Developmental and genetic regulation of human surfactant protein B in vivo.

Background: Genetic and developmental disruption of surfactant protein B (SP-B) expression causes neonatal respiratory distress syndrome (RDS).

Objectives: To assess developmental and genetic regulation of SP-B expression in vivo.

Methods: To evaluate in vivo developmental regulation of SP-B, we used immunoblotting to compare frequency of detection of mature and pro-SP-B peptides in developmentally distinct cohorts: 24 amniotic fluid samples, unfractionated tracheal aspirates from 101 infants >or=34 weeks' gestation with (75) and without (26) neonatal RDS, and 6 nonsmoking adults.