• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3219-3226
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• 2014

Chemotherapy continues to be a mainstay of cancer treatment, although drug resistance is a major obstacle. Lipid metabolism plays a critical role in cancer pathology, with elevated ether lipid levels. Recently, alkylglyceronephosphate synthase (AGPS), an enzyme that catalyzes the critical step in ether lipid synthesis, was shown to be up-regulated in multiple types of cancer cells and primary tumors. Here, we demonstrated that silencing of AGPS in chemotherapy resistance glioma U87MG/DDP and hepatic carcinoma HepG2/ADM cell lines resulted in reduced cell proliferation, increased drug sensitivity, cell cycle arrest and cell apoptosis through reducing the intracellular concentration of lysophosphatidic acid (LPA), lysophosphatidic acid-ether (LPAe) and prostaglandin E2 (PGE2), resulting in reduction of LPA receptor and EP receptors mediated PI3K/AKT signaling pathways and the expression of several multi-drug resistance genes, like MDR1, MRP1 and ABCG2. ${\beta}$-catenin, caspase-3/8, Bcl-2 and survivin were also found to be involved. In summary, our studies indicate that AGPS plays a role in cancer chemotherapy resistance by mediating signaling lipid metabolism in cancer cells.

• Journal of Chest Surgery
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• 제22권2호
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• pp.256-264
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• 1989

Modified Blalock-Taussig operation remains the standard technique of systemic-to-pulmonary artery shunt in patients of congenital heart disease with decreased pulmonary blood flow. We reviewed the 41 patients who had been performed modified Blalock-Taussig operation from March 1985 to Feb. 1988, and angiographically measured pulmonary artery size before and after shunt, and calculated pulmonary artery index [PAI] and ratio of left and right pulmonary artery to descending aorta[[LPA+RPA]/dAo]. The mean duration of palliation after shunt operation was 624 days and mean age of the patient at shunt operation was 3.59 years. Mean PAI increased significantly from 131.15*67.11 mm2/M2 preoperatively to 232.70*84.46 mm2/M2 postoperatively. Mean ratio of right and left pulmonary artery to descending aorta also increased significantly from 1.48*0.40 preoperatively to 1.92*0.50 postoperatively. All patients manifested clinical improvement; there was mean decrease in hematocrit of 8.95%, mean increase in arterial oxygen saturation of 11.08%. Pulmonary arterial growth was not influenced by age at operation, initial pulmonary artery size, or graft size, but significantly influenced by antegrade flow. The patients who have some antegrade flow were in more increase of PAI. There were no linear correlation between change of PAI, change of [[LPA+RPA]/dAo], SaO2, and duration. But, according to Scatterplot between change of PAI and duration, some complex correlation was suggested and mean PAI was decreased after 2-year palliation. We concluded that modified Blalock-Taussig operation is excellent palliative surgery for pulmonary artery growth especially on the patient who have some antegrade flow, and the proper duration of palliation was about 2 years.

• 대한수의학회지
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• 제41권2호
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• pp.233-241
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• 2001

Dirofilaria immitis, the causative agent of canine heartworm disease, inhabits mainly in the pulmonary arteries and the heart of dogs and cats, causing circulatory and respiratory disorders. Although diagnosis of the disease is based on the presence of microfilaria in the peripheral blood or of specific antigens released from the adult worms into the peripheral blood, the severity of the infection and the assessment of disease progression are based on the clinical signs and radiographic image analysis. We analysed 12 mixed-bred Jindo dogs naturally infected with Dirofilaria immitis without any clinical signs and compared the radiographic images of the heart and the lung with the number of adult worms at necropsy. The dorsoventral radiographs of 12 infected dogs revealed that the right caudal lobar pulmonary arteries (RCaLPA) were dialated in 66.7% of dogs, whereas the main pulmonary artery segment was enlarged in 50.3% of dogs. The cranial lobar pulmonary arteries (RCrLPA) were dilated or pruned in 33.3% of dogs. All dogs displayed the interstitial lung pattern, while the vertebral heart size (VHS) was of normal range. Although a range of 9 to 166 adult worms (av. 45.6) was found in the pulmonary arteries, in the heart or in the vena cava, no correlation with the radiographic findings and/or with the clinical signs was observed.

