• Investigative Magnetic Resonance Imaging
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• 제11권1호
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• pp.1-9
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• 2007

심장의 영상화에 장애가 되는 요인은 심장 운동, 호흡, 심장 내 혈류 등에 의한 인공물(artifact) 과 심장 조직의 용적이 작음으로 인한 낮은 신호 대 잡음비 등이 있다. 심장 운동에 의한 화질 저하를 막기 위해 신속영상기법(fast imaging technique) 을 이용하여 심장 운동의 특정 위상(phase) 에서만 영상을 얻는 심장동기(cardiac gating) 방법을 이용하고 있다. MRI를 이용한 심장의 검사는 심장의 형태, 심실 기능, 심근 관류, 심근 대사, 관상동맥 영상 등을 대상으로 한다. 심장의 형태적 진단에 있어서 심근내 수분의 정도와 지방조직을 보기 위해 이중(double) 혹은 삼중역전회복기법(triple inversion recovery technique) 을 사용한다. 심근관류검사를 위해서는 조영증강신속경사에코법(contrast-enhanced fast gradient echo technique)을 사용하여 일차통과조영증강(first-pass enhancement) 을 검사한다. 또한 10-15분 지연영상을 얻어 심근내 조영제의 재분포를 검사하여 만성심근경색 등의 심근파괴부위를 확인한다. 심실기능 평가를 위해서는 신속경사에 코법을 이용한 영화영상(cine image) 이 사용되며 심실의 국소적 운동이상 및 심실기능의 정량적 검사가 가능하다. MRI는 관상동맥영상을 제외한 포괄적 심장검사에 실용성이 있다. 특히 지연영상은 다른 검사장비에선 얻을수 없는 유용한 정보이다.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.151-163
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• 1997

The purpose of this study was to evaluate on the biodegradability, biocompatibility and tissue regenerative capacity of synthetic biodegradable $mernbranes-Resolut^{(R)}$, $Guidor^{(R)}$ and $Biomesh^{(R)}$. To evaluate the cell attachment on the membranes, in vitro, the number of gingival fibroblasts attached to each membrane was counted by hemocytometer. Cytotoxicity test for the membranes was performed by MTT test with gingival fibroblast For evaluation of guided- bone regenerative potential, the amount of new bone formation in the rat calvarial defects(5mm in diameter) beneath the membranes was observed for two weeks and examined of the specimens by Massons trichrome staining. Biodegradability was observed for 2, 4, 8 and 12 weeks after implantation of each materials under the skin of rats and examined the specimens with H & E staining. The number of cell attachment were the greatest in $Biomesh^{(R)}$ and followed by $Resolut^{(R)}$. Cell viability of three membranes was almost similar levels. Biodegradability of $Resolut^{(R)}$ was the highest among three membrane and the potential of guided bone regeneration was the greatest in the $Biomesh^{(R)}$ and $Resolut^{(R)}$ was followed. These results suggested that commercially available biodegradable membranes were non-toxic and highly potential to guided bone regeneration.

• 한방재활의학과학회지
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• 제18권2호
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• pp.81-96
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• 2008

Objectives : This study was performed to investigate inhibitory effects of Gamipalmul-tang($jiaweibawu-t{\bar{a}}ng$) on the hematological and histological changes of obese mice. Methods : C57BL/6 mice were divided into four groups (normal group, high fat diet with normal saline, high fat diet with reductil, high fat diet with Gamipalmul-tang($jiaweibawu-t{\bar{a}}ng$) and fed for 8 weeks. Body weight change, final increase of body weight, ALT, AST, creatinine, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, glucose, cell viability by cytotoxicity, the expression of ${\beta}3AR$ in 3T3-L1 cell, the expression of leptin, ${\beta}3AR$ and serotonin in adipocyte tissue and size of adipocyte were observed in 8 weeks. Results : 1. In 3T3-L1 cell. the expression of ${\beta}3AR$ was increased significantly. 2. The final increase of body weight in obese-mouse were decreased significantly. 3. The level of AST, ALT were decreased significantly. 4. The level of LDL-cholesterol was decreased significantly and HDL-cholesterol was increased significantly. 5. The levels of triglyceride was decreased and leptin and glucose were decreased significantly. 6. In adipocyte tissue, the expression of ${\beta}3AR$ were increased significantly. 7. In adipocyte tissue, the expression of leptin and serotonin were decreased significantly. 8. The size of Adipocyte was decreased. Conclusions : On the basis of these results, we concluded that Gamipalmul-tang($jiaweibawu-t{\bar{a}}ng$) has inhibitory effects in rat.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.721-733
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• 2018

