• 제목/요약/키워드: Chemical assay

검색결과 1,069건 처리시간 0.024초

Bone Morphogenic Protein-2 (BMP-2) Immobilized Biodegradable Scaffolds for Bone Tissue Engineering

  • Kim, Sung-Eun;Rha, Hyung-Kyun;Surendran, Sibin;Han, Chang-Whan;Lee, Sang-Cheon;Choi, Hyung-Woo;Choi, Yong-Woo;Lee, Kweon-Haeng;Rhie, Jong-Won;Ahn, Sang-Tae
    • Macromolecular Research
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    • 제14권5호
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    • pp.565-572
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    • 2006
  • Recombinant human bone morphogenic protein-2 (rhBMP-2), which is known as one of the major local stimuli for osteogenic differentiation, was immobilized on the surface of hyaluronic acid (HA)-modified poly$(\varepsilon-caprolactone)$ (PCL) (HA-PCL) scaffolds to improve the attachment, proliferation, and differentiation of human bone marrow stem cells (hBMSCs) for bone tissue engineering. The rhBMP-2 proteins were directly immobilized onto the HA-modified PCL scaffolds by the chemical grafting the amine groups of proteins to carboxylic acid groups of HA. The amount of covalently bounded rhBMP-2 was measured to 1.6 pg/mg (rhBMP/HA-PCL scaffold) by using a sandwich enzyme-linked immunosorbant assay. The rhBMP-2 immobilized HA-modified-PCL scaffold exhibited the good colonization, by the newly differentiated osteoblasts, with a statistically significant increase of the rhBMP-2 release and alkaline phosphatase activity as compared with the control groups both PCL and HA-PCL scaffolds. We also found enhanced mineralization and elevated osteocalcin detection for the rhBMP-2 immobilized HA-PCL scaffolds, in vitro.

병포장 갓김치의 항산화 효과에 대한 연구 (Antioxidation Activities of Bottled Mustard Leaf Kimchi during Fermentation)

  • 김복남
    • 동아시아식생활학회지
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    • 제19권6호
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    • pp.950-957
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    • 2009
  • Mustard Leaf Kimchi (MLK) is a traditional fermented Korean vegetable food. This study was conducted to investigate the effects of part vacuum treatment on MLK packed in a glass bottle during fermentation. There have been a few previous studies that examined the chemical and microbial changes during MLK fermentation. However, the major object of this study was to investigate the antioxidative activities of vacuum treated MLK. In this study, the antioxidative activity of vacuum treated mustard leaf Kimchi (VM) and control mustard leaf Kimchi (CM) were examined. VM and CM were fermented at $5^{\circ}C$ for 8 weeks. A model system was designed to evaluate the antioxidative activity of crude chlorophylls and carotenoids (CCC) extracts from Mustard leaf Kimchi. The oxidative reaction of the linoleic acid mixture system at $30^{\circ}C$ in the dark was quantified determining the peroxide value and conjugated dienoic acid content. The effect of the CCC extracts on lipid peroxidation in a rat liver homogenate was examined. Formation of lipid peroxides was estimated by the TBA value, and the CCC extracts were found to inhibit the TBA value. Chlorophyll a and b, and carotenoids, Which are the major components in the CCC extracts of Kimchi were isolated on a DEAE-sepharose CL-6B and Sepharose CL-6B column and TLC. The effects of chlorophyll a and b, caroteins on linoleic acid autoxidation were measured by determining the peroxide value. In addition, their effects on free radical scavenging were investigated by DPPH. In this assay, chlorophyll a showed the greatest antioxidative activity followed by chlorophyll b, and carotenoids. MLK contains a sufficient content of chlorophyll a and b, and carotenoid which have strong antioxidative activities.

