Parenteral absorption of insulin from the lung in diabetic children.

Semi-synthetic human insulin was delivered via a novel nebulizer to the respiratory tracts of six diabetic children. Blood glucose control obtained was at least as good as a control day when they received their usual dose of subcutaneous insulin.

A comparison of ritodrine, terbutaline, and magnesium sulfate for the suppression of preterm labor.

Ritodrine, terbutaline, and magnesium sulfate have all been used in the United States as tocolytic drugs. Studies have shown each of these drugs to be effective in suppressing preterm labor. The current study was undertaken in order to compare their relative safety and efficacy and to evaluate the effectiveness of a second drug when the first-used drug failed to stop contractions. No differences in efficacy could be demonstrated between the drugs; however, there was a marked difference in the incidence of maternal side effects. Because of an unacceptable level of side effects, we have stopped the use of terbutaline at our institution.

Studies of insulin-like growth factor -I and -II by specific radioligand assays in umbilical cord blood.

Somatomedin concentrations in human umbilical sera (n = 206) were measured using a specific radioimmunoassay for insulin-like growth factor (IGF)-I and a specific radioreceptor assay for IGF-II following acid-ethanol extraction of the sera to remove the somatomedin binding proteins. IGF-I concentrations were lower (P less than 0.001) than adult values and correlated with gestational age (P less than 0.001) and birth weight (P less than 0.0001). Multiple regression analysis demonstrated that both birth weight expressed independently of gestational age as the standard deviate score (P less than 0.0001) and gestational age (P less than 0.002) had effects on umbilical cord IGF-I concentrations. IGF-II concentrations were similar to adult values and did not correlate with gestational age, birth size or IGF-I values. IGF-II concentrations were higher (P less than 0.005) in male than female fetuses. These data support a role for IGF-I in influencing fetal growth and suggest the independent regulation of the secretion of IGF-I and II in the perinatal period. These was no evidence to suggest a distinct perinatal form of somatomedin.

Neonatal screening for cystic fibrosis, using immunoreactive trypsin assay in dried blood spots.

Our previous studies suggested that assay of immunoreactive trypsin (IRT) in dried blood spots might be a valuable neonatal screening test for cystic fibrosis (CF). We have developed a convenient, sensitive, human trypsin radioimmunoassay, which uses a 3-mm diameter disc of dried blood. The molecular species assayed in blood is trypsinogen. A retrospective study of 24 known cases of CF and appropriate controls confirmed that an elevated blood level of IRT is characteristic of all newborn CF infants, whether or not they have residual exocrine pancreatic function. IRT levels did, however, decline with time of sample storage. Guthrie cards from 5040 newborns were prospectively assayed: 2% of tests were reassayed because of elevated IRT. Thirty-three second samples (0.67% of the total) were requested, 32 were received, and 31 had normal IRT values. The baby with an elevated result had no clinical symptoms of CF at one month of age, normal stool trypsin activity, but 2 sweat tests gave grossly abnormal results. In contrast, a second infant in whom CF was diagnosed around the same time, had a similar 5-day blood spot IRT value, but severe clinical symptoms of CF and no stool trypsin activity. No false negatives are yet known. We conclude that blood spot IRT assay is a reliable and convenient neonatal screening test for CF.