• Title/Summary/Keyword: Life-raft

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Leukotriene Synthesis in Response to A23187 Is Inhibited by Methyl-β-Cyclodextrin in RBL-2H3 Cells

  • You, Hye Jin;Seo, Ji-Min;Moon, Ji-Young;Han, Sung-Sik;Ko, Young-Gyu;Kim, Jae-Hong
    • Molecules and Cells
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    • v.23 no.1
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    • pp.57-63
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    • 2007
  • Leukotrienes (LTs) are produced by several biosynthetic enzymes including cytosolic phospholipase $A_2$ ($cPLA_2$), 5-lipoxygenase (5-LO), and 5-lipoxygenase activating protein (FLAP) in the perinuclear area. In the present study, we showed that pretreatment with methyl-${\beta}$-cyclodextrin (MβCD), a cholesterol-depleting agent, dramatically reduced the synthesis of LTs in response to A23187 in mast cells. A23187-induced LT synthesis was inhibited by pretreatment with M${\beta}$CD, and this effect was reversed when cholesterol was added. In an approach to identifying the $M{\beta}CD$-sensitive protein(s), we observed that FLAP co-localized with flotillin-1, a lipid raft marker protein, in the lipid raft-rich low-density region of sucrose gradients. In addition, electron microscopic analysis revealed that FLAP co-localized with flotillin-1. Together, these results suggest that FLAP is present in cholesterol-rich lipid raft-like domains and that its localization in these domains is critical for LT synthesis.

Molecular Events of Insulin Action Occur at Lipid Raft/Caveolae in Adipocytes (지방세포의 Lipid Raft/Caveolae에서 인슐린의 분자적 작용기전)

  • Bae, Sun-Sik;Yun, Sung-Ji;Kim, Eun-Kyung;Kim, Chi-Dae;Choi, Jang-Hyun;Suh, Pann-Ghill
    • Journal of Life Science
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    • v.17 no.1 s.81
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    • pp.56-63
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    • 2007
  • Insulin stimulates the fusion of intracellular vesicles containing glucose transporter 4 (GLUT4) with plasma membrane in adipocytes and muscle cells. Here we show that adipocyte differentiation results in enhanced insulin sensitivity of glucose uptake. On the other hand, glucose uptake in response to platelet-derived growth factor (PDGF) stimulation was markedly reduced by adipocyte differentiation. Expression level of insulin receptor and caveolin-1 was dramatically increased during adipocyte differentiation. Adipocyte differentiation caused :ilightly enhanced activation of acutely transforming retrovirus AKT8 in rodent T cell lymphoma (Akt) by insulin stimulation. However, activation of Akt by PDGF stimulation was largely reduced. Activation of ERK was not detected in both fibroblasts and adipocytes after stimulation with insulin. PDGF-dependent activation of ERK was reduced by adipocyte differentiation. Insulin-dependent glucose uptake was abrogated by LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, in both fibroblasts and adipocytes. Also disassembly of caveolae structure by $methyl-\beta-cyclodextrin$ caused impairment of Akt activation and glucose uptake. Finally, insulin receptor, Akt, SH2-domain-containing inositol 5-phosphatase 2 (SHIP2), and regulatory subunit of PI3K are localized at lipid raft domain and the translocation was facilitated upon insulin stimulation. Given these results, we suggest that lipid raft provide proper site for insulin action for glucose uptake.

Development of inflatable life raft for small vessel (소형선박용 팽창식 구명뗏목(Inflatable life raft) 개발)

  • Park, Jong O;Lee, Sung Woo
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.1
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    • pp.99-104
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    • 2015
  • Life rafts, which has been used for domestic vessel currently, are fabricated mostly for the ocean-going vessels in accordance with the SOLAS Resolution. Therefore, there is not any small-sized life raft which can be installed on small fishery boat, leisure boat and cargo vessel with those length shorter than 20 meters in our country. However, in many foreign countries, new standards or the small-sized life rafts applicable to those small vessel have been developed according to the standard of ISO 9650. Furthermore, they make their effort to contribute the safety for the life at sea by supply the superior product of life rafts, which have been adopted by light material (i.e. thermoplastic polyurethane, TPU) and economic production process (i.e. heat sealing, radio-frequency welding, RFW), etc. In this paper, the development results of the small-sized life raft, which has been used the lightening material TPU and fabricated by RF-welding method, will be introduced.

