• Molecules and Cells
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• 제20권2호
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• pp.263-270
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• 2005

Transactivation of EGF-receptor (EGFR) by G-protein coupled receptors (GPCRs) is emerging as an important pathway in cell proliferation, which plays a crucial role in the development of atherosclerotic lesion. Angiotensin II (Ang II) has been identified to have a major role in the formation of atherosclerotic lesions, although the underlying mechanisms remain largely unclear. We hypothesize that Ang II promotes the proliferation and migration of smooth muscle cells through the release of heparin-binding epidermal growth factor like growth factor (HB-EGF), transactivation of EGFR and activation of Akt and Erk 1/2, with matrix metalloproteases (MMPs) playing a dispensable role. Primary rat aortic smooth muscle cells were used in this study. Smooth muscle cells rendered quiescent by serum deprivation for 12 h were treated with Ang II (100 nM) in the presence of either GM6001 ($20{\mu}M$), a specific inhibitor of MMPs or AG1478 ($10{\mu}M$), an inhibitor of EGFR. The levels of phosphorylation of EGFR, Akt and Erk 1/2 were assessed in the cell lysates. Inhibition of MMPs by GM6001 significantly attenuated Ang II-stimulated phosphorylation of EGFR, suggesting that MMPs may be involved in the transactivation of EGFR by Ang II receptor. Furthermore Ang II-stimulated proliferation and migration of smooth muscle cells were significantly blunted by inhibiting MMPs and EGFR and applying HB-EGF neutralization antibody, indicating that MMPs, HB-EGF and EGFR activation is necessary for Ang-II stimulated migration and proliferation of smooth muscle cells. Our results suggest that inhibition of MMPs may represent one of the strategies to counter the mitogenic and motogenic effects of Ang II on smooth muscle cells and thereby prevent the formation and development of atherosclerotic lesions.

• Clinical and Experimental Pediatrics
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• 제48권6호
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• pp.580-587
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• 2005

New evidence is emerging that airway smooth muscle(ASM) may act as an immunomodulatory cell by providing pro-inflammatory cytokines and chemokines, polypeptide growth factors, extracellular matrix proteins, cell adhesion receptors and co-stimulatory molecules. ASM can promote the formation of the interstitial extracellular matrix, and potentially contribute to the alterations within the extracellular matrix in asthma. In addition, extracellular matrix components can alter the proliferative, survival, and cytoskeletal synthetic function of ASM cells through integrin-directed signaling. Increased ASM mass is one of the most important features of the airway wall remodeling process in asthma. Three different mechanisms may contribute to the increased ASM mass : cell proliferation, increased migration and decreased rate of apoptosis. The major signaling pathways of cell proliferation activated by ASM mitogens are those dependent on extracellular signal-regulated kinase and phosphoinositide 3'-kinase. The key signaling mechanisms of cell migration have been identified as the p38 mitogen-activated protein kinase and the p21-activated kinase 1 pathways. ASM cells contain ${\beta}2$-adrenergic receptors and glucocorticoid receptors. They may represent a key target for ${\beta}2$-adrenergic receptor agonist/corticosteroid interactions which have antiproliferative activity against a broad spectrum of mitogens.

• Journal of Chest Surgery
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• 제36권2호
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• pp.86-90
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• 2003

