Biomedical subjects

Y Horisaka

Publications and source records attributed to Y Horisaka.

8 recordsLinked to original sources

PubMed1994

Histological changes of implanted collagen material during bone induction.

Studies were made on the fate of implanted material during bone induction. Mixtures of 1 mg of crude bone morphogenetic protein (BMP), or bovine serum albumin as a control, and 1.5 mg of bovine collagen, were pressed into discs and implanted under the fascia of the rectus abdominus muscle of rats. The tissues with implants were fixed 7, 10, and 14 days later and examined histologically. On day 7 after implantation, the implant was surrounded and invaded by alkaline phosphatase-positive cells. New bone and cartilage were seen at the periphery of the implant. In the regions of calcified cartilage and bone, these osteogenic matrices were intermixed with the implant. The mineral deposits were seen by electron microscopy not only on the osteogenic matrices but also on the implanted collagen. On day 14, the bone had spread to the center of the implant. No osteogenesis or chondrogenesis was seen in control implants. It was concluded that the calcification occurred on the implanted collagen during bone induction, and that it was related to successive bone formation and remodeling.

Alkaline Phosphatase↗

PubMed1993

Purification of water-soluble bone-inductive protein from bovine demineralized bone matrix.

The water-soluble fraction containing bone-inductive activity was purified from guanidine-hydrochloride extracts of bovine demineralized bone. The purification steps include ultrafiltration, dialysis, affinity chromatography on heparin-Sepharose and gel chromatography on Sephacryl S-200. Combination of these steps was proven to be an effective and rapid method for the purification of this protein. Subcutaneous implantation of the water-soluble protein with type I collagen was carried out in the thorax of rats. When alkaline phosphatase activity and calcium content in implants were used as indices for purification, the water-soluble bone-inductive protein was purified > 600-fold according to the enzyme activity and 64-fold according to the calcium content. A morphological examination revealed that many chondrocyte and osteoblast cells were seen in the location of the implanted material. Sodium dodecyl sulfate/gel electrophoresis of the protein produced in this way under non-reducing conditions revealed four protein bands of 18, 16, 14 and 11 kDa. None of the separated bands had any biological activity. This result suggests that the water-soluble bone-inductive activity depends on an associated form of various proteins in the range of 18 to 11 kDa.

Alkaline Phosphatase↗

PubMed1991

Effect of bupivacaine on muscle tissues and new bone formation induced by demineralized bone matrix gelatin.

Heterotopic bone formation induced by demineralized bone matrix gelatin (BMG) in bupivacaine-HCl-treated skeletal muscle was examined histologically. BMG was obtained by dehydrating diaphyseal shafts of femora and tibiae of male, 4-week-old Sprague-Dawley (SD) rats, cutting it into chips, and demineralizing and extracting the chips with various solutions. The BMG was implanted into the rectus abdominis muscle of male, 5-week-old SD rats, bupivacaine-HCl was injected at the same site, and the resulting plaques of tissues were examined histologically on days 5, 10, 15 and 20 after BMG implantation. Heterotopic bone formation occurred in all animals. The bupivacaine-treated group had more degenerated and injured muscle fibers, and more osteocytes than the control group. Electron microscopy showed that the basement membrane of muscle fibers was discontinuous and that many mononucleated cells resembling activated satellite cells were present on day 5. Many fibroblasts, undifferentiated mesenchymal cells and myogenic cells were seen in the area around the BMG. In new bones there were few osteocytes on day 10, but their numbers were increased on days 15 and 20 after implantation, especially in the bupivacaine-treated group. The population of osteocytes that increased rapidly may have included mononucleated cells similar to activated satellite cells.

Abdominal Muscles↗

PubMed1991

The ultrastructure of cartilage formation from neonatal skeletal muscle in vitro.

Histological changes in cultured neonatal skeletal muscle tissue at the early stage of cartilage induction by syngeneic insoluble bone matrix gelatin (BMG) containing bone morphogenetic protein were examined by light and electron microscopy. Minced skeletal muscle was cultured on hemicylindrical pieces of BMG for 14 days. Chondroblasts first appeared in the crevices of the BMG on Day 7 of the culture, and cartilage tissue was seen to fill the crevices completely by Day 10. The main findings in this work are as follows: 1) the activation of satellite cells and necrosis of myonuclei; 2) the migration of satellite cells from the basement membrane; 3) fibroblasts with increased numbers of organelles between degenerated muscle fibers closely resembling the migratory satellite cells; 4) the migration of the spindle-shaped cells into the crevices of the BMG; and 5) change of the spindle-shaped cells to chondroblasts. These findings suggest that neonatal skeletal muscles, which appear more mature than embryonic muscles, also have a chondrogenetic potential when grown on BMG, and that chondroblasts originate from the spindle-shaped cells which are thought to result from migratory satellite cells as well as fibroblasts.

