• The Korean Journal of Pain
• /
• v.30 no.2
• /
• pp.86-92
• /
• 2017

Osteoblasts, originating from mesenchymal cells, make the receptor activator of the nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in order to control differentiation of activated osteoclasts, originating from hematopoietic stem cells. When the RANKL binds to the RANK of the pre-osteoclasts or mature osteoclasts, bone resorption increases. On the contrary, when OPG binds to the RANK, bone resorption decreases. Denosumab (AMG 162), like OPG (a decoy receptor), binds to the RANKL, and reduces binding between the RANK and the RANKL resulting in inhibition of osteoclastogenesis and reduction of bone resorption. Bisphosphonates (BPs), which bind to the bone mineral and occupy the site of resorption performed by activated osteoclasts, are still the drugs of choice to prevent and treat osteoporosis. The merits of denosumab are reversibility targeting the RANKL, lack of adverse gastrointestinal events, improved adherence due to convenient biannual subcutaneous administration, and potential use with impaired renal function. The known adverse reactions are musculoskeletal pain, increased infections with adverse dermatologic reactions, osteonecrosis of the jaw, hypersensitivity reaction, and hypocalcemia. Treatment with 60 mg of denosumab reduces the bone resorption marker, serum type 1 C-telopeptide, by 3 days, with maximum reduction occurring by 1 month. The mean time to maximum denosumab concentration is 10 days with a mean half-life of 25.4 days. In conclusion, the convenient biannual subcutaneous administration of 60 mg of denosumab can be considered as a first-line treatment for osteoporosis in cases of low compliance with BPs due to gastrointestinal trouble and impaired renal function.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.27 no.2
• /
• pp.123-130
• /
• 2005

Many of the molecular and genotypic events taking place at the osteoblast cell level during bone-implant integration are still largely unknown. The objective of this study was to examine expression patterns of TGF-$\beta$ and IGF-I related genes during bone-implant integration. Titanium implants with machined surface were placed into 8 rabbit tibias. At 3rd, 7th, 14th, 28th day after implantation, the expression pattern of TGF-$\beta$ and IGF-I genes in bone with or without implant was examined using reverse transcriptase-polymerase chain reaction (RT-PCR). At the same time, histomorphometric analysis was evaluated, respectively. The bone-to-implant contacts (BIC) of experimental groups were 5.2%, 6.2%, 6.6%, 24.6% at 3rd, 7th, 14th, 28th day. This indicated that newly formed bone increased at the implant surface in bone marrow space after implantation. The expressions of TGF-$\beta$ and IGF-I were higher in implantation groups than untreated control groups during all experimental days. The increased expression of TGF-$\beta$ and IGF-I genes may be associated with the increased bone-to-implant contact. This result provided the evidence for existing biologic differences in tissue response after implantation and helped us to understand molecular biologic processes in tissue-implant integration.

• Journal of Korean Medicine Rehabilitation
• /
• v.29 no.2
• /
• pp.135-147
• /
• 2019

Objectives This study was performed to evaluate the effect of Pyrola japonica extract (NJ) and its principal constituent, homoarbutin (HA) on osteoclast differentiation and gene expression and bone resorption. The osteoclastogenesis and gene expression were determined in receptor activator of nuclear factor kappa B ligand (RANKL)-stimulated RAW264.7 cell. Methods In order to evaluate the effect of HA extracted from NJ on bone resorption, osteoclasts were used to be differentiated and formed by stimulating RAW264.7 cells with RANKL. Tartarate-resistant acid phosphatase (TRAP) (+) polynuclear osteoclast formation ability was evaluated, and differentiation control genes including cathepsin K, matrix metalloproteinases-9 (MMP-9), and TRAP in osteoclast differentiation were analyzed by real-time polymerase chain reaction (PCR). Immunoblotting was performed to measure the effect of mitogen-activated protein kinase (MAPK) factors on bone resorption, and the effect of osteoclasts on osteoclast differentiation was measured. Results Both NJ and high concentration of HA blocked RANKL-stimulated differentiation from RAW264.7 cell to TRAP-positive multinucleated cells. NJ reduced RANKL-induced expression of TRAP, cathepsin K. Both NJ and high concentration of HA inhibited RANKL-mediated expression of MMP-9, nuclear factor of activated T-cells, cytoplasmic 1, and cellular Jun-fos. NJ suppressed RANKL-stimulated expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase, tumor necrosis factor-alpha, and levels of interleukins. Both NJ and HA decreased bone resorption in osteoclast-induced bone pit formation model. Conclusions These results suggest that NJ and HA blocked bone resorption by decreasing RANKL-mediated osteoclastogenesis through down-regulation of genes for osteoclast differentiation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.47 no.6
• /
• pp.454-464
• /
• 2021

