• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.357-364
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• 2007

This experiment was designed to clarify the effect of extracellular glucose on the osteoblasts and periodontal ligament cells. The cells were incubated for 24 and 48 hours with ${\alpha}$-MEM including 1,000 mg/L (control group) and 4,500 mg/L (experimental group) of glucose. Then, the expressions of caspase-3, p38 MAPK, JNK-1, and ERK-1 were examined using Elisa assay and Western blot. The results were as follows: 1. The expression of caspase-3 and p38 MAPK was increased by the high extracellular glucose in both cells. 2. The expression of caspase-3 and p38 MAPK was increased greatly in the periodontal ligament cells than the E1 cells by the high extracellular glucose. 3. The expression of JNK-1 was increased by the high extracellular glucose in both cells. 4. The expression of ERK-1 was not changed by the high extracellular glucose in both cells. These results suggest that extracellular glucose at high concentrations may inhibit the periodontal regeneration process increasing cellular apoptosis. And p38 MAPK and JNK-1 pathway may be the most responsible intracellular pathway rather than ERK-1.

• Biomaterials and Biomechanics in Bioengineering
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• v.1 no.2
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• pp.63-71
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• 2014

This study aimed to develop a novel bioactive hybrid xerogel consisting of silk fibroin /$SiO_2-CaO-P_2O_5$ by sol-gel process at room temperature. Scanning electron microscopy (SEM), FT-IR Spectroscopy, pore measurement, mechanical property testing, in vitro bioactivity test and cytotoxicity assay were performed to characterize the xerogel for bone tissue engineering application. We have found that the xerogel possessed excellent pore structures and mechanical property. Once immersed in a simulated fluid (SBF), the xerogel exhibited profound bioactivity by inducing hydroxyapatite layers on its surfaces. The cell toxicity study also demonstrated that there was little toxic to MC3T3-E1 cells. These results indicate that silk fibroin /$SiO_2-CaO-P_2O_5$ hybrid xerogel potentially could be used as a bone tissue engineering material.

• Korean Journal of Poultry Science
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• v.32 no.4
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• pp.291-300
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• 2005

Two experiments were carried out to assess the appropriate incubation conditions namely; duration, moisture content and the ideal microbial inoculant for fermented dried food waste(EW) offered to broilers. The nutrient utilization of birds fed the FW diets at varying dietary inclusion rates was also compared with a control diet. In Experiment 1, different moisture contents(MC) of 30, 40, 50 and $60\%$ respectively were predetermined to establish the ideal duration of incubation and the microbial inoculant. A 1mL Aspergillus oryzae(AO) $(1.33\times10^5\;CFU/mL)$ was used as the seed inoculant in FW. This results indicated that the ideal MC for incubation was $40\~50\%$ while the normal incubation time was > 72 hours. Consequently, AO seeds at 0.25, 0.50, 0.75 and 1.00mL were inoculated in FW to determine its effect on AO count. The comparative AO count of FW incubated for 12 and 96 hours, respectively showed no significant differences among varying inoculant dosage rates. The FW inoculated with lower AO seeds at 0.10, 0.05 and 0.01mL were likewise incubated for 72 and 96 hours, respectively and no changes in AO count was detected(p<0.05). The above findings indicated that the incubation requirements for FW should be $%40\~50\%$ for 72 hours with an AO seed incoulant dosage rate of 0.10mL. Consequently, in Experiment II, after determining the appropriate processing condition for the FW, 20 five-week old male Hubbard strain were used in a digestibility experiment. The birds were divided into 4 groups with 5 pens(1 bird per pen). The dietary treatments were; Treatment 1 : Control(Basal diet), Treatment 2 : $60\%$ Basal+4$40\%$ FW, Treatment 3 : $60\%$ $Basal+20\%\;FW+20\%$ AFW(Aspergillus oryzae inoculate dried food-waste diet) and Treatment 4: $60\%$ Basal+$40\%$ Am. Digestibility of treatment 2 was lowed on common nutrients and amino acids compared with control(p<0.05) and on crude fat and phosphorus compared with AFW treatments(T3, T4)(plt;0.05). Digestibility of treatment 3 and 4 increased on crude fiber and crude ash compared treatment 2 (p<0.05). Digestibility of control was high on agrinine, leucine, and phenylalnine of essential amino acids compared with treatment 3 and 4(p<0.05), and diestibility of treatment 3 and 4 was improved on arginine, lysine, and threonine of essential amino acids. Finally, despite comparable nutrient utilization among treatments, birds fed the dietary treatment containing AO tended to superior nutrient digestion to those fed the $60\%$ Basa1+$40\%$ FW.

