Expressions of extracellular matrix-remodeling factors in lymph nodes from oral cancer patients.

Objective: Most malignant tumors require remodeling extracellular matrices (ECMs) for invasive growth and metastasis. Cancer cells and stromal cells remodel ECM. We investigated the relationship between regional lymph node (LN) metastasis and expression of ECM-remodeling factors in oral squamous cell carcinoma (OSCC).

Regulation and Biological Significance of Formation of Osteoclasts and Foreign Body Giant Cells in an Extraskeletal Implantation Model.

The implantation of biomaterials induces a granulomatous reaction accompanied by foreign body giant cells (FBGCs). The characterization of multinucleated giant cells (MNGCs) around bone substitutes implanted in bone defects is more complicated because of healing with bone admixed with residual bone substitutes and their hybrid, and the appearance of two kinds of MNGCs, osteoclasts and FBGCs. Furthermore, the clinical significance of osteoclasts and FBGCs in the healing of implanted regions remains unclear.

Diversity of multinucleated giant cells by microstructures of hydroxyapatite and plasma components in extraskeletal implantation model.

Unlabelled: Foreign body giant cells (FBGCs) and osteoclasts are multinucleated giant cells (MNGCs), both of which are formed by the fusion of macrophage-derived mononuclear cells. Osteoclasts are distinct from FBGCs due to their bone resorption ability; however, not only morphological, but also functional similarities may exist between these cells. The characterization and diversity of FBGCs that appear in an in vivo foreign body reaction currently remain incomplete.

Effect of silicate incorporation on in vivo responses of α-tricalcium phosphate ceramics.

In addition to calcium phosphate-based ceramics, glass-based materials have been utilized as bone substitutes, and silicate in these materials has been suggested to contribute to their ability to stimulate bone repair. In this study, a silicate-containing α-tricalcium phosphate (α-TCP) ceramic was prepared using a wet chemical process. Porous granules composed of silicate-containing α-TCP, for which the starting composition had a molar ratio of 0.

Promotion of normal healing of bone defects under estrogen deficiency by implantation of beta-tricalcium phosphate composed of rod-shaped particles.

We compared the healing of bone defects in ovariectomized rats implanted with beta-tricalcium phosphate (b-TCP)composed of rod-shaped particles, which were prepared using the applied hydrothermal method (HTCP), and that of bone defects implanted with conventional b-TCP composed of globular-shaped particles (CTCP), which were prepared by normal sintering. Eight week-old female Wistar rats were ovariectomized, and 2 weeks after the operation, 0.5- to 0.

A bone substitute with high affinity for vitamin D-binding protein--relationship with niche of osteoclasts.

The biological activity of osteoblasts and osteoclasts is regulated not only by hormones but also by local growth factors, which are expressed in neighbouring cells or included in bone matrix. Previously, we developed hydroxyapatite (HA) composed of rod-shaped particles using applied hydrothermal methods (HHA), and it revealed mild biodegradability and potent osteoclast homing activity. Here, we compared serum proteins adsorbed to HHA with those adsorbed to conventional HA composed of globular-shaped particles (CHA).

Stimulation of Osteogenesis in Bone Defects Implanted with Biodegradable Hydroxyapatite Composed of Rod-Shaped Particles under Mechanical Unloading.

The aim of this study was to evaluate the influence of mechanical unloading on the repair of bone defects with implantation of biodegradable bone substitutes. Spherical granules of biodegradable hydroxyapatite composed of rod-shaped particles (RHA) or beta-tricalcium phosphate composed of rod-shaped particles (RTCP) were implanted into a bone defect created in the distal end of the right femur of 8-week-old Wistar rats. Two, 6, 10, and 22 weeks after implantation, part of the sciatic nerve in the thigh was resected and exposed to mechanical unloading for 2 weeks.