• Reproductive and Developmental Biology
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• v.34 no.1
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• pp.1-6
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• 2010

Mesenchymal stem cells (MSCs) have the multipotent capacity and this potential can be applied for obtaining valuable cell types which can use for cell therapy on various regenerative diseases. However, insufficient availability of cellular source is the major problem in cell therapy field using adult stem cell sources. Recently, human embryonic stem cells (hESCs) have been highlighted to overcome a limitation of adult cellular sources because they retain unlimited proliferation capacity and pluripotency. To use of hESCs in cell therapy, above all, animal pathogen free culture system and purification of a specific target cell population to avoid teratoma formation are required. In this study, we describe the differentiation of a mesenchymal stem cell-like cells population from feeder-free cultured hESCs(hESC-MSCs) using direct induction system. hESC-MSCs revealed characteristics similar to MSCs derived from bone marrow, and undifferentiated cell markers were extremely low in hESC-MSCs in RT-PCR, immunostaining and FACS analyses. Thus, this study proffer a basis of effective generation of specialized human mesenchymal stem cell types which can use for further clinical applications, from xenofree cultured hESCs using direct induction system.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.277-290
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• 2008

The process of wound repair involves an ordered sequence of events such as overlapping biochemical and cellular events that, in the best of circumstances, result in the restoration of both the structural and functional integrity of the damaged tissue. An important event during wound healing is the contraction of newly formed connective tissues by fibroblasts. The polypeptide growth factors, like transforming growth factor-${\beta}$(TGF-${\beta}$, insulin-like growth factor I (IGF- I) and epidermal growth factor (EGF), play very important mediator roles in the process of wound contraction. Deer antlers, as models of mammalian regeneration, are cranial appendages that develop after birth as extensions of a permanent protuberance (pedicle) on the frontal bone. Antlers contain various growth factors which stimulate dermal fibroblast growth. They are involved in digestion and respiration and are necessary for normal wound healing and skin health. In order to investigate and evaluate the effects of red deer antlers on skin wound site, the speed of full-thickness skin wound healing and the expression of IGF-I, TGF-${\beta}$ and EGF in skin wounds, three groups of skin full-thickness rat models with a high concentration of antler ointment, a low concentration of antler ointment and without antler ointment were compared. At post-injury days 0, 2, 4, 8, 16, 20, 32, 40 and 60, the skin wound area was measured, the expressions of IGF-I, TGF- ${\beta}$ and EGF mRNA were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and collagen formation by sirius red dye and the localization of IGF-I, TGF-${\beta}$ and EGF peptides were inspected by histological immunohistochemical techniques. Wound healing was significantly more rapid in antler treated skins. In addition, the wound treated with a high concentration antler ointment, a low concentration antler ointment, and the control closed completely at post-injury day 40, day 44 and day 60, respectively. Via RT-PCR, the expressions of IGF-I (day 8 and day 16), TGF-${\beta}$(day 8, day 16 and day 20) and EGF (day 4, day 8, day 16, and day 32) were obviously up-regulated in high concentration antler-treated skins compared to control skins. Similar results could be seen in the histological detection of collagen dye and immunohistochemical methods using the corresponding polyclone antibodies of IGF-I, TGF-${\beta}$ and EGF. These results illustrate that antlers stimulate and accelerate the repair of cutaneous wounds.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.287-293
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• 2009

Long-term treatment with glucocorticoid leads to the development of osteoporosis and osteonecrosis. In contrast to the marked inhibitory effect of pharmacological doses of glucocorticoids on bone formation, the relationship between physiological concentrations of glucocorticoids and osteoprogenitor cell proliferation and phenotypes has not been elucidated yet. In addition, the effects of dexamethasone treatment on the proliferation and osteoblastic differentiation of osteoprogenitor cells are also controversial. The purpose of this study was to examine the effects of dexamethasone on the proliferation and osteoblastic differentiation of periosteal-derived cells. Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were further cultured for 21 days in the osteogenic induction medium with different dexamethasone concentrations of 0, 10, and 100 nM. The proliferation and osteoblastic phenotypes of periosteal-derived cells were promoted in dexamethasone-treated cells than in untreated cells. Among the dexamethasone-treated cells, cell proliferation was slightly greater in 10 nM dexamethasone-treated cells than in 100 nM dexamethasone-treated cells. Histochemical staining and the bioactivity of alkaline phosphatase (ALP) were higher in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. Similarly, von Kossa-positive mineralization nodules and calcium content were also more evident in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. These results suggest that dexamethasone enhances the in vitro osteoblastic differentiation of periosteal-derived cells. The present study also demonstrates that higher dexamethasone concentrations reduce the in vitro proliferation of periosteal-derived cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.294-298
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• 2009