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Cellular-uptake Behavior of Polymer Nanoparticles into Consideration of Biosafety

  • Do, Jeong-Hoe;An, Jeong-Ho;Joun, Yong-Seung;Chung, Dong-June;Kim, Ji-Heung
    • Macromolecular Research
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    • 제16권8호
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    • pp.695-703
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    • 2008
  • Nanoparticles have tremendous potential in cancer prevention, detection and augmenting existing treatments. They can target tumors, carry imaging capability to document the presence of tumors, sense pathophysiological defects in tumor cells, deliver therapeutic genes or drugs based on the tumor characteristics, respond to external triggers to release an appropriate agent, document the tumor response, and identify the residual tumor cells. Nanoparticles < 30 nanometers in diameter show unexpected and unique properties. Furthermore, particles < 5 nanometers in size can easily penetrate cells as well as living tissues and organs. This study evaluated the safety of nano materials in a living body and the relationship between the living tissue and synthetic nano materials by examining the in-vitro cytotoxicity of poly(lactic-co-glycolic) acid (PLGA) nano-spheres and fluorescein isothiocynate(FITC)-labeled dendrimers as polymer nanoparticles. PLGA was chosen because it has been used extensively for biodegradable nanoparticles on account of its outstanding bio-compatibility and its acceptance as an FDA approved material. The dendrimer was chosen because it can carry a molecule that recognizes cancer cells, a therapeutic agent that can kill those cells, and a molecule that recognizes the signals of cell death. Cytotoxicity in L929 mouse fibroblasts was monitored using MTT assay. Microscopic observations were also carried out to observe cell growth. All assays yielded meaningful results and the PLGA nanoparticles showed less cytotoxicity than the dendrimer. These nano-particles ranged in size from 10 to 100 nm according to microscopy and spectroscopic methods.

돼지 림프구의 미소핵 형성을 지표로 방사선 생물학적 선량측정법 확립 (Establishment of micronuclus assay as biological dosimetry in pig lymphocytes after gamma-irradiation)

  • 김세라;이해준;이진희;강창모;김태환;조성기;김종춘;김성호
    • 대한수의학회지
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    • 제44권3호
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    • pp.323-327
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    • 2004
  • The purpose of the present experiment was to investigate the micronuclei(MN) frequency in cytokinesis-blocked(CB) cells after various doses of gamma-rays in pig (Landrace, male, 3-month-old) and so to contribute to the clarification of the question whether these species are suitable as a target organism in the test system. The frequencies of binucleated cells, and gamma-ray-induced MN in CB cells at several doses were measured in three donors. The peaks of binucleated lymphocyte formation(22%) were found at a concentration of 2% phytohaemagglutinin(PHA) and $4{\mu}g/ml$ Cytochalasin B(Cyt-B) in pig at 72 hours after incubation. Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors studied. When analysed by linear-quadratic model the line of best fit was $y=0.0183D+0.0124D^2+0.0133$(y = number of MN/CB cells and D=irradiation dose in Gy). In conclusion, the results demonstrate that it appears feasible to use pig as target organisms in the micronucleus test to estimate the cytogenetic damage caused by ionizing radiations or, potentially, chemical compounds.

Pyridoxatin, an Inhibitor of Gelatinase A with Cytotoxic Activity

  • Lee, Ho-Jae;Chung, Myung-Chul;Lee, Choong-Hwan;Chun, Hyo-Kon;Kim, Hwan-Mook;Kho, Yung-Hee
    • Journal of Microbiology and Biotechnology
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    • 제6권6호
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    • pp.445-450
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    • 1996
  • Gelatinase A is a member of the matrix metalloproteinases that play an important role in cancer invasion and metastasis. In the course of screening gelatinase A inhibitors from microbial sources, a fungal strain PT-262 showed a strong inhibitory activity. The strain was identified as Chaunopycnis alba on the basis of its morphological characteristics. The inhibitor was isolated from acetone extract of mycelial cake by sequential chromatographies on MCI-gel, Sephadex LH-20, and a reverse-phase HPLC column. The purified inhibitor was identified as pyridoxatin by its physico-chemical properties and spectroscopic analysis. Pyridoxatin is not a peptide analog and has cyclic hydroxamic acid moiety. It inhibited activated gelatinase A with an $IC_{50}$ value of 15.2 ${\mu}M$ using fluorescent synthetic peptide. It also had a strong cytotoxicity against human cancer cell lines in vitro. Furthermore, this compound inhibited DNA synthesis with an $IC_{50}$ value of 2.92 ${\mu}M$ in PC-3 prostate cancer cells by [$^3H$]thymidine incorporation assay.

