VIRULENCE AND BACTERIAL INFECTION 



and put them into the cage, the tenth mouse will have a temperature 

 one degree higher than the first one just because of your reaching 

 in and stirring these animals up. 



PREVITE: Regarding that, I noticed that when a timer with 

 a bell was used in order to leave the rectal thermistor probe in 

 the cold exposed mouse for exactly 15 seconds, the stress of 

 the ringing bell at the end of this period seemed to affect the 

 rectal temperature measurement. Rectal temperatures were 

 lower in mice for which a wristwatch was used to time the 15 

 second period of thermistor probe insertion. Apparently the 

 sound of the bell served as a stress which could affect body 

 temperature measurements. 



BLAIR: Adolph at Rochester and Crisman at Stanford, in order 

 to produce h)^othermia in mice and rats, used no anesthesia. 

 It was necessary to restrain the animals. If they were not re- 

 strained, no matter how loi^ they were exposed in an environ- 

 ment of 0^ C to 5 C, they do not achieve a hypothermia. 



WALKER: What is meant by hypothermia? How low is it? 



BLAIR: He has taken it down as low as 18" C or 15 C, but the 

 strain on the mice and the initial activity causes elevation in 

 the body temperature, but within several hours they are cooled 

 down quite extensively, as opposed to the group which is allowed 

 to run around in the cages. So the strain is important. This is 

 related to the muscle activity you are talking about. 



REINHARD: What was your statement relative to the genetics 

 of the organism and the host- parasite relationship? 



PREVITE: We noted that there is a difference between viru- 

 lent and avirulent strains. The genetic constitution of the para- 

 site can be very important in determining the outcome of the 

 infection as modified by cold exposure. 



REINHARD: In a homozygous physiologically standardized host? 



PREVITE: I made no reference to the host at all, but I would 



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