Morphological Changes in Animals Following Repeated Irradiation with Low-Intensity Short Waves
During prolonged (5 months) and repeated irradiation with short waves of low intensity (2250 V/m) the animals showed no effects of hyperthermia. Their condition was good at the time of sacrifice. Microscopic investigation revealed ill-defined degenerative changes in the nervous system. Increased argyrophilia and irregular thickenings and pools of axoplasm were found in the sensory nerve fibrils of the skin and viscera (Fig. 30e). No evidence of fragmentation of the nerve fibrils was observed. Damage to the nerve fibrils was not noticeably more severe in the skin or viscera. Shrinking and dark staining of individual groups of neurons (Fig. 32d) was found in the cortex, and the cytoplasm of hypothalamic neurons showed vacuolation, frequently with evidence of karyocytolysis (Fig. 33e). Slight degeneration of the myocardial muscle fibers was expressed as unevenness of staining. After more prolonged irradiation, mild degenerative changes occurred in the spermatogenic epithelium of individual tubules of the testes, sometimes with deposition of albuminous masses in their lumen. However, spermatogenesis was intact in most tubules. After a shorter period of irradiation (1.5 months) all these changes were less severe. Fatty degeneration of individual groups of hepatocytes and cloudy swelling of the epithelium of individual convoluted renal tubules were observed in the viscera and were accompanied by proliferation of reticuloendothelial cells in the liver, sometimes with the formation of histiocytic nodules (Fig. 38e), and by proliferation of perivascular round cells in the lungs.