유한요소해석을 통한 단순교에 대한 최대 충격계수 응답스펙트럼 검증

유민관 ( Ryu Minkwan ),하쉬라몬이브라힘 ( Hashlamon Ibrahim ),박경훈 ( Park Kyung-hoon ),노화성 ( Roh Hwasung ) 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.19 No.2

마황(Ephedra sinica) 에탄올추출물의 항산화 효과 및 각질세포 보호효과

유민정 ( Min Jeong Ryu ),모정희 ( Jeong Hee Mo ) 한국미용학회 2014 한국미용학회지 Vol.20 No.4

This study induced oxidative stress in human HaCat cells to test the antioxidativity of Ephedra sinica ethanol extract and its protectiveeffects in order to develop safer and more outstanding skin care materials and products from natural sources. Ephedra sinica ethanol extract has a polyphenol content of 175.5±0.66 μg/ml, flavonoid content of 56.91±2.15 μg/ml. As a result of measuring the DPPH radical absorption capacity, IC50 was 27.51 μg/ml, which was higher than that for BHT, a synthetic antioxidant, at 105.1 μg/ml, and it was above90% at 400 μg/ml, which is similar to that of vitamin C. With respect to the cell survival rates, when the extract was applied to HaCaTcells according to each concentration, cytotoxity was observed depending on the concentration. When the cell survival rate of the control group was considered as 100%, the test group which did not have any pre-treatment showed a cell survival rate of 49.5%. When the cell was stimulated with H2O2, ROS was removed by 81.5%, 76.0%, and 66.2%, which indicates its removal effect depending on concentration. The protective effect of the extract on HaCat cells from H2O2, rotenone and paraquat was checked and observed depending on concentration. Therefore, as this study discovered the antioxidativity of Ephedra sinica ethanol extract, its ROS removal from HaCat cells and the protective effect from oxidative stress, it is suggested that it will restore oxidative damage in skin.

연구논문 : 오이풀 추출물의 비듬균에 대한 항진균 효과 및 RAW 264.7 세포에서의 항염증 효과

유민정 ( Min Jeong Ryu ),임요섭 ( Yo Sup Rim ),최다인 ( Da In Choi ),이숙영 ( Sook Young Lee ) 한국미용학회 2011 한국미용학회지 Vol.17 No.2

In this study, we analyzed the anti-fungal activity against Malassezia furfur, anti-oxidative activity and anti-inflammatory activity of Sanguisorba officinalis extracts. The ethanol extract of S. officinalis was sequentially fractionated with hexane, ethyl acetate, butanol and water. The cell viability was measured by MTT assay. Nitric oxide (NO) production was measured by Griess reagent assay. Anti-fungal activity was examined by paper disc method. The total phenolic contents and flavonoid contents were determined in all the samples, in the following order: ethanol > ethyl acetate > butanol > water > n-hexane. The ethyl acetate fraction showed high inhibition activity to DPPH scavenging radical activity at 500 μg/mL (96%) and more strongly inhibited NO productions compared with other fractions. Also, the ethyl acetate fraction showed the highest anti-fungal activity. According to the results above, it was summarized that the ethyl acetate fraction of S. officinalis have anti-oxidative, anti-fungal and anti-inflammatory activity in M. furfur or macrophage. It would be proposed that ethyl acetate fraction of S. officinalis can become a new cosmetic materials.

BSR 성능 향상을 위한 인사이드벨트 웨더스트립 장착구조 개발

유민한(Ryu, Min Han),장기수,이상현(Lee, Sang Hyun),이재승(Lee, Jae Seung),최형식 한국자동차공학회 2017 한국자동차공학회 학술대회 및 전시회 Vol.2017 No.11

HKMC producted cars have field claims when door glass up&down and press uprtrim cause noise. That noise is chronic customer complaints. So I need improve that noise claims. Insidebelt weatherstrip mounting structure is important element of the noise. This research paper purpose is improve noise between insidebelt and uprtrim. This research paper will analisis noise reasons and propose improved mounting structure and material about insidebelt. The new proposed mounting structure can be mass product.

