72 results on '"Sang-Keun Kim"'
Search Results
2. Star Fishing
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Sang-Keun Kim and Sang-Keun Kim
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- Picture books, Fantasy fiction, Fiction, Juvenile works, Forest animals--Juvenile fiction, Bedtime--Juvenile fiction, Dreams--Juvenile fiction, Stars--Juvenile fiction, Bedtime--Fiction
- Abstract
A sleepless night turns into a marvelous adventure through the stars in this dreamy bedtime storyIt's the kind of night when you just can't fall asleep.You feel as though everyone in the world is asleep but you. “Oh, I see a light!Is somebody awake?” Brimming with wonder and enchantment, award-winning author-illustrator Sang-Keun Kim's Star Fishing imagines who else might be awake on a sleepless night—taking young readers and listeners on an adventure through the stars and into sweet dreams.
- Published
- 2022
3. 'I am not Aeneas, am not Paul' Studia Humanitatis and The Reformation, and The Future of Korean Church
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Sang Keun Kim
- Published
- 2017
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4. Effect of a Caregiver's Education Program on Stroke Rehabilitation
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Tae Hyun Kim, Sang-Keun Kim, Han Young Jung, Chang-Hwan Kim, Eui-Chang Lee, Ee-jin Kim, Sang-Eun Hong, Kyung-Lim Joa, and Hee-Jun Han
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030506 rehabilitation ,medicine.medical_specialty ,Barthel index ,medicine.medical_treatment ,Burnout ,Rehabilitation outcome ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Medicine ,Stroke ,Rehabilitation ,Stroke scale ,business.industry ,Rehabilitation counseling ,medicine.disease ,University hospital ,Caregiver ,Berg Balance Scale ,Physical therapy ,Original Article ,0305 other medical science ,business ,030217 neurology & neurosurgery - Abstract
Objective To evaluate effects of caregiver's education program on their satisfaction, as well as patient functional recovery, performed in addition to daily conventional rehabilitation treatment. Methods Three hundred eleven subjects diagnosed with first-onset stroke and transferred to the Department of Physical Medicine and Rehabilitation of Inha University Hospital were surveyed. In 2015, caregivers attended an education program for acute and subacute stroke patients. Patients who received an additional rehabilitation therapy were assigned to the experimental group (n=81), whereas the control group (n=100) consisted of transfer cases in 2014 with only conventional treatment. The experimental group was classified by severity using the Korean version of the National Institutes of Health Stroke Scale (K-NIHSS), which was administered to all 181 subjects, in addition to, the Korean version of the Mini Mental Status Examination (K-MMSE), a Modified Barthel Index (K-MBI), and the Berg Balance Scale (K-BBS). Caregiver satisfaction and burden before and after education programs were assessed using the Canadian Occupational Performance Measure (COPM), as well as family burden and caregiver burnout scales. Results No significant intergroup difference was observed between initial K-NIHSS, K-MMSE, K-BBS, K-MBI scores, and times from admission to transfer. Those with moderate or severe strokes under the experimental condition showed a more significant improvement than the control group as determined by the K-NIHSS and K-BBS, as well as tendential K-MMSE and K-MBI score increases. Satisfaction was significantly greater for family members and formal caregivers of patients with strokes of moderate severity in the experimental group. Conclusion The caregiver's education program for stroke subjects had a positive outcome on patients' functional improvement and caregiver satisfaction. The authors believe that the additional rehabilitation therapy with the education program aids patients to achieve functional improvements for an optimal return to social life.
- Published
- 2017
5. Development of planar active phased array antenna for detecting and tracking radar
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Sung-Moon Jang, Hyun Ok Kim, Hyung-Seok Jin, Sungjin Park, Dong-Yoon Kim, Min-Kil Chong, Ki-Ho Kim, Sang-Hyun Chun, and Sang-Keun Kim
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Signal processing ,Phased array ,Computer science ,Acoustics ,010401 analytical chemistry ,Beam steering ,020206 networking & telecommunications ,02 engineering and technology ,Effective radiated power ,01 natural sciences ,0104 chemical sciences ,law.invention ,law ,Side lobe ,0202 electrical engineering, electronic engineering, information engineering ,Antenna (radio) ,Radar ,Blanking - Abstract
In this Paper, describes development of C-band Planar Active Phase Array antenna for Detecting and Tracking the target of small RCS. The antenna is designed with 14 sub-arrays (12 main and 2 side lobe blanking, about 3000 elements of transmit-receive unit) to properly synthesized transmit and receive pattern. Using a near-field measurements chamber, measured transmit pattern and Effective Isotropic Radiated Power (EIRP), also measured receive pattern and G/N. Receive pattern is implemented with Digital Beam Forming (DBF) by signal processing. The result of measurements shows a good agreement with Antenna design Specification.
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- 2018
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6. 'What has Decapolis to Do with Jerusalem?': A Missiological Interpretation of the Miracle of the Swine, Mark 5:1-20
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Sang Keun Kim
- Subjects
Philosophy ,Miracle ,media_common.quotation_subject ,Interpretation (philosophy) ,Ancient history ,media_common - Published
- 2015
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7. Development and efficiency of filter device for the emission reduction from the diesel engine in fishing boat
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Seong-Wook Park, Yongsu Yang, Sang-Keun Kim, Kyounghoon Lee, and Seong Hun Kim
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Environmental engineering ,Diesel engine ,Automotive engineering ,Mathematics - Abstract
온실가스의 발생량은 산업의 발달과 함께 증가하였으며 , 산업에서의 생산량과 비례하여 증가한다 . 수산업이전체 산업 중상대적으로 적은 부분을 차지하고 있으나, 우리나라 수산업 생산량 규모는 2006 년세계 13 위,수출금액 세계 26 위에 있으며 , 과거 1989 년생산량 세계8위, 수출 세계 6위에 이른 적도 있다 . 2010 년농림어업생산액은 50 조9490 억원이며 , 이중 어업생산액은 7.4 조원을 차지하고 있다 . 어업에 종사하고 있는 어선의 수는2009 년기준 78,262 척이 등록되어 있다 . 연근해어업 어선은 총어선수의 70% 를차지하고 , 전체 어선의 크기에서는 43% 로가장 높은 비율을 차지하고 있다 . 한편 , 어선으로 분류되지 않는 선박은 2009 년12 월자료에 따르면전체 8,374 척이 등록되어 있으며 총톤수는13,916,563 GT 이다 . 어선은 일반 선박과 비교하여 총톤수에서 전체 선박 중4% 의비율을 차지하고 있으나 배의척수에서는 전체의 90% 를차지하고 있다 (NFRDI ,2012)우리나라 어선 총수에서 가장 많은 부분을 차지하는어선의 선령이 6-15 년사이에 밀집되어 있으며 , 이러한어선의 엔진 또한 노후화되어 있다 . 선단 규모로 조업을 하는 대형선망 , 기선저인망 등은 어획성능을 유지
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- 2014
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8. An experimental study on the pressure drop and heat transfer through straight and curved small diameter tubes
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Man Yeong Ha, Changmin Son, Ji Hwan Jeong, and Sang Keun Kim
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Pressure drop ,Materials science ,Mechanics of Materials ,Turbulence ,Mechanical Engineering ,Heat transfer ,Heat exchanger ,Mechanical engineering ,Mechanics ,Concentric tube heat exchanger ,Nusselt number ,Bar (unit) ,Shell and tube heat exchanger - Abstract
A tube type heat exchanger is often the only solution when minimum pressure loss is a requirement. In addition, small diameter tubes are preferable because of an increased heat transfer area within an acceptable pressure loss limit. The present work reports on both an analytic model and experimental results with regards to the pressure drop and heat transfer characteristics of compact straight, C-curved, and U-curved tubes. The inner diameter of the tube (D) for our selected heat exchanger type was 1.26 mm with a thickness of 0.12 mm and a total length of 150.8 D. For the experiment, pressurized nitrogen gas bottles were used rather than an air compressor system in order to simplify the test facility. Hence the pressure conditions were easily set at 10, 30, and 50 bar corresponding to a range of Reynolds numbers from 10000 to 50000. To elevate the air temperature outside the tube (from 100°C to 400°C), an electric furnace was installed around the “test tube”. An analytic model to determine the pressure loss through curved tubes-referred to as the modified friction factor- is proposed. Good agreement was found between the modified friction factor and existing correlations, thus confirming the suitability of this model for determining pressure losses for different shape of tubes. The average measured Nusselt numbers were within 10- 15% of the Dittus-Boelter and Gnielinski correlations.
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- 2014
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9. Reduction of heavy metals and organic materials by atomized slag barrier in contaminated groundwater
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Jae-Suk Ryou, Jin-Young Kong, Byungsik Chun, Jong-Sik Park, Hyuk-Sang Jung, Yong-Joo Lee, and Sang-Keun Kim
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Pollutant ,Materials science ,Waste management ,Metallurgy ,Slag ,Heavy metals ,Field tests ,Waste product ,Permeable reactive barrier ,visual_art ,visual_art.visual_art_medium ,Ceramic ,Contaminated groundwater ,Civil and Structural Engineering - Abstract
Atomized slag is a residual waste product of steel manufacturing. The use of atomized slag as a recycled material is widespread in Korea, especially for filter media, ceramic filters, coagulate, construction materials, abrasives, and desulfurizing agents. The absorptivity of atomized slag as a reactive media for a permeable reactive barrier to eliminate pollutants inflowing from landfills was investigated in this study. Physical tests were performed to analyze the engineering properties of the atomized slag. The absorptive performance of the atomized slag against heavy metals and organics was examined in batch and column tests. Pilot-scaled and field tests were performed and monitored to evaluate the absorptivity of the atomized slag in the permeable reactive barrier against heavy metals and organics. The pilot-scaled test results showed the removal efficiencies of more than 94.9% for organics and more than 99.9% for heavy metals passing into the atomized media. The field test results indicated that the removal efficiencies of the atomized slag applied in the permeable reactive barrier were measured to be from 82 to 85% for organics and from 90 to 95% for heavy metals. The implications of the results are discussed.
