다약제내성 발현 암세포에서 99mTc-sestamibi와 99mTc-tetrofosmin 섭취의 비교

유정아,정신영,서명랑,곽동석,안병철,이규보,이재태 대한핵의학회 2003 핵의학 분자영상 Vol.37 No.3

목적 : 다약제내성이 유발된 암세포에서 ^99mTc-sestamibi와 ^99mTc-tetrofosmin의 암세포 내 섭취정도를 비교하고 다약제내성 극복제로 잘 알려진 verapamil 과 cyclosporin A 처리에 의한 두 방사성 의약품의 암세포 내 섭취정도를 비교해 보았다. 재료 및 방법 : Doxorubicin으로 다약제내성이 유발된 HCT15/CL02 대장암 세포와 doxorubicin과 vincristine으로 다약제내성을 유발시킨 K562(Adr)과 K562(Vcr) 백혈병 세포를 사용하였다. 다약제내성의 발현은 RT-PCR로 증명하였으며, vetapamil은 1, 10, 50, 100, 200 ㎛의 농도로, cyclosporin A는 0.1, 1, 10, 50, 100 ㎛의 농도로 각각 사용하였다. MIBI와 tetrofosmin의 암세포내 섭취는 37℃에서 1 × 10_6 cell/㎖ 농도의 단일세포 부유상태에서 1, 15, 30, 45, 60분 간격으로 배양하여 각 시간대별로 상층액과 침전물을 분리하여 각각의 방사능을 감마 계수기로 측정하였다. 결과 : 다약제내성이 발현된 암세포에서는 모세포에 비하여 MIBI와 tetrofosmin의 섭취가 감소되었다. 두 방사성약품의 섭취정도는 HCT15/CL02세포와 K562(Adr)세포에서는 유의한 차이가 없었으나, K562(Vcr)세포에서는 MIBI가 tetrofosmin보다 다소 높았다. Verapamil과 cyclosporin A를 처리하였을 때 MIBI와 tetrofosmin의 섭취율은 기저치보다 모두 증가하였고, verapamil에 의한 MIBI와 tetrofosmin의 섭취율(30분)을 기저치(30분)와 비교해 본 결과 HCT15/CL02세포에서 (100㎛)는 각각 11.9배와 6.8배, K562(Adr)세포에서(50 ㎛)는 각각 14.3배와 8배, K562(Vcr)세포에서(10㎛)는 각각 7배와 5.7배 증가하였다. Cyclosporin A에 의한 MIBI와 tetrofosmin의 섭취율(30분)을 기저치(30분)와 비교해 본 결과 HCT15/CL02세포에서(50 ㎛)는 각각 10배와 2.4배, K562(Adr)세포에서(50 ㎛)는 각각 44배와 13배, K562(Vcr)세포에서(10㎛)는 각각 18.8배와 11.8배 증가하여, MIBI의 섭취율이 tetrofosmin보다 1.2배에서 4배정도 높게 나타났다. 결론 : 이러한 결과로 보아 MIBI와 tetrofosmin은 다약제내성의 발현을 평가할 수 있는 방사성의약품으로 판단되며, 다약제내성 극복제의 효능평가에는 MIBI가 tetrofosmin보다 더 우수할 것으로 사료되나, 세포주에 따른 차이가 있을 수 있으므로 보다 많은 세포주에서의 추가적인 연구가 필요할 것이다. Purpose : Cellular uptakes of ^99mTc-sestamibi(MIBI) and ^99mTc-tetrofosmin into cancer cell lines expressing multidrug resistance(MDR) were investigated and compared. The effects of verapamil and cyclosporin A, well-known multidrug resistant reversing agents, on cellular uptake of both tracers were also compared. Materials and Methods : Doxorubicin-resistant HCT15/CL02 human colorectal cell and doxorubicin-resistant K562(Adr) and vincristine-resistant K562(Vcr) human leukemic cells were studied. RT-PCR analysis was used for the detection of mdr1 mRNA expression. MDR-reversal effects with verapamil and cyclosporine A were evaluated at different drug concentrations after incubation with MIBI and tetrofosmin for 1, 15, 30, 45 and 60 min, using single-cell suspensions at 1×10_6 cell/㎖ incubated at 37℃. Radioactivity in supernatants and pellets were measured with gamma well counter. Results : The cellular uptakes of MIBI and tetrofosmin in K562(Adr) and K562(Vcr) were lower than those of parental J562 cell. In HCT15/CL02 cells and K562(Adr) cells, there were no significant difference in cellular uptakes of both tracers, but cellular uptake of MIBI was higher than that of tefrofosmin in K562(Vcr) cells. Coincubation with verapamil resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Verapamil increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 11.9- and 6.8-fold, by K562(Adr) cell by 14.3- and 8-fold and by K562(Vcr) cell by 7- and 5.7-fold in maximum, respectively. Cyclosporin A increased cellular uptakes of MIVi and tetrofosmin by HCT15/CL02 cell by 11.9- and 6.8-fold, by K562(Adr) cell by 14.3- and 8-fold and by K562(Vcr) cell by 7- and 4.7-fold in maximum, respectively. Cyclosporin A increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 10- and 2.4-fold, by K562(Adr) cell 44- and 13-fold and by K562(Vcr) cell by 18.8- and 11.8-fold in maximum, respectively. Conclusion : Taking together, MIBI and tetrofosmin are considered as suitable radiopharmaceuticals for detecting multidrug resistance. However, MIBI seems to be a better tracer than tetrofosmin for evaluation MDR reversal effect of the modulators. Since cellular uptakes of both tracers might differ in different cell types, further experiments regarding differences in cellular uptakes between cell types should be explored.

