• The korean journal of orthodontics
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• v.25 no.6 s.53
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• pp.697-704
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• 1995

Chicken calvarial bone is known to contain various cell types, but their exact composition is unknown. By characterizing the chicken calvarial bone biochemically, it can be used to study biochemical, histochemical actions of bone cells in general. Calvaria of 18-day-old white leg horn embryo was aseptically dissected and bone cell populations were isolated by sequential enzymatic digestion. Histochemical study for osteoclast-like bone cell. population was performed with tartrate resistant acid phosphatase(TRAP) stain and for osteoblast-like bone cell population, alkaline phosphatase(ALP) stain was performed. Biochemical study for osteoblast-like bone cell population was performed using alkaline phosphatase(ALP) assay. Following conclusions were obtained from this study. 1. TRAP positive multi and mononuclear cells were mostly observed in group I and II, indicating that osteoclast-like bone cell population is mostly found in these groups. 2. All the cultured groups showed almost equal ALP activities and were positive for ALP stain, indicating that osteoblast-like bone cell population is evenly dispersed in all culture groups. 3. Experimental group treated with $1,25(OH)_{2}D_3$ showed increase in ALP activity in contrast to the control group, confirming previous studies that $1,25(OH)_{2}D_3$ increases ALP activities in in vitro bone cultures. 4. Results from von Kossa's stain indicated that in vitro bone formation had occured after 3 weeks of culture with beta-glycero phosphate.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.343-346
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• 2005

It has been established that a graft of fibroblasts is able to improve wound healing. However, there has been no research on the effect of a graft of bone marrow stromal cells on wound healing. The wound healing process requires cell proliferation and production of extracellular matrix and various growth factors. The purpose of this study was to compare the abilities of human fibroblasts and bone marrow stromal cells, which contains mesenchymal stem cells, to proliferate and to produce collagen. Human bone marrow stromal cells and fibroblasts were isolated from bone marrow and dermis of the same patients and grown in culture respectively. Cell proliferation and production of type I collagen by human bone marrow stromal cells and dermal fibroblasts were examined by MTT method and by ELISA of cell culture media on day 1, 3, and 5 days post-incubating. The human bone marrow stromal cells showed 11-17% higher cell proliferation than fibroblasts at each time interval. The levels of type I collagen in the human bone marrow stromal cell group was also significantly higher than those in the fibroblast group. The results indicate that the grafts of human bone marrow stromal cells can show more promising effect than that of fibroblasts for healing of chronic wounds.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.933-943
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• 1994

The present study was undertaken to determine the effect of tensile force on DNA and protein biosynthesis in bone cells, and to identify the cell type(s) which primarily respond to external physical force among the heterogenous bone cell populations. As a prerequisite for this study, two bone cell populations which retain fibroblastic and osteoblastic feature were isolated from fetal rat calvaria with sequential enzyme digestion scheme. Tensile force was delivered to each bone cell population by two acrylic resin plates connected with a orthodontic expansion screw during culture period. Rate of DNA and protein synthesis in each bone cell population were assessed by the incorporated radioactivity of $[^3H]-thymidine$ into DNA and $[^3H]-proline$ into fraction of collagenase-digestible protein and noncollagenous protein, respectively. DNA synthesis of osteoblast-like calvarial cell populations was increased significantly by the application of tensile force for 24 hours. In contrast, no alteration in DNA synthesis of fibroblast-like populations could be observed in response to applied force. Tensile force induced the change in protein synthesis of bone cell populations with the same pattern. Total protein and collagen synthesis were increased whithin 24 hours in osteoblast-like populations, but not in fibroblast-like populations by tensile force application. These findings indicate that physical force can affect cellullar activity of the particular cell population, not all cell Populations residing in bone and osteoblasts respond more sensitively than fibroblasts. So osteoblasts can modulate the behavior of other bone cells including osteoclasts by producing several local regulating factors of bone metabolism. In this context, preferential responsiveness of osteoblasts to applied tensile force observed in this study suggests that osteoblasts may play an important role in regulation of physical force-induced remodelling process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1055-1058
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• 2002

The movement of bone fluid from the region of the bone vasculature through the canaliculi and the lacunae of the surrounding mineralized tissue accomplishes three important tasks. First it transports nutrients to the osteocytes in the lacunae buried in the mineralized matrix. Second, it carries away the cell waste. Third, the bone fluid exerts a force on the cell process, a force that is large enough for the cell to sense. This is probably the basic mechanotrasduction mechanism in bone, the way in which bone senses the mechanical load to which it is subjected. The mechanism of bone fluid flow are described below with particular emphasis on mechanotransduction. Also described is the cell to cell communication by which higher frequency signals might be transferred, a potential mechanism in bone by which the small whole tissue strain is amplified so the bone cells can respond to it. One of the conclusions is that higher frequency low amplitude strains can maintain bone as effectively as low frequency low amplitude strains can maintain bone as effectively as low frequency high amplitude strains. This mechanism has many similarities with the mechanotransduction of acoustical signals in the ear. These conclusion leads to a paradigm shift in how to treat osteoporosis and how to cope with microgravity.

