P. B. Pearson

Histological manifestations of a magnesium deficiency in the rat and rabbit.

Summary Low levels of magnesium in the diet of rabbits and rats produced chromatolysis and degeneration of the cells of Purkinje of the cerebellum in the rat and rabbit. Nephrosis and fibrosis of the kidney occurs in rabbits restricted to a diet deficient in magnesium.

The pantothenic acid content of royal jelly.

Summary It has been found that royal jelly is the richest known source of pantothenic acid. On a dry basis it contains an average of 511 μg per g which is between 2.5 and 6 times as much pantothenic acid as is present in yeast or liver.

Value of urea in the diet of rabbits.

Summary The addition of urea to a diet low in protein did not increase the rate of gain of rabbits. From the data it is apparent that this species cannot use urea in the diet as a replacement of part of the protein. Rabbits fed diets containing 10% of casein as the sole source of protein or 10% casein plus 3.43% urea developed typical vitamin A deficiency symptoms as compared with the control group fed a diet similar except that it contained 20% of casein. The results suggest that protein has a protective action on the oxidation of vitamin A in the diets or that it has a sparing action on the vitamin A requirements of the rabbit.

Metabolic fate of S35-labeled sulfate in baby pigs.

Summary The metabolic fate of S35 administered by stomach tube as sulfate to baby pigs has been studied. About 62% of the dose was excreted in urine within 4 days. Of tissues analyzed, ear cartilage, red bone marrow and aorta showed highest concentrations of S35 and brain and muscle lowest concentrations, 4 days following dosing. About half of the S35 in intestinal tract contents was in organic form, while only very small amounts of organic-S35 were detected in tissues examined.

Effect of a pellagra-producing diet on herbivora.

Summary Lambs developed normally on a ration that causes cessation of growth and produces pellagra-like symptoms in pigs and black tongue in dogs. From this it appears that nicotinic acid is either not a dietary essential for this species or that the requirements are much lower than for the pig, dog, or human.

Toxicity of choline in the diet of growing chickens.

Summary Various levels of choline chloride were added to rations fed to growing chickens. The addition of 1%, 2% and 4% reduced the rate of gain by about 12%, 13.8% and 23.8% respectively. As much as 4% of choline chloride added to the diet produced no toxic manifestations other than retarded growth.

Pantothenic Acid Content of Pollen.

Summary Pollen samples have been assayed for pantothenic acid and found to contain an average of 30.3 pg per μg on a dry basis. There is evidence that the pantothenic acid content of pollen varies with different plant species.

Magnesium Deficiency in the Sexually Mature Rat.

Summary Sexually mature rats maintained on a magnesium-deficient diet develop lesions of the skin characterized by erythema, purpural hemorrhages and eschars. The addition of magnesium to the diet results in recovery from the skin lesions. Other symptoms observed are essentially the same as in the immature animal deprived of magnesium. The increased length of time before the appearance of symptoms in older animals probably reflects increased body stores of magnesium with an increment in the time required to deplete the tissues of this element.

Occurrence of conjugase in egg yolks.

Summary Evidence is presented to show that chicken and turkey egg yolk contain a conjugase which liberates PGA from these materials. A synergistic action of egg yolk conjugase and chick pancreas is required in order to obtain the total PGA in egg yolk of chickens and turkeys. The liberation of microbiologically available PGA from egg yolk by the combined action of egg yolk conjugase and chicken pancreas conjugase gives a total PGA value which approaches the value obtained by the chick assay for this vitamin. An inhibitory effect of autoclaved chick pancreas on the conjugase of chicken egg yolk is indicated by the results.

Effect of Liver Extract on Growth of Rabbits.

Summary The addition of 4% 1:20 liver concentrate to purified rations increased the rate of growth and aided in the maintenance of a general healthy appearance of rabbits. The improved performance noted when liver extract was added is apparently not attributable to known nutrients including folic acid, biotin, p-aminobenzoic acid and cystine. The results indicate that liver contains an unidentified factor essential for the maximum rate of growth of the rabbit.