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- 2013
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10. Mechanism of anti-platelet activity ofOligoporus tephroleucusoligoporin A: Involvement of extracellular signal-regulated kinase phosphorylation and cyclic nucleotide elevation
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In-Kyoung Lee, Suk Kim, Sang-Keun Kim, Tae-Hwan Kim, Won Jun Oh, Bong-Sik Yun, Gon-Seop Kim, Man Hee Rhee, Jae Youl Cho, Geon-Sik Seo, Hwa-Jin Park, Myung Jin Kim, and Ji Young Park
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Blood Platelets ,Male ,Platelet Aggregation ,Platelet Glycoprotein GPIIb-IIIa Complex ,Biology ,Rats, Sprague-Dawley ,Cyclic nucleotide ,chemistry.chemical_compound ,Glucosides ,Cell surface receptor ,Cyclic AMP ,Extracellular ,Animals ,Humans ,Platelet ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Cyclic GMP ,Kinase ,Fibrinogen ,Fibrinogen binding ,Hematology ,General Medicine ,Platelet Activation ,Triterpenes ,Rats ,Cell biology ,Adenosine Diphosphate ,chemistry ,Biochemistry ,Calcium ,Intracellular ,Signal Transduction - Abstract
This study investigated the inhibitory effects of oligoporin A on platelet aggregation and the mechanism of its action on downstream signaling molecules. Oligoporin A was isolated from the fruiting bodies of Oligoporus tephroleucus (Polyporaceae). The anti-platelet activities of oligoporin A were studied using rat platelets. The effects of oligoporin A on intracellular Ca(2+) mobilization, ATP release, production of the cyclic nucleotides cAMP and cGMP, extracellular signal-regulated kinase (ERK) 2 phosphorylation, and fibrinogen binding to active integrin α(II)(b)β(3) were assessed. Oligoporin A, but not oligoporins B and C, inhibited collagen-induced platelet aggregation in a concentration-dependent manner. Interestingly, oligoporin A did not affect ADP- and thrombin-induced platelet aggregations, which act on different types of membrane receptors. Granule secretion analysis demonstrated that oligoporin A significantly and dose-dependently reduced collagen-induced ATP release and intracellular Ca(2+) mobilization. Additionally, oligoporin A induced the dynamic increase in cAMP and cGMP. Increased cGMP production was further confirmed by the simultaneous production of nitric oxide. Pretreatment with oligoporin A significantly blocked collagen-induced ERK2 phosphorylation. Finally, oligoporin A vaguely diminished the binding of fibrinogen to its cognate receptor, integrin α(II)(b)β(3). The results indicate that oligoporin A inhibits only collagen-induced platelet aggregation mediated through the modulation of downstream signaling molecules. Oligoporin A may be beneficial against cardiovascular disease provoked by aberrant platelet activation.
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- 2012
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11. Korean Red Ginseng Saponin Fraction Downregulates Proinflammatory Mediators in LPS Stimulated RAW264.7 Cells and Protects Mice against Endotoxic Shock
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Sang-Keun Kim, Hye Yoon Jeong, Taddessee Yayeh, Ji-Hoon Park, Kun-Ho Jung, Jae Youl Cho, Heun-Soo Kang, Yi-Seong Kwak, Man Hee Rhee, Yong-Bum Song, and Jae-Wook Oh
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Lipopolysaccharide ,Pro-inflammatory cytokines ,Pharmacology ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Nitric oxide ,Proinflammatory cytokine ,chemistry.chemical_compound ,Ginseng ,20(S)-protopanaxadiol saponins ,medicine ,Endotoxic shock ,biology ,business.industry ,Monocyte ,Macrophages ,Panax ginseng ,Interleukin ,Articles ,Nitric oxide synthase ,medicine.anatomical_structure ,Complementary and alternative medicine ,chemistry ,Immunology ,biology.protein ,Tumor necrosis factor alpha ,business ,Biotechnology - Abstract
Korean red ginseng has shown therapeutic effects for a number of disease conditions. However, little is known about the anti- inflammatory effect of Korean red ginseng saponin fraction (RGSF) in vitro and in vivo. Therefore, in this study, we showed that RGSF containing 20(S)-protopanaxadiol type saponins inhibited nitric oxide production and attenuated the release of tumor necrotic factor (TNF)-α, interleukin (IL)-6, granulocyte monocyte colony stimulating factor (GMCSF), and macrophage chemo- attractant protein-1 in lipopolysaccharide (LPS) stimulated murine macrophage RAW264.7 cells. Moreover, RGSF down-regulated the mRNA expressions of inducible nitric oxide synthase, cyclooxyginase-2, IL-1β, TNF-α, GMCSF, and IL-6. Furthermore, RGSF reduced the level of TNF-α in the serum and protected mice against LPS mediated endotoxic shock. In conclusion, these results indicated that ginsenosides from RGSF and their metabolites could be potential sources of therapeutic agents against infl ammation.
- Published
- 2012
12. Design of AEM FSS-Radome for Array Antenna
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Il-Seong Seo, Sang-Keun Kim, and Gi-Tae Lee
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Engineering ,Optics ,business.industry ,law ,Transmission loss ,Tunable metamaterials ,Radome ,Radar ,business ,law.invention ,Radiation pattern - Abstract
In this paper, we present a design of AEM radome with frequency selective surface using unit-cell EM simulation method and verified the performance of AEM radome by the radiation pattern measurements of array-antenna. Measured results under near-field condition showed a good agreement with the simulation and far-field measured ones. And there were no radiation pattern variation between antenna only and antenna with AEM radome. From these results, we verified that AEM radome with frequency selective surface can be a solution to reduce the RCS of conventional mast and radar.
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- 2011
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13. A Numerical Study on the Heat Transfer Characteristics of the Multiple Slot Impinging Jet
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Man Yeong Ha, Changmin Son, and Sang-Keun Kim
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Jet (fluid) ,symbols.namesake ,Chemistry ,Heat transfer ,Flow (psychology) ,Nozzle ,symbols ,Thermodynamics ,Reynolds number ,Heat transfer coefficient ,Mechanics ,Stagnation point ,Nusselt number - Abstract
The present study numerically investigates two-dimensional flow and heat transfer in the multiple confined impinging slot jet. Numerical simulations are performed for the different Reynolds numbers(Re = 100 and 200) in the range of nozzles from 1 to 9 and height ratios(H/D) from 2 to 5, where H/D is the ratio of the channel height to the slot width. The vector plots of velocity profile, stagnation and averaged Nusselt number distributions are presented in this paper. The dependency of thermal fields on the Reynolds number, nozzle number and height ratio can be clarified by observing the Nusselt number as heat transfer characteristic at the stagnation point and impingement surface. The Nusselt number at the stagnation point of the central slot shows unsteadiness at H/D = 3 and Re = 200. The value of Nusselt number at the stagnation point of the central slot decreases with higher Reynolds number and number of nozzle although overall area averaged Nusselt number increases. Hence careful selection of geometrical parameters and number of nozzle are necessary for optimization of the heat transfer performance of multiple slot impinging jet.Keywords:Multiple slot impinging jet(다중충돌제트), Heat transfer(열전달)
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- 2011
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14. Phellinus baumii ethyl acetate extract inhibits lipopolysaccharide-induced iNOS, COX-2, and proinflammatory cytokine expression in RAW264.7 cells
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In-Kyoung Lee, Bong-Sik Yun, Seung-Choon Park, Man Hee Rhee, Jae Youl Cho, Taddesse Yayeh, Sang-Keun Kim, Seung-Bok Hong, Tae-Hwan Kim, Won Jun Oh, and Hwa-Jin Park
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Lipopolysaccharides ,Lipopolysaccharide ,Blotting, Western ,Interleukin-1beta ,Anti-Inflammatory Agents ,Nitric Oxide Synthase Type II ,Inflammation ,Acetates ,Nitric Oxide ,Dinoprostone ,Gene Expression Regulation, Enzymologic ,Cell Line ,Proinflammatory cytokine ,Nitric oxide ,Immunoenzyme Techniques ,Mice ,chemistry.chemical_compound ,Western blot ,medicine ,Animals ,RNA, Messenger ,Dose-Response Relationship, Drug ,medicine.diagnostic_test ,biology ,Interleukin-6 ,Reverse Transcriptase Polymerase Chain Reaction ,Macrophages ,Granulocyte-Macrophage Colony-Stimulating Factor ,Interleukin ,Molecular biology ,Reverse transcription polymerase chain reaction ,Nitric oxide synthase ,chemistry ,Biochemistry ,Cyclooxygenase 2 ,Solvents ,biology.protein ,Cytokines ,Molecular Medicine ,Medicine, Traditional ,Inflammation Mediators ,medicine.symptom ,Agaricales - Abstract
Mushrooms are valuable sources of biologically active compounds possessing anticancer, antiplatelet, and anti-inflammatory properties. Phellinus baumii is a mushroom used in folk medicine for a variety of human diseases. However, its potential anti-inflammatory effect has remained unclear. Therefore, we studied the effect of P. baumii ethyl acetate extract (PBEAE) on inflammatory mediator and proinflammatory cytokine protein and/or mRNA expression levels using the nitric oxide (NO) assay, enzyme immunoassay (EIA), western blot, and reverse transcription polymerase chain reaction (RT-PCR) in lipopolysaccharide (LPS)-stimulated macrophage like RAW264.7 cells. PBEAE markedly inhibited NO generation and prostaglandin E(2) (PGE(2)) synthesis in a concentration-dependent pattern without any cytotoxic effect at the concentration range used. PBEAE also suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. In addition, LPS-induced iNOS and COX-2 mRNA expression levels were dose-dependently inhibited by PBEAE pretreatment. Furthermore, PBEAE attenuated the mRNA expression levels of proinflammatory cytokines, specifically interleukin (IL)-1β, IL-6, and granulocyte macrophage colony-stimulating factor (GM-CSF), in a concentration-dependent fashion. Our study suggests that P. baumii might exhibit anti-inflammatory properties by downregulating proinflammatory mediators. Thus, further study on compounds isolated from PBEAE is warranted to investigate the associated molecular mechanisms and identify the potential therapeutic targets.
