• 방사선산업학회지
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• 제3권1호
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• pp.25-29
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• 2009

Microarrays can be used to screen thousands of binding events in a parallel and high throughput fashion and are of major importance in disease diagnosis and drug discovery. The use of radioisotope is conventionally regarded as one of the most sensitive detection methods. Atherosclerosis is a common disorder affecting arterial blood vessels. It happens when fat, cholesterol, and other substances made in the arterial blood vessels form a hard substances called plaque. Lipoprotein-associated phospholipase $A_2$ ($Lp-PLA_2$), a phospholipase $A_2$ enzyme, is used as a marker for cardiac disease. The detection of $Lp-PLA_2$ was accomplished by using radioactive [$^3H-acetyl$] PAF as a substrate and a feasibility study on RI biochip application to detection of $Lp-PLA_2$, a risk factors of atherosclerosis was performed. Inhibitive activity of a native plant extract was also determined by using the RI biochip. It was found to be applicable to a high-throughput screening of inhibitors for developing atherosclerosis therapeutic agents.

• The Korean Journal of Physiology and Pharmacology
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• 제27권1호
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• pp.75-84
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• 2023

This study aimed to observe the protective effect of momordicine I, a triterpenoid compound extracted from momordica charantia L., on isoproterenol (ISO)-induced hypertrophy in rat H9c2 cardiomyocytes and investigate its potential mechanism. Treatment with 10 μM ISO induced cardiomyocyte hypertrophy as evidenced by increased cell surface area and protein content as well as pronounced upregulation of fetal genes including atrial natriuretic peptide, βmyosin heavy chain, and α-skeletal actin; however, those responses were markedly attenuated by treatment with 12.5 ㎍/ml momordicine I. Transcriptome experiment results showed that there were 381 and 447 differentially expressed genes expressed in comparisons of model/control and momordicine I intervention/model, respectively. GO enrichment analysis suggested that the anti-cardiomyocyte hypertrophic effect of momordicine I may be mainly associated with the regulation of metabolic processes. Based on our transcriptome experiment results as well as literature reports, we selected glycerophospholipid metabolizing enzymes group VI phospholipase A₂ (PLA2G6) and diacylglycerol kinase ζ (DGK-ζ) as targets to further explore the potential mechanism through which momordicine I inhibited ISO-induced cardiomyocyte hypertrophy. Our results demonstrated that momordicine I inhibited ISO-induced upregulations of mRNA levels and protein expressions of PLA2G6 and DGK-ζ. Collectively, momordicine I alleviated ISO-induced cardiomyocyte hypertrophy, which may be related to its inhibition of the expression of glycerophospholipid metabolizing enzymes PLA2G6 and DGK-ζ

• Food Science and Biotechnology
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• 제15권5호
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• pp.799-804
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• 2006

Ingestion of green tea has been shown to decrease prostaglandin $E_2$ levels in human colorectum, suggesting that tea constituents modulate arachidonic acid metabolism. In the present study, we investigated the effects of four purified green tea catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG), and (-)-epicatechin-3-gallate (ECG), on the catalytic activity of cytosolic phospholipase $A_2$ ($cPLA_2$) and release of arachidonic acid and its metabolites from intact cells. At $50\;{\mu}M$, EGCG and ECG inhibited $cPLA_2$ activity by 19 and 37%, respectively, whereas EC and EGC were less effective. The inhibitory effects of these catechins on arachidonic acid metabolism in intact cells were much more pronounced. At $10\;{\mu}M$, EGCG and ECG inhibited the release of arachidonic acid and its metabolites by 50-70% in human colon adenocarcinoma cells (HT-29) and human esophageal squamous carcinoma cells (KYSE-190 and 450). EGCG and ECG also inhibited arachidonic acid release induced by A23187, a calcium ionophore, in both HT-29 and KYSE-450 cell lines by 30-50%. The inhibitory effects of green tea catechins on $cPLA_2$ and arachidonic acid release may provide a possible mechanism for the prevention of human gastrointestinal inflammation and cancers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1057-1073
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• 2015

In this paper, we consider cooperative D2D communications in cellular networks. More precisely, a cellular user leases part of its spectrum to facilitate the D2D communication with a goal of improving the energy efficiency of a D2D pair. However the D2D pair is untrusted to the cellular user, such resource sharing may result in the information of this cellular user unsecured. In order to motivate the cellular user's generosity, this D2D pair needs to help the cellular user maintain a target secrecy rate. To address this issue, we formulate a joint spectrum and power allocation problem to maximize the energy efficiency of the D2D communication while guaranteeing the physical layer security of the cellular user. Then, a theorem is proved to indicate the best resource allocation strategy, and accordingly, an algorithm is proposed to find the best solution to this resource allocation problem. Numerical results are finally presented to verify the validity and effectiveness of the proposed algorithm.

• 분석과학
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• 제27권6호
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• pp.277-283
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• 2014

한외여과법을 이용하여 봉독의 알러지 원인성분인 $PLA_2$를 제거하기 위하여 압력, 농도, 분자크기의 영향을 조사하였다. 봉독의 주요성분 분자량을 바탕으로 한외여과막의 투과크기를 선정하고 농도와 압력을 달리하였다. 그 결과, melittin과 apamin 함량은 유지되면서 $PLA_2$를 제거하는 최적조건(1 mg/mL, 20 psi, 10,000 dalton)을 찾았으며, 이를 HPLC와 SDS-PAGE로 확인하였다.

