The Relation of Leucocytic Extract to Body Fluids. 29 



anesthetic and danger lines is narrow, and there is no reliable 

 danger sign. 



20 (716) 



The relation of leucocytic extract to body fluids. 

 By Wilfred H. Manwaring. 



[From the Laboratories of the Rockefeller Institute for Medical 



Research.] 



In a previous communication 1 it was shown that a com- 

 paratively strong bactericidal substance can be extracted from 

 horse leucocytes. This substance loses its bactericidal power, in 

 whole or in part, if it is mixed with homologous or foreign sera, 

 with pathological exudates, with cerebro-spinal fluid, with the 

 products of aseptic tissue autolysis, or with most of the products 

 obtained by the bacterial decomposition of tissues. It also loses 

 its bactericidal power if it is mixed with the products obtained by 

 the prolonged autolysis of leucocytes themselves. 



With sera that are in themselves bactericidal, not only is there 

 a loss of the bactericidal power of the leucocytic extract in such 

 mixtures, but there is also a destruction or inhibition of the bac- 

 tericidal power of the serum itself. This gives the phenomenon 

 of two bactericidal substances, an active serum and an active leu- 

 cocytic extract, added to each other, producing a non-bactericidal 

 substance, a good culture medium for bacteria. 



An analysis of the antibactericidal action of serum shows that 

 it is due to the combined effects of three factors: (1) the anti- 

 bactericidal power of the serum colloids, (2) the antibactericidal 

 power of sodium chloride and the other neutral diffusible serum 

 components, and (3) the antibactericidal action of the diffusible 

 serum alkalies. 



Alkalies are very strongly antagonistic to the leucocytic 

 bacteriolysin. The addition of 1/200 per cent. NaOH to leucocytic 

 extract is usually sufficient to completely inhibit its bactericidal 

 action. Acids, on the other hand, apparently have little or no 

 antibactericidal effect. 



This antibactericidal power of serum and tissue fluids can not 

 be overcome by increasing the amount of leucocytic extract in the 



1 These Proceedings, Vol. IX, 1912, p. 74. 