노루발풀 추출물의 in vitro에서의 항산화, 항염증 및 항히스타민 활성

유민정 ( Min Jeong Ryu ),이숙영 ( Sook Young Lee ),차영주 ( Young Ju Cha ) 한국미용학회 2012 한국미용학회지 Vol.18 No.3

Pyrola japonica in Chinese traditional medicine have been used as tonics, sedatives, analgesics against rheumatoid arthritis, hemostatics, and recently isolated anti-inflammatory agents from whole plants. We have investigated antioxidant effect of P. japonica extract using DPPH raidcal scavenging test, total polyphenol and flavonoid content assay, nitrite(NO) scavenging test in cell-free system. Also, antihistamine activity by β-hexosaminidase assay and anti-inflammatory effect by inhibition rate of NO production in RAW 264.7 cell was evaluated. Skin irritation test of the extracts was evaluated in accordance with the guidelines of patch test. Plant extracts were prepared by ethanol extraction method. DPPH raidcal scavenging activity of ethanol extract of P. japonica. was the highest in 400 μg/mL as 88.62±1.51% and increased in a concentration-dependent manner. Total polyphenol and total flavonoid content of the extract was 107.5±0.03 μg/mL and 50±0.01 μg/mL, respectively. The NO scavenging activity in cell-free system was the highest in 800 μg/mL as 42.13±2.72% and it was also increased in a concentration-dependent manner. P. japonica extract will not significantly affect cell viability of RBL-2H3 cell for β-hexosaminidase assay and RAW 264.7 cell for NO content assay at the concentration of 5~50 μg/mL. The inhibition of β-hexosaminidase release was respectively indicated as 15.5, 43.0, 56.4, 67.9% in 5, 10, 20, 50 μg/mL of extract and it was increased in a concentration-dependent manner. Anti-inflammatory activity by NO content measurement in RAW cell was the highest in 50 μg/mL (NO content of 5.7±0.5 μM/mL) of P. japonica extract and additionally it was concentration-dependent. The patch application performed in order to determine dermal irritation of the extract showed result of no dermal reaction that is safety on skin. These results suggest that P. japonica extract can use as a resource of natural cosmetic material for anti-oxidant, anti-inflammatory, anti-itching gradients, and also safety on skin.

유아의 정서지능과 어머니의 양육태도와의 관계

유민임 ( Min Im Ryu ) 미래유아교육학회 2005 미래유아교육학회지 Vol.12 No.4

6종의 약용식물 추출물의 비듬균(Malassezia furfur)에 대한 증식억제 및 항산화 효과

유민정 ( Min Jeong Ryu ),이숙영 ( Sook Young Lee ),박열 ( Yeol Park ),양영기 ( Young Ki Yang ) 한국미용학회 2010 한국미용학회지 Vol.16 No.1

This study examined to screen the cosmetic materials with the antioxidative and antifungal activites of the crude extracts from 6 spp. medicinal plants. The extracts were prepared by ethanol extraction method. The antioxidant activities of extracts was used the method of DPPH radical and nitrite scavenging assay, total polyphenolics and flavonoid contents. Their antifungal activity against Malassezia furfur examined through the paper disc agar diffusion assay. Among the 6 plants tested, the extracts of Forsythia viridissima and Echinops setifer displayed a strong antifungal effect against M. furfur. The DPPH radical scavenging activity of the aerial part of Houttuyni cordata showed a considerable IC50 value (89.81 ㎍/㎖) and it was higher than that of BHT standard oxidant. The contents of total phenolics (292.36 ㎍/㎖) and flavonoids (208.20 ㎍/㎖) in the Houttuynia cordata aerial part were higher than the other medicinal plants. The nitrite scavenging ability was high in the extract of Forsythia viridissima fruit. These results suggested that medicinal plants could be the potential source of anti-dandruff agent.

