• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.597-603
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• 2008

Purpose : Obesity is associated with insulin resistance. Insulin resistance and the presence of pro-inflammatory mediators are thought to cause a state of vascular endothelial dysfunction, an abnormal lipid profile, hypertension, and vascular inflammation. These chronic inflammatory responses, which are characterized by abnormal cytokine production, lead to activation of a pro-inflammatory signaling pathway. Leptin is an important mediator of inflammatory processes and immune-mediated diseases. The purpose of this study was to investigate the relationship between leptin and various cytokines associated with obesity in adolescents. Methods : Sixty-six obese adolescents (between 16-17 years of age, obesity index >130%) and 26 normal controls were included in this study. Obesity index and body mass index (BMI) were calculated. Serum lipid profile, AST and ALT were tested after 10 hours of fasting. Tumor necrosis factor alpha (TNF-${\alpha}$) and Interleukin-6 (IL-6) levels were measured by ELISA. Insulin, adiponectin, and leptin levels were estimated by radioimmunoassay. Results : Leptin was significantly higher in the obese adolescents compared to the control adolescents ($12.0{\pm}6.8ng/mL$ vs $6.3{\pm}1.0ng/mL$). TNF-${\alpha}$, IL-6, and insulin were significantly higher in the obese adolescents. Adiponectin was significantly lower in the obese group than the control group ($3.3{\pm}1.9{\mu}g/mL$ vs $5.0{\pm}1.4{\mu}g/mL$). Leptin had positive correlations with obesity index, BMI, and IL-6. Conclusion : In obese adolescents, leptin, TNF-${\alpha}$, IL-6, and insulin might be important mediators of obesity. Further clinical research is necessary to ascertain leptin as a predictor of cardiovascular diseases and to develop a guideline for clinical intervention.

• Proceedings of the Korean Nutrition Society Conference
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• 1995.11b
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• pp.11-34
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• 1995

Growth hormone (GH) plays a key role in regulating postnatal growth and can stimulate growth of animals by acting directly on specific receptors on the plasma membrane of tissues or indirectly through stimulating insulin-like growth factor (IGF)-I synthesis and secretion by the liver and other tissues. IGF-I and IGF-Ⅱ are polypeptides with structural similarity with proinsulin that stimulate cell proliferation by endocrine, paracrine and autocrine mechanisms. The initial event in the metabolic action of IGFs on target cells appears to be their binding to specific receptors on the plasma membrane. Current evidence indicates that the mitogenic actions of both IGFs are mediated primarily by binding to the type I IGF receptors, and that IGF action is also mediated by interactions with IGF-binding proteins (IGFBPs). Six distinct IGFBPs have been identified that are characterized by cell-specific interaction, transcriptional and post-translational regulation by many different effectors, and the ability to either potentiate or inhibit IGF actions. Nutritional deficiencies can have their devastating consequence during growth. Although IGF-I is the major mediator of GH's action on somatic growth, nutritional status of an organism is a critical regulator of IGF-I and IGFBPs. Various nutrient deficiencies result in decreased serum IGF-I levels and altered IGFBP levels, but the blood levels of GH are generally unchanged or elevated in malnutrition. Effects of protein, energy, vitamin C and D, and zinc on serum IGF and IGFBP levels and tissue mRNA levels were reviewed in the text. Multiple factors are involved in the regulation of intestinal epithelial cell growth and differentiation. Among these factors the nutritional status of individuals is the most important. The intestinal epithelium is an important site for mitogenic action of the IGFs in vivo, with exogenous IGF-I stimulating mucosal hyperplasia. Therefore, the IGF system appears to provide and important mechanism linking nutrition and the proliferation of intestinal epithelial cells. In order to study the detailed mechanisms by which intestinal mucosa is regulated, we have utilized IEC-6 cells, an intestinal epithelial cell line and Caco-2 cells, a human colon adenocarcinoma cell line. Like intestinal crypt cells analyzed in vivo or freshly isolated intestinal epithelial cells, IEC-6 cells and Caco-2 cells possess abundant quatities of both type Ⅰ and type Ⅱ IGF receptors. Exogenous IGFs stimulate, whereas addition of IGFBP-2 inhibits IEC-6 cell proliferation. To investigate whether endogenously secreted IGFBP-2 inhibit proliferation, IEC-6 cells were transfected with a full-length rat IGFBP-2 cDNA anti-sense expression construct. IEC-6 cells transfected with anti-sense IGFBP-2 protein in medium. These cells grew at a rate faster than the control cells indicating that endogenous IGFBP-2 inhibits proliferation of IEC-6 cells, probably by sequestering IGFs. IEC-6 cells express many characteristics of enterocyte, but do not undergo differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation after reaching confluency. We have demonstrated that Caco-2 cells produce IGF-Ⅱ, IGFBP-2, IGFBP-3, and an as yet unidentified 31,000 Mr IGFBP, and that both mRNA and peptide secretion of IGFBP-2 and IGFBP-3 increased, but IGFBP-4 mRNA and protein secretion decreased after the cells reached confluency. These changes occurred in parallel to and were coincident with differentiation of the cells, as measured by expression of sucrase-isomaltase. In addition, Caco-2 cell clones forced to overexpress IGFBP-4 by transfection with a rat IGFBP-4 cDNA construct exhibited a significantly slower growth rate under serum-free conditions and had increased expression of sucrase-isomaltase compared with vector control cells. These results indicate that IGFBP-4 inhibits proliferation and stimulates differentiation of Caco-2 cells, probably by inhibiting the mitogenic actions of IGFs.

