[Ultrastructure of the thymus and neuromuscular junction in myasthenic and non-myasthenic patients].

Ultrastructural changes in 35 neuromuscular junctions taken from myasthenic patients (in 2 cases: hyperplasia of the thymus, in 1 case: epithelial thymoma was present) treated with anticholinesterase during 1--2 years, appeared to be similar to those observed in non-myasthenic patients with lymphoid thymoma (getting no treatment with anticholinesterase). Number of the secretory granules in the epithelial cells of the thymus was in accordance with the severity of the disease. It can be assumed, that in the disturbance of the neuro-muscular transmission of the stimuli the activation of the epithelial cells may play a part.