• Applied Microscopy
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• v.46 no.1
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• pp.58-66
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• 2016

Thymosin ${\beta}4$ ($T{\beta}4$) has been recently reported to play a role in dentinogenesis by regulating the expression of dentin matrix proteins. Based on previous studies, it is hypothesized that $T{\beta}4$ is associated with the formation of the enamel matrix and thus plays an important role in ameloblast. However, there is no report on the function of $T{\beta}4$ during tooth development so far. Therefore, in this study, we aimed to investigate the expression of $T{\beta}4$ and its function in ameloblasts during mouse tooth development. $T{\beta}4$ was expressed strongly in the tooth bud at the bud stage and in the dental lamina and oral epithelium at the cap stage. In advanced bell stage at postnatal day 4, large elongated ameloblasts were observed and the expression of the $T{\beta}4$ protein was the highest, with the enamel being was thicker than that in the early bell stage. The length of ameloblasts increased from the presecretory to the secretory stage and decreased from the maturation to the protective stage. These results suggest that $T{\beta}4$ participates not only in the proliferation of oral epithelial cells during the early stage of tooth development but also regulates enamel protein secretion in ameloblasts and enamel mineralization.

• Korean Journal of Materials Research
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• v.16 no.10
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• pp.606-613
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• 2006

This study was purposed to evaluate the influence of anodically oxidized film on titanium (Ti) onto MG-63 osteoblast-like cell attachment and activity. Only scratch lines created by polishing were seen in ASR and ANO-1 groups. About $1.5{\mu}m$-thick homogeneous oxide film which has pores of about $0.5{\mu}m$ diameter were formed in ANO-12. The crystalline structure of the oxide films formed by anodization in phosphoric acid electrolyte was $TiP_2O_7$. The total protein amounts of ANO-1 and ANO-12 groups showed higher values of maximum protein amount than that of AS-R group. At 3 days of incubation, total protein amount showed higher value in ANO-2 when comparing to that of AS-R (p<0.05). Based on the results of ALPase activity test, the degree of MG-63 cell differentiation for initial mineralization matrix formation was similar. For all the test groups after 1 day of incubation, MG-63 cells grew healthily in mono-layer with dendritic extensions. After incubation for 3 days, the specimen surfaces were covered more densely by cells, and numerous micro filaments were extruding to the extracellular matrix.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.663-666
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• 2007

A 16-year-old female Poodle with multiple mammary masses was referred to the Veterinary Medical Teaching Hospital of Seoul National University. Radiographic finding indicated a round mass of soft tissue density at the ventral portion of the 4th-7th sternum, which was 7 cm in diameter and presented multiple mineralization within the mass. Cytologically, aspirate of the mammary mass was moderately cellular and revealed well-differentiated osteoblasts with moderately basophilic cytoplasm, various sized and eccentrically placed nuclei and distinct nucleoli. Osteoblasts interspersed with osteoid-suspected pink-staining intercellular matrix. Some cells displayed malignant features such as macronuclei, macronucleoli, binucleation, abnormal mitotic figures, anisocytosis and anisokaryosis. On which the mass was diagnosed as osteosarcoma. Histopathologic examinations of the mass were compatible with a diagnosis of osteosarcoma. The patient was treated with surgery alone. The patient died 45 days later from surgery.

• Journal of Energy Engineering
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• v.27 no.3
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• pp.48-56
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• 2018

The shell waste biomineralization process has known a tremendous metamorphosis and also the nanostructure with the identification of matrix proteins in oyster shells. However, proteins are represented in minor shell components and they are the major macromolecules that control biocrystal synthesis. Aragonite and calcite were derived from molluscan shells and evaluated the source of carbonate minerals and it helps for the formation of limestone. The oyster shell wastes are large and massive. The paleoecological study of oyster beds has discovered a near-shore and thin Upper Rudeis formation with storm influence during the accumulation of oysters with highly altered by disarticulation, bioerosion, and encrustation. It is possible even in the Paleozoic mollusks provided sufficient carbonate entirely to the source of microcrystalline of limestone. The present review is to discuss paleoecologically a number of oyster shell beds accumulated and sediment to form the different types of limestone during the Middle Miocene time.