Purpose: The development of a microvascularization is important for the homeostasis of normal bone. Vascular endothelial growth factor (VEGF) is one of the most important factors in vessel formation. The purpose of this study was to examine VEGF-related autocrine growth in periosteal-derived cells. Materials and methods: Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured for 21 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and $\beta$-glycerophosphate. Results: The expression of four VEGF isoforms and VEGFRs was observed in periosteal-derived cells. Treatment with cultures with VEGFR-1 and VEGFR-2 Kinase Inhibitor inhibited osteoblastic differentiation and alkaline phosphatase (ALP) activity of periosteal-derived cells. In addition, exogenous VEGF treatment increased calcium content in the periosteal-derived cells. Conclusion: These results suggest that VEGF might act as an autocrine growth molecule during osteoblastic differentiation of cultured human periosteal-derived cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.718-724
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• 2008

Tooth impaction is a frequently observed eruption anomaly in pediatric dental practice. Young patients with impacted or unerupted teeth have more prediction for dentigerous cyst formation. Dentigerous cyst presents radiographic features, unilocular or multilocular radioluscency. Cysts occur most frequently in the premolar region except third molar. Dentigerous cysts can grow to a considerable size, and large cysts may be associated with a painless expansion of the bone in the involved area. Extensive lesions may result in facial asymmetry, osseous destruction, root resorption of proximal teeth and displacement of associated tooth. The nature of the causative tooth influences the type of surgical treatment required for the dentigerous cyst. If the cyst is associated with a supernumerary or wisdom tooth, complete enucleation of the cyst along with extraction of tooth may be the first treatment choice. Otherwise, preservation of the associated teeth should be considered to prevent a young patient from psychological and mental trauma because of the loss of tooth. We should consider the degree of tooth displacement, osseous destruction and growth pattern of oromaxillofacial area when planning treatment. Thus a proper and logical treatment planning can help a proper growth and development of oromaxillofacial area and can save the patient from a psychological and mental trauma. This report describes 4 cases of the management of impacted premolars and molars associated with dentigerous cysts in children.

• Journal of Technologic Dentistry
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• v.30 no.1
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• pp.25-31
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• 2008

Cp-Ti and Ti-6Al-4V alloys commonly used dental implant materials, particularly for orthopaedic and osteosynthesis because of its suitable mechanical properties and excellent biocompatibility. This alloys have excellent corrosion behavior in the clinical environment. The first factor to decide the success of dental implantation is sufficient osseointegration and high corrosion resistance between on implant fixture and its surrounding bone tissue. In this study, in order to increase corrosion resistance and biocompatibility of Cp-Ti and Ti-6Al-4V alloy that surface of manufactured alloy was coated with TiN by RF-magnetron sputtering method. The electrochemical behavior of TiN coated Cp-Ti and Ti-6Al-4V alloy were investigated using potentiodynamic (EG&G Co, PARSTAT 2273. USA) and potentiostatic test (250mV) in 0.9% NaCl solution at 36.5 $\pm$ 1$^{\circ}C$. These results are as follows : 1. From the microstructure analysis, Cp-Ti showed the acicular structure of $\alpha$-phase and Ti-6Al-4V showed the micro-acicular structure of ${\alpha}+{\beta}$ phase. 2. From the potentiodynamic test, Ecorr value of Cp-Ti and Ti-6Al-4V alloys showed -702.48mV and -319.87mV, respectively. Ti-6Al-4V alloy value was higher than Cp-Ti alloy. 3. From the analysis of TiN and coated layer, TIN coated surface showed columnar structure with 800 nm thickness. 4. The corrosion resistance of TiN coated Cp-Ti and Ti-6Al-4V alloys were higher than those of the non-coated Ti alloys in 0.9% NaCl solution from potentiodynamic test, indicating better protective effect. 5. The passivation current density of TiN coated Cp-Ti and Ti-6Al-4V alloys were smaller than that of the noncoated implant fixture in 0.9% NaCl solution, indicating the good protective effect resulting from more compact and homogeneous layer formation.

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.35-44
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• 2007

Periodontal ligament (PDL) is the connective tissue located between the tooth root and alveolar bone. In a previous study, PDLs22 was isolated as a PDL-specific gene by using subtractive hybrid-ization between cultured PDL fibroblasts and gingival fibroblasts. It was also suggested that PDLs22 plays important roles in the development, differentiation and maintenance of periodontal tissues. However, little is known about functional study of PDLs22 using recombinant protein in PDL fibroblast differentiation and periodontium formation. In this study, in order to produce the PDLs22 recombinat protein, PDLs22 expression vector were constructed and expressed its protein in various host cell and temperature conditions. The results were as follows: 1. PDLs22 protein was not strongly expressed In the induction system using pRSET-PDLs22 construct. 2. When the BL21(DE3) pLysS was used as a expression host, PDLS22 protein was strongly ex-pressed in the induction system using pHCEIIBNd-PDLs22 construct. 3. The PDLs22 protein was recognized at a molecular weight of 28 kDa in western blots. 4. Almost of the expressed PDLs22 protein was not soluble and observed like as inclusion body. 5. The protein solubility was not improved after modification of induction time and temperature during PDLs22 protein production. In this study, the system for the PDLs22 protein production was connstructed. However, the re-results suggest that further studies will be needed to produce the considerable amount of PDLs22 re-combinat protein, which can use for the periodontal regeneration.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.166-175
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• 2016

