A Contribution to the Knowledge of the Properties of Mixtures of Diphtheria Toxin and Antitoxin with Diphtheria Formol Toxoids and of the Application of These Properties for the Measurements of Toxoids

Perry, Vida Johnston (1934) A Contribution to the Knowledge of the Properties of Mixtures of Diphtheria Toxin and Antitoxin with Diphtheria Formol Toxoids and of the Application of These Properties for the Measurements of Toxoids. PhD thesis, University of Glasgow.

Abstract

The possibility of rendering toxic a non-toxic toxin-antitoxin mixture by the addition of toxoid is confirmed. The more antitoxin the mixture contains, the greater must be the amount of toxoid added in order to render the mixture toxic. When the excess of antitoxin is too great it is technically impossible to bring together the necessary amount of toxoid with the toxin and antitoxin in a volume that would allow of subcutaneous injection of a guinea pig. Time has an influence on the dissociative action of toxoids. Under otherwise similar conditions the difficulty of rendering toxic a non-toxic toxin-antitoxin mixture by means of the addition of toxoid becomes greater, the longer the toxin-antitoxin mixture has stood. This influence exerted by time is particularly noticeable when the serum is fresh. It may be assumed that fresh sera show a greater avidity towards toxin than do old sera which have been in stock for some time. In the dissociative action of toxoid on toxin-antitoxin mixtures the temperature at which the binding process takes place plays a part; if for example, under similar conditions with regard to time, toxin-antitoxin mixtures are placed at varying temperatures it is found that the binding power of the toxin and antitoxin increases with the rise in temperature, so that the higher the temperature at which the mixture stands the greater must be the amount of toxoid that has to be added in order to render the mixture toxic, assuming of course that the temperature is not such as would injure or destroy the toxin-antitoxin content. If when at a temperature of 40 C. one exposes a neutral toxin-antitoxin mixture to the dissociative action of toxoid, then the following is seen. The amount of toxoid which, ceteris paribus, is capable of rendering the mixture toxic increases up to the point where flocculation sets in. If the floccules are separated from the fluid and after washing in saline solution are resuspended, then it is possible by the addition of toxoid to render toxic both the floccule suspension and the supernatant. The toxin-antitoxin compound which is bound to the floccules can again pass into the surrounding fluid where it can be demonstrated by means of toxoid. To what extent this is possible depends on factors which are to be found in the individuality of the given toxins and sera. Time and temperature also play a part, higher temperature and a prolonged period of time for the action of the components on each appear to make the union a firmer one. In the measurement of a toxoid the Lf value alone does not give a complete picture of its antigenic action, for this method refers only to the binding power of the toxoid, while the other methods the Lb, Lba and Lbp which have been discussed in this work, allow of the determination not only of the binding power but also of the affinity of a toxoid to an antitoxin. The affinity can be expressed thus R = Lbp/Lba The lower the value of R is, then the stronger is the affinity of the toxoid to the antitoxin. If in a neutral toxin-antitoxin mixture or in mixtures of varying degrees of over-neutralisation, one knows the amount of toxin used in the production of the given mixture, then through dissociation of the compound by means of toxoid one is able to find how much antitoxin per cc. is present in the mixture.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Medicine, Immunology
• Date of Award: 1934
• Depositing User: Enlighten Team
• Unique ID: glathesis:1934-80026
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 03 Mar 2020 10:06
• Last Modified: 03 Mar 2020 10:06
• URI: https://theses.gla.ac.uk/id/eprint/80026