• International Journal of Oral Biology
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• v.45 no.4
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• pp.162-168
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• 2020

Calcium is the most abundant stored mineral in the human body and is especially vital for bone health; thus, calcium deficiency can cause bone-related diseases, such as osteopenia and osteoporosis. However, a high concentration of serum calcium, which is commonly known as hypercalcemia, can also lead to weakened bones and, in severe cases, osteosarcoma. Therefore, it is necessary to maintain the concentration of calcium that is appropriate for bone biology. In the present study, we aimed to elucidate the effects of high concentration of calcium, approximately 2 folds the normal calcium level, on osteoblast differentiation. The CaCl2 treatment showed dose-dependent suppression of the alkaline phosphatase activity and mineralized nodule formation. Calcium showed cytotoxicity at an extremely high concentration, but a moderately high concentration of calcium that results in inhibitory effects to osteoblast differentiation showed no signs of cytotoxicity. We also confirmed that the CaCl2 treatment repressed the mRNA expression and protein abundance of various osteogenic genes and transcriptional factors. Considered together, these results indicate that a high concentration of calcium negatively regulates the osteoblast differentiation of C2C12 cells.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.102-108
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• 2005

The incidence of anterior cruciate ligament tears is increasing as a result of the increasing participation of individuals of all ages in high-risk sports. Endoscopic anterior cruciate ligament reconstruction using autogenous central third bone-patellar tendon-bone graft is the most commonly used method. With regard to BPTB graft as the go]d standard in ACL reconstruction, there are no data that refute this claim to date. Author reviewed the biomechanical properties, donor site morbidity and selection of the bone-patellar tendon-bone graft and described the surgical technique of endoscopic ACL reconstruction using BPTB autograft.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.255-260
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• 2010

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.

• Archives of Reconstructive Microsurgery
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• v.9 no.1
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• pp.80-87
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• 2000

Acute high speed accidents that results in full thickness skin defect and exposure of tendon, nerve, vessel and periosteum over denuded bone demands soft tissue coverage. Exposed bone often ensues chronic infection and requires free flap transplantation which surely covers defects in one stage operation and enhances transport of oxygen-rich blood and converts a non-osteogenic or partially osteogenic site into a highly osteogenic site, but exposed bone which had performed free flap transplantation sometimes necroses and needs secondary bone procedure. Scar contracture limits joint motion should be excised and covered with normal soft tissue to restore normal range of motion. Authors have performed the large latissimus dorsi myocutaneous free flap in 8 cases of extensive soft tissue defect and exposed bone lesion in the leg and 1 case of the flap was failed. The secondary ilizarov bone procedure was performed in 3 of 8 cases. 2 cases of large burn scar contracture and 1 case of posttraumatic scar contracture in lower extremity were restored with the large latissimus dorsi myocutaneous free flap. Authors concluded that large latissimus dorsi myocutaneous free flap is the most acceptable microvascular procedure in large soft tissue defect combined with exposed periosteum and bone requiring secondary bone procedure and in large burn scar contracture limiting knee joint motion.

• Journal of radiological science and technology
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• v.44 no.1
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• pp.25-30
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• 2021

The purpose was to reduce the distortion of the image that occurs in the temporal bone area due to the very strong differences in susceptibility. A new SS-TSE technique was applied when examining the diffusion-weighted image of the temporal bone, where the auditory and facial nerves to be imaged were very thin and were adjacent to the cranial base including bone and air. This study was conducted from March 2020 to August of the same year, targeting 32 subjects who underwent the diffusion-weighted imaging of the temporal bone. To compare the distortion, existing SS-EPI technique and the new SS-TSE technique were both applied on the temporal bone area. As a result of the study, applying the new SS-TSE technique appeared to lower the distortion of images by 87.44, 46.13 and 42.35 % on the b-value 0, 800 and the ADC images, respectively. In conclusion, when using the new SS-TSE technique on the temporal bone DWI, distortion can be reduced, and thus images with high diagnostic value can be obtained.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.396-401
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• 2013

Chronic osteomyelitis is an infection and inflammation of the bone or bone marrow, causing ischemia in bone marrow due to lack of blood, nutrients, and oxygen supply to the bone marrow, eventually leading to necrosis of bone marrow. A current method for treatment of chronic osteomyelitis is administration of systemic antibiotics followed by removal of the infected bone and tissues. Because infected tissue of chronic osteomyelitis is surrounded by avascular necrotic bone, supply of blood and antibiotics to the infected area is diminished. For effective treatment, high plasma concentrations of antibiotics should be provided for a prolonged period. However, long term high serum level of antibiotics may result in undesirable adverse effects. For delivery of a sufficient concentration of antibiotic to the infected area while avoiding the adverse effect, implantation of a local antibiotic delivery system is suggested. One of the implantation systems that has been utilized is antibiotic impregnated polymethyl methacrylate.

• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.189-196
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• 2006

Micro computed tomography (micro-CT) has been used for in vivo animal study owing to its noninvasive and high spatial resolution capability. However, the sizes of existing detectors for micro-CT systems are too small to obtain whole-body images of a small animal object with $\sim$10 micron resolution and a part of its bones or other organs should be extracted. So, we have introduced the zoom-in micro-tomography technique which can obtain high-resolution images of a local region of an live animal object without extracting samples. In order to verify our zoom-in technique, we performed in vivo animal bone study. We prepared some SD (Sprague-Dawley) rats for making osteoporosis models. They were divided into control and ovariectomized groups. Again, the ovariectomized group is divided into two groups fed with normal food and with calcium-free food. And we took 3D tomographic images of their femurs with 20 micron resolution using our zoom-in tomography technique and observed the bone changes for 12 weeks. We selected ROI (region of interest) of a femur image and applied 2D FDT (fuzzy distance transform) to measure the trabecular bone thickness. The measured results showed obvious bone changes and big differences between control and ovariectomized groups. However, we found that the reliability of the measurement depended on the selection of ROI in a bone image for thickness calculation. So, we extended the method to 3D FDT technique. We selected 3D VOI (volume of interest) in the obtained 3D tomographic images and applied 3D FDT algorithm. The results showed that the 3D technique could give more accurate and reliable measurement.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.2
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• pp.135-147
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• 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 Technologic Dentistry
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• v.42 no.4
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• pp.348-354
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• 2020

Purpose: Zirconia is differentiated from other ceramics because of its high resistance to corrosion and wear, excellent flexural strength (900~1400 MPa), and high hardness. Dental zirconia with proven mechanical/biological stability is suitable for the manufacture of implants. However, there are limited in vivo studies evaluating stress distribution in zirconia compared with that in titanium implants and studies analyzing finite elements. This study was conducted to evaluate the stress distribution of the supporting bone surrounding zirconia and titanium implants using the finite element analysis method. Methods: For finite element analysis, a single implant-supported restoration was designed. Using a universal analysis program, eight occlusal points were set in the direction of the occlusal long axis. The occlusal load was simulated at 700 N. Results: The zirconia implant (47.7 MPa) von Mises stress decreased by 5.3% in the upper cortical bone compared with the titanium implant (50.2 MPa) von Mises stress. Similarly, the zirconia implant (20.8 MPa) von Mises stress decreased by almost 4% in the cancellous bone compared with the titanium implant (21.7 MPa) von Mises stress. The principal stress in the cortical and cancellous bone exhibited a similar propensity to von Mises stress. Conclusion: In the supporting bone, the zirconia implant is able to reduce bone resorption caused by mechanically transferred stress. It is believed that the zirconia implant can be a potential substitute for the titanium implant by reinforcing aesthetic characteristics and improving stress distribution.

• Korean Journal of Adult Nursing
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• v.27 no.4
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• pp.459-471
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• 2015

Purpose: The purpose of this study was to develop a smartphone application and evaluate it's effectiveness and usability for promoting bone health in Korean young adult women. Methods: A smartphone application was developed covering exercise, nutrition, and health habits related to bone health. A pilot testing was conducted using a one-group pre/posttest design. A total of 22 female college students with low bone mass participated in the 8-week use of a pilot testing. Results: The "Strong bone Fit body (SbFb)" application was developed using Android platform. In the pilot testing, bone mineral density, serum CTX, and 25 (OH)Vit.D were significantly decreased. There is no significant change in serum osteocalcin and calcium. Serum phosphorus concentration, nutrient intakes (fiber, VitB6, and pantotenic acid), and all bone composition profiles were significantly increased. Bone-health knowledge was significantly increased but no change in health belief and self-efficacy. Conclusion: The results of this pilot testing suggest the effectiveness of the SbFb application to enhance and promote self-managing abilities for bone health. It can provide continuous feedback and high-quality bone health information. However, some contents and working methods of the application need to be modified and its effectiveness on bone health requires further investigations.