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.277-289
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• 1999

The ultimate aim of periodontal treatment is periodontal regeneration, which necessiates the regeneration of bone tissues. To evaluate the effects of Dex growth and differentiation of MC3T3-E1 cells, cells were seeded in alpha-modified eagle medium containing 10% fetal bovine serum, 10mM beta-glycerophosphate , $50{\mu}g/ml$ of ascorbic acid, with or without $10^{-7}M$ Dex and examined cell proliferation activities, alkaline phosphatase activities, and bone nodule formation until 25days. The results were as follows : 1. In Dex group, cell proliferation activities were lower until 15 days compared to control group. Bone nodules formation were showed at 10 days. 2. In the time-response effect, ALP activities were increased until the 10 days in control groups thereafter decreased and ALP activities of Dex group were lower aspect than control group until the 10 days In this study, bone nodule formation of osteoblast-like cells were accelerated by Dex and cell proliferation activities, ALP activity of Dex group showed lower than control group. Dex was considered that it did suppress initial growth, but accerelate mineralization of osteoblast-like cells.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.153-159
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• 2010

Recently, it has been reported that mechanical stimulation takes a role in improving cell growth. Also, became generally known that skeletal system as bone or cartilage tissues take influence of compression loading. In this study, we fabricated a custom-made bioreactor and analyzed that conditions of compressive loading would influence cell growth. To compare the effect of intermittent compressive loading on cell-encapsulated agarose scaffold, we cultured preosteoblast cell (MC3T3-E1 cells) statically and dynamically. And dynamic culture conditions were produced by changing parameters such as the iteration time and interval delay time. Also, cellencapsulated agarose scaffold were subjected to 10 % dynamic compressive strain at 1㎐ frequency for 7 days. After cell culture, cell proliferation was assessed with PI stain assay for fluorescence images and flow cytometry (FACS).

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.20-20
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• 2011

It has been known that, under certain conditions, application of low-temperature atmospheric-pressure plasmas can enhance proliferation of cells. In this study, conditions for optimal cell proliferation were examined for various cells relevant for orthopaedic applications. Plasmas used in our experiments were generated by dielectric barrier discharge (DBD) with a helium flow (of approximately 3 litter/min) into ambient air at atmospheric pressure by a 10 kV~20 kHz power supply. Such plasmas were directly applied to a medium, in which cells of interest were cultured. The cells examined in this study were human synoviocytes, rat mesenchymal stem cells derived from bone marrow or adipose tissue, a mouse osteoblastic cell line (MC3T3-E1), a mouse embryonic mesenchymal cell line (C3H-10T1/2), human osteosarcoma cells (HOS), a mouse myoblast cell line (C2C12), and rat Schwann cells. Since cell proliferation can be enhanced even if the cells are not directly exposed to plasmas but cultured in a medium that is pre-treated by plasma application, it is surmised that long-life free radicals generated in the medium by plasma application stimulate cell proliferation if their densities are appropriate. The level of free radical generation in the medium was examined by dROMs tests and correlation between cell proliferation and oxidative stress was observed. Other applications of plasma medicine in orthopaedics, such as plasma modification of artificial bones and wound healing effects by direct plasma application for mouse models, will be also discussed. The work has been done in collaboration with Prof. H. Yoshikawa and his group members at the School of Medicine, Osaka University.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.137-140
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• 2003

Recently, CG (Conjugate Gradient) scheme for the optimization of the Rayleigh quotient has been proven a very attractive and promising technique for interior eigenvalues for the following eigenvalue problem, Ax＝λx (1) The given matrix A is assummed to be large and sparse, and symmetric. Also, the method is very amenable to parallel computations. A proper choice of the preconditioner significantly improves the convergence of the CG scheme. We compare the parallel preconditioners for the computation of the interior eigenvalues of a symmetric matrix by CG-type method. The considered preconditioners are Point-SSOR, ILU (0) in the multi-coloring order, and Multi-Color Block SSOR (Symmetric Succesive OverRelaxation). We conducted our experiments on the CRAY­T3E with 128 nodes. The MPI (Message Passing Interface) library was adopted for the interprocessor communications. The test matrices are up to $512{\times}512$ in dimensions and were created from the discretizations of the elliptic PDE. All things considered the MC-BSSOR seems to be most robust preconditioner.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.448-468
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• 1996