Evaluation of Thermal Insulation and Hypothermia for Development of Life Raft (해상 구명정의 단열성능평가 및 저체온증 예측 수치해석 연구)

  • Hwang, Se-Yun;Jang, Ho-Sang;Kim, Kyung-Woo;Lee, Jang-Hyun
    • Journal of Navigation and Port Research
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    • v.39 no.6
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    • pp.485-491
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    • 2015
  • The technology review about risk of hypothermia of victim according to heat transfer characteristic of life raft and sea state can use accident correspondence of standing and sinking of ship. This study studied heat transfer characteristics required for the design of life raft and thermal insulation property analysis and evaluation methods. In addition, it is study for comprehend the risk of hypothermia and suggest analysis result that is experiment of thermal insulation property and body temperature property for decide of prediction the body temperature decline Thermal Analysis apply the finite element analysis method is comprehended the property of heat conductivity, convective effect of sea water and properties changes according to property of insulation material. it measure the heat flux with attach temperature sensor on body in order to comprehend the variation of body temperature with boarding a life raft experiment on a human body. This study validate results by comparing variation of temperature measured from experiment on a body with variation of temperature from finite element analysis model. Also, the criteria of hypothermia was discussed through result of finite element analysis.

Single-Cell-Imaging-Based Analysis of Focal Adhesion Kinase Activity in Plasma Membrane Microdomains Under a Diverse Composition of Extracellular Matrix Proteins (다양한 ECM 조건하에서의 세포막 미세영역 부위 국소접착인산화효소 활성의 단일세포 이미징 기반 분석)

  • Choi, Gyu-Ho;Jang, Yoon-Kwan;Suh, Jung-Soo;Kim, Heon-Su;Ahn, Sang-Hyun;Han, Ki-Seok;Kim, Eunhye;Kim, Tae-Jin
    • Journal of Life Science
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    • v.32 no.2
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    • pp.148-154
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    • 2022
  • Focal adhesion kinase (FAK) is known to regulate cell adhesion, migration, and mechanotransduction in focal adhesions (FAs). However, studies on how FAK activity is regulated in the plasma membrane microdomains according to the composition of extracellular matrix (ECM) proteins are still lacking. A genetically encoded fluorescence resonance energy transfer (FRET)-based biosensor can provide useful information on the activity of intracellular signals with high spatiotemporal resolution. In this study, we analyzed the FAK activities in lipid raft (detergent-resistant membrane) and non-lipid raft (non-detergent-resistant membrane) microdomains using FRET-based membrane targeting FAK biosensors (FAK-Lyn and FAK-KRas biosensors) under four different ECM protein compositions: glass, type 1 collagen, fibronectin, and laminin. Interestingly, FAK activity in response to laminin in a lipid raft microdomain was lower than that in other ECM conditions. Cells subjected to fibronectin showed higher FAK activity in a lipid raft microdomain than that in a non-lipid raft microdomain. Therefore, this study demonstrates that the FAK activity can be distinctively regulated according to the ECM type and the environment of the plasma membrane microdomains.