만성 신부전 환자에서 Methylenetetrahydrofolate reductase (MTHFR)유전자 다형성이 고호모시스테인혈증과 말초혈관 동맥경화에 미치는 영향: 만성 신부전 환자에서 MTHFR 유전자 다형성의 의미 MTHFR 유전자 다형성과 말초혈관 동맥경화의 연관성

류정화 ( Jung Hwa Ryu ),강보영 ( Bo Young Kang ),유민아 ( Min A Yu ),류동열 ( Dong Ryeol Ryu ),김승정 ( Seung Jung Kim ),강덕희 ( Duk Hee Kang ),최규복 ( Kyu Bok Choi ),윤견일 ( Kyun Il Yoon ) 대한신장학회 2007 Kidney Research and Clinical Practice Vol.26 No.2

목적: 최근에 신부전 환자들의 심혈관 질환의 발생은 혈중 호모시스테인 농도와 관련이 없고 5, 10-Methylenetetrahydrofolate reductase (MTHFR) C677T 유전자 다형성과 관련이 있다는 보고가 나오고 있다. MTHFR 유전자 다형성이 혈중 호모시스테인의 농도를 증가시킨다는 기존의 의미 외에, 그 자체가 죽상동맥경화증이나 심혈관계 질환의 독립적인 위험인자가 될지는 매우 흥미로운 사실이다. 따라서 본 연구에서는 만성 신부전 환자에서 MTHFR 유전자 다형성을 조사하여 혈장 호모시스테인 농도, 말초혈관의 동맥경화증 등과의 연관성을 살펴보고자 하였다. 방법: 본 연구는 이화의료원에서 2004년 7월에서 2005년 6월까지 신장내과에 입원한 중등도 이상 (GFR 30 mL/min 미만)의 만성 신부전 환자 128명의 MTHFR 유전자형을 standard PCR/restriction fragment length polymorphism를 이용하여 분석 하였고, Doppler 혈압측정기를 이용하여 ankle brachial index (ABI)를 측정하였다. 환자들의 혈액을 채취하여 호모시스테인, 엽산, 비타민 B12 등의 농도를 측정하였다. 대조군은 종합검진을 위해 내원한 사람들 중 신장 기능에 이상이 없는 170명을 대상으로 혈액 채취를 하여 MTHFR 유전자 다형성을 환자군과 같은 방법으로 분석하였다. 결과: 1) 한국인 만성 신부전 환자에서 MTHFR 677유 전자형의 분포는 CC (33.6%), CT (47.7%), TT (18.7%)로 나타났고 이는 신기능이 정상인 군과 차이가 없었고, TT형에서 CC형에 비해 혈장 호모시스테인 농도가 유의하게 높았다 (p<0.05). 2) 만성 신부전환자의 MTHFR 1298 유전자형의 분포는 AA (63.78%), AC (33.07%), CC (3.15%)로 대조군과 차이가 없었고, 유전자형에 따른 혈장 호모시스테인 농도의 차이가 없었다 (p=0.2063). 3) ABI 수치와 혈장 호모시스테인 농도간에는 유의한 상관관계가 없었다. 4) 혈장 호모시스테인 농도는 비타민 B12, 엽산 농도와 각각 음의 상관관계가 있었다 (각각 r=-0.305, r=-0.293, p<0.001). 5) 전체 환자군에서 ABI에 영향을 주는 인자로 볼 수 있는 당뇨, 고혈압, 55세 이상, 흡연력, 심혈관 질환, 투석 기간, 투석 방법, 혈장 호모시스테인 농도를 보정하여 로지스틱스 회귀분석한 결과 MTHFR 677 유전자형이 TT인 군에서 말초 혈관질환을 의심할 수 있는 ABI<0.9일 위험도는 CC군에 비해 위험도가 3.226 이었으나 통계적으로는 유의한 차이가 없었다 (p=0.1435). 6) 투석환자군에서 ABI에 영향을 주는 인자를 분석하였을 때 단변량 회귀분석 결과 MTHFR 677 TT 유전형이 ABI와 음의 상관 관계를 보이는 경향이었으나 (p=0.053), 다변량 회귀분석에서 통계적으로 유의한 의미는 없었다. 