폐 형성에 활성적인 또는 억제적인 기능을 갖고 있다고 알려져 있는 FGF-7 성장인자, BMP수용체 II, 그리고 TGF-$\beta$ 수용체 II 유전자의 비정상 발현이 폐기포 생성에 관여하는지를 각각의 단일성 클론 항체를 사용하여 수술로 절제된 자연기흉 환자의 폐기포 조직들을 면역조직염색 방법으로 염색하여 관찰하였다. 대상 및 방법: 재발성 또는 지속성 기흉으로 흉강경 또는 개흉술로 폐기포 절제술을 실시한 환자들을 대상으로 하였다. 총 31명의 환자로 15세에서 39세까지 연령분포를 보였으며 남자 30명, 여자 1명이었다. 폐기포 절제는 비디오흉강경이나 소절개개흠술을 통하여 폐기포벽에 손상을 가하지 않게 주의하면서 비디오흉강경용 스태플러(Endo GIA stapler)를 이용하여 절제하였으며 가능한 원형을 유지하여 신선한 상태로 포르마린에 고정하여 면역조직화학적 연구를 위한 표본을 만들었다. 폐기포 조직 슬라이드를 단일클론성 항 TGF-$\beta$ 수용체 II, BMP수용체 II 그리고 FGF-7인자 항체를 이용하여 면역조직학적 염색방법으로 관찰하였다. 결과: 전체 환자 31명중 TGF-$\beta$ 수용체 II항체에 양성 반응을 나타낸 환자수는 모두 24명이었다. 이들 중에는 18명이 강한 양성 반응을 보였고, 6명이 약한 양성 반응을 보였다 면역조직화학적 염색 결과를 고배율 현미경으로 살펴보면, TGF-$\beta$ 수용체 II의 염색이 기흉과 정상 폐조직 경계 부위에서 측히 강하게 염색됨이 관찰되었다. 이에 반하여, BMP수용체 II 그리고 FGF-7인자의 항체를 이용한 면역조직학적 염색 결과는 모든 환자의 조직들에서 음성으로 관찰되었다. 결론: 폐 조직이 형성될 때, 억제유전자의 역할을 담당하고 있다고 알려진 TGF-$\beta$ 수용체 II의 발현이 증가되면서 폐기포가 생성될 수 있다는 가능성을 제시하였다. 이번 결론은 면역조직학적 염색 실험 결과만으로 밝혀진 사실임으로 좀 더 체계적인 분자생물학적 인 연구가 요구된다.

• 대한수의학회지
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• 제44권4호
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• pp.497-505
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• 2004

The proliferation of mesangial cells has been associated with the development of diabetic nephropathy. The cell proliferation has been regulated by diverse growth factors. Among them, insulin like growth factors(IGFs) are also involved in the pathogenesis of diabetic nephropathy. However, it is not yet known about the effect of high glucose on IGF-I and IGF-II secretion and the relationship between high glucose-induced secretion of IGFs and PKC or oxidative stress in the mesangial cells. Thus, we examined the mechanisms by which high glucose regulates secretion of IGFs in mesangial cells. High glucose(25 mM) increased IGF-I and IGF-II secretion. High glucose-induced increase of IGF-I and IGF-II secretion were blocked by taurine($2{\times}10^{-3}$ M), N-acetyl cystein(NAC, $10^{-5}M$), or GSH($10^{-5}M$) (antioxidants), suggesting the role of oxidative stress. High glucose-induced secretion of IGF-I and IGF-II were blocked by H-7, staurosporine, and bisindolylmaleimide I(protein kinase C inhibitors). On the other hand, high glucose also increased lipid peroxide (LPO) formation in a dose dependent manner. In addition, high glucoseinduced stimulation of LPO formation was blocked by PKC inhibitors. These results suggest that PKC is responsible for the increase of oxidative stress in the action of high glucose-induced secretion of IGF-I and IGF-II in mesangial cells. In conclusion, high glucose stimulates IGF-I and IGF-II secretion via PKCoxidative stress signal pathways in mesangial cells.

• 대한한방내과학회지
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• 제29권1호
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• pp.42-66
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• 2008

Aconiti Tuber is a traditional medicinal plant generally used in Oriental medicine therapy. In this study, we investigated the biochemical mechanisms of anti-proliferative effects by the methanol extract of Aconiti tuber (MEBJ) in Caki-1 human renal cell carcinoma cells. It was found that MEBJ could inhibit, in a dose-dependent manner, cell growth which was associated with apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase. Apoptosis of Caki-1 cells by MEBJ was associated with an up-regulation of pro-apoptotic Bax expression, and a down-regulation of anti-apoptotic Bcl-2 in a dose-dependent manner; however, the levels of IAP family were not affected. MEBJ treatment also induced the proteolytic activation of caspase-3 and -8, and a inhibition of poly(ADP-ribose) polymerase (PARP) and $PLC{\gamma}1$ protein. Furthermore, MEBJ treatment caused a dose-dependent inhibition of iNOS and cyclooxygenase-2 (Cox-2). Though further studies will be needed to identify the active compounds that confer the anti-cancer activity of MEBJ, the present findings provide important new insights into the possible molecular mechanisms of the apoptotic activity of MEBJ in cancer cells.