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- 2011
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15. Antiplatelet Activity of Phellinus baummii Methanol Extract is Mediated by Cyclic AMP Elevation and Inhibition of Collagen-activated Integrin-αIIb β3 and MAP Kinase
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Seung-Chun Park, Tae-Hwan Kim, Mehari Endale, Jae Youl Cho, Won-Jun Oh, Sang Keun Kim, In-Kyoung Lee, SM Kamruzzaman, Bong-Sik Yun, Man Hee Rhee, and Hwa-Jin Park
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Pharmacology ,MAPK/ERK pathway ,medicine.medical_specialty ,biology ,Chemistry ,Kinase ,Thrombin ,Endocrinology ,Internal medicine ,Mitogen-activated protein kinase ,medicine ,biology.protein ,Platelet ,Platelet activation ,Protein kinase A ,IC50 ,medicine.drug - Abstract
Phellinus baumii is a mushroom that has been used as folk medicine against various diseases and is reported to have antidiabetic, anticancer, antioxidant, antiinflammatory and antihypertensive activities. However, information on the effects of P. baumii extract in platelet function is limited. Therefore, the aim of this study was to examine the impact of a P. baumii methanol extract (PBME) on platelet activation and to investigate the mechanism behind its antiplatelet activity. PBME effects on agonist-induced platelet aggregation, granule secretion, [Ca2+]i mobilization, αIIbβ3 activation, cyclic AMP release and mitogen-activated protein kinase (MAPK) phosphorylations were studied using rat platelets. PBME dose-dependently inhibited collagen, thrombin and ADP-induced platelet aggregation with an IC50 of 51.0 ± 2.4, 54.0 ± 2.1 and 53.0 ± 4.3 μg/mL, respectively. Likewise, thrombin-induced [Ca2+]i and collagen-activated ATP secretions were suppressed in PBME treated platelets. Aggregation and ATP secretion were also markedly attenuated by PBME alone or in combination with PP2 (Src inhibitor) and U-73122 (PLC inhibitor) in collagen-stimulated platelets. Besides, PBME treatment elevated basal cyclic AMP levels and inhibited collagen-induced integrin-αIIbβ3 activation. Moreover, PBME attenuated extracellular-signal-regulated protein kinase 2 (ERK2) and c-Jun N-terminal kinase 1 (JNK1) phosphorylations. Further PD98059 (ERK inhibitor) and SP60025 (JNK inhibitor) reduced collagen-induced platelet aggregation and ATP secretion. In conclusion, the observed PBME antiplatelet activity may be mediated by activation of cyclic AMP and inhibition of ERK2 and JNK1 phosphorylations. Finally, these data suggest that PBME may have therapeutic potential for the treatment of cardiovascular diseases that involve aberrant platelet function. Copyright © 2011 John Wiley & Sons, Ltd.
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- 2011
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16. Characteristics of a Producing Process of the Television Genre -over Program: Focused on the KBS 2TV <Sponge>
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Sang-Keun Kim
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Engineering ,Television studies ,Multimedia ,Process (engineering) ,business.industry ,media_common.quotation_subject ,ComputingMilieux_PERSONALCOMPUTING ,computer.software_genre ,Style (sociolinguistics) ,Television production ,Production (economics) ,Function (engineering) ,business ,computer ,media_common - Abstract
Nowadays, `fusion style` television programs are increasingly found in the production of television program. Originally such a trend has been developed with a purpose of changing tedious cultural program into entertaining style. Recently, however, it has also become as an alternative style of genre which is against from lasciviousness or lewdness of entertaining programs. This study is designed to analyse the characteristics of television production and theorize a producing process of the television genre-over program As a result of various aspects of research, it is found that recent producers who make genre-over program choose any kind of genre which is thought to be needed for their program, without any limitation in terms of methods or skills for specific genre. And with this change of concept for making programs, genre-over programs are newly defined as the entertaining programs, in which its entertaining function is widen and broaden, absorbing the informative function of cultural programs.
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- 2011
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17. Development of Planar Active Electronically Scanned Array(AESA) Radar Prototype for Airborne Fighter
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Dong-Yoon Kim, Sang-Keun Kim, Sang-Mi Chon, Hyung-Gi Na, and Min-Kil Chong
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Engineering ,business.industry ,Active electronically scanned array ,Beam steering ,Electrical engineering ,Distributed power ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,law.invention ,Planar ,Duty cycle ,law ,Antenna (radio) ,Radar ,business ,Beam (structure) - Abstract
This paper presents a design, fabrication and the test results of planar active electronically scanned array(AESA) radar prototype for airborne fighter applications using transmit/receive(T/R) module hybrid technology. LIG Nex1 developed a AESA radar prototype to obtain key technologies for airborne fighter`s radar. The AESA radar prototype consists of a radiating array, T/R modules, a RF manifold, distributed power supplies, beam controllers, compact receivers with ADC(Analog-to-Digital Converter), a liquid-cooling unit, and an appropriate structure. The AESA antenna has a 590 mm-diameter, active-element area capable of containing 536 T/R modules. Each module is located to provide a triangle grid with spacing among T/R modules. The array dissipates 1,554 watts, with a DC input of 2,310 watts when operated at the maximum transmit duty factor. The AESA radar prototype was tested on near-field chamber and the results become equal in expected beam pattern, providing the accurate and flexible control of antenna beam steering and beam shaping.
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- 2010
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18. A noble function of BAY 11-7082: Inhibition of platelet aggregation mediated by an elevated cAMP-induced VASP, and decreased ERK2/JNK1 phosphorylations
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Hyun-Jeong Cho, Whi Min Lee, Won Jun Oh, Hyun-Sub Lee, SM Kamruzzaman, Sang Keun Kim, Sung Dae Kim, Hwa-Jin Park, Mehari Endale, Man Hee Rhee, and Jae Youl Cho
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Blood Platelets ,Male ,medicine.medical_specialty ,IBMX ,Platelet Aggregation ,p38 mitogen-activated protein kinases ,Anti-Inflammatory Agents ,Intracellular Space ,Pharmacology ,Biology ,Rats, Sprague-Dawley ,Thromboxane A2 ,chemistry.chemical_compound ,Adenosine Triphosphate ,Internal medicine ,Nitriles ,Cyclic AMP ,medicine ,Animals ,Mitogen-Activated Protein Kinase 8 ,Platelet ,Sulfones ,Platelet activation ,Phosphorylation ,Protein kinase A ,Cyclic GMP ,Mitogen-Activated Protein Kinase 1 ,Forskolin ,Kinase ,Microfilament Proteins ,NF-kappa B ,Thrombin ,Phosphoproteins ,Rats ,P-Selectin ,Endocrinology ,Gene Expression Regulation ,chemistry ,Calcium ,Collagen ,Cell Adhesion Molecules - Abstract
Platelets, though anucleated, possess several transcription factors, including NF-kappaB, that exert non-genomic functions regulating platelet activation. Since platelets have not only been recognized as central players of homeostasis, but also participated in pathological conditions such as thrombosis, atherosclerosis, and inflammation, we examined rat platelet NF-kappaB expression and evaluated the effects of anti-inflammatory drug BAY 11-7082, an inhibitor of NF-kappaB activation, in platelet physiology. Western blotting revealed that rat platelets express NF-kappaB. BAY 11-7082, dose dependently, inhibited collagen- or thrombin-induced-platelet aggregation. ATP release, TXB(2) formation, P-selectin expression, and intercellular Ca(2+) concentration activated by collagen were reduced in BAY 11-7082-treated platelets. BAY 11-7082 elevated intracellular levels of cAMP, but not cGMP, and its co-incubation with cAMP-activating agent (forskolin) or its hydrolyzing enzyme inhibitor (3-isobutyl-1-methylxanthine, IBMX), synergistically inhibited collagen-induced-platelet aggregation. In addition, vasodilator-stimulated-phosphoprotein (VASP) phosphorylation was enhanced in BAY 11-7082-treated platelets, which was partially inhibited by a protein kinase A (PKA) inhibitor, H-89. Moreover, while p38 mitogen-activated protein kinase (MAPK) was not affected, BAY 11-7082 attenuated c-Jun N-terminal kinase 1 (JNK1) and extracellular-signal-regulated protein kinase 2 (ERK2) phosphorylations. In conclusion, BAY 11-7082 inhibits platelet activation, granule secretion, and aggregation, and that this effect is mediated by inhibition of JNK1 and ERK2 phosphorylations, and partially by stimulation of cAMP-dependent PKA VASP phosphorylation. The ability of BAY 11-7082 to inhibit platelet function might be relevant in cases involving aberrant platelet activation where the drug is considered as anti-atherothrombosis, and anti-inflammatory therapy.
