Browsing by Subject "Mandibular condylar cartilage"

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    Immunohistochemical localization of phosphatidylcholine in rat mandibular condylar surface and lower joint cavity by cryotechniques
    (Murcia : F. Hernández, 2005) Zea-Aragón, Z.; Terada, N.; Ohtsuki, K.; Ohnishi, M.; Ohno, S.
    The immunolocalization of phospholipids has not yet been clearly demonstrated in temporomandibular joints (TMJs). We have examined the distribution of one of phospholipids, phosphatidylcholine (PC), in the rat mandibular condylar surface and lower joint cavity. Some fresh resected TMJs with their disks attached were immediately plunged into isopentane-propane cryogen (-193 °C). Cryostat sections were cut, mounted on NH3 +-coated slides, and fixed with paraformaldehyde (PF). Cryosections were first immunostained with anti-mouse PC antibody (JE-1). Subsequently, they were labeled with immunogold particles following silver enhancing for light microscopic analyses. Some cryosections were subjected to double immunofluoresecence labeling with antifibronectin antibody or hyaluronic acid-binding protein in combination with the anti-PC antibody. As an immunocontrol, other cryosections were pretreated with phospholipase A2 before such immunofluorescence labeling. We have confirmed the presence of PC in the lower joint cavity of rat TMJs as well as on the mandibular condylar surface layer, which was colocalized with hyaluronic acid and fibronectin respectively. However, by treatment with phospholipase A2, such immunolabeling for PC was clearly decreased, showing that the PC is a component in the rat in vivo TMJ. These findings suggest that PC, hyaluronic acid and fibronectin may interact each other in the TMJ articular surface areas to play a functional role for lubrication in TMJ.
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    Ultrastructural study of upper surface layer in rat mandibular condylar cartilage by quick-freezing method
    (Murcia : F. Hernández, 2004) Yoshida, M.; Zea-Aragón, Z.; Ohtsuki, K.; Ohnishi, M.; Ohno, S.
    The purpose of the present study is to clarify native ultrastructures of upper surface layers of the rat mandibular condylar cartilage in vivo by a quickfreezing method. The mandibular cartilaginous tissues were removed with their articular discs attached without opening the lower joint cavity. The specimens were processed for light microscopy, transmission or scanning electron microscopy. Deep-etching replica membranes were also prepared after the routine quick-freezing method. The upper surface layer was well preserved by the quick-freezing method. The cartilaginous tissues, which were fixed without opening their articular discs, appeared to keep better morphology than those after opening them. The upper surface layer was thicker than the corresponding layer as reported before. It consisted of atypical extracellular matrices with lots of apparently amorphous components, which were distributed over typical collagen fibrils, by conventional electron microscopy. As revealed with the replica membranes, it also consisted of variously sized filaments and tiny granular components localized on the typical collagen fibrils. A pair of stereo-replica electron micrographs three-dimensionally showed compact filaments within the upper surface layer. The quick-freezing method was useful for keeping native ultrastructures of the fragile upper surface layer in the mandibular condylar cartilage, which may be functionally important to facilitate smooth movement of the temporomandibular joint.