Comparative Analysis of Src Activity in Plasma Membrane Subdomains via Genetically Encoded FRET Biosensors (유전적으로 암호화된 FRET 바이오센서를 통한 세포막 하위 도메인의 Src 활성 비교 분석)

  • Gyuho Choi;Yoon-Kwan Jang;Jung-Soo Suh;Heonsu Kim;Sanghyun Ahn;Tae-Jin Kim
    • Journal of Life Science
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    • v.33 no.2
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    • pp.191-198
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    • 2023
  • As a member of the focal adhesion complex of the plasma membrane, Src is a nonreceptor tyrosine kinase that controls cell adhesion and motility. However, how Src activity is regulated in the plasma membrane microdomain in response to components of the extracellular matrix (ECM) remains unclear. This study compared and investigated the activity of Src in response to three representative ECM proteins: collagen type 1, fibronectin, and laminin. Genetically encoded FRET-based Src biosensors for plasma membrane subdomains were used. FRET-based biosensors allow the real-time analysis of protein activity in living cells based on their high spatiotemporal resolution. The results showed that Src activity was maintained at a high level under all ECM conditions of the lipid raft, and there was no significant difference between the ECM conditions. In contrast, Src activity was maintained at a low level in the non-lipid raft membrane. In addition, the Src activity of lipid rafts remained significantly higher than that of non-lipid raft regions under the same ECM conditions. In conclusion, this study demonstrates that Src activity can be controlled differently by lipid rafts and non-lipid raft microdomains.

A Study on the Development of Inflatable Life Raft Performance Criteria for Small Fishing Vessels (소형어선용 팽창식 구명뗏목 성능기준 개발에 관한 연구)

  • Kim, Kyung-Woo;Jang, Cheol-Min;Park, Jong-O;Lee, Hee-Joon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.5
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    • pp.558-563
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    • 2014
  • In order to reduce the risk of deaths from hypothermia at sea, this paper suggests the performance criteria of life rafts for small fishing vessels less than 20 m in length. In our country, the life rafts are not used and have no performance criteria. This research compared the performance criteria of the domestic, foreign, international standards, and the performance comparison between foreign life rafts and the user-friendly valise prototype(2 & 4 persons) which is developed by this study. As a result, it is considered to be appropriate that ISO 9650-1 can be applied to the life rafts for offshore fishing vessels while a milder criteria can be applied to the life rafts for coastal fishing vessels.

N-Acetylglucosamine Kinase is Localized to Dendritic Lipid Rafts and Caveolae of Rat Hippocampal Neurons (흰쥐 해마신경세포 가지돌기의 lipid rafts 및 caveolae에서 N-acetylglucosamine kinase의 표현)

  • Moon, Il-Soo
    • Journal of Life Science
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    • v.16 no.6
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    • pp.955-959
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    • 2006
  • A dynamic cycle of addition and removal of O-linked N-acetylglucosamine (O-GlcNAc) at serine and threonine residues is emerging as a key regulator of nuclear and cytoplasmic protein activity. In this work, immunocytochemistry was carried out to investigate the subcellular expression of GlcNAc kinase (NAGK, EC 2.7.1.59) that catalyzes the phosphorylation of GlcNAc to GlcNAc 6-phosphate. Immunostainings of cultured rat hippocampal neurons revealed patchy or punctate distribution of NAGK. When NAGK is doublestained with caveolin-1 or flotillin, markers for caveolae and lipid rafts, respectively, NAGK was co-localized with these markers. These results indicate that most, if not all, of the NAGK immunopunctae represent caveolae and lipid rafts, and suggest NAGK's role in these membrane microdomains.

Analysis of Drift Prediction Formula Used in the Search and Rescue Mission (수색구조 작업에 사용되는 표류지점 추정 공식 분석)

  • 강신영
    • Journal of Korean Port Research
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    • v.12 no.2
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    • pp.373-384
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    • 1998
  • In search and rescue mission the leeway formula based on the field experiments are utilized for the estimation of wind effect on distressed targets. This paper summarized the leeway formula from the available references. In the summary the environmental data collection method and experimental conditions are described along with the formula. Also the formula currently used in CASP of the U.S. Coast Gurard and CANSARP of the Canadian Coast Guard are discussed.

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