494 BIOLOGICAL EFFECTS OF RADIATION 



up much more than the whole blood or plasma. Certain frequencies 

 seem to show specific heating effects. This is very difficult to prove 

 in vivo because of the difficulty up to the present of measuring the actual 

 temperature gradients in organs under the influence of these "high- 

 frequency" electromagnetic fields. The changes described by Oettingen 

 (254) and Schliephake (325) are of two types, the acute damage which is 

 lethal, and chronic changes. Acute lethal damage is due for the most 

 part to complete or partial coagulation of vital tissue and in part to 

 the dehydration which may result from the elevation of the temperature 

 of the whole animal. The elevation of the white blood count with 

 increase in the polymorphonuclear cells and a relative decrease in lympho- 

 cytes which occurs after the exposure to this short-wave radiation is a 

 characteristic of the elevation of the body temperature rather than a 

 specific effect due to these electromagnetic radiations (3 to 300 meters) 

 for the same circumstance arises in patients and animals whose tempera- 

 ture is elevated artificially by other methods (radiant energy, chemical 

 poisons, etc.). In the acute lethal experiments (254) there is a gener- 

 alized hyperemia of all the organs, with edema and damage to blood 

 vessels and organ cells which in the reviewer's experience occurs at or 

 above a body temperature of 43°C. In the animals irradiated frequently 

 there are some degenerative changes in all the organs with various stages 

 of repair and disintegration. This, to the reviewer, means that the 

 organs are damaged by local elevations of temperature within the organs. 

 The temperature of the tissues was raised too rapidly for the blood 

 streams and local conduction to remove the excessive energy which 

 piled up to the point of damage or even to the point of coagulation. 

 There is considerable theoretical evidence to show that it may be possible 

 to bring about such localized heating in certain tissues without heating 

 the other tissues if the proper wave-lengths are used. 



GASTRO -INTESTINAL TRACT 



Changes in the gastro-intestinal tract produced by roentgen radiation 

 have been reviewed in some detail by Warren (369) and more recently the 

 experimental literature has been outlined in great detail by Desjardins 

 (74). 



Upper Portions. — The mucous membrane of the mouth, pharynx, and 

 esophagus does not differ materially in the type of reaction from that 

 noted in the skin except that the lesions are somewhat influenced by the 

 moist surface (and therefore the reaction depends upon the salivary 

 secretion to some extent), by the presence of digestive juices and food 

 (abrasion), and by the absence of the horny layer which acts as a slight 

 protective coat in the case of the skin. The radiosensitiveness of the 

 mucous membrane of the nose and its accessory sinuses has not been 

 determined experimentally. Excessive irradiation of the larynx (roent- 



