[Ultrastructural observations on 24 cases of pseudo-hypertrophic muscular dystrophy].

Muscular biopsy specimens of 24 cases of pseudo-hypertrophic (Duchenne's) muscular dystrophy (DMD) were studied with light and electron microscopy. Ultrastructural changes include: I. Disappearance of sarcolemma in focal areas of muscle fibers with degeneration or focal necrosis, which may be the preliminary muscle fiber changes in DMD. 2. Repair of sarcolemma and regenerative sarcomere were observed in some injured muscle fibers, but the ability to repair and regeneration being so weak that injured muscle fibers can not be completely restored. 3. In the early stage of DMD when muscle fibers have not yet to become obviously atrophied, fat cell infiltration between swollen or intact muscle fibers can be observed but cannot be explained. In addition, 3 carriers (mothers of 3 DMD patients) and one asymptomatic brother of a DMD patient were examined, some serological and ultrastructural changes were found.