The ultrastructure of Taenia solium oncosphere membrane and egg.

【Objective】 The ultrastructure of oncosphere membrane and egg of Taenia solium were observed in a study. 【Method】 The decoction areca and pumpkin seeds were taken by the patients (limosis) to get T. solium mature eggs. After being treated with sodium hypochlorite to break the eggshells,the oncospheres were gathered with isoosmotic percoll solution and were treated with the artificial intestinal juice to activate oncospheres. Then the ultrastructure of egg and oncosphere membrane were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). 【Result】 The egg was in oval shape with the size of 50-58 μm and consist of embryophore,inner cytoplasmic layer,oncosphere membrane and oncosphere. The structure of developmental T. solium oncosphere membrane was composed of residual layer of outer envelope,outer cytoplasmic layer (including the outer irregular compact layer and the inner homogeneous lucent layer),the embryophore (including blastoderm layer and inner cytoplasmic layer) and oncosphere membrane from outside to inside,respectively. However,there was only one layer in the mature oncosphere membrane with a size of 49-51 nm. 【Conclusion】 The ultrastructure of the oncosphere membrane and egg of T. solium are similar to that of Hymenolepis diminuta and T. saginata except that the envelope is not present around the glycogen granule in underlayer of oncosphere membrane of T. solium.