-T^ov. 19, 1921 Hemotoxins from Parasitic Worms 427 



is still open to speculation, but the view that toxic substances from 

 parasitic worms are of etiological significance in parasitic diseases i^ 

 supported by convincing evidence. 



XIV. SUMMARY 



Extracts of A scar is lumbricoides contain active substances that affect 

 blood deleteriously. The hemolysin which these extracts contain is a 

 thermostabile, nonspecific, alcohol-soluble substance which appears to be 

 rather firmly bound to the cells of the parasite, presumably to the cells 

 of the intestine in which it is elaborated. The hemolytic potency of 

 extracts of A. lumbricoides is not due solely to fatty acids, since chemical 

 fractions of the worms from which the fatty acids have been removed 

 by ether extraction are hemolytic. The hemolysin is neutralized by 

 normal blood serum. 



The body fluid of A. lumbricoides shortly after removal from the host 

 contains oxyhemoglobin and is nonhemolytic. It acquires hemolytic 

 powers, however, as the worms are kept alive in vitro for a few days, 

 and loses at the same time its oxyhemoglobin content. 



Body fluid from fresh specimens of Ascaris lumbricoides does not acti- 

 vate a hemolytic system, and alcohol-soluble fractions of the worms 

 from which ether-soluble substances have been removed does not act 

 as complement in combination with inactivated normal guinea-pig serum. 



The hemagglutinin from Ascaris lumbricoides is a salt-solution-soluble 

 substance and has special affinities for rabbit blood cells. Unlike the 

 hemolysin, its action is not hindered by low temperatures (6° to 8° C). 



Ascaris lumbricoides secretes a substance that inhibits the coagulation 

 of blood. This substance is present in the body fluid of the worm and 

 iias but a comparatively slight potency. 



Ancylostom,a caninum secretes a nonspecific hemolysin, soluble in salt 

 solution, relatively thermolabile and inactive at low temperatures. 

 Normal blood serum inhibits the action of the hookworm hemolysin. 



Bustomum phlebotomum secretes a hemolysin having properties similar 

 to that of Ancylostoma caninum. This hemolysin is completely soluble 

 in alcohol. 



Salt-solution extracts of Haemonchus contortus have but a feeble 

 hemolytic action. 



Salt-solution extracts of Ancylostoma caninum and of Bustomum 

 phlebotomum do not inhibit the coagulation of rabbit blood to any marked 

 degree. 



A weak hemolytic substance is present in extracts of Trichuris depressi- 

 uscula. 



Thysanosoma actinioides contains an alcohol-soluble hemolysin. Alco- 

 hol-soluble fractions of T. actinioides from which the ether-soluble fraction 

 has been removed are hemolytic, showing that substances other than fatty 

 acids are involved. The hemolysin from this cestode is active at 8° C. 

 70495°— 21 4 