Objectives: This study aimed to investigate the in vitro osteoinductivity of the combination of bone morphogenetic protein-2 (BMP-2) and nanohydroxyapatite (nHAp) and the in vivo effects of implants coated with nHAp/BMP-2. Materials and Methods: To evaluate the in vitro efficacy of nHAp/BMP-2 on bone formation, bone marrow-derived mesenchymal stem cells (BM-MSCs) were seeded onto titanium disks coated with collagen (Col), Col/nHAp, or Col/nHAp/BMP-2. Protein levels were determined by a biochemical assay and reverse transcriptase-polymerase chain reaction. Stem cell differentiation was analyzed by flow cytometry. For in vivo studies with mice, Col, Col/nHAp, and Col/nHAp/BMP-2 were injected in subcutaneous pockets. Titanium implants or implants coated with Col/nHAp/BMP-2 were placed bilaterally on rabbit tibias and evaluated for 4 weeks. Results: In the in vitro study, BM-MSCs on Col/nHAp/BMP-2 showed reduced levels of CD73, CD90, and CD105 and increased levels of glycosaminoglycan, osteopontin, and alkaline phosphatase activity. After 4 weeks, the Col/nHAp/BMP-2 implant showed greater bone formation than the control (P=0.07), while no differences were observed in bone implant contact and removal torque. Conclusion: These results suggest that a combination of BMP-2 and an nHAp carrier would activate osseointegration on dental implant surfaces.

• The Korea Journal of Herbology
• /
• v.37 no.1
• /
• pp.51-59
• /
• 2022

Objectives : The process through which mesenchymal cells condense and differentiate into chondrocytes to form new bone is known as endochondral bone formation. Chondrogenic differentiation and hypertrophy are essential steps in bone formation and are influenced by various factors. The stem bark and root bark of Eleutherococcus sessiliflorus (ES) have been widely used to treat growth retardation and arthritis in traditional Korean Medicine. In this study, we aimed to investigate the possible role of the stem bark of ES in the stimulation of chondrogenic differentiation in clonal murine chondrogenic ATDC5 cells. Methods : In ATDC5 cells treated with ES extract, cell viability and extracellular matrix production were determined using CCK-8 assay and Alcian blue staining, respectively, and alkaline phosphatase activity was measured. We also examined mRNA and protein expression levels of genes related to chondrogenic expression in ATDC5 cells using reverse transcription-polymerase chain reaction and western blot analyses. Results : ES extract increased the accumulation of Alcian blue-stained cartilage nodules and alkaline phosphatase activity in ATDC5 cells. It increased the mRNA expressions of chondrogenic markers including bone sialoprotein (BSP), cartilage collagens, Runt-related transcription factor-2 (RUNX-2), osteocalcin (OCN), β-catenin, and bone morphogenetic protein-2 (BMP-2), as well as the protein expressions of β-catenin, RUNX-2, BMP-2, and alkaline phosphatase (ALP). Conclusion : Taken together, these results suggest that ES extract exhibits a chondromodulating activity and therefore may be a possible agent for the treatment of bone growth disorders.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.6
• /
• pp.777-780
• /
• 2001

Cholesterol granuloma of frontal bone is a rare disease which usually occurs at the lateral part of the supraorbital ridge. This expanding lesion grows slowly and extends into the orbit and anterior cranial fossa. The most common symptom is proptosis. This granuloma is composed of a granulomatous reaction surrounding cholesterol crystals. Surgical treatment involves aspiration of contents and stripping or curettage of the lining which is highly successful. We experienced a case of cholesterol granuloma of frontal bone with huge intracranial extension, which was cured by surgical removal. The clinical features, radiologic, and pathologic finding were discussed and the pertinent literatures were reviewed.

