• 한국발생생물학회지:발생과생식
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• 제7권2호
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• pp.95-103
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• 2003

세포내 칼슘은 다양한 세포에서 중요한 생리적 반응을 일으키며, ruthenium red와 ryanodine은 중요한 칼슘 조절자로 작용한다. Ruthenium red는 세포내 칼슘 저장고에서의 calcium induced calcium release(CICR)를 저해한다. Ryanodine은 ryanodine 통로를 통한 칼슘 방출을 촉진한다. 본 실험은 두 조절자가 생쥐 난자와 초기배아의 세포내 칼슘이온 농도에 영향을 미치는지 여부와 그 유효농도를 알아보고자 수행하였다 난자 및 초기배아내 칼슘이온 함량 변화는 Fluo-3/AM을 이용하여 공초점 레이저주사 현미경을 사용하여 실시간으로 측정하였다. Ruthenium red는 고농도(30$\mu$M, 300$\mu$M)에서 난자와 초기배아의 세포내 칼슘이온 농도를 저하시켰고, ryandoine은 저농도(0.01$\mu$M)에서 세포내 칼슘이온 농도를 증가시켰지만 고농도(10$\mu$M)에서는 세포내 칼슘이온 농도를 감소시켰다. 본 실험결과를 보면, ruthenium red와 ryanodine은 생쥐의 난자 및 초기배아에서도 세포내 칼슘이온 농도에 영향을 미쳤고, 그 유효농도는 근세포를 포함한 체세포와는 차이가 있었다.

• Journal of Pharmaceutical Investigation
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• 제31권4호
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• pp.241-256
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• 2001

Alginate microspheres, containing fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) or green fluorescent protein (GFP) were prepared and used as a model drug to develop the oral vaccine delivery system. The alginate microspheres were coated with poly-L-lysine or chitosan. Two methods, w/o-emulsion and spray, were used to prepare alginate microspheres. To optimize preparation conditions, effects of several factors on the particle size and particle morphology of microsphere, and loading efficiency of model antigen were investigated. In both preparation methods, the particle size and the loading efficiency were enhanced when the concentration of sodium alginate increased. In the w/o-emulsion preparation method, as the concentration of Span 80 was increased from 0.5% to 2%, the particle size was decreased, but the loading efficiency was increased. The higher the emulsification speed was, the smaller the particle size and loading efficiency were. The concentration of calcium chloride did not show any effect on the particle size and loading efficiency. In the spray preparation method, the particle size was increased as the nozzle pressure $(from\;1\;kgf/m^2\;to\;3\;kgf/m^2)$ and spray rate was raised. Increasing calcium chloride concentration (<7%) decreased the particle size, in contrast to no effect of calcium chloride concentration on the w/o-emulsion preparation method. Alginate microspheres prepared by two methods were different in the particle size and loading efficiency, the particle size of microspheres prepared by the spray method was about $2-6\;{\mu}m$, larger than that prepared by the w/o emulsion method $(about\;2{\mu}m)$, and the loading efficiency was also higher with spray method. Furthermore, drying process for the microspheres prepared by the spray was simpler and easier, compared with the w/o emulsion preparation. Therefore, the spray method was chosen to prepare alginate microspheres for further experiments. Release pattern of FITC-BSA in alginate microspheres was evaluated in simulated intestinal fluid and PBS (phosphate buffered saline). Dissolution rate of FITC-BSA from alginate/chitosan microsphere was lower than that from alginate microsphere and alginate/poly-L-lysine microsphere. By confocal laser scanning microscope, it was revealed that alginate/FITC-poly-L-lysine microspheres were present in close apposition epithelium of the Peyer's patches of rabbits following inoculation into lumen of intestine, which proved that microspheres could be taken up by Peyer's patch. In conclusion, it is suggested that alginate microsphere prepared by spray method, showing a particle size of & $10\;{\mu}m$ and a high loading efficiency, can be used as a model drug for the development of oral vaccine delivery system.

• 대한화장품학회지
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• 제33권2호
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• pp.93-97
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• 2007

일반적으로 음이온 계면활성제는 효소의 disulfide bond를 분해시켜 효소의 활성이 없어진다. 따라서 특정한 캡슐에 효소를 포집하여 안정도를 증대시킨다. 본 연구에서는 polyethylene glycol (PEG), polypropylene glycol (PPG), 그리고 PEG-PPG-PEG block copolymer 등의 폴리올을 이용하여 papain 효소의 안정도를 증대시켰다. Energy dispersive spectroscopy (EDS)와 confocal laser scanning microscope (CLSM) 분석을 통하여 폴리올은 고분자층과 효소의 중간에 위치하며, 이들은 완충액으로 작용하여 효소의 안정도를 증대시키는 것으로 확인하였다. 또한, 이온 복합체를 이용하여 다층 캡슐을 제조하여 wash-off 형태의 세정제에 응용하였다. 세정제 내에서 계면활성제와 물은 효소캡슐의 표면에 분산되었으며, 캡슐의 중앙부분으로 서서히 침투되었다. 반면에 본 연구에서 사용된 sodium lauroyl sarcosinate와 polyguaternium-6는 물이 효소부분으로 침투하지 않는 것을 in vivo 시험을 통하여 확인하였다.

