IMMUNE OP SON INS AND BACTERIOTROPINS 97 



diseases in which active cellular destruction is known to occur, or 

 even some of the pathological lesions, may not be the outcome of the 

 formation of autocytotoxins. Observations in this direction are as 

 yet too meagre to warrant any far-reaching conclusions. I would 

 merely call to mind the now well-established fact that the serum in 

 various pathological conditions has been shown to be hemolytic for 

 the red cells of other individuals, and while there is evidence to show 

 that the cells of the same individual (i. e., the one furnishing the 

 serum) are more resistant, the thought naturally arises, whether the 

 anemia which is so frequent in the very diseases, in which autohemo- 

 lysins have been demonstrated, viz., syphilis, tuberculosis, and cancer, 

 may not in a measure be due to the action of such antibodies. 



It has been argued that if such antibody formation actually did 

 take place the harm done would be progressive, unless indeed an anti- 

 autocytotoxin formation in turn were to occur. The production 

 of such bodies also has actually been demonstrated by a number 

 of observers (Bordet, Miiller, Ehrlich, and Morgenroth), and it has 

 been shown, moreover, that these substances are of the nature of 

 antiamboceptors. Of their role in the animal organism, however, as 

 well as that of the auto-antibodies themselves, our knowledge is still 

 most imperfect and a discussion of the various possibilities would at 

 present amount to little more than a philosophical discourse. 



Immune Opsonins and Bacteriotropins. Further studies have shown 

 that in addition to the various types of antibodies with which we 

 have met so far there are still others to be considered. 



We have had occasion to point out in a previous chapter that in 

 the course of various infections, substances appear in the blood which 

 prepare the corresponding organisms for phagocytosis, but which 

 differ from the normal opsonins in their greater thermostability ; 

 these bodies have been designated as immune opsonins and bacterio- 

 tropins. Bodies of this character have been demonstrated following 

 immunization with the streptococcus, pneumococcus, staphylococcus, 

 meningococcus, the cholera vibrio, the typhoid and paratyphoid 

 bacillus, the dysentery bacillus, the tubercle bacillus, the plague 

 bacillus, and the anthrax bacillus. Of their mode of action nothing 

 definite is known. Neufeld inclines to the belief that they produce 

 some alteration in the physico-chemical status of the cell, in virtue 

 of which some constituent of the cell body is transformed into a 

 soluble modification which now surrounds the organism with a 

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