• YAKHAK HOEJI
• /
• v.50 no.1
• /
• pp.26-32
• /
• 2006

Osteocalcin is a vitamin K dependent and bone specific protein which plays an important role in the regulation of bone and calcium metabolism. In this study, we evaluated the relationship between the C298T polymorphism in the osteocalcin gene and bone mineral density (BMD) in Korean young men and their interaction with physical activity. BMDs of the femoral neck and lumbar spine were measured using dual energy X-ray absorptiometry, and the C298T polymorphism in the osteocalcin gene determined using polymerase chain reaction (PCR)-HindIII restriction fragment length polymorphism (RFLP) method. We did not observe any significant differences in the femoral neck and lumbar spine BMDs across genotypes of this polymorphism in controls, athletes or combined groups, respectively (P>0.05). Therefore, our data suggest that the C298T polymorphism in the osteocalcin gene is not a suitable genetic marker for the susceptibility to BMD.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.8 no.1
• /
• pp.55-63
• /
• 1981

The purpose of this study is to observe the effect of formocresol and glutaraldehyde to tooth germs and periapical tissues after perforation of interradicular portion of pulpal floor and application of physiological saline solution in control groups, formocresol and glutaraldehyde in experimental groups. The following results were obtained 1. In control groups, normal healing processes were seen, and, on the sixteenth day, the epithelization of injured areas was completed. Inflammatory reactions were limited to the injured surface, and the underlying alveolar bone were normal and successive tooth germs were normal. 2. In both formocresol groups and glutaraldehyde groups, tissue reactions were identical. Inflammatory reactions were slightly compared with control groups, but the surface epithelizations were delayed compared with control group. 3. In both formocresol and glutaraldehyde groups, necrosis was seen in superficial tissue of bone marrow, and, at 24th day, center area of bone marrow on the successive tooth germs were losed and replaced with connective tissue, and superficial soft tissue of the injured area was connected with soft tissue on the successive tooth germ. In remaining alveolar bone, osteoclastic reaction was remarkable. 4. In both formocresol and glutaraldehyde groups, there is no injury to the successive tooth germs. 5. In both formocresol and glutaraldehyde groups, periodontal membrane was normal, but the partial resorption of cementum and dentin near the injured area were seen.

• The Journal of the Korean bone and joint tumor society
• /
• v.5 no.1
• /
• pp.51-55
• /
• 1999

Aspirin has usually been taken for pain relief originating in the nidus of osteoid osteoma, however it takes too long to become effective. Because of the protracted painful course and the unpredictability of regression, osteoid osteoma is usually removed. And then, the defective host bone is internally fixed by plate and screws and augumented by autogenous bone graft. However, the common intracortical location and exuberant periosteal reaction hinders the exact intraoperative localization of the nidus. The authors managed 6 patients by computerized tomography-guided percutaneous nidus excision with a relatively small skin incision, small cortical window, short operation time and no bone graft. It may be one of the best options for removal of the nidus of osteoid osteoma with certainty.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.28 no.4
• /
• pp.256-263
• /
• 2002

Using the rat's skull, the study on the biodegradability and guided bone regeneration of the chitosan membrane was performed. The results are as follows: 1. The biodegradability of the chitosan membrane could not be confirmed, but after 12 weeks, this membrane did not yet break into small pieces and there was no specific local tissue reaction. 2. It was not certain whether the pore size of this membrane was affected on osteoblastic activity. 3. After 6 weeks, the bony defect area of rat's skull was not completely filled, but on high magnification it showed that the osteoclasts and the osteoblasts were observed in the regenerating area. In conclusion, the chitosan membrane developed in this study was fit for guided bone regeneration.