• 지질공학
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• 제12권1호
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• pp.95-109
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• 2002

새로이 형성되는 이차광물들이 콘크리트의 조기 성능 저하 (열화)에 미치는 영향은 현재까지 명확히 규명되지 않고 있다. 이들 광물들은 시멘트 페이스트와 골재간의 화학적 반응의 결과로 시멘트 페이스트 내에 형성된다. 조기 성능 저하 현상을 보이는 미국 아이오와주의 콘크리트 포장의 고속도로들로부터 채취된 시료들 내의 골재와 시멘트 페이스트에서의 화학적 광물학적 변화를 규명하기 위하여 암석학적 관찰과 SEM/EDAX 분석을 실시하였다. 이러한 분석에 의거 성능 저하에 연관된 이차광물의 형성과 팽창 메카니즘에 대하여 연구하였다. 브루사이트(Brucite, Mg(OH)2)는 골재의 탈백운석화(dedolomitization) 반응의 결과로 시멘트 페이트스 내에 생성되는 잠재적인 팽창성 광물이다. 시멘트 페이스트의 균열현상은 이들 광물과 공간적인 연관성을 보여주지는 않으나, 대부분이 극 미세입자의 크기로 조기 성능 저하 현상을 나타내는 콘크리트의 시멘트 페이스트 내에 광범위하게 산재되어 나타난다. 무수한 미세공간들에서의 이들 광물 성장에 의한 팽창성 응력은 콘크리트내부의 약한 부분에서 균열로 나타난다. 에트린자이트(3CaO.Al2O3.3CaSO4.32H2O)는 많은 작은 공극들을 완전히 채우고 있으며, 큰 공극들의 가장자리에 테두리와 같은 형태로 나타난다. 미세한 에트린자이트가 많은 콘크리트 시료들의 시멘트 페이스트에 산재해서 나타나기도 한다. 조기 성능 저하의 원인이 되는 시멘트 페이스트의 심한 균열이 에트린자이트와 공간적으로 연관되어 나타나는데, 이러한 사실은 에트린자이트가 콘크리트의 성능 저하에 기여한다는 것을 지시한다. 황철석 (FeS2)이 일반적으로 골재 내에 산재하는데, 이 광물의 산화작용의 산물이 많은 콘크리트 시료들에서 관찰된다. 이런 황철석의 산화작용은 에트린자이트를 형성하기 위한 황산염을 공급하게된다.

• International Journal of Oral Biology
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• 제47권3호
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• pp.41-48
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• 2022

Ulva compressa Linnaeus (UCL) is a green algae seaweed that performs photosynthesis and is used as a food material in some Asian regions including Korea. It is known to be the dominant species in copper ion-contaminated seas, and many studies on copper ion resistant mechanisms have been reported. UCL is known to have an excellent antioxidant effect, but limited information is available regarding its other physiological activities. In this study, we investigated the anticancer activity of 30% prethanol extracts of Ulva compressa Linnaeus (30% PeUCL) and the underlying mechanisms of its activity on human FaDu hypopharyngeal squamous carcinoma cells. The 30% PeUCL extracts suppressed FaDu cell viability without affecting normal cells (L929), as determined by MTT and viability assays. Furthermore, the 30% PeUCL extracts induced apoptosis, as determined by DAPI staining. The 30% PeUCL extracts inhibited colony formation effectively as well as wound-healing of FaDu cells, even at noncytotoxic concentrations. In addition, 30% PeUCL extracts induced apoptosis significantly through proteolytic cleavage of caspase-3, -7, and -9, and poly (ADP-ribose) polymerase, and by downregulation of Bcl-2 and upregulation of Bax in FaDu cells, as determined by Western blot analysis. Collectively, these results suggest that the inhibitory effect of 30% PeUCL extracts on the growth of oral cancer cells, colony formation and wound-healing may be mediated by caspase- and mitochondrial-dependent apoptotic pathways in human FaDu hypopharyngeal squamous carcinoma cells. Therefore, 30% PeUCL extracts can be administered as a natural chemotherapeutic drug for the treatment of human oral cancers.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.103-110
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• 2022

