Mice with surfactant protein (SP)-D deficiency have three to four times more surfactant lipids in air spaces and lung tissue than control mice. We measured multiple aspects of surfactant metabolism and function to identify abnormalities resulting from SP-D deficiency. Relative to saturated phosphatidylcholine (Sat PC), SP-A and SP-C were decreased in the alveolar surfactant and the large-aggreg...

Hydrolysis of surfactant phospholipids by secreted phospholipases A(2) (sPLA(2)) contributes to surfactant dysfunction in acute respiratory distress syndrome. The present study demonstrates that sPLA(2)-IIA, sPLA(2)-V, and sPLA(2)-X efficiently hydrolyze surfactant phospholipids in vitro. In contrast, sPLA(2)-IIC, -IID, -IIE, and -IIF have no effect. Since purified surfactant protein A (SP-A) h...

The acute respiratory distress syndrome (ARDS) is a frequent, life-threatening disease in which a marked increase in alveolar surface tension has been repeatedly observed. It is caused by factors including a lack of surface-active compounds, changes in the phospholipid, fatty acid, neutral lipid, and surfactant apoprotein composition, imbalance of the extracellular surfactant subtype distributi...

Exogenous surfactant treatment inhibits antigen-induced airway obstruction in sensitized guinea-pigs. Aerosolized surfactant also improves respiratory function in asthmatic patients. The aim of the present study was to determine whether aerosolized surfactant inhibits nonallergic airway obstruction induced by acetylcholine. Anaesthetized Wistar rats were treated by aerosol with the beta2-adreno...

The effects of both surfactant distribution patterns and ventilation strategies utilized after surfactant administration were assessed in lung-injured adult rabbits. Animals received 50 mg/kg surfactant via intratracheal instillation in volumes of either 4 or 2 ml/kg. A subset of animals from each treatment group was euthanized for evaluation of the exogenous surfactant distribution. The remain...

Superhydrophobic surfaces (SHSs) have the potential to achieve large drag reduction for internal and external flow applications. However, experiments have shown inconsistent results, with many studies reporting significantly reduced performance. Recently, it has been proposed that surfactants, ubiquitous in flow applications, could be responsible by creating adverse Marangoni stresses. However,...

A model is presented of surfactant replacement therapy. An instilled bolus is pushed into the lungs on the first inspiration, coating the airways with a layer of surfactant and depositing some in the alveoli. Layer thickness depends on the capillary number (muU/gamma, where mu, U, and gamma are bolus viscosity, advancing meniscus velocity, and surface tension, respectively). Larger capillary nu...

Synchrotron x-ray and surface-tension studies of a strong polyelectrolyte (PE) in the semidilute regime (approximately 0.1 M monomer charges) with varying surfactant concentrations show that minute surfactant concentrations induce the formation of a PE-surfactant complex at the gas-solution interface. X-ray reflectivity and grazing angle x-ray diffraction show the complex PE-surfactant resides ...

Current practice guidelines recommend administration of surfactant at or soon after birth in preterm infants with respiratory distress syndrome. However, recent multicenter randomized controlled trials indicate that early use of continuous positive airway pressure with subsequent selective surfactant administration in extremely preterm infants results in lower rates of bronchopulmonary dysplasi...

Current practice guidelines recommend administration of surfactant at or soon after birth in preterm infants with respiratory distress syndrome. However, recent multicenter randomized controlled trials indicate that early use of continuous positive airway pressure with subsequent selective surfactant administration in extremely preterm infants results in lower rates of bronchopulmonary dysplasi...