• Title/Summary/Keyword: mediators

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Neuroprotective effects of paeoniflorin against neuronal oxidative stress and neuroinflammation induced by lipopolysaccharide in mice

  • Meng, Hwi Wen;Lee, Ah Young;Kim, Hyun Young;Cho, Eun Ju;Kim, Ji Hyun
    • Journal of Applied Biological Chemistry
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    • v.65 no.1
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    • pp.23-31
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    • 2022
  • Oxidative stress and neuroinflammation play important roles in the pathogenesis of Alzheimer's disease (AD). This study investigated the protective effects of paeoniflorin (PF) against neuronal oxidative stress and neuroinflammation in lipopolysaccharide (LPS)-induced mice. The brains of LPS-injected control group showed significantly increased neuroinflammation by activating the nuclear factor kappa B (NF-κB) pathway and increasing inflammatory mediators. However, administration of PF significantly attenuated oxidative stress by inhibiting lipid peroxidation, nitric oxide levels, and reactive oxygen species production in the brain; PF at doses of 5 and 10 mg/kg/day downregulated the expression of NF-κB pathway-related proteins and significantly decreased inflammatory mediators including inducible nitric oxide synthase and cyclooxygenase-2. Moreover, the levels of brain-derived neurotrophic factor and its receptor, tropomycin receptor kinase B, were significantly increased in PF-treated mice. Furthermore, acetylcholinesterase activity and the ration of B-cell lymphoma 2 (Bcl-2)/Bcl-2 associated X were significantly reduced by PF in the brains of LPS-induced mice, resulting in the inhibition of cholinergic dysfunction and neuronal apoptosis. Thus, we can conclude that administration of PF to mice prevents the development of LPS-induced AD pathology through the inhibition of neuronal oxidative stress and neuroinflammation, suggesting that PF has a therapeutic potential for AD.

Effects of Household Chaos on Preschoolers' Aggression and Prosocial Behavior: Sleep Problems and Executive Function as Mediators (가정 내 혼란이 유아의 공격성과 친사회적 행동에 미치는 영향: 수면문제와 실행기능의 매개효과)

  • Bomi Lee;Jeeun Noh;Nana Shin
    • Human Ecology Research
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    • v.61 no.1
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    • pp.1-13
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    • 2023
  • Household chaos, represented by high levels of disorganization and instability in the home, has been linked with suboptimal outcomes for preschoolers. The aim of this study was to examine the roles that sleep problems and executive function play in the association between household chaos and preschoolers' aggression and prosocial behavior. The sample for the study consisted of 420 preschoolers and their mothers. The mothers provided reports on the level of chaos in the home and their preschoolers' sleep problems, executive function, and social behavior, including aggression and prosocial behavior. The data was analyzed using structural equation modeling. When preschoolers' sleep problems and executive function were included in the model as mediators, the results indicated that household chaos did not have direct effects on preschoolers' aggression and prosocial behavior. Such effects were instead serially mediated by preschoolers' sleep problems and executive function, respectively. The higher the degree of household chaos, the more preschoolers displayed sleep problems and deficits in executive function, resulting in more aggression and less prosocial behavior. The findings from this study emphasize the significance of reducing household chaos in order to reduce preschoolers' aggression and promote prosocial behavior. They also underscore the need to identify additional variables that mediate the impact of household chaos on preschoolers' social outcomes.

Immunostimulatory Activity of Syneilesis palmata Leaves through Macrophage Activation and Macrophage Autophagy

  • Jeong Won Choi;Hyeok Jin Choi;Gwang Hyeon Ryu;Seung Woo Im;Jae Won Lee;Jin Boo Jeong
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2023.04a
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    • pp.44-44
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    • 2023
  • Syneilesis palmata (SP) has been used as a traditional medicinal plant and vegetable. SP was reported to exert pharmacological activities such as anti-inflammation, anti-cancer, and anti-HIV. However, there are no studies on the immunostimulatory activity of SP. Thus, in this study, we report that S. palmata leaves (SPL) induce the activation of macrophages. An increase in both secretions of immunostimulatory mediators and phagocytotic activity was observed in SPL-treated RAW264.7 cells. However, this was reversed by inhibition of TLR2/4. In addition, the p38 inhibition reduced the SPL-mediated secretion of immunostimulatory mediators, and the SPL-mediated p38 activation was blocked by the TLR2/4 inhibition. SPL augmented both p62/SQSTM1 and LC3-II. TLR2/4 inhibition blocked the SPL-mediated increase of p62/SQSTM1 and LC3-II. These findings indicate that SPL may activate macrophages through TLR2/4-dependent p38 activation and activate autophagy through TLR2/4 stimulation.

