• 제목/요약/키워드: Cellular capacity

검색결과 505건 처리시간 0.021초

MicroRNA-203 As a Stemness Inhibitor of Glioblastoma Stem Cells

  • Deng, Yifan;Zhu, Gang;Luo, Honghai;Zhao, Shiguang
    • Molecules and Cells
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    • 제39권8호
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    • pp.619-624
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    • 2016
  • Glioblastoma stem cells (GBM-SCs) are believed to be a subpopulation within all glioblastoma (GBM) cells that are in large part responsible for tumor growth and the high grade of therapeutic resistance that is so characteristic of GBM. MicroRNAs (miR) have been implicated in regulating the expression of oncogenes and tumor suppressor genes in cancer stem cells, including GBM-SCs, and they are a potential target for cancer therapy. In the current study, miR-203 expression was reduced in $CD133^+$ GBM-SCs derived from six human GBM biopsies. MicroRNA-203 transfected GBM-SCs had reduced capacity for self-renewal in the cell sphere assay and increased expression of glial and neuronal differentiation markers. In addition, a reduced proliferation rate and an increased rate of apoptosis were observed. Therefore, miR-203 has the potential to reduce features of stemness, specifically in GBM-SCs, and is a logical target for GBM gene therapy.

Subcellular Distribution of Heavy Metals in Organs of Bivalve Modiolus Modiolus Living Along a Metal Contamination Gradient

  • Podgurskaya, Olga V.;Kavun, Victor Ya.
    • Ocean Science Journal
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    • 제41권1호
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    • pp.43-51
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    • 2006
  • Concentration and distribution of Fe, Zn, Cu, Cd, Mn, Pb, Ni among subcellular fractions (cellular membrane structures and cytosol) and Zn, Cu, Cd among cytoplasmic proteins in the kidney and digestive gland of mussel Modiolus modiolus living along a polymetallic concentration gradient were studied. It was found in the kidney of M. modiolus from contaminated sites that the Fe percent increased in the "membrane" fraction, whereas Zn, Pb, Ni and Mn percent increased in the cytosol compared to the kidney of the control mussel. Note kidney cytosol of M. modiolus from clean and contaminated sites sequestered major parts of Cu and Cd. In the digestive gland of M. modiolus from contaminated sites Fe, Zn, Cd, Mn, Ni percent increased in the "membrane" fraction, whereas Cu, Pb percent increased in the cytosol compared to digestive gland of control mussel. Gel-filtration chromatography shows kidney of M. modiolus contains increased metallothionein-like protein levels irrespective of ambient dissolved metal concentrations. It was shown that the metal detoxification system in the kidney and digestive gland of M. modiolus was efficient under extremely high ambient metal levels. However, under complex environmental contamination in the kidney of M. modiolus, the metal detoxification capacity of metallothionein-like proteins was damaged.

만성폐쇄성폐질환 환자의 영양관리 (Nutritional Management in Patients with Chronic Obstructive Pulmonary Disease)

  • 이관호
    • Journal of Yeungnam Medical Science
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    • 제21권2호
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    • pp.133-142
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    • 2004
  • Chronic obstructive pulmonary disease(COPD) is characterized by a not entirely reversible limitation in the airflow. An airflow limitation is progressive and associated with an abnormal inflammatory response of the lung to gases and harmful particles. In COPD, the weight loss is commonly observed and there is a negative impact on the respiratory as well as skeletal muscle function. The pathophysiological mechanisms that result in weight loss in COPD are not fully understood. However, the mechanisms of weight loss in COPD may be the result of an increased energy expenditure unbalanced by an adequate dietary intake. The commonly occurring weight loss and muscle wasting in COPD patients adversely affect the respiratory and peripheral muscle function, the exercise capacity, the health status, and even the survival rates. Therefore, it is very valuable to include management strategies that the increase energy balance in order to increase the weight and fat free mass. A Better understanding of the molecular and cellular pathological mechanisms of COPD can improve the many new directions for both the basic and clinical investigations. The Nutritional supply is an important components of a multidisciplinary pulmonary rehabilitation program. Future studies combining an exercise program, the role of anabolic steroids, nutritional individualization, a more targeted nutritional therapy, and the development of new drugs including anti-cytokines is needed for the effective management of COPD.