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- 2010
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19. T/R Module Development for X-Band Active Phased-Array Radar
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Seon-Joo Kim, Hyung-Gi Na, Sang-Mi Chon, Dong-Yoon Kim, Sang-Keun Kim, Min-Kil Chong, Seung-Hun Baik, and Chang-Soo Ahn
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Third-order intercept point ,Attenuator (electronics) ,Engineering ,Phased array ,business.industry ,X band ,Electrical engineering ,Noise figure ,law.invention ,law ,Electronic engineering ,Active Phased Array Radar ,Radar ,business ,Phase shift module - Abstract
This paper presents design and test results of X-Band Transmit/Receive(T/R) module for active phased-array radar. Active phased array radars typically require solid state T/R modules with high output power, low noise figure, high Third Order Intercept(TOI), and sufficient gain in both transmit and receive. The output power of the module is 9 watts over a wide bandwidth. The noise figure is as low as 2.8 dB. Phase and amplitude are controlled by the 6-bit phase shifter and 5-bit attenuator, respectively. Highly integrated T/R module is achieved by using LTCC(Low Temperature Co-fired Ceramic) multiple layer substrate. The module incorporates a compact digital interface, requires only three supply voltages.
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- 2009
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20. Design of 4-Bit TDL(True-Time Delay Line) for Elimination of Beam-Squint in Wide Band Phased-Array Antenna
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Su-Bum Kim, Se-Young Kim, Jin-Bong Sung, Sang-Keun Kim, Hyung-Gi Na, Min-Kil Chong, and Seung-Hun Baik
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Microstrip antenna ,Engineering ,Phased array ,business.industry ,Bandwidth (signal processing) ,Electronic engineering ,Wide band ,4-bit ,Noise figure ,business ,True time delay ,Microstrip - Abstract
In this paper, we have designed TDL(True-time Delay Line) for eliminating beam-squint occurring in active phased array antenna with large electrical size operated in wide bandwidth, and have tested its electrical performance. The proposed TDL device is composed of 4-bit microstrip delay line structure and MMIC amplifier for compensation of the delay-line loss. The measured results of gain and phase versus delay state satisfy the electrical requirements, also P1dB output power and noise figure meet the requirement. To verify the performance of fabricated TDL, we have simulated the beam patterns of wide-band active phased array antenna using the measured results and have certified the beam pattern compensation performance. As a result of simulated beam pattern compensation with respect to the 675.8 mm size antenna which is operated in X-band, 800 MHz bandwidth, we have reduced the beam squint error of with . So this TDL module is able to be applied to active phase array antenna system.
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- 2009
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21. A Design and Fabrication of the X-Band Transmit/Receive Module for Active Phased Array SAR Antennas
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Dong-Woo Yi, Hyung-Gi Na, Sang-Keun Kim, Seung-Hun Baik, Min-Kil Chong, and Jong-Hwan Lee
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Synthetic aperture radar ,Attenuator (electronics) ,Engineering ,Optics ,business.industry ,Phased array ,Bandwidth (signal processing) ,Electrical engineering ,X band ,Power dividers and directional couplers ,business ,Noise figure ,Phase shift module - Abstract
In this paper, a X-Band T/R-module for SAR(Synthetic Aperture Radar) systems based on active phased array antennas is designed and fabricated. The T/R modules have a and width of more than 800 MHz centered at X-Band and support dual, switched polarizations. The output power of the module is 7 watts over a wide bandwidth. The noise figure is as low as 3.9 dB. Phase and amplitude are controlled by a 6-bit phase shifter and a 6-bit digital attenuator, respectively. Further the fabricated T/R module has est and calibration port with directional coupler and power divider. Highly integrated T/R module is achieved by using LTCC(Low Temperature Co-fired Ceramic) multiple layer substrate. RMS gain error is less than 0.8 dB max. in Rx mode, and RMS phase error is less than max. in Rx/Tx phase under all operating frequency band, or the T/R module meet the required electrical performance m test. This structure an be applied to active phase array SAR Antennas.
- Published
- 2009
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22. Vincent van Gogh, the Missionary
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Sang Keun Kim
- Subjects
media_common.quotation_subject ,Art history ,Performance art ,Art ,media_common - Published
- 2009
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23. Evaluation of antioxidant, antinociceptive, and anti-inflammatory activities of ethanol extracts from Aloe saponaria Haw
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Man Hee Rhee, Sang Keun Kim, Eun Ah Yoo, Wongi Min, Hwa Jin Park, Whi Min Lee, Jae Youl Cho, and Sung Dae Kim
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Pharmacology ,Antioxidant ,biology ,medicine.drug_class ,DPPH ,medicine.medical_treatment ,Pharmacognosy ,biology.organism_classification ,Anti-inflammatory ,Nitric oxide ,Biphenyl compound ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Randall–Selitto test ,medicine ,Saponaria - Abstract
Aloe species are traditionally prescribed for hypertension, burning, and rheumatoid arthritis. To elucidate the mechanism of the antihypertensive and anti-inflammatory activities of this herb, the ethanol fraction from A. saponaria Haw. was evaluated for antioxidative activity using xanthine-xanthine oxidase (XO) assay, 2,2-Diphenyl-lpicrylhydrazyl radical (DPPH) assay, lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cell, and antinociceptive activity using a tail-flick assay and hind paw pressure assay in cisplatin-treated hyperalgesic rats. The ethanol fraction displayed potent antioxidative activities in XO assay. In addition, ethanol fractions showed potent scavenging effects in DPPH assay. We next examined whether ethanol fractions showed anti-inflammatory activities. Ethanol fractions significantly suppressed NO production from LPS-activated RAW264.7 cells. As expected, ethanol fractions dose-dependently inhibited the messenger RNA expression of inducible NO synthase (iNOS). Moreover, ethanol fractions potently suppressed the expression of cycloxygenase (COX)-2 and granulocyte-macrophage colony-stimulating factor (GM-CSF), which are stimulated by LPS in RAW264.7 cells. In addition, ethanol fractions significantly blocked cisplatin-induced hyperalgesia using tail-flick assay and hind paw pressure test in rats. Taken altogether, ethanol extracts of aloe may be useful as a functional food or as a drug against reactive oxygen species (ROS) mediated diseases.
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- 2008
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24. Vitrification of Canine Oocytes
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Yasuyuki Abe, Sang-Keun Kim, Dong-Soo Lee, and Hiroshi Suzuki
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Sucrose ,Chromatography ,Significant difference ,Cell Biology ,Anatomy ,Liquid nitrogen ,Oocyte ,Cryopreservation ,chemistry.chemical_compound ,medicine.anatomical_structure ,Reproductive Medicine ,chemistry ,DAP213 solution ,medicine ,Vitrification ,Ethylene glycol - Abstract
The objective of the present study was to compare the vitrification method for cryopreservation of canine oocytes. Canine cumulus-oocyte complexes (COCs) were collected from ovaries, and were vitrified by ethylene glycol based (E30S) or DMSO based (DAP213) methods. In the E30S method, COCs were exposed to the vitrification solution, composed of 30% ethylene glycol and 0.5 M sucrose, step-wise transferred onto a cryotop holder, then plunged directly into liquid nitrogen. In the DAP213 method, COCs were exposed to 1 M DMSO and DAP213 solution in a cryotube, and thereafter plunged directly into liquid nitrogen. Although vitrified-warmed COCs in the E30S method showed fewer morphological abnormalities, and higher viability than those in the DAP213 method, there was no significant difference in between. These results indicate that either method of vitrification is available and statistically comparable for cryopreservation of canine oocytes.
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- 2008
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25. Peroxiredoxin I Is an Indicator of Microglia Activation and Protects against Hydrogen Peroxide-Mediated Microglial Death
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Sangho Lee, Jin Man Kim, Hwang Lee, Hu Nan Sun, Mei‑Hua Jin, Dong-Seok Lee, Chang Nam Hwang, Sun Uk Kim, Dae Yeul Yu, Ying Hao Han, and Sang Keun Kim
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Lipopolysaccharides ,Male ,Programmed cell death ,Cell type ,Lipopolysaccharide ,Cell Survival ,p38 mitogen-activated protein kinases ,Blotting, Western ,Pharmaceutical Science ,Biology ,medicine.disease_cause ,Mice ,chemistry.chemical_compound ,Downregulation and upregulation ,medicine ,Animals ,Inflammation ,Pharmacology ,Mice, Inbred ICR ,Cell Death ,Microglia ,Hydrogen Peroxide ,Peroxiredoxins ,General Medicine ,Up-Regulation ,Cell biology ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Peroxiredoxin ,Oxidative stress - Abstract
Imbalance between oxidative stress and antioxidative defence system is generally known as one of mechanisms causing an oxidative stress-medieated neuropathogenesis. Peroxiredoxins (Prxs), a family of antioxidative enzymes neutralizing cellular hydroperoxides, was characterized recently, but their distributions and roles have not been resolved clearly or controversial in the central nervous system, Therefore, the present study was carried out to determine the specific cell types that express Prx I in the mouse brain and primary neural cells, and to examine its antioxidative role in the preferential cell types. Immunohistochemical reactivity for Prx I was detected dominantly in oligodendrocytes and rarely in microglia, whereas strong and specific immunoreactivity for Prx I was observed exclusively in microglia of primary neural cell culture. Further evidences for Prx I specificity were its relatively high expression in BV-2 microglial cells and its upregulated expression in microglia after lipopolysaccharide (LPS) stimulation. These results imply that Prx I can be used as an indicator of microglial activation. Inhibition of p38 MAPK ablated LPS-mediated Prx I upregulation and sensitized the microglia to H(2)O(2)-mediated cell death. These findings indicate that Prx I function as a scavenger for H(2)O(2) generated during microglial activation. The results of this study will help in unraveling the neuropathologic roles of the six Prx isoforms in neural function.
