Publications by authors named "Norihiro Akiyama"
Material-induced osteoinduction is reported in comparatively large animals such as dogs and pigs; however, it does not often occur in small animals such as rodents. In this study, we implanted porous calcium-deficient hydroxyapatite (CDHA) in the dorsal muscles of dogs and rats and compared the two species, with emphasis on multinucleated cells, by using hematoxylin and eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) staining, transmission electron microscope (TEM) observation, and reverse transcription-polymerase chain reaction (RT-PCR). In CDHA extracted from dogs, numerous TRAP-positive multinucleated cells were detected after 2 weeks and new bone formation was observed after 4 weeks.
View Article and Find Full Text PDFPorous beta-tricalcium phosphate (TCP) has been known to have osteoinductive potential in ectopic site implantation in canine models without the use of osteoinductive substances or cell transplantation. Prostaglandin E2 receptors, particularly EP4, are known to play an important role in osteogenesis. EP4 agonists have been demonstrated to have positive effects on bone remodeling and bone morphogenic protein-induced ectopic bone formation in rodent models.
View Article and Find Full Text PDFObject: Porous biomaterials with adequate pore structure and appropriate mechanical properties are expected to provide a new generation of devices for spinal interbody fusion because of their potential to eliminate bone grafting. The purpose of this study was to evaluate the fusion characteristics of porous bioactive titanium implants using a canine anterior interbody fusion model.
Methods: Porous titanium implants sintered with volatile spacer particles (porosity 50%, average pore size 303 microm, compressive strength 116.