SFTPB and acute respiratory distress syndrome: The pulmonary activity of S-MB and MB surfactant (described above) was investigated in comparison to native pig SP-B (positive control) and SP-B(1–8) surfactants and lipids alone (negative control) during a 90 min period following intratracheal instillation of these surfactants into ventilated rats with ARDS induced by in vivo lavage.