SPECIFIC AND NONSPECIFIC RESISTANCE 

 SUMMARY 



In a series of experiments with mice, designed to explore the 

 effect of low ambient temperatures on host- parasite relations, the 

 following observations have been made: 



1. The core temperature of mice exposed to 2° C stabilized 

 within 24 hours 1° C to 2° C higher than that of mice maintained 

 at 21° C. 



2. The bacterial challenge agents, K. pneumoniae and S, aureus , 

 were shown to be capable of growth at the core temperature fluc- 

 tuations. 



3. The K, pneumoniae employed was passed through and isolated 

 from mice maintained at 2° C. This organism was equally capable 

 of growth at incubation temperatures of 32° C or 37° C, although 

 the oxygen requirements were one-half that required at 37° C. 



4. Specific immunization resulted in the best protection when 

 compared to zymosan or endotoxin treatment. 



5. Zymosan and endotoxin treatment often resulted in increased 

 mortality in mice exposed to 2° C and challenged with bacterial or 

 viral agents. 



6. Grouping of mice exposed to 2° C was significantly beneficial 

 to survival following challenge as compared to singly-caged mice. 



7. Acclimatization to 2° C resulted in equivocal protection to 

 mice challenged with bacterial agents but was beneficial to mice 

 challenged with a Coxsackie virus strain. 



8. Low ambient temperatures influence the course of Ehrlich 

 Ascites tumor disease process by retardation of mortality but do 

 not affect the over- all mortality ratio. 



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