• Archives of Pharmacal Research
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• 제29권10호
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• pp.859-865
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• 2006

With an approach to study the anti-tumor effects and mechanism of selenium compound, we investigated the anti-tumor activity and mechanism of $Na_5SeV_5O_{18}{\cdot}3H_2O$ (NaSeVO) in K562 cells. The results showed that $0.625{\sim}20\;mg/L$ NaSeVO could significantly inhibit the proliferation of K562 cells in vitro in a time- and concentration-dependent manner as determined by microculture tetrazolium (MTT) assay, the IC50 values were 14.41 (4.45-46.60) and 3.45 (2.29-5.22) mg/L after 48 hand 72 h treatment with NaSeVO respectively. In vivo experiments demonstrated that i.p. administration of 5, 10 mg/kg NaSeVO exhibited an significant inhibitory effect on the growth of transplantation tumor sarcoma 180 (S180) and hepatoma 22 (H22) in mice, with inhibition rate 26.8% and 58.4% on S180 and 31.3% and 47.4% on H22, respectively. Cell cycle studies indicated that the proportion of G0/G1 phase was increased at 2.5 mg/L while decreased at 10 mg/L after treatment for 24, 48 h. Whereas S phase was decreased at 2.5-5 mg/L and markedly increased at 10 mg/L after treatment for 48 h. After treatment for 24 h, 10 mg/L NaSeVO also markedly increased S and G2/M phases. Take together, the result clearly showed that NaSeVO markedly increased S and G2/M phases at 10 mg/L. The study of immunocytochemistry showed that the expression bcl-2 is significantly inhibited by 10 mg/L NaSeVO, and bax increased. Morphology observation also revealed typical apoptotic features. NaSeVO also significantly caused the accumulation of $Ca^{2+}$ and $Mg^{2+}$, reactive oxygen species (ROS) and the reduction of pH value and mitochondrial membrane potential in K562 cells as compared with control by confocal laser scanning microscope. These results suggest that NaSeVO has anti-tumor effects and its mechanism is attributed partially to apoptosis induced by the elevation of intracellular $Ca^{2+}$, $Mg^{2+}$ and ROS concentration, and a reduction of pH value and mitochondria membrane potential (MMP).

• 대한치과보철학회지
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• 제39권1호
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• pp.71-83
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• 2001

The purpose of this study was to compare the effects of various surface treatments by measuring removal torque on bone healing around titanium implants. 40 Screw-shaped cp titanium implants with length of 4mm, outer diameter of 3.75mm, and pitch-height of 0.5mm were used Group 1 was left as machined(control), Group 2 was blasted with $50{\mu}m\;Al_2O_3$, group 3 was blasted and etched in etching solution($NH_4OH : H_2O_2:H_2O= 1 : 1 : 5$) at $90^{\circ}C$ for 1 minute group 4 was blasted and oxidated under pure oxygen at $800^{\circ}C$. The implant surface roughness was analyzed with SEM and CLSM(Confocal Laser Scanning Microscope) and implants were placed in proximal tibial metaphysis of 10 New Zealand White rabbits. After 3 months of healing period, removal torque of each implant was measured to compare bone healing around implant. The results obtained were as follows 1. In SEM view, blasting increased the roughness of the surface, but etching of that rough surface decreased the roughness due to the removal of the tip of the peak. Oxidation also decreased the roughness due to formation of needle-like oxide grains on the implant surface. 2. The Sa value from CLSM was least in the machined group($0.47{\mu}m$), greatest in blasted group($1.25{\mu}m$), and the value decreased after etching($0.91{\mu}m$) and oxidation($0.94{\mu}m$). 3. The removal torque of etched group(24.5Ncm) was greater than that of machined group(16.7Ncm) (P<0.05), and was greatest in the oxidated group(40.3Ncm) and the blasted group(34.7Ncm).

• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.301-309
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• 1997

본 연구에서는 체외수정, 난자내 정자 직접주입, 난자내 정자 두부 미두 주입 후의 핵과 미세소관의 변화를 관찰하였다. 핵과 미세소관의 움직임은 형광염색을 실시한 후 공초점주사현미경을 이용하여 관찰하였다. 체외수정에서 관찰된 바와 동일하게 정자를 난자에 직접주입 한 직후 정자 중편부에서 성상체가 형성되었고, 이 성상체에 의해 자성 웅성 전핵이 융합되는 것으로 관찰되었다. 그러나 난자내 정자를 직접주입하였을 경우 웅성전핵으로 발달하는 비율이 낮았다. 이는 주입된 정자가 원형질막과 perinuclear theca에 싸인 체 난자내로 들어가 난자내의 sperm nucleus decondensing factor와 정자 핵과의 반응이 억제되기 때문으로 생각된다. 정자 두부 만을 주입하였을 경우 성상체가 형성되지 않았지만 자성 웅성 전핵 사이 또는 그 주위에서 두터운 미세소관층이 관찰이 되었다. 따라서 소에 있어서는 정자의 중편부에 위치하여 microtubule organizing center (MTOC)의 역할을 하는 중심립 또는 중심체 없이도 모계에서 유래된 미세소관이 형성되어 이것이 전핵의 융합과 세포분열에 관여하는 것으로 생각된다. 정자의 미부 만을 주입하였을 경우 성상체가 형성이 되지 않았으며, 자성핵 사이에 형성된 미세소관과 떨어져서 관찰되었다. 따라서 주입된 정자의 꼬리는 미세소관형성과 관련이 없는 것으로 생각된다. 이러한 결과는 소에 있어서, 수정 시 정자로부터 유래되는 중심립 또는 중심체가 없이도 미세소관을 형성하여 미세소관에 의해 이후의 배발달이 정상적으로 일어남을 보여주고 있다.

• 미생물학회지
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• 제50권4호
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• pp.360-367
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• 2014

Candida albicans는 면역력이 약화된 환자의 표재성에서 전신적 감염까지 다양한 부위에서 감염을 유발시킬 수 있는 기회 감염적 병원성 진균이다. C. albicans는 효모형에서 균사형으로 변환될 수 있으며 이 때 바이오필름을 형성할 수 있다. 바이오필름과 관련된 C. albicans의 감염은 일반적으로 통상적인 항진균제에 대해 내성을 보이므로 새로운 항진균제에 대한 개발이 절실하다. 대황(Rheum undulatum)은 전통적으로 한국과 중국에서 하제나 소염제로 사용되는 약용 식물이다. 본 연구의 목적은 R. undulatum이 캔디다증 환자로부터 분리한 C. albicans 바이오필름 형성 균주에 대한 바이오필름 형성 억제효과와 이에 대한 항진균 활성 기작을 알아보는 것이다. R. undulatum (0.098 mg/ml)은 12종의 바이오필름 형성 임상균주의 캔디다 바이오필름을 $49.4{\pm}6.0%$ 감소시켰고 C. albicans의 폴리스티렌 표면으로의 부착을 억제시켰다. CFDA, AM과 propidium iodide로 이중 염색한 결과 R. undulatum은 C. albicans의 세포막을 손상시켰으며 propidium iodide와 neutral red로 염색하여 공초점 레이저 현미경과 위상차 현미경으로 관찰한 결과 C. albicans의 세포용해를 야기함을 관찰할 수 있었다. Crystal violet 흡수율 실험으로 R. undulatum에 의한 세포막 투과성의 변화를 관찰하였다. 따라서 R. undulatum은 세포막의 손상과 세포막의 투과성 변화로 야기된 세포의 용해와 관련된 항진균 활성이 C. albicans의 바이오필름 형성을 억제하는 것으로 보여진다. 본 연구의 결과는 R. undulatum이 바이오필름과 관련된 캔디다의 감염을 치료하고 제거하기 위한 천연물 기반 항진균제 개발에 대한 좋은 후보물질임을 보여준다.

• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.243-253
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• 2000

