• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.4
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• pp.295-302
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• 2016

Background: Reactive oxygen species play critical roles in homeostasis and cell signaling. Dexmedetomidine, a specific agonist of the ${\alpha}2$-adrenoceptor, has been commonly used for sedation, and it has been reported to have a protective effect against oxidative stress. In this study, we investigated whether dexmedetomidine has a protective effect against $H_2O_2$-induced oxidative stress and the mechanism of $H_2O_2$-induced cell death in normal human fetal osteoblast (hFOB) cells. Methods: Cells were divided into three groups: control group-cells were incubated in normoxia without dexmedetomidine, hydrogen peroxide ($H_2O_2$) group-cells were exposed to $H_2O_2$ ($200{\mu}M$) for 2 h, and Dex/$H_2O_2$ group-cells were pretreated with dexmedetomidine ($5{\mu}M$) for 2 h then exposed to $H_2O_2$ ($200{\mu}M$) for 2 h. Cell viability and apoptosis were evaluated. Osteoblast maturation was determined by assaying bone nodular mineralization. Expression levels of bone-related proteins were determined by western blot. Results: Cell viability was significantly decreased in the $H_2O_2$ group compared with the control group, and this effect was improved by dexmedetomidine. The Hoechst 33342 and Annexin-V FITC/PI staining revealed that dexmedetomidine effectively decreased $H_2O_2$-induced hFOB cell apoptosis. Dexmedetomidine enhanced the mineralization of hFOB cells when compared to the $H_2O_2$ group. In western blot analysis, bone-related protein was increased in the Dex/$H_2O_2$ group. Conclusions: We demonstrated the potential therapeutic value of dexmedetomidine in $H_2O_2$-induced oxidative stress by inhibiting apoptosis and enhancing osteoblast activity. Additionally, the current investigation could be evidence to support the antioxidant potential of dexmedetomidine in vitro.

• BMB Reports
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• v.48 no.3
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• pp.178-183
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• 2015

Dendritic cells play an important role in determining whether na${\ddot{i}}$ve T cells mature into either Th1 or Th2 cells. We determined whether heat-shock protein X (HspX) purified from Mycobacterium tuberculosis regulates the Th1/Th2 immune response in an ovalbumin (OVA)-induced murine model of asthma. HspX increased interferon-gamma, IL-17A, -12 and transforming growth factor (TGF)-${\beta}$ production and T-bet gene expression but reduced IL-13 production and GATA-3 gene expression. HspX also inhibited asthmatic reactions as demonstrated by an increase in the number of eosinophils in bronchoalveolar lavage fluid, inflammatory cell infiltration in lung tissues, airway luminal narrowing, and airway hyper-responsiveness. Furthermore, HspX enhanced OVA-induced decrease of regulatory T cells in the mediastinal lymph nodes. This study provides evidence that HspX plays critical roles in the amelioration of asthmatic inflammation in mice. These findings provide new insights into the immunotherapeutic role of HspX with respect to its effects on a murine model of asthma.

• Toxicological Research
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• v.11 no.1
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• pp.1-8
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• 1995

Fumonisins are a family of mycotoxins produced by the fungus Fusarium moniliforme which is a common contaminant in corn. Fumonisins are potent inhibitors of sphingosine and sphinganine N-acyltransferase (ceramide synthase), key enzymes in sphingolipid metabolism. The purpose of this study was to provide the evidence that the elevated levels of free sphingoid bases (primarily sphinganine) and depletion of complex sphingolipids were closely related to the inhibition of cell growth in LLC-$PK_1$ cells exposed to fumonisin $B_1$$(\leq 35 {\mu}M)$. Concentrations of fumonisin $B_1$ between 10 and $35 {\mu}M$ were known to inhibit cell growth without cytotoxicity in $LLC-PK_1$ cells (Yoo et al. Toxicol. Appl. Pharmacol. 114, 9-15, 1992). Cells exposed to 35$\mu M$ fumonisin B$_1$ for 48 and 72 hr developed a fibroblast-like (elongated and spindle-shaped) appearance and were less confluent than normal cells. At between 24 and 48 hr after exposure to fumonisin $B_1$ cells were beginning to show the inhibition of cell growth and at 72 hr the number of viable cells in fumonisin-treated cultures was about 50% of concurrent control cultures. During the 24 hr lag period preceding inhibition of cell growth, the free sphinganine levels in cells exposed to $35 {\mu}M$ fumonisin $B_1$ were highly elevated (approximately 230 fold higher than normal cells). The elevated levels of free sphinganine were $435\pm14$$pmoles/{10^6}$ cells at 48 hr and approximately TEX>$333\pm11$$pmoles/{10^6}$ cells in cells exposed to $35{\mu}M$ fumonisin$B_1$ at 72 hr, while the levels of free sphinganine in normal cells were less than 2$pmoles/{10^6}$ cells. Under the same condition, depletion of intracellular complex sphingolipids as a consequence of fumonisin inhibition of de novo sphingolipid biosynthesis and turnover pathway was appeared. Content of free sphingold bases in dividing cells was more elevated than in confluent cells at 24-48 hr after cells were exposed to $20{\mu}M$ fumonisin $B_1$. The dividing cells were showing the inhibition of cell growth at 48-72 hr and $20{\mu}M$ fumonisin $B_1$. The results of this study support the hypothesis that the inhibition of cell growth is very well related to the disruption of sphingolipid metabolism in $LLC-PK_1$ cells.