• Journal of Ginseng Research
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• 제39권3호
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• pp.189-198
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• 2015

Background: Antiallergic effect of 20(S)-protopanaxatriol (PPT), an intestinal metabolite of ginseng saponins, was investigated in guinea pig lung mast cells and mouse bone marrow-derived mast cells activated by a specific antigen/antibody reaction. Methods: Increasing concentrations of PPT were pretreated 5 min prior to antigen stimulation, and various inflammatory mediator releases and their relevant cellular signaling events were measured in those cells. Results: PPT dose-dependently reduced the release of histamine and leukotrienes in both types of mast cells. Especially, in activated bone marrow-derived mast cells, PPT inhibited the expression of Syk protein, cytokine mRNA, cyclooxygenase-1/2, and phospholipase $A_2$ ($PLA_2$), as well as the activities of various protein kinase C isoforms, mitogen-activated protein kinases, $PLA_2$, and transcription factors (nuclear factor-${\kappa}B$ and activator protein-1). Conclusion: PPT reduces the release of inflammatory mediators via inhibiting multiple cellular signaling pathways comprising the $Ca^{2+}$ influx, protein kinase C, and $PLA_2$, which are propagated by Syk activation upon allergic stimulation of mast cells.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.4835-4855
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• 2015

TV white space (TVWS) is showing promise to become the first widespread practical application of cognitive technology. In fact, regulators worldwide are beginning to allow access to the TV band for secondary users, on the provision that they access the geolocation database. Device-to-device (D2D) can improve the spectrum efficiency, but large-scale D2D communications that underlie TVWS may generate undesirable interference to TV receivers and cause severe mutual interference. In this paper, we use an established geolocation database to investigate the power allocation problem, in order to maximize the total sum throughput of D2D links in TVWS while guaranteeing the quality-of-service (QoS) requirement for both D2D links and TV receivers. Firstly, we formulate an optimization problem based on the system model, which is nonconvex and intractable. Secondly, we use an effective approach to convert the original problem into a series of convex problems and we solve these problems using interior point methods that have polynomial computational complexity. Additionally, we propose an iterative algorithm based on the barrier method to locate the optimal solution. Simulation results show that the proposed algorithm has strong performance with high approximation accuracy for both small and large dimensional problems, and it is superior to both the active set algorithm and genetic algorithm.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2489-2493
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• 2012

A new fluorescent system (acridine/RTIL hybrid gel) confined in the 3D micro-structure of a poly(lactic acid) membrane were prepared from 1-butyl-3-methylimidazolium-based ionic liquids ([bmim]X (X = $SbF_6$, $NTf_2$, Cl); RTILs), poly(lactic acid) (PLA), and acridine via the sol-gel route. SEM images showed that, in the presence of [bmim]$SbF_6$ and [bmim]$NTf_2$, 3D-ly paticulated structures were created inside the PLA membranes and acridine/RTIL hybrid gels were confined in gabs of particulates. However, the use of [bmim]Cl induced the formation of a 3D-ly porous structure containing the hybrid gel of acridine/[bmimCl in the micropores. The three fluorescent systems exhibited different fluorescence behaviors (fluorescence maximum and intensity) depending on the C2-H acidity scale of the RTILs (or their anion type). Acridine gels hybridized with [bmim]$SbF_6$ and [bmim]$NTf_2$ showed blue fluorescence with relative high intensity, whereas the hybrid gel with [bmim]Cl exhibited almost no fluorescence under dry conditions. However, the acridine/[bmim]Cl hybrid system in the micro-porous PLA membrane started to emit fluorescent light under humid conditions and showed a possible response, indicating that it could be applied as a humidity sensor.

• Toxicological Research
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• 제31권1호
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• pp.33-40
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• 2015

Bee venom (BV) has long been used in traditional Eastern and Western medicine for chronic inflammation, pain and skin therapy. Human exposure to BV, however, often causes unwanted adverse effects and is even fatal in some cases. Phospholipase $A_2$ ($PLA_2$) of BV is now suspected to play a key role in these adverse effects. We investigated the potential use of $PLA_2$-free bee venom (PBV) as a replacement for BV in cosmetic products. PBV prepared by molecular weight cut-off ultrafiltration exhibits a superior profile in comparison with regular BV, by inhibiting elastase activity and suppressing the induction of nitric oxide (NO) and metalloproteinase-9 (MMP-9), while retaining the effects of cell proliferation and protection against ultraviolet B (UVB)-induced damage in human dermal fibroblast cells. PBV thus appears to be more promising than BV as a cosmetic ingredient with a reduced potential for adverse reactions in the recipient.

• Tuberculosis and Respiratory Diseases
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• 제68권6호
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• pp.334-344
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• 2010

Background: Based on the known immunoregulatory functions of moxifloxacin on phagocytes, the therapeutic effect of moxifloxacin on oleic acid (OA)-induced acute lung injury (ALI) was investigated. Methods: Moxifloxacin (10 mg/kg) was given to male Sprague-Dawley rats that had been given oleic acid (OA, $30{\mu}L$) intravenously. Five hours after OA injection, parameters demonstrating ALI were assessed to measure the effects of moxifloxacin on acute lung injury. Results: The pathological findings of OA-induced ALI's was diminished by moxifloxacin. Through ultrastructural and $CeCl_3$ EM histochemistry, moxifloxacin was confirmed to be effective in decreasing oxidative stress in the lung as well. Indices of ALI, such as lung weight/body weight ratio, protein content in bronchoalveolar lavage fluid, and lung myeloperoxidase were decreased by moxifloxacin. In diaminobenzidine immunohistochemistry, fluorescent immunohistochemistry, and Western blotting of the lung, moxifloxacin had decreased the enhanced expression of secretory phospholipase $A_2$ ($sPLA_2$) by OA. Conclusion: We concluded that moxifloxacin was effective in lessening acute inflammatory pulmonary edema caused by OA, by inhibiting the neutrophilic respiratory burst, which was initiated by the activation of $sPLA_2$.