On the occasion of the author's visit to Wright's clinic (1911) he stated that he used the determination of the opsonic index chiefly as a guide to the dosage in the use of vaccines.
The phagocytic index of a given serum divided by the phagocytic index of a normal serum gives the opsonic index of the serum tested.
Assuming the normal opsonic index to be 1, Wright asserts that in healthy individuals the range should be not more than from 0.
The opsonic power of a serum normal or otherwise is determined by mixing an emulsion of fresh leukocytes in normal saline solution with a suspension of the bacteria and with the serum to be tested.
Most workers outside the Wright school have failed to recognize any essential value of determinations of the opsonic index in the use of vaccines.
In the method for demonstrating opsonin about to be described, a comparison is made between the opsonic "power" of the pooled serum and the specific serum.
This fraction, expressed as a percentage of unity = the opsonic index.
The phagocytic index of the blood under investigation, divided by that of the normal blood, gives the opsonic index of the former, the opsonic index of the normal blood being taken as 1.
Wright and his followers regard the opsonic index as an index of the power of the body to combat bacterial invasion.
Wright has devised a delicate method of examination of the blood (the calculation of the opsonic index) which tells when the tuberculin injections should be resorted to and when withheld (see BLOOD).
In other forms of infection, vaccines are employed to increase the opsonic power of the blood.
The object in such treatment is to raise the opsonic index of the serum, this being taken as an indication of increased immunity.
If then an additional quantity of vaccine be injected there occurs a fall in the opsonic index (negative phase) which, however, is followed later by a rise to a higher level than before.
In regulating the administration of such vaccines he has introduced the method of observing the opsonic index, to which reference is made below.
By opsonic action is meant the effect which a serum has on bacteria in making them more susceptible to phagocytosis by the white corpuscles of the blood (q.
If the amounts of vaccine used and the times of the injection are suitably chosen, there may thus be produced by a series of steps a rise of the opsonic index to a high level.
The effect of the injection of a small quantity of vaccine is usually to produce an increase in the opsonic index within a few days.
Variations in chemiotaxis towards different organisms probably depend in natural conditions, as well as in active immunity, upon the opsonic content of the serum.
In estimating the opsonic power of the serum in cases of disease a control with normal serum is made at the same time and under precisely the same conditions.
More recently, the discovery of the "opsonic index," and its use by Sir Almroth Wright and others, has given a great advance to the observation and treatment of cases of tuberculosis.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "opsonic" in a variety of sentences. We hope that you will now be able to make sentences using this word.
