• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.413-421
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• 2000

The purpose of this study was to observe the effects of pregnancy on the experimental tooth movement and alveolar bone turnover process of Sprague-Dawley female rat. Sixty rats were divided into pregnant-tooth movement group(P-Tm), normal-tooth movement group(N-Tm) and normal group(N). Maxillary first molar appliances were inserted bilaterally and activated to 40grams. To measure the amount of tooth movement, x-ray was taken 2 times after appliance insertion and before sacrifice. Animals were sacrificed at 1,3,7,14 days(N=5). Just after sacrifice, alveolar bones were collected and frozen immediately for biochemical analysis. Tooth movement was assessed cephalometrically and tartrate-resistant acid(TRAP) and alkaline phosphatase (ALP) activities were measured in extracts of paradental alveolar bone. The results were as follows: 1. The amount of tooth movement in P-Tm group was greater than that of N-Tm group(p<0.01). 2. Alveolar bone ALP of normal tooth movement group was not significantly different from the control, TRAP was significantly different from the control(p<0.01). In normal tooth movement group, alveolar bone ALP was increased gradually and peak(day 7) fell off significantly at day 14(p<0.05). The Peak of alveolar bone TRAP(day 7) fell off slightly, sustained day 14(p<0.01). 3. Alveolar bone ALP and TRAP of pregnant tooth movement group were not significantly different from that of normal tooth movement group. In pregnant tooth movement group, alveolar bone ALP was increased at day 3(p<0.01) and fell off significantly at day 7-14, alveolar bone TRAP were increased at day 3 and sustained day 14. 4. The peak of alveolar bone phosphatases in pregnant tooth movement group(day3) preceded the peak in normal tooth movement group(day7) (p<0.01). According to the above results, we suggested that bone resorption activity was increased in alveolar bone of pregnant rat, and the degree of tooth movement in pregnancy may be greater than that of normal group because of high bone turnover of alveolar bone in pregnant rat.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1415-1423
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• 2007

Carbon tetrachloride ($CCl_4$)-induced liver injury depends on a toxic agent that has to be metabolized by the liver NAPDH-cytochrome P450 enzyme system to a highly reactive intermediate. Alternations in the activity of cytochrome P450 enzymes affect the susceptibility to hepatic injury from $CCl_4$. In this study, we evaluated the potential protective activity of the traditional Korean medicinal herb, Corni fructus (CF), against an experimental model of hepatotoxicity induced by $CCl_4$. The CF exhibited a hepatoprotective activity against $CCl_4-induced$ liver damage in Sprague-Dawley (SD) rats, as measured by GOT, GPT, ALP and histological observation. The CF also showed significant decrease of malodialdehyde (MDA) and increase of glutathion (GSH), catalase activity in rat liver homogenate. In addition, the expression of CYP2E1, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, was significantly decreased in the liver of CF treated SD rats. But $CCl_4$ and CF has no significant effect on 1A1 and 3A1 isoform of cytochrome P450. Based on these findings, it is suggested that hepatoprotective effects of CF possibly related to antioxidative effects and regulation of CYP2E1 expression.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.333-340
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• 2011

Purpose: The aim of this study was to study the effect of hydroxyapatite (HA) coating crystallinity on the proliferation and differentiation of human osteosarcoma cells. Materials and methods: Surface roughness of the titanium disks increased by anodizing treatment and then HA was coated using ion beam-assisted deposition (IBAD). HA coating was crystallized by heat-treated at different temperature ($100^{\circ}C$, $300^{\circ}C$, $500^{\circ}C$, $800^{\circ}C$). According to the temperature, disks were divided into four groups (HA100, HA300, HA500, HA800). With the temperature, crystallinity of the HA coating was different. Anodized disks were used as control group. The physical properties of the disk surface were evaluated by surface roughness tests, XRD tests and SEM. The effect of the crystallinity of HA coating on HOS cells was studied in proliferation and differentiation. HOS cells were cultured on the disks and evaluated after 1, 3, 5, and 7 days. Growth and differentiation kinetics were subsequently investigated by evaluating cell proliferation and alkaline phosphatase activity. Results: Regardless of the heat-treated temperature, there is no difference on the surface roughness. Crystallinity of the HA was appeared in the groups of HA500, HA800. HOS cells proliferation, ALP activity were higher in HA500 and HA800 group than HA100 and HA300. Conclusion: Within the results of this limited study, heat treatment at $500^{\circ}C$ of HA coating produced by IBAD has shown greater effect on proliferation and differentiation of HOS cells. It is considered that further in vivo study will be necessary.