• Journal of Ginseng Research
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• 제44권1호
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• pp.67-78
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• 2020

Background: Gintonin (GT), a novel ginseng-derived exogenous ligand of lysophosphatidic acid (LPA) receptors, has been shown to induce cell proliferation and migration in the hippocampus, regulate calcium-dependent ion channels in the astrocytes, and reduce β-amyloid plaque in the brain. However, whether GT influences autophagy in cortical astrocytes is not yet investigated. Methods: We examined the effect of GT on autophagy in primary cortical astrocytes using immunoblot and immunocytochemistry assays. Suppression of specific proteins was performed via siRNA. LC3 puncta was determined using confocal microscopy. Results: GT strongly upregulated autophagy marker LC3 by a concentration- as well as time-dependent manner via G protein-coupled LPA receptors. GT-induced autophagy was further confirmed by the formation of LC3 puncta. Interestingly, on pretreatment with an mammalian target of rapamycin (mTOR) inhibitor, rapamycin, GT further enhanced LC3-II and LC3 puncta expression. However, GT-induced autophagy was significantly attenuated by inhibition of autophagy by 3-methyladenine and knockdown Beclin-1, Atg5, and Atg7 gene expression. Importantly, when pretreated with a lysosomotropic agent, E-64d/peps A or bafilomycin A1, GT significantly increased the levels of LC3-II along with the formation of LC3 puncta. In addition, GT treatment enhanced autophagic flux, which led to an increase in lysosome-associated membrane protein 1 and degradation of ubiquitinated p62/SQSTM1. Conclusion: GT induces autophagy via mTOR-mediated pathway and elevates autophagic flux. This study demonstrates that GT can be used as an autophagy-inducing agent in cortical astrocytes.

• 한국정보통신학회논문지
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• 제11권7호
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• pp.1289-1295
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• 2007

본 논문에서는 유 무선 네트워 킹을 지원하는 TRS 중계기의 전체적인 RF 시스템들을 디지털 방식으로 제어 할 수 있는 고성능 병렬 제어 시스템을 구현하였다. 구현된 시스템은 순 역방향 LPA(Linear Power Amplifier), 순 역방향 LNA(Low Noise Amplifier), 채널카드, 직렬통신(RS-232), 유 무선 TCP/IP 통신의 제어를 담당하는 FPGA(Field Programmable Gate Array) 칩과 전체 시스템의 제어를 관장하는 마스터(Master) 마이크로프로세서, 순 역방향 스펙트럼 분석기(Spectrum Analyzer, SA)를 내장하여 현재 통신되고 있는 채널의 주파수 스펙트럼을 5KHz 단위의 해상도로 관찰할 수 있도록 하는 슬레이브 마이크로프로세서, 각각의 채널카드들을 개별적으로 감시하고 채널카드내의 주파수 합성기(Frequency Synthesizer)를 프로그래밍하기 위한 10개의 채널카드용 마이크로프로세서, 그리고 그 밖의 몇 가지 주변기기들과 회로들로 구성된다. 전체 시스템은 동작의 효율성과 병렬성을 비롯하여 구현의 적합성과 비용을 고려하여 H/W(Hardware) 및 S/W(Software) 부분으로 나누었고, H/W도 FPGA과 마이크로프로세서로 나누어서 최적화를 이루고자 노력하였다.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.3049-3067
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• 2018

최근 조직몰입(organizational commitment) 3요인(정서적 몰입, 규범적 몰입, 지속적 몰입) 모델(Allen, Meyer, 1990, 1991) 관련 연구에서 사람중심 접근법(person-centered approach)이 많은 관심을 받고 있지만 아직 국내 연구자들에게는 크게 확산되지 못하고 있다. 이에 본 논문은 사람중심 접근법의 개념과 관련 자료분석 방법을 군집분석(cluster analysis)과 잠재프로파일분석(latent profile analysis)을 중심으로 소개하고자 한다. 또한 이러한 방법들의 실제 적용 사례를 제시하기 위해 국내 직장인들 349명으로부터 수집한 자료를 바탕으로 군집분석과 잠재프로파일분석을 각각 실행하여 각 분석으로부터 6개의 조직몰입 프로파일 유형들을 도출하였으며 그 결과를 비교하였다. 뿐만 아니라, 조직몰입 프로파일 유형 간 이직의도(turnover intention)의 차이를 살펴봄으로써 도출된 프로파일의 타당성을 확인하였다. 본 논문은 조직몰입에 대한 기존의 변수중심 접근법(variable-centered approach)에 대한 보완적 방법으로 사람중심 접근법이 갖는 의미를 이해하고, 나아가 국내 직장인들의 조직몰입 프로파일 유형을 살펴볼 수 있다는 점에서 국내 연구자들 뿐만 아니라 실무담당자들에게 시사하는 바가 크다고 할 수 있다.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.73-86
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• 2003