• Journal of Korea Technology Innovation Society
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• v.20 no.1
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• pp.1-33
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• 2017

In the last decades, technology-oriented small firms, i.e. venture businesses, have been increasingly engaged in R&D collaborations with external parties as strategic means for technological innovation. Despite ample evidence on the benefit of such collaborations for the firms, there has been less attention to examining whether and how the firms' social interactions with cooperating partners and their managerial characteristics contribute to that benefit. Drawing on the theories of social capital and entrepreneurial orientation, this study is to remedy this gap. The theory of social capital, referring to a sum of the value and potential resources embedded in social relationships of collectives, provides an integrated view of social factors among cooperating partners, e.g. strong ties, network stability, trust, reciprocity, shared vision and value. It categorizes these factors into structural, relational, and cognitive dimensions of social capital. Entrepreneurial orientation theory captures firms' managerial characteristics as a combination of innovativeness, proactiveness, and risk-taking. This addresses firms' managerial process to utilize and combine internal and external resources for wealth creation and opportunity realization. Against this background, this study investigates what roles social capital among cooperating R&D partners and entrepreneurial orientation of the collaborating firms play for collective performance improvement in R&D collaborations. In terms of the collective performance, this study adopts two indicators: technological competitiveness and business performance. Technological competitiveness refers to the contribution of a technology developed by a cooperative R&D project to competitive advantage of a firm while business performance is defined as the financial and economic outcome of a collaboration. Using a sample of 218 Korean ventures engaging in R&D collaboration with external parties, the author finds the significant effects of social capital (i.e. structural, relational, and cognitive dimensions) and entrepreneurial orientation (i.e. innovativeness, proactiveness, and risk-taking) on both of the technological competitiveness and the business performance. Further, the higher the social capital among R&D partners, the more likely it is to foster the entrepreneurial orientation at firm-level. Most importantly, the entrepreneurial orientation at firm-level is an significant mediator of the relationship between social capital and collective performance. Beyond these novel empirical findings, this study contributes to the literature on R&D collaboration. The findings' implications for management and policy are deeply discussed in the conclusion.

• The Journal of Industrial Distribution & Business
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• v.8 no.6
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• pp.51-60
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• 2017

