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PHAGOCYTOSIS. OPSONINS AND BACTERIOTROPINS 



of the immune as well as of the normal opsonins has not been clearly 

 defined. It is still a matter for investigation whether in the case of 

 opsonins one is dealing with entirely new substances or whether they 

 are the old well-known bodies like the agglutinins, complements and 

 amboceptors with a new action. 



The fact that the opsonic index is raised by immunization while it is 



usually found diminished during spontaneous infection in man, led 



Wright to believe that good results may be obtained by 



Increase of increasing the opsonic index of the already infected individual 



Opsonic by means of immunization. In this way he thought the 



Index by Im- patient's predisposition to the particular infection would 



munization. be overcome . Wright's experiments showed that the opsonic 



index could be increased by injection of extremely small 



doses of dead bacteria (Wright's vaccines.) 



If an individual suffering from an acne or furunculosis, and who has a low opsonic 

 index for the staphylococcus, is injected with a very small number of staphylococci, his 

 opsonic index sinks still more for a short period after the inoculation (negative phase). 



This is explained by the fact 

 that the injected bacteria absorb 

 the existing opsonins. New 

 opsonins are, however, then 

 produced, which immediately 

 make up for the loss occasioned 

 during the negative phase, with 

 the result that after several days 

 there is an increase of the opsonic 

 index (positive phase) which 

 lasts for a short time. Then 

 the index again begins to fall, as 



the stimulus to the formation 

 CHART 5. Curve of the opsonic index following the . . 



inoculation of a small dose of staphylococcus vaccine. of P sonms 1S transitory. It 

 The arrow indicates the time of injection. usuall y sinks to below the nor ~ 



mal level, only to rise again to a 



point slightly above the normal, where it remains stationary. This irregular curve 

 represents the typical course of the opsonic content of the blood after a vaccine injec- 

 tion; apart from this characteristic picture numerous exceptions exist. Thus by the 

 use of very minute bacterial doses, the negative phase immediately following the 

 injection is entirely absent. Reversely very large doses exhibit a prolonged nega- 

 tive phase. 



Wright graphically represents these variations in the opsonic index by 

 charts, an example of which is given here (Chart 5). 



In order that the therapeutic effect may persist, it is advisable to 

 repeat the inoculation. A new injection should be given at the height 

 of, or during the positive phase, as an inoculation repeated during a 

 negative phase will result in further depression of the index to a very 

 low level. It is even possible in this way to harm the patient. The 



Opsonic 

 Index 



Normal 



