C. Charlton Mabry

Leucine-induced hypoglycemia

Summary Two infants with leucine-sensitive hypoglycemia are presented. A standard intravenous leucine tolerance test has been devised and utilized in the study of these 2 infants and of euglycemic and other hypoglycemic children who were not leucine sensitive. The leucine-sensitive children consistently had a decline in blood sugar levels of greater than 50 per cent 20 to 40 minutes after administration of the leucine. The diagnosis of leucine-sensitive hypoglycemia and management of infants who have it are discussed.

Leucine-induced hypoglycemia. I. Clinical observations and diagnostic considerations.

Summary Two infants with leucine-sensitive hypoglycemia are presented. A standard intravenous leucine tolerance test has been devised and utilized in the study of these 2 infants and of euglycemic and other hypoglycemic children who were not leucine sensitive. The leucine-sensitive children consistently had a decline in blood sugar levels of greater than 50 per cent 20 to 40 minutes after administration of the leucine. The diagnosis of leucine-sensitive hypoglycemia and management of infants who have it are discussed.

Leucine-induced hypoglycemia: II. Studies concerning other amino acids and leucine metabolites*

Summary Two infants with leucine-sensitive hypoglycemia have been studied to elucidate the specificity and mechanism of action of l -leucine. Sixteen other naturally occurring l -amino acids have been administered intravenously and tyrosine and tryptophan by gavage. Of these amino acids, only l -leucine consistently induced hypoglycemia. d -leucine also produced hypoglycemia when given intravenously. Alpha-ketoisocaproic and isovaleric acids were administered intravenously; the former induced hypoglycemia whereas the latter did not. Monocarboxylic keto-acids in the urine were measured following l -leucine or alphaketoisocaproic acid loading. The recovery of keto-acids in the urine was of a low order, similar to that of a control subject indicating no metabolic defect in the conversion of alpha-ketoisocaproic acid to isovaleric acid. Preliminary evidence is presented that leucine administration to affected patients results in increased circulating insulin levels.

LEUCINE-INDUCED HYPOGLYCEMIA. III. THE BLOOD GLUCOSE DEPRESSANT ACTION OF LEUCINE IN NORMAL INDIVIDUALS.

The administration of l -leucine to leucine-sensitive children produces profound hypoglycemia. The effect of l -leucine on the blood glucose concentration of normal individuals has been studied. A small but definite effect has been found which suggests that a homeostatic relationship between the amino acid and insulin exists. This relationship is abnormal in the children with leucine-sensitive hypoglycemia.

Original articleTrismus pseudocamptodactyly syndrome: Dutch-Kentucky syndrome†

A hand, foot, and mouth combination of anomalies, which is apparent on motion, has been traced through eight generations of a southern Appalachian family. The clinical features from birth to old age are presented, and attention is called to the handicapping aspects. There is a great variability in severity of the trait. Inheritance occurs as an autosomal dominant trait, but there are fewer affected persons than expected, especially females.

Prolonged neonatal anoxia without apparent adverse sequelae

Summary 1. An infant is reported who survivedprolonged anoxia for at least 15 and probably for 30 minutes and in whom harmful sequelae are not apparent at the age of 20 months. This period of “total anoxia” is longer than has been previously reported in surviving infants. 2. The mechanisms which permit the newborn infant to survive prolonged periods of anoxia are discussed.