- Published
- 2008
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26. Permeable reactive barrier using atomized slag material for treatment of contaminants from landfills
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Jun Yu, Sang Keun Kim, Yong Soo Lee, and Ha Ik Chung
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Materials science ,business.industry ,Environmental remediation ,Metallurgy ,Slag ,Contamination ,Steelmaking ,Adsorption ,Permeable reactive barrier ,visual_art ,visual_art.visual_art_medium ,General Earth and Planetary Sciences ,Leachate ,business ,General Environmental Science ,Reactive material - Abstract
This paper presented a permeable reactive barrier using atomized slag material for the treatment of landfill leachate and contaminated ground water. This study investigated the feasibility of using atomized slag and modified by products from iron and steel making industries as new reactive material for leachate treatment. Batch and column tests, and field pilot tests were performed as model systems to explore the effect of atomized slag as an alternative reactive material. From the evaluation of various atomized slag based PRB systems, a combination of an atomized slag and sand system was found to have a substantial reaction capacity for leachate and organics, thus it has the potential to be used in the permeable reactive barriers for a subsurface remediation. The test results showed that the adsorption capacity is high in the order of pH 7>pH 5>pH 9, the heavy metal removal rate is high in the order of Cd>Pb>Cr>Cu, and organic removal rate is high in the order of T-P>COD>T-N.
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- 2007
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27. Surfactin C inhibits platelet aggregation
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Kyoung Youl Lee, Sun Kyu Park, Seung-Chun Park, Hyo In Yun, Jong Hwan Lim, Man Hee Rhee, Sang Keun Kim, Hwa Jin Park, Jae Youl Cho, and Sung Dae Kim
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Agonist ,Platelet Aggregation ,medicine.drug_class ,medicine.medical_treatment ,Pharmaceutical Science ,Bacillus subtilis ,Peptides, Cyclic ,Phospholipases A ,Lipopeptides ,Thrombin ,medicine ,Animals ,Platelet ,Receptor ,Pharmacology ,Protease ,Dose-Response Relationship, Drug ,biology ,U937 cell ,Chemistry ,Ligand (biochemistry) ,biology.organism_classification ,Rats ,Biochemistry ,Calcium ,lipids (amino acids, peptides, and proteins) ,Collagen ,Platelet Aggregation Inhibitors ,medicine.drug - Abstract
This study was designed to investigate the effect of surfactin C, which is derived from Bacillus subtilis, on platelet aggregation and homotypic leucocyte aggregation. Surfactin C strongly and dose-dependently inhibited platelet aggregation, which was stimulated both by thrombin (0.1 U mL−1), a potent agonist that activates the G protein-coupled protease receptor, and by collagen (5 μg mL−1), a potent ligand that activates αIIbβ3 with IC50 values (concentration inhibiting platelet aggregation by 50%) of 10.9 and 17.0 μM, respectively. Moreover, surfactin C significantly suppressed the intracellular Ca2+ mobilization in thrombin-activated platelets. Surfactin C, however, did not affect various integrin-mediated U937 cell aggregation, implying that the anti-platelet activity of surfactin C was not due to its detergent effect but by its action on the downstream signalling pathway. Therefore, the results suggest that surfactin C may have a beneficial therapeutic effect on aberrant platelet aggregation-mediated cardiovascular diseases.
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- 2006
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28. Radical scavenging and anti-inflammatory activity of extracts from Opuntia humifusa Raf
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Choong-Hwan Lee, Jae-Chan Song, Sang-Keun Kim, Seung-Chun Park, Hui-Min Lee, Hye-Jin Sung, Tae-Wan Kim, Yong-Beom Song, Man Hee Rhee, Kil-Soo Kim, Jae Youl Cho, Hwa-Jin Park, and Eun-Sook Yoo
- Subjects
Lipopolysaccharides ,Xanthine Oxidase ,Cell Survival ,medicine.drug_class ,DPPH ,Ethyl acetate ,Nitric Oxide Synthase Type II ,Pharmaceutical Science ,Nitric Oxide ,Plant Roots ,Anti-inflammatory ,Cell Line ,Nitric oxide ,chemistry.chemical_compound ,Picrates ,medicine ,RNA, Messenger ,Xanthine oxidase ,Pharmacology ,Chloroform ,Interleukin-6 ,Plant Extracts ,Anti-Inflammatory Agents, Non-Steroidal ,Biphenyl Compounds ,Opuntia ,Free Radical Scavengers ,Plant Leaves ,Solvent ,Hydrazines ,chemistry ,Biochemistry ,Fruit ,Quercetin ,Interleukin-1 - Abstract
Opuntia humifusa Raf. (O. humifusa Raf.) is a member of the Cactaceae family. To determine the antioxidative and anti-inflammatory effects of this herb, various solvent fractions (methanol, hexane, chloroform, ethyl acetate, butanol, and water) prepared from the leaves of cacti were tested using DPPH (2,2-diphenyl-l-picrylhydrazyl radical) and xanthine oxidase assays, and nitric oxide (NO)-producing macrophage cells. We found that O. humifusa Raf. displayed potent antioxidative and anti-inflammatory activity. Thus, all solvent fractions, except for the water layer, showed potent scavenging effects. The scavenging effect of the ethyl acetate fraction was higher than that of the other fractions, with IC50 values of 3.6 and 48.2 μg mL−1. According to activity-guided fractionation, one of the active radical scavenging principles in the ethyl acetate fraction was found to be quercetin. In contrast, only two fractions (chloroform and ethyl acetate) significantly suppressed nitric oxide production from the lipopolysaccharide (LPS)-activated RAW264.7 cells. In addition, chloroform and ethyl acetate fractions significantly blocked the expression of inducible nitric oxide synthetase (iNOS) and interleukin-6 (IL-6) from the RAW264.7 cells stimulated by LPS. Moreover, ethyl acetate fractions significantly blocked the expression of IL-1β from the RAW264.7 cells stimulated by LPS. Therefore, the results suggested that O. humifusa Raf. may modulate radical-induced toxicity via both direct scavenging activity and the inhibition of reactive species generation, and the modulation of the expression of inflammatory cytokines. Finally, O. humifusa Raf. may be useful as a functional food or drug against reactive species-mediated disease.
- Published
- 2006
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29. Treatment of landfill leachates: ammonia removal via nitrification and denitrification and further COD reduction via Fenton's treatment followed by activated sludge
- Author
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Jae-Ho Bae, Sang-Keun Kim, and Hyun-Sik Chang
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Denitrification ,Environmental Engineering ,Inorganic chemistry ,Pulp and paper industry ,chemistry.chemical_compound ,Activated sludge ,chemistry ,Nitrate ,Anaerobic filter ,Nitrification ,Leachate ,Nitrite ,Effluent ,Water Science and Technology - Abstract
Leachates from a municipal solid waste landfill were treated by anaerobic filter (AF) and two-stage activated sludge (AS) for the removal of ammonia. Nitrification in the first stage AS was efficient, but was unstable with temporary accumulations of nitrite by free ammonia toxicity. With the second stage AS, complete nitrification of ammonia and nitrite was achieved. Denitrification via nitrite occurred with the first stage AS effluent recycle, and the resulting AF effluent NOx concentration was kept lower compared to the case in which denitrification via nitrate only occurred with the second stage AS effluent recycle. This might happen because of low COD/N ratio of the raw leachate, and suggests that denitrification via nitrite may be a valuable option. In AF, denitrifiers out-compete methanogens for COD. Ammonia-removed leachate was treated with Fenton's reagents followed by post-AS for further COD removal. Fenton's treatment reduced COD by 63%. Up to 74 mg/L of COD was removed when 100 mg/L of sucrose was added to post-AS. With the above treatment system, 1400∼1800 mg/L of NH4-N was completely removed, leaving 200 mg/L of nitrate nitrogen. Also, 4000∼7000 mg/L of COD in the raw leachate was reduced to 150∼200 mg/L.
- Published
- 1997
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30. A study on the optimum structural design of surface effect ships
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Seung Il Seo, Sang Keun Kim, and C.D. Jang
- Subjects
Optimal design ,Engineering ,business.industry ,Mechanical Engineering ,Frame (networking) ,Minimum weight ,Ocean Engineering ,Structural engineering ,Naval architecture ,Mechanics of Materials ,Hull ,Girder ,General Materials Science ,Reduction (mathematics) ,business ,Global optimization - Abstract
In this study, a method to design hull structures of surface effect ships with minimum weight is proposed, and computer programs following the method are also developed. The proposed method considers structural characteristics inherent to surface effect ships by rational structural analyses, but adopts a simplified analysis model to enhance computing efficiency during optimization process. The proposed method uses design loads and strength criteria suggested by the class rules of DnV, but the interaction effect of longitudinal girders and transverse web frames are considered by the simple and accurate grillage analysis method. As design of the midship section is accomplished through optimum design of partial structures such as stiffened plates and complex girders and frame structures, global optimization of all design variables is avoided and computing efficiency is raised. And also, the proposed method contains the simple torsional strength and analysis routine and optimization process of transverse bulkheads against pitch connection moment. Applying the proposed method to ship design, 20% reduction of hull weight was confirmed, and it can be shown that hull weight varies with the change of frame space and there exists optimum frame space.