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Nypa fruticans Wurmb Exerts Anti-Inflammatory Effects through NF-kB and MAPK Signaling Pathway

  • Hye-Jeong Park;So-Yeon Han;Jeong-Yong Park;Seo-Hyun Yun;Mi-Ji Noh;Soo-Yeon Kim;Tae-Won Jang;Jae-Ho Park
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2021.04a
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    • pp.56-56
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    • 2021
  • Nypa fruticans Wurmb is a mangrove plant belonging to Araceae family. N. fruticans is typically found in Southeast Asia, and in some parts of Queensland, Australia. N. fruticans has phytochemicals, phenolics, and flavonoids. In this study, we investigated the anti-inflammatory effects of the ethyl acetate fraction of N. fruticans (ENF) on the production and expression of cytokines and inflammatory mediators through the major signal transduction pathways. ENF attenuated the level of cytokines in a dose-dependent manner and decreased the production of nitric oxide (NO). ENF decreased the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) via alleviating transcription of nuclear factor-kappa B (NF-κB) by an inhibitor of nuclear factor-kappa B (IκB) degradation. Furthermore, mitogen-activated protein kinase (MAPK) signaling pathways (ERK1/2, JNK1/2, and p38) are known to be involved in the inflammatory response. Phosphorylations of ERK1/2, JNK1/2, and p38 were significantly decreased compared with the ENF-untreated control. Conclusively, ENF was related to alleviating various pro-inflammatory mediators through IκB/NF-κB and MAPK signaling pathways, including p65 translocation to the nucleus.

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Effect of nutrient intake and dietary diversity score on osteoporosis of middle-aged adults and elderly based on 2015-2017 Korean National Health and Nutrition Examination Survey data (2015-2017년 국민건강영양조사 자료를 활용하여 영양소 섭취와 식이다양성이 중년 이후 성인과 노인의 골다공증에 미치는 영향)

  • Kwon, Sehyug;Lee, Jung Sug
    • Journal of Nutrition and Health
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    • v.53 no.2
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    • pp.155-174
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    • 2020
  • Purpose: The purpose of this study was to investigate the effects of nutrient intake and dietary diversity score (DDS) on osteoporosis after controlling for sex, age, socioeconomic level, drinking, smoking, physical activity, and body mass index (BMI) as mediators using the 2015-2017 Korean National Health and Nutrition Examination Survey (KNHANES) data. Methods: This study was focused on the age group of 50s and older by using the 2015-2017 KNHANES data. Subjects diagnosed with osteoporosis were classified as the osteoporosis group, and the other subjects were classified as the normal group. Logistic regression was used to assess the association between nutrient intake and DDS after controlling for mediators. Results: The risk of osteoporosis was 2.38 times lower in the 50-65 age group than in the 75 years and older group. The mediators affecting the incidence of osteoporosis by age group were sex, age, household income level, and education level in the 50-64 age group; sex, education level, drinking, and BMI in the 65-74 age group; and sex, age, current smoking, drinking, BMI, and energy intake in the 75 years and older group. The effect of nutrient intake on osteoporosis, with the exception of vitamin B1, was fully mediated by these mediators. The effect of vitamin B1 was partially mediated by mediators in the age group of 65-74 years, and vitamin B1 was effective for preventing the risk of osteoporosis by 25% when consumed over EAR. The effect of DDS was partially mediated in the age group of 75 years and older, and DDS of 2 or less increased the risk of osteoporosis by 2.59 times. Conclusion: As a result of this study, it is necessary to recommend the balanced intake of various foods including grains, meat·fish·legumes, vegetables, fruits, and dairy products as dietary guidelines for the prevention of osteoporosis and promotion of bone health in the elderly.

When Robots Meet the Elderly: The Contexts of Interaction and the Role of Mediators (노인과 로봇은 어떻게 만나는가: 상호작용의 조건과 매개자의 역할)

  • Shin, Heesun;Jeon, Chihyung
    • Journal of Science and Technology Studies
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    • v.18 no.2
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    • pp.135-179
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    • 2018
  • How do robots interact with the elderly? In this paper, we analyze the contexts of interaction between robots and the elderly and the role of mediators in initiating, facilitating, and maintaining the interaction. We do not attempt to evaluate the robot's performance or measure the impact of robots on the elderly. Instead, we focus on the circumstances and contexts within which a robot is situated as it interacts with the elderly. Our premise is that the success of human-robot interaction does not depend solely on the robot's technical capability, but also on the pre-arranged settings and local contingencies at the site of interaction. We select three television shows that feature robots for the elderly and one "dementia-prevention" robot in a regional healthcare center as our sites for observing robot-elderly interaction: "Grandma's Robot"(tvN), "Co-existence Experiment''(JTBC), "Future Diary"(MBC), and the Silbot class in Suwon. By analyzing verbal and non-verbal interactions between the elderly and the robots in these programs, we point out that in most cases the robots and the elderly do not meet one-to-one; the interaction is usually mediated by an actor who is not an old person. These mediators are not temporary or secondary components in the robot-elderly interaction; they play a key role in the relationship by arranging the first meeting, triggering initial interactions, and carefully observing unfolding interactions. At critical moments, the mediators prevent the interaction from falling apart by intervening verbally or physically. Based on our observation of the robot-elderly interaction, we argue that we can better understand and evaluate the human-robot interaction in general by paying attention to the existence and role of the mediators. We suggest that researchers in human-robot interaction should expand their analytical focus from one-to-one interactions between humans and robots to human-robot-human interactions in diverse real-world situations.

