TUNEVALL AND LINDNER 



hours later, hypothermia was induced in six mice and maintained 

 for 2 hours in three animals and for 8 hours in the other three. 

 Five mice were kept nor mother mic. In this group all eleven mice 

 survived, but it is not included in the table. 



In the second group six mice were made hypothermic 1-1/2 to 2 

 hours after the toxin injection, and the other six kept normothermic. 

 All animals got antitoxin 4 hours after the toxin, and then the re- 

 warming of the hypothermic animals was immediately begun. In this 

 group no animal was saved, as seen from Figure 3, but the survival 

 was prolonged in comparison with the first experiment; especially 

 so in hypothermic animals. The difference effected by the hypo- 

 thermia was much larger than corresponded to the length of the 

 hypothermic period itself (80 versus 43 hours at two hours of 

 hj^othermia). 



The third group received antitoxin 10 hours after the toxin, 

 and the rewarming of hypothermic mice was also begun after 

 10 hours. In other respects this group was treated as the second. 

 The survival was still prolonged, but the difference between 

 hjTDOthermic mice and controls was only equal to the length of 

 hypothermia (50 versus 39 hours at 8 hours of h3T)othermia). 

 This experiment is also presented in Fig. 4, which states the 

 significance of the observations. 



As will be discussed later on, the effect of tetanus toxin may 

 be influenced by irrelevant factors. The next part of the study 

 was therefore performed with staphylococcal toxin which was, 

 as well as antitoxin, always administered intravenously in order 

 to avoid differences in absorption from local sites of injection. 

 Preliminary experiments had shown that a dose of staphylococcal 

 toxin large enough to kill all mice in the groups resulted in very 

 short survival, generally ranging between 1 and 4 hours. It was 

 further found that about 0.8 MLD,„„ was enough to kill mice 

 which had received the pretreatment whether they were made 

 hypothermic or not. 



In the first series of experiments, the influence of hypothermia 

 on the survival times after lethal doses of the toxin was in- 

 vestigated. Groups of normothermic mice which received the 



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