872 XIV. NUTRITIONAL VALINE OF FATS 



and Brucella melitensis. Dimyristate had the greatest bactericidal effect 

 against Diplococcus pneumoniae and Streptococcus pyogenes. 



According to Friedewald/'*^ the immunizing effect of a PRS strain of 

 influenza vaccine was enhanced by the addition of killed acid-fast AIijcu- 

 bacterium butyricum (from milk and butter) suspended in sesame oil. 

 The influenza virus induced four times as much antibody formation when 

 the M. hutyricum was given in sesame oil as when it was suspended in 

 saline alone or in sesame oil in combination with killed typhoid bacilli. 



In 1908 Landsteiner and Ehrlich^'*^ noted the strong bactericidal action 

 of aqueous organic extracts of animal fats on Bacillus anthracis and on 

 other bacteria. They found that serum and bone-marrow fat acted as 

 bacteriolysin, and suggested that the bactericidal combination of protein + 

 lipid acts in a similar manner as amboceptor and complement. The com- 

 plements in the blood serum are probably lipoids. The importance of 

 this possibility in immunity is suggested. In this connection, Eagle, ^'*^ 

 in his studies of the serology of syphilis, discusses the complement-fixing 

 properties of the lipoid-reagin precipitate. A film of normal serum pro- 

 tein does not interfere with the specific reaction between antigen particles 

 and subsequently added syphilitic serum (reagin). The protein is only 

 loosely bound, and does not obscure the specific reacting groups of the 

 lipoid. However, the lipoid-reagin precipitate incubated with very strongly 

 positive syphilitic serum does not give any further reaction; the first 

 incubation has covered the reacting groups of the lipoid with closely ad- 

 herent reagin-globulin, so firmly bound as not to allow combination with 

 more reagin, until the protein film has been destroyed by heating. 



M. Lwoff^^^ found that certain bacteria, for example Hemophilus per- 

 tussis (found in whooping cough), produce fatt}' acids which inhibit their 

 own gro^^'th and that of other bacteria. Cholesterol may neutralize these 

 acids, as it is essential to the growth of the organism. Very low concen- 

 trations of oleic acid (0.01 to 0.03 mg./ml.) stimulate Entameba terrapinae 

 of reptiles, but the acid has a toxic effect at high concentrations. A mix- 

 ture of oleic acid and cholesterol does not permit multiplication of the or- 

 ganism. Von Brand^^^ found that, although the halogenated acetic acids 



"2 W. F. Friedewald, /. Exptl. Med., 80, 477-490 (1944). 



"3 K. Landsteiner and H. Ehrlich, Centr. ParasUenk., 4-5, Abt. I, 247-257 (1908). 



1" H. Eagle, /. Exptl. Med., 52, 717-738 (1930). 



1^ M. Lwoff, Nutrition of Parasitic Amebae, in A. Lvvoff, Biochemistry and Phijsiology 

 of Protozoa, Vol. /, Academic Press, New York, 1951, pp. 235-250. 



"* T. von Brand, Metaholisin of Trypanosoniidae and Bodonidae, in A. Lwoff, Bio- 

 chemistry and Physiology of Protozoa, Vol. /, Academic Press, New York, 1951, pp. 177- 

 234. 