BACKGROUND: Because three-dimensional (3D) models more closely mimic native tissues, one of the goals of 3D in vitro tissue models is to aid in the development and toxicity screening of new drug therapies. In this study, a 3D skin wound healing model comprising of a collagen type I construct with fibrin-filled defects was developed. METHODS: Optical imaging was used to measure keratinocyte migration in the presence of fibroblasts over 7 days onto the fibrin-filled defects. Additionally, cell viability and growth of fibroblasts and keratinocytes was measured using the $alamarBlue^{(R)}$ assay and changes in the mechanical stiffness of the 3D construct was monitored using compressive indentation testing. RESULTS: Keratinocyte migration rate was significantly increased in the presence of fibroblasts with the cells reaching the center of the defect as early as day 3 in the co-culture constructs compared to day 7 for the control keratinocyte monoculture constructs. Additionally, constructs with the greatest rate of keratinocyte migration had reduced cell growth. When fibroblasts were cultured alone in the wound healing construct, there was a 1.3 to 3.4-fold increase in cell growth and a 1.2 to 1.4-fold increase in cell growth for keratinocyte monocultures. However, co-culture constructs exhibited no significant growth over 7 days. Finally, mechanical testing showed that fibroblasts and keratinocytes had varying effects on matrix stiffness with fibroblasts degrading the constructs while keratinocytes increased the construct's stiffness. CONCLUSION: This 3D in vitro wound healing model is a step towards developing a mimetic construct that recapitulates the complex microenvironment of healing wounds and could aid in the early studies of novel therapeutics that promote migration and proliferation of epithelial cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권4호
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• pp.277-286
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• 2006

In the present study, I investigated the effects of N-methyl-D-aspartate (NMDA), arachidonic acid (AA), and Nitric Oxide Synthase Inhibitor (NOS-I), alone or in combination, on the viability of cultured primary normal human oral keratinocytes (NHOK). Specifically, we examined whether AA and NOS-I could protect primary NHOK from glutamate cytotoxicity. The purpose of this study was therefore the preliminary study for the examination of the interaction between these agents and NHOK in order to elucidate the mechanisms by which epithelial growth and regeneration are regulated. NHOK were obtained from gingival tissue of 20 individuals aged 20 to 29, and third passage (P3) cells were used for this study. Cell viability was measured by the MTT assay. NMDA and NNA, a calcium dependent NOS inhibitor, induced an initial increase in cell number, which subsequently decreased by the $7^{th}$ day. Low concentration of AA ($0.5\;{\mu}M$ & $1\;{\mu}M$) induced an increase in cell number while high concentrations of AA ($5\;{\mu}M$ & $10\;{\mu}M$) induced a decrease in cell number. The decrease in cell number induced by NMDA at the $7^{th}$ day was abolished by the addition of low concentrations of AA ($0.5\;{\mu}M$ & $1\;{\mu}M$) or NOS inhibitors. Low concentrations of AA ($0.5\;{\mu}M$ & $1\;{\mu}M$) or NOS inhibitors may protect the NHOK from NMDA induced cytotoxicity. These reactions might be related to the NMDA receptor in the cell and the change of the intracellular calcium ion concentration.

• 한국정밀공학회지
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• 제33권1호
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• pp.63-67
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• 2016

We present a method of fabricating poly (lactic-co-glycolic acid) (PLGA) porous microfibers using a pore template. PLGA microfibers were synthesized using a glass capillary tube in a poly-(dimethylsiloxane) (PDMS) microfluidic chip. Gelatin solution was used as a porous template to prepare pores in microfibers. Two phases of PLGA solutions in different solvents-DMSO (dimethyl sulfoxide) and DCM (dichloromethane)-were used to control the porosity and strength of the porous microfibers. The porosity of the PLGA microfibers differed depending on the ratio of flow rates in the two phases. The porous structure was formed in a spiral shape on the microfiber. The porous structure of the microfiber is expected to improve transfer of oxygen and nutrients, which is important for cell viability in tissue engineering.

• Current Optics and Photonics
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• 제7권1호
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• pp.65-72
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• 2023

The motion of organelles inside a cell is an important intrinsic indicator for assessing cell physiology and tissue viability. Dynamic contrast full-field optical coherence tomography (D-FFOCT) is a promising imaging technology that can visualize intracellular movements using the variance of temporal interference signals caused by biological motions. However, double-path interferometry in D-FFOCT can be highly vulnerable to surrounding noise, which may cause turbulence in the interference signals, contaminating the sample dynamics. Therefore, we propose a method for stabilized D-FFOCT imaging in noisy environments by using common-path interferometry in D-FFOCT. A comparative study shows that D-FFOCT with the proposed method achieves stable dynamic contrast imaging of a scattering phantom in motion that is over tenfold more noise-insensitive compared to the conventional one, and thus this imaging capability can provide cleaner motion contrast images. With the proposed approach, the intracellular dynamics of biological samples are imaged and monitored.

