SPECIFIC AND NONSPECIFIC RESISTANCE 



Temperature Treatment Mortality ratios at lu days 



(grouped) 



210 C 



Normal 

 Immune 

 Zymosan 

 Endotoxin 



10/10 

 0/10 

 3/10 

 8/10 



20 C 



Normal 

 Immune 

 Zymosan 

 Endotoxin 



10/10 

 0/10 

 1/10 



10/10 

 0/10 



Table XIII. Effect of chronic cold stress (2° C) on mortality of mice challenged intra- 

 peritoneaUy with 10 LDgQ* of Klebsiella pneumoniae . Animals maintained for 30 days, 

 immunized or treated and challenged at noted temperatures. *10 LDgg of K« pneumoniae = 

 1000 organisms per mouse. 



more definitive results concerning the efficacy of specific and non- 

 specific immunization under these conditions. Table XII shows the 

 results obtained for animals challenged with S. aureus , and it is evi- 

 dent that chronic cold stress did not interfere with specific immune 

 processes. Specifically immunized animals were significantly pro- 

 tected against parenterally induced disease even when exposed to 

 challenge doses as high as 10 LD50 's« There was no protection af- 

 forded the animals pretreated with zymosan or endotoxin. It should 

 be mentioned here that the strain of S. aureus employed caused the 

 deaths of the animals within 24 hours post- challenge. Those animals 

 surviving the first 24 hours usually did not die subsequently. There- 

 fore, the experiments were terminated at 14 days. 



Table XIII shows the results of chronically cold exposed animals 

 challenged with K. pneumoniae. Again, as noted in experiments al- 

 ready described, the specifically immunized animals were signifi- 

 cantly protected against thetenLD^Q challenge. Endotoxin treatment 

 yielded no protection to the mice. In contrast, the zymosan treated 



181 



