The experimental production of deafness in young animals by diet / by Edward Mellanby.

  • Edward Mellanby
Date:
[1938?]
Catalogue details

Licence: In copyright

Credit: The experimental production of deafness in young animals by diet / by Edward Mellanby. Source: Wellcome Collection.

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    the arteries entering the skull by bony occlusion. To what extent pres¬ sure and stretching caused by bone overgrowth is responsible for other widespread nerve degeneration previously reported in these animals is not yet clear. The addition of a source of vitamin A or carotene to the above diets prevents all these changes. Also, if the cereal portion of the diet is replaced by potato, even without the addition of extra vitamin A or carotene, the bones and nerves of the labyrinthine capsule are much less affected. Whether these changes in dogs above described have any bearing on the problem of deafness in human beings cannot be stated. It is clear, however, that both the bone overgrowth and the nerve degenera¬ tion are much more easily produced in young animals than in adults by these nutritional defects. Emerson, O. H. (Berkeley). The structure of beta and gamma toco- pherols. On oxidizing beta and gamma tocopherol with chromic acid, the same C21H40O2 lactone was obtained that had previously been obtained by Fernholz by the oxidation of a-tocopherol. Pyrolysis of gamma-toco¬ pherol yielded pseudo cumo hydroquinone. Hence, beta and gamma toco¬ pherol differ from alpha only in the absence of one of the methyl groups attached to the aromatic ring. Mattill, H. A. (Iowa City). Vitamin E and nutritional muscular dy¬ strophy in rabbits. Several investigators have stated that the muscular degeneration first demonstrated by Goettsch and Pappenheimer1) in young rabbits on i rations containing lard and especially cod liver oil is not preventable j by including various vegetable oils in the diet. Even wheat germ oil, •, which is rich in Vitamin E, is by itself not adequate to prevent the : disease, according to Morgulis and Spencer2); another factor, found in i wheat germ, lettuce and alfalfa, must also be present for prevention c or cure. The recent observation of McCay, Paul and Maynard3), that S hydrogenated cod liver oil in a natural grain diet produces no ill effects 3 suggests that auto-oxidation of the unsaturated fatty acids may, in¬ directly, be the principal/cause of the disorder. Vitamin E is known a to be destroyed quickly in the presence of readily auto-oxidizable i animal fats. When an efficient antioxidant is included in a synthetic diet (? containing no sources of Vitamin E, animals succomb as rapidly as on ] the basal diet alone. The presence of 2 % of wheat germ oil in the basal j diet has, in our experience, been adequate to prevent the disease for r< many months, during which the animals grew normally. Thus far, i
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