• BMB Reports
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• v.40 no.4
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• pp.547-553
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• 2007

Many motifs along the 1.2 kb myostatin promoter (MSTNpro) in sheep have been found by the MatInspecter program in our recent study. To further verify the role of the motifs and better understand the transcriptional regulation mechanism of the myostatin gene in sheep, the reporter gene EGFP (enhanced green fluorescent protein) was selected and the wild-type (W) vector MSTNPro$^W$-EGFP or motif-mutational (M) vector MSTNPro$^M$-EGFP were constructed. The transcriptional regulation activities were analyzed by detecting the fluorescence strength of EGFP in C2C12 myoblasts transfected with the vectors. The results showed that E-box (E) 3, E4, E5 and E7, particularly E3, E5 and E7, had important effects on the activity of the 1.2 kb sheep myostatin promoter. In addition, we also detected several other important motifs such as MTBF (muscle-specific Mt binding factor), MEF2 (myocyte enhancer factor 2), GRE (glucocorticoid response elements) and PRE (progesterone response elements) along the sheep myostatin promoter by the mutational analysis.

• Molecules and Cells
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• v.25 no.1
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• pp.131-137
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• 2008

Crk-associated substrate (CAS) is a focal adhesion protein that is involved in integrin signaling and cell migration. CAS deficiency reduces the migration and spreading of cells, both of which are processes mediated by Rac activation. We examined the functions of v-Crk, the oncogene product of the CT10 virus p47gag-crk, which affects cell migration and spreading, membrane ruffling, and Rac activation in CAS-deficient mouse embryonic fibroblasts (CAS-/- MEFs). CAS-/- MEFs showed less spreading than did CAS+/+ MEFs, but spreading was recovered in mutant cells that expressed v-Crk (CAS-/-v-Crk MEF). We observed that the reduction in spreading was linked to the formation of membrane ruffles, which were accompanied by Rac activation. In CAS-/- MEFs, Rac activity was significantly reduced, and Rac was not localized to the membrane. In contrast, Rac was active and localized to the membrane in CAS-/-v-Crk MEFs. Lamellipodia protrusion and ruffle retraction velocities were both reduced in CAS-/- MEFs, but not in CAS-/-v-Crk MEFs. We also found that microinjection of anti-gag antibodies inhibited the migration of CAS-/-v-Crk MEFs. These findings indicate that v-Crk controls cell migration and membrane dynamics by activating Rac in CAS-deficient MEFs.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.517-528
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• 1985

Pulmonary function studies today are generally accepted as an integral part of the evaluation of poor-risk patients who are to have pulmonary surgery. The effect of various pulmonary surgery on lung function was investigated in 54 patients in whom comprehensive lung function test were performed before and between 2 months and 14 months after operation at the Department of Thoracic Surgery, Seoul National University Hospital. According to the result of analysis, the effect of pulmonary resection on forced flow rate was keeping with the change of lung volume, and the preoperative level of ventilatory function plays a major role in determining postoperative loss of functioning lung. Although all measures of expiratory flow [FVC, FEV1, FEFO.2-1.2, MEF50, FEF25-75] have the same percentage of reproducibility, but FEV1 shows most sensitive, reliable linear correlation with the functioning pulmonary tissue loss than other parameters. The linear regression lines derived from the correlation between preoperative [X] and postoperative [Y] FEV1 on various surgical procedures were as follows: 1. Y = 0.57X 0.03. in pneumonectomy group of lung cancer[r=0.84]. 2. Y = 0.56X + 0.33. in lobectomy group of lung cancer[r=0.79]. 3. Y = 0.69X + 0.25. in lobectomy group of pulmonary infection[r=0.91].

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1031-1037
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• 2008

Macrolide antimicrobial agents including erythromycin, roxithromycin, clarithromycin, and azithromycin are commonly used in the treatment of respiratory tract infections in children. Newer macrolides that have structural modifications of older drug erythromycin show improved change in the spectrum of activity, dosing, and administration. However, recent studies reported that increasing use of macrolide antibiotics is the main force driving the development of macrolide resistance in streptococci. In particular, azithromycin use is more likely to select for macrolide resistance with Streptococcus pneumoniae than is clarithromycin use, a possible reflection of its much longer half life. Recently, erythromycin resistance rates of S. pneumoniae and Streptococcus pyogenes are rapidly increasing in Korea. Two main mechanisms of acquired macrolide resistance have been described, altered binding site on the bacterial ribosome encoded by the ermB gene and active macrolide efflux pump encoded by the mef gene. Relationship between the susceptibility of S. pneumoniae and the response to macrolides has been shown in studies of acute otitis media, but less clear in cases of pneumonia. This article reviews the spectrum of activity, pharmacokinetic properties, mechanisms of action and resistance, and clinical implication of resistance on the treatment of respiratory tract infections in children.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.1
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• pp.35-43
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• 2016

