)
Inv PStigators
at the Atomic Energy Project, University of California at
bs Angeles,
have been studying the relation between the activity of th phagocytes
of the reticulo-endothelial system of rats and rabbits, an the resistance of these animals to radiation injury. The R-E sy
of special celis in liver, Spleen, lymph, and bone marrow
the capacity of engulfing and storing small particles. Ith
increased resistance to X-rays or to cobalt-60 gamma rays
In addition to the contribution of these findings to the
of the mechanism of natural radioresistance, the method m
experimental use in providing a means of increasing survi
irradiation so that the late effects may be studied.