• Journal of Life Science
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• v.20 no.3
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• pp.321-325
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• 2010

Among endogenous oral microflora, Streptococcus mutans plays a critical role in dental plaque formation, which mainly contributes to the development of caries and periodontal disease. Phytochemicals are plant-derived chemical compounds that have been studied as beneficial nutrients to human health. The purpose of this study was to determine the effects of phytochemicals against S. mutans. Among them, oleanolic acid (OA) and 5-(hydroxymethyl)-2-furfural (HF) from Thomson seedless raisins were tested for anti-microbial effects against various clinically important bacteria. OA inhibited the growth of Gram-positive bacteria, but not Gram-negative bacteria. However, HF did not display any antibacterial effect against any of the strains tested. OA also exhibited inhibitory effects in surface adherence and biofilm formation of S. mutans. The results suggest that OA can be utilized as a potential anti-plaque and anti-caries agent by controlling the physiological characteristics of S. mutans on teeth.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.1-8
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• 1993

To elucidate involvement of platelet-activating factor (PAF) in cerebral ischemia-reperfusion injury, male Sprague-Dawley rats and albino mice of either sex were subjected to a 10-min bilateral carotid artery occlusion and 6-hr recirculation. The McGraw stroke index in mice was markedly inhibited by PAF antagonists, BN 52021 and CV 6209 (1 mg/kg, i.p., each) When they were administered 10 min before bilateral carotid artery occlusion or 1 hr after reperfusion. The increases in brain water content were significantly attenuated by treatment with BN 52021 or CV 6209 in both animals. BN 52021 exhibited a significant improvement in the postischemic blood pressure change in association with a beneficial effect on the delayed dilatation of pial arterioles after 10 min of ischemia. Thus it is suggested that PAF plays an important role as an endogenous mediator in development of cerebral ischemia-reperfusion injury, and further, specific antagonists to PAF will be able to prevent or reverse the pathological sequelae of cerebral ischemia.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.55-55
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• 2003

P2X$_3$ receptor, a member of P2 purine receptors, is a ligand-gated ion channel activated by extracellular ATP as an endogenous ligand, and highly localized in peripheral and central sensory neurons. The activation of P2X3 receptor by ATP as the pronociceptive effect has been known to initiate the pain signaling involved in chronic inflammatory nociception and neuropathic pain by nerve injury, implicating the possibility of new drug development to control pains. In this study, we have developed a two electrode voltage clamp (TEVC) assay system to evaluate the inhibitory activity of several newly synthesized PPADS and a novel non-ionic antagonist against ATP activation of human P2X3 receptor. PPADS derivatives include several pyridoxine and pyridoxic acid analogs to study the effects of phosphate and aldehyde functional groups in PPADS. All new PPADS analogs were less potent than PPADS at human P2X$_3$ receptors, however, LDD130, a non-ionic analog showed potent antagonistic property with $IC_{50}$/ of 8.34 pM. In order to uncover the structure activity relationships of LDD130, and design new structural analogs, we synthesized and investigated a few structural variants of LDD130, and the results will be discussed in this presentation.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.197-201
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• 2007

Genistein is an active component of legumes and other related food shown to be associated with prevention of degenerative diseases such as cancer through inducing signaling pathways. Treatment of genistein resulted in the induction of apoptosis in the cultured cancer cells. This induction of apoptosis was demonstrated by the Tunel assay in these cells. Unveiling the potential of genistein in cytotoxicity via apoptosis when it is treated with estrogen can predict the therapeutic capability of genistein in breast cancers in the presence of endogenous estrogen. We have found that apoptosis induced by genistein treatment in the presence of estrogen is agonistic or antagonistic depending on the concentrations and treatment periods applied in MCF-7 breast cancer cells. For the suppression of cell survival, 24 hr of treatment was required to induce a synergistic agonistic response between estrogen and genistein at low concentrations of genistein. After this period, the agonistic pattern of genistein to estrogen disappeared. The decrement of COX-2 expression in MCF-7 cells treated with genistein was accompanied with the activation of AMPK only at a high concentration of genistein. This association between AMPK activation and down-regulation of COX-2 by genistein was dampened in the presence of estrogen. It was also demonstrated that genistein and estrogen regulate cell survival and apoptosis by modulating p53 and caspase-3 in the opposite direction. These results suggest that genistein has the potential to control breast cancer development, and co-treatment with estrogen can cause agonistic or antagonistic action on breast cancer cell control.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1978.06a
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• pp.8.2-8
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• 1978

