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        검색결과 11

        2.
        2016.03 구독 인증기관 무료, 개인회원 유료
        Effectiveness of transgene transfer into genome is crucially concerned in mass production of the bio-pharmaceuticals using genetically modified transgenic animals as a bioreactor. Recently, the mammary gland has been considered as a potential bioreactor for the mass production of the bio-pharmaceuticals, which appears to be capable of appropriate post-translational modifications of recombinant proteins. The mammary gland tissue specific vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals. In this study, to minimize physiological disturbance caused by constitutive over-expression of the exogenous gene, we constructed new retrovirus vector system designed for mammary gland-specific expression of the hEPO gene. Using piggyBac vector system, we designed to express hEPO gene under the control of mammary gland tissue specific and lactogenic hormonal inducible goat β-casein or mouse Whey Acidic Protein (mWAP) promoter. Inducible expression of the hEPO gene was confirmed using RT-PCR and ELISA in the mouse mammary gland cells treated with lactogenic hormone. We expect the vector system may optimize production efficiency of transgenic animal and reduce the risk of global expression of transgene.
        4,000원
        4.
        2016.10 서비스 종료(열람 제한)
        Background : Plants are the rich source of antioxidants, which plays a very important role in maintaining human health. Their antioxidant property protects cells of different organs of human beings against free radicals and free radical mediated diseases. Even though, there is lack of knowledge on the antioxidant effect of lutein present in plants. In the present study, lutein was isolated from the GreenTea leaves (Camellia sinensis) which is used as a dietary source. Methods and Results : The procedure adopted for the isolation and purification of lutein using acetone extraction and preparative high performance liquid chromatography (HPLC) is simple and less time consuming. Free radicals scavenging activity of isolated lutein from acetone extract of GreenTea was assessed by DPPH radical scavenging assay and reducing power. The isolated lutein scavenged 79% of DPPH radicals at 20 ㎍/㎖ and two fold lower concentration compared to the standard antioxidants (α-tocopherol). No significant differences were found between the reducing power of the lutein and BHT when their concentrations were high. However, significant differences were observed at relatively low concentrations, the reducing power of lutein was isolated from the GreenTea leaves was stronger than those of their acetone extract and standard antioxidants (BHA). Both electron spin resonance (ESR) and in vitro assay confirmed that lutein was isolated from the GreenTea leaves, exhibited a greater capacity for scavenging superoxide (O2 •-) and hydroxyl (OH •) radicals than standard antioxidants β-carotene and α-tocopherol respectively. Conclusion : The results proven that lutein isolated from GreenTea leaves has an efficient antioxidant ability, it could serve as an antioxidant to scavenge reactive oxygen species.
        5.
        2016.05 서비스 종료(열람 제한)
        Background : Indigenous plant in Jeju island, Sasa quelpaertensis Nakai, belongs to the Bambusoideae and inhabit around Mt. Halla. According to the ancient book such as Dongui Bogam, Sasa quelpaertensis Nakai have been known to possess the antidiabetic, anti-inflammatory, and anti-diuresis effect. However, because of gradual upturning temperature, Sasa quelpaertensis Nakai was spread out to wider area and intrude the habitat that other plant species are growing. Recently, although the study to seek effective use of Sasa quelpaertensis Nakai, the investigation about functional properties has not been taken place enough. Methods and Results : To assess the inhibitory activity of melanin synthesis, we employ the tyrosine as substrate and measure the formation of dopaquione at 490 nm. Firstly, 0.1 mM potassium phosphate buffer and tyrosinase were mixed and incubated at 37℃. After incubating at 37℃, the absorbance rate was measured at 490 nm. The value was compared with positive control, arbutin, and calculated with the rate between sample and control value. Previously, formononetin, glabrene, glabridin, glabrol, artocarbene, dihydromoriin are known as effective substances for whitening. Moreover, the arbutin, which was separated from Arctostaphylos uva-ursi (L.) Sprengel, are widely used in cosmetic field. Arbutin inhibits tyrosinase and tyrosine synthesis, which induce blackish pigmentation. Practically, the Sasa quelpaertensis Nakai leaf ethanol extract depend on different solvent condition, whole extracts showed stronger inhibition than arbutin. Especially, 60% ethanol extract exhibited twice higher tyrosinase inhibitory activity than arbutin, whereas least inhibitory activity was seen in 20% ethanol extract. Conclusion : In this study, a attempt was made to investigate the tyrosinase inhibitory activity of Sasa quelpaertensis Nakai leaves extracted by different solvent condition. In the results, each extracts was prior to arbutin. Yet, 20% ethanol extract was lowest, but on the one hand, 60% ethanol extract demonstrated the highest tyrosinase inhibitory activity.
        6.
        2015.09 서비스 종료(열람 제한)
        Endocrine disruptors are exogenous chemicals that their endocrine disrupting effects mediated by androgenic signaling plays crucial roles in the control of development and several androgen-related diseases. However, there are no authorized in vitro screening and testing methods to evaluation of (anti-)androgenic activity. To find out a better in vitro cell line model, we have previously reported that 22Rv1 cells, a human prostate cancer cells contained functional Androgen Receptor (AR), might be an appropriate model for the evaluation of (anti-)androgenic endocrine disruptors. Based on this result, we developed a stable 22Rv1/mouse mammary tumor virus (MMTV) cell line to test AR-mediated transcriptional activation (TA). Using 22Rv1/MMTV cells, we established the test protocol and optimized the testing condition for AR-TA assay. In this study, we performed the inter-validation assay by four different laboratories to evaluate the 20 coded chemicals which were selected from the ICCVAM list (ICCVAM, 2003) or academic articles that exhibited exact (anti-) androgenic activity. The statistical analysis of the results of the inter-laboratory validation study revealed that there was reproducibility between the four participating laboratories. In conclusion, 22Rv1/MMTV AR-TA assay might be a quick and relatively inexpensive method, which can be used to screen large numbers of chemicals for their potential to activate or inhibit AR-mediated gene transcription. Furthermore, it will provide mechanistic data relevant to understanding adverse reactions observed in intact organisms.