Effects of Anti-Asthma Agents on Cytokine and Prostaglandin Production in Ovalbumin-Sensitized Splenocytes

  • Won, Tae-Joon;Lee, Chan-Woo;Kwon, Seok-Joong;Lee, Do-Ik;Park, So-Young;Hwang, Kwang-Woo
    • Biomolecules & Therapeutics
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    • v.17 no.4
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    • pp.388-394
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    • 2009
  • The cytokines which is produced by allergen-specific T helper (Th) cells play a pivotal role in the pathogenesis of asthma. Asthma is caused by exaggerated T-helper 2 (Th2)-based immune responses. It is suggested that controlling such Th2-based response is necessary for asthma therapy. The current therapies for asthma focus primarily on control of symptoms and suppression of inflammation, without affecting the underlying cause. So, we examined that anti-asthmatic drugs might have play a certain role in Th2/Th1 balance. Splenocytes isolated from ovalbumin (OVA)-sensitized mice cultured with anti-asthmatic drugs. It is well known that Th2 and Th1 immune responses can balance one another, as Th2 mediators suppress Th1 responses and Th1 mediators similarly inhibit Th2 responses. But salmeterol inhibits both of Th1 and Th2 mediators, which salmeterol is a suppressor of immune responses not only a suppressor of Th2-based immune responses. Aminophylline is a weak suppressor of immune responses. But ipratropium and cromoglycate don't have any suppressor effect to Th2-driven responses. They only have suppressor effect to Th1 immune responses. Salmeterol, ipratropium, aminophylline, and cromoglycate augmented mRNA levels of CRTH2, EP2, and IP2 receptors in OVA-sensitized splenocytes. It is well known that the up-regulation of CRTH2 - $PGD_2$ receptor - results in restraint of eosinophil recruitment and that the increment of IP and EP2 - $PGI_2$ and $PGE_2$ receptor, respectively - may induce the accumulation of cAMP that decrease the effector function of T cells. Moreover salmeterol and cromoglycate increase the mRNA expression of $PGD_2$ synthase. These findings indicate that anti-asthma agents may alleviate the immunological responses that cause the asthmatic diseases.

The Effects of Dynamic Capabilities on Enterprise Performance: Focusing on the Mediating Effect of Ambidextrous Innovation Activities (동적역량이 기업성과에 미치는 영향: 양면적혁신활동의 매개효과 중심으로)

  • Choi, In Woo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.4
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    • pp.175-192
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    • 2020
  • This study analyzed the effects of corporate dynamic capabilities on enterprise performance by using ambidextrous innovation activities as mediators, focusing on SME employees. The sub-variables of dynamic capabilities were divided into opportunity exploration capability, resource acquisition capability, and resource reconstruction capability. 282 questionnaires collected from small and medium-sized enterprises residing in the metropolitan area were used for empirical analysis. SPSS v22.0 and Process macro v3.4 were used to analyze the parallel multiple mediation model. First, the results of the analysis showed that opportunity exploration capability, resource acquisition capability had a positive (+) effect on the ambidextrous innovation activities, and the effect of resource reconstruction capability on ambidextrous innovation activities was not significant. Second, the ambidextrous innovation activities had a significant effect on the enterprise performance. Third, it was found that opportunity exploration capability and resource acquisition capability had a positive (+) effect on enterprise performance, and the effect of resource reconstruction capability on enterprise performance was not significant. Fourth, the ambidextrous innovation activity mediated the relationship between opportunity exploration capability and enterprise performance. Fifth, the ambidextrous innovation activity mediated the relationship between resource acquisition capability and enterprise performance. Sixth, the ambidextrous innovation activity did not mediate the resource reconstruction capability and the enterprise performance. As a follow-up study, it is necessary to find third mediators besides the mediators used in this study, analyze the serial mediation model through these, and study for the moderated mediation analysis through the conditional process model in which the moderator is introduced.

