• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.163-180
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• 2001

The aim of this study was to evaluate the effects of chitosan coating on the attachment, proliferation, functional and morphological change of periodontal ligament cells. Primary human periodontal ligament cells were cultured in dulbecco's modified Eagle's medium with 10% fetal bovine serum and 1% antibiotics. In experimental group, cells of 4th to 7th passage were inoculated in the multiwell plates coated with chitosan in concentration of 0.22, 0.2, and $2mg/m{\ell}$. Cell counting and MTT assay were done after 0.5, 1.5, 3, 6 and 24 hours of incubation to evaluate the cell attachment, and then after 2 and 7 days of culture to evaluate the cell proliferation. The alkaline phosphatase activity was measured after 4 and 7 days of culture and the ability to produce mineralized modules was evaluated after 21 days of culture. The results were as follows : 1. The morphology of periodontal ligament cells on the chitosan coating was round or spheric. Round cells were aggregated after 6 hours of culture. Aggregated cells on the chitosan coated surface showed nodule-like appearance after 24 hours of culture and not achieved confluency at 7 days. 2. During early period of culture, the attachment of periodontal ligament cells were inhibited by chitosan coating. Inhibition of cell attachment tended to increase with the concentration of chitosan. 3. At the chitosan concentration of 0.02 and $0.2mg/m{\ell}$, periodontal ligament cells were more rapidly proliferated at 7 days, compared to the control group. At the concentration of $2mg/m{\ell}$, the proliferation of periodontal ligament cells was inhibitied(p<0.01). 4. Alkaline phosphatase activity of periodontal ligament cells was increased in chitosan coated group, especially at the concentration of $0.02mg/m{\ell}$after 4 days of culture.5. Periodontal ligament cells produced mineralized nodules on chitosan coated wells without the addition of mineralized nodule forming materials (ascorbic acid, ${\beta}-glycerophosphat$, dexamethasone). With the addition of mineralized nodule forming materials, periodontal ligament cells produced more mineralized nodules at the concentration of $0.02mg/m{\ell}$, compared to the control. In summary, the attachment, proliferation, cell activity, and alkaline phosphatase activity of periodontal ligament cells depended on the concentration of coated chitosan. Chitosan stimulated mineralized nodule formation by periodontal ligament cells. At the appropriate concentration($0.02mg/m{\ell}$), chitosan could increase alkaline phosphatase activity and stimulate the formation of mineralized nodule by periodontal ligament cells. These results suggest that chitosan can be used as an adjunct for bone graft material, and the matrix of tissue engineering for periodontal regeneration, especially bone regeneration.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.109-122
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• 2001

Gingival fibroblasts(GF) and periodontal ligament fibroblasts(PDLF) are the major cellular components of periodontal soft connective tissues, but the precise molecular biological differences between these cells are not yet known. In the present study, we investigated the expression of S100A4, S100A2 calcium-binding protein and osteoblast-specific factor 2(OSF-2, Periostin) mRNA in GF and PDLF in vitro through the process of reverse transcription-polymerase chain reaction(RT-PCR) and Northern blot analysis in each. Human GF and PDLF were isolated from the gingival connective tissue and the middle third of freshly extracted healthy third molars. They were cultured in Dulbecco's Modified Eagle Medium(DMEM) containing 10% fetal bovine serum and cells in the third passage were used in the experiments. After extracting total RNA from cultured cells, RT-PCR and Northern analysis were performed using S100A4-, S100A2- and Periostin-specific oligonucleotide primers and subcloned cDNA probes in each. In PT-PCR and Northern analysis, the expression of S100A4 and Periostin mRNA in GF was slightly detectable. Interestingly, the expression of S100A4 and periostin mRNA in PDLF was much higher than that in GF. On the other hand, S100A2 mPNA was highly expressed in both GF and PDLF. Since there was a marked difference of S100A4 and Periostin expression between GF and PDLF in vitro, these data suggest that S100A4 and periostin could be used as a useful marker for distinguishing cultured gingival fibroblasts and periodontal ligament cells.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.333-344
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• 2004

