Albert G. Hogan

Vitamin B12, a Factor in Prevention of Hydrocephalus in Infant Rats.

Summary After female rats, on a diet that contained soybean oil meal as a source of protein, became depleted of the factor that prevents hydrocephalus, the incidence of the abnormality among the offspring was 28%. The addition of a vit. B12 concentrate to the diet or the injection of crystalline vit. B12 in the dams during the early stages of gestation prevented the abnormality in the young animals and increased their viability. Hydrocephalus was not prevented by folic acid alone, but it has not been determined whether vit. B12 alone is effective or whether both folic acid and vit. B12 are required.

Maternal nutrition and hydrocephalus in newborn rats.

Summary Female rats were supplied with an experimental diet that contained soybean oil meal as a source of protein, and a vitamin mixture that included all recognized vitamins except ascorbic acid, niacin, folic acid and B12. The incidence of hydrocephalus in the young was less than 1%. When folic acid antagonist was added to this diet the incidence of hydrocephalus rose to 20%. The type of diet consumed during the pre-experi-mental period determined the amount of time that elapsed, during the experimental period, before hydrocephalus appeared in the young.

A Hemophilia-Like Disease in Swine.

During the last few years a number of swine in the Missouri Agricultural Experiment Station† herd have died from hemorrhage, either spontaneous or as a result of minor wounds. All of the affected animals are closely related. It is evident that the blood-clotting mechanism is seriously defective, and a study was initiated in an attempt to classify the abnormality. Bleeding Time. If determined by Dukes method 1 the bleeding time is within the normal range. As shown in Table I though, if an incision of any extent is made the bleeding time is prolonged indefinitely. Coagulation Time. The procedure followed is essentially the same as the Lee-White 2 modification of Howells method. The blood sample is taken from an ear vein, collected in cold paraffin coated tubes, and placed in an ice bath. The results reported in Table I show that the coagulation time was 5 times that of normal blood. The blood clots slowly, but after it forms it retracts in normal time. According to the prevailing theory at least 4 components of the blood are intimately concerned with blood coagulation: (1) calcium; (2) prothrombin; (3) fibrinogen; (4) thromboplastin, which presumably is released from the platelets and other formed elements. Each one has been subjected to preliminary investigation. Calcium Time. According to our observations the calcium time 3 is not less than the coagulation time, and the serum calcium was shown by analysis to be well within the normal range. Our data on calcium are omitted from the tabulations. Fibrinogen Content. Oxalated plasma was diluted with isotonic saline and recalcified. The resulting fibrin was removed and determined quantitatively. The data shown in Table II indicate that the blood of defective animals contains slightly less fibrinogen than does that of normal controls, but the quantity is more than enough to form a normal clot.

Relation of folic acid and vitamin A to incidence of hydrocephalus in infant rats.

Summary About 20% of the young rats weaned from dams fed a synthetic type diet deficient in folic acid developed hydrocephalus. This abnormality could be largely prevented by the addition of pteroylglutamic acid to the maternal diet. Decreasing the vitamin A content of the diet to a low level did not increase the incidence of the hydrocephalus. There was no difference in either the moisture content of the brains or in the cerebrospinal fluid pressure of rats from the stock colony and those from dams receiving a synthetic type ration.

Plural Nature of Vitamin B

ONE group of rats was supplied with vitamin B carriers that had been subjected to intense ultraviolet irradiation. The animals developed a severe dermatitis and died. A second group received tikitiki, an alcoholic extract of rice polishings, as the sole source of vitamin B. After some ten or twelve weeks these rats became denuded, assumed a very miserable appearance, and finally they died also.

Effect of a high phosphorus diet on acid-base balance in guinea pigs.

