Page 24 of Attachment H 
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2. While fever was a problem with the earlier batches that 
contained large amounts of impurities, fever is rarely 
of concern with purified preparations of the enzyme. 
3. Nausea, vomiting, and anorexia also occurred more 
frequently when pyrogenic preparations were used. 
Endotoxin was probably a contributory factor in 
their pathogenesis. 
4. With regard to immunogen icity, these investigators state: 
"Perhaps the most surprising thing in this respect was 
that the administration of an _E. col i protein over a long 
period of time was not more troublesome." 
I 
Even with the crude preparations used in this study and the second course of 
treatments given to some patients, there were no fatal anaphylactic 
reactions. 
Concerning endotoxin contamination of _E. col i asparaginase, it is of 
interest that Loos and associates at the National Cancer Institute found 
that thirteen out of fifteen asparaginase lots that they examined gave an 
appreciable inhibition of whole human serum complement, an activity 
associated with endotoxin (2). The anti-complementary activity could be 
completely separated from the enzyme activity by gel filtration on Sephadex 
G-200 as shown in Figure 2. Fractions containing the asparaginase activity 
had no effect on whole human serum complement, or on the first component of 
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