Opsonins and their utility in practical medicine : an address read before the meeting of the Tunbridge Wells and neighbouring divisions of the British Medical Association / by Herbert French.

  • French, Herbert Stanley, 1875-1951.
Date:
1907
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Licence: In copyright

Credit: Opsonins and their utility in practical medicine : an address read before the meeting of the Tunbridge Wells and neighbouring divisions of the British Medical Association / by Herbert French. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    \ ON OPSONSSff BWJPT'HEIR UTILITY IN PRACTICAL MEDICINE. I DO not wish it to be supposed that what I have here to say about opsonins and the question of vaccine treatment of certain diseases is any original work of my own; the credit of the work belongs to Koch, Behring, Wright, Bulloch, Eyre, Louisson, and a host of other workers. It is to Sir A.. E. Wright that our present knowledge of opsonins is mainly due. What Opsonins Are. The white corpuscles of the blood can be kept alive outside the body; experiments can therefore be made with living leucocyes in test tubes and so on. Under the microscope the great Professor Metclmikoff watched such leucocytes engulting or swallowing up bacteria by a pro- cess which we all know by the name “phagocytosis.” Phagocytosis is at the bottom of all estimations of the opsonic index. Let me confine myself for the present to the phago- cytosis of tubercle bacilli. If living leucocytes in a test tube be incubated at body temperature along with a number of tubercle bacilli obtained from a cultivation of these organisms, a film can be made of the leucocytes upon a microscope slide, stained appropriately by the Ziehl-Nielsen method for tubercle bacilli, and examined under a microscope with a in. oil-immersion lens. It will be found that many of the tubercle bacilli are now inside the leucocytes, having been, so to speak, eaten by them. The number thus eaten up by 100 leucocytes can be counted. We shall all agree that the larger the number of tubercle bacilli taken up by 100 leucocytes in this way in a given time, the greater is the phagocytic power of those leucocytes for the tubercle bacilli in question. For instance, granted that the same cultiva- tion of tubercle bacilli be used in each case, and that the time and temperature of incubation be the same, if it be found that one set of leucocytes engulf 100 tubercle bacilli per 100 leucocytes, and another set engulf 200 tubercle [31/07]