Purpose - This study aimed to investigate the correlation between the social activity of the elderly and recognition of family cohesion of the elderly who are exposed to the current aging society. In addition, the study has delved into the method of family cohesion improvement through the differences between groups based on the mediator effect of how the results have effects on the elderly's self-control capabilities. Research design, data, and methodology - This study has targeted the elderly who are attending the elderly university among users in seven community centers located in Seoul and Gyeonggi-do area. The study has also conducted a survey by the format of a half-structured questionnaire. It is aiming to investigate the elderly's family cohesion with children and their self-control capability, and understand their satisfaction of social activity to help successful elderly life. The study has suggested the following as mentioned. First, the study analyzed that the perceptual factor of family cohesion with children would be deducted based on advanced researches. Second, the influencing relationship would be analyzed through the relational analysis between the elderly's family cohesion and social activity. Results - The family cohesion with children has a significant effect on psychological happiness and it showed the influencing relationship with improvement of the elderly's self-control capability. Therefore, creating fellowship through meaningful conversation with children would be needed. In addition, various programs and consultant service would be offered to build healthy relationship between aged parents and their children. Through this, the elderly will be able to have not only better relationships with their family, but also increased psychological health and well-being as well. Conclusions - It is needed that not only supporting policies for children who take care of aged parents but also that the elderly who need long-term care could meet their children whenever they want through increased numbers of sanatoriums operated by cities and countries. In addition, the nation would offer financial and administrative support continuously so that people receive the benefits from sanatoriums located in the locality of children's residence beyond the elderly's residence. Moreover, social infra would be established as well.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.611-626
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• 1998

Cytokines are intercellular peptide mediators that regulate homeostasis and host defense reactions in living body. Of the diversity of cytokines in terms of biological accomplishment, interleukin $1-{\beta}$($IL-1{\beta}$) and tumor necrosis factor(TNF) are the most conspicuous cytokines with a wide variety of effects on cells involved in inflammatory and immune responses, and likely to be involved in the inflammatory pathogenesis of oral tissue as well. The present study was designed to explicate the role of $IL-1{\beta}$ on inflammatory revelation of oral tissues in mice biochemically. In the Induced arthritis by injection of 10${\mu}g$ LPS shown the relaese of 0.93 ${\mu}g$ $IL-1{\beta}$/joint with a peak at at 4-5 h. and diminished at 24t and the release of $TNF_{\alpha}$ of 1.25 ${\mu}g$/joint with a peak at 2-3h and diminished at 6h. After injection of th $IL-1{\beta}$ into the joint, the mumber of leucocytes proliferated with a peak at 4-5h and diminished at 36h and the loss of proteoglycan showed with maximum at 15-30h. After injection of $IL-1{\beta}$ into the oral tissue, cycloosygenase metabolites ($PGE_2$) accumulated in the oral tissue with dose dependant. These elucidated $IL-1{\beta}$ to be inflammatory mediator in the early phase of its pathogenesis. Intraoral injection of recombinant $IL-1{\beta}$ induced the proliferation of leukocytes in situ. $IL-1{\beta}$ took an pertinent part in the development of inflammation and the succession of cellular infiltration. The results exemplify that $IL-1{\beta}$ plays a significant role in mediating inflammatory response induced by LPS in oral tissue, the inflammatory response is regulated by $IL-1{\beta}$ at an acute phase of pathogenesis.

• Tuberculosis and Respiratory Diseases
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• v.39 no.3
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• pp.228-235
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• 1992

Background: Although polymorphonuclear leukocytes (PMN) are important in protecting the airways and alveolar surfaces, there is evidence that they can also injure the lung while exercising their defensive role. However it has been unclear whether PMN-induced pneumocyte injury is mediated by their direct cytotoxic effect on target cells or by PMN-derived cytotoxic mediators. On the other hand histamine was known not only to act as an important chemical mediator participated in the pathogenesis of some atotic and allegic disorders, but also to have an inhibitory effect on normal PMN functions. Method: To study the mechanism by which PMN induce pneumocyte injury, we cocultured PMN from four healthy nonsmokers or their PMN-derived supernatants (PMN-SPN) with monolayers of $^{51}Cr$-labeled human A549 pneumocytes and compared PMN-and PMN-SPN-mediated pneumocyte injuries measured by $^{51}Cr$ release assay. We also compared the effects of histamine on each pneumocyte injury. Results: 1) PMN-SPN showed more injurious effect on A549 pneumocytes than that of PMN itself regardless histamine pretreatment of PMN. 2) Pneumocyte injury by PMN with histamine pretreatment was increased or decreased compared with that by PMN without histamine pretreatment, according to histamine concentrations, and PMN stimulating agents and their concentrations. 3) Pneumocyte injury by PMN-SPN with histamine pretreatment tended to be decreased compared with that by PMN-SPN without histamine pretreatment. Conclusion: Our results suggest that PMN-SPN may play more important role in mediating pneumocyte injury than PMN itself and that histamine may partially play a protective role on PMN-induced pneumocyte injury. Alternatively we conclude that the effects of histamine on PMN-induced pneumocyte injury may be affected by microenvironment in vivo.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.161-171
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• 1999