• Investigative Magnetic Resonance Imaging
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• v.20 no.2
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• pp.127-131
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• 2016

We report a case of tenosynovial giant cell tumor with severe bone erosion in the right fifth finger of a 46-year-old man. Throughout this case review, we describe the imaging findings of tenosynovial giant cell tumor with severe bone erosion and review the literatures regarding osseous lesions caused by tenosynovial giant cell tumor and their significance related to the differential diagnosis and patient treatment.

• The korean journal of orthodontics
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• v.24 no.1 s.44
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• pp.105-114
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• 1994

The movement of teeth during orthodontic treatment requires bone remodeling process of bone formation and bone resolution. To find out the changes occuring in the cell itself, mechanical stress was applied to the cell populations involved in the bone metabolism. Bone tissue cell populations were isolated from fetal rat calvaria and divided into OC and OB groups. Following results were obtained from measuring the changes in acid & alkaline phosphatease activity, cyclic AMP and $PGE_2$ production in time lapse after the application of mechanical stress. 1. In case of the marker enzyme of specific bone tissue cell, acid phosphatase activity was high in OC group and alkaline phosphatase activity was high in OB group. 2. After the mechanical stress was applied, acid phosphatase activity was decreased in both OC and OB groups and alkaline phosphatase activity was increase in OB group. 3. When the mechanical stress was applied for 15, 30 and 60 minutes, the production of $PGE_2$ increased in both OC and OB groups, as the time span increased. 4. When the mechanical stress was applied for 20 and 40 minutes, the production of $PGE_2$ increased in both OC and OB groups, as the time span increased.

• BMB Reports
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• v.48 no.12
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• pp.645-646
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• 2015

The sympathetic nervous system (SNS) or neurotransmitters in the bone marrow microenvironment has been known to regulate hematopoietic stem cell (HSC) functions such as self-renewal, proliferation and differentiation. However, the specific role of neuropeptide Y (NPY) in this process remains relatively unexplored. In this study, we demonstrated that NPY deficient mice have significantly reduced HSC numbers and impaired bone marrow regeneration due to apoptotic destruction of SNS fibers and/or endothelial cells. Moreover, NPY treatment prevented bone marrow impairments in a mouse model of chemotherapy-induced SNS injury, while conditional knockout mice lacking the Y1 receptor in macrophages did not restore bone marrow dysfunction in spite of NPY injection. Transforming growth factor-beta (TGF-β) secreted by NPY-mediated Y1 receptor stimulation in macrophages plays a key role in neuroprotection and HSC survival in the bone marrow. Therefore, this study reveals a new role of NPY in bone marrow HSC microenvironment, and provides an insight into the therapeutic application of this neuropeptide.

• International Journal of Oral Biology
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• v.44 no.2
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• pp.37-42
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• 2019

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy and an increasing global public health problem. OSCC frequently invades the jaw bone. OSCC-induced bone invasion has a significant impact on tumor stage, treatment selection, patient outcome, and quality of life. A number of studies have shown that osteoclast-mediated bone resorption is a major step in the progression of bone invasion by OSCC; however, the molecular mechanisms involved in OSCC bone invasion are not yet clear. In this review, we present the clinical types of OSCC bone invasion and summarize the role of key molecules, including proteases, cytokines, and growth factors, in the sequential process of bone invasion. A better understanding of bone invasion will facilitate the discovery of molecular targets for early detection and treatment of OSCC bone invasion.

• BMB Reports
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• v.50 no.8
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• pp.417-422
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• 2017

Cisplatin is the most effective and widely used chemotherapeutic agent for many types of cancer. Unfortunately, its clinical use is limited by its adverse effects, notably bone marrow suppression leading to abnormal hematopoiesis. We previously revealed that neuropeptide Y (NPY) is responsible for the maintenance of hematopoietic stem cell (HSC) function by protecting the sympathetic nervous system (SNS) fibers survival from chemotherapy-induced bone marrow impairment. Here, we show the NPY-mediated protective effect against bone marrow dysfunction due to cisplatin in an ovarian cancer mouse model. During chemotherapy, NPY mitigates reduction in HSC abundance and destruction of SNS fibers in the bone marrow without blocking the anticancer efficacy of cisplatin, and it results in the restoration of blood cells and amelioration of sensory neuropathy. Therefore, these results suggest that NPY can be used as a potentially effective agent to improve bone marrow dysfunction during cisplatin-based cancer therapy.

• BMB Reports
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• v.50 no.3
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• pp.138-143
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• 2017

Ovariectomy-induced bone loss is related to an increased deposition of osteoclasts on bone surfaces. We reported that the 36-amino-acid-long neuropeptide Y (NPY) could mobilize hematopoietic stem/progenitor cells (HSPCs) from the bone marrow to the peripheral blood by regulating HSPC maintenance factors and that mobilization of HSPCs ameliorated low bone density in an ovariectomy-induced osteoporosis mouse model by reducing the number of osteoclasts. Here, we demonstrated that new NPY peptides, recombined from the cleavage of the full-length NPY, showed better functionality for HSPC mobilization than the full-length peptide. These recombinant peptides mediated HSPC mobilization with greater efficiency by decreasing HSPC maintenance factors. Furthermore, treatment with these peptides reduced the number of osteoclasts and relieved ovariectomy-induced bone loss in mice more effectively than treatment with full-length NPY. Therefore, these results suggest that peptides recombined from full-length NPY can be used to treat osteoporosis.