결론: 한국인에서 만성 신부전 환자와 대조군 사이에 MTHFR 유전자 다형성에는 차이가 없었다. MTHFR 677 TT 유전자 변형이 고호모시스테인혈증과 연관이 있었으나 이 두 가지 모두 말초혈관 질환의 위험성과는 통계적으로 유의한 관련이 없었다. Purpose: Recently, many studies have investigated that Methylenetetrahydrofolate Reductase (MTHFR) polymorphism may be not a only cause for hyperhomocysteinemia, but also an independent risk factor for cardiovascular disease or atherosclerosis in renal failure patients. In this study, we analyzed MTHFR polymorphisms in chronic renal failure (CRF) patients, and investigated relationship between MTHFR polymorphism and peripheral atherosclerosis. Methods: One hundred twenty eight CRF patients with GFR<30 mL/min were enrolled. We analyzed their MTHFR polymorphism by standard PCR/restriction fragment length polymorphism and measured their ankle brachial index (ABI) using blood pressure cuff and Doppler stethoscope. Plasma homocysteine, vitamin B12, and folic acid levels were measured. 170 healthy peoples were enrolled for control group. Results: The distribution of MTHFR 677 polymorphism of CRF patients was as follows: CC genotype, 33.6%; CT, 47.7% and TT 18.7%. Plasma homocysteine concentration was higher in TT group than in CC group (p<0.05). The distribution of MTHFR 1298 polymorphism of CRF patients was as follows: AA type, 63.78%; AC, 33.07% and CC 18.7%. The distributions of MTHFR polymorphisms in control group were not different from patients group, respectively. There was no definite correlation between ABI and plasma homocysteine concentration. A trend of lower ABI in TT type compared with CC type within CRP patients group, but no statistical significance was shown. Conclusions: No difference of the distribution of MTHFR polymorphism was noted between CRF patients and healthy population. In CRF patients, MTHFR C677T mutation was closely associated with hyperhomocysteinemia, but both did not significantly influence to peripheral arterial disease.

