Mary F. Paul

The effect of mineral oil on food utilization II. Changes of beta-carotene in mineral oil

On the basis of the experiments reported here, stereoisomerization of beta-carotene is believed to occur both in vitro and in vivo in the presense of mineral oil. The lower biological activity of the stereo-isomers may account in part for the deleterious action of mineral oil on carotene utilization.

Effect of pH and of urea on nitrofurantoin activity.

Summary and conclusions 1. The apparent antibacterial activity of nitrofurantoin (pKa 7.2) against E. coli, S. aureus, and Pr. vulgaris is increased as the pH of the medium is lowered. 2. P. aeruginosa becomes susceptible to nitrofurantoin in the presence of 1% or more urea and in an acidic medium (pH 6). 3. Incorporation of 2% NH4Cl as a urinary acidifier in the diet of rats did not have a major effect on the nitrofurantoin concentrations attained in the urine or on the total amount of nitrofurantoin excreted. 4. The ingestion of a high protein diet by albino rats to increase urea excretion did not adversely affect the urinary concentration nor the total amount of nitrofurantoin excreted. S. Albino rats receiving 0.1% nitrofurantoin (about 10 × calculated human dose) and 2% NH4Cl in the diet for a 2-week period showed no evidence of crystalluria or kidney pathology.

THE EFFECT OF MINERAL OIL ON FOOD UTILIZATION I. CALORIC VALUE OF FOOD

Food consumption records and fecal weight data have been obtained on albino rats receiving diets with and without mineral oil. These data indicate that, at the levels of mineral oil studied, no caloric loss of food is experienced with the ingestion of mineral oil since: The levels of mineral oil studied were comparable on the basis of food consumption to doses of medicinal mineral oil commonly prescribed for the relief of constipation in humans.

Anaerobic loss of endogenous glycogen in rat heart slices.

Summary An anomalous situation has been encountered in a study of the endogenous carbohydrate metabolism of heart. It is believed that this anomaly, the failure of lactic acid to accumulate during anaerobic glycogen breakdown, my reflect the operation of an alternate pathway.

The effect of mineral oil upon fecal consistency, fecal bulk, and velocity of gastro-intestinal transport

Objective studies have been conducted on experimental animals to determine the results of mineral oil ingestion which may explain its value as a laxative. Laboratory methods have been described.