• Journal of Chest Surgery
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• v.24 no.8
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• pp.802-806
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• 1991

Primary neoplasms of the ribs and sternum are rare. Most primary bony chest wall neoplasms are malignant, and chondrosarcoma is the most common malignancy in this location The etiology of chondrosarcoma is unknown. Definitive diagnosis of chondrosarcoma can only be made pathologically. The natural history of chest wall chondrosarcoma is one of slow growth and local recurrence. Most tumors of the sternum require wide resection and reconstruction procedures, with potentially serious postoperative problems. Advances in chest wall reconstruction primarily through refinement in muscle transposition and clarification of the functional anatomy and blood supply of trunk muscles, has resulted in a more aggressive resection of the these tumors . Recently we experienced a case with chondrosarcoma of the sternum. A 56 year-old man was admitted to our hospital due to painless, slowly enlarging mass at the left sternoclavicular junctional area. The chest radiograph strongly suggested an underlying cartilaginous neoplasm owing to the appearance of typical flocculent and curvilinear calcifications within the lesion. On CT of the chest, the tumor exhibited a scalloped or lobulated contour, hypodensity of the nonmineralized component in comparison to adjacent muscle, and characteristic stippled cartilaginous matrix mineralization, also typical for cartilaginous neoplasm. The patient underwent wide resection of the chest wall tumor include with a 2-3cm margin of normal tissue on all sides and the thoracic skeletal defect was reconstructed with polytetrafluoroethylene [Gore-Tex] soft-tissue patch. Soft tissue reconstructive procedure was done with the pectoralis major muscle transposition. The patient had an uneventful postoperative course and discharged without adjuvant treatment such as radiation and chemotherapy.

• Imaging Science in Dentistry
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• v.44 no.2
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• pp.165-169
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• 2014

An osteolytic lesion with a small central area of mineralization and sclerotic borders was discovered incidentally in the clivus on the cone-beam computed tomography (CBCT) of a 27-year-old male patient. This benign appearance indicated a primary differential diagnosis of non-aggressive lesions such as fibro-osseous lesions and arrested pneumatization. Further, on magnetic resonance imaging (MRI), the lesion showed a homogenously low T1 signal intensity with mild internal enhancement after post-gadolinium and a heterogeneous T2 signal intensity. These signal characteristics might be attributed to the fibrous tissues, chondroid matrix, calcific material, or cystic component of the lesion; thus, chondroblastoma and chondromyxoid fibroma were added to the differential diagnosis. Although this report was limited by the lack of final diagnosis and the patient lost to follow-up, the incidental skull base finding would be important for interpreting the entire volume of CBCT by a qualified oral and maxillofacial radiologist.

• Restorative Dentistry and Endodontics
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• v.37 no.4
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• pp.194-200
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• 2012

Objectives: New resin cement (NRC) has been developed as a root repairing material and the material is composed of organic resin matrix and inorganic powders. The aim of this study was to compare the rat subcutaneous tissue response to NRC and mineral trioxide aggregate (MTA) cement and to investigate the tissue toxicity of both materials. Materials and Methods: Sixty rats received two polyethylene tube-implants in dorsal subcutaneous regions, MTA and NRC specimens. Twenty rats were sacrificed respectively at 1, 4 and 8 wk after implantation and sectioned to 5 ${\mu}m$ thickness and stained with Hematoxylin-Eosin (H-E) or von-Kossa staining. The condition of tissue adjacent to the implanted materials and the extent of inflammation to each implant were evaluated by two examiners who were unaware of the type of implanted materials in the tissues. Data were statistically analyzed with paired t-test (p < 0.05). Results: In specimens implanted with both NRC and MTA, severe inflammatory reactions were present at one wk, which decreased with time. At eighth wk, MTA implanted tissue showed mild inflammatory reaction, while there were moderate inflammatory reactions in NRC implanted tissue, respectively. In NRC group, von-Kossa staining showed more calcification materials than MTA group at eighth wk. Conclusions: It was concluded that the calcium reservoir capability of NRC may contribute to mineralization of the tissues.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.437-444
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• 2006