Ultrafine Particle number and size distributions were simultaneously measured at rural area around the power plant in Dangjin, South Korea. New Particle formation and growth events were frequently observed during January, 2021 and classified based on their strength and persistence as well as the variation in geometric mean diameter(GMD) on January 12, 21 and 17. In this study, we investigated mechanisms of new particle growth based on measurements using a high resolution time of flight aerosol mass spectrometer(HR-ToF-AMS) and a scanning mobility particle sizer(SMPS). On Event days(Jan 12 and 21), the total average growth rate was found to be 8.46 nm/h~24.76 nm/hr. These growth rate are comparable to those reported for other urban and rural sites in South Korea using different method. Comparing to the Non-Event day(Jan 17), New Particle Growth mostly occurred when solar radiation is peaked and relative humidity is low in daytime, moreover enhanced under the condition of higher precusors, NO₂ (39.9 vs 6.2ppb), VOCs(129.5 vs 84.6ppb), NH₃(11 vs 4.7ppb). The HR-ToF-AMS PM_1.0 composition shows Organic and Ammoniated nitrate were dominant species effected by emission source in domestic. On the other hand, The Fraction of Ammoniated sulfate was calculated to be approximately 16% and 31% when air quality is inflow from China. Longer term studies are needed to help resolve the relative contributions of each precusor species on new particle growth characteristics.

• 한국컴퓨터정보학회논문지
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• 제28권11호
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• pp.209-226
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• 2023

국경 간 전자상거래는 중국의 대외무역을 안정시키고, 중국 대외무역의 전환과 업그레이드를 추동하며, 글로벌 경제 발전과 안정에 기여하는 결정적인 힘으로 부상했다. 이에 따라 국경 간 전자상거래의 고품질 발전을 추동하는 것은 중국 업계 내에서 공동의 난제로 되었습니다. 그러나 국경 간 전자상거래가 빠르게 성장하면서 품질 혼재, 치열한 경쟁, 가격 경쟁 등 새로운 현상과 도전에 직면해 있다. 브랜드는 주체를 식별하는 구별표지 역할을 하며 브랜드 구축은 국경 간 전자상거래에서 고품질 발전을 이룩하는 신중한 선택이다. 이 글은 정성적 접근법과 정량적 접근법이 결합된 브랜드 이론을 활용하며, 국경 간 전자상거래 기업 운영 내의 주요 요소에 구체적으로 초점을 맞춘다. 중국 국경 간 전자상거래 기업의 내부 운영 내에서 브랜드의 형성과 발전에 영향을 미치는 핵심 요소들에 대한 분석을 통해 그들의 내부 형성 메커니즘을 조사하고 브랜드 형성에 영향을 미치는 이들 중요요소들의 중요성을 평가한다. 연구과정은 해외 소비자의 데이터를 바탕으로 실증분석을 실시하여 궁극적으로 국경 간 전자상거래 기업의 브랜드 개발을 위한 일정한 지침을 제공하고 있다.

• 천문학회보
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• 제39권1호
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• pp.37.1-37.1
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• 2014

There exists strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies; however it is still under debate how such a relation comes about and whether it is relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their host galaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedback may hence be responsible for the eventual quenching of star formation and halting of galaxy growth. A rich multi-wavelength dataset ranging from the X-ray regime (Chandra), to far-IR (Herschel), and radio (WSRT) is available for the North Ecliptic Pole field, most notably surveyed by the AKARI infrared space telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star-formation properties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radio-AGN below redshift z=2 and at a radio 1.4 GHz flux density limit of 0.1 mJy. Using broadband SED modeling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this field, while offering evidence supporting a "maintenance" type of feedback from powerful radio-jets.