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Quorum Quenching Bacteria Isolated from the Sludge of a Wastewater Treatment Plant and Their Application for Controlling Biofilm Formation

  • Kim, A-Leum;Park, Son-Young;Lee, Chi-Ho;Lee, Chung-Hak;Lee, Jung-Kee
    • Journal of Microbiology and Biotechnology
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    • 제24권11호
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    • pp.1574-1582
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    • 2014
  • Bacteria recognize changes in their population density by sensing the concentration of signal molecules, N-acyl-homoserine lactones (AHLs). AHL-mediated quorum sensing (QS) plays a key role in biofilm formation, so the interference of QS, referred to as quorum quenching (QQ), has received a great deal of attention. A QQ strategy can be applied to membrane bioreactors (MBRs) for advanced wastewater treatment to control biofouling. To isolate QQ bacteria that can inhibit biofilm formation, we isolated diverse AHL-degrading bacteria from a laboratory-scale MBR and sludge from real wastewater treatment plants. A total of 225 AHL-degrading bacteria were isolated from the sludge sample by enrichment culture. Afipia sp., Acinetobacter sp. and Streptococcus sp. strains produced the intracellular QQ enzyme, whereas Pseudomonas sp., Micrococcus sp. and Staphylococcus sp. produced the extracellular QQ enzyme. In case of Microbacterium sp. and Rhodococcus sp., AHL-degrading activities were detected in the whole-cell assay and Rhodococcus sp. showed AHL-degrading activity in cell-free lysate as well. There has been no report for AHL-degrading capability in the case of Streptococcus sp. and Afipia sp. strains. Finally, inhibition of biofilm formation by isolated QQ bacteria or enzymes was observed on glass slides and 96-well microtiter plates using crystal violet staining. QQ strains or enzymes not only inhibited initial biofilm development but also reduced established biofilms.

Agrobacterium tumefaciens 공동배양법을 이용한 옥수수 형질전환체 생산 (Production of Transgenic Maize (Zea mays L.) Using Agrobacterium tumefaciens-Mediated Transformation)

  • 조미애;박윤옥;김진석;박기진;민황기;유장렬;;최필선
    • Journal of Plant Biotechnology
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    • 제32권2호
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    • pp.91-95
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    • 2005
  • 옥수수 미숙배배양과 Agrobacterium tumefaciens공동배양법에 의해 형질전환체를 생산하였다. Hi II계통의 미숙배를 Ubiquitin 1 promoter-GUS유전자와 선발마커로서 nptII 유전자로 제작된 pPTN290벡터를 C58C1에 도입한 후 형질전환 균주로 사용하였다. 7개의 paromomycin저항성 배 발생캘러스를 얻었으며, GUS양성반응을 나타내는 7개의 독립적인 식물체를 얻었다. Southern분석법에 의하여 $T_1$세대 식물체로부터 nptII유전자가 안정적으로 도입되어 있음을 확인하였다.

Inhibition of TNF-α-mediated NF-κB Transcriptional Activity in HepG2 Cells by Dammarane-type Saponins from Panax ginseng Leaves

  • Song, Seok-Bean;Tung, Nguyen Huu;Quang, Tran Hong;Ngan, Nguyen Thi Thanh;Kim, Kyoon-Eon;Kim, Young-Ho
    • Journal of Ginseng Research
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    • 제36권2호
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    • pp.146-152
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    • 2012
  • Panax ginseng (PG) is a globally utilized medicinal herb. The medicinal effects of PG are primarily attributable to ginsenosides located in the root and leaf. The leaves of PG are known to be rich in various bioactive ginsenosides, and the therapeutic effects of ginseng extract and ginsenosides have been associated with immunomodulatory and anti-inflammatory activities. We examined the effect of PG leaf extract and the isolated ginsenosides, on nuclear factor (NF)-${\kappa}B$transcriptional activity and target gene expression by applying a luciferase assay and reverse transcription polymerase chain reaction in tumor necrosis factor (TNF)-${\alpha}$-treated hepatocarcinoma HepG2 cells. Air-dried PG leaf extract inhibited TNF-${\alpha}$-induced NF-${\kappa}B$transcription activity and NF-${\kappa}B$-dependent cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) gene expression more efficiently than the steamed extract. Of the 10 ginsenosides isolated from PG leaves, Rd and Km most significantly inhibited activity in a dose-dependent manner, with $IC_{50}$ values of $12.05{\pm}0.82$ and $8.84{\pm}0.99\;{\mu}M$, respectively. Furthermore, the ginsenosides Rd and Km inhibited the TNF-${\alpha}$-induced expression levels of the COX-2 and iNOS gene in HepG2 cells. Air-dried leaf extracts and their chemical components, ginsenoside Rd and Km, are involved in the suppression of TNF-${\alpha}$-induced NF-${\kappa}B$ activation and NF-${\kappa}B$-dependent iNOS and COX-2 gene expression. Consequently, air-dried leaf extract from PG, and the purified ginsenosides, have therapeutic potential as anti-inflammatory.

