TUNEVALL AND LINDNER 



It was interesting to note that hardly any pneumonic lesions were 

 found in the hypothermic group, but in five normothermic mice all 

 with a survival time of 30 hours or more. 



In the previous experiment the inoculation resulted inbacteremia 

 which was always established after two hours in the normothermic 

 group. In the hypothermic group, however, two animals had sterile 

 blood after two hours and one of them after eight hours. In order to 

 investigate if bacteremia could be regularly postponed by hypother- 

 mia, a less massive infection was induced in the following experi- 

 ments, as the propagation of such an infection into the blood stream 

 seemed more likely to be influenced by the hypothermic state. 



In one of these experiments, presented in Figure 11, the hypother- 

 mic as well as the normothermic group contained eight mice. Two 

 hundred thousand pneumococci Type II were inoculated (i.p.) 5 hours 

 after the start of hypothermia. Hypothermic animals were warmed 

 up 48 hours after the inoculation. Also, the increase of the bacterial 

 counts was slower in the hypothermic group, and after as long a 

 time as 40 hours, bacteremia had developed in only 3 of the 8 hypo- 

 thermic mice, but in all normothermic animals. However, the re- 

 warming was noxious to the hypothermic mice. Three bacteremic 

 animals already in the hypothermic state died during this procedure; 

 two other mice died as well, but without developing any bacteremia; 

 and the remaining three died within 15 hours from the start of the 

 rewarming procedure and proved to be bacteremic when autopsied. 

 Consequently, no significant difference between the two groups as 

 to the mean survival time was found. 



A similar experiment is presented in Figure 12. Here, 5,000 

 Type II pneumococci were given (i.p.) to seven mice five hours 

 after the start of hjrpothermia which was maintained for 40 hours. 

 Two normothermic control groups were run, one of which was 

 given premedication. The results were similar within both con- 

 trol groups, and they will be treated together. 



The results tallied well with those of the previous experiment. 

 Bacterial multiplication was slower in hypothermic mice, and three 

 such mice were protected from bacteremia, whereas all controls 

 became bacteremic. Rewarming was fatal. All surviving mice 



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