• Tuberculosis and Respiratory Diseases
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• 제58권4호
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• pp.375-384
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• 2005

목 적 : 폐포상피세포의 LPS 전처치 여부에 따라 HSP70 유도가 추가 LPS 자극에 의한 IL-6 생성능 및 세포생존도에 미치는 영향과 그 기전에 HSP70이 관여하는 지를 관찰하였다. 방 법 : 쥐의 폐포상피세포를 배양하여 LPS 전처치군과 비처치군으로 분류한 후, 각 군을 다시 대조군, quercetin 단독투여군, HSP70 유도군, HSP70 억제군으로 나누어 추가 LPS자극 후에 HSP70 발현, IL-6 생성능 및 세포생존도를 관찰하였다. HSP70 유도에는 sodium arsenite(SA)를, HSP70 억제에는 quercetin을 사용하였으며, HSP70 발현은 western blot으로, IL-6 생성능은 ELISA로 측정하였다. 세포생존도는 단순화한 MTT 측정법으로 관찰하였다. 결 과 : 세포 생존도에 영향을 미치지 않으면서 충분한 HSP70 발현을 유도하는 SA 농도는 $50{\mu}M$, HSP70 발현을 억제하는 quercetin 농도는 $100{\mu}M$이었다. LPS 전치치 여부에 상관없이 HSP70 유도군은 대조군에 비해 추가 LPS자극에 의한 IL-6 생성능이 현저히 감소하였으며, HSP70 억제군은 HSP70 유도군에 비해 추가 LPS자극에 의한 IL-6 생성능이 유의하게 다시 증가하였다. 세포생존도는 LPS 비처치군에서는 각 실험군이 대조군에 비해 유의하게 증가하였지만, LPS 전처치군에서는 각 군 간에 차이가 없었다. 결 론 : 이와 같은 결과는 쥐폐포상피세포에서 LPS 전처치 후에 HSP70 유도를 하면 세포생존도에는 영향을 미치지 않으면서 추가 LPS 자극에 따른 IL-6 생성능이 억제되며, 이러한 현상이 나타나는 기전에는 HSP70 자체가 중요한 역할을 하고 있음을 시사한다.

• Archives of Plastic Surgery
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• 제43권3호
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• pp.237-241
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• 2016

Background Adipose-derived stem cells (ASCs) have applications in regenerative medicine based on their therapeutic potential to repair and regenerate diseased and damaged tissue. They are commonly subject to oxidative stress during harvest and transplantation, which has detrimental effects on their subsequent viability. By functioning as an antioxidant against free radicals, melatonin may exert cytoprotective effects on ASCs. Methods We cultured human ASCs in the presence of varying dosages of hydrogen peroxide and/or melatonin for a period of 3 hours. Cell viability and apoptosis were determined with propidium iodide and Hoechst 33342 staining under fluorescence microscopy. Results Hydrogen peroxide (1-2.5 mM) treatment resulted in an incremental increase in cell death. 2 mM hydrogen peroxide was thereafter selected as the dose for co-treatment with melatonin. Melatonin alone had no adverse effects on ASCs. Co-treatment of ASCs with melatonin in the presence of hydrogen peroxide protected ASCs from cell death in a dose-dependent manner, and afforded maximal protection at $100{\mu}M$ (n=4, one-way analysis of variance P<0.001). Melatonin co-treated ASCs displayed significantly fewer apoptotic cells, as demonstrated by condensed and fragmented nuclei under fluorescence microscopy. Conclusions Melatonin possesses cytoprotective properties against oxidative stress in human ASCs and might be a useful adjunct in fat grafting and cell-assisted lipotransfer.

• International Journal of Oral Biology
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• 제38권4호
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• pp.141-147
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• 2013

It has been established that berberine has strong antimicrobial effects. Little is known however regarding the antimicrobial activity of berberine against endodontic pathogenic bacteria or its cytotoxicity in human oral tissue cells. The antibacterial properties of berberine were tested against 5 strains of Enterococcus faecalis and type strains of Aggregatibacter actinomycetemcomitans, Prevotella nigrescens, Prevotella intermedia, and Tannerella forsythia, which are involved in endodontic infections. Antimicrobial activity was evaluated through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) measurements. The viability of normal human gingival fibroblast (NHGF) cells after exposure to berberine was measured using a methyl thiazolyl tetrazolium (MTT) assay. The data showed that berberine has antimicrobial effects against A. actinomycetemcomitans with an MIC and MBC of $12.5{\mu}g/ml$ and $25{\mu}g/ml$, respectively. In the cytotoxicity studies, cell viability was maintained at 66.1% following exposure to $31.3{\mu}g/ml$ berberine. Overall, these findings suggest that berberine has antimicrobial activity against the tested bacteria. Nevertheless, lower concentrations in combination with other reagents will need to be tested before these in vitro results can be translated to clinical use.