The purpose of this in vitro study was to evaluate dentin bonding by two different dentin bonding systems(DBS) using acetone based primer or adhesive [All Bond 2(AB2), One Step(OS)] when they were applied by wet or dry bonding technique. Morphology of resin-dentin interface and hybrid layer thickness(HLT) were investigated using Confocal Laser Scanning Microscope(CLSM) and compared to shear bond strength(SBS). 72 extracted sound human molars were randomly divided into 4 groups of 18 teeth each - Group 1.(AW); AB2 by wet bonding. Group 2(AD); AB2 by dry bonding. Group 3.(OW); OS by wet bonding, Group 4.(OD); OS by dry bonding. In 6 teeth of each group, notch-shaped class V cavities(depth 2mm) were prepared on buccal and lingual surface at the cementoenamel juction(12 cavities per group). To obtain color contrast in CLSM observation, bonding resins of each DBS were mixed with rhodamine B and primer of AB2 was mixed with sodium fluorescein. Prepared teeth of each group were treated with AB2, OS, respectively according to the manufacturer's instructions except for dentin surface moisture treatment after acid etching. In group 1 and 3, after acid etching, excess water was removed with wet tissue(Kimwipes), leaving consistently shiny, visibly hydrated dentin surface. In group 2 and 4, dentin surface was dried for 10 seconds at 1 inch distance. The treated teeth were then packed with composite resin(${\AE}$litefil) and light-cured. 12 microscopic samples($60{\sim}80{\mu}m$ thickness) of each group were obtained after longitudinal section and grinding(Exakt cutting and grinding system). Morphological investigation of resin-dentin interface and HLT measurement using CLSM were done. For measurement of SBS, remaining 12 teeth of each group were flattened occlusally to remove all enamel and grinded to 500 grit SiC(Pedemet Specimen Preparation Equipment). After applying DBS on the exposed dentin surface, composite resin was applied in the shape of cylinder, which has 5mm diameter, 1.5mm thickness, and light cured. SBS was measured using Instron with a crosshead speed of 0.5mm/min. It was concluded as follows, 1. HLT of AW(mean: $2.59{\mu}m$) was thicker than any other group, and followed by AD, OW, OD in descending order(mean; 2.37, 2.28, $1.92{\mu}m$). Only OD had statistically significant differences(p<0.05) to AW and AD. 2. There were intimate contact of resin and dentin at the interface in wet bonding groups, but gaps or irregular interfaces were observed in dry bonding groups. 3. The length, diameter, density of resin tags were various even in the same group without significant differences between groups and lots of adhesive lateral branches were observed. 4. There were no statistically significant difference of SBS between AB2 and OS, but SBS of wet bonding groups were significantly higher(p<0.05) than dry bonding groups. 5. There were no consistent relationships between HLT and SBS.

• Tribology and Lubricants
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• 제39권2호
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• pp.49-55
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• 2023

Currently, the demand for green technologies toward a sustainable future is rapidly increasing due to growing concern over environmental issues. Methanol is biodegradable and can provide clean combustion to reduce sulfur oxide and nitrogen oxide emissions, and therefore it is a candidate fuel for marine engines. However, the effect of methanol on tribological characteristic degradation should be addressed for methanol-fueled engines. In this study, the methanol addition effects on tribological characteristic degradation is experimentally assessed using a pin-on-disk tribo-tester. Ni-based alloy is used as a target material due to its broad applicability as an engine component material. For a lubricant, engine oil with and without methanol are used. The tests are conducted for up to 10,000 cycles under boundary lubrication while the change in friction force is monitored. Additionally, the wear rate is determined based on laser scanning confocal microscope data. An additional test in which methanol is added at regular intervals is performed with an aim to directly observe its effect on friction. Overall, the friction coefficient increases slightly with increasing methanol concentration. Furthermore, the wear rate of the pin and disk increase significantly with methanol addition. The results also indicate that the friction increases instantaneously with methanol addition at the contacting interface. These findings may be useful for better understanding the methanol effect on the tribological characteristics of Ni-based alloys for methanol-fueled engines with improved performance.

• 대한치과보철학회지
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• 제53권4호
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• pp.337-344
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• 2015

목적: 본 연구의 목적은 지대치 삭제의 정확도와 metal coping의 변연적합도와의 상관관계를 알아보는 데 있다. 이를 통해, 세 가지 다른 제작 방식 (주조, milling, 기법)이 이 상관관계에 미치는 영향을 비교해 보고자 한다. 재료 및 방법: 두 개의 master medel을 서로 다른 방식으로 제작하였다; 첫 번째 모델은 치과의사에 의해 deep chamfer margin을 가지도록 지대치 삭제된 것이고, 두 번째 모델은 3-D designing software program을 이용하여 동일한 삭제원칙에 따라 제작되었다. 각각의 모델에 대하여 세 가지 제작 방식으로 코발트-크롬 코핑을 12개씩 제작하여, 총 72개의 시편을 얻었다. 각 시편을 master model상에 적합시키고 공초점 레이저 주사 현미경으로 변연적합도를 측정하였다. 결과: SLS system (P=.0231)과 주조방식(P<.0001)에서는 computer designed model이 hand prepared model에 비하여 유의하게 우수한 변연적합도를 보였다. 그러나 milling group에서는 두 모델 간에 유의한 차이를 나타내지 않았다(P=.9962). 결론: 본 연구에 한하여, 지대치 삭제의 정확도가 금속 코핑의 변연적합도에 미치는 영향은 그 제작 방식에 따라 달랐다. 제작 방식에 따른 변연적 합도는 SLS system이 가장 우수하였고 지대치 삭제의 정확도에 의해 영향을 받았다. 한편, milling 방식은 세 가지 방식 중 가장 큰 변연 격차를 나타내었으며 지대치 삭제의 정확도에 영향을 받지 않았다.