• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.199-199
• /
• 2013

The distinctive cellular and mitochondrial dysfunctions of a human epithelial lung cancer cell line (H460) from a human lung fibroblastic normal cell line (MRC5) have been studied by dielectric barrier discharge (DBD) plasma treatment. The DBD plasma device have generated large amount of H2O2 and NOx in culture media which is dependent on plasma exposure time. It is found that the cell number of lung cancer cell H460 has been reduced more than the lung normal cell MRC5 as being increased exposure and incubation time. Also these both cell lines have showed mitochondria fragmentation under 5 minutes' plasma exposure, which is a clue of apoptosis. It is noted in this study that AnnexinV staining has showed not only early apoptosis, but also late apoptosis in lung cancer cell H460. Mitochondria enzyme activity and ATP generation have been also much reduced in lung cancer cell H460. Their mitochondrial membrane potential (${\Delta}{\psi}m$) has been found to be reduced in magnitude and shifted to the induced-potential level of cccp, while MRC5 mitochondrial membrane potential has been shifted slightly to that. These distinctively selective responses of lung cancer cell H460 from lung normal cell MRC5 gives us possibility of applying plasma to cancer therapy.

• Toxicological Research
• /
• 제32권3호
• /
• pp.251-258
• /
• 2016

Mesenchymal stem cells (MSCs) have been identified in multiple types of tissue and exhibit characteristic self-renewal and multi-lineage differentiation abilities. However, the possibility of oncogenic transformation after transplantation is concerning. In this study, we investigated the tumorigenic potential of umbilical cord blood-derived MSCs (hUCB-MSCs) relative to MRC-5 and HeLa cells (negative and positive controls, respectively) both in vitro and in vivo. To evaluate tumorigenicity in vitro, anchorage-independent growth was assessed using the soft agar colony formation assay. hUCB-MSCs and MRC-5 cells formed few colonies, while HeLa cells formed a greater number of larger colonies, indicating that hUCB-MSCs and MRC-5 cells do not have anchorage-independent proliferation potential. To detect tumorigenicity in vivo, hUCB-MSCs were implanted as a single subcutaneous injection into BALB/c-nu mice. No tumor formation was observed in mice transplanted with hUCB-MSCs or MRC-5 cells based on macro- and microscopic examinations; however, all mice transplanted with HeLa cells developed tumors that stained positive for a human gene according to immunohistochemical analysis. In conclusion, hUCB-MSCs do not exhibit tumorigenic potential based on in vitro and in vivo assays under our experimental conditions, providing further evidence of their safety for clinical applications.

• Journal of Information Processing Systems
• /
• 제13권5호
• /
• pp.1071-1088
• /
• 2017

For dual-hop multiple-input multiple-output (MIMO) decode-and-forward relaying systems, we propose a selective relaying scheme that uses orthogonal space-time block code (OSTBC) and transmit antenna selection with maximal-ratio combining (TAS/MRC) or vice versa at the first and second hops, respectively. The aim is to achieve an asymptotically identical performance to the dual-hop relaying system with only TAS/MRC, while requiring lower feedback overhead. In particular, we give the selection criteria based on the antenna configurations and the average channel powers for the first and second hops, assuming Rayleigh fading channels. Also, the numerical results are shown for the outage performance comparison between the dual-hop DF relaying systems with the proposed scheme, only TAS/MRC, and only OSTBC.

• Journal of Preventive Medicine and Public Health
• /
• 제15권1호
• /
• pp.47-56
• /
• 1982

Korean versions of British Medical Research Council (MRC), Cornell Medical Index(CMI), and American Thoracic Society 78 (ATS-DLD-78) respiratory questionaires were compared with each other, and were tested the stability, in terms of test-retest reliability, of each questions by self-administration of those to 156 medical students. The results obtained and conclusions drawn are as follow: 1. The degree of agreements between responses to the comparable questions of CMI vs MRC, and of CMI vs ATS-DLD-78 were not satisfactory. There were, however, $71{\sim}100$ per cent of agreement between responses to the questions on Cough, Wheezing, Phlegm, Breathlessness, and Chest illness of ATS-DLD-78 vs MRC questionaire. And the ATS-DLD-78 tended to yield greater number of positive responses than MRC (See Table 4). 2. All of the coefficient of stability of each questions in 3 questionaires were statistically significant, ranged $77{\sim}100$ per cent, except that of the question on episode of cough and phlegm in ATS-DLD-78 questionaire (See Table 5-1). The question is composed of two collateral conditions, 'lasting for 3 weeks or more' and 'each year'. 3. It can be insisted that the Section-B questions of CMI is not proper for use in epidemiologic survey on respiratory illness. And rather than MRC, the ATS-DLD-78 questionaire deserves to prefer to be used in epidemiologic studies on respiratory illness. 4. In question-wording, especially, of inquiring past experience, it is possible to lessen the reliability of the question that including collateral conditions such as 'the duration lasted of symptoms', and moreover, of which words are not common usage. For example, for Korean '10days' or 'half a month' is more familiar time unit rather than 'week'.