This paper was designed to investigate the causes of child hearing loss which is essential to language development especialy in young childhood. Accurate history taking, precise otolaryngological examination and impedence audiometry were performed on 185 hard of hearing children under age 5 during last 8 months and investigated its causes. The results were as follows: 1. Infections diseases were the most common causes of sensorineural hearing loss (44/123cases, 30.1%), and mother's condition during pregnancy the second, and birth injury or head trauma the third. 2. Acute or chronic ear ear diseases were the most common causes of counductive hearing loss (32/62, 51.6%), frequent URI the second (19/62, .30.6%), and adenoid vegetation the third (7/62, 11.3%). 3. The majority of causes of child hearing loss under age 5 was exogenous (179/185 cases, 96.8%), and the minority was endogenous (6/185 cases, 3.2%).

• Korea Journal of Hospital Management
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• v.7 no.4
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• pp.123-151
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• 2002

The objective of this study is to analyze the causal relationship of hospital inpatient's perceived quality, overall satisfaction, service value, and future intention to revisit. To carry out this objective, first we analyzed the dimensions of inpatient care service quality using SERVQUAL scale. The SERVQUAL scale is based on the gap theory, that is, the difference of patients' expectations and the actually received medical care service in hospital. On the basis of this theory, we measured the inpatient's perceived service quality and overall patient satisfaction. Data was gathered from a self-administered questionnaire at a 980 bed university hospital in Inchon City. These questionnaire measuring the service quality were distributed to 250 inpatients. The response rate was 66.4%. A total of 166 questionnaires was finally analyzed. To categorize medical service quality, the factor analysis was performed on 42 items. The reliability and validity of these items was evaluated. Finally to test 6 hypotheses, we analyzed the causal relationship of service quality, overall satisfaction, service value, and intention to revisit through the structural equation modeling(SEM). The major results of this study are as follows. First, the dimension of inpatient service quality was categorized into 7 dimensions, that is, personal caring, communication, access, physical environment, facilities and equipment, cleanliness, appropriateness and health status. Second, the reliability and validity of inpatient service quality items was satisfied. Third, as a result of structural equation modeling, the effect of inpatient's perceived service quality on overall satisfaction, service value, and intention to revisit was statistically significant. And total effect on intention to revisit as the core endogenous variable was perceived service quality(1.100), patient satisfaction(0.006), and service value(0.605).

• Journal of Veterinary Clinics
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• v.25 no.6
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• pp.458-465
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• 2008

The purpose of this study is to characterize canine mesenchymal stem cells (MSCs) derived from bone marrow (BM) for use in research on the applications of stem cells in canine models of development, physiology, and disease. BM was harvested antemortem by aspiration from the greater tubercle of the humerus of 30 normal beagle dogs. Canine BM-derived MSCs were isolated according to methods developed for other species and were characterized based on their morphology, growth traits, cell-surface antigen profiles, differentiation repertoire, immunocytochemistry results, and neurotrophic factor expression in vitro. The canine MSCs exhibited a fibroblast-like morphology with a polygonal or spindle-shaped appearance and long processes; further, their cell-surface antigen profiles were similar to those of their counterparts in other species such as rodents and humans. The canine MSCs could differentiate into osteocytes and neurons on incubation with appropriate induction media. RT-PCR analysis revealed that these cells expressed NGF, bFGF, SDF-1, and VEGF. This study demonstrated that isolating canine MSCs from BM, stem-cell technology can be applied to a large variety of organ dysfunctions caused by degenerative diseases and injuries in dogs. Furthermore, our results indicated that canine MSCs constitutively secrete endogenous factors that enhance neurogenesis and angiogenesis. Therefore, these cells are potentially useful for treating dogs affected with various neurodegenerative diseases and spinal-cord injuries.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.721-727
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• 2007

