title: The shape modulation of osteoblast-osteocyte transformation and its correlation with the fibrillar organization in secondary osteons: a SEM study employing the graded osmic maceration technique.
abstract: Cortex fractured surface and graded osmic maceration techniques were used to study the secretory activity of osteoblasts, the transformation of osteoblast to osteocytes, and the structural organization of the matrix around the cells with scanning electron microscopy (SEM). A specialized membrane differentiation at the base of the cell was observed with finger-like, flattened processes which formed a diffuse meshwork. These findings suggested that this membrane differentiation below the cells had not only functioned in transporting collagen through the membrane but also in orienting the fibrils once assembled. Thin ramifications arose from the large and flat membrane foldings oriented perpendicular to the plane of the osteoblasts. This meshwork of fine filaments could not be visualized with SEM because they were obscured within the matrix substance. Their 3-D structure, however, should be similar to the canalicular system. The meshwork of large, flattened processes was no more evident in the cells which had completed their transformation into osteocytes.
authors.affiliation: Clinica Ortopedica dell'Università di Brescia, Spedali Civili di Brescia, Brescia, Italy. ortopedia2@spedalicivili.brescia.it
authors.forename: Ugo E
authors.initials: UE
authors.lastname: Pazzaglia
authors.forename: Terenzio
authors.initials: T
authors.lastname: Congiu
authors.forename: Marcella
authors.initials: M
authors.lastname: Marchese
authors.forename: Carlo
authors.initials: C
authors.lastname: Dell'Orbo
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D048430:Cell Shape; D006253:Haversian System / Q000166:cytology* / Q000648:ultrastructure*; D008297:Male; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D009993:Osmium Tetroxide / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology* / Q000648:ultrastructure; D010011:Osteocytes / Q000166:cytology* / Q000648:ultrastructure; D011817:Rabbits
chemical_list: D009993:Osmium Tetroxide