PURPOSE: The purpose of this study was to investigate the effects of passive stretching exercises of the scalene muscles known as respiratory accessory muscles, on forced vital capacity. METHODS: Ten of the participants were randomly selected as an experiment group to perform passive stretching exercises on the scalene muscles. Ten additional students were selected randomly as a control group. The forced vital capacity was assessed by using a digital spirometer (Pony FX, COSMED Inc, Italy) both before and after the passive stretching exercises were performed. Subsequently, passive stretching exercises of the scalene muscles were performed in the experimental group. There were no interventions to the control group. RESULTS: As for the forced vital capacity (FVC), the experiment group showed significant increase in items of forced vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$), peak expiratory flow (PEF), forced expiratory volume in 1 second/vital capacity ($FEV_1/VC$), and maximal expiratory flow 75%(MEF 75%) after the scalenemuscles passive stretching exercises were performed. The control group, however, showed no change. CONCLUSION: This study demonstrated that passive stretching exercises of the scalene muscles could be helpful for forced vital capacity improvement.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.67-72
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• 2008

The use of doxorubicin, which is one of the most effective anticancer agents, is often limited by occurrence of acquired resistance in tumor cells. GSH has been shown to be involved in the development of this drug resistance. Transcription factor Nrf2 governs the expression of GSH synthesizing glutamylcysteine ligase (GCL), as well as multiple phase 2 detoxifying enzymes. Here we show that Nrf2 is one of factors determining doxorubicin sensitivity. Nrf2-deficient fibroblasts (murine embryonic fibroblasts, MEF) were more susceptible to doxorubicin mediated cell death than wild-type cells. Doxorubicin treatment elevated levels of Nrf2-regulated genes including NAD(P)H: quinone oxidoreductase (Nqo1) and GCL in wild-type fibroblasts, while no induction was observed in Nrf2-deficient cells. Doxorubicin resistance in human ovarian SK-OV cells was reversed by treatment with L-buthionine-sulfoxamine (BSO), which is depleting intracellular GSH. Finally, transfection of SK-OV cells with Nrf2 siRNA resulted in exacerbated cytotoxicity following doxorubicin treatment compared to scrambled RNA control. These results indicate that the Nrf2 pathway, which plays a protective role in normal cells, can be a potential target to control cancer cell resistance to anticancer agents.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.40.2-40.2
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• 2018

외계행성 탐색시스템으로 관측한 영상은 한국천문연구원 본원에 있는 자료처리 시스템으로 실시간 전송된다. 이를 위해 한국과학기술정보연구원이 운영 중인 첨단망과 UDP 전송 프로그램을 활용하고 있으며 연간 약 140TB의 관측 영상을 칠레 55Mbps, 남아공 39Mbps, 호주 410Mbps의 속도로 전송하고 있다. 관측 영상이 전송되면 MEF 포맷으로 구조화 하고 bias, flat, crosstalk 보정과 bad pixel masking 등의 전처리 과정을 거쳐 각 연구과제별로 실시간 배포하고 있다. 중력렌즈 연구를 위한 우리 은하 중심부 관측영상은 차감영상 기법을 사용하여 약 3억 개의 별에 대해 측광하고 있으며, $18K{\times}18K$ 크기의 대용량 관측 영상을 빠르고 효율적으로 처리하기 위해 256개로 분할하여 분산처리하고 있다. 2014년부터 자료처리를 위한 시스템을 구축하고 증설하였으며 현재 11대의 서버(212Core)와 2.7PB의 NAS 스토리지를 운영하며 연간 700TB이상의 자료를 처리하고 있다. 우리은하 중심부 측광자료에서 검출된 변광 현상을 정리하여 측광데이터베이스를 구축하였다. 본 발표에서는 KMTNet 실시간 자료처리 과정에 대한 상세한 내용과 향후 자료처리 시스템 개선방향에 대해 소개한다.

