Papers by Yoshinori Kuboki
Journal of Japanese Society of Oral Implantology, 1994
Nano Biomedicine, 2010
Pathogenic calcifications involving bacteria Formation of bladder and kidney stones and urinary c... more Pathogenic calcifications involving bacteria Formation of bladder and kidney stones and urinary catheter encrustation. Certain types of bladder and kidney stones are formed due to the action of bacterial urease enzyme. In urinary tract infections these include
The Journal of Biochemistry, 2021
Titanium is the only metal to which osteoblasts can adhere and on which they can grow and form bo... more Titanium is the only metal to which osteoblasts can adhere and on which they can grow and form bone tissue in vivo, resulting in a strong bond between the implant and living bone. This discovery provides the basis for the universal medical application of Ti. However, the biochemical mechanism of bond formation is still unknown. We aimed to elucidate the mechanism of bond formation between collagen, which constitutes the main organic component of bone, and TiO2, of which the entire surface of pure Ti is composed. We analysed the binding between the soluble collagen and TiO2 by chromatography with a column packed with Ti beads of 45 µm, and we explored the association between collagen fibrils and TiO2 (anatase) powders of 0.2 µm. We ran the column of chromatography under various elution conditions. We demonstrated that there is a unique binding affinity between Ti and collagen. This binding capacity was not changed even in the presence of the dissociative solvent 2M urea, but it decre...
Journal of Hard Tissue Biology, 2000
Journal of Hard Tissue Biology, Jun 1, 1999
Bio-medical materials and engineering, 2011
To establish an effective method for bone augmentation, we introduced a new honeycomb-like β-tric... more To establish an effective method for bone augmentation, we introduced a new honeycomb-like β-tricalcium phosphate (H-β-TCP) with BMP-2 as a scaffold, whose unique geometrical properties induce osteoblastic differentiation of autologous bone marrow mesenchymal stem cells (BMSCs). A total of six beagle dogs from 6 to 7 years old were used for this study. BMSCs were cultured with autologous serum and BMP-2 on H-β-TCP. Differentiation to osteoblasts was demonstrated in vitro and exo vivo. Scanning electron microscopy revealed formation and calcification of a matrix-like structure within the H-β-TCP tunnels in BMSC culture. Moreover, treatment of BMP-2 promoted osteoblastic differentiation of BMSCs in H-β-TCP in a diffusion chamber. These results indicated that H-β-TCP may be a useful tool for construction of functional artificial bone.
Nihon rinsho. Japanese journal of clinical medicine, 1998
Bone matrix is composed of collagen and non-collagenous proteins. The collagen is mainly type I c... more Bone matrix is composed of collagen and non-collagenous proteins. The collagen is mainly type I collagen. Characteristics of bone collagen are in posttranslational modifications and utilization of transcriptional elements in the promoter. The non-collagenous proteins are acidic Ca-binding proteins: bone Gla protein(BGP), bone sialoprotein (BSP), osteopontin, osteonectin etc. BGP and BSP are specific to bone, and other proteins are present also in non-mineralized tissues. BGP functions in suppression of excessive mineralization. BSP and osteopontin are sialoproteins containing a RGD cell-attachment sequence and poly(acidic amino acid) sequences. BSP is present in sites of bone formation. Osteopontin is involved in attachment of osteoclasts to bone surface.
Plastic and Reconstructive Surgery, 2001
Journal of Biomedical Materials Research, 2002
On the basis of currently available knowledge, we hypothesize that the initial bone formation, as... more On the basis of currently available knowledge, we hypothesize that the initial bone formation, as induced by bone morphogenetic protein (BMP), is influenced by the chemical composition and three-dimensional spatial configuration of the used carrier material. Therefore, in the current study, the osteoinductive properties of porous titanium (Ti) fiber mesh with a calcium phosphate (Ca-P) coating (Ti-CaP), insoluble bone matrix (IBM), fibrous glass membrane (FGM), and porous particles of hydroxy apatite (PPHAP) loaded with rhBMP-2 were compared in a rat ectopic assay model at short implantation periods. Twelve Ti-CaP, 12 IBM, 12 FGM, and 12 PPHAP implants, loaded with rhBMP-2, were subcutaneously placed in 16 Wistar King rats. The rats were sacrificed at 3, 5, 7, and 9 days post-operative, and the implants were retrieved. Histological analysis demonstrated that IBM and Ti-CaP had induced ectopic cartilage and bone formation by 5 and 7 days, respectively. However, in PPHAP, bone formation and cartilage formation were seen together at 7 days. At 9 days, in Ti-CaP, IBM, and PPHAP, cartilage was seen together with trabecular bone. At 9 days, in FGM, only cartilage was observed. Quantitative rating of the tissue response, using a scoring system, demonstrated that the observed differences were statistically significant (Wilcoxon rank sum test, p < 0.05). We conclude that IBM, CaP-coated Ti mesh, FGM, and PPHAP provided with rhBMP-2 can indeed induce ectopic bone formation with a cartilaginous phase in a rat model at short implantation periods. Considering the different chemical composition and three-dimensional spatial configuration of the carrier materials used, these findings even suggest that endochondral ossification is present in rhBMP-2-induced osteogenesis, even though the amount of cartilage may differ.
Developmental Biology, 1995
Connective Tissue Research, 1988
Dentin phosphophoryn was quantified on bovine and rabbit dentin at three developmental stages. Ph... more Dentin phosphophoryn was quantified on bovine and rabbit dentin at three developmental stages. Phosphophoryn was extracted from teeth with 0.6M HCl, and quantified as optical density on DEAE-cellulose chromatogram or as phosphoserine content. Bovine phosphophoryn showed progressive increase with formation of dentin. Matrix-associated phosphophoryn was also quantified as phosphoserine content in insoluble dentin residue which was extracted with 6 M urea after decalcification. This fraction increased with formation of dentin both in bovine and rabbit dentin. Phosphophoryn is thought to be related to the later stage of dentin formation.
