• 한국미생물·생명공학회지
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• 제39권4호
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• pp.337-344
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• 2011

이전 연구에서, bacteriophage ${\Phi}FC1$이 Enterococcus faecalis KBL703에서 UV induction을 통해 분리 동정되었으며, ${\Phi}FC1$은 phage attachment site인 attP와 bacterial attachment site인 attB 사이에서 site-specific integration을 촉매하는 integrase를 가지고 있다는 것을 밝혀냈으며 이를 MJ1이라 명명하였다. 이 연구에서는 이를 바탕으로 MJ1에 의한 site-specific integration의 효율을 Escherichia coli와 NIH3T3 cell에서 확인 하기 위해 attP, attB, MJ1을 각각의 벡터에 삽입하였다. MJ1 인테그라제에 의한 재조합을 수행하기 위해서 기질 벡터 pABLP를 $DH5{\alpha}$에 형질전환시킨 후, LB 배지에서 $37^{\circ}C$ 1시간 배양한 후 암피실린(ampicillin)과 테트라싸이클린(tetracycline) 항생제 플레이트로 pGMJ1과 pABLP 같이 가지고 있는 colony 들을 선별하여, LacZ 유전자가 불활성화 된 흰색 콜로니 개수를 세고 통계를 낸 결과 integration의 frequency가 99% 이상인 것으로 나타났다. 또한, 실제로 재조합이 일어났는 지를 확인하기 위해서 콜로니 PCR을 수행하여 재조합의 산물인 attL 150 bp을 확인하였다. PCR 산물은 염기서열분석을 통해 정확한 site-specific integration이 일어났음을 확인하였다. MJ1에 의한 integration을 보이기 위해 attP와 attB를 가지고 있는 vector를 MJ1 expression vector와 함께 NIH3T3 cell에 cotransfection 했으며 GFP를 reporter로 사용해 그 activity를 관찰하였다. NIH3T3 cell에서 GFP의 발현을 형광 현미경을 통해 알아본 결과, MJ1에 의한 sitespecific integration이 다른 accessory protein의 도움 없이 일어난다는 것을 볼 수 있었다. 마찬가지 방법으로, attR과 attL 간의 excision을 GFP로 알아본 결과, GFP는 발현하지 않았으며, 이는 MJ1에 의한 excision이 일어나지 않았음을 보여주었다. 이와 같은 결과로 볼 때, MJ1의 host만이 아니라 넓은 범위안에서도 integration을 수행할 수 있다는 것을 보여주었다. 따라서 MJ1을 이용한 site-specific integration system의 개발은 gene therapy를 위한 gene delivery system의 구축에 있어서 좋은 시작이 될 수 있다.

• Clinical and Experimental Reproductive Medicine
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• 제47권2호
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• pp.114-121
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• 2020

Objective: Despite extensive research on implantation failure, little is known about the molecular mechanisms underlying the crosstalk between the embryo and the maternal endometrium, which is critical for successful pregnancy. Profilin 1 (PFN1), which is expressed both in the embryo and in the endometrial epithelium, acts as a potent regulator of actin polymerization and the cytoskeletal network. In this study, we identified the specific role of endometrial PFN1 during embryo implantation. Methods: Morphological alterations depending on the status of PFN1 expression were assessed in PFN1-depleted or control cells grown on Matrigel-coated cover glass. Day-5 mouse embryos were cocultured with Ishikawa cells. Comparisons of the rates of F-actin formation and embryo attachment were performed by measuring the stability of the attached embryo onto PFN1-depleted or control cells. Results: Depletion of PFN1 in endometrial epithelial cells induced a significant reduction in cell-cell adhesion displaying less formation of colonies and a more circular cell shape. Mouse embryos co-cultured with PFN1-depleted cells failed to form actin cytoskeletal networks, whereas more F-actin formation in the direction of surrounding PFN1-intact endometrial epithelial cells was detected. Furthermore, significantly lower embryo attachment stability was observed in PFN1-depleted cells than in control cells. This may have been due to reduced endometrial receptivity caused by impaired actin cytoskeletal networks associated with PFN1 deficiency. Conclusion: These observations definitively demonstrate an important role of PFN1 in mediating cell-cell adhesion during the initial stage of embryo implantation and suggest a potential therapeutic target or novel biomarker for patients suffering from implantation failure.