- Published
- 1996
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31. Hepatitis B virus X protein regulates hepatic glucose homeostasis via activation of inducible nitric oxide synthase
- Author
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Nam-Soon Kim, Dae-Yeul Yu, Jin Man Kim, In-Sung Song, Chul-Ho Lee, Cheol Soo Choi, Sun-Uk Kim, Hye-Jun Shin, Do-Sim Park, Dong-Seok Lee, Su Sung Kim, Sang-Keun Kim, Yo Na Kim, Ying-Hao Han, Young-Bum Kim, Hyung-Bae Moon, Young-Ho Park, Dae-Ghon Kim, Dae Ho Lee, and Minhye Kim
- Subjects
viruses ,Jun N-terminal Kinase (JNK) ,Nitric Oxide Synthase Type II ,Biochemistry ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Homeostasis ,Viral Regulatory and Accessory Proteins ,Regulation of gene expression ,Mice, Knockout ,0303 health sciences ,biology ,Metabolic disorder ,Molecular Bases of Disease ,Hep G2 Cells ,3. Good health ,Nitric oxide synthase ,HBx ,Liver ,030220 oncology & carcinogenesis ,Signal Transduction ,medicine.medical_specialty ,Hepatitis B virus ,Carbohydrate metabolism ,Nitric Oxide ,Gene Expression Regulation, Enzymologic ,Nitric oxide ,03 medical and health sciences ,Insulin resistance ,Hepatitis Virus ,Metabolic Diseases ,Internal medicine ,medicine ,Animals ,Humans ,Mitogen-Activated Protein Kinase 8 ,Molecular Biology ,030304 developmental biology ,Endothelium-Dependent Relaxing Factors ,Gluconeogenesis ,Cell Biology ,medicine.disease ,digestive system diseases ,Endocrinology ,Glucose ,chemistry ,Hyperglycemia ,biology.protein ,Trans-Activators ,Nitric Oxide Synthase - Abstract
Dysregulation of liver functions leads to insulin resistance causing type 2 diabetes mellitus and is often found in chronic liver diseases. However, the mechanisms of hepatic dysfunction leading to hepatic metabolic disorder are still poorly understood in chronic liver diseases. The current work investigated the role of hepatitis B virus X protein (HBx) in regulating glucose metabolism. We studied HBx-overexpressing (HBxTg) mice and HBxTg mice lacking inducible nitric oxide synthase (iNOS). Here we show that gene expressions of the key gluconeogenic enzymes were significantly increased in HepG2 cells expressing HBx (HepG2-HBx) and in non-tumor liver tissues of hepatitis B virus patients with high levels of HBx expression. In the liver of HBxTg mice, the expressions of gluconeogenic genes were also elevated, leading to hyperglycemia by increasing hepatic glucose production. However, this effect was insufficient to cause systemic insulin resistance. Importantly, the actions of HBx on hepatic glucose metabolism are thought to be mediated via iNOS signaling, as evidenced by the fact that deficiency of iNOS restored HBx-induced hyperglycemia by suppressing the gene expression of gluconeogenic enzymes. Treatment of HepG2-HBx cells with nitric oxide (NO) caused a significant increase in the expression of gluconeogenic genes, but JNK1 inhibition was completely normalized. Furthermore, hyperactivation of JNK1 in the liver of HBxTg mice was also suppressed in the absence of iNOS, indicating the critical role for JNK in the mutual regulation of HBx- and iNOS-mediated glucose metabolism. These findings establish a novel mechanism of HBx-driven hepatic metabolic disorder that is modulated by iNOS-mediated activation of JNK.
- Published
- 2011
32. Antiplatelet activity of Phellinus baummii methanol extract is mediated by cyclic AMP elevation and inhibition of collagen-activated integrin-α(IIb) β₃ and MAP kinase
- Author
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S M, Kamruzzaman, Mehari, Endale, Won-Jun, Oh, Seung-Chun, Park, Tae-Hwan, Kim, In-Kyoung, Lee, Jae Youl, Cho, Hwa-Jin, Park, Sang Keun, Kim, Bong-Sik, Yun, and Man Hee, Rhee
- Subjects
Blood Platelets ,Male ,Mitogen-Activated Protein Kinase 1 ,Biological Products ,Platelet Aggregation ,Basidiomycota ,Thrombin ,Platelet Glycoprotein GPIIb-IIIa Complex ,Platelet Activation ,Rats ,Rats, Sprague-Dawley ,Cyclic AMP ,Animals ,Mitogen-Activated Protein Kinase 8 ,Collagen ,Mitogen-Activated Protein Kinases ,Phosphorylation ,Agaricales ,Platelet Aggregation Inhibitors - Abstract
Phellinus baumii is a mushroom that has been used as folk medicine against various diseases and is reported to have antidiabetic, anticancer, antioxidant, antiinflammatory and antihypertensive activities. However, information on the effects of P. baumii extract in platelet function is limited. Therefore, the aim of this study was to examine the impact of a P. baumii methanol extract (PBME) on platelet activation and to investigate the mechanism behind its antiplatelet activity. PBME effects on agonist-induced platelet aggregation, granule secretion, [Ca²⁺](i) mobilization, α(IIb) β₃ activation, cyclic AMP release and mitogen-activated protein kinase (MAPK) phosphorylations were studied using rat platelets. PBME dose-dependently inhibited collagen, thrombin and ADP-induced platelet aggregation with an IC₅₀ of 51.0 ± 2.4, 54.0 ± 2.1 and 53.0 ± 4.3 μg/mL, respectively. Likewise, thrombin-induced [Ca²⁺](i) and collagen-activated ATP secretions were suppressed in PBME treated platelets. Aggregation and ATP secretion were also markedly attenuated by PBME alone or in combination with PP2 (Src inhibitor) and U-73122 (PLC inhibitor) in collagen-stimulated platelets. Besides, PBME treatment elevated basal cyclic AMP levels and inhibited collagen-induced integrin-α(IIb) β₃ activation. Moreover, PBME attenuated extracellular-signal-regulated protein kinase 2 (ERK2) and c-Jun N-terminal kinase 1 (JNK1) phosphorylations. Further PD98059 (ERK inhibitor) and SP60025 (JNK inhibitor) reduced collagen-induced platelet aggregation and ATP secretion. In conclusion, the observed PBME antiplatelet activity may be mediated by activation of cyclic AMP and inhibition of ERK2 and JNK1 phosphorylations. Finally, these data suggest that PBME may have therapeutic potential for the treatment of cardiovascular diseases that involve aberrant platelet function.
- Published
- 2010
33. Microglial peroxiredoxin V acts as an inducible anti-inflammatory antioxidant through cooperation with redox signaling cascades
- Author
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Hu-Nan, Sun, Sun-Uk, Kim, Song Mei, Huang, Jin-Man, Kim, Young-Ho, Park, Seok-Ho, Kim, Hee-Young, Yang, Kyoung-Jin, Chung, Tae-Hoon, Lee, Hoon Sung, Choi, Ju Sik, Min, Moon-Ki, Park, Sang-Keun, Kim, Sang-Rae, Lee, Kyu-Tae, Chang, Sang-Ho, Lee, Dae-Yeul, Yu, and Dong-Seok, Lee
- Subjects
Lipopolysaccharides ,Male ,Mice, Inbred ICR ,JNK Mitogen-Activated Protein Kinases ,NADPH Oxidases ,Nitric Oxide Synthase Type II ,Peroxiredoxins ,Nitric Oxide ,Reactive Nitrogen Species ,Up-Regulation ,Mice ,Gene Knockdown Techniques ,Mutation ,Animals ,Microglia ,Reactive Oxygen Species ,Oxidation-Reduction ,Cells, Cultured ,Signal Transduction - Abstract
Reactive oxygen species (ROS) actively participate in microglia-mediated pathogenesis as pro-inflammatory molecules. However, little is known about the involvement of specific antioxidants in maintaining the microglial oxidative balance. We demonstrate that microglial peroxiredoxin (Prx) 5 expression is up-regulated by lipopolysaccharide (LPS) through activation of the ROS-sensitive signaling pathway and is involved in attenuation of both microglial activation and nitric oxide (NO) generation. Unlike in stimulation of oxidative insults with paraquat and hydrogen peroxide, Prx V expression is highly sensitive to LPS-stimulation in microglia. Reduction of ROS level by treatment with either NADPH oxidase inhibitor or antioxidant ablates LPS-mediated Prx V up-regulation in BV-2 microglial cells and is closely associated with the activation of the c-jun N-terminal kinase (JNK) signaling pathway. This suggests the involvement of ROS/JNK signaling in LPS-mediated Prx V induction. Furthermore, NO induces Prx V up-regulation that is ablated by the addition of inducible nitric oxide synthase inhibitor or deleted mutation of inducible nitric oxide synthase in LPS-stimulated microglia. Therefore, these results suggest that Prx V is induced by cooperative action among the ROS, RNS, and JNK signaling cascades. Interestingly, knockdown of Prx V expression causes the acceleration of microglia activation, including augmented ROS generation and JNK-dependent NO production. In summary, we demonstrate that Prx V plays a key role in the microglial activation process through modulation of the balance between ROS/NO generation and the corresponding JNK cascade activation.
- Published
- 2010
34. Microglial peroxiredoxin V acts as an inducible anti-inflammatory antioxidant through cooperation with redox signaling cascades
- Author
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Ju Sik Min, Sang-Rae Lee, Song Mei Huang, Dae Yeul Yu, Moon Ki Park, Dong-Seok Lee, Tae-Hoon Lee, Jin Man Kim, Kyoung-Jin Chung, Young-Ho Park, Sangho Lee, Kyu Tae Chang, Hu Nan Sun, Sun Uk Kim, Hee-Young Yang, Hoon Sung Choi, Sang Keun Kim, and Seok Ho Kim
- Subjects
NADPH oxidase ,Biology ,Biochemistry ,Molecular biology ,Nitric oxide ,Nitric oxide synthase ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,chemistry ,Mitogen-activated protein kinase ,biology.protein ,JNK cascade ,Signal transduction ,Peroxiredoxin ,Reactive nitrogen species - Abstract
Reactive oxygen species (ROS) actively participate in microglia-mediated pathogenesis as pro-inflammatory molecules. However, little is known about the involvement of specific antioxidants in maintaining the microglial oxidative balance. We demonstrate that microglial peroxiredoxin (Prx) 5 expression is up-regulated by lipopolysaccharide (LPS) through activation of the ROS-sensitive signaling pathway and is involved in attenuation of both microglial activation and nitric oxide (NO) generation. Unlike in stimulation of oxidative insults with paraquat and hydrogen peroxide, Prx V expression is highly sensitive to LPS-stimulation in microglia. Reduction of ROS level by treatment with either NADPH oxidase inhibitor or antioxidant ablates LPS-mediated Prx V up-regulation in BV-2 microglial cells and is closely associated with the activation of the c-jun N-terminal kinase (JNK) signaling pathway. This suggests the involvement of ROS/JNK signaling in LPS-mediated Prx V induction. Furthermore, NO induces Prx V up-regulation that is ablated by the addition of inducible nitric oxide synthase inhibitor or deleted mutation of inducible nitric oxide synthase in LPS-stimulated microglia. Therefore, these results suggest that Prx V is induced by cooperative action among the ROS, RNS, and JNK signaling cascades. Interestingly, knockdown of Prx V expression causes the acceleration of microglia activation, including augmented ROS generation and JNK-dependent NO production. In summary, we demonstrate that Prx V plays a key role in the microglial activation process through modulation of the balance between ROS/NO generation and the corresponding JNK cascade activation.