Summary Injurious effects of high phosphorus diets for the guinea pig, which include poor growth, metastatic calcification, and death, are due in part to the fact that this animal does not tolerate an acid diet. This has been demonstrated by the marked drop in urine pH, a decrease in plasma carbon dioxide capacity and an increase in blood inorganic phosphorus. Addition of various cations produced a more alkaline urine, but a combination of sodium or potassium and magnesium proved most beneficial. The guinea pig is highly sensitive to an acid diet because a negligible amount of ammonia is excreted by way of the kidneys.

Effect of Thiouracil on Growing Swine.

Summary 1. Four groups of swine were pair-fed on rations which were identical except for the addition of 0.2% thiouracil to the ration of the test animals. 2. The test animals were less active, and after 28 days they were shorter and fatter than the controls. They gained weight more rapidly and more economically than did the controls.

The Number of Vitamins Required by the Rat.

During their studies of rat dermatitis Richardson and Hogan 1 observed that rats which receive only the recognized water-soluble vitamins are able to survive for long periods of time, and to maintain a moderate rate of growth. Four of the 8 females described in Groups III and IV, Table I. of the report cited, attained an average weight of 176 g in 20 weeks, when it became necessary to discard them. The ration was then changed in various ways in an attempt to secure a more rapid growth rate and 3 of the more important modifications are described in Table I. The response of the animals is shown in Fig. 1. It will be observed that Ration B contains no added fat, but it was supplemented with 10 mg of linoleic acid daily per rat. Ration A contains no added fat except the 2% of cod liver oil. Since neither ration supplies the quantity of fatty acids that is necessary for a normal rate of growth, even if the vitamin supply is adequate, a ration was prepared which contains additional fat. Ration C contains 8% of lard, also a more generous allowance of the water-soluble vitamins. In all 14 male and 5 female rats have received this ration and up to the present their growth rate is about the same as that of rats in the stock colony. Three males, Nos. 7385, 7391, 7392, Fig. 1, attained an average weight of 368 g in 18 weeks. They are in excellent condition and heavier than stock colony males of the same age. Each of them has sired 2 normal litters. Jukes 2 reported that a ration which contains no water-soluble vitamins, other than those now recognized, will permit female rats to attain maturity and bear litters. However, his animals grew at a subnormal rate and reared only a small proportion of their young. The minimum amounts that will maintain normal growth have not been determined, but it is our experience that when the water-soluble vitamins are supplied at the levels commonly employed the growth rate is suboptimal. When choline was omitted from Ration C the growth rate was severely depressed. When omitted from Ration A the growth rate was unchanged.

The antithyrotoxic factor: Its splubilization and relation to intestinal xanthine oxidase☆

Abstract 1. 1. The major portion of the antithyrotoxic factor in liver and soybean meal is not extractable with water, but the factor becomes water soluble upon hydrolysis with proteolytic enzymes, sodium hydroxide, or sulfuric acid. 2. 2. Although molybdenum produces the saturation level of intestinal xanthine oxidase activity in normal rats fed a casein-type diet, in the hyperthyroid rat it gives values of about two-thirds of those obtained with liver residue. 3. 3. The correlation between the growth of rats fed iodinated casein and the level of intestinal xanthine oxidase activity suggests that the antithyrotoxic factor may be required to give maximum xanthine oxidase activity when the animal is under stress.

Adequacy of synthetic diets for reproduction of swine.

Summary Two sows which consumed synthetic diets and were given injections of approximately 400 μg each of vit. B12 reared their first litters. The weights of the pigs when weaned at 8 weeks were subnormal, 20 and 26 lbs., and there were other signs of mild nutritional deficiency. One of the sows received by injection 2,380 μg of the vitamin during a second gestation and lactation and reared a litter of 7 pigs with the unusual average weaning weight of 47 lbs. The other sow consumed during her second gestation and lactation a diet that contained a water extract of liver and weaned a litter of 7 with an average weight of 35 lbs. The inclusion of a liver extract in the synthetic diet was not more effective than was the injection of vit. B12 and the evidence indicates that swine can complete a normal life cycle on diets that contain no unrecognized nutrients.