EIGH'I' FIGTJRESIn the search for a suitable inethod of determining quantitatively the effects on niamrrialiaii tissue of sublethal doses of ionizing radiation, the following study of the mitotic indices of various mouse tissues following whole body irradiation was undertaken. I t was hoped that by finding quantitative changes in the mitotic index of various tissues that it would be possible to use these clianges as a measure of the relative effects of different types and different energies of ionizing radiation. The response of mitotic activity of 4 tissues was determined at intervals after exposures of groups of animals to doses ranging from 5 to 325 roentgens of 250KV x-rays. The adrenal gland, lymph node, jejuiium and epidermis were selected for this study because of their normally high mitotic activity and because of the simplicity of their structure which lends itself t o the development of qnantitativP methods of counting mitoses. The effect on the epidermis at the 35 roentgen and 32.5 roentgen dosage levels has been previously reported (Knowlton, Hempelrnann and Hoffman, '48)
1. The refractive neutral red staining particles seen in unstained or supravitally stained lymphocytes have the following properties: They are birefringent and show a polarization cross. Their refractive index is 1.45 to 1.48. They are soluble in fat solvents, in cold alcohol and in strong but not weak acid or base. They stain with lipid stains and basic dyes and are increased in number by the action of neutral red on supravital preparations of blood cells. 2. These properties are interpreted as indicating that the particles seen in human lymphocytes are composed of lipid material. It is probable that much of the fat is of the polar-apolar type, possibly phospholipid in nature. 3. The refractive particles are believed to be the counterparts in human lymphocytes of the phospholipid-containing droplets which occur in somatic cells of other mammalian tissue. 4. The significance of the increase in numbers of these droplets under certain conditions and their relationship to the Golgi apparatus are discussed.
The development of the atomic energy program has resulted in a large increase in the number of persons exposed to radiologic hazards. With this increase it is essential that physicians and other scientists be acquainted with the dangers accompanying the handling of radioactive materials. Four cases of beta ray burns of the hands are reported here for the purpose of supplementing the present information in the existing literature,1 and emphasizing the early clinical course, as well as the laboratory observations in such cases. It is hoped that, by calling attention to the early signs and symptoms of injury by beta radiation, overexposure will be recognized and hazardous operations discontinued before more damage is incurred.All 4 men were injured while undertaking procedures of a like nature at the recent atomic tests at Eniwetok Atoll (United States Atomic Energy Commission's proving grounds). This work involved the handling of radioactive materials which emitted large amounts of beta and gamma radiation. A deviation in the prescribed procedure undertaken to expedite the operation resulted in the handling of these radioactive substances directly with rubber-gloved and sometimes with bare hands rather than with the remote handling devices that had been provided. Measurement of the dosage of beta rays received by the patients was not obtained at the time of exposure, but film badge and pocket ionization chambers worn by the men over the thoracic region showed readings for gamma rays varying from 1 to about 15 r. In view of the fact that the hands were much closer to the active material, it must be presumed that the amount of gamma radiation received by the hands was somewhat larger, probably by a factor of 10.The major portion of the radiation consisted of beta rays with an average maximum energy of about 1 Mev.(million electron-volts). The ratio of beta counts to gamma counts in a glass-walled Geiger-Mueller type tube was about 6 to 1. The physical properties of beta rays of 1 Mev. maximum energy are such that approximately 90 per cent of the incident rays are absorbed by the first 3 mm. of tissue and 99 per cent are absorbed in 6 mm. of tissue.2 Estimates of dosage indicated that these 4 men received from 3,000 to 16,000 rep (roentgen equivalent physical) to the outer surface of the skin.3 The beta ray dosages below the surface of the skin would then be 300 to 1,600 rep at 3 mm. and 30 to 160 rep at a depth of 6 mm. In view of the fact that there was definite evidence that the whole body exposure did not exceed 15 r of gamma rays in any case, it was believed that there was minimal, if any, danger of important whole body effect, and the patients were treated primarily for local beta ray burns of the hands. This assumption was borne out in the course of the disease, in that at no time was there any significant evidence of other than local damage.Since the amounts of radiation received and the clin¬ ical courses of the patients differ to some extent, each case is reported separately. Following is a brief synop¬ sis ...
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