• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1259-1264
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• 2014

Hydrogen is in the world limelight for future energy source, and it has been already used in various industry fields including aerospace. The extremely fine molecule of the hydrogen can be easily leaked from tiny size of the crack on the surface of transporting pipes or storage tanks, and it could bring on awfully terrible disaster. In this study, Laser-Induced Breakdown Spectroscopy (LIBS) was employed to develope a reliable detection scheme for a small quantity of hydrogen leakage. Effect of three different metal substrates (i.e. Al, Cu, SUS) on plasma generation and the intensity of the hydrogen atomic signal was investigated, and the surface damage of the substrates due to repetitive laser shots was observed using Scanning electron microscope. It was also evaluated how the surface damage could distort the atomic signal. The intensity of the atomic signal was found to be the strongest, and the signal distortion due to the surface damage was approximately $100W/m^2$ lower when Al was used for the substrate.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.5
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• pp.450-458
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• 2009

The range-dependent overlap factor of a lidar system can be determined experimentally if a Raman backscatter signal by molecule is measured in addition to the usually observed elastic backscatter signal, which consists of a molecular component and a particle component. The direct determination of the overlap profile is presented and applied to a lidar measurement according to variation of telescope field-of-view and distance between telescope and transmitting laser. The retrieval of extinction coefficient by Raman method can generate high errors for heights below planetary boundary layer if the overlap effect is ignored. The overlap correction method presented here has been successfully applied to experimental data obtained in Gwangju, Korea.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1579-1583
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• 2013

Intercellular adhesion molecule-1 (ICAM-1) is a member of the immunoglobulin superfamily, its main function being to participate in recognition and adhesion between cells. ICAM-1 is considered closely related to occurrence, development, metastasis and invasion process of hepatocellular carcinoma (HCC). A variety of inflammatory cytokines and stimulus affect its expression through the nuclear factor-kappa B (NF-${\kappa}B$) signal transduction pathway. In the initial stage of inflammation, hepatocirrhosis and tumor development, ICAM-1 is expressed differently, and has varied effects on different cells to promote occurrence of malignancy and metastasis. ICAM-1 has diagnostic significance for AFP-negative or suspected HCC, and may be a prognositic significance. It is thus widely used in studies as a biomarker which reflects cancer cells metastasis as well as curative effect of drugs. Many new treatments of HCC may be based on the effects of ICAM-1 on different levels of function.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.451-459
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• 2024

Apoptosis signal-regulating kinase 1 (ASK1) is an upstream signaling molecule in oxidative stress-induced responses. Because oxidative stress is involved in asthma pathogenesis, ASK1 gene deficiency was investigated in animal models of allergic asthma. However, there is no study to investigate whether ASK1 inhibitors could be applied for asthma to date. Selonsertib, a potent and selective ASK1 inhibitor, was applied to BALB/c mice of an ovalbumin (OVA)-induced allergic asthma model. Selonsertib suppressed antigen-induced degranulation of RBL-2H3 mast cells in a concentration-dependent manner. The administration of selonsertib both before OVA sensitization and OVA challenge significantly reduced airway hyperresponsiveness, and suppressed eosinophil numbers and inflammatory cytokine levels in the bronchoalveolar lavage fluid. Histopathologic examination elucidated less inflammatory responses and reduced mucin-producing cells around the peribronchial regions of the lungs. Selonsertib also suppressed the IgE levels in serum and the protein levels of IL-13 in the bronchoalveolar lavage fluid. These results suggest that selonsertib may ameliorate allergic asthma by suppressing immune responses and be applicable to allergic asthma.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.133-137
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• 2013

Vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), P- and E-selectin play a pivotal role for initiation of atherosclerosis. Ginsenoside, a class of steroid glycosides, is abundant in Panax ginseng root, which has been used for prevention of illness in Korea. In this study, we investigated the mechanism(s) by which ginsenoside Rg2 may inhibit VCAM-1 and ICAM-1 expressions stimulated with lipopolysaccharide (LPS) in human umbilical vein endothelial cell (HUVEC). LPS increased VCAM-1 and ICAM-1 expression. Ginsenoside Rg2 prevented LPS-mediated increase of VCAM-1 and ICAM-1 expression. On the other hand, JSH, a nuclear factor kappa B (NF-${\kappa}B$) inhibitor, reduced both VCAM-1 and ICAM-1 expression stimulated with LPS. SB202190, inhibitor of p38 mitogen-activated protein kinase (p38 MAPK), and wortmannin, phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, reduced LPS-mediated VCAM-1 but not ICAM-1 expression. PD98059, inhibitor of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) did not affect VCAM-1 and ICAM-1 expression stimulated with LPS. SP600125, inhibitor of c-Jun N-terminal kinase (JNK), reduced LPS-mediated ICAM-1 but not VCAM-1 expression. LPS reduced IkappaB${\alpha}$ ($I{\kappa}B{\alpha}$) expression, in a time-dependent manner within 1 hr. Ginsenoside Rg2 prevented the decrease of $I{\kappa}B{\alpha}$ expression stimulated with LPS. Moreover, ginsenoside Rg2 reduced LPS-mediated THP-1 monocyte adhesion to HUVEC, in a concentration-dependent manner. These data provide a novel mechanism where the ginsenoside Rg2 may provide direct vascular benefits with inhibition of leukocyte adhesion into vascular wall thereby providing protection against vascular inflammatory disease.

• IMMUNE NETWORK
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• v.2 no.1
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• pp.35-40
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• 2002

Background: CTLA-4 (Cytotoxic T Lymphocyte associated Antigen 4, CD152) has been known as a homologue of CD28, an accessory molecule providing a key costimulatory signal for successful antigen-driven activations of T lymphocyte. Most of biochemical and cell biological characteristics of the CD152 protein remain unknown while those of CD28 have been characterized in detail. Methods: In this study CD152 expression in both $CD4^+$ and $CD8^+$ PBLs was studied by using flow cytometry. And intracellular CD152 multiprotein complex was purified and used for generating antibodies recognizing proteins composing of intracellular CTLA-4 multi protein complex. Results: Level of surface expression of this molecule was peaked at 2 days of PHA stimulation in flow cytometric analysis. 40~45% of PHA blast cells were $CD152^+$ in both of two subsets at this stage and the level of expression were equivalent in both two subsets. Contrary to this surface expression, intracellular expression was peaked at day 3 and it was preferentially induced in $CD8^+$ cells and about 60% of $CD8^+$ cells were $CD152^+$ at this stage. High molecular weight (>350 kD) intacellular CD152 protein complex purified by using preparative electrophoresis were immunized into rabbits and then 3 different anti-P34PC4, anti-P34PC7 and anti-P34PC8 antibodies were obtained. Using these 3 antibodies two unknown antigens associated with intracellular CD152 multiprotein complex were found and their molecular weights were 54 kD and 75 kD, respectively. Among these, the former was present as 110 kD homodimer in non-reducing condition. Conclusion: It seemed that 34 kD intracellular CD152 molecule forms high molecular weight multiprotein complex at least with 2 proteins of 75 kD monomer and 110 kD homodimer.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.783-790
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• 2007