Background: Interleukin-12 (IL-12) can induce antitumor effects in vivo. This antitumor effect is associated with T cell infiltration but the effect of IL-12 on the steps of T cell migration into the tumor tissue has not been fully elucidated. This study focused on the effect of IL-12 on the tumor growth and the metastasis and on the expression of E-selectin, an adhesion molecule which is activated endothelial specific in its expression. In addition, we studied whether the expression of E-selectin is associated with the TNF-$\alpha$, a cytokine that its production is increased by IL-12 and has functions inducing a variety of adhesion molecules. Methods: Mice of C57BL/6 strain were injected with Lewis lung cancer cells followed by either IL-12, TNF-$\alpha$, or normal saline by intraperitoneal route. Twenty eight days after tumor cell inoculation, metastatic nodules of lung were enumerated and immunohistochemical staining of the subcutaneous tumors were performed with monoclonal antibodies to CD4, CD8, CD16, and E-selectin. In IL-12 treated mice, the subcutaneously implanted Lewis lung tumors were decreased in size and the metastases were also decreased in number compared to control mice. On tumor tissues, increased infiltration of CD4+, CD8+, and CD16+ cells were oberved in IL-12 treated mice compared to control mice. In control mice, E-selectin was absent on tumor vessels, but the expression of E-selectin was increased on tumor vessels of IL-12 treated mice. Administration of TNF-$\alpha$ increased not only the expression of E-selectin but also infiltrations of CD4+, CD8+, and CD16+ cells on tumor tissues. Conclusions: These results demonstrate that IL-12 inhibits tumor growth and metastases through infiltrations of inflammatory cells in mouse model of Lewis lung carcinoma and E-selectin may playa role in inflammatory cell recruitment on tumor tissue following IL-12 administration. Also, TNF-$\alpha$ may have a role as a mediator responsible for the IL-12 induced expression of E-selectin.

• Tuberculosis and Respiratory Diseases
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• v.52 no.3
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• pp.219-229
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• 2002

Background : Sepsis-induced acute lung injury (ALI) is caused by many cellular and humoral mediators induced by an endotoxin. Histamine, which is widely distributed in the lungs and has been considered as an important mediator of sepsis. It increases P-selectin expression on the endothelial cell surfaces and induces IL-8 secretion. Therefore, an endotoxin-induced histamine may be related to neutrophil-mediated ALI by inducing the migration and activation of neutrophils in the lung tissue. However, the role of endogenous histamine in endotoxin ALI has not been clarified. The purpose of this study was to investigate how endotoxin-induced ALI is influenced by endogenous histamine and to identify the possible mechanism of action. Materials and Methods : The study consisted of 4 groups using Sprague-Dawley rats : 1) control group, where the rats were infused intratracheally by normal saline, 2) an endotoxin group, where lipopolysaccharide (LPS) was administered intratracheally 3) the $H_2$ receptor antagonist-treated group ($H_2$ group) and 4) the $H_1$ receptor antagonist-treated group ($H_1$ group), where $H_2$-receptor blocker (ranitidine) and $H_1$-receptor blocker(pyrilamine) were co-treated intravenously with the intratracheal administration of an endotoxin. The lung leak index using $I^{125}$-BSA, the total protein and LDH concentration in the lung lavage fluid, myeloperoxidase(MPO) activity in the lung tissue, the pathologic score and the total number of neutrophils, TNF-$\alpha$, IL-$1{\beta}$ and IL-10 in lung lavage (BAL) fluid were measured in each group as the indices of lung injury. Results : Compared to the control group, the endotoxin group exhibited significant increases in all lung injury indices. Significant reductions in the endotoxin-mediated increases in lung leak index (p<0.05) were observed in both the $H_1$ and $H_2$ groups. In addition the total protein (p<0.05) and LDH concentration (p<0.05) in the BAL fluid were also lower in the $H_2$ group compared to the endotoxin group. However, there was no change in the MPO activity in the lung tissue, the pathologic score and the total number of neutrophils in the BAL fluid in both the $H_2$ and $H_1$ groups compared to the endotoxin group. The increases in TNF-$\alpha$ IL-$1{\beta}$ and IL-10 concentrations in the BAL fluid observed in the endotoxin group were not reduced in the $H_2$ and $H_1$ groups. Conclusion : Antihistamine attenuated the enhanced alveolar-capillary permeability induced by the endotoxin via the $H_2$ receptor. However the attenuating mechanism may not be related to the pathogenesis of neutrophil dependent lung injury.