THE PROCESS OF THE DEVELOPMENT OF HYPOXIA IN AN ABNORMAL BLOOD FLOW

Kwak, Min-Kyu,Shin, Byeong-Chun,Go, Jae-Gwi The Honam Mathematical Society 2008 호남수학학술지 Vol.30 No.1

Interrupted blood flow diminishes the concentration of oxygen in tissues. Hypoxia first appears in the region distal to the capillaries and grows throughout the entire t issue. However, the time-wise evolution of hypoxic area is diverse when some of capillaries are blocked in a multi-capillary domain with different oxygen squirt. The process of the development of hypoxia through time course is analyzed mathematically in the domain. Each source in steady state is controlled by a time sensitive function to simulate the occlusion.

DOB기반 SEA의 힘 제어

문병윤(Byeong-Yun Mun),박승규(Seung-Kyu Park),곽군평(Gun-Pyeong Kwak) 대한전기학회 2016 대한전기학회 학술대회 논문집 Vol.2016 No.7

The Process of The Development Of Hypoxia In An Abnormal Blood Flow

( Min Kyu Kwak ),( Byeong Chun Shin ),( Jae Gwi Go ) 호남수학회 2008 호남수학학술지 Vol.30 No.1

원발성 간암파열환자에서 그 생존에 영향을 미치는 인자

안병철(Byeong Cheol Ahn),이양일(Yang Il Lee),최성곤(Seng Gon Choi),권중구(Joong Gu Kwen),이창형(Chang Hyung Lee),윤영미(Young Mee Yun),탁원영(Won Young Tak),관규식(Kyu Shik Kwak),최용환(Yong Hwan Choi),정준모(Joon Mo Chung) 대한내과학회 1994 대한내과학회지 Vol.46 No.1

N/A Background: Even though the hepatoma rupture has been known to be one of the fatal complications of hepatoma, the detailed studies on it were few in Korea. Methods: In order to investigate whether the he- patoma rupture can affect the survival of hepatoma patients or not, and also which factors can influence the prognosis of patients with hepatoma rupture, we studied 67 patients with hepatoma rupture and 74 age-matched hepatoma patients without rupture. Results: 1) Incidences of cirrhosis, ascites, hepatic encephalopathy, and unfavorable grade of Child`s classification were more prevalent in rupture group than in control group. Rupture group showed lower mean values of hemoglobin, prothrombin time, total protein and albumin, and higher mean level of GOT than those of control group. 2) But, there was no significant difference in survival time between rupture group and control group. 3) In rupture group, the survival time was more prolonged in patients with more favorable grade of Child`s classification, The survival time tended to be more prolonged in patients treated with TAE method than those managed with conservative treatment, but unfortunately, the results was statistically not significant, 4) In control group, survival time was prolonged in patients with more favorable grade of Child's classification and in those treated with TAE method. Conclusion: Treatment modality and liver status are most significant prognostic factors in hepatoma rupture patients and TAE method should be considered.

Thermodynamic assessment of carbazole-based organic polycyclic compounds for hydrogen storage applications via a computational approach

Shin, Byeong Soo,Yoon, Chang Won,Kwak, Sang Kyu,Kang, Jeong Won Elsevier 2018 International journal of hydrogen energy Vol.43 No.27

<P><B>Abstract</B></P> <P>Liquid organic hydrogen carriers (LOHCs) are promising candidates for storage and transport of renewable energy due to their reversible reaction characteristics. For the proper assessment of candidate molecules, various thermochemical properties are required, and significant experimental efforts are necessary. In this work, we suggest a systematic method for the estimation of thermochemical properties for LOHC candidate molecules combining Density Functional Theory (DFT) calculations, Conductor-like Screening Model (COSMO) and Molecular Dynamics (MD) simulations. We applied the suggested method for the assessment of previously reported LOHC materials. Based on the analysis, new candidates of carbazole-derivative compounds (<I>N</I>-acetylcarbazole, <I>N</I>-phenylcarbazole, <I>N</I>-benzoylcarbazole, and 4-methyl-4H-benzocarbazole) are suggested, and their properties are estimated and reviewed. Calculation results show that these candidates can provide high theoretical hydrogen uptake capacities above 6 wt% and optimal heats of dehydrogenation in the liquid phase. Analysis on the stereoisomerism showed that the structure-selectivity toward less stable stereoisomers of the hydrogen-rich form is preferable for the dehydrogenation process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The existing LOHCs were re-evaluated in terms of thermodynamics. </LI> <LI> A new types of carbazole-derivative compounds are proposed as LOHCs. </LI> <LI> All proposed candidates satisfy the thermodynamic standards. </LI> <LI> Unstable isomers of hydrogen-rich form showed thermal efficient for dehydrogenation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Simultaneous Enhancement of Upconversion and Downshifting Luminescence via Plasmonic Structure

