Abstract
LONDON. Royal Society, February 20.—Sir J. J. Thomson, president, in the chair.—S. S. Zilva and E. M. Wells: Dental changes in the teeth of the guinea-pig produced, by a scorbutic diet. The structure of the teeth of guinea-pigs subsisting on a scorbutic diet undergoes radical changes. The ultimate change is characterised by the total disorganisation of the pulp, including the odontoblastic cells. The earliest modification is observed at a period when no other systemic abnormality can be recorded with certainty, and is characterised by the alterations in the odontoblastic cells and by the dilatation of the blood-vessels of the pulp. Monkeys' teeth are also affected when these animals exist on a scorbutic diet. The bearing of the above results on human subjects is discussed.—W. E. Bullock and W. Cramer: A new factor in the mechanism of bacterial infection. The bacteria of gas-gangrene (B. welchii, Vibrion septiquie, and B. oedematiens) and of tetanus, when completely freed from their toxins, either by washing or by heating to 80° for half an hour so that spores are formed, do not produce the specific disease when injected into a mouse or a guinea-pig. The normal animal disposes of the bacteria mainly by lysis, and partly also by phagocytosis, and this defensive mechanism is so efficient as to render these bacteria non-pathogenic when injected by themselves. If a small dose of a soluble, ionisable calcium salt is injected together with the bacteria of their spores, the specific disease is elicited in a very virulent form. The chlorides of sodium, potassium, ammonium, strontium, and magnesium, when injected together with B. welchii, are not capable of producing gas-gangrene. From these experiments and other experimental evidence the conclusion is drawn that calcium salts, when injected subcutaneously, produce a local change in the tissues at the site of injection. The effect of this dosage is to bring about a local breaking down of the defensive mechanism against the bacteria of gas-gangrene and tetanus. The term “kataphylaxis” is proposed to designate this new phenomenon. Sterile watery extracts of earth are capable of producing this phenomenon.—Major W. J. Tulloch: The distribution of the serological types of B. tetani in wounds of men who received prophylactic inoculation, and a study of the mechanism of infection in, and immunity from, tetanus. In.a previous communication to the Royal Society it was shown that B. tetani was susceptible of classification into a number of groups differing one frorn another in their serological reactions. As this, finding might have an important bearing on the preparation of anti-toxin, as many strains of B. tetani as possible were investigated by the agglutination method: (i) from cases of the disease; (ii) from wounds of men showing no evidence of tetanus. The results obtained show that Type I. bacilli are but relatively infrequently obtained from wounds: of inoculated men suffering from tetanus. Thus 19 out of 25 (76 per cent.) strains obtained from the wounds of men who showed no evidence of tetanus proved to be Type I. bacilli, while 41 per cent. of the strains obtained from men suffering from the disease proved to be of this type. This observation suggested that there was possibly a mono-typical immunity to each serological type, for the serum used for prophylaxis was prepared mainly from the products of Type I. bacilli. Experiments show that mono-typical anti-toxin neutralises the toxins of all the types. The precise quality, as well as the degree, of tissue debility produced by injury is of importance in initiating the process of infection in tetanus.
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Societies and Academies . Nature 103, 17–19 (1919). https://doi.org/10.1038/103017a0
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DOI: https://doi.org/10.1038/103017a0