• The Korean Journal of Physiology and Pharmacology
• /
• 제9권5호
• /
• pp.263-268
• /
• 2005

Striatum has important roles in motor control, habitual learning and memory. It receives glutamatergic inputs from neocortex and thalamus, and dopaminergic inputs from substantia nigra. We examined effects of dopamine (DA) on the corticostriatal synaptic transmission using in vitro extracellular recording technique in rat brain corticostriatal slices. Synaptic responses were elicited by stimulation of cortical glutamatergic inputs on the corpus callosum and recorded in the dorsal striatum. Corticostriatal population spike (PS) amplitudes were decreased ($39.4{\pm}7.9$%) by the application of $100{\mu}M$ DA. We applied receptor subtype specific agonists and antagonists and characterized the modulation of corticostriatal synaptic transmission by different DA receptor subtypes. $D_2$ receptor agonist (quinpirole), antagonist (sulpiride), and $D_1$ receptor antagonist (SKF 83566), but not $D_1$ receptor agonist (SKF 38393), induced significantly the reduction of striatal PS. Pretreatment neither with SKF 83566 nor sulpiride significantly affected corticostriatal synaptic inhibition by DA. However, the inhibition of DA was completely blocked by pretreatment with mixed solution of both SKF 83566 and sulpiride. These results suggest that DA inhibits corticostriatal synaptic transmission through both $D_1$ and $D_2$ receptors in concert with each other.

• Molecular & Cellular Toxicology
• /
• 제5권3호
• /
• pp.230-236
• /
• 2009

Acrolein, a known toxin in cigarette smoke, is the most abundant electrophilic $\alpha$, $\beta$-unsaturated aldehyde to which humans are exposed in a variety of environmental pollutants, and is also product of lipid peroxidation. Increased unsaturated aldehyde levels and reduced antioxidant status plays a major role in the pathogenesis of various diseases such as diabetes, Alzheimer's and atherosclerosis. The findings reported here show that low concentrations of acrolein induce heme oxygenase-1 (HO-1) expression in RAW 264.7 macrophages. HO-1 induction by acrolein and signal pathways was measured using reverse transcription-polymerase chain reaction, Western blot and immunofluorescence staining analyses. Inhibition of extracellular signal-regulated kinase activity significantly attenuated the induction of HO-1 protein by acrolein, while suppression of Jun N-terminal kinase and p38 activity did not affect induction of HO-1 expression. Moreover, rottlerin, an inhibitor of protein kinase $\delta$, suppressed the upregulation of HO-1 protein production, possibly involving the interaction of NF-E2-related factor 2 (Nrf2), which has a key role as a HO-1 transcription factor. Acrolein elevated the nuclear translocation of Nrf2 in nuclear extraction. The results suggest that RAW 264.7 may protect against acrolein-mediated cellular damage via the upregulation of HO-1, which is an adaptive response to oxidative stress.

• Journal of Ginseng Research
• /
• 제41권3호
• /
• pp.392-402
• /
• 2017

Background: Previously, we reported that Korean Red Ginseng inhibited liver fibrosis in mice and reduced the expressions of fibrogenic genes in hepatic stellate cells (HSCs). The present study was undertaken to identify the major ginsenoside responsible for reducing the numbers of HSCs and the underlying mechanism involved. Methods: Using LX-2 cells (a human immortalized HSC line) and primary activated HSCs, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assays were conducted to examine the cytotoxic effects of ginsenosides. $H_2O_2$ productions, glutathione contents, lactate dehydrogenase activities, mitochondrial membrane permeabilities, apoptotic cell subpopulations, caspase-3/-7 activities, transferase dUTP nick end labeling (TUNEL) staining, and immunoblot analysis were performed to elucidate the molecular mechanism responsible for ginsenoside-mediated cytotoxicity. Involvement of the AMP-activated protein kinase (AMPK)-related signaling pathway was examined using a chemical inhibitor and small interfering RNA (siRNA) transfection. Results and conclusion: Of the 11 ginsenosides tested, 20S-protopanaxadiol (PPD) showed the most potent cytotoxic activity in both LX-2 cells and primary activated HSCs. Oxidative stress-mediated apoptosis induced by 20S-PPD was blocked by N-acetyl-$\text\tiny L$-cysteine pretreatment. In addition, 20S-PPD concentration-dependently increased the phosphorylation of AMPK, and compound C prevented 20S-PPD-induced cytotoxicity and mitochondrial dysfunction. Moreover, 20S-PPD increased the phosphorylation of liver kinase B1 (LKB1), an upstream kinase of AMPK. Likewise, transfection of LX-2 cells with LKB1 siRNA reduced the cytotoxic effect of 20S-PPD. Thus, 20S-PPD appears to induce HSC apoptosis by activating LKB1-AMPK and to be a therapeutic candidate for the prevention or treatment of liver fibrosis.

