878 THOMAS ORDWAY AND ARTHUR KNUDSON 



From the above it appears that the x-rays have two actions aside from 

 the direct effect upon the tumor. First a large dose destroying the im- 

 mune condition will favor the growth of tumor, a small dose producing 

 the immune condition helps to inhibit the growth of tumor. 



Such studies indicate that in treating growths by radium or x-ray a 

 treatment directed solely toward the primary growth may favor metastasis 

 by lowering the natural powers of resistance of the patient, especially if. 

 comparatively large doses are repeated at too frequent intervals. Murphy 

 believes that great caution should be used about destroying the lymphocytes 

 which seem to play the defensive role in malignant growths. 



Up to the present time the x-ray has only increased the resistance to 

 inoculated cancer. Yet there is a distinct analogy between such and 

 metastatic deposits of a spontaneous growth. Hence it is suggested by 

 Murphy -that repeated small doses of x-rays at intervals might similarly 

 increase resistance against the development of secondary, metastatic 

 growths. 



Rohdenburg and Bullock by heat and exposure to radium have in- 

 creased the susceptibility in mice and rats to the immunizing action of 

 homologous living cells and the additional immunity thus obtained may 

 be one hundred per cent over the usual figure. The growth energy of 

 transplanted tumors also can be depressed by radium (Wedd and Russ). 

 This retardation of growth energy persists only a few generations of 

 transplants (Wood and Prime). 



Believing that there might be a relation between the number of lym- 

 phocytes in the disease poliomyelitis and the susceptibility of monkeys to 

 experimental poliomyelitis Amoss, Taylor and Witherbee reduced the 

 circulating lymphocytes in such animals by properly controlled doses of 

 x-rays such as were used by Taylor, Witherbee and Murphy. Six Holz- 

 knecht units of unfiltered x-rays was given at each dose on the dorsal and 

 ventral surface of the animal. Spark gap was three inches, milliamperage 

 ten, distance twelve inches (Coolidge tube), time four minutes. The 

 animals were treated every day or every other day until the total lym- 

 phocytes per c.mm. were about 1000 to 2000. Animals thus exposed to 

 x-rays were susceptible to three-fourths of a dose which was not infective 

 for non-rayed controls. This suggests a relation between the lymphocytes 

 and one factor of resistance in poliomyelitis. They were not able to reduce 

 the immunity by exposure to x-rays in a monkey immune from a previous 

 attack of poliomyelitis. 



Effect on Enzymes. Richards (6) believes that the biological reactions 

 resulting from exposure to radiations are due in large part to the effect 

 upon the body ferments. Richter and Gerhartz in studying the action 

 of x-rays upon rennin, yeast, pepsin, pancreatin and papain concluded 

 there was no effect on these ferments. Richards (a), however, believes that 



the experiments of these authors do show slight changes which may be at- 



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