• 한국환경보건학회지
• /
• 제23권2호
• /
• pp.98-105
• /
• 1997

The study on the cytotoxicity of heavy metals was carried out to evaluate the cytotoxic effect of those on mouse L929 fibroblast cell in 96-well microtiter plates. The cytotoxicity was assayed by the neutral red, tetrazolium MTT, total protein, micronuclei test. The cytotoxicity of the heavy metals by neutral red and tetrazolium MTT was showed in order, cadmium > zinc > nickel for the cationic metals tested. The effect of metal-metal interaction on the cytotoxicity showed a marked reduction of cadmium toxicity by zinc, to a lesser degree, by nickel. The amount of total protein in treated group added heavy metals was less than that of the control and treated cadmium alone was less than those of combination with nickel or zinc. At midpoint cytotoxicity values of heavy metals, the frequency of micronuclei on the cell treated heavy metals was more than that of control and treated cadmium alone was more than those of combination with nickel or zinc. From those results, it could be suggested that the heavy metals decreased the viability of mouse fibroblast L929 cells in a concentration-dependent manner and have cytogenic toxic effects, but mixed group decreased the cytotoxic and cytogenic toxicity on L929 cells.

• 한방재활의학과학회지
• /
• 제19권1호
• /
• pp.187-199
• /
• 2009

Objectives : The electroacupuncture was generally has been used in oriental medicine doctors. In recent years, there have been a few studies about safety and stability of acupuncture needle in itself, but then again research of acupuncture needle safety and stability on applying electroacupuncture have been insignificant. Therefore we investigated the safety and change in mechanical characteristic of acupuncture needle in electroacupuncture therapy. Methods : We observed mechanical characteristic change by SEM(Scanning Electron Microscope) and EDX(Energy Dispersive X-ray Spectroscopy), evaluated the hardness by vickers hardness tester. We used MTT assay and cell stain to study about biocompatibility of electroacupuncture. Results : In this study, any corrosion of material, alternation of elements, and change of hardness were not observed in surface analysis using SEM and EDX. In cytotoxity evaluation using MTT assay and cell stain, cell survival rate was low when practicing the electroacupuncture for more than 3 hours. Conclusions : Change of mechanical property was not observed based on the test results using surface analysis and hardness estimation by the electroacupuncture. And considering the biocompatibility, electroacupuncture was thought to be safe in an hour based on cytotoxity evaluation using MTT assay and cell stain.

• Journal of Plant Biotechnology
• /
• 제3권2호
• /
• pp.83-88
• /
• 2001

A cell culture system of poplar (Populus alba x P.glandulosa) was established to test four different methods for evaluation of cellular stresses. Two different kinds of stresses were given to the cultures by adding either Pb(NO$_3$)$_2$ or paraquat and the cellular responses were monitored during a week period. While fresh weight reduction was observable in two days after the treatment of Pb(NO$_3$)$_2$, such changes were apparent only in later stage in paraquat treated cultures. Cells in paraquat treated cultures in the first 3 days showed no alteration in fresh weight as compared to untreated cultures, but had their MTT reducing activities completely inhibited. Neither Evans blue staining nor ion conductivity of the medium was consistent with fresh weight changes of the cultures. Overall, cell clumps formed during suspension culture appeared to interfere with staining and washing reactions and thus cause the assays unreliable. Among the four methods examined, fresh weight changes and MTT reducing activity appeared to be the most reliable and consistent.

• 대한소아치과학회지
• /
• 제32권1호
• /
• pp.55-66
• /
• 2005

천궁의 메탄올 수용액 추출물의 진정 작용을 밝히기 위하여 staircase test를 시행하였으며, 근육이완 효과를 검색하기 위하여 rotarod test를 시행하였다. 진정 작용의 기전 구명을 위하여 GABA 및 glycine 수용체에 작용하는 약물인 picrotoxin, yohimbine, isoniazid, strychnine 등의 약물을 이용하여 발작 유도에 걸리는 시간을 비교 관찰하였다. 또한 생체에서의 안전성을 검증하기 위하여 Irwin의 행동시험 및 신경세포에 대한 독성을 평가하기 위하여 MTT test를 실시하여 다음의 결과를 얻었다. 1. Staircase 실험에서 천궁 추출물을 10mg/kg 용량으로 경구 투여했을 때 climbing수는 대조군과 차이가 없었으나, rearing수에서는 대조군에 비하여 42%의 감소를 보였다. 2. 30mg/kg의 용량으로 경구 투여했을 때, climbing수는 대조군과 차이가 없었으나, rearing수에서는 51%의 감소를 유발하였다. 3. 근육이완 작용을 탐색하기 위한 rotarod 실험에서는 대조군과 차이를 나타내지 않았다. 4. 천궁 추출물의 투여는 picrotoxin, isoniazid, yohimbine에 의한 발작에서는 큰 변화를 유발하지 않았으나, strychnine에 의한 발작 유도시간은 41%의 증가를 유발하였다. 5. 일반 행동에서도 특이한 변화를 유발하지 않았으며, 신경세포에 적용했을 때 특이한 독성 반응을 나타내지 않았다. 천궁의 메탄을 수용액 추출물은 현저한 진정 작용을 유발하며, 그 작용 기전으로서 glycine의 작용을 증가시켜 chloride ion의 세포내 유입으로 인한 억제성 신경전도를 유도한다고 사료된다. 또한 근육이완 작용도 나타나지 않았으며, 특이한 생체독성도 유발되지 않은 것으로 보아, 향후 치과임상에서 진정요법의 한 수단으로서 사용될 수 있다는 가능성을 제시한다.