Connective Tissue Research, 1997
A correlation among the oriented growth of octacalcium phosphate (OCP), the arrangement of the co... more A correlation among the oriented growth of octacalcium phosphate (OCP), the arrangement of the collagen fibrils in a collagenous matrix and direction of ionic flow was studied in vitro at pH7.0 and at 37 degrees, using two types of collagen disks made from sliced bovine Achilles tendon. Disk A and disk B were made from slices cut perpendicular and parallel to the collagen fibrils, respectively. The products on the collagen fibrils were a mixture of OCP and apatite in the both disks, but the relative amounts of apatite and OCP could not be determined. Short plate-like or flake-like OCP crystals grew parallel to the collagen fibrils and ionic flow on the Ca-side of the disk A. On the contrary, ribbon-like or rectangular OCP crystals grew along the collagen fibrils lying on the disk B. Apatite also grew with the same orientation as OCP in the both cases. The oriented and length-wise growth of OCP crystals on the disk B was ascribed to the arrangement of the collagen fibrils in the disk.
Connective Tissue Research, 1981
A peptide containing 59 amino acid residues with a stoichiometric amount of dihydroxylysinonorleu... more A peptide containing 59 amino acid residues with a stoichiometric amount of dihydroxylysinonorleucine (0.7 mole) and hydroxylysinonorleucine (0.2 mole) was isolated from reduced 3H labelled bovine bone collagen sequentially cleaved with CNBr and trypsin. Further cleavage of the isolated crosslinked peptide with periodate yielded a radioactive peptide of 45 residues and a non-radioactive peptide of 16 residues. From the characteristic amino acid composition of these peptides it was deduced that the peptide was derived from an intermolecularly crosslinked region between lysyl or hydroxylysl residues in the carboxy-terminal extension of alpha 1-CB6 (17C residue) and alpha 1-CB5 (87th residue). This finding supports the observation that the alpha 1-CB6 peak was prominent on carboxymethyl cellulose chromatography of the CNBr digest of bone collagen only after limited pepsin digestion, and is consistent with the results obtained from a smaller crosslinked peptide previously isolated from calf bone collagen.
Calcified Tissue International, 1982
Anatomy and Embryology, 1997
Chondroid bone is a unique calcified tissue intermediate between bone and cartilage. To clarify i... more Chondroid bone is a unique calcified tissue intermediate between bone and cartilage. To clarify its characteristics, we examined the distributions of the ECMs associated with chondrogenic differentiation and matrix calcification in the chondroid bone of the rat glenoid fossa, and compared them to those in two typical bone tissues, alveolar bone of the maxilla (intramembranous bone) and the growth plate of long bone (endochrondral bone), using immunofluorescence techniques. Morphologically, the glenoid fossa consisted of the fibrous, progenitor and cartilaginous cell layers and the cartilaginous cell layer was further divided into the superficial non-hypertrophic layers (secondary cartilage) and the deep hypertrophic cell layers (chondroid bone). The co-distribution of type I and type II collagens was observed in secondary cartilage and chondroid bone, whereas type X collagen was restricted to the pericellular matrix of hypertrophied cells (chondroid bone). Osteocalcin, which was absent from the calcified cartilage of endochondral bone formation, was also present in the ECM of the chondroid bone, but not in cells. These results demonstrate that chondroid bone of rats, which is adjacent to secondary-type cartilage in the glenoid fossa, has phenotypic expressions associated with both hypertrophied chondrocytes and osteocytes.
Biological & Pharmaceutical Bulletin, 1996
Biochemical and Biophysical Research Communications, 1981
... 1, 1981 BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS ... Characterization of the reduc... more ... 1, 1981 BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS ... Characterization of the reducible crosslink pattern in dentin collagen showed that the most abundant crosslink in this collagen was dihydroxylysinonorleucine (DHLNL) (13), but quantitation of ...
Biochemical and Biophysical Research Communications, 1991
We examined the effect of histatin 5 from human parotid saliva on various proteases. Histatin 5 s... more We examined the effect of histatin 5 from human parotid saliva on various proteases. Histatin 5 strongly inhibited a trypsin-like protease produced by Bacteroides gingivalis with an IC50 value of 55 nM. Clostripain was also inhibited (IC50 = 800 nM). Activities of other proteases were not affected significantly. Because B. gingivalis is a suspected periodontal pathogen and its proteolytic enzymes have been considered to be associated with periodontal tissue destruction, it is suggested that salivary histatins play a role as a preventive against periodontal disease.
Artificial Organs, 2013
Titanium net (meshes) with excellent mechanical properties can promote bone compatibility and has... more Titanium net (meshes) with excellent mechanical properties can promote bone compatibility and has been used as a repairing material for bone defects in clinical settings. In the present study, using spiral computed tomography (CT) and histomorphological techniques, we investigated the effect of a novel kind of titanium web with a three-dimensional (3D) porous structure on bone formation in rabbit skull (os parietal) defect. The images from the spiral CT scan demonstrate that the titanium web is completely fused with the surrounding bone tissue, even at the first month after implantation. The histomorphological findings show that different cells and tissues, including osseous tissue, connective tissue, and adipose cells, can easily grow into the 3D scaffold meshes of the titanium web, even in the center of the web and combine together as a whole body, suggesting that the titanium web possesses a very good biocompatibility, which is beneficial to the growth of bone tissue and promotes healing of the defected rabbit skull.
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Papers by Yoshinori Kuboki