당뇨 백서에서 p38 Mitogen-Activated Protein Kinase 억제제 (FR167653)가 세극막 관련 단백의 발현에 미치는 영향

류동열 ( Dong Ryeol Ryu ),유태현 ( Tae Hyun Yoo ),정동섭 ( Dong Sub Jung ),곽승재 ( Seung Jae Kwak ),박제현 ( Je Hyun Park ),이순하 ( Sun Ha Lee ),이금희 ( Jin Ji Lee ),류정화 ( Jung Hwa Ryu ),유민아 ( Min A Yu ),김승정 ( Seung Ju 대한신장학회 2008 Kidney Research and Clinical Practice Vol.27 No.3

목적: 본 연구에서는 실험적 당뇨 백서에서 p38 MAPK 억제재가 단백뇨 발생 및 세극막 관련 단백의 발현 변화에 미치는 영향을 알아보고자 하였다. 방법: Sprague-Dawley 백서 32마리를 대상으로, 16마리는 streptozotocin (65 mg/kg)으로 당뇨를 유발시켰으며 (DM군), 16마리는 위약을 투여하였다 (C군). 각 군에서 8마리는 p38 MAPK 억제제인 FR167653을 5 mg/kg의 용량으로 6주간 매일 근주하였다 (C+FR,DM+FR). 당뇨 유발 6주 후 24시간 소변을 수집한 다음 희생시켜 신장을 적출한 후 사구체를 분리하였다. 24시간 뇨알부민 배설량은 ELISA로 측정하였으며, 사구체 내 nephrin, P-cadherin, 그리고 ZO-1의 mRNA와 단백 발현은 각각 real-time PCR과 Western blot으로 분석하였다. 결과: 당뇨 유발 6주 후 24시간 뇨알부민 배설량은 C군 (0.29±0.04 mg/day)파 C+FR군 (0.32±0.04 mg/day)에 비하여 DM군 (1.09±0.17 mg/day, p<0.05)에서 유의하게 증가되었으며, 이러한 증가는 FR167653 투여로 의미있게 억제되었다 (0.38±0.05 mg/day, p<0.05). 세극막 관련 단백 중 nephrin mRNA 및 단백 발현은 DM군에서 C군에 비하여 각각 1.9배, 1.6배 증가되었으며, 이러한 증가는 FR167653 투여로 각각 74%, 89% 억제되었다 (p<0.05). 반면에, FR167653은 DM군에서 발현이 감소된 P-cadherin과 발현이 증가된 ZO-1에 의의있는 영향을 미치지 않았다. 결론: 이상의 결과로, FR167653은 당뇨 백서에서 p38 MAPK 활성화를 효과적으로 억제하였고, 뇨알부민 배설을 유의하게 감소시켰으며, 이러한 효과는 nephrin의 발현 변화의 호전과 관련이 있을 것으로 생각된다. Purpose: This study was undertaken to investigate the effect of a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor, FR167653, on urinary albumin excretion and on the expression of slit diaphragm-associated proteins in diabetic rats. Methods: Thirty-two Sprague-Dawley rats were injected with diluent [control (C), N=16] or streptozotocin intraperitoneally (DM, N=16). Eight rats from each group were treated with 5 mg/kg/day FR167653 (C+FR, DM+FR) for 6 weeks. At the time of sacrifice, 24-hour urinary albumin excretion was determined by ELISA. Glomerular nephrin, P-cadherin, and ZO-1 mRNA and protein expression were determined by real-time PCR and Western blot, respectively, with sieved glomeruli. Results: Urinary albumin excretion was significantly higher in DM compared to C rats, and this increase in albuminuria was significantly inhibited by the administration of FR167653 in DM rats. Glomerular phospho-p38 MAPK protein expression was significantly increased in DM rats compared to C rats, and FR167653 treatment significantly attenuated the increase in phospho-p38 MAPK expression in DM glomeruli. Nephrin mRNA and protein expression were higher in 6-week DM compared to C glomeruli, and these increases were significantly abrogated with FR167653 treatment in DM rats. In contrast, FR167653 had no effects on the decrease in P-cadherin expression and the increase in ZO-1 expression observed in DM glomeruli.

혈액투석 환자에서 혈관내피세포 기능이상과 관련된 인자들에 관한 연구

류정화 ( Jung Hwa Ryu ),유민아 ( Min A Yu ),류동열 ( Dong Ryeol Ryu ),김승정 ( Seung Jung Kim ),최규복 ( Kyu Bok Choi ),윤견일 ( Kyun Il Yoon ),강덕희 ( Duk Hee Kang ),편욱범 ( Wook Bum Pyun ),신길자 ( Gil Ja Shin ) 대한신장학회 2008 Kidney Research and Clinical Practice Vol.27 No.2