• The Korean Society of Law and Medicine
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• v.11 no.2
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• pp.113-145
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• 2010

Nowadays, it is surely the quack which stands as one of the most controversial, problematic. the quack has been a consistent target of contested public protection strategies in the past few centuries in many countries. Recently, complementary and alternative medicine (CAM) is increasingly utilized and accepted by patients and providers throughout the health care system in the world, most accounts attribute this growing acceptability to the shortcomings of conventional medicine, the appeal of CAM's core beliefs, and the growing body of research indicating that CAM actually works. However, the governments of western countries have called for measures to ensure that the public are protected from incompetent and dangerous practitioners. Common to these controversies has been a suggestion to ban, exclude or limit the medical practice of those deemed to be damaging rather than improving the health of individuals as a measure of public protection. This article describes the experiences of western counties' health care system which is moving in a more pluralistic direction. By examining the ways in which regulatory efforts in the countries have come to address what is invariably described as a growing interest in CAM, this study show how the problem of CAM/quackery today is increasingly located in an ethical field of practitioner competency, qualifications, conduct, responsibility and personal professional development, regardless of the form of therapy in question. Many countries developed a series of measures and strategies to contain the acceptance of CAM groups, such as insisting on scientific evidence of safety and efficacy, resisting integration of CAM with conventional medicine and opposing government support for research and education. In a sense, those countries' movements serve to protect not only patients, but the dominant position of medicine and its allied professions, and to maintain existing jurisdictional boundaries within the healthcare system. The popular support for CAM will require that health professional stakeholders continue to address the challenges this poses, and at the same time protect their position at healthcare system. To cope with the quack, professional body, public sector and health authorities should consider the safety of consumers of healthcare and responding to the demands of the community for CAM therapies as well as the claims of the established healthcare professions. Finally, some implications for future health care were suggested.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1590-1598
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• 2008

Cell proliferation and differentiation are critical processes in a developing fetal rat brain, during which programmed cell death (PCD) also plays an important role. One of the decisive factors for PCD is Bcl-2 family proteins, where Bax induces cell death, whereas Bcl-2 acts as an inhibitor of PCD. As maternal drinking is known to cause fetal alcohol syndrome (FAS) or malformation of the fetal brain during pregnancy, the objective of the present study was to investigate whether maternal ethanol exposure alters the PCD-related Bax and Bcl-2 protein expression during fetal brain development. Pregnant female rats were orally treated with 10% ethanol and the subsequent expressions of the Bax and Bcl-2 proteins examined in the fetal brain, including the forebrain, midbrain, and hindbrain, from gestational day (GD) 15.5 to GD 19.5, using Western blots, in situ hybridization, and immunohistochemistry. With regard to the ratio of Bcl-2 to Bax proteins (Bcl-2/Bax), the Bax protein was dominant in the forebrain and midbrain of the control GD 15.5 fetuses, except for the hindbrain, when compared with the respective ethanol-treated groups. Moreover, Bcl-2 became dominant in the midbrain of the control GD 17.5 fetuses when compared with the ethanol-treated group, representing an alternation of the natural PCD process by ethanol. Furthermore, a differential expression of the Bcl-2 and Bax proteins was found in the differentiating and migrating zones of the cortex, hippocampus, thalamus, and cerebellum. Thus, when taken together, the present results suggest that ethanol affects PCD in the cell differentiation and migration zones of the prenatal rat brain by modulating Bax and Bcl-2 expression in an age- and area-dependent manner. Therefore, this is the first evidence that ethanol may alter FAS-associated embryonic brain development through the alteration of Bax and Bc1-2 expression.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.451-458
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• 2016

Since Modigliani and Miller developed their theory of capital structure in 1958, it has become one of the most debated issues in corporate management. This is because the capital structure decision necessarily affects financial risk and the firm's value. Throughout the research, one of the most concerning problems is determining what factors influence the firm's capital structure. Since Korean shipping firms have been suffering from a long term economic recession, an optimal capital structure has become increasingly critical to survive in the shipping industry. This paper studies panel data on 46 Korean shipping companies since 2000 to find the factors that affect capital structure. The results suggest that a negative relationship arises between firm size, tangible assets, profitability and non-debt tax shields against leverage. Otherwise, it proved that growth opportunity has a positive relationship with the firm's leverage. In the research model during a booming shipping economy, growth opportunity and non-debt tax shield are not associated with firm's capital structure.