To maintain its functional integrity, bone is continuously remodelled by a process involving resorption by osteoeclasts and formation by osteoblasts, In order to respond to changes in the physical environment or to trauma with the relevant action, this process is strictly regulated by locally synthesized or systemic fators, Prostaglandin $E_2(PGE_2$) is perhaps one of the best studied factors, having been known to affect bone cell function for several decades.$PGE_2$ has both anabolic and catabolic activities. Excess of $PGE_2$ has been implicated in a number of pathological states associated with bone loss in a number of chronic inflammatory conditions such as periodontal disease and rheumatoid arthritis. $PGE_2$ and other arachidonic acid metabolites have been shown to be potent stimulators of osteoclastic bone resorption in organ culture. The anabolic effects of $PGE_2$ were first noticed when an increase in periosteal woven bone formation was seen after the infusion of $PGE_2$ into infants in order to prevent closure of the ductus arteriosus. The cellular basis for the catabolic actions of $PGE_2$ has been well characterized. $PGE_2$increases osteoclast recruitment in bone marrow cell cultures. Also $PGE_2$ has a direct action on osteoclast serving to inhibit activity and can also indirectly activate osteoclast via other cells in the vicinity, presumably osteoblast. The cellular mechanisms for the anabolic actions of $PGE_2$ are not nearly so well understood. The purpose of this paper was to study the effects of $PGE_2$ and dibutyl(DB)cAMP on osteoblastic clone MC3T3El cells and on the generation of osteoclasts from their precursor cells. The effect of $PGE_2$ and DBcAMP on the induction of alkaline phoaphatase(AlP) was investigated in osteoblastic clone MC3T3El cells cultured in medium containing 0.4% fetal bovine serum. $PGE_2$ and DBcAMP stimulated ALP activity and MTT assay in the cells in a dose-dependent manner at concentrations of lO-SOOng/ml. Cycloheximide, protein synthesis inhibitor, inhibited the stimulative effect of $PGE_2$ and DBcAMP on ALP activity in the cells. $PGE_2$also increased the intracellular cAMP content in a dose-dependent fashion with a maximal effect at 500ng/ml. The effect of $PGE_2$ on the generation of osteoclasts was investigated in a coculture system of mouse bone marrow cells with primary osteoblastic cells cultured in media containing 10% fetal bovine serum.After cultures, staining for tartrate-resistant acid phosphatase(TRAP)-marker enzyme of osteoclast was performed. The TRAP(+) multinucleated cells(MNCs), which have 3 or more nuclei, were counted. More TRAP(+) MNCs were formed in coculture system than in control group. $PGE_2(10^{-5}10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in culture. $PGE_2(10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in coculture of osteoblastic clone MC3T3E1 cells This results suggest that $PGE_2$ stimulates the differentiation of osteoblasts and generation of osteoclast, and are involved in bone formation, as well as in bone resorption.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.216-229
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• 1996

Interferon(IFN) is a sort of glycoproteins that are produced by activated lymphocyte, monocyte and fibroblast. IFN has anti-viral effects, immuno-defensive mechanism and regulating properties to the several kinds of cells that includes affect on the bone formation and resorption. The effect of IFN on the osteoclast & other tissue cells has been studied in a number of researchers with the limited reports on the osteoblast. The purpose of this study was to evaluate the effects of IFN on the osteoblastic function. The MC3T3/El cell(Mouse osteoblast) was incubated in ${\alpha}-minimum$ essential medium containing 10% FBS. To detect the cytotoxic effect of $IFN-{\gamma}$ on osteoblast, the cells were cultured in 96-well plate to which $IFN-{\gamma}$ of various concentrations were added for 2 days. After staining with trypan blue, total cells and living cells were counted under microscope. To determine the activity of alkaline phosphataset(ALP), various concentrations of $IFN-{\gamma}$ were treated to culture medium, and biochemical assay was performed. $IFN-{\gamma}$ and $IFN-{\gamma}$ plus cycloheximide were added to culture medium separately and then ALP activity were determined. To detect the effect of the $IFN-{\gamma}$ on the bone formation of osteoblast, long-term culture was performed, and calcified nodule formation were observed using von Kossa's staining. After the addition of $IFN-{\gamma}$ with various concentrations to the medium, no cytotoxic effect of $IFN-{\gamma}$ was detected at any concentration. The significant increase in ALP activity of osteoblast were found the concentration of $IFN-{\gamma}$ 500-2500U/ml and the culture time of 24-48 hours respectively. The enhancement of ALP activity by $IFN-{\gamma}$ of osteoblast was decreased significantly by the treatment of cycloheximide. After long-term culture of osteoblast, the nodule formation was found to be increased in number and density by the addition of 500 U/ml $IFN-{\gamma}$. These results suggest that $IFN-{\gamma}$ was affected on the bone formation of osteoblast. Forthemore this kind of study or $IFN-{\gamma}$ to osteoblast will be held continuously.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.195-206
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• 2003

Several factors can affect the formation of bone tissues surrounding implants. One of the factors is electrical stimulation. It is known to change the movement of cells, form and destroy cells, and alter concentration and chemical component of soft tissues and bones. The effect of electrical stimulation on bone formation can vary according to the intensity of electric currents, stimulating time, the method of sending electric currents, and tissues and cells currents are applied to. This study examines how various enviroments affect osteoblasts. (1) effect on osteoblast with varying intensity of currents Osteoblast-like cells were raised on four plates where implants can be placed. A constant current sink (MC3T3-E1) that can adjust the intensity and stimulating time of electric currents was used. The four plates were stimulated with $0{\mu}A$, $10{\mu}A$, $20{\mu}A$, and $40{\mu}A$, respectively. After 24 hours of stimulation, the number and distribution of cells surrounding implants were examined. (2) effect on osteoblast with varying conditions The 3 study was performed with same method. (1) The change of attached cell number 72-hour after application of various currents (2) The change of attached cell number 72-hour after application of various interval (3) The comparison of attached cell number by implant surface texture The following are the results: 1. The distribution and density of cells surrounding implant is highest under the intensity of electric currents of $20{\mu}A$. 2. The number of cells attached implants is highest under the intensity of electric currents of $20{\mu}A$. 3. The number of cells attached implants is highest under continous electric currents 4. The number of cells attached implants is not different by implant surface texture.