• 한국정밀공학회지
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• 제15권8호
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• pp.109-115
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• 1998

This paper describes the development of a 6-component load cell with plate beams which may be used to measure forces Fx, Fy, Fz and moments Mx, My, Mz simultaneously in industry. We have analyzed the bending strains on the surface of the beams under forces or moments by using Finite Element Method and designed the sensing elements of 6-component load cell. We have also determined the attachment location of strain gages of each load cell and fabricated 6-component load cell. To evaluate the rated strain and interference error of each load cell, we have carried out characteristic test of 6-component load cell.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.77-96
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• 1993

정상치아와 이환치아 및 구연산에 의하여 탈회한 치근면에대한 치주인대세포의 부착상태를 비교관찰 하기 위하여 정상치아와 이환치아를 취하여 정상군, 이환치근의 치근면활택술군 및 구연산처리군으로 분류하고 시험관적 실험을 통하여 관찰하였다. 세포부착실험전 각 군의 치근면의 형태를 주사전자현미경을 이용하여 관찰하였으며, 사람의 정상소구치에서부터 얻어진 치주인대세포를 배야하여 각 군의 절편을 함유한 조직배양기에 ml당 $4.5{\times}\;10^4$개의 세포를 가진 배양액 1ml씩을 넣고 동일조건하에서 30분, 1시간, 2시간, 6시간, 12시간 및 24시간 동안 배양한 후 세포의 부착이 일어난 후 상태를 주사전자현미경을 이용하여 관찰하였고, 세포증식정도를 알아보기 위하여 각 절편에 $5{\times}10^4$개의 세포가 함유된 배양액 1ml씩을 넣고 6시간동안 배양 후, 새 배양기에 옮기고 24, 48, 72시간동안 배양하여 trypsin 처리로 세포를 분리시킨 후 광학위상차 현미경을 이용, 치근단위면적당 증식된 세포수를 측정하여 다음과 같은 결과를 얻었다. 세포부착실험전 각 군의 치근면 형태를 관찰하였을 때 구연산처리군에서는 교원섬유의 노출부위라고 여겨지는 미세한 돌출구조들을 관찰할 수 있었으며 상아세관의 노출부위라고 여겨지는 함몰양상이 치근활택술군에 비하여 현저하였고 정상치아군에서는 이러한 양상을 관찰할 수 없었다. 실험 각 군 및 대조군 사이에서 세포들의 형태적인 차이점은 분명하지 않았으나 구연산처리군에서 다른 군들보다 초기의 세포부착양상이 다소 빠르게 진행 됨이 관찰되었다. 세포배양 개시 후 6시간이 경과 한 후에는 모든 군에서 공히 세포의 형태가 초기의 구형의 형태에서 편평한 세포의 형태로 변화되기 시작함이 관찰 되었고 24시간 이후에는 모든 군에서 세포들이 치근면에 납작하게 부착되고 일반적인 섬 유아세포의 형태로 변화되어 셰포의 전개가 완성된 양상이 보였다. 세포증식율의 실험에서는 24시간 후 증식된 세포 수는 치근면활택술군에서 가장높게 나타났으며 정상군에서 가장 낮은 수치를 보였으며 48시간 및 72시간후 측정에서는 구연산처리군이 다른 군들에 비해 더 많은 수의 세포증식을 관찰할 수 있었으며 각 군간의 차이는 통계학적으로 유의하였다.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.181-191
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• 1995

The ability of fibroblasts attach to teeth is of paramount imporance in re-establishing the lost connective tissue attachment after periodontal therapy. Tobacco contains a complex mixture of substances including nicotine. various nitrousamines, trace elements. and a variety of poorly characterized substances. The effects of nicotine on fibroblasts have reported an altered morphology and attachment of fibroblasts to substrates and disturbances in protein synthesis and secretion. This study examined the effect of nicotine, a major component of the particulate phase of tobacco smoke, on human gingival fibroblasts and periodontal ligament cells attachment to tissue culture surfaces and cellular activity of human gingival fibroblasts and periodontal ligament cells. Pooled human gingival fibroblasts made from extraction of 3rd molar were utilized between passage 4 and 5 and plated in 96 well plate at 20,000 cells per well. Cell number were determined using 3-(4,5-dimethylthiazole-2-y)2,5-diphenyltetrazolium bromide(MTI) , which is reflection of mitochondrial dehydrogenase activity. The concentration of nicotine used were 0.025, 0.05, 0.1, 0.2 and $0.4{\mu}M$, the average serum concentration for a smoker being approximately $0.1{\mu}M$. The results were as follows : 1. Attachment effects of nicotine on human gingival fibroblasts and periodontal ligament cells Excepts of $0.4{\mu}M$, the effects on attachment with increasing numbers of cells attaching with increasing nicotine concentrations, compared to control group. But over the 60min, return to control value. 2. The effect of cellular activity on human gingival fibroblasts and periodontal ligament cells. The cellular activity of human gingival fibroblasts and periodontal ligament cells were similar or decrease to control value at 1st incubation day. At 2nd incubation day, 0.05, 0.1, 0.2, $0.4{\mu}M$ concentrations were statistically different from control value on gingival fibroblasts group. But at 3rd incubation day, cellular activities of all experimental group were significantly decrease than control group.

