Acute radiation changes in the Purkinje cells; a study of C3H mice and a patient subjected to fractionated ionizing radiation.

Abstract

acute changes induced in the Purkinje cells of rabbits by single massive doses (1,000 to 4,000 r) of ionizing radiation have been reported by Campbell et al. (2). In a similar study on rabbits, Russel (14) observed subacute changes three months after the administration of 2,850 r. She was unable to reproduce these results in the brains of mice treated under equal conditions. The study to be reported here deals with the early changes in the Purkinje cells of C3H mice subjected to total doses of radiation varying from 267 to 5,340 r (air dose) delivered in sixteen to thirty-two days. It is hoped that these findings may throw some light on the histo-pathological phenomena which may possibly occur in the human brain treated with fractionated radiation. One such case will be described. Materials and Method A total of 40 C3H mice weaned at two months and weighing 19 to 22 gm. each was used. C3H mice were chosen because Reinhard (13) had reported that mice of this strain survived a single x-ray dose of 1,400 r to the head, while dba mice tolerated only 500 r. Thus a larger dose of radiation could be given before maximum tolerance was reached. One-half of the 40 mice were irradiated and the other half served as controls. The anesthetized animal was placed in a prone position on the surface of a firm cotton pad 3 cm. thick, covered by oilcloth and a paper towel. This pad rested on a wood table top of 2 cm. thickness. A lead plate 2 mm. thick and 15 × 15 cm. in area was placed over the animal, with only the head exposed through an 11 × 11-mm. aperture. A circular treatment cone of 4.2 sq. cm. was used. Treatments were given Monday through Friday, with a 100-kvp generator, with a half-value layer of 1.4 mm. aluminum, at 18 cm. skin-focus-distance. The dose rate was 246 r per minute measured in air. Each mouse (both experimental and control) was anesthetized with 1.2 mg. of Sodium Nembutal injected intraperitone-ally before irradiation. On the first day, all 20 experimental mice were irradiated. On each succeeding treatment day one less mouse was treated, so that on the twentieth day, only 1 was irradiated. Each animal, together with its control, was sacrificed on the day following its last treatment. Thus, the first mouse received 267 r and the twentieth mouse received 5,340 r. During their lifetime, the mice were kept in groups of 5 per cage and were given the same food and care as the control animals. Immediately after the animal was sacrificed, the head was separated from the body and the brain was removed and divided in half through an incision along the longitudinal fissure. One-half was prepared for staining by hematoxylin and eosin, the other half for Elftman's (4) modification of the Golgi stain.