PHAGOCYTOSIS OPSONINS AND BACTERIOTROPINS. 



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, lead Wright 



to believe that good results may be obtained by increasing the 



Increase of opsonic index of the already infected individual by means of 



Opsonic Index immunization. In this way he thought the patient's pre- 



by Immuni- disposition to the particular infection would be overcome, with 



the consequent obtention of the essential requirements for a 



cure. 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 for the formation of 

 opsonins is transitory. It usually 

 sinks to below the normal level, 



CHART 5. Curve of the opsonic index following the 

 inoculation of a small dose of staphylococcus vaccine. 

 The arrow indicates the time of injection. 



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 injection; 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 negative 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 unto a very low level. It is even 

 possible in this way to harm the patient. The poor results obtained during 

 the first era of tuberculin treatment can, according to Wright, be attributed 

 to the failure of this observation. It is the production of cumulative positive 

 phases that is the aim of vaccine treatment. (Chart 6). 



