COLD AND VIRUS INFECTIVITY 



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DISCUSSION 



REINHARD: Dr. Walker, what is the temperature of a baby 

 mouse? 



WALKER: I don't know, but I would like to. This brings up a 

 very interesting point. I indicated that we have begun work in- 

 volving using both tissues of baby mice and adult mice. It is 

 quite evident that raising the body temperature of a baby mouse 

 does not produce the same effects that I showed here for the 

 adult mouse. We have exposed infant mice to incubator tem- 

 peratures up to about 35° C. Above this temperature, the infant 

 mice do not survive. I think perhaps the baby mice could tolerate 

 higher temperatures, but the mother refuses to feed them or 

 her lactation stops at higher temperatures. She apparently has 

 enough troubles at that temperature without having these little 

 furnaces hanging on her, so she retreats to the opposite side 

 of the cage and the mice are not fed. I don't know what the tem- 

 perature of baby mice is at ambient temperatures of 35° C, 

 but I think it is probably higher than normal. I haven't succeeded, 

 so far, in finding a probe that will allow me to measure the 

 body temperature of a forty- eight- hour- old infant mouse. 



One other thing should be pointed out, too, and that is that the 

 pancreas appears to be different from other tissues. Coxsackie 

 virus will multiply in the pancreas of the adult mouse even at 



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