• 한국버섯학회지
• /
• 제9권2호
• /
• pp.84-86
• /
• 2011

국내자생 야생버섯의 항염증 활성검증을 위해 7월~8월에 채집된 버섯을 메탄올 추출하여 DMSO의 희석한 후 Nitric oxide 저해능을 분석하였다. 30여종의 버섯 추출물을 세포활력도를 측정하기 위해 MTT 분석결과 12개의 버섯추출물이 비교적 안정된 세포활력도를 보였으며, nitric oxide 저해능을 양성대조군(LPS)와 비교한 결과 Amanita virgineoides:흰가시광대버섯, Tylopilus neofelleus:제주쓴맛그물버섯, Armillariella tabescens:뽕나무버섯붙이, Amanita abrupta:양파광대버섯, Agaricus subrutilescens:진갈색주름버섯, Boletus subvelutips 7종의 버섯은 18%이상의 우수한 nitric oxide저해능을 보였다.

• Journal of Periodontal and Implant Science
• /
• 제38권sup2호
• /
• pp.299-308
• /
• 2008

Purpose: The aim of this study was to evaluate adhesion and gene expression of the MC3T3-E1 cells cultured on machined titanium surface (MS) and anodized titanium surface (AS) using MTT test, Scanning electron micrograph and cDNA microarray. Materials and Methods: The MTT test assay was used for examining the proliferation of MC3T3-E1 cells, osteoblast like cells from Rat calvaria, on MS and AS for 24 hours and 48 hours. Cell cultures were incubated for 24 hours to evaluate the influence of the substrate geometry on both surfaces using a Scanning Electron Micrograph (SEM). The cDNA microarray Agilent Rat 22K chip was used to monitor expressions of genes. Results: After 24 hours of adhesion, the cell density on AS was higher than MS (p < 0.05). After 48 hours the cell density on both titanium surfaces were similar (p > 0.05). AS had the irregular, rough and porous surface texture. After 48 hours incubation of the MC3T3-E1 cells, connective tissue growth factor (CTGF) was up-regulated on AS than MS (more than 2 fold) and the insulin-like growth factor 1 receptor was down-regulated (more than 2 fold) on AS than MS. Conclusion: Microarray assay at 48 hours after culturing the cells on both surfaces revealed that osteoinductive molecules appeared more prominent on AS, whereas the adhesion molecules on the biomaterial were higher on MS than AS, which will affect the phenotype of the plated cells depending on the surface morphology.

• 대한치주과학회:학술대회논문집
• /
• 대한치주과학회 1999년도 제39회 종합학술대회 연제초록
• /
• pp.30-30
• /
• 1999

• 방송공학회논문지
• /
• 제27권3호
• /
• pp.361-368
• /
• 2022

VVC(Versatile Video Coding) 표준에서는 블록 분할 기술로써 QT+MTT(Quaternary Tree plus Multi-Type Tree) 분할 구조가 채택되었다. QT+MTT 분할 구조는 우수한 부호화 효율을 제공하지만, BT(Binary Tree)와 TT(Ternary Tree) 분할 타입으로 인한 블록 분할의 확장성 때문에, 전반적인 부호화 복잡도가 크게 증가하였다. 본 논문에서는 MAE(Mean of the Absolute Error)에 기한반 예측 정확도 함수를 이용하여, BT와 TT 분할 타입을 위한 화면간 CU(Coding Unit) 분할 알고리즘의 고속화 기법을 제안한다. 제안하는 고속화 기법은 부호화 복잡도 감소율의 일관성과 안정적이고 낮은 부호화 손실을 통해, 저복잡도 VVC 부호화기 설계 시에 실용적인 방법으로 활용될 수 있다. RA(Random Access) 실험 환경에서 휘도 성분의 BD(Bjontegaard Delta) 비트율은 1.0%~2.1% 증가한 반면에 부호화 시간 복잡도는 24.0%~31.7% 감소시킬 수 있었다.

• Journal of Microbiology and Biotechnology
• /
• 제19권8호
• /
• pp.792-802
• /
• 2009

Antimicrobial peptides (AMPs) are considered to be a promising alternative to conventional antibiotics for future generations. We identified four novel hexapeptides with antimicrobial activity: KCM11 (TWWRWW-$NH_2$), KCM12 (KWRWlW-$NH_2$), KCM21 (KWWWRW-$NH_2$), and KRS22 (WRWFIH-$NH_2$), through positional scanning of a synthetic peptide combinatorial library (PS-SCL). The ability of these peptides to inhibit the growth of a variety of bacteria and unicellular fungi was evaluated. KCM11 and KRS22 preferentially inhibited the normal growth of fungal strains, whereas KCM12 and KCM21 were more active against bacterial strains. Bactericidal activity was addressed in a clear zone assay against phytopathogenic bacteria, including Pectobacterium spp., Xanthomonas spp., Pseudomonas spp., etc. KCM21 showed the highest activity and was effective against a wide range of target organisms. Application of KCM21 with inoculation of Pectobacterium carotovorum subsp. carotovorum on detached cabbage leaves resulted in an immune phenotype or a significant reduction in symptom development, depending on the peptide concentration. Cytotoxicity of the four hexapeptides was evaluated in mouse and human epithelial cell lines using an MTT test. The results revealed a lack of cytotoxic effects.

• 대한화장품학회지
• /
• 제28권3호
• /
• pp.41-62
• /
• 2002

여러 종류의 미백제들이 한국에서 보고되고 있으나 표준화된 유효성 protocol은 아직 확립되지 않은 실정이다. 그러므로 경제적이고 재현성있는 표준화된 유효성방법이 필요하다. 비방사선표지된 멜라닌정량법은 멜라닌형성에 대한 정량법으로 좋은 방법이 될 수 있으며 정상적인 사람의 melanocyte를 이용한 MTT assay는 세포의 proliferation을 정량하기 위한 좋은 방법에 될 수 있다.