Lee, Kyu-Tae,Park, Jong-Hyun,Kwon, S. Joon,Kwon, Hyun-Keun,Kyhm, Jihoon,Kwak, Kyung-Won,Jang, Ho Seong,Kim, Su Yeon,Han, Joon Soo,Lee, Sung-Hwan,Shin, Dong-Hun,Ko, Hyungduk,Han, Il-Ki,Ju, Byeong-Kwon American Chemical Society 2015 NANO LETTERS Vol.15 No.4

<P>We describe a metal nanodisk–insulator–metal (MIM) structure that enhances lanthanide-based upconversion (UC) and downshifting (DS) simultaneously. The structure was fabricated using a nanotransfer printing method that facilitates large-area applications of nanostructures for optoelectronic devices. The proposed MIM structure is a promising way to harness the entire solar spectrum by converting both ultraviolet and near-infrared to visible light concurrently through resonant-mode excitation. The overall photoluminescence enhancements of the UC and DS were 174- and 29-fold, respectively.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-4/nl5049803/production/images/medium/nl-2014-049803_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl5049803'>ACS Electronic Supporting Info</A></P>

Direct Three-Dimensional Observation of Core/Shell-Structured Quantum Dots with a Composition-Competitive Gradient

Chae, Byeong Gyu,Lee, Jun Ho,Park, Seongyong,Lee, Eunha,Kwak, Chang Min,Jafari, Majid,Jeong, Young Kyu,Park, Chan Gyung,Seol, Jae Bok American Chemical Society 2018 ACS NANO Vol.12 No.12

<P>Synthesizing semiconductor nanoparticles through core/shell structuring is an effective strategy to promote the functional, physical, and kinetic performance of optoelectronic materials. However, elucidating the internal structure and related atomic distribution of core/shell structured quantum dots (QDs) in three dimensions, particularly at heterostructure interfaces, has been an overarching challenge. Herein, by applying complementary analytical techniques of electron microscopy and atom probe tomography, the dimensional, structural, topological, and compositional information on commercially available 11.8 nm-sized CdSSe/ZnS QDs were obtained. Systematic experiments at high resolution reveal the presence of a 1.8 nm-thick Cd<I><SUB><I>x</I></SUB></I>Zn<SUB>1</SUB><I><SUB>-<I>x</I></SUB></I>S inner shell with a composition gradient between the CdSe core and the ZnS outermost shell. More strikingly, the inner shell shows compositional variation because of competitive atomic configuration between Cd and ZnS, but it structurally retains a zinc-blende crystal structure with the core. The inner shell may grow through the decreased reactivity of S with Cd, followed by atomic diffusion-related processes. The composition-competitive gradient inner shell alleviates lattice misfit strain at heterostructure interfaces, thereby enhancing the quantum yield and photostabilty to a greater extent than those of other single-shell structures. Thus, this precise measurement approach could offer a potential pathway to develop a wide variety of three-dimensional core/shell-structured materials.</P> [FIG OMISSION]</BR>

동북아 물류거점화를 위한 항만배후부지 구축전략에 관한 실증연구

윤병구(Byeong-Goo Yoon),곽규석(Kyu-Seok Kwak),안기명(Ki-Myung Ahn),김명재(Myung-Jae Kim) 한국항해항만학회 2005 한국항해항만학회지 Vol.29 No.10

본 논문의 목적은 우리 항만이 동북아 거점항만으로 변신하는데 필요한 항만배후부지전략을 도출하여 거점항만으로의 발전전략의 적합성을 분석하였다. 전략요인으로는 크게 개발정책방향, 개발방법론 및 부지조성전략요인으로 구분하여 분석하였다. 분석결과에 의하면, 부산항이 동북아 물류중심항만이 되기 위해서는 현재 진행 중인 항만배후부지가 실질적인 부가가치를 창출할 수 있도록 개발되는 것이 매우 중요한 것으로 나타나고 있다. The purpose of this research is to verify the strategic fitness and relevance of the distribution park for a hub port in Northeast Asia and to find a method to be a hub-port with a competitive edge. The strategic factor of distribution park development are policy, methodology and promotion method. So these factors are analysed by structural equation model. The essential results of the research show that distribution park should be actually developed to produce value-added and to be port cluster.

연안개발에 따른 냉배수 배출 영향 검토

김병국(Byeong-KuK Kim),김명원(Myeong-Won Kim),곽경일(Gyeong-Il Kwak),김종규(Jong-Kyu Kim) 한국해양환경·에너지학회 2022 한국해양환경·에너지학회 학술대회논문집 Vol.2022 No.6