• Journal of Life Science
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• v.22 no.4
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• pp.456-465
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• 2012

Heterodimeric recombinant human bone morphogenetic proteins (rhBMPs) are powerful tools for bone tissue engineering. However, BMPs have several important limitations in their application to bone regeneration. BMPs have a short half-life and must be used in high concentrations, which may be cost-inefficient. To overcome these problems, we established a stable cell line that expressed the fusion protein comprised of recombinant human BMP2/7 heterodimer protein and PTD (rhBMP2/7-PTD). This stable cell line enabled high process yields by continuously expressing rhBMP2/7-PTD products at high levels throughout cultivation. This synthesized BMP7 was fused to a BMP2 protein with four glycine residues (to allow free bond rotation of the domains) and PTD. To demonstrate that the rhBMP2/7-PTD protein that was secreted from an rhBMP2/7-PTD-expressing stable cell line exhibited biological activity consistent with its role as an osteogenic differentiation induction growth factor, we evaluated BMP-induced ALP activity. Our results suggest that this cell line may be a powerful and efficient tool for applications such as bone tissue regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.341-345
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• 2010

Introduction: Skeletal homeostasis is normally maintained by the stability between bone formation by osteoblasts and bone resorption by osteoclasts. However, the correlation between the inflammatory reaction and osteoblastic differentiation of cultured osteoprogenitor cells has not been fully investigated. This study examined the effects of inflammatory cytokines on the osteoblastic differentiation of cultured human periosteal-derived cells. Materials and Methods: Periosteal-derived cells were obtained from the mandibular periosteum and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured in an osteogenic induction Dulbecco's modified Eagle's medium (DMEM) medium containing dexamethasone, ascorbic acid, and $\beta$-glycerophosphate. In this culture medium, tumor necrosis factor (TNF)-$\alpha$ with different concentrations (0.1, 1, and 10 ng/mL) or interleukin (IL)-$1{\beta}$ with different concentrations (0.01, 0.1, and 1 ng/mL) were added. Results: Both TNF-$\alpha$ and IL-$1{\beta}$ stimulated alkaline phosphatase (ALP) expression in the periosteal-derived cells. TNF-$\alpha$ and IL-$1{\beta}$ increased the level of ALP expression in a dose-dependent manner. Both TNF-$\alpha$ and IL-$1{\beta}$ also increased the level of alizarin red S staining in a dose-dependent manner during osteoblastic differentiation of cultured human periosteal-derived cells. Conclusion: These results suggest that inflammatory cytokines TNF-$\alpha$ and IL-$1{\beta}$ can stimulate the osteoblastic activity of cultured human periosteal-derived cells.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.190-197
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• 2017

BACKGROUND/OBJECTIVES: Gallus gallus domesticus (GD) is a natural mutant breed of chicken in Korea with an atypical characterization of melanin in its tissue. This study investigated the effects of melanin extracts of GD on osteoblast differentiation and inhibition of osteoclast formation. MATERIALS/METHODS: The effects of the melanin extract of GD on human osteoblast MG-63 cell differentiation were examined by evaluating cell viability, osteoblast differentiation, and expression of osteoblast-specific transcription factors such as bone morphogenetic protein 2 (BMP-2), small mothers against decapentaplegic homologs 5 (SMAD5), runt-related transcription factor 2 (RUNX2), osteocalcin and type 1 collagen (COL-1) by reverse transcription-polymerase chain reaction and western blotting analysis. We investigated the inhibitory effect of melanin on the osteoclasts formation through tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains in Raw 264.7 cell. RESULTS: The melanin extract of GD was not cytotoxic to MG-63 cells at concentrations of $50-250{\mu}g/mL$. Alkaline phosphatase (ALP) activity and bone mineralization of melanin extract-treated cells increased in a dose-dependent manner from 50 to $250{\mu}g/mL$ and were 149% and 129% at $250{\mu}g/mL$ concentration, respectively (P < 0.05). The levels of BMP-2, osteocalcin, and COL-1 gene expression were significantly upregulated by 1.72-, 4.44-, and 2.12-fold in melanin-treated cells than in the control cells (P < 0.05). The levels of RUNX2 and SMAD5 proteins were higher in melanin-treated cells than in control vehicle-treated cells. The melanin extract attenuated the formation of receptor activator of nuclear factor kappa-B ligand-induced TRAP-positive multinucleated RAW 264.7 cells by 22%, and was 77% cytotoxic to RAW 264.7 macrophages at a concentration of $500{\mu}g/mL$. CONCLUSIONS: This study provides evidence that the melanin extract promoted osteoblast differentiation by activating BMP/SMADs/RUNX2 signaling and regulating transcription of osteogenic genes such as ALP, type I collagen, and osteocalcin. These results suggest that the effective osteoblastic differentiation induced by melanin extract from GD makes it potentially useful in maintaining bone health.

• Journal of Nutrition and Health
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• v.45 no.2
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• pp.121-126
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• 2012

This study evaluated the effect of fish oil rich in n-3 fatty acids on bone characteristics in Sprague-Dawley rats. Weanling male rats were randomized to receive either a diet containing high fish oil (FO), fish oil blended with corn oil (FICO), or soy oil rich in n-6 fatty acids (SO) for 4 weeks. All diets provided 70 g/kg fat based on the AIN-93G diet. Growth and biomarkers of bone metabolism were analyzed, and femur bone characteristics were measured by dual-energy X-ray absorptiometry. After the dietary treatment, no significant differences among the diet groups were observed for serum concentrations of Ca, parathyroid hormone, calcitonin, or osteocalcin. Alkaline phosphatase activity was significantly greater in FO-fed rats compared to that in the FICO and SO groups, whereas no difference in deoxypyridinoline values was observed, supporting the positive effect of a FO diet on bone formation. These results were accompanied by a significant increase in femur bone mineral density (BMD) in FO-fed rats. These findings suggest that providing fish oil rich in n-3 fatty acids correlates with higher alkaline phosphatase activity and BMD values, favoring bone formation in growing rats.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.41-49
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• 2014

This study was conducted to investigate the effects of cadmium (Cd) exposure on biochemical factors in the hemolymph and hepatopancreas of the abalone, Haliotis discus hannai. The abalone were exposed to 0, 5, 10, 20 and 40 ${\mu}g/L$ Cd for 4 weeks. The phenoloxidase (PO) activity was decreased in hemolymph of abalone exposed to 40 Cd ${\mu}g/L$ for 4 weeks compared to the control (P < 0.05). The hemolymph enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were markedly elevated in 40 Cd ${\mu}g/L$ after 4 weeks. The hemolymph calcium concentrations were significantly decreased in 20 and 40 Cd ${\mu}g/L$ for 4 weeks. Hepatopancreas superoxide dismutase (SOD) and catalase (CAT) activities were significantly increased by Cd. SOD was increased in both 20 and 40 Cd ${\mu}g/L$ and CAT, in 40 Cd ${\mu}g/L$ after 2 weeks (P < 0.05). These results suggested that the abalone SOD and CAT including PO may serve as a protective mechanism against oxidative stress by Cd. We conclude that a Cd concentration, 40 ${\mu}g/L$ in water may curtail hemolymph homeostasis and anti-oxidative reactions in abalone hepatopancreas. From these results, these biochemical factors may represent a convenient method of monitoring heavy metal pollution in coastal areas.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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• pp.307-326
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• 2004