• Tuberculosis and Respiratory Diseases
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• v.67 no.1
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• pp.14-20
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• 2009

Background: The pathophysiologic mechanisms of radiation-induced lung injury should be elucidated to enhance the therapeutic efficacy of radiotherapy and to manage patients exposed to serious radiation by accident. It has been suggested that pro-inflammatory cytokines play an important role in radiation-induced effect on the lung. This study was aimed to investigate changes in pro-inflammatory cytokines such as TNF-$\alpha$, MIP-2, IL-1$\beta$ and HMGB1, a newly recognized inflammatory mediator. Methods: The chests of BALB/c mice were selectively irradiated with single fraction of 20 Gy and then sacrificed at indicated times. Pathologic changes in the lung were examined after H&E staining. The expression level of pro-inflammatory cytokines was evaluated by ELISA kits in lung homogenate and in serum. Results: Radiation induced inflammatory changes and mild fibrosis in lung. Biphasic increase of TNF-$\alpha$ and IL-1$\beta$ was found in lung homogenate at 4 hours and at 3 weeks after radiation. The elevation in the second phase tended to be more intense. However, there was no similar change in serum. MIP-2 level was slightly increased in lung homogenate at 4 hours, but not at 3 weeks. HMGB1 was increased at 3 weeks in serum while there was no significant change in lung homogenate. Conclusion: Radiation induced a biphasic increase in TNF-$\alpha$ and IL-1$\beta$. The effective control of second phase cytokine elevation should contribute to preventing severe lung fibrosis caused by radiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1552-1559
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• 2013

Rubus coreanus Miquel (RCM) has been used as one of the Korean traditional medicines for prostate health. In addition, recent studies have reported that RCM reduced chronic inflammatory diseases such as cancer, and rheumatoid arthritis. Therefore, in this study, we investigated the effects of unripe and ripe RCM on inflammationrelated gene expressions in LPS-stimulated mouse peritoneal macrophages. Mice were fed with 2% unripe RCM (U2), 10% unripe RCM (U10), 2% ripe RCM (R2), and 10% ripe RCM (R10) for 8 weeks. Peritoneal macrophages were isolated and stimulated with LPS then proinflammatory mediators (TNF-${\alpha}$, IL-$1{\beta}$, and IL-6), and prostaglandin E2 ($PGE_2$) productions were assessed. Moreover, gene expression profiles were analyzed by cDNA microarray method. Unripe and ripe RCM significantly reduced TNF-${\alpha}$ production but only unripe RCM decreased IL-$1{\beta}$ and IL-6 production. RCM intake significantly reduced inflammatory-related gene expressions such as arachidonate 5-lipoxygenase, interleukin 11, and nitric oxide synthase 2. Furthermore, unripe and ripe RCM significantly decreased ceruloplasmin, tissue plasminogen activator, thrombospondin 1, and vascular endothelial growth factor A expression which modulates symptoms of chronic inflammatory diseases. RCM intake also significantly increased hypoxia inducible factor 3, alpha which is the negative regulators of hypoxia-inducible gene expression. Furthermore, only unripe RCM reduced chemokine (C-C motif) ligand 8, chemokine (C-X-C motif) ligand 14, and phospholipase A2 expression. In this study, we showed that RCM had anti-inflammatory effects by suppression of pro-inflammatory mediator expressions and may reduce chronic inflammatory disease progress through regulation of gene expressions. These findings suggest that RCM might be used as a potential functional material to reduce chronic inflammatory responses.