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WCDM 시스템에서 하향 링크 전력의 동적 할당 (Dynamic Allocation of Downlink Power for WCDMA Systems)

  • 김영주;최인한;강성호;이인성
    • 대한전자공학회논문지TC
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    • 제44권10호
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    • pp.1-7
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    • 2007
  • WCDMA 시스템에서 하향링크 저력할당은 치국(置局) 셀 용량 영역, 시스템 성능에 직접적인 영향을 준다. 제한된 송신전력 최대의 가입자를 수용하기 위해서 하향링크 전력을 최소로 유지하면서 셀 사용자의 요구 신호 대 잡음비를 만족시켜야 한다. 본 논문에서는 시스템에 접속하여 통화 중인 사용자의 수에 따라 하향링크 전력의 할당이 가변적이어야 함을 수식으로 증명하고, 동적 하향 링크 전력 할당 방법을 채택할 것을 제안한다. 또한 상향 및 하향 링크가 평형을 이루기 위한 파일롯 신호 및 단말기 전송전력 세기를 분석한다.

적응 간섭 제거 시스템을 위한 상관도를 적용한 적응적 궤환 간섭 제거 알고리즘 (Adaptive Feedback Interference Cancellation Algorithm Using Correlations for Adaptive Interference Cancellation System)

  • 한용식;양운근
    • 한국전자파학회논문지
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    • 제21권4호
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    • pp.427-432
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    • 2010
  • 셀룰러 시스템에서의 음영 지역 해소 및 전송 용량 증대를 위해 중계기의 중요성은 계속적으로 증가하고 있다. 그러나 RF 중계기는 중계된 전송 신호의 일부가 궤환되어 다시 수신 안테나에 수신되는 궤환 간섭 신호가 발생한다. 이런 문제를 해결하기 위하여 본 논문에서는 RF 중계기의 성능 개선을 위해 상관도를 적용한 Sign-Sign LMS(Least Mean Square)를 제안하였다. 기존 알고리즘의 제곱된 에러를 최소화하기 위해 가중치 벡터는 입력 신호와 오차 신호의 부호에 취하고, 이를 활용하여 갱신된다. 제안된 간섭 제거기는 기존 방식과 비교하여 MSE(Mean Square Error) 측면에서 최대 10 dB의 성능 이득을 가진다.

Cyclamen Exerts Cytotoxicity in Solid Tumor Cell Lines: a Step Toward New Anticancer Agents?

  • Yildiz, Mustafa;Bozcu, Hakan;Tokgun, Onur;Karagur, Ege Riza;Akyurt, Oktay;Akca, Hakan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.5911-5913
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    • 2013
  • Cyclamen coum is a traditional medicinal plant in the Turkey. Its anticancer properties and whether cyclamen extract induces any cytotoxicity in solid cancer cell lines have not been thoroughly investigated previously. Therefore we examined cytotoxic effects on cervical cells; HeLa and non small cell lung cancer cell, H1299, lines; Cyclamen extract induced cellular death of both HeLa and H1299 cells in a dose dependent manner. We also analyzed the capacity of cyclamen extract to induce apoptosis by the TUNEL method. Here, for the first time we report that the extract of Cyclamen coum, an endemic plant for Turkey, Bulgaria, Georgia and the Middle East can induce cytotoxicity via apoptosis in HeLa and H1299 cells. These results imply that cyclamen extract can be further analyzed to potentially find novel anticancer compounds.

Overexpression of TTRAP inhibits cell growth and induces apoptosis in osteosarcoma cells

  • Zhou, Caihong;Shen, Qi;Xue, Jinglun;Ji, Chaoneng;Chen, Jinzhong
    • BMB Reports
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    • 제46권2호
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    • pp.113-118
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    • 2013
  • TTRAP is a multi-functional protein that is involved in multiple aspects of cellular functions including cell proliferation, apoptosis and the repair of DNA damage. Here, we demonstrated that the lentivirus-mediated overexpression of TTRAP significantly inhibited cell growth and induced apoptosis in osteosarcoma cells. The ectopic TTRAP suppressed the growth and colony formation capacity of two osteosarcoma cell lines, U2OS and Saos-2. Cell apoptosis was induced in U2OS cells and the cell cycle was arrested at G2/M phase in Saos-2 cells. Exogenous expression of TTRAP in serum-starved U2OS and Saos-2 cells induced an increase in caspase-3/-7 activity and a decrease in cyclin B1 expression. In comparison with wild-type TTRAP, mutations in the 5'-tyrosyl-DNA phosphodiesterase activity of TTRAP, in particular $TTRAP^{E152A}$, showed decreased inhibitory activity on cell growth. These results may aid in clarifying the physiological functions of TTRAP, especially its roles in the regulation of cell growth and tumorigenesis.