        7.
        2010.03 KCI 등재 서비스 종료(열람 제한)
        기존의 유기계 자외선차단제는 피부에 대한 자극과 투과의 문제, 무기계 자외선차단제는 백탁현상 등 몇 가지 문제점이 알려져 있다. 최근에 보다 효과적인 자외선차단제를 개발하기 위한 연구가 진행되고 있으며, 그 중의 하나가 유기/무기 복합구조의 자외선차단제에 대한 연구이다. 본 연구진은 새로운 자외선차단제인 메톡시신나미도프로필폴리실세스퀴옥산의 제조와 그 효과에 대해 보고한 바 있다. 특별히, 본 연구는 신규 자외선차단제의 화학적 구조에 대한 정성적인 분석과 향상된 자외선차단 효과 및 화장료 제형에 대한 적용성을 평가하였다. 자외선차단제의 구조분석은 TGA, solid state NMR, 원소분석을 이용하여 평가하였으며, 자외선차단지수는 5 wt%를 포함하는 제형을 평가하였을 때, 6.0 정도의 수치를 보였다. 또한, 기존의 유기 및 무기 자외선차단제와 혼합적용 시, 자외선차단효과에 대한 우수한 시너지 효과를 나타내었으며, W/S 유형의 화장료 제형에서 우수한 적용성을 보였다.
        8.
        2008.09 KCI 등재 서비스 종료(열람 제한)
        미백제를 선발하기 위해 주로 사용하는 현재의 방법은 in vitro 타이로시네이즈 활성 및 항산화능을 측정하는 것이다. 이 결과에 기초하여 다음 단계인 멜라노사이트에서의 멜라닌 생성량을 측정한다. 세포 내의 멜라닌 생성량 측정법은 시간, 인력 및 숙련도가 요구된다. 따라서 초기 선발 방법의 신뢰성이 중요하다. 200개 중국시료 중 측정범위 내에서 세포독성이 없는 34개를 대상으로 세포 내 멜라닌량, 타이로시네이즈 활성, 항산화능의 상관관계를 조사하였다. 조사결과 직선의 상관관계를 확인할 수 없었다. 이 결과는 현재 선발방법의 한계 및 새로운 방법이 필요함을 보여주었다.
        9.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        백련 잎의 소비확대를 위한 기초자료 확보측면에서 2007년 8월에 ‘가람’, ‘초의’, ‘백화건련’, ‘승달’ 백련의 잎을 수확하여 열수와 에탄올 추출물의 생리활성 효과를 조사하였다. 총 페놀함량은 열수 추출물의 경우 ‘초의’ 백련에서 78.3㎍·mL-1로 가장 많았고, 에탄올 추출물은 ‘백화건련’에서 146.8㎍·mL-1로 가장 많았다. 전자공여능은 추출물의 농도가 2,000ppm일 때 ‘승달’의 열수 추출물 및 에탄올 추출물에서 각각 83.3%와 94.0%로 가장 높았다. 총 플라보노이드 함량은 에탄올 추출물에서 높게 나타나 63.6㎍·mL-1(‘승달’)-92.2㎍·mL-1(‘초의’)를 나타낸 반면에 열수 추출물은 28.8㎍·mL-1(‘초의’) 이하를 나타내었다. 아질산염 소거는 추출물의 농도가 2,000ppm일 때 열수 추출물은 ‘초의’ 에서 69.2%로 가장 높게 나타났으며, 에탄올 추출물에서는 ‘백화건련’에서 80.7%로 가장 높게 나타났다. Tyrosinase 활성 저해 효과는 백련의 종류 및 용매에 관계없이 거의 나타나지 않았다. 항균활성은 에탄올 추출물에서 다소 높게 나타났는데, 저해환의 직경은 전반적으로 8.3-11.2mm를 나타냈다.
        10.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        Antioxidant activity, total phenolics level and cytotoxicity of the methanol extracts from the young sprouts of 5 Korean woody salad plants were determined. Methanol extracts of Kalopanax pictus had the highest DPPH radical scavenging activity, with an IC50 value of 23.5mg 100g-1, and followed by Valeriana fauriei(43.1mg 100g-1), and Morus alba(〉100mg 100g-1). Total phenolic content showed the highest amount in methanol extracts from Kalopanax pictus(23.7mg 100g-1), and followed by Valeriana fauriei(22.7mg 100g-1), Aralia elata(16.8mg 100g-1) and Morus alba(14.2mg 100g-1). In a MTT assay, methanol extracts of Aralia elata with IC50 values of 151.0 and 140.7μg mL-1 showed the most potent cytotoxicity on Calu-6 and MCF-7, respectively. On the other hand, methanol extracts of Kalopanax pictus(IC50=96.5μg mL-1) showed the highest activity against HCT-116, and followed by those of Aralia elata(123.3μg mL-1), and Actinidia arguta(162.0μg mL-1). Total phenolic content of the tested plant extracts was correlated with the DPPH radical scavenging activity, suggesting the phenolic compounds may contribute to the antioxidant properties of Korean salad plants.