• BMB Reports
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• v.45 no.2
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• pp.79-84
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• 2012

In asthma, T helper 2 (TH2)-type cytokines such as interleukin (IL)-4, IL-5, and IL-13 are produced by activated $CD^{4+}$ T cells. Dendritic cells played an important role in determining the fate of naive T cells into either $T_H1$ or $T_H2$ cells. We determined whether RG-II regulates the $T_H1/T_H2$ immune response by using an ovalbumin-induced murine model of asthma. RG-II reduced IL-4 production but increased interferon-gamma production, and inhibited GATA-3 gene expression. RG-II also inhibited asthmatic reactions including an increase in the number of eosinophils in bronchoalveolar lavage fluid, an increase in inflammatory cell infiltration in lung tissues, airway luminal narrowing, and airway hyperresponsiveness. This study provides evidence that RG-II plays a critical role in ameliorating the pathogenic process of asthmatic inflammation in mice. These findings provide new insights into the immunotherapeutic role of RG-II in terms of its effects in a murine model of asthma.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.593-604
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• 2011

This study examines potential growth and different perspectives on green-walls, which are being re-evaluated recently. The aim is to identify the viewer preferences concerning the walls by collecting a wide spectrum of information to create an interior design related comprehensive and intellectual database. Also based on this proposition, choosing a green surface of indoor wall as a specific example stimulus, identifying a relationship betweeationsviewer's preference factors. The relationship will formulate detailed and absolute qualities, which will reach potential areas that the green walls can be widely applied in. As a result of a factor analysis, the viewers classified into the 3 factors as is pleasant, gorgeous and rich about the stimulus. Preferred key factors, which are closely related to emotional image language, were; cool, tidy, comfortable and beautiful. The common factors in preferred design stimulus, in order of importance are color>elements>image/form/plants. Specific levels of design factors according to relevance are contrast>furniture> modern>central/creeper foliage plants. In the meantime, this study is leading the process of quantitative measurement of green-walls to a new design direction and it is critical to consistently experimenting to back up the theory with solid evidence.

• The Journal of Korean Medicine
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• v.29 no.2
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• pp.151-164
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• 2008

Objective: To investigate the effects of Yeongdamsagantang (YDGT) on apoptosis of neuronal cells that can result in dementia. Method: The water extract of the YDGT was tested in vitro for its beneficial effects on neuronal survival and neuroprotective functions, particularly in connection with $A{\beta}$ oligomer-related dementias. $A{\beta}$ oligomers derived from proteolytic processing of the ${\beta}-amyloid$ precursor protein (APP), including the $amyloid-{\beta}$ peptide $(A{\beta})$, play a critical role in the pathogenesis of Alzheimer's disease. A neuroblastoma cell line stably expressing an $A{\beta}$ oligomerassociated neuronal degeneration was used to investigate if YDGT inhibits formation of $A{\beta}$ oligomer. To measure the ATP generating level in mitochondrial membrane, luciferin/luciferase luminescence kit (Promega) and luminator was used, and to survey the protein's apparition, confocal microscopy was used. Result: $A{\beta}oligomer$ had a profound attenuation in the increase in CT105 expressing neuro2A cells from YDGT. Experimental evidence indicates that YDGT protected against neuronal damage from cells, but its cellular and molecular mechanisms remain unknown. We demonstrated that YDGT inhibited formation of $amyloid-{\beta}$ $(A{\beta})$ oligomers, which were the behavior, and possibly causative, features of AD. The decreased $A{\beta}$ oligomer in the presence of YDGT was observed in the conditioned medium of this $A{\beta}oligomer-secreting$ cell line under in vitro. In the cells, YDGT significantly attenuated mitochondrion-initiated apoptosis. Conclusion: (i) a direct $A{\beta}$ oligomer toxicity and the apoptosis initiated by the mitochondria; and (ii) multiple cellular and molecular neuroprotective mechanisms, including attenuation of apoptosis and direct inhibition of $A{\beta}$ oligomer aggregation, underlie the neuroprotective effects of YDGT.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.495-499
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• 2005

Purpose : Interleukin-4(IL-4) is a critical component of the Th2 cytokine pathway and contributes to severity of respiratory syncytial virus(RSV) bronchiolitis. Previous studies observed an association between severe RSV bronchiolitis in Korean children with a common haplotype of the IL4 promoter. This study was performed to investigate functional differences of the variant IL4 promoter haplotypes. Methods : Genomic DNA was obtained from 20 children from 6 to 48 months of age in the Department of Pediatrics, Seoul National University Bundang Hospital. The IL4 promoter spanning an 1.2 kb region was amplified and haplotype was determined by cloning and the PHASE reconstruction. Transcriptional activity of Jurkat T cells which were transfected with each IL4 haplotype were analyzed by use of luciferase assay. Results : Three haplotypes of the IL4 promoter have been identified with the frequency of GCC(7 percent), TCC(17 percent), and TTT(76 percent). The TTT haplotype demonstrated the highest luciferase values in both unstimulated and PMA-stimulated Jurkat T cells. Increases in transcriptional activity compared to GCC have been shown in TTT(5.3 fold higher) followed by TCC(4.2 fold higher) in unstimulated Jurkat T cells. Conclusion : We provided evidence that increased transcriptional activity of the TTT haplotype of the IL4 promoter, which has previously been over-represented in Korean children with severe RSV bronchiolitis. Therefore, IL-4 could play a potential role in the pathogenesis of RSV infection, possibly via an altered transcriptional activity of the different IL4 haplotypes.