498 BIOLOGICAL EFFECTS OF RADIATION 



Mottram and Kingsbury (245) suggest that following the injury of 

 the intestine by radium radiation there is an interference in the produc- 

 tion of mucus by the mucosa which precedes the necrosis of the epithelial 

 cells. They found that an invasion of the tissue of the mucosa by 

 bacteria follows the production of the desquamation already referred to. 

 They believe that the thrombopenia which they could produce was a 

 secondary effect, along with the presence of the bacteria in the blood, to 

 the breaking down of the epithelial barrier of the intestine against bac- 

 terial invasion. Their experiments probably involve severe bone-mar- 

 row injury as well as intestinal injury and they were studying the 

 combined effects of these two injuries. 



Further studies on the chronic degenerative lesions might give infor- 

 mation concerning the mechanism of absorption and secretion, provided 

 the proper biochemical method could be set up. The same is true of 

 similar lesions produced in the stomach and colon. The effect of radi- 

 ation from radium administered from outside the body is essentially the 

 same as that of roentgen radiation. 



From clinical observations in the literature it is probable that the 

 human small intestine is likewise sensitive to damage (16) and by the 

 same dose {i.e., some injury may be produced by less than the human 

 erythema dose). Sanders (317) reports stenosis of the small intestine 

 in patients receiving radiation over the abdomen one-half year pre- 

 viously. The fatal intoxication following irradiation over the abdomen 

 is dependent upon a rather critical dosage, for with a less severe reaction 

 {i.e., from less dosage) the result is that of acute partial injury and 

 destruction of some of the same crypt cells followed by various stages of 

 degeneration and repair. The repair is characterized by the prolifera- 

 tion of connective tissue and blood-vessel capillaries into the fibrin-rich 

 covering clinging to the denuded surface and the regeneration and rapid 

 growth of the cell remnants, apparently from the crypt-cell group. The 

 repaired surface is apt to contain abnormal and degenerate cells. There 

 is frequently a fair number of mucus-secreting cells in addition. The 

 reviewer is inclined to believe that the repaired portion, since it is covered 

 by abnormal cells, does not permit normal digestion and absorption to 

 occur. In extreme cases this may be almost nonexistent. This would 

 account for the survival of the experimental animals past the acute 

 stages, and explain the continued loss of weight and occasionally exitus 

 from starvation, after a considerable period of time if the lesion is exten- 

 sive enough. The placing of radium within the bowel, especially within 

 isolated loops, or the irradiation from without of isolated loops, might be 

 a suitable method of determining how these destructive agents bring 

 about such specific and localized disturbances of function. 



On the injection of radioactive substances such as thorium X, or 

 radium chloride, the small intestine is damaged by the radiation given 



