Evagination of Taenia solium cysticerci: a histologic and electron microscopy study.
BACKGROUND
After a human being ingests a cysticercus, the larval stage of Taenia solium, the cysticercus gradually develops toward the adult parasite. In this paper, we describe the sequential progress of evagination of cysticerci.


METHODS
Intact cysticerci were obtained from swine muscle, and incubated in bovine bile to stimulate evagination. Dissecting, light, and electron microscopy of whole parasites and histologic sections were used for photographic registers.


RESULTS
The first event was the widening of the opening of the bladder wall for the scolex and neck to emerge. The two chambers that conform the cysticercus were identified. Histologic sections provided explanation for the conformation of the spiral canal. The scolex uncoils during evagination but does not turn inside out.


CONCLUSIONS
The scolex and the neck comprise a different structure from the bladder wall, although they are contiguous.
Rabiela
M T
MT
Departamento de Microbiología y Parasitología, Facultad de Medicina, Mexico City, Mexico.
Hornelas
Y
Y
García-Allan
C
C
Rodríguez-del-Rosal
E
E
Flisser
A
A
D000818:Animals; D001646:Bile; D002417:Cattle; D007814:Larva; D008854:Microscopy, Electron; D013552:Swine; D013621:Taenia / Q000254:growth & development* / Q000648:ultrastructure