Effects of plant-based Korean food extracts on lipopolysaccharide-stimulated production of inflammatory mediators in vitro

  • Lee, Sun Young;Kim, Yoo-Sun;Lim, Ji Ye;Chang, Namsoo;Kang, Myung-Hee;Oh, Se-Young;Lee, He-Jin;Kim, Hyesook;Kim, Yuri
    • Nutrition Research and Practice
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    • v.8 no.3
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    • pp.249-256
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    • 2014
  • BACKGROUND/OBJECTIVES: The traditional Korean diet is plant-based and rich in antioxidants. Previous studies have investigated the potential health benefits of individual nutrients of Korean foods. However, the cumulative effects of a Korean diet on inflammation remain poorly understood. Therefore, the aim of this study was to investigate the anti-inflammatory effects of a plant-based Korean diet. MATERIALS/METHODS: Using data from the Fifth Korean National Health and Nutrition Examination Survey, 75 individual plant food items were selected which represent over 1% of the total diet intake of the Korean diet. These items were classified into ten different food groups, and the vegetable (Veg) and fruit (Fruit) groups were studied based on their high antioxidant capacity. For comparison, a mixture of all ten groups (Mix) was prepared. To produce a model of inflammation with which to test these Veg, Fruit, and Mix plant-based Korean food extracts (PKE), RAW264.7 macrophages were treated with lipopolysaccharide (LPS). RESULTS: Levels of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$), as well as protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were found to be lower following PKE treatment. Furthermore, PKE treatment was found to suppress tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) via the nuclear transcription factor kappa-B ($NF-{\kappa}B$) signaling pathway. Overall, the Mix group exhibited the greatest anti-inflammatory effects compared with Veg and Fruit PKE group. CONCLUSIONS: Inhibition of LPS-induced pro-inflammatory mediators by the PKE tested was found to involve an inhibition of NF-kB activation. Moreover, PKE tested have the potential to ameliorate various inflammation-related diseases by limiting the excessive production of pro-inflammatory mediators.

Study on the Integrated SCM Performance Formation Model through Supplier Development Project and Asset Specificity (공급자개발계획과 자산전용성을 통한 통합적 SCM성과형성모델에 관한 연구)

  • Song, Jang-Gwen;Oh, Se-Gu
    • Journal of Distribution Science
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    • v.12 no.10
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    • pp.85-97
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    • 2014
  • Purpose - This study aims to clarify through which process asset specificity and supplier development project (SDP) affect performance. Cooperation, partnership, the level of information exchange, and the importance of information sharing are considered significant variables as mediators related to the process. Finally, the performance formation model of the supply chain through asset specificity and supplier development project would be suggested as being a result of this study. Research design, data, and methodology - Data collection was as follows: questionnaires were distributed to 250 companies that have business ties with H Company. The empirical study to test our hypothesis was based on statistical analysis (using SPSS 19.0 and AMOS 19.0). The hypothesis of this paper is that the asset specificity and supplier development project variables have positive effects on the following variables: mediators such as cooperation and partnership (reliability and dependence); and the cooperation and partnership variables have a positive effect on the following variables: level of information sharing, the importance of information sharing, and level of information sharing; the importance of information sharing has a positive effect on supply chain performance. We tested our hypothesized model utilizing path analysis with latent variables. Results - First, it was found that asset specificity has significant positive effects on cooperation (H1), reliability (H2), and dependability (H3). Second, it was proved that the level of comprehension on the purpose of SDP has positive effects significantly on cooperation (H4), reliability (H5), and dependability (H6). Third, the hypotheses related to cooperation were all significantly accepted. The relationships of cooperation with the level (H7) and importance (H8) of information sharing were significant. Fourth, the hypotheses related to reliability were all significantly accepted. The relationships of reliability with the level (H9) and importance (H10) of information sharing were significant. In terms of dependability, however, the hypotheses were partially accepted. The effect of dependability was significant on the importance of information sharing (H12), but insignificant on the level of information sharing (H11). Finally, the causal relationships from the level of information sharing to SCM performance (H13) and from the importance of information sharing to SCM performance (H14) were both significantly accepted. Conclusion - First, with rapid changes in the business environment, enterprises should acquire the right information to properly implement SCM. For successful SCM, firms should understand the supplier development project. Second, asset specificity and the level of comprehension on SDP have significant effects both on cooperation and partnership (reliability and dependability). Third, mediators such as cooperation, reliability, and dependability significantly affect the level and importance of information sharing. Fourth, the level and importance of information sharing have significant impacts on SCM performance. This paper makes a meaningful contribution to further the understanding of how SDP affects SCM performance. Finally, successful SCM performance is achieved by information sharing through a collaborative environment and partnership (confidence & dependence) rather than by investing only in setting up an information system.