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SummaryThe influence of pyridoxine, inositol, and biotin deficiencies on the susceptibility of mice to experimental poliomyelitis has been studied in more than 1400 animals. No striking or consistent difference with reference to susceptibility to either Lansing strain poliomyelitis or Theiler's encephalomyelitis was noted between animals fed diets deficient or optimum in these vitamins.

SummaryA practical meatless ration for trout containing 55% plant material is described which is essentially equivalent to a standard liver, canned carp diet so far as growth and hemoglobin levels are concerned.The effect of various substitutes in the ration is described.Although this ration contains 45% carbohydrate, liver enlargement was not noted except when sprouted soybeans or poor quality yeast were included. Large scale field trials indicated that Ration C was superior to pork spleen, and equivalent to pork spleen supplemented with canned carp, as a diet for yearling brook trout on the basis of both growth and mortality.

SummaryA method of obtaining electroencephalograms in dogs has been described. When rations which contained casein were fed no abnormalities were observed. After wheat gluten was substituted for casein epileptiform seizures and concomitant abnormalities in the E.E.G. developed which were comparable to those seen in cases of human epilepsy.

In several recent publications (14) it has been reported that dietary aminopterin produces a marked decrease in rat liver choline oxidase activity as measured by the whole homogenate technique. A simple folic acid deficiency, however, has been shown to produce only slight changes in the activity of this enzyme (5). It was probable that a simple folic acid deficiency did not deplete the tissues of folic (and folinic) acid to a great enough extent to produce much change in the activity of the whole homogenate. If only minute amounts of a folic acid cofactor were needed by the enzyme, a whole liver homogenate, even from deficient animals, might contain enough of the cofactor to maintain the normal activity of the enzyme. The choline oxidase system of rat liver has been shown to be located in the mitochondrial fraction of liver (6-S). Therefore, the authors felt that, if the mitochondria were isolated, washed, and thus freed of extraneous folic acid, folinic acid, or cofactor containing either of these in bound form, the effects of a simple folic acid deficiency could be demonstrated more clearly. In the present investigation not only the effect of a simple folic acid deficiency on the choline oxidase of isolated mitochondria has been studied, but also a comparison has been made with the effects on the mitochondrial activity of the enzyme produced by feeding aminopterin to rats. In order to complement the enzyme results, and to study the correlation of the eneyme activity with folic acid and folinic acid’ concentration in the tissues, all of the samples used for the enzyme determinations were assayed microbiologically for both folic acid and folinic acid. In the course of these

PEROSIS, an anatomical deformity of the leg bones of young chicks, was first described by Hunter and Funk (1930). The condition is associated with a high intake of calcium and phosphorus, and a low intake of manganese (Hunter et al., 1931; Milby, 1934; Wilgus et al., 1936–1937; Clifcorn et al., 1938). Later, the work of Wiese et al. (1939) showed that the blood and bone phosphatase activity of perotic birds was lower than that of chicks receiving an adequate amount of manganese in their diet. As the leg bones of chicks with perosis are bent and twisted from their normal shape it was thought that there might be an abnormal distribution of the enzyme phosphatase in the bones of these chicks. In this paper we wish to report the results we have observed on the distribution of this enzyme in the leg bones of perotic and normal chicks. EXPERIMENTAL

Studies in this laboratory on the relation of the level of fat, carbohydrate, and protein in the diet to the vitamin requirements of growing animals led to the observation that the feeding of high levels of fat to young rats increased the riboflavin requirement. Modifications of the basal riboflavin-low ration K21 described by Wagner, Axelrod, Lipton, and Elvehjem1 were utilized in studying this effect. Lard was isodynamically substituted for dextrin at two levels so that in ration K22 the total fat content was about 25% and in K23 about 40%. Choline was added to the extent of 5 mg per 100 g of K21, or its isocaloric equivalent in the other rations. Storage of the rations in the refrigerator and daily feeding prevented rancidity.In the first series albino rats weighing from 60 to 75 g were partially depleted of their riboflavin reserves by placing 12 rats on each of the above rations for a period of 4 weeks. Four animals in each group were then supplemented with 3γ of riboflavin per day, four, with 6γ of ...

