508 BIOLOGICAL EFFECTS OF RADIATION 



prominent throughout the frontal region, which was not irradiated. 

 The main injury thus was related to the blood vessels, even those of 

 considerable size. 



Bagg (12, 90) showed a focal destruction and occasionally cyst forma- 

 tion produced in the brain by the implantation of radon in glass capil- 

 laries. Cairns and Fulton (33) placed radon seed screened with 3 mm. 

 platinum beside the spinal cord and within the dura on the dorsal 

 surface in the lower dorsal region. Doses varying from 9.8 to 31.3 mc. 

 caused complete paraplegia within a few days in cats. 



Pendergrass et al (265) report that after exposure of the brain and 

 cord of dogs to 1000 mg. hr. of radium, an extensive edema of the irra- 

 diated tissues is produced with severe symptoms, suggesting the produc- 

 tion of considerable damage and elaboration of connective tissue. This 

 is somewhat dependent upon the region irradiated. 



Peripheral Nervous System. — Swann (345) thought that the sympathet- 

 ic nervous system was more sensitive after short exposure and depressed 

 after long exposure, though his experiments are open to serious objec- 

 tions. Langer (190) reviews the effect of roentgen rays on the autonomic 

 nervous system; he concludes that the irradiation has a depressing effect. 

 Salinger and Thiel (315) irradiated in patients the superior cervical 

 ganglion and ciliospinal center of one side. They report changes of 

 pressure in the eyeball with protrusion of the bulb with later retraction 

 and pupillary dilation. They posulated that roentgen rays had a 

 definite influence on the vegetative nervous system. This has not been 

 checked in animals and in view of the pathology present in such patients, 

 the proof of this contention is still lacking in the reviewer's opinion (for 

 bibliography see 41, 128, 206, 236). Regaud (292), Warren (371, 372) 

 and others have noted the presence of apparently intact ganglion cells 

 and plexus cells in various organs severely damaged by irradiation, 

 especially stomach and intestine. 



Where changes in growth have been obtained, this is best explained 

 by the possibility of producing damage to the special glands connected 

 with the central nervous system, especially the pituitary. 



Del Buono (67) irradiated the pituitary region, in rabbits and thought 

 he detected slight changes in blood pressure with return to normal in 24 

 hr. There were also a leucocytosis and hyperglycemia, but in general 

 the amounts of change found are within the experimental error when 

 rabbits are used. 



The excitation of pain in the end organs in the skin when the latter 

 are damaged does not necessarily indicate that the end organs themselves 

 or the nerve trunks have been directly damaged by the radiation, but 

 they are secondary indicators of the damage produced in the local struc- 

 tures. There are acute changes in the skin following intensive irradia- 

 tion which are accompanied by pain only during the height of the skin 