• International Journal of Oral Biology
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• 제34권1호
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• pp.37-42
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• 2009

The attachment and adhesion of RAW 264.7 and MC3T3-E1 cells to titanium (Ti) discs with various degrees of roughness was investigated. The attachment, adhesion, and proliferation of these cells were evaluated after 4 hr, 24 hr and 7 day incubations. Both RAW 264.7 and MC3T3-E1 cells showed a time-dependant correlation between attachment and adhesion on the surface of the titanium discs. Both types of cells tended to have higher survival rate on these discs as the surface roughness increased. The percentage of adherent inflammatory RAW 264.7 cells was greater than MC3T3-E1 cells at 24 hr, but this was reversed at 7 days in culture. The morphology of osteoblastic MC3T3-E1 cells at 24 hr, determined using a surface emission microscope (SEM), appeared flattened and spread out while inflammatory RAW 264.7 cells were predominantly spherical in shape. The adhesion of both cell types on the titanium discs was dependant on the levels of fibronectin adsorbed on the disc surface, indicating that serum constituents modulate the efficient adhesion of these cells. Our data indicate that the cellular response to the titanium surface is dependent on the types of cells, surface roughness and serum constituents.

• Journal of Periodontal and Implant Science
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• 제42권4호
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• pp.113-118
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• 2012

Purpose: The aim of this study was to investigate the effects of synthetic fibronectin (FN) fragments, including fibrin binding sites from amino-terminal FN fragments containing type I repeats 1 to 5, on osteoblast-like cell activity. Methods: Oligopeptides ranging from 9 to 20 amino acids, designated FF1, FF3, and FF5, were synthesized by a solid-phase peptide synthesizing system, and we investigated the effects of these peptides on cell attachment and extent of mineralization using confocal microscopy, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and Alizarin red S staining. Results: FF3 and FF5 peptides increased the number of attached human osteoblastic cells, and FF3 administration led to prominent cell spreading. Mineralization was increased in FF3 and FF5 compared to FF1 and the untreated control. Conclusions: Taken together, it can be concluded that the fibrin-binding oligopeptides FF3 and FF5 enhanced cell attachment and mineralization on osteoblast-like cells. These results indicate that FF3 and FF5 have the potential to increase osteoblast-like cell activity. Performing an in vivo study may provide further possibilities for surface modification of biomimetic peptides to enhance osteogenesis, thus improving the regeneration of destroyed alveolar bone.

• Environmental Engineering Research
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• 제18권4호
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• pp.277-281
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• 2013

A dual-chamber microbial fuel cell (MFC) inoculated with Desulfovibrio desulfuricans and supplemented with lactate as an organic fuel was employed in this study. Biofilm formed on the anodic electrode was examined by scanning electron microscopy, revealing that the amount of biofilm was increased with repeated cycles of MFC operation. The maximum current production was notably increased from the first cycle ($1,310.0{\pm}22.3mA/m^2$) to the final cycle ($1,539.4{\pm}25.8mA/m^2$) of MFC run. Coulombic efficiency was also increased from $89.4%{\pm}0.2%$ to $98.9%{\pm}0.5%$. We suggest that the current production efficiency was related to the biomass of biofilm formed on the electrode, which was also increased as the MFC run was repeated. It was also found that D. desulfuricans, which colonized on the electrode, produced filaments or nano-pili. Nano-pili were effective for the attachment of cells on the electrode. In addition, the nano-pili provided a cell-to-cell link and stimulated the development of thicker electroactive biofilm, and therefore, they facilitated electron transfer to the anode. Conclusively, the biofilm of D. desulfuricans enhanced the current production in the MFC as a result of effective attachment of cells and electron transfer from the cell network to the electrode.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.17-20
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• 2001

Whole-cell attachment by covalent linkage, thereby simulating natural and specific attachments, improves the osmotolerance of Saccharomyces cerevisiae cells. The enhanced osmoresistance is correlated with a decrease in the intercellular concentration of trehalose and accompanied by membrane compositional changed. The results obtained indicate that yeast cell-support (physical) contact is sensed and responded to.

• The Journal of Advanced Prosthodontics
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• 제6권5호
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• pp.379-386
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• 2014

PURPOSE. These days, mesenchymal stem cells (MSCs) have received worldwide attention because of their potentiality in tissue engineering for implant dentistry. The purpose of this study was to evaluate various growth inducing factors in media for improvement of acquisition of bone marrow mesenchymal stem cells (BMMSCs) and colony forming unit-fibroblast (CFU-F). MATERIALS AND METHODS. The mouse BMMSCs were freshly obtained from female C3H mouse femur and tibia. The cells seeded at the density of $10^6$/dish in media supplemented with different density of fetal bovine serum (FBS), $1{\alpha}$, 25-dihydroxyvitamin (VD3) and recombinant human epidermal growth factor (rhEGF). After 14 days, CFU-F assay was conducted to analyze the cell attachment and proliferation, and moreover for VD3, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was additionally conducted. RESULTS. The cell proliferation was increased with the increase of FBS concentration (P<.05). The cell proliferation was highest at the density of 20 ng/mL rhEGF compared with 0 ng/mL and 200 ng/mL rhEGF (P<.05). For VD3, although the colony number was increased with the increase of its concentration, the difference was not statistically significant (P>.05). CONCLUTION. FBS played the main role in cell attachment and growth, and the growth factor like rhEGF played the additional effect. However, VD3 did not have much efficacy compare with the other two factors. Improvement of the conditions could be adopted to acquire more functional MSCs to apply into bony defect around implants easily.