- Published
- 2010
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35. Automated control of blood glucose in the OR and surgical ICU
- Author
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Bo-Kyung Yoon, Sang-Keun Kim, Tsung-Jui Tsai, Joseph I. Wang, Jason J. Hsu, Amy Lee, Daniel Y. Li, Alex Liu, Stephanie Huang, and Charlotte H. Chen
- Subjects
Blood Glucose ,medicine.medical_specialty ,Operating Rooms ,Automatic control ,medicine.medical_treatment ,Biomedical Engineering ,Fuzzy logic control ,Fuzzy logic ,Automation ,Insulin Infusion Systems ,Fuzzy Logic ,Control theory ,medicine ,Humans ,Hypoglycemic Agents ,Insulin ,Intensive care medicine ,Glycemic ,Monitoring, Physiologic ,business.industry ,Fuzzy control system ,Decision Support Systems, Clinical ,Automated control ,Intensive Care Units ,Hyperglycemia ,Emergency medicine ,business ,Blood Chemical Analysis - Abstract
A device which integrates existing intravenous continuous glucose monitors and infusion pumps into a central hub for automated intravenous intensive insulin therapy, targeting non-diabetic critically-ill patients is presented. Additionally, a fuzzy logic based controller that is capable of automatically making closed-loop decisions to achieve tight glycemic control between a euglycemic range of 90 to 120 mg/dl is presented. Initial bench top testing shows a significant improvement in glycemic control with fuzzy logic control when compared to manual infusion protocols currently used in hospitals; future animal testing will be performed to verify these results in vivo.
- Published
- 2009
36. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent activation of phosphoinositide 3-kinase and p38 mitogen-activated protein kinase signal pathways is required for lipopolysaccharide-induced microglial phagocytosis
- Author
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Dong-Seok Lee, Hu-Nan Sun, Sang-Keun Kim, Dae-Yeul Yu, Mi-Sook Lee, Jin-Man Kim, Sun-Uk Kim, and Mijung Yim
- Subjects
MAPK/ERK pathway ,Lipopolysaccharides ,Phagocytosis ,Blotting, Western ,Pharmaceutical Science ,p38 Mitogen-Activated Protein Kinases ,Cell Line ,chemistry.chemical_compound ,Phosphatidylinositol 3-Kinases ,Humans ,Protein kinase A ,Pharmacology ,Inflammation ,NADPH oxidase ,Phosphoinositide 3-kinase ,biology ,Kinase ,NADPH Oxidases ,General Medicine ,Flow Cytometry ,Cell biology ,Enzyme Activation ,Oxidative Stress ,chemistry ,Biochemistry ,Microscopy, Fluorescence ,biology.protein ,Microglia ,Cell activation ,Reactive Oxygen Species ,Nicotinamide adenine dinucleotide phosphate ,Signal Transduction - Abstract
The importance of microglial reactive oxygen species (ROS) signaling in neuroinflammatory processes has been well demonstrated; however, relatively little is known regarding the related mechanisms underlying these processes. Here, we show that ROS-dependent signal pathways that govern microglial phagocytosis are highly dependent upon nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) activation. Specifically, phagocytosis was greatly reduced by both antioxidant and Nox inhibitor treatments in lipopolysaccharide (LPS)-stimulated BV-2 microglia. Additionally, there was a marked reduction in intracellular ROS content. These results suggest that Nox is the main ROS source for LPS-induced microglial phagocytosis. More decisive evidence for the involvement of ROS in phagocytosis was obtained from an examination of phosphatidyl inositol 3-kinase (PI3-K) and p38 mitogen-activated protein kinase (MAPK) signal pathway activation under reduced ROS levels. These two kinases were activated by LPS treatment and inhibited by ROS neutralization and Nox inhibition. We conclude that microglial phagocytosis requires ROS-dependent PI3-K and p38 MAPK activation and that Nox-derived ROS functions as an upstream regulator of both PI3-K and p38 MAPK. These findings will provide a fundamental basis for a therapeutic modality in inflammation-mediated neurodiseases.
- Published
- 2008
37. Evaluation of antioxidant, antinociceptive, and anti-inflammatory activities of ethanol extracts from Aloe saponaria Haw
- Author
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Eun Ah, Yoo, Sung Dae, Kim, Whi Min, Lee, Hwa Jin, Park, Sang Keun, Kim, Jae Youl, Cho, Wongi, Min, and Man Hee, Rhee
- Subjects
Analgesics ,Xanthine Oxidase ,Ethanol ,Plant Extracts ,Reverse Transcriptase Polymerase Chain Reaction ,Biphenyl Compounds ,Anti-Inflammatory Agents ,Drug Evaluation, Preclinical ,Granulocyte-Macrophage Colony-Stimulating Factor ,Nitric Oxide Synthase Type II ,Antioxidants ,Cell Line ,Rats ,Mice ,Picrates ,Cyclooxygenase 2 ,Animals ,Aloe ,Cisplatin - Abstract
Aloe species are traditionally prescribed for hypertension, burning, and rheumatoid arthritis. To elucidate the mechanism of the antihypertensive and anti-inflammatory activities of this herb, the ethanol fraction from A. saponaria Haw. was evaluated for antioxidative activity using xanthine-xanthine oxidase (XO) assay, 2,2-Diphenyl-lpicrylhydrazyl radical (DPPH) assay, lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cell, and antinociceptive activity using a tail-flick assay and hind paw pressure assay in cisplatin-treated hyperalgesic rats. The ethanol fraction displayed potent antioxidative activities in XO assay. In addition, ethanol fractions showed potent scavenging effects in DPPH assay. We next examined whether ethanol fractions showed anti-inflammatory activities. Ethanol fractions significantly suppressed NO production from LPS-activated RAW264.7 cells. As expected, ethanol fractions dose-dependently inhibited the messenger RNA expression of inducible NO synthase (iNOS). Moreover, ethanol fractions potently suppressed the expression of cycloxygenase (COX)-2 and granulocyte-macrophage colony-stimulating factor (GM-CSF), which are stimulated by LPS in RAW264.7 cells. In addition, ethanol fractions significantly blocked cisplatin-induced hyperalgesia using tail-flick assay and hind paw pressure test in rats. Taken altogether, ethanol extracts of aloe may be useful as a functional food or as a drug against reactive oxygen species (ROS) mediated diseases.
- Published
- 2008
38. Efficacy of Prolonged Tenofovir Monotherapy for Partial Virologic Response to Tenofovir in Treatment-Naïve Chronic Hepatitis B Patients
- Author
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G.Y. Kim, Sang-Keun Kim, Mi-Kyung Kim, S.A. Baek, Byung Seok Kim, Jeong Eun Song, Chang Hyeong Lee, and Seok Min Kang
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Therapy naive ,medicine.medical_specialty ,Hepatology ,Tenofovir ,Chronic hepatitis ,business.industry ,Virologic response ,Internal medicine ,medicine ,business ,Gastroenterology ,medicine.drug - Published
- 2016
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39. Exploratory ring-opening polymerization: Ring-opening polymerization of vinylketene cyclic acetal
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Iwhan Cho and Sang-Keun Kim
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chemistry.chemical_compound ,Reaction mechanism ,chemistry ,Acetal ,Polymer chemistry ,Radical polymerization ,General Engineering ,General Materials Science ,Solution polymerization ,Ring-opening polymerization - Abstract
La polymerisation radicalaire dans le benzene du 4-phenyl-2-propenylene-1,3-dioxolane donne le polyester [CH 2 -CH=CH-COO-CH 2 -CH(Ph)] n . Discussion du mecanisme.
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- 1990
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40. In vitro anti-oxidative and anti-inflammatory effects of solvent-extracted fractions from Suaeda asparagoides
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Jong Min, Park, Sung Dae, Kim, Whi Min, Lee, Jae Youl, Cho, Hwa Jin, Park, Tae Wan, Kim, Nong-Hoon, Choe, Sang Keun, Kim, and Man Hee, Rhee
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Lipopolysaccharides ,Xanthine Oxidase ,Plant Extracts ,Reverse Transcriptase Polymerase Chain Reaction ,Macrophages ,Biphenyl Compounds ,Anti-Inflammatory Agents ,Nitric Oxide Synthase Type II ,Tetrazolium Salts ,Free Radical Scavengers ,Chenopodiaceae ,Nitric Oxide ,Antioxidants ,Cell Line ,Mice ,Thiazoles ,Phenols ,Picrates ,Solvents ,Animals ,Cytokines ,RNA, Messenger ,Chemokines ,Enzyme Inhibitors ,Cell Proliferation - Abstract
Suaeda asparagoides Miq. (Chenopodiaceae: S. asparagoides) is a salt-marsh plant that has long been prescribed in traditional Oriental medicine for the treatment of hypertension and hepatitis. In order to elucidate the pharmacological mechanisms of the herb, we conducted an examination of the anti-oxidative and anti-inflammatory properties of solvent-extracts of S. asparagoides. All of the solvent fractions showed potent anti-oxidative effects, as assessed using a radical generation assay system (xanthine oxidase assay) and an electron-donating activity system (DPPH [2,2-diphenyl-l-picrylhydrazyl radical] assay), with IC50 values ranging from 9 to 42 microg/ml. In agreement with this pattern, the total phenolic contents were widely distributed in the various solvent fractions, and ranged from 36.5 to 50.3 mg/g of dry weight. All of the solvent fractions significantly suppressed NO production in RAW264.7 cells induced by lipopolysaccharide (LPS, 0.1 microg/ml) and of the fractions, only the chloroform (CHC) fraction completely blocked the expression of inducible NO synthase (iNOS). Additionally, the hexane (HEX) and CHC fractions suppressed the mRNA expression of granulocyte/macrophage colony-stimulating factor (GM-CSF) and monocyte chemoattractant protein 1 (MCP-1), respectively, in the LPS-stimulated RAW264.7 cells. Therefore, these results suggest that the pharmacological action of S. asparagoides is due to its potent anti-oxidative effects and anti-inflammatory effects, and that therefore it can be applied to other diseases caused by oxidative stress and inflammation, such as cardiovascular diseases.