The immobilization of proteins and their molecular interactions on various polymer-modified glass substrates [i.e. 3-aminopropyltriethoxysilane (APTS), 3-glycidoxypropyltrimethoxysilane (GPTS), poly (ethylene glycol) diacrylate (PEG-DA), chitosan (CHI), glutaraldehyde (GA), 3-(trichlorosilyl)propyl methacrylate (TPM), 3'-mercaptopropyltrimethoxysilane (MPTMS), glycidyl methacrylate (GMA) and poly-l-lysine (PL).] for potential applications in a nanoarray protein chip at the single-molecule level was evaluated using prismtype dual-color total internal reflection fluorescence microscopy (dual-color TIRFM). A dual-color TIRF microscope, which contained two individual laser beams and a single high-sensitivity camera, was used for the rapid and simultaneous dual-color detection of the interactions and colocalization of different proteins labeled with different fluorescent dyes such as Alexa Fluor® 488, Qdot® 525 and Alexa Fluor® 633. Most of the polymer-modified glass substrates showed good stability and a relative high signal-to-noise (S/N) ratio over a 40-day period after making the substrates. The GPTS/CHI/GA-modified glass substrate showed a 13.5-56.3% higher relative S/N ratio than the other substrates. 1% Top-Block in 10 mM phosphate buffered saline (pH 7.4) showed a 99.2% increase in the blocking effect of non-specific adsorption. These results show that dual-color TIRFM is a powerful methodology for detecting proteins at the single-molecule level with potential applications in nanoarray chips or nano-biosensors.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.118-124
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• 2013

Mast cells is the key effector cells for IgE-mediated allergic responses. In this study, we investigated whether Rhus trichocarpa extract (RT) inhibited IgE-mediated allergic responses in mast cells and an allergic animal model. We further tried to find its mechanism of action in mast cells. We found that RT suppressed antigen-stimulated degranulation and production of TNF-${\alpha}$ and IL-4 in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. As the mechanism of action of RT, it inhibited the activation of spleen tyrosine kinase (Syk), a pivotal signaling molecule for activation of mast cells and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. RT also suppressed the activation of mitogen-activated protein (MAP) kinases and Akt. The current results demonstrated for the first time that RT has the anti-allergic effect through inhibiting degranulation and secretion of cytokines by suppression of Syk in antigen-stimulated mast cells. Therefore, RT might be useful for allergic diseases.

• Journal of Plant Biotechnology
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• v.4 no.1
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• pp.1-6
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• 2002

Plants have developed a sophisticated battery of defence responses to protect themselves against attempted pathogen ingress. Manipulation of these defence mechanisms may provide significant opportunities for crop improvement. While plant resistance genes have had a long service history in plant breeding, they possess significant limitations. Recent advances are now providing significant insights into strategies designed to increase the field durability of this class of genes. Hypersensitive cell death is a common feature underlying the deployment of plant defence responses against biographic pathogens. In contrast, necrotrophic pathogens actively kill plant cells. Recently, transgenic plants have been developed that either promote or suppress cell death, providing resistance against either biotrophic or necrotrophic pathogens respectively. Methyl-jasmonate is a key signalling molecule in the establishment of resistance against some fungal pathogens. Increasing the concentration of this molecule in plant cells has been shown to increase resistance against Botrytis cineria, without significantly imparting plant growth or development. Due to the multifarious infection strategies employed by plant pathogens, how-ever, it is unlikely a single commercial product will prove a panacea for global disease control. Future stategies will more likely entail an integrated disease management approach.

• BMB Reports
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• v.46 no.7
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• pp.352-357
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• 2013

Atherosclerosis, which manifests as acute coronary syndrome, stroke, and peripheral arterial diseases, is a chronic inflammatory disease of the arterial wall. Prunella vulgaris, a perennial herb with a worldwide distribution, has been used as a traditional medicine in inflammatory disease. Here, we investigated the effects of P. vulgaris ethanol extract on TNF-${\alpha}$-induced inflammatory responses in human aortic smooth muscle cells (HASMCs). We found that P. vulgaris ethanol extract inhibited adhesion of monocyte/macrophage-like THP-1 cells to activated HASMCs. It also decreased expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and ROS, No production in TNF-${\alpha}$-induced HASMCs and reduced NF-${\kappa}B$ activation. Furthermore, P. vulgaris extract suppressed TNF-${\alpha}$-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK). These results demonstrate that P. vulgaris possesses anti-inflammatory properties and can regulate TNF-${\alpha}$-induced expression of adhesion molecules by inhibiting the p38 MAPK/ERK signaling pathway.