• Journal of Korean Physical Therapy Science
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• v.19 no.1
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• pp.63-69
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• 2012

Background : The purpose of this study was to investigate the frequency domain characteristics of ground reaction forces during quiet standing on inclined surfaces twenty healthy individuals(10 elderly women $68.78{\pm}3.29$ years and 10 young women $20.90{\pm}0.74$ years) participated. Methods : Subjects stood in quiet stance over a force platform positioned in one of three different fixed positions: flat, down and up. Healthy participants completed with eyes open for 120 s trials. Evaluation of postural control were generally based on the interpretation of center of pressure(COP) time series. The COP have been determined using an experimental setup with 3D kinematic and the ground reaction force system. All the data were expressed means and standard deviation by using SAS package program. Results : SEF 50% were not significant in AP and ML direction according to surface slope of both groups. SEF 95% were showed highest frequency in AP direction on down slope of both groups. MEF were not significant all direction according to surface slopes of elderly women. There was no difference between young and elderly women. Conclusion : Elderly women used to ankle strategy during a quiet stance according to COP perturbation of AP direction showed more expanded than ML direction. SEF 95% were showed highest frequency on down slope in elderly women who showed more used ankle strategy for postural control on down slope.

• The Korean Journal of Zoology
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• v.30 no.3
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• pp.311-323
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• 1987

생쥐의 섬 유아세포(MEP)와 종양세포(SCK)를 이용하여 정상세포와 종양세포 사이에 열 감수성의 차이가 있는지의 여부 및 환경의 pH가 이 세포들의 열감수성과 heat shock protein(HSP) 합성에 미치는 영향을 생존곡선과 HSP합성 kinetics등을 써서 검토하였다. MEF와 SCK 세포를 정상 pH(7.4) 또는 산성 pH(6.7)에서 42"C에서 2시간 온열처리 후 3일간에 걸쳐 생존을을 비교해 븐 결과, ME선와 SCK세포 사이에 생득적 열강수성의 차이는 없었고 산성 P광에서는 세포의 종류에 관계없이 열감수성 이 증감되었다. 온열처리의 결과 유도되는 내일성이 conditioning Leat의 크기와 어떤 관계가 있는지를 보기 위해서 45"C에서 5분 또는 20분을 주어본 결과 체은 conditioning heat를 주었을 때 내일성이 신속히 그리고 높은 수준으로 발생하였고, 이러한 열 감수성의 kinetics는 HSP의 합성 kinetics와 잘 일치하였다. 단백질, 특히 HSP 합성에 미치는 PH의 영 향을 알아보기 위해서 46"C에서 6분간의 heat shock를 주어 본 바 전반적인 단백질 및 major HSP의 합성양상에는 별로 차이를 보이지 않았다. 그러나 SCK 세포에 43"C에서 30분의 온열처리를 주고 새로 합성되는 HSPSP의 kinetics를 검토해 본 결과 정상 P반에서는 0-5시간에 합성이 일어나나 산성 PH에서는 3-9시간에 합성이 일어나서 몇시간의 합성지연이 관찰되었다. 아울러 HSP68, HSPTC, HSP87을 Peptidemapping하여 본 결과 HSP68과 HSP70 은 유사한 peptide fragment pattern을 보여 amino acid sequence는 유사하고 기능도 같을 것으로 추론되었으나 HSP87은 전혀 다른 pattern을 보였다. 전혀 다른 pattern을 보였다.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.1
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• pp.33-41
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• 2004

We developed a cardiac cell model to explain the phenomenon of mechano-electric feedback (MEF), based on the experimental data with rat atrial myocytes. It incorporated the activity of ion channels, pumps, exchangers, and changes of intracellular ion concentration. Changes in membrane excitability and $Ca^{2+}$ transients could then be calculated. In the model, the major ion channels responsible for the stretch-induced changes in electrical activity were the stretch-activated channels (SACs). The relationship between the extent of stretch and activation of SACs was formulated based on the experimental findings. Then, the effects of mechanical stretch on the electrical activity were reproduced. The shape of the action potential (AP) was significantly changed by stretch in the model simulation. The duration was decreased at initial fast phase of repolarization (AP duration at 20% repolarization level from 3.7 to 2.5 ms) and increased at late slow phase of repolarization (AP duration at 90% repolarization level from 62 to 178 ms). The resting potential was depolarized from -75 to -61 mV. This mathematical model of SACs may quantitatively predict changes in cardiomyocytes by mechanical stretch.