The enamel matrix derivative (EMD) has been recently used in the periodontal regenerative techniques. The present study was established to investigate the influence of EMD on human periodontal ligament cells using expression of mRNA of periodontal ligament specific gene (PDLs)17, PDLs22, type I collagen when EMD applied to periodontal ligament cells. Periodontal ligament cells were obtained from a healthy periodontium and cultured in Dulbecco's modified Eagle's medium (DMEM) plus 10% fetal bovine serum and ${\beta}-glycerophosphate$ with ascorbic acid. Test groups were two; One adds EMD in culture media and another added EMD and Dexamethasone (DEX) in culture media. Positive control group added DEX in culture media, and negative control group adds niether of EMD nor DEX. $Emdogain^{(R)}$ (Biora, Sweden, 30 mg/ml) was diluted by 75 ${\mu}g/ml$ concentration to culture media. For reverse transcription-polymerase chain reaction (RT-PCR), total RNA isolated on days 0, 7, 14 and 21. mRNA of PDLs17 was expressed on days 14 and 21 in EMD or DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group, the other side, expressed on days 21 in negative control group. mRNA of PDLs22 expressed on days 7, 14 and 21 in EMD group, and expressed on days 14 and 21 in DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group. Negative control group expressed on days 14 and 21. Type I collagen was expressed on all days and all groups. These results indicate that EMD promotes differentiation of periodontal ligament cells, and this is considered to offer basis that can apply EMD to periodontal tissue regeneration technique.

• International Journal of Oral Biology
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• v.37 no.2
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• pp.43-50
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• 2012

The use of high throughput screening (HTS) in drug development is principally for the selection new drug candidates or screening of chemical toxicants. This system minimizes the experimental environment and allows for the screening of candidates at the same time. Umbilical cord-derived stem cells have some of the characteristics of fetal stem cell and have several advantages such as the ease with which they can be obtained and lack of ethical issues. To establish a HTS system, optimized conditions that mimic typical cell culture conditions in a minimal space such as 96 well plates are needed for stem cell growth. We have thus established a novel HTS system using human umbilical cord derived-mesenchymal stem cells (hUC-MSCs). To determine the optimal cell number, hUC-MSCs were serially diluted and seeded at 750, 500, 200 and 100 cells per well on 96 well plates. The maintenance efficiencies of these dilutions were compared for 3, 7, 9, and 14 days. The fetal bovine serum (FBS) concentration (20, 10, 5 and 1%) and the cell numbers (750, 500 and 200 cells/well) were compared for 3, 5 and 7 days. In addition, we evaluated the optimal conditions for cell cycle block. These four independent optimization experiments were conducted using an MTT assay. In the results, the optimal conditions for a HTS system using hUC-MSCs were determined to be 300 cell/well cultured for 8 days with 1 or 5% FBS. In addition, we demonstrated that the optimal conditions for a cell cycle block in this culture system are 48 hours in the absence of FBS. In addition, we selected four types of novel small molecule candidates using our HTS system which demonstrates the feasibility if using hUC-MSCs for this type of screen. Moreover, the four candidate compounds can be tested for stem cell research application.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.193-213
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• 2003

The purpose of this study is to evaluate the phenomenon of attachment and spreading of the cultured rat　calvarial cell inoculated on their surface of different kinds of biodegradable membrane which had been used on tissue regeneration on periodontal defects by using scanning electron microscope. In this experiment 30 Sprague-Dawley male rats (mean BW 150gm) were used to harvest abundant number of cell in the short period. The rats were sacrificed by decapitatioan to obtain the calvaria for bone cell culture. Calvarial cells were cultured with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. Biodegradable barrier membrane were collected with collagen type, and were divided into 3 different kind of surface such as scattered, polarized and fine-net type as their surface texture. Microcover plate which usually used for cell culture was used as control for smooth surface. All the membrane were seeded with cultured calvarial cell on their surface. The number of cell inoculated on the membrane were $1{\times}10^6$ Cells/ml. After the culture as designed time, all the membrane were washed with 0.1 M Phosphate Buffered saline and fuxed with 2.5% Glutaraldehyde. And all specimen were treated with $OsO_4$, and Tannic acid before drying the cell for coating the cell with gold. Scanning Electron Microscope was used to observation. The following results were obtained. I. During the whole period of experiment, the phenomenon of cell attachment and spreading were revealed similar pattern to compare with smooth surface culture plate and ordinary culture dish. 2. The shape of cell attachment and spreading on the surface of barrier membrane were observed no remarked difference pattern between smooth surface culture plate and ordinary culture dish. 3. The cytoplasmic process of cultured calvaria cell extent to the deep portion of barrier membrane like as their own proper shape. 4. There were no remarkable relationships between the degree of cultured cell spreading and surface structure of barrier membrane. 5. Slight starified layer of cultured calvaria cell were observed on the scattered type of resorbable membrane, Conclusively, this study thus suggest that cultured bone cell inoculated onto the biodegradable barrier membrane may have an important role of carrier for many cell which could be used as new tissue regeneration, and those tissue engeering technique may become an new method in the approach to the repair of bone defects.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.277-288
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• 2003