목적: 동맥경화성 심혈관계 질환은 아직도 투석 환자에서 사망의 가장 흔한 원인이다. 혈관내피세포의 기능이상은 동맥경화증 발생의 가장 초기 단계에 발생하는 중요한 과정으로, 비가역적인 변화인 동맥경화증과는 달리 회복 가능한 가역적인 변화이므로, 이 단계에서의 조기 진단과 치료가 가능하다면 환자의 예후 향상에 크게 기여할 수 있을 것이다. 따라서, 본 연구에서는 혈액투석 환자의 혈관내피세포 및 평활근세포의 기능을 조사하고 심혈관계 질환의 발생과 예후 결정에 중요한 인자인 전신염증반응의 지표, 환자의 영양 상태 및 기타 생화학적 지표와의 상관관계를 조사하였다. 방법: 임상적으로 안정된 혈액투석 환자 37명 (평균연령 51.8세, 평균투석기간 37.9개월)와 11명의 건강 대조군, 24명의 고혈압 대조군에서 상완동맥 도플러 초음파를 이용하여 혈관내피세포 기능을 측정하였다. 내피세포 의존성 혈관확장능 (FMD), 니트로글리세린을 설하로 투여한 후의 내피세포 비의존성 혈관확장능 (EIV), 최대반응시간 (PT) 등의 지표를 측정하고, 허혈성 심질환 (IHD)의 이환 여부, 환자의 영양 상태, hsCRP 농도 및 다른 생화학적 지표와의 상관관계를 조사하였다. 결과: 1. 혈액투석 환자의 FMD와 EIV는 건강 대조군에 비하여 감소되어 있었고, 각 반응의 PT는 두 대조군에 비해 지연되어 있었다. 고혈압 대조군에서는 FMD만 감소되어 있었고 EIV는 정상 대조군과 유사하였다. 2. FMD와 EIV는 혈중 hsCRP 농도와 각각 의미 있는 음의 상관관계가 있었으나, 연령, 투석기간, RAS 차단제의 복용 여부, 알부민, 프리알부민, 총콜레스테롤, 중성지방, 호모시스테인 농도와는 상관관계가 없었다. 3. 투석 환자 중 IHD가 있는 환자가 IHD가 없는 환자에 비하여 평균투석기간이 길었고, SGA에 의해 평가된 영양실조 환자가 많았다. hsCRP의 농도는 IHD가 있는 환자에서 증가되어 있었다 (중앙값: 1.43 vs. 0.15 mg/dL, p<0.05). IHD가 있는 환자에서 FMD (4.1±2.5 vs. 6.4±2.6%, p<0.05)와 EIV (8.7±4.1 vs. 13.8±7.2%, p<0.05)가 유의하게 감소되어 있었다. 결론: 혈액투석 환자에서 환자의 전신염증반응은 혈관내 피세포와 평활근세포의 기능 결정에 중요한 역할을 할 것으로 생각된다. CRP 농도의 증가가 전신염증반응 존재의 간접적인 지표인지 또는 혈관 기능이상에 직접적으로 작용하는지의 여부와 그 기전에 대해서는 향후 전향적인 연구와 in vitro 실험이 필요할 것으로 사료된다. Purpose: Endothelial dysfunction is an event in the atherosclerotic process usually considered reversible at its early stage. Early detection, therefor, may improve the prognosis in the cardiovascular disease. The aim of this study was to investigate the vascular function in hemodialysis (HD) patients and to explore its relation to other various parameters with a specific emphasis on systemic inflammatory reaction (SIR), nutritional status and the presence of ischemic heart disease (IHD). Methods: Flow-mediated endothelium-dependent vasodilatation (FMD) was measured, using Doppler sonogram, in 37 stable HD patients, 11 healthy people and 24 hypertensive controls. Nitroglycerineinduced endothelium-independent vasodilatation (EIV) and peak reaction time (PT) of each FMD and EIV were also measured. Results: FMD in HD patients was decreased compared to healthy group whereas it was comparable in HD patients and hypertensive control. EIV in HD patients was significantly decreased compared to healthy and hypertensive controls. PT of each FMD and EIV was significantly delayed in HD patients. Each FMD and EIV showed a negative correlation with serum hsCRP level, but no significant correlations of FMD with other parameters were noted. Both FMD and EIV were further decreased in HD patients with IHD than non-IHD group. Conclusion: Our study confirmed a characteristic pattern of vascular dysfunction in HD patients: the impaired endothelial and smooth muscle function with a delayed reaction time. Importantly, SIR was one of the important factors determining vascular dysfunction in HD patients. Further studies will be necessary to define the causative role of SIR on endothelial dysfunction and the effect of inflammation-modulating therapy.