Spermiogenesis and spermatozoon ultrastructure of the dilepidid cestode Molluscotaenia crassiscolex (von Linstow, 1890), an intestinal parasite of the common shrew Sorex araneus

Spermiogenesis in Molluscotaenia crassiscolex begins with the formation of a differentiation zone containing two centrioles. One of the centrioles develops a flagellum directly into the cytoplasmic extension. The nucleus elongates and later migrates along the spermatid body. During advanced stages of spermiogenesis, a periaxonemal sheath appears in the spermatid. Spermiogenesis finishes with the appearance of a single helicoidal crested body at the base of the spermatid and, finally, the narrowing of the ring of arched membranes causes the detachment of the fully formed spermatozoon. The mature spermatozoon of M. crassiscolex exhibits a partially detached crested body in the anterior region of the spermatozoon, one axoneme, twisted cortical microtubules, a periaxonemal sheath, and a spiralled nucleus. The anterior spermatozoon extremity is characterized by the presence of an electron-dense apical cone and a single spiralled crested body, which is attached to the sperm cell in the anterior and posterior areas of region I, whereas in the middle area it is partially detached from the cell. This crested body is described for the first time in cestodes. The posterior extremity of the male gamete exhibits only the disorganizing axoneme. Results are discussed and compared particularly with the available ultrastructural data on dilepidids sensu lato.

Hospitalisation hors canton : l'exemple du Valais

[Table des matières] 1. Hospitalisation hors canton : Aspects juridiques (Art. 41 Lamal, Art. 124 Loi sur la santé Valais); Aspects statistiques et financiers; Comparaisons intercantonales; Statistiques médicales. 2. Les problèmes, les enjeux : Habitudes régionales; Continuité des soins; Tourisme; Choix du fournisseur de soins; Planification sanitaire; Enseignement de la médecine; Qualité des soins; Bureaucratie. 3. Solutions envisagées : Abandon de l'art. 41 al. 3; Maintien de l'art. 41 al3 aménagé; Négociations tarifaires sur la base des coûts effectifs; Maintien de l'art. 41 al. 3 avec choix pour le patient en cas de monopole; Démarche administrative indépendante des intérêts.