Scorpion (SCP) has been clinically used for the treatment of endogenous wind to relieve convulsion, clearing away toxins, resolving hard masses and removing obstruction in the collaterals to relieve pain. Recent studies showed that scorpion toxins that affect the activating mechanism of sodium channels and indian black scorpion venom induced anti-proliferative and apoptogenic activity against human leukemic cell lines U937 and K562. There is lack of studies regarding the effects of SCP on the immunological activities. The present study was conducted to evaluate the effect of SCP on the regulatory effects of cytokines and nitric oxide (NO) for the immunological activities in Raw 264.7 cells. After the treatment of SCP MeOH extract dissolved in media for 1 h prior to the addition of lipopolysaccharide (LPS: 1 ${\mu}$g/ml), cell viability was measured by MTT assay, NO production was monitored by measuring the nitrite content in culture medium. Inducible nitric oxide synthase (iNOS) was determined by immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. As results, SCP inhibited the production of nitrite and nitrate (0.3 and 1.0 mg/ml), iNOS and p-$I_KB_{\alpha}$ protein, tumor necrosis factor-${\alpha}$ (0.3 and 1.0 mg/ml), interleukin-1${\beta}$ (0.3 and 1.0 mg/ml) and interleukin-6 (1.0mg/ml) in Raw 264.7 cells activated with LPS. These findings suggest that SCP can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.205-213
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• 2003

Various angiogenesis inhibitors target vascular endothelial cells and block tumor angiogenesis. Angiostatin is a specific endogenous angiogenesis inhibitor in clinical trials, which contains only the first four triple loop structures, known as kringle domains. Its generated by proteolytic cleavage of its parent molecule plasminogen, which itself does not exhibit antiangiogenic activity. Kringle domains from prothrombin, apolipoprotein, hepatocyte growth factor, urokinase and tissue-type plasminogen activator also elicit anti-angiogenic or antitumor activities in several model systems, albeit low amino acid sequence identity between angiostatin and each individual kringle. However, the differential effects of each kringle domain on endothelial cell proliferation, and migration observed in these kringle domains, suggest that the amino acid sequence of the primary structure is still important although kringle architecture is essential for anti-mlgiogenic activity. If it is further studied as to how amino acid sequence and kringle architecture contributes in anti-angiogenic activity, with studies on underlying mechanisms of anti-angiogenesis by kringle-based angiogenesis inhibitors, it will provide basis for the development of new potent anti-angiogenesis inhibitors and improvement of the efficacy of angiogenesis inhibitors.

• Molecules and Cells
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• v.27 no.4
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• pp.417-422
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• 2009

Lipoxygenase (LO) metabolites are generated in inflamed tissues. However, it is unclear whether the inhibition of the LO activity regulates the expression of c-Fos protein, a pain marker in the spinal cord. Here we used a carrageenan-induced inflammation model to examine the role of LO in the development of c-Fos expression. Intradermally injected carrageenan caused elevated number of cells exhibiting Fos-like immunoreactivity (Fos-LI) in the spinal dorsal horn, and decreased the thermal and mechanical threshold in Hargreaves and von Frey tests. Pretreatment with an inhibitor of phospholipase A2, that generates the LO substrate, prior to the carrageenan injection significantly reduced the number of Fos-(+) cells. A general LO inhibitor NDGA, a 5-LO inhibitor AA-861 and a 12-LO inhibitor baicalein also exhibited the similar effects. Moreover, the LO inhibitors suppressed carrageenan-induced thermal and mechanical hyperalgesic behaviors, which inidcates that the changes in Fos expression correlates with those in the nociceptive behaviors in the inflamed rats. LO products are endogenous TRPV1 activators and pretreatment with BCTC, a TRPV1 antagonist inhibited the thermal but not the mechanical hypersensitivity. Overall, our results from the Fos-LI and behavior tests suggest that LO products released from inflamed tissues contribute to nociception during carrageenan-induced inflammation, indicating that the LO pathway is a possible target for modulating inflammatory pain.