Ultrastructural observation of neonatal lungs with transmission electron microscope and freeze-fracture replication.

Nine neonatal and one child lungs in various conditions were examined with electron microscopy combined with thin section and freeze-fracture replication techniques in order to study mainly ultrastructural changes of lamellar inclusion bodies of type II alveolar cells. Lungs from neonates with respiratory distress syndrome and with bronchopneumonia showed occasional lamellar inclusions that were partially amorphous in thin section and granular and fragmentarily linear in freeze-fracture preparation. This change was considered to represent focal micelle formation of phospholipid lamellae. No specific morphological changes were noted in lungs of respiratory distress syndrome. In contrast, lungs from thanatophoric dwarfism showed ripple appearance of inclusion lamellae. This was considered to possibly represent unusual phospholipid compounds forming lamellae. Other interesting findings were also described.