Charles C. Lobeck

Metabolism of tritiated vitamin D3 in familial vitamin D-resistant rickets with hypophosphatemia†

The metabolism of tritiated vitamin D 3 in two control subjects and two with familial vitamin D-resistant rickets was studied. Sixteen hours after a 0.25 mg. intravenous dose of H 3 vitamin D 3 was given, blood samples were taken, extracted, and chromatographed. Both control and rachitic subjects produced in similar amounts a major, polar, biologically active metabolite previously discovered in rats. They also produced another minor chloroform soluble metabolite and aqueous soluble metabolites. Rachitic subjects retained about 60 per cent of the administered dose in blood after 16 hours, while controls retained only 20 per cent. The rachitic subjects had about 20 times more aqueous soluble metabolites in their blood than did the normal ones.

Response of sweat electrolyte concentrations to 9 alpha-fluorohydrocortisone in patients with cystic fibrosis and their families

Parents and siblings of patients with cystic fibrosis were found to have decreases in concentrations of sweat sodium and chloride proportionate to those of control adults and children after the administration of 3.0 mg. per square meter of 9-alpha-fluorohydrocortisone for 2 days. Thus the heterozygous state was not detected. Patients with cystic fibrosis, including 1 adult, showed no significant decrease in these sweat electrolytes with the same challenge. This lack of response to corticosteroids could be used to confirm the diagnosis of cystic fibrosis in adults since abnormally high sweat electrolyte concentrations are more difficult to detect in this age group.

Study of sweat in pitressin-resistant diabetes insipidus

Increased sweat electrolyte concentrations, sodium 60 to 70 mEq. per liter, chloride 50 to 60 mEq. per liter, potassium 15 to 20 mEq. per liter were observed in a 41/2-month-old child with pitressin-resistant diabetes insipidus who initially did not exhibit excessive thirst. Administration of large doses of 9 alpha-fluoro-hydrocortisone did not affect these values. Hydrochlorthiazide therapy was associated with immediate clinical improvement and marked decrease in sweat sodium and chloride concentrations. Hydrochlorthiazide caused clinical improvement despite increased urine volume during therapy. All observations of elevated sweat electrolytes in pitressin-resistant diabetes insipidus have been in infants less than 10 months of age and not solely in infants without excessive thirst. Therefore sweat analysis may be an aid to diagnosis in infants when clinical recognition is difficult.

Can Pediatrics Contribute to Geriatrics

T he recent historical commentary by J. C. Beck’ suggests that pediatrics and geriatrics should have a common academic interest in the process of aging. Similarities do not end with the fact that they deal with the limits of life. This commentary compares and contrasts characteristics of the two disciplines against the background of their origins, and suggestion is made that communication and comparisons between the two disciplines might be advantageous to both. As was discussed by Beck, geriatrics and pediatrics have differing beginnings. There has been medical concern about child rearing and the diseases of children2 since earliest times, but not until the 19th century in the western world, were these interests perceived to have unique value to society. The industrial revolution and the ensuing child welfare movement were associated with improvement in hygiene and rising interest in scientific child care. In the United States, pediatrics began in the university. Its founder, Abraham Jacobi (1830-1919), held the first chair of pediatrics in a medical school, was the first president of the American Pediatric Society, and founded the pediatric section of the American Medical Association. His influence and that of his colleagues resulted in observations and then experiments which brought science to the prevention and treatment of childhood disease. It also resulted in the development of pediatrics as an academic discipline at the Johns Hopkins University School of Medicine in the early part of this century. Very quickly, rickets and other deficiency diseases, diarrhea, pneumonia, and many contagious diseases were understood and the means of their control made available. During the past 20 years there has been a dramatic decrease in the hospitalization of A

Radioautographic localization of the acetylcholine-stimulated synthesis of phosphatidylinositol in skin from patients with and without cystic fibrosis.

Abstract The distribution of radioautographic grains over various regions of human skin tissue was investigated after incubation of skin tissue slices for 2 hours in the presence of myoinositol-2- 3 H with and without acetylcholine plus eserine. Skin tissue was obtained from control patients and from patients with cystic fibrosis, an inherited disease in which there is a defect in the function of all the exocrine glands, including the eccrine sweat gland. After incubation the skin slices were fixed in neutral formalin, washed in tap water, and embedded in a water-soluble wax (Carbowax). They were then sectioned and prepared for radioautography. Under these conditions only water-insoluble phosphatidylinositol (PI) should be radioactive. Labeling was found in the duct portion of the eccrine sweat gland as well as in hair follicles, epidermis, and some dermal areas when skin slices were incubated in the presence of myoinositol-2- 3 H. It was randomly distributed throughout the cytoplasm of the cells; no nuclear labeling was seen. Only the duct region consistently gave a statistically significant increase in labeling when skin slices were incubated in the presence of myoinositol-2- 3 H plus acetylcholine plus eserine. No labeling was found in the coil region of the eccrine sweat gland after incubation in the presence of myoinositol-2- 3 H with or without acetylcholine plus eserine. No difference in the amount or distribution of label was observed between patients with cystic fibrosis and controls. Extraction of incubated tissue sections from control patients with both acidified and nonacidified chloroform: methanol prior to radioautography resulted in nearly complete removal of the labeling. In two of the three patients with cystic fibrosis, however, acidified chloroform: methanol was much more effective in removing label than was nonacidified chloroform: methanol. The possibility that the phosphatidylinositol effect found in the duct region of the eccrine sweat gland is related in some manner to the secretion and transport of ions and/or other materials across the duct is discussed.

Pediatrics in Perspective

Assessments of the state of pediatrics have been frequent in recent years.1–3 Most commentators see the discipline forced into new directions by its past successes, new problems, and societal demands, and are concerned by the immediate problems of the future. Few have analyzed the roles of pediatricians as they have changed or have recognized the growing behavior of pediatricians in contemporary society as major reformers of child health practices.