150 



-19 4 5- 



432. WELCH, H., PRICE, C. W., CHANDLER, V. L. and HUNTER, A. C. 



The: thermostability of pyrogens and their removal from peni- 

 cillin 



J. Am. Pharra. A. 3^:11^-118, 19^5 



Adsorptive filtration with asbestos filter pads will remove 

 the thermogenic substance from growing penicillia , but temp- 

 eratures of 250° C. for 30 minutes are required to destroy 

 bacterial pyrogens. Ampoules may not be pyrogen-free; all 

 other glassware used in tests should be subjected to 250® C. 

 heating for 40 minutes. 



^33. ZAHL, P. A., STARR, M. P. and HUTNER, S. H. 



Effect of bacterial toxins on tumors. VII. The tumor hemorrhage 

 factor in bacteria 



Am. J. Hygiene 41:41-56, 1945 



Tumor hemorrhage production was the criterion used for 38 

 strains of 25 species of plant pathogens. Suspensions of cul- 

 tures employed included those prepared from Agrobacteria , cory- 

 nebacterla, Pseudomonas and xanthomona strains . Of the 32 

 Ij'ypes" of streptococci in this study which were gram-positive, 

 it was found that' "a factor bound in the antigen of gram- 

 negative organisms is lacking. This factor has particularly 

 toxic affinity for vascular structures. Some connection exists 

 between hemorrhage production and lethality and the 'smooth' 

 type of Salmonella choleraesuis ; potency of this type is 10 

 times that of 'rough' strains. 



434. ZITTLE, C. A., DEVLIN, H. B., RODNEY, G. and WELCKE, M. 



Removal of bacterial pyrogens from protein hydrolysates 



J. Lab. Clin. Med. 30:75-79, 1945 



Heating to a temperature of 250 deg. P. for 30 to 40 minutes 

 will destroy pyrogens; or, in penicillin solutions, they may 

 be removed by adsorptive filtration with asbestos pads. 