This study was aimed to elucidate the biological function of OD314 (Apin protein), which is related to ameloblast differentiation and amelogenesis. Apin protein, calcifying epithelial odontogenic (pindborg) tumors (CEOTs)-associated amyloid, were isolated from CEOTs, and has similar nucleotide sequences to OD314. We examined expression of the OD314 mRNA using in-situ hybridization during tooth development in mice. Expression of OD314 and several enamel matrix proteins were examined in the cultured ameloblast cell line up to 28 days by reverse transcription-polymerase chain reaction (RT-PCR) amplification. After inactivation and over-expression of the OD314 gene in ameloblast cell lines using U6 vectordriven RNA interference and CMV-OD314 construct, RT-PCR were performed to evaluate the effect of the OD314 during amelogenesis. The results were as follows: 1. In in-situ hybridization, OD314 mRNAs were more strongly expressed in ameloblast than odontoblast. 2. When ameloblast cells were cultured in the diffcrentiation and mineralization medium for 28 days, the tuftelin mRNA expression was maintained from the beginning to day 14, and then gradually decreased to day 28. The expressions of amelogenin and enamelin were gradually decreased according to the ameloblast differentiation. 3. Inactivation of OD314 by U6-OD314 siRNA construct down-regulated the expression of OD314, MMP-20, and tuftelin, whereas over-expression of OD314 by CMV-OD314 construct up-regulated the expression of OD314 and MMP-20 without change in tuftelin. These results suggest that OD314 is considered as an ameloblast-enriched gene and may play the important roles in ameloblast differentiation and mineralization.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.16-23
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• 2005

It is commonly acknowledged that bone morphogenic protein (BMP-2) functions as a potential osteogenic inducer in bone formation. Recently, several papers reported that bone marrow-derived stem cell (BMSC) from human is not responsive to BMP-2 in comparison to high capacity of BMP-2 in the osteoinduction of stromal cell derived from bone marrow of rodent animals such as rat or mouse. In this study, we characterized BMSC derived from 11 years old donor for the responsiveness to rhBMP-2, dexamethasone (Dex) and 1,25-dihydroxyvitamin D (vitamin D), in order to analyze their function in the early osteogenesis. The effect of over mentioned agents was evaluated by means of assessing alkaline phosphatase (ALP) activity/staining, RT-PCR analysis and von Kossa staining. In addition, we analyzed the meaning of expressed several osteoblastic markers such as alkaline phosphatase, collagen typeI, osteopontin, bone sialoprotein and osteocalcin with relation to either differentiation or mineralization. Only in the presence of Dex, human BMSC could commit osteoblastic differentiation and matrix mineralization, and either BMP-2 or vitamin D treatment was not able to induce. But BMP-2 or Vitamin D showed potential synergy effect with Dex. ALP and bone sialoprotein were clearly expressed in response of Dex treatment compared to weak expression of osteopontin in early osteogenesis. Therefore, we expect that this study will contribute partly to elucidiating early osteogenesis mechanism in human, but variations among bone marrow donors must be considered through further study.

• Molecules and Cells
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• v.41 no.12
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• pp.1016-1023
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• 2018

Regenerative orthopedics needs significant devices to transplant human stem cells into damaged tissue and encourage automatic growth into replacements suitable for the human skeleton. Soft biomaterials have similarities in mechanical, structural and architectural properties to natural extracellular matrix (ECM), but often lack essential ECM molecules and signals. Here we engineer mineralized polysaccharide beads to transform MSCs into osteogenic cells and osteoid tissue for transplantation. Bone morphogenic proteins (BMP-2) and indispensable ECM proteins both directed differentiation inside alginate beads. Laminin and collagen IV basement membrane matrix proteins fixed and organized MSCs onto the alginate matrix, and BMP-2 drove differentiation, osteoid tissue self-assembly, and small-scale mineralization. Augmentation of alginate is necessary, and we showed that a few rationally selected small proteins from the basement membrane (BM) compartment of the ECM were sufficient to up-regulate cell expression of Runx-2 and osteocalcin for osteoid formation, resulting in Alizarin red-positive mineral nodules. More significantly, nested BMP-2 and BM beads added to a non-union skull defect, self-generated osteoid expressing osteopontin (OPN) and osteocalcin (OCN) in a chain along the defect, at only four weeks, establishing a framework for complete regeneration expected in 6 and 12 weeks. Alginate beads are beneficial surgical devices for transplanting therapeutic cells in programmed (by the ECM components and alginate-chitosan properties) reaction environments ideal for promoting bone tissue.