512 BIOLOGICAL EFFECTS OF RADIATION 



There have been many recent studies of the circulating white hlood 

 cells of patients and workers (81, 125, 143, 178, 180, 234, 243) showing 

 that a leucopenia develops no matter what the method of irradiation or 

 wave-length used, the same proportionate fall occurring after the pro- 

 tracted, fractional irradiation that occurs after the massive-dose irradia- 

 tion or the use of Grenz rays (112, 113). Zwerg (404) irradiated a fold 

 of skin on the back of rats and found that a leucopenia was produced 

 from which the animal recovered within a week, suggesting that the 

 effect was upon the circulating cells only. Irradiation (600 r) of one of 

 a parabiotic pair was followed by a similar drop and rise with a later fall 

 in the white-blood-cell count of both animals. The changes are due to 

 a relative fall in the lymphocytes and an apparent rise of polymorpho- 

 nuclear cells in both animals. Injection of thorium X into mice, guinea 

 pigs, and chickens showed similar inhibition (destruction) of lympho- 

 cytes and macrophages (364). In culture, this amount did not affect 

 the fibroblasts but did damage the lymphocytes thus indicating even in 

 vitro the greater sensitivity of the adult lymphocytes. 



In vitro exposure of human neutrophile leucocytes (granulocytes) 

 indicates that the chief immediate biological effect of irradiation with 

 either roentgen or gamma rays or visible-light rays is the immobilization 

 of the granulocytes, and structural changes followed by death do not 

 occur until later (186, 365). 



A few workers report a leucocytosis immediately after irradiation 

 and apparently this is common in rabbits, but within 24 hr. there is a 

 definite leucopenia in all animals and in the human being. The leuco- 

 cytosis resulting from the injection of colloidal silver or turpentine 

 abscesses afforded no protection against a terminal leucopenia following 

 irradiation of the bones of dogs nor is the leucopenia affected by transfu- 

 sion (334). Platelet disturbances have been reported by Lacassagne 

 (186, 188, see also 334) in rabbits. Wright and Bullman (396) have 

 reported a decrease in platelets in the cat after prolonged treatment. 

 The number of circulating white blood cells in animals vary greatly 

 from time to time. It is the reviewer's opinion that many laboratory 

 animals are very unsatisfactory for such study, since considerable vari- 

 ation in the blood cells is apt to occur under laboratory conditions. 



Many workers have failed to produce hemolysis of the red blood cells 

 in vivo (180, 334) or in vitro (81, 180, 334) or to change the response to 

 hypertonic and hypotonic solution (fragility) after doses as high as 

 16 erythema doses (180, 334, 338, 348). Holthusen (158) was able to 

 produce hemolysis in vivo and the production of methemoglobin in the 

 circulating blood with 50 human erythema doses. 



Goulston (129) reported in the human, rat, and fowl bloods an 

 increase in the fragility of the red blood corpuscles after irradiation with 

 8400 mg. hr. of lightly filtered radium. There is an apparent difference 