Endothelins secreted from keratinocytes are intrinsic madiators for human melanocytes in UVB-induced pigmentation. Antimelanogenic ingredient, 1,2-Ο-diferulylglycerol(SM709) isolated from bamboo extract inhibited the melanin synthesis of Bl6F10 melanoma cells by 62%. To understand the cellular mechanism of antimelanogenic activity of SM709 in human melanocytes, the effects of SM709 on the ET-l-induced $Ca^{2+}$ mobilization were investigated. ET-l receptors in human melanocytes were characterized by using specific antagonist and found that ET-l increased intracellular $Ca^{2+}$ by activating ET-B receptor. SM709 completely blocked the ET-l-induced intracellular $Ca^{2+}$ increase and its inhibitory effect showed dose- and time- dependent manners. To investigate the role of SM709 on intracellular $Ca^{2+}$ store, when the $Ca^{2+}$ store was partially depleted by thapsigargin; a specific inhibitor of ER-type $Ca^{2+}$-ATPase, caffeine-induced $Ca^{2+}$ mobilization did not changed in the presence or absence of SM709, suggesting that SM709 has no effect on the $Ca^{2+}$ store. It is known that LPA receptor and P$_2$ receptor are linked to InsP$_3$ second messenger system. When these receptors in melanocytes were activated by LPA and ATP, the intracellular $Ca^{2+}$ signaling was observed even in the presence of SM709. From the above results, it can be suggested that SM709 has an antimelanogenic activity by antagonizing the ET-B receptor, resulting in subsequent intracellular $Ca^{2+}$ signaling, in UV induced pigmentation.nduced pigmentation.

• Journal of Yeungnam Medical Science
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• 제41권2호
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• pp.113-119
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• 2024

Background: Missing isoniazid (INH) resistance during tuberculosis (TB) diagnosis can worsen the outcomes of INH-resistant TB. The BD MAX MDR-TB assay (BD MAX) facilitates the rapid detection of TB and INH and rifampin (RIF) resistance; however, data related to its performance in clinical setting remain limited. Moreover, its effect on treatment outcomes has not yet been studied. Methods: We compared the performance of BD MAX for the detection of INH/RIF resistances to that of the line probe assay (LPA) in patients with pulmonary TB (PTB), using the results of a phenotypic drug sensitivity test as a reference standard. The treatment outcomes of patients who used BD MAX were compared with those of patients who did not. Results: Of the 83 patients included in the study, the BD MAX was used for an initial PTB diagnosis in 39 patients. The sensitivity of BD MAX for detecting PTB was 79.5%. The sensitivity and specificity of BD MAX for INH resistance were both 100%, whereas these were 50.0% and 95.8%, respectively, for RIF resistance. The sensitivity and specificity of BD MAX were comparable to those of LPA. The BD MAX group had a shorter time interval from specimen request to the initiation of anti-TB drugs (2.0 days vs. 5.5 days, p=0.001). Conclusion: BD MAX showed comparable performance to conventional tests for detecting PTB and INH/RIF resistances. The implementation of BD MAX as a diagnostic tool for PTB resulted in a shorter turnaround time for the initiation of PTB treatment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.118-123
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• 2001

For multi-carrier communication system, power amplifier generate intermodulation products caused by their nonlinear characteristics. Intermodulation products arised around the carrier frequency cannot be filtered out, operate as noise source for tile adjacent channel and thus degrades the quality of communication. In this paper, the 1850MHz-band RF linear power amplifier has been designed and fabricated with feedforward loop. The error signal loop consists of several key components such as phase shifter and attenuator, subtracter. The proposed Linearizer was tested with two-tone signals separated 10MHz apart at the center frequency of 1850MHz. The experimental results show C/I improvement by 14.5${\~}$20dB over 15dB dynamic range(33${\~}$47.8dBm) which gave IMD of 53.25${\~}$59dBc for the designed LPA.

• 대한임상검사과학회지
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• 제47권4호
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• pp.175-181
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• 2015

알러지성 접촉피부염 유발제인 수은의 독성에 대한 청미래덩굴(Smilax china L.) 추출물의 영향을 조사하기 위하여 배양 NIH3T3 섬유모세포에 여러 농도의 메틸수은(methylmercuric chloride, MMC)을 72시간 동안 처리한 후 이들의 세포독성을 조사하였다. 또한, MMC의 독성에 대한 청미래덩굴 추출물의 보호효과를 항산화 측면에서 조사하여 다음과 같은 결론을 얻었다. MMC는 농도 의존적으로 배양 NIH3T3 섬유모세포의 세포생존율을 유의하게 감소하였으며 $XTT_{50}$값이 100 uM 이하로서 고독성(highly-toxic)인 것으로 나타났다. 또한, MMC의 독성이 항산화제인 vit. E에 의하여 방어됨으로서 MMC의 독성에 산화적 손상이 관여하고 있는 것으로 나타났다. 한편, MMC의 세포독성에 대한 청미래덩굴 추출물의 방어효과에 있어서 청미래덩굴 추출물은 MMC에 의하여 감소된 세포생존율을 유의하게 증가시킴으로서 MMC의 독성을 방어하였다. 또한, 청미래덩굴 추출물은 전자공여능(EDA)을 비롯한 SOD-유사 활성(SLA) 및 지질과산화능(LPA)와 같은 항산화 효과를 나타냈다. 이상의 결과로부터 청미래덩굴과 같은 천연 성분은 산화적 손상과 관련된 염증성 피부질환의 치료를 위한 항산화제로서의 미래 가능한 천연소재라고 생각된다.