Summary 1.The serum of winter produced milk showed physical characteristics at variance with that of summer produced milk. It was clarified with greater difficulty. An adjustment of the salt balance and pH improved somewhat the technique used for the preparation of the serum from winter milk. The time at which these changes occur varies from year to year. 2.The serum of winter produced milk showed lower nutritive value than that of summer produced milk as measured by its use in supplementing a highly purified diet as a source of the vitamin B complex. 3.The significance of these studies lies in the relation of fresh plant tissue as contrasted with field dried material to subtle changes in the milk secreted.

SummaryWhen the rate of growth of chicks is used to measure the nutritional efficiency of carbohydrates they fall in the following order: dextrin, cerelose, sucrose, and lactose. Cellulose, sulfasuxidine, reticulogen, fish solubles, or vit. B12 do not change the significant differences observed when these carbohydrates are fed. However, the lactose-fed birds do give the greatest response to reticulogen, fish solubles and the higher levels of vit. B12. The excretion times of chickens fed these different carbohydrates are in the following decreasing order: dextrin, sucrose, and lactose. The possibility of these nutritional differences being explained by the synthesis of known and/or unknown factors is discussed.

GRAHAM (1934) reported that the average level of protein intake was 12.9 percent when laying hens were fed an 18 percent protein laying mash plus corn and oats. Some birds laid well on a diet containing 12 to 13 percent protein while others required 14 to 15 percent protein. Nonlaying birds appeared to thrive and prepare to lay on an 11 percent protein diet. Heiman et al. (1936) studied the protein requirement of Single Comb White Leghorn pullets. These workers found that a 13 percent all-plant-protein diet would not maintain body weight. When fish meal was added to the diet, the marginal protein level for weight maintenance and egg production appeared to be 14 percent. Heuser (1936) reported that 16 percent dietary protein was optimal for laying hens. MacDonald (1938) reported that hens fed a diet containing 12.5 percent protein laid as well as hens receiving 15 percent protein. Carpenter . . .

MOORE et al. (1946) reported that the addition of streptomycin and sulfasuxidine to a purified diet brought about a growth response in chicks. The antibiotics did not cause a sterilization of the intestinal tract of chicks, but did produce a marked reduction in the coliform bacteria of the cecal contents. In 1947, Newell et al. reported that with a practical ration, combinations of dried penicillin mycelium and fish press water resulted in excellent growth of chicks. Later work by Cunha et al. (1949a), McGinnis et al. (1949) showed that an aureomycin mash A.P.F. concentrate was superior to vitamin B12 for swine and turkey poults. Stokstad et al. (1950) and Whitehill et al. (1950) reported the activity of the antibiotics in stimulating growth of chicks fed all vegetable type rations. Thayer et al. (1950) presented data which indicated that an A.P.F. concentrate has a sparing effect on the protein needs of . . .

Several studies have been carried out in this laboratory relating the xanthine oxidase activity in the liver of adult rats to the quality of dietary protein (Litwack et al., '52, '53c). The behavior of this enzyme toward fasting and pro tein and amino acid-deficient diets (Miller, '48; Seif ter et al., '48; Litwack et al., '50; Williams and Elvehjem, '49, '50; Williams, DentA3n and Elvehjem, '49) has been exten sively studied, as have the effects of non-specific ammonium nitrogen sources on the enzyme activity (Litwack, Williams and Elvehjem, '53b). In some of our previous work using adult animals (Lit wack et al., '52, !53c) we have described a method for evalu ating the quality of dietary protein, using the response in liver xanthine oxidase activity as the criterion. We have also tested the quality of various protein preparations, using this method. After studying the deficient protein, gliadin, and supplementation of this protein with amino acids, it was concluded that the enzyme response was very sensitive to

SummaryHigh oral intakes of folic acid are stored inefficiently in chick livers and have little if any effect on the content of this vitamin in chick muscle tissue. Chicks given large oral doses of folic acid and then placed on a folic acid-deficient diet grew as well as chicks receiving an equivalent amount of folic acid by injection. The distribution of folic acid in some representative chick tissues has been studied.