- Published
- 2007
41. The mechanism of anti-platelet activity of davallialactone: involvement of intracellular calcium ions, extracellular signal-regulated kinase 2 and p38 mitogen-activated protein kinase
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Man Hee Rhee, Seung-Chun Park, Jae Wook Oh, Bong-Sik Yun, Sang Keun Kim, Jae Youl Cho, Hwa Jin Park, Sung Dae Kim, Whi Min Lee, Yi Seong Kwak, and In-Kyoung Lee
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MAPK/ERK pathway ,Blood Platelets ,P2Y receptor ,Platelet Aggregation ,MAP Kinase Signaling System ,Biology ,p38 Mitogen-Activated Protein Kinases ,chemistry.chemical_compound ,Lactones ,Extracellular ,Animals ,Calcium Signaling ,Phosphorylation ,Protein kinase A ,Phosphotyrosine ,Pharmacology ,Mitogen-Activated Protein Kinase 1 ,Dose-Response Relationship, Drug ,Davallialactone ,Thrombin ,Tyrosine phosphorylation ,Rats ,Adenosine Diphosphate ,Biochemistry ,chemistry ,Collagen ,Intracellular ,Platelet Aggregation Inhibitors - Abstract
This study was designed to investigate the effect of davallialactone, which was isolated from the mushroom Inonotus xeranticus , on platelet aggregation induced by collagen, thrombin and ADP. We found that davallialactone dose-dependently inhibited platelet aggregation that was stimulated either by collagen (2.5 µg/ml), a potent ligand of integrin α2β1 and glycoprotein VI, or by thrombin (0.1U/ml), a potent agonist of the protease-activated receptors (PARs) PAR1 and PAR3. In addition, davallialactone inhibited platelet aggregation induced by ADP, an agonist of P2Y receptor. To understand the mechanism of anti-platelet activity, we determined whether davallialactone affected the downstream signaling in collagen-activated platelets. Using the fura-2/AM fluorometric assay, we found that davallialactone dose-dependently inhibited intracellular calcium concentration levels ([Ca 2+ ] i ). Moreover, davallialactone inhibited the phosphorylation of extracellular signal-regulated protein kinase (ERK)-2 and p38 mitogen-activated protein kinase (MAPK), in a dose-dependent manner. The tyrosine phosphorylation of 60 and 85kDa proteins, which were activated by collagen, were differentially inhibited by davallialactone. Taken together, these data suggest that davallialactone may have potential anti-platelet aggregation activity via suppression of intracellular downstream signaling pathways.
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- 2007
42. The expression patterns of RGS transcripts in platelets
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Hye Jin Sung, Tae-Wan Kim, Sun Kyu Park, Jae Youl Cho, Sung Dae Kim, Sang Keun Kim, Seung-Chun Park, and Man Hee Rhee
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G protein signalling ,Blood Platelets ,Reverse Transcriptase Polymerase Chain Reaction ,Gene Expression Profiling ,fungi ,Hematology ,General Medicine ,Biology ,Molecular biology ,Pathophysiology ,Rats ,Receptors, G-Protein-Coupled ,Real-time polymerase chain reaction ,Gene Expression Regulation ,Gene expression ,Animals ,Guanine Nucleotide Exchange Factors ,Platelet ,sense organs ,RNA, Messenger ,Cell activation ,RGS Proteins ,Rho Guanine Nucleotide Exchange Factors ,Signal Transduction - Abstract
Regulators of G protein signalling (RGS) are involved in the negative regulation of cell activation processes and are involved in the pathophysiology of cardiovascular diseases. To get some further evidence for a role of RGS proteins in platelets, we determined the expression profile of RGS-specific mRNA in rat platelets using reverse transcription-polymerase chain reaction (RT-PCR) with a poly dT18 primer and transcript-specific primers. We found that RGS2, RGS3, RGS5, RGS6, RGS10, RGS14, RGS16 and RGS18, Leukemia-associated Rho-GEF factor (LARG), and Galpha interacting protein (GAIP) were differentially expressed in platelets. The highest expression rate was found for RGS18 (about 1.3 fold when compared to GAPDH), followed by LARG, RGS6, RGS10 and RGS16 (0.7 to 0.95), whereas expression rates for RGS2, RGS3, RGS5, RGS14, and GAIP were in a range of 0.1 to 0.3. Our results suggest that G-protein-coupled receptor-mediated signalling in platelet may be regulated mainly by RGS 18, 16, 10, 6, and LARG.
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- 2006
43. Mechanism of isoproterenol-induced RGS2 up-regulation in astrocytes
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Whi Min Lee, Seung-Chun Park, Sang Keun Kim, Man Hee Rhee, Jae Youl Cho, Sung Dae Kim, and Kyoungho Suk
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medicine.medical_specialty ,Gs alpha subunit ,MAP Kinase Signaling System ,Biophysics ,Mitogen-activated protein kinase kinase ,Biochemistry ,p38 Mitogen-Activated Protein Kinases ,Internal medicine ,Cell Line, Tumor ,medicine ,Staurosporine ,Animals ,ASK1 ,c-Raf ,Enzyme Inhibitors ,Protein kinase A ,Molecular Biology ,Protein kinase C ,Protein Kinase C ,MAP kinase kinase kinase ,Dose-Response Relationship, Drug ,Chemistry ,Isoproterenol ,Cell Biology ,Genistein ,Cell biology ,Rats ,Up-Regulation ,Gene Expression Regulation, Neoplastic ,Endocrinology ,Astrocytes ,RGS Proteins ,medicine.drug - Abstract
Regulators of G protein signaling (RGSs) are inducibly expressed in response to various stimuli and the up-regulation of RGSs leads to significant decreases in GPCR responsiveness. Isoproterenol, an adrenergic receptor agonist, stimulated RGS2 mRNA in C6 rat astrocytoma cells. The up-regulation of RGS2 mRNA was abrogated by genistein, a protein tyrosine kinase inhibitor (PTK), and by broad-spectrum protein kinase C (PKC) inhibitors (staurosporine and GF109203X). alpha-Adrenergic antagonist (prazocin), beta-adrenergic antagonist (prazocin), and pertussis toxin only partially blocked the RGS2 up-regulation, suggesting that the RGS2 up-regulation is concomitantly mediated by Galphai, Galphas, and Galphaq. It is interesting to note that SB203580, a potent p38 mitogen-activated protein kinase (MAPK) inhibitor, completely inhibited the isoproterenol-mediated RGS2 expression. In addition, isoproterenol also markedly stimulated RGS2 mRNA in rat primary astrocytes, which were sensitive to SB203580 and staurosporine. Therefore, our data suggest that adrenergic receptor-mediated signaling (induced by isoproterenol) may be involved in the regulation of RGS2 expression in astrocytes via activating PTK, PKC, and p38 MAPK.
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- 2006
44. BRCA1 modulates xenobiotic stress-inducible gene expression by interacting with ARNT in human breast cancer cells
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Sang Keun Kim, Insoo Bae, Hee Jeong Kim, Kum Kum Khanna, Robert Barouki, Eliot M. Rosen, Chi-Heum Cho, and Hyo Jin Kang
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Chromatin Immunoprecipitation ,Cytoplasm ,Aryl hydrocarbon receptor nuclear translocator ,Polychlorinated Dibenzodioxins ,CYP1B1 ,Genetic Vectors ,Breast Neoplasms ,Ligands ,Biochemistry ,chemistry.chemical_compound ,Cell Line, Tumor ,Coactivator ,Cytochrome P-450 CYP1A1 ,Humans ,Molecular Biology ,Transcription factor ,Gene knockdown ,biology ,BRCA1 Protein ,Aryl Hydrocarbon Receptor Nuclear Translocator ,Cell Biology ,Aryl hydrocarbon receptor ,Molecular biology ,Gene Expression Regulation, Neoplastic ,chemistry ,biology.protein ,Carcinogens ,Xenobiotic ,Chromatin immunoprecipitation - Abstract
Previously, we have reported that BRCA1 regulates the expression of various classes of genes, including genes involved in xenobiotic stress responses (Bae, I., Fan, S., Meng, Q., Rih, J. K., Kim, H. J., Kang, H. J., Xu, J., Goldberg, I. D., Jaiswal, A. K., and Rosen, E. M. (2004) Cancer Res. 64, 7893–7909). In the present study, we have investigated the effects of BRCA1 on xenobiotic stress-inducible gene expression. In response to aryl hydrocarbon receptor (AhR) ligands, cytoplasmic AhR becomes activated and then translocates to the nucleus where it forms a complex with the aryl hydrocarbon receptor nuclear translocator (ARNT). Subsequently, the AhR·ARNT complex binds to the enhancer or promoter of genes containing a xenobiotic stress-responsive element and regulates the expression of multiple target genes including cytochrome P450 subfamily polypeptide 1 (CYP1A1). In this study, we have found that endogenