• Title/Summary/Keyword: Exogenous factor

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The Effects of PDGF and LPS on the Viability of Human Periodontal Ligament Cells (PDGF와 LPS가 치주 인대 세포의 활성에 미치는 영향에 관한 연구)

  • Heo, Jeong;Lim, Jeong-Hyun;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.28 no.1 s.66
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    • pp.143-153
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    • 1998
  • Platelet-derived growth factor(PDGF) and lipopolysaccharide(LPS) may be the important regualtors of bone metabolism Exogenous PDGF is recognized to have a stimulating effect on bone resorption in organ culture but to stimulate the formation of new bone ultimately. LPS is known to be a stimulating agent on the osteoclastic activity. The purpose of this study was to evaluate the effects and the interaction of PDGF and LPS on periodontal ligament(PDL) cells which have important roles in bone remodeling. Cultured human periodontal ligament cells were tented with various concentration or PDGF and/or LPS. The cellular viability was measured by Microtitration(MTT) assay according to the lapse time of culture. The obtained results were as follows: 1. The viability of PDL cells was not different from the con01 in 0.1ng/ml of PDGF, but was significantly increased to be over the level of control in 1ng/ml of PDGF at the second day of culture, and in 10ng/m1 of PDGF at the second and the third day of culture. 2. The cellular viability was decreased in $0.5{\mu}g/ml$ or $5{\mu}g/ml$ LPS at the third day of culture. 3. Incubation with both 1ng/ml or 10ng/ml of PDGF and $0.5{\mu}g/ml$ of $5{\mu}g/ml$ of LPS resulted in the increased cellular viability at the third day, which was greater than LPS only treated group. It was greater than even the control group in 10ng/m1 of PDGF. From the above findings, we could summarize that the admixture of PDGF and LPS could not less increase the viability of the human periodontal ligament cells than PDGF only.

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Effects of Long Term Exogenous Bovine Somatotropin on Nutrients Uptake by the Mammary Gland of Crossbred Holstein Cattle in the Tropics

  • Chaiyabutr, Narongsak;Thammacharoen, S.;Komolvanich, S.;Chanpongsang, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.9
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    • pp.1407-1416
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    • 2007
  • Ten, first lactation, 87.5%HF dairy cattle were used to investigate effects of long-term administration of recombinant bovine somatotropin (rbST) on nutrient uptake by the mammary gland at different stages of lactation. Measurements of arterial plasma concentrations and arterial-venous differences of metabolites across the mammary gland were performed in combination with measurment of mammary blood flow to estimate the mammary uptake. Animals in experimental groups were injected subcutaneously every 14 days from day 60 of lactation with a prolonged-release formulation of 500 mg of rbST (POSILAC, Monsanto, USA) or with sterile sesame oil without rbST in the control group. During early lactation, the milk yield of rbST-treated animals was higher than that of the control animals (p<0.05). The peak milk yield in both groups of animals declined from the early period of lactation with progression to mid- and late-lactation. No significant changes were observed in the concentration of milk lactose, while the concentrations of milk protein significantly increased as lactation advanced to mid- and late-lactation in both groups. Milk fat concentrations were significantly higher in rbST-treated animals than in control animals, particularly in early lactation (p<0.05). Mammary blood flow (MBF) markedly increased during rbST administration and was maintained at a high level throughout lactation. The mean arterial plasma concentrations for glucose and acetate of rbST-treated animals were unchanged. The net mammary glucose uptake of rbST-treated animals increased approximately 20% during early lactation, while it significantly decreased (p<0.05), including the arteriovenous differences (A-V differences) and extraction ratio across the mammary gland, as lactation advanced to mid- and late-lactation. A-V differences, mammary extraction and mammary uptake for acetate increased during rbST administration and were significantly higher (p<0.05) than in the control animals in early and mid-lactation. Mean arterial plasma concentrations for ${\beta}$-hydroxybutyrate and free glycerol were unchanged throughout the experimental periods in both groups. A-V differences and extraction ratio of ${\beta}$-hydroxybutyrate across the mammary gland did not alter during rbST administration. Mean arterial plasma concentrations for free fatty acids ($C_{16}$ to $C_{18}$), but not for triacylglycerol, increased in rbST-treated animals and were significantly higher than in control animals during early lactation (p<0.01). These findings suggest that an increase in MBF during rbST administration would not be a major determinant in the mediation of nutrient delivery and uptake by the mammary gland for increased milk production. Local changes in biosynthetic capacity within the mammary gland would be a factor in the utilization of substrates resulting in the rate of decline in milk yield with advancing lactation.

Driving Satisfaction and Safety Assessment for Roundabout (회전교차로 주행 만족도 및 안전성 평가)

  • Namgung, Moon;Shin, Hoe Sik;Jang, Tae Youn
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.223-233
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    • 2014
  • This study empirically analyzes the relationships among the road and traffic experts' personal characteristics, the driving behavior and factors being expected to have an effect on the satisfaction about roundabout operation. The factors are drawn and grouped through the principle component analysis to clarify driving environment satisfaction on roundabout operation. Each group is named as personal attribute, driving behavior attribute, and satisfaction. After the variables are refined by confirmatory factor analysis, satisfaction model is developed with personal attribute and driving behavior attributes as exogenous variables and roundabout driving awareness and emotion attributes as endogenous variables. As a result, driving satisfaction of roundabout operation is directly influenced by delay reduction, safety improvement, capacity increase, sight improvement, severity accident reduction, and bicycle convenience and indirectly gender, age, driving time, and driving experience. Law obeyance, driving concession, traffic sign obeyance, and interposition do not statistically shows significant on satisfaction. As a result of Analytical Hierarchy Process (AHP), the turning radius of geometry and the driving behavior are important elements for roundabout safety.

Study on 『BianZhengGiMun)』's medical characteristics - In view of ShangHan - (『변증기문(辨證奇聞)』의 의학적(醫學的) 특징(特徵)에 관(關)한 고찰(考察) -상한문(傷寒門)을 중심(中心)으로-)

  • Lee, Won-Suk;Park, Sun-Dong;Park, Won-Hwan;Kim, Jun-Ki;Kim, Jong-Dae
    • The Journal of Dong Guk Oriental Medicine
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    • v.6 no.2
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    • pp.33-85
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    • 1998
  • In order to find the characteristic medical methods of "BianZhengGiMun" by the author ChenShihTo, we have translated and analyzed the mentioned book. Upon analyses, the following facts were noted : 1) "BianZhengGiMun" is written and composed of case studies. Prescriptive methods described here differ rather from previously known methods, where as our nation's Oriental medicine practitioners refer and consider these methods as miraculous modern methodologies. 2) Book's content has much similarities to "ShangHanLun"'s original text. Moreover, the content is adjusted towards presenting methodologies not coverd in "ShangHanLun"'s text, together with adding more information to conserve "ShangHanLun"'s methods as well as to critique them. 3) Diagnostic methods mainly follow the ZangFuBianZheng(臟腑辨證)'s pattern, where it's recorded information and theories are valid. 4) "BianZhengGiMun"'s proscriptive methods usually follow BuYinShengJin(補陰生津)'s form, where they were appropriate for that period and circumstances. 5) In consideration of all of the above factors, ChenShihTo grasped ShangHan and WenBing(acute febrile disease due to exogenous factor) as WaiGanReBing(外感熱病)'s double sided characteristics, where this corresponds with the current belief. It is believed that this in turn would provide much practical value to the present time.

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Prostaglandin E2 Reverses Curcumin-Induced Inhibition of Survival Signal Pathways in Human Colorectal Carcinoma (HCT-15) Cell Lines

  • Shehzad, Adeeb;Islam, Salman Ul;Lee, Jaetae;Lee, Young Sup
    • Molecules and Cells
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    • v.37 no.12
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    • pp.899-906
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    • 2014
  • Prostaglandin $E_2$ ($PGE_2$) promotes tumor-persistent inflammation, frequently resulting in cancer. Curcumin is a diphenolic turmeric that inhibits carcinogenesis and induces apoptosis. $PGE_2$ inhibits curcumin-induced apoptosis; however, the underlying inhibitory mechanisms in colon cancer cells remain unknown. The aim of the present study is to investigate the survival role of $PGE_2$ and whether addition of exogenous $PGE_2$ affects curcumininduced cell death. HCT-15 cells were treated with curcumin and $PGE_2$, and protein expression levels were investigated via Western blot. Reactive oxygen species (ROS) generation, lipid peroxidation, and intracellular glutathione (GSH) levels were confirmed using specific dyes. The nuclear factor-kappa B ($NF-{\kappa}B$) DNA-binding was measured by electrophoretic mobility shift assay (EMSA). $PGE_2$ inhibited curcumin-induced apoptosis by suppressing oxidative stress and degradation of PARP and lamin B. However, exposure of cells to the EP2 receptor antagonist, AH6809, and the PKA inhibitor, H89, before treatment with $PGE_2$ or curcumin abolished the protective effect of $PGE_2$ and enhanced curcumin-induced cell death. $PGE_2$ activates PKA, which is required for cAMP-mediated transcriptional activation of CREB. $PGE_2$ also activated the Ras/Raf/Erk pathway, and pretreatment with PD98059 abolished the protective effect of $PGE_2$. Furthermore, curcumin treatment greatly reduced phosphorylation of CREB, followed by a concomitant reduction of $NF-{\kappa}B$ (p50 and p65) subunit activation. $PGE_2$ markedly activated nuclear translocation of $NF-{\kappa}B$. EMSA confirmed the DNA-binding activities of $NF-{\kappa}B$ subunits. These results suggest that inhibition of curcumin-induced apoptosis by $PGE_2$ through activation of PKA, Ras, and $NF-{\kappa}B$ signaling pathways may provide a molecular basis for the reversal of curcumin-induced colon carcinoma cell death.

Study on Epidermal Growth Factor (EGF) and Expression of EGF-Receptor (EGF-R) in Mouse IVF/IVC Embryo;II. Expression of EGF-R on the Inner Cell Mass (ICM) of Mouse IVF/IVC Blastocyst (체외생산된 생쥐배에 대한 EGF와 EGF-R 발현에 관한 연구;II. 체외생산된 생쥐 배반포기배 ICM세포에서의 EGF-R 발현)

  • Kim, E.Y.;Kim, M.K.;Yoon, S.H.;Park, S.P.;Chung, K.S.;Lim, J.H.
    • Clinical and Experimental Reproductive Medicine
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    • v.24 no.1
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    • pp.21-26
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    • 1997
  • This study was undertaken to examine the expression of EGF-R protein on ICM obtained from mouse IVF/IVC blastocyst by immunosurgery and indirect immunofluorescence(IIF). ICM cells used for this experiment were obtained from immunosurgery of mouse blatstocysts produced at 96 h after IVF, and recovered ICMs were assayed for cell viability and expression of EGF-R. The results obtained in this experiment were summarized as follows: when blastocysts were exposed to rabbit anti-mouse serum (antiserum) for 15-30 min. and then transferred them to guinea pig serum (complement) for 15-60 min., recovery rates of isolated ICMs were 8.0-84.2%. Especially, the best recovery (84.2%) of ICMs was obtained when exposure time to antiserum and complement was 30 min. and 60 min., respectively. In addition, when viability of isolated ICMs after immunosurgery was assessed by live/dead staining method, in all groups viability (93.8-100.0%) of isolated ICMs were not damaged if separated from TE cell. Also, we detected the expression of EGF-R on ICM cell by IIF. Therefore, these results suggest that EGF-R expression on the ICMs can stimulate the higher usablity of exogenous EGF to improve the preimplantation embryo development in vitro.

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Human Lung Insults due Air Pollutant -A Review for Priority Setting in the Research- (대기오염에 의한 폐장조직 손상 -연구방향의 설정을 위한 논의-)

  • 김건열;백도명
    • Journal of environmental and Sanitary engineering
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    • v.7 no.2
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    • pp.95-110
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    • 1992
  • Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.

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[ $P2X_2$ ] Receptor Activation Potentiates PC12 Cell Differentiation Induced by ACAP in Acidic Environments

  • Lee, Myung-Hoon;Nam, Jin-Sik;Ryu, Hye-Myung;Yoo, Min;Lee, Moon-Hee
    • Biomedical Science Letters
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    • v.13 no.3
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    • pp.197-206
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    • 2007
  • P2X receptors are membrane-bound ion channels that conduct $Na^+,\;K^+$, and $Ca^{2+}$ in response to ATP and its analogs. There are seven subunits identified so far ($P2X_1-P2X_7$). $P2X_2$ receptors are known to be expressed in a wide range of organs including brains and adrenal grands. PC12 cells are originated from adrenal grand and differentiated by nerve growth factor or pituitary adenylate cyclase activating poly peptide (PACAP). Previous studies indicate that $P2X_2$ receptor activation in PC12 cells couples to $Ca^{2+}-dependent$ release of catecholamine and ATP. It is known that acidic pH potentiates ATP currents at $P2X_2$ receptors. This leads to a hypothesis that $P2X_2$ receptors may play an important role in PC12 cell differentiation, one of the characteristics of which is neurite outgrowth, induced by the hormones under lower pH. In the present study, we isolated several clones which potentiate neurite outgrowth by PACAP in acidic pH (6.8), but not in alkaline pH (7.6). RT-PCR and electrophysiology data indicate that these clones express only functional $P2X_2$ receptors in the absence or presence of PACAP for 3 days. Potentiation of neurite outgrowth resulted from PACAP (100 nM) in acidic pH is inhibited by the two P2X receptor antagonists, suramin and PPADS ($100\;{\mu}M)$ each), and exogenous exprerssion of ATP-binding mutant $P2X_2$ receptor subunit ($P2X_2[K69A]$). However, acid sensing ion channels (ASICs) are not involved in PACAP-induced neurite outgrowth potentiation in lower pH since treatments of an inhibitor of ASICs, amyloride ($10\;{\mu}M$), did not give any effects to neurite extension. The vesicular proton pump ($H^+-ATPase$) inhibitor, bafilomycin (100 nM), reduced neurite extension indicating that ATP release resulted from $P2X_2$ receptor activation in PC12 cells is needed for neurite outgrowth. These were confirmed by activation of mitogen activated protein kinases, such as ERKs and p38. These results suggest roles of ATP and $P2X_2$ receptors in hormone-induced cell differentiation or neuronal synaptogenesis in local acidic environments.

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Roles of CYP1A1 and CYP2E1 Gene Polymorphisms in Oral Submucous Fibrosis

  • Yaming, Punyo;Urs, Aadithya Basavaraj;Saxena, Alpana;Zuberi, Mariyam
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3335-3340
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    • 2016
  • Background: Oral submucous fibrosis (OSF) is a precancerous condition with a 4 to13% malignant transformation rate. Related to the habit of areca nut chewing it is mainly prevalent in South-east Asian countries where the habit of betel quid chewing is frequently practised. On chewing, alkaloids and polyphenols are released which undergo nitrosation and give rise to N-nitrosamines which are cytotoxic agents. CYP450 is a microsomal enzyme group which metabolizes various endogenous and exogenous chemicals including those released by areca nut chewing. CYP1A1 plays a central role in metabolic activation of these xenobiotics, whereas CYP2E1 metabolizes nitrosamines and tannins. Polymorphisms in genes that code for these enzymes may alter their expression or function and may therefore affect an individuals susceptibility regarding OSF and oral cancer. The present study was therefore undertaken to investigate the association of polymorphisms in CYP1A1 m2 and CYP2E1 (RsaI/PstI) sites with risk of OSF among areca nut chewers in the Northern India population. A total of 95 histopathologically confirmed cases of OSF with history of areca nut chewing not less than 1 year and 80, age and sex matched controls without any clinical signs and symptoms of OSF with areca nut chewing habit not less than 1 year were enrolled. DNA was extracted from peripheral blood samples and polymorphisms were analyzed by PCR-RFLP method. Gene polymorphism of CYP1A1 at NcoI site was observed to be significantly higher (p = 0.016) in cases of OSF when compared to controls. Association of CYP1A1 gene polymorphism at NcoI site and the risk of OSF (Odd's Ratio = 2.275) was also observed to be significant. However, no such association was observed for the CYP2E1 gene polymorphism (Odd's Ratio = 0.815). Our results suggest that the CYP1A1 gene polymorphism at the NcoI site confers an increased risk for OSF.

Relation of Career Barriers, Career Decision Efficacy and Career Preparation Behavior among Under Graduate Students of Private Security Guard Major (경호전공 대학생의 진로장벽과 진로결정효능감 및 진로준비행동의 관계)

  • Kim, Kyong-Sik;Kim, Chan-Sun
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.404-414
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    • 2013
  • This study establishes structure pattern about private security guard major under graduate students career preparation conduct and reality adaptability wishes to deduce high theoretical pattern. Then, I wish to verify causality of variables included in pattern. This study established private security guard major of 3 university by population to Seoul, Gyeonggi Province in 2012. Using purposive sampling method, 130 samples were drawn and were used for the final analysis. Validity and reliability of questionnaire verified to be through confirmatory factor analysis and reliability analysis. Validity of questionnaire came out to be over exogenous variable value .664, endogenous variable value .787. In this study, utilizes AMOS 18.0 and SPSS WIN 18.0 programs for reliability analysis and took advantage of technique of covariance structure analysis. The conclusion is following : First, private security guard major self-clearness shortage exerts contradictory influence on career decision efficacy. Second, private security guard major self-clearness shortage does not affect on career preparation behavior. Third, problem about private security guard major age exerts contradictory influence on career decision efficacy. Fourth, problem about private security guard major age does not affect on career preparation behavior. Fifth, physical inferiority complex of a private security guard major does not affect in career decision efficacy. Sixth, physical inferiority complex of a private security guard major does not affect on career preparation behavior. Seventh, private security guard major course decision efficacy affects on career preparation behavior.