It has been suggested that increased number and activity of phagocytes in periodontitis lesion results in a high degree of reactive oxygen species (ROS) such as superoxide anion, hydrogen peroxide, nitric oxide and peroxynitrite. There are few reports on the relationship between ROS and MMPs expressions in gingival fibroblast. We studied to elucidate whether and how ROS, especially nitric oxide affects the MMP expression. Human gingival fibroblasts and HTl080 cells (human fibrosarcoma sell line as reference) were grown in DMEM supplemented with 10 mM HEPES, 50 mg/L gentamicin, and 10% heat inactivated fetal bovine serum with addition of various reactive oxygen species (ROS). Culture media conditioned by cells were examined by gelatin zymography. HT1080 cells expressed proMMP-2 and proMMP-9, but human gingival fibroblasts (HGF) produced only proMMP-2. Hydrogen peroxide upregulated MMP-9 expression in HT1080 cells, whereas in human gingival fibroblast SNP treatment showed marked increase in MMP-2 level compared to other ROS. These results suggest that the effects of ROS on MMPs expressions are cell-type specific. RT-PCR for MMP-2 and TIMP-2 m-RNA were performed using total RNA from cultured cells under the influence various kinase inhibitors. In HT1080 cells, treatment with FPTI III (Ras processing inhibitor) and LY294002 (PI3-kinase inhibitor) resulted in inhibition of MMP-2 and MMP-9 expressions, suggesting that Ras/P13-kinase pathway is important for MMPs expression in HT1080 cells. In gingival fibroblasts, treatment with FPTI III and PDTC (NF-kB inhibitor) showed marked decrease in MMP-2 regardless of the of SNP , suggesting that Ras/NF-kB could be the key pathway for NO-induced MMP-2 expression in gingival fibroblasts. This study showed that ROS, especially nitric oxide, could be the critical mediator of periodontal disease progression through control of MMP-2 expression in gingival fibroblasts possibly via Ras/NF-kB pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.19-24
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• 2009

This study was performed to investigate the antioxidative effects such as the inhibition of malondialdehyde (MDA) and bovine serum albumin (BSA) conjugation reaction, inhibition of $Fe^{2+}$-induced lipid peroxidation and the scavenging effect on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical, as well as antimutagenic capacities as Ames test in ethanol extracts of Agaricus bisporus. Agaricus bisporus ethanol extracts inhibited $Fe^{2+}$-induced lipid peroxidation and scavenged DPPH radical. The $IC_{50}$ of Agaricus bisporus ethanol extracts were 78.63 mg/assay for inhibition of MDA with BSA conjugation reaction, 4.06 mg/ assay for inhibition of $Fe^{2+}$-induced lipid peroxidation and 1.08 mg/assay for scavenging effect on DPPH radical. So, among the methods used in this study, the most effective antioxidative capacity in ethanol extracts of Agaricus bisporus was the scavenging effect on DPPH radical. The indirect and direct antimutagenic effects of ethanol extracts of Agaricus bisporus were examined by Ames test using Salmonella Typhimurium TA98 and TA100. The inhibitory effects on direct mutagenicity mediated by sodium azide in Salmonella Typhimurium TA100 and 2-nitrofluorene in Salmonella Typhimurium TA98 were 100%. The inhibition rates on indirect mutagenicity mediated by 2-anthramine were 86.09% in the Salmonella Typhimurium TA98 and 81.93% in the Salmonella Typhimurium TA100. The ethanol extracts of Agaricus bisporus showed considerable antioxidative activity and strong antimutagenic capacity.