Animals↗

PubMed1991

Architecture of implanted bone matrix gelatin influences heterotopic calcification and new bone formation.

Heterotopic bone formation in skeletal muscle induced by compacted demineralized bone matrix gelatin (BMG) was studied histologically and biochemically. BMG was obtained by dehydrating diaphyseal shafts of femora and tibiae of 4-week-old male Sprague-Dawley rats, cutting the bone into chips, and demineralizing and extracting the chips with various solutions. The BMG was treated with 4 M guanidine-HCl, and compacted BMG was prepared by centrifugation. The compacted BMG was implanted into the rectus abdominis muscle of 5-week-old male Sprague-Dawley rats. The resulting specimens were examined histologically, and their alkaline phosphatase activity and the calcium content of the tissues were measured 3, 5, 7, 10, and 15 days after implantation. The BMG (separated BMG) with 75- to 500-microns particle sizes were implanted into control rats. The results showed that calcification, alkaline phosphatase activity, and bone formation were suppressed by implantation of the compacted BMG and that scarcely any vascularization occurred. Calcification, vascularization, and alkaline phosphatase activity were related and were indispensable for bone formation. In the control group, bone formation was observed at sites of high activity of alkaline phosphatase and well-developed vascularization. These results suggested that compacting of BMG suppressed vascularization, decreased calcification, and consequently reduced the induction of bone formation.

Alkaline Phosphatase↗

PubMed1991

Muscle tissue reactions to implantation of bone matrix gelatin.

Histologic changes of muscle tissue in the early stage of heterotopic osteogenesis induced by syngeneic insoluble bone matrix gelatin (BMG) with bone morphogenetic protein in rats was observed by light and electron microscopy. BMG induced cartilage in muscle tissue by Day 7 after its implantation, woven bone by Day 10, and lamellar bone with bone marrow by Day 14. The new findings in this work include (1) the disappearance of the basement membrane of muscle fibers; (2) the activation of the satellite cells of muscle fibers; (3) the appearance of fibroblastlike cells that closely resembled activated satellite cells among the degenerated muscle fibers or on the surface of the BMG; and (4) the change of fibroblastlike cells to chondroblasts or osteoblasts. These findings suggest that intramuscular implantation of BMG caused the conspicuous disappearance of the basement membrane of the muscle fiber and may play a part in osteogenesis induced by BMG.

Animals↗

PubMed1991

Subperiosteal implantation of bone morphogenetic protein adsorbed to hydroxyapatite.

Bone development was induced by bone morphogenetic protein (BMP) adsorbed to hydroxyapatite (HAP) under the periosteum of rat parietal bone. The BMP was isolated by Sephacryl-S200 column chromatography after passage through a membrane filter system. The yield of the fraction with BMP activity was 20 times greater than yields obtained by conventional methods. BMP was adsorbed to HAP in vacuo. HAP alone was implanted as a control. The formation of cartilage and bone was observed seven days after the implantation of BMP-HAP, and the newly formed bone fused with the host calvaria after 28 days. In control rats, no bone formation was seen within 56 days after implantation. The BMP-HAP complex was more effective in induced periosteal bone formation than HAP only.

Adsorption↗

PubMedDate not supplied

Radiographic analysis of a two-piece apatite implant: Part II. Preliminary report of 2-year observation.

Marginal bone height and bone density were evaluated for 2 years after two-piece dense hydroxyapatite implant (Apaceram) placement using standardized radiography and digital image processing. The chronological changes in marginal bone height were divided into three groups: Group I-level was constant or became higher with time; Group II-bone decreased gradually after superstructure placement; and Group III-bone decreased in height rapidly after abutment placement. Bone density around the successful Apaceram implant, especially in the crestal region, increased clearly. The results suggest that bone resorption/formation around the implant is related to occlusal stress, and that adequate occlusal stress should be exerted on the implant at each phase after the implant placement.

Adult↗