MIYA, MARCUS AND PHELPS 



kill challenged and acutely exposed animals. (2) Specific immunization increases re- 

 sistance of mice kept at 2° C.and this immunity is of the same magnitude as in animals 

 kept and immunized at room temperature. (3) Nonspecific immunization does not in- 

 crease resistance of cold acclimatized mice. 



Numerous reports on the influence of environmental temperature 

 on host-parasite relationship have appeared in the following litera- 

 ture: Pasteur, Joubert, and Chamberland, 1878; Lillie et al., 1937; 

 Fay and Henny, 1938; Armstrong, 1938 and 1942; Smith and Fay, 

 1939; Bischoff and Long, 1939; Sarracino and Soule, 1942; Fuller, 

 Brown, and Mills, 1941 ;Goldfeder, 1941; Wallace, Wallace, and Mills, 

 1942 and 1944; Mills and Schmidt, 1942; Muschenheim et al., 1943; 

 Sulkin, 1945; Ipsen, 19 52; Walker and Boring, 1958; Sulkin et al., 

 1960; Miya et al., 1962 ; Miraglia and Berry, 1962; Previte and Berry, 

 1962. There is general agreement that the physical environment 

 can alter or influence the course of disease; however, isolating the 

 specific factors involved remains difficult. Consequently, the re- 

 ports of results obtained by workers in this field are frequently 

 conflicting even thoughthe same challenge agents and animal species 

 may have been employed. 



During the past twoyears experiments have been conducted in our 

 laboratory to test the hypothesis that preceding or following exposure 

 to low temperatures, the capacity of experimental animals to resist 

 local or systemic infectious diseases is (a) unchanged or (b) in- 

 creased or decreased. Presumably, changes observed would be 

 mediated by humoral, cellular, or vaguely defined physiological 

 factors which may be isolated or otherwise identified for study. 



Our experiments have proceeded along three lines: (1) investi- 

 gation of the effect of low ambient temperature on host- parasite re- 

 lations in both unacclimatized and acclimatized animals following 

 experimental infection; (2) investigation of alteration of specific and 

 nonspecific resistance of animals exposed to cold stress; (3) in- 

 vestigation of the influence of low ambient temperature on the 

 progress of viral neoplastic disease in mice. 



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