Comparison of Labyrinthulid Strains L4 and L75 by Fatty Acid Composition and Characteristics

  • Dang, Diem Hong;Nakahara, Toro
    • Fisheries and Aquatic Sciences
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    • 제11권3호
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    • pp.149-158
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    • 2008
  • Labyrinthulids are unicellular heterotrophic marine microalgae. Two labyrinthulid strains, L4 and L75, which produce generous amounts of polyunsaturated fatty acids(PUFAs), were isolated from leaves floating in the coastal areas of Quang Ninh province, Vietnam, and Fukuoka Prefecture, Japan, respectively. Both strains had spindle-shaped cells surrounded by ectoplasmic networks. Numerous oil bodies were observed in each cell, mostly in the vicinity of cell membranes. When soybean oil or soybean lecithin was used as a carbon source with peptone as a nitrogen source, the proportion of PUFAs reached 25-30% and 50-56% for L4 and L75, respectively. After 14 days of growth at $25^{\circ}C$, L4 produced 0.3 mg PUFAs/g-agar in PYA-SBO medium and 0.6 mg PUFAs/g-agar in PYA-SBL medium. In comparison, L75 produced 0.2 mg PUFAs/g-agar in both types of media. The differences between the two strains included changes in cellular morphology and the capacity for attaching tightly to fibers when cultured in liquid PYA medium containing 2% SBL. In addition, when the strains were grown under the same conditions, L4 had a higher growth rate and produced more PUFAs than L75.

The Effects of Acute Osmotic Stress on Innate Immunity of Nile Tilapia (Oreochromis niloticus)

  • Choi, Sang-Hoon;Park, Kwan-Ha
    • Fisheries and Aquatic Sciences
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    • 제13권4호
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    • pp.343-349
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    • 2010
  • The effects of osmotic stress on the non-specific immune response of Nile tilapia, Oreochromis niloticus, were investigated. Osmoregulatory mechanism of tilapia has been studied, but less information is available about innate immune response of O. niloticus faced with hyperosmolality. Acute osmotic stress was elicited by transferring tilapia from freshwater (FW) to 24 psu seawater (SW). Non-specific immune parameters including lysozyme activities of plasma and head kidney (HK), alternative complement pathway (ACP) activity in plasma, phagocytic capacities of spleen and HK immune cells, and respiratory burst activity of immune cells in both HK and spleen were analyzed. Lysozyme activities were increased at 1 h and 30 h after transfer to SW, but decreased at 10 h after SW transfer. Conversely, ACP activity increased 10 h after SW transfer. Phagocytic capacity increased slightly at 1 h and 5 h after SW transfer, and respiratory burst activity showed an increase in superoxide release at 10 h after SW transfer. Taken together, these results indicate that the exposure of tilapia to hyperosmotic conditions has immunostimulatory effects on cellular and humoral immune reactions.

레일리 페이딩 채널에서의 이중직교 신호에 대한 다중심볼 검파 (Multi-symbol detection for biorthogonal signals over rayleigh fading channels)

  • 엄의식;윤순영;이황수
    • 한국통신학회논문지
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    • 제22권1호
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    • pp.30-39
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    • 1997
  • 본 논문은 CDMA 셀룰라 역방향 접속 시스템의 성능개선을 위하여 이중직교 신호에 대한 다중심볼 검파방식을 제안하고, 이에 대한 성능해석과 컴퓨터 모의실험을 수행한다. 이 방식은 기존의 심볼단위 비동기 검파대신 복잡도를 줄인 근사 MLSE에 의해 다중심볼로 구성된 복조 데이터와 채널을 동시에 예측한다. 이 방식은 또한 주어진 심볼의 워드수 M에 대해 관측하는 다중심볼 길이 N을 적절히 선택할 때 채널의 예측이 없이도 이상적인 동기검파 방식에 근접한 오류성능을 얻게 해준다. 특히 매우 의미 있는 사항은 이 방식을 CDMA 역방향 접속 시스템에 적용할 때 요구되는 평균 비트당 신호대 잡은 전력비 ${\gamma}_{b}$를 약 1.4dB정도 줄일 수 있어 38% 정도의 용량이 증가된다.

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