• Tuberculosis and Respiratory Diseases
• /
• 제60권6호
• /
• pp.631-637
• /
• 2006

배 경: 만성폐쇄성폐질환 환자의 호흡곤란은 일반적으로 폐활량에 반비례하나 유사한 폐기능에서도 서로 다른 호흡곤란을 호소한다. 본 연구는 만성폐쇄성폐질환 환자에서 우심실박출계수와 호흡곤란의 정도와 연관관계가 있는지를 알아보고자 한다. 방 법: 호흡곤란의 정도는 Medical Research Council (MRC) 호흡곤란척도로 분석하였고, MRC 4/5도인 중증군 24명과, MRC 2/3도인 중등증군 16명을 비교 분석하였다. 심전도게이트 일회통과법을 이용한 방사성동위원소 심조영술을 이용하여 우심실 박출계수를 구했으며, 안정시 동맥가스분석 및 폐기능검사를 시행하였다. 결 과: 기저 폐기능에서 잔기량의 예측치 평균이 (%) 중증군에서($210{\pm}87$) 중등증군($160{\pm}27$)에 비해 유의하게 증가되었으나(P < 0.03), 폐활량 및 확산계수 등에서는 유의한 차이가 관찰되지 않았다. 우심실 박출계수(%)는 중증군에서($25{\pm}8$) 중등증군($35{\pm}6$)에 비해 유의하게 감소되었으나(P < 0.001), 동맥혈가스는 두 군 사이에 유의한 차이가 관찰되지 않았다. 다중회귀분석을 통해 우심실 박출계수가 독립적으로 호흡곤란에 영향을 미치는 인자로 밝혀졌다. 결 론: 만성폐쇄성폐질환에서 우심실 박출계수가 호흡곤란의 정도에 영향을 미치는 것으로 보인다.

• 한국통신학회논문지
• /
• 제26권5A호
• /
• pp.846-854
• /
• 2001

본 논문에서는 무선통신로 채널상에 존재하는 가우스 잡음을 포함한 협대역 A급 임펄스 잡음과 나카가미 페이딩 환경에서 하이브리드 DS/FH-CDMA MFSK 시스템의 성능을 비교 분석하고, 성능 개선 기법으로 MRC 다이버시티 수신 기법과 부호화 기법을 동시에 채용함으로써 고려되어진 시스템의 성능을 개선시켰다. 결과에 의하면 임펄스 지수가 강할수록 또한, 페이딩 지수가 작을수록 하이브리드 DS/FH-CDMA 시스템에서는 성능이 더욱 열화됨을 알 수 있었고, 성능 개선 기법으로 BCH 부호화 기법을 채용했을 경우 페이딩 지수가 증가할수록 성능개선의 폭이 큼을 알 수 있었다. 페이딩 지수가 작은 열악한 환경에서는 MRC 다이버시티 수신 기법을 채용하였을 경우 시스템 성능이 우수하였지만, 페이딩 영향이 감소할수록 BCH 부호화 기법을 채용하였을 경우 시스템 성능이 우수함을 알 수 있었다. 또한, 레일리 페이딩 환경에서 각각의 성능개선 기법을 단독으로 채용하였을 경우, 음성서비스 품질($10^{-3}$)에 도달할 수 없지만, BCH 부호화 기법과 MRC 다이버시티를 동시에 채용함으로써 강한 임펄스 잡음 하에서도 24dB 이상에서 음성서비스 기준 오율을 만족하는 성능 개선 효과를 얻을 수 있었고, 페이딩 지수가( $m_{i}$=3) 이상에서는 강한 임펄스 잡음이 부가되어도 21dB에서 $10^{-3}$을 만족하고 28dB 이상에서는 데이터 서비스 기준($10^{-5}$) 오율을 만족하는 우수한 성능 개선 효과를 보임으로써 다이버시티 가지수와 부호화의 이득에 의한 에러 성능이 향상되었다.

• 한국전자파학회논문지
• /
• 제19권5호
• /
• pp.506-514
• /
• 2008

WiBro 시스템과 같은 최근 통신 시스템에서 대역폭 효율을 증가시키기 위해 모든 셀에서 주파수를 재사용하는 경우, 셀 경계에 위치하는 수신기는 인접 셀로부터 오는 간섭 신호로 인해 수신 성능이 열화된다. 본 논문에서는 셀룰러 시스템에서 셀 경계에서의 하향 링크 성능 향상을 위해, 다수 개의 안테나를 가진 단말기에서 활용할 수 있는 수신 방식을 제안한다. 성능 검증을 위하여 인접 셀의 간섭 신호 세기 및 단말기의 안테나 개수의 변화에 따른 유효 신호 대 간섭 잡음비의 화률 밀도 함수와 대역폭 효율을 산출한다. 제안하는 방식은 MRC(Maximum Ratio Combining) 및 SD(Spatial Multiplexing) 방식 대비 유효 신호 대 간섭 잡음비와 대역폭 효율을 큰 폭으로 향상시킴을 분석 결과로 확인할 수 있으며, 실험을 통해 그 결과를 검증한다.