B16/F10 흑색 종 세포에서 오디(Morus alba) 에탄올 추출물의 멜라닌 생성 저해 작용과 항산화 활성 (Antioxidation Activity and Inhibition of Melanin Synthesis of Ethanol Extracts from Morus alba in B16/F10 Melanoma Cells)

  • 조미래;조인아;이중헌;김수관;이숙영
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 춘계학술발표회
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    • pp.63-63
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    • 2018
  • 본 연구에서는 80% 식물성 알코올을 추출 용매로 사용해 오디를 빛을 차단 후 실온에서 3일 간 추출하였다. 3회 여과한 후 최소 온도($40{\sim}60^{\circ}C$)에서 농축한 뒤 동결 건조하여 파우더 형태로 사용하였다. 오디(Morus alba)의 에탄올 추출물은 B16/F10 세포의 항산화 및 멜라닌 합성 억제 효과를 나타내었다. 멜라닌 함량과 세포 내 tyrosinase 활성을 Western blotting으로 측정 하였다. Tyrosinase와 tyrosinase-related protein (TRP) -1은 tyrosinase-related protein (TRP) -2보다 강력하게 억제되었으며, 이들 결과는 tyrosinase와 TRP-1은 흑갈색을 띠는 eumelanin의 생합성의 억제와 강한 상관관계가 있음을 보여 주었다. ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH) 처리 한 B16/F10 흑색 종 세포에서 M. alba 에탄올 추출물은 멜라닌 생성 연관 단백질의 발현 및 멜라닌 생성이 용량 의존적으로 억제 하였다. 멜라닌 함량과 세포 내 tyrosinase 활성을 Western blotting으로 측정 하였다. 또한 DPPH와 SOD를 사용하여 항산화 활성을 분석하였고 총 폴리 페놀과 총 플라보노이드 함량을 측정 하였다. MTT assay 분석을 사용하여 M. alba 에탄올 추출물의 세포 독성을 측정 하였다. B16/F10 멜라닌 생성 세포의 tyrosinase 저해 활성 및 사멸 효과가 일반적으로 효과적이었다. 따라서 M. alba 에탄올 추출물은 항산화 및 미백 효과를 나타내며, 기능성 화장품의 천연 성분으로서 우수한 것으로 여겨진다.

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개오가피의 성분 및 항암효과 (Chemical Components of Acanthopanax divaricatus and Anticancer Effect in Leaves)

  • 육창수;노영수;서성훈;임재윤;한덕용
    • 약학회지
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    • 제40권3호
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    • pp.251-261
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    • 1996
  • Acanthopanax divaricatus Seem. is a medicinal plant growing widely through out Korea, Japan and China. The plant material of Acanthopanax spp. is used as analgesic , tonic, sedative drug as well as for the treatment of hypertension, rheumatism and diabetes. From the stem barks and root barks of A. divaricatus, diterpenoid compound was isolated and identified as pamaric acid ($C_{20}H_{30}O_2,\;mp\;164^{\circ}C$), lignan compounds were isolated and identified as d-sesamin ($C_{20}H_{18}O_6,\;mp\;123{\sim}124^{\circ}C$), eletheroside E ($C_{34}H_{46}O_{18},\;mp\;257{\sim}259^{\circ}C$), three sterol compounds were identified as ${\beta}$-sitosterol, campesterol, stigmasterol, and six fatty acid compounds were identified as stearic acid, palmitic acid, oleic acid, linolenic acid, arachidonic acid and behenic acid. And also leaves of A. divaricatus, chiisanoside were identified, one of secotriterpenoidal compound(white amorphorous powder crystal, mp $228^{\circ}C$). Anticancer activity and nephrotoxicity were tested by MTT assay. Anticancer effect of chiisanoside was much lower than that of cisplatin.

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