An Immunohistochemical Study of Matrix Components in Early‐Stage Vascular Canals Within Mandibular Condylar Cartilage in Midterm Human Fetuses

Abstract

Matrix components of vascular canals (VCs) in human fetal mandibular condylar cartilage (15-16 weeks of gestation) were analyzed by immunohistochemistry. Prevascular canals (PVCs), consisting of spindle-shaped cells without capillary invasion, were observed within the cartilage. Intense immunoreactivity for collagen type I, weak immunoreactivity for aggrecan and tenascin-C, weak hyaluronan (HA) staining, and abundant argyrophilic fibers in PVCs indicated that they contain noncartilaginous fibrous connective tissues that was different from those in the perichondrium/periosteum. These structural and immunohistochemical features of PVCs are different from those of previously reported cartilage canals of the long bone. Capillaries entered the VCs from the periosteum and ascended through VCs. Following capillary invasion, loose connective tissue had formed in the lower part of VCs, and immunoreactivity for collagen types I and III, tenascin-C, and HA staining was evident in the matrix of loose connective tissue. No chondroclasts or osteogenic cells were seen at the front of capillary invasion, although small, mononuclear tartrate-resistant acid phosphatase (TRAP)-positive cells were present. Meanwhile, TRAP-positive, multinucleated chondroclasts and flattened, osteoblast-like cells were observed in the loose connective tissue at the lower part of VCs. These results may indicate slow progress of endochondral ossification in human fetal mandibular condyle. Further, unique matrix components in PVCs/VCs, which were different from those in cartilage canals in long bone, may reflect the difference of speed of endochondral ossification in cartilage canals and human fetal mandibular condyles. Anat Rec, 298:1560Rec, 298: -1571Rec, 298: , 2015

The third vascular route of the inner ear or the canal of Cotugno: Its topographical anatomy, fetal development, and contribution to ossification of the otic capsule cartilage

“…As the columns were short but relatively thick, they were called “osseous globules” rather than columns (Sørensen et al, 1992; see the Introduction). The globules were somewhat similar to early vascular canals of the human mandibular condyle at midterm (Shibata et al, 2015). We observed abundant globules, but they were absent at the interface between the CC mesenchymal tissue and the ossified ear.…”

Histochemical and Ultrastructural Study of Developing Gonial Bone With Reference to Initial Ossification of the Malleus and Reduction of Meckel's Cartilage in Mice

“…Formaldehyde-fixed specimens were decalcified in 10% EDTA for 7 days at 4 C, if required, and were routinely embedded in paraffin. Serial sections (6-μm thickness) were cut on the frontal or sagittal plane and stained with 0.1% alcian blue-0.1% acid fuchsin (Shibata et al, 2006a), 0.1% toluidine blue (0.1 M phosphate buffer, pH 7.4), Gomori's silver staining (Drury and Wallington, 1980), or TRAP by the hexasotized pararosaniline method (Lewinson and Silbermann, 1992;Shibata et al, 2003bShibata et al, , 2015. Some specimens were embedded in OCT compound (Sakura FineTek Japan, Tokyo, Japan), and frozen in liquid nitrogen for cryosectioning.…”

An in situ hybridization study of perlecan, DMP1, and MEPE in developing condylar cartilage of the fetal mouse mandible and limb bud cartilage

“…The streptavidin-biotin method with a Histofine SAB kit (Nichirei, Tokyo, Japan) was then performed as previously described. 7 , 31 , 38 , 39 The sections were treated with diaminobenzidine to visualize protein localization. Negative control sections were incubated with normal rabbit or mouse or rat IgG instead of the primary antibodies.…”