Statement of problem. The long-term success of implants is the development of a stable direct connection between bone and implant surface, which must be structural and functional. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. Among them, altering the surface properties can modify cellular responses such as cell adhesion, cell motility and bone deposition. Purpose. This study was to evaluate the cellular behaviors on the surface-modified titanium by morphological observation, cellular proliferation and differentiation. Material and methods. Specimens were divided into five groups, depending on their surface treatment: electropolishing(EP) anoclizing(AN), machining(MA), blasting with hydroxyapatite particle(RBM) and electrical discharge machining(EDM). Physicochemical properties and microstructures of the specimens were examined and the responses of osteoblast-like cells were investigated. The microtopography of specimens was observed by scanning electron microscopy(SEM). Surface roughness was measured by a three-dimensional roughness measuring system. The microstructure was analyzed by X-ray diffractometer(XRD) and scanning auger electron microscopy(AES). To evaluate cellular responses to modified titanium surfaces, osteoblasts isolated from neonatal rat were cultured. The cellular morphology and total protein amounts of osteoblast-like cell were taken as the marker for cellular proliferation, while the expression of alkaline phosphatase was used as the early differentiation marker for osteoblast. In addition, the type I collagen production was determined to be a reliable indicator of bone matrix synthesis. Results. 1. Each prepared specimen showed specific microtopography at SEM examination. The RBM group had a rough and irregular pattern with reticulated appearance. The EDM-treated surface had evident cracks and was heterogeneous consisting of broad sheet or plate with smooth edges and clusters of small grains, deep pores or craters. 2. Surface roughness values were, from the lowest to the highest, electropolished group, anodized group, machined group, RBM group and EDM group. 3. All groups showed amorphous structures. Especially anodized group was found to have increased surface oxide thickness and EDM group had titaniumcarbide(TiC) structure. 4. Cells on electropolished, anodized and machined surfaces developed flattened cell shape and cells on RBM appeared spherical and EDM showed both. After 14 days, the cells cultured from all groups were formed to be confluent and exhibited multilayer proliferation, often overlapped or stratified. 5. Total protein amounts were formed to be quite similar among all the group at 48 hours. At 14 days, the electropolished group and the anodized group induced more total protein amount than the RBM group(P<.05). 6. There was no significant difference among five groups for alkaline phosphatase(ALP) activity at 48 hours. The AN group showed significantly higher ALP activity than any other groups at 14 days(P<.05). 7. All the groups showed similar collagen synthesis except the EDM group. The amount of collagen on the electropolished and anodized surfaces were higher than that on the EDM surface(P<.05).

• YAKHAK HOEJI
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• v.40 no.6
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• pp.705-712
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• 1996

We have previously shown that determination of glucose uptake using ${\alpha}$-methylglucose(${\alpha}$-MG) is very sensitive and rapid parameter for the assessment of loss of cellular fu nction in renal cell line($LLC-PK_1$). The present study was designed to elucidate the mechanism of inhibition of ${\alpha}$-MG uptake and the intracellular site of toxic action of cisplatin(CIS). $LLC-PK_1$ cells were exposed to various concentrations(5 ${\mu}$M-l00 ${\mu}$M) of CIS for 5 hrs or 24 hrs and ${\alpha}$-MG uptake was determined. Mitochondrial function was evaluated by measuring intracellular ATP content and MTT reduction. The activities of marker enzymes for the basolateral membrane(Na$^+$-K$^+$ ATPase) and brush border membrane (alkaline phosphatase: ALP) were also measured. CIS treatment significantly inhibited the ${\alpha}$-MG uptake in a time- and dose-dependent manner above 25 ${\mu}$M for 5 hrs. Intracellular ATP content and MTT reduction were affected by 24 hr-treatment of 50 ${\mu}$M CIS. The activities of Na$^+$-K$^+$ ATPase and ALP were significantly decreased at 10 ${\mu}$M and 5 ${\mu}$M of CIS for 24 hrs, respectively. The incubation with CIS for 5 hrs had no effects on the intracellular ATP content, MTT reduction and the activities of marker enzymes up to 100 ${\mu}$M. These results partly indicate that inhibition of ${\alpha}$-MG uptake by CIS may not be attributed to the disturbance of mitochondrial function or inhibition of the activity of Na$^+$-K$^+$ ATPase and can be resulted from direct effect of CIS on the Na$^+$/glucose cotransporter in brush border membrane. This study shows that additional mechanistic information, indicating the intracellular site of nephrotoxic action, can be gained by coupling the ${\alpha}$-MG uptake and ATP content or the activity of Na$^+$-K$^+$ ATPase.