• Herbal Formula Science
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• v.14 no.2
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• pp.76-85
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• 2006

Objectives : We Investigated the effect of Dioscoreae Rhizoma(山藥) on the change of the corticosterone and the rectal temperature(直腸溫渡) of the mice induced by starvation stress(創戰 스트레스). Methods : After administration of Dioscoreae Rhizoma (0.25g/kg, 0.5g, 1.0g/kg, 3g/kg) three times, mice were starved. The corticosterone and rectal temperature were measured after 36.5 hours starvation stress. Results : The plasma cortiosterone levels in the S-2, S-3 and S-4 group were decreased significantly comparing with the control group (P<0.01) after 36.5 hours starvation stress. and rectal temperature was decreased in the control goup comparing with the normal group, but there is no significant change in the Dioscoreae Rhizoma treated group. Conclusion : it might be recognized that Dioscoreae Rhizoma has preventive-effect against starvation stress and also it might be needed further study in various viewpoints. Objectives : This study was disegned to elucidate the short term effect of Rossa rugosae Radix on proliferation. differentiation and maturation of 3T3-L1 Preadipocyte. Methods: 3T3-L1 preadipocytes obtained from Korean Cell Line Bank were cultured in a D ulbecco’ s modified eagle medium(MEM) culture solution containing 10% fetal bovine serum(FBS) and various concentrations of aqueous extract of Rossa rugosae Radix.. The short term effect of the extract of Rossa rugosae Radix on proliferation. differentiation and maturation of 3T3-L1 preadipocytes were investigate after treatment for 24 hours by measuring MTT. Oil Red 0 and latate dehydrogenase activity.. Results: The Rossa rugosae Radix extract inhibited significantly the proliferation of 3T3-L1 preadipocytes and tended to increase latate dehydrogenase activity in the media of differentiated 3T3-L1 preadipocytes & matured 3T3-L1 preadipocytes. the extract also inhibit the lipid accumulation of differentiated 3T3-L1 preadipocytes & matuered 3T3-L1 preadipocytes. Conclusions: These results demonstrated that the Rossa rugosae Radjx extract inhibited the proliferation. differentiation and maturation of 3T3-L1 preadipocytes. suggesting that Rossa rugosae Radix has anti-obesity effect: however further in vivo study is needed to demonstrate its pharmacological effects.

• Korean journal of food and cookery science
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• v.27 no.3
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• pp.29-37
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• 2011

Protease activity of fig (Ficus carica L.), cultivated in Korea was estimated. In particular, the proteolytic effect on myofibrilar protein was studied. A crude protease extract of fig was prepared in two ways; fig was homogenized in buffer followed by centrifugation, and the supernatant was precipitated by saturated ammonium sulfate followed by dialysis. The former method resulted in 41.15 mM/g fig protease activity, whereas the latter method resulted in 17.65 mM/g fig protease activity. The crude fig protease extract showed high specificity for casein as a substrate followed by egg white, bovine serum albumin, myofibrilar protein, collagen, and elastin. The extract had stable proteolytic activity in a pH range of 6.5~9.0 (optimal at pH 7-8) but lost activity, at pH 2-3. Proteolytic activity for myofibrilar protein was sensitive to pH. The proteolytic activity of the fig extract was steady up to $60^{\circ}C$ but declined at higher temperature. It also began to lose stability in salt concentrations >0.7 M NaCl. Fig has been used as a meat tenderizer for cooking, and these results support the tenderizing effectiveness of fig, particularly for Korean style meat marinating.

• Development and Reproduction
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• v.2 no.1
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• pp.1-8
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• 1998

In mammalian ovary, major portion(>99%) of ovarian follicles undergo atresia. Recent studies have shown that this phenomenon is mediated via GC apoptosis. Ceramide, a product of sphingomyelin hydrolysis, has been proposed as a novel lipid second messenger with specific roles in mediating antiproliferative responses including apoptosis and cell cycle arrest. In the present study, we have examined the effect of ceramide on apoptotic cell death of GC in vitro. GCs were harvested by squeezing the antral follicles from the immature mice (3-4 weeks) and cultured in MEM medium with 10% fetal bovine serum. The cells were treated with various concentrations of ceramide (0 to 50 \mu M)and cultured up to 24 h.Cell death was determined by MTT cell viability assay and apoptosis was examined by acridine orange staining, in situ 3'-end labeling(TUNEL), and flow cytometry. Ceramid treatment induced apoptotic cell death of GC in a time- and a dose-dependent manner. Results of flow cytometric analysis showed that creamide-induced cell death was mostly confined to the $G_{0}$/$G_{1}$ cells. these results provide an evidence for ceramide as a lipid second messenger of apoptosis in mouse GC.