There is no genetic activity information with the functions of dental pulp and periodontal ligament in human. The purpose of this study was to identify the gene-expression profiles of, and the molecular biological differences between periodontal ligament and dental pulp obtained from human permanent teeth. cDNA microarray analysis identified 347 genes with a fourfold or greater difference in expression level between the two tissue types 83 and 264, of which were more plentiful in periodontal ligament and dental pulp, respectively. Periodontal ligament exhibited strong expression of genes related to collagen synthesis (FAP), collagen degradation (MMP3, MMP9, and MMP13), and bone development and remodeling (SSP1, BMP3, ACP5, CTSK, and PTHLH). Pulp exhibited strong expression of genes associated with calcium ions (CALB1, SCIN, and CDH12) and the mineralization and formation of enamel and dentin (SPARC/SPOCK3, PHEX, AMBN, and DSPP). Among these genes, SPP1, SPARC/SPOCK3, AMBN, and DSPP were well known in dental research. However, the other genes are the newly found and it may help to find a good source of regenerative therapy if further study is performed.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.456-463
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• 2009

Cleidocranial dysplasia(CCD) is a congenital disorder of skeletal and dental abnormality, which is a mesodermal dysfunction influencing many tisssues and organs. Skeletal abnormalities in CCD are delayed closure of cranial suture and fontanelle, presence of wormian bone and clavicle aplasia. CCD also has an effect on long bones, phalanges, spine, pelvis, muscles, and central nervous system. Dental manifestations include retention of deciduous teeth, multiple supernumerary teeth, delayed eruption or impaction of permanent teeth and formation of cysts around nonerupted teeth. However, due to lack of any substansive medical or physical disability, diagnosis is often late, thereby causing masticatory and psychological problems caused by delayed eruption of permanent teeth after exfoliation of deciduous teeth. For this reason, CCD requires early diagnosis, and the patient's appearance must be improved. Also, provision for a functional masticatiory mechanism by treatment of surgical removal of supernumerary teeth followed by orthodontic eruption of the natural permanent teeth at an adequate time is necessary.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1106-1115
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• 2009

Mori Ramulus has multiple applications in Korean traditional medicine prescription because it has antioxidant and anti-inflammatory effects by reducing macrophage activities. Yet, no studies on the anti-arthritic activity of EMR (extract of Mori Ramulus) have been reported in vitro and in vivo. Rheumatoid arthritis (RA) is a systemic autoimmune disease with chronic inflammation characterized by hyperplasia of synovial cells in affected joints, which ultimately leads to the destruction of cartilage and bone. Because collagen-induced arthritis (CIA) is similar to RA in pathological symptoms and immune reactions, there have been several reports concerning RA using CIA mouse model. Here, we investigated the effects of Mori Ramulus on RA using CIA mice. The importance of CD4+ Th1 cells in RA progress was previously indicated and studies further showed that Th17 cells play a prime role in severity of disease. Accordingly, the present study was focused on CIA associated with CD4+ Th1 cells and Th1 7 cells. DBA/1OlaHsd mice were immunized with bovine type II collagen (CII). After a second collagen immunization, mice were treated with EMR once a day for 4 weeks. The severity of arthritis within the paw joints was evaluated by histological assessment of cartilage destruction and pannus formation. Immune cells in peripheral blood mononuclear cells (PBMC), draining lymph node (DLN) and paw joints, cytokine production and gene expression were assessed from CIA mouse using ELISA, FACS and real-time PCR analysis. Administration of EMR significantly suppressed the progression of CIA and inhibited the production of TNF-$\alpha$, IL-6 and IL-17 in the serum. The erosion of cartilage was dramatically reduced in mouse knees after treatment with EMR. In conclusion, our results demonstrate that EMR significantly suppressed the progression of CIA and that this action was mediated by the decreased production of TNF-$\alpha$, IL-6, IL-17 and collagen II-specific antibody in the serum. EMR suppressed Th17 cells and reduced level of IL-6 via B cell suppression, and thus, the levels of autoantibodies produced from B cells were decreased. Furthermore, EMR suppressed NKT cells which directly stimulate B cells and develop imbalance of Th1/Th2 cell. Oral administration of EMR (100 mg/kg or 200 mg/kg) significantly suppressed the progression of CIA, which is comparable to that of methotrexate (MTX, 0.3 mg/kg) used as a positive control. We are currently studying the mechanism underlying the therapeutic role for EMR in CIA mice.