V. Feleki

Food Restriction and Lipogenesis in the Rat.

Summary 1. Using young male rats fed chow for only 2 hours daily, the increased lipogenesis in vitro and liver glycogen concentration reported by others has been confirmed. The phenomena have been demonstrated also in young male rats fed a purified, high carbohydrate diet for only 2 hours daily. 2. In contrast to the findings of Hollifield and Parson, young rats whose feeding time was restricted to 2 hours daily had a lower food intake and body weight gain than did ad libitum-fed controls whether provided with chow or the high carbohydrate diet. These “restricted” animals had slightly lower proportion of carcass fat and higher proportion of water and ash. 3. Adult male rats when provided with the high carbohydrate diet for only 2 hours daily, ate less than ad libitum-fed controls and failed to gain weight.

Effect of Exercise on Coronary Tree Size in the Rat

Using the vinyl acetate corrosion cast technique devised by Tepperman and Pearlman, it has been demonstrated that, in the rat, forced physical exercise (treadmill or swimming) causes an increase in apparent coronary tree size provided the exercise is not too strenuous or frequent.

Metabolic Changes in Alzheimer's Disease

Patients with Alzheimers disease (AD) and matched controls fasted for 24 hours, and serial glucose, pyruvate, lactate, β‐hydroxybutyrate, acetoacetate, insulin, and glucagon levels were measured. Patients with AD showed a glucose insulin correlation pattern over the 24 hours that differed from the control group. These differences may be secondary to weight loss or to other metabolic or nutritional factors affecting the AD patients.

Acid hydrolases in the serum and liver in mucopolysaccharidoses types I and III

Summary 1. Results of the assay of several acid hydrolases in the serum and liver of control children and patients with types I and III mucopolysaccharidoses (Hurler and Sanfilippo syndromes) are described. 2. The activity of β-N-acetylglucosaminidase, β-glucuronidase, and aryl sulfatase A was elevated in the serum of patients with both types I and III disease. Serum acid phosphatase activity was depressed in type I patients. 3. Activities of α-mannosidase, α-fucosidase, β-N-acetylglucosaminidase, β-glucuronidase, hyaluronidase, and acid phosphatase were increased in the liver from patients with type I disease. In the liver from patients with type III disease activities of all of the above enzymes except acid phosphatase, and in addition aryl sulfatase A were elevated.

Tay-Sachs disease: B1 variant

This first child of non-Jewish parents had nystagmus at 4 months of age, bilateral cherry-red macular spots at 7 months of age, and hyperacusis at 8 months of age; the patient has deteriorated progressively following a clinical course typical of Tay-Sachs disease B variant. Total beta-N-acetylhexosaminidase assayed with 4-methylumbelliferyl-beta-glucosamine (4 MU GlcNAc) as substrate was within the normal range in plasma and cultured dermal fibroblasts and 2/3 the normal mean in leukocytes. The hexosaminidase A activity, assayed with the same substrate in plasma and cultured fibroblasts, approximated Tay-Sachs disease heterozygote levels; however, the activity of hexosaminidase A assayed with 4 MU Glc NAc-6-sulfate in the plasma, leukocytes, and cultured fibroblasts was less than 8, 2, and 1%, respectively of the control mean. This female infant with the B1 variant of Tay-Sachs disease demonstrated an earlier onset and more rapidly progressive course than was observed in 4 of the 5 previously reported patients with this Tay-Sachs disease variant.

Defective heparan sulfate metabolism in the Sanfilippo syndrome and assay of this defect in the assessment of the mucopolysaccharidoses patient

The Sanifilippo syndrome is an inherited dementia caused by defective degradation of heparan sulfate. In the course of its catabolism the heparan sulfate polymer must be desulfated. Heparan sulfate sulfatase activity was demonstrated in homogenates of normal tissues and cultured skin fibroblasts, and in normal urine. This activity was found to be grossly depressed or absent in necropsy specimens of liver and spleen from two Sanfilippo patients. The heparan sulfate sulfatase activity was not demonstrable in urine from eleven, or cultured fibroblasts from four Sanfilippo patients. Activities of alpha-N-acetyl-glucosaminidase, the site of the metabolic defect in the Sanfilippo B variant were either normal or slightly elevated in the Sanfilippo tissues and cultured fibroblasts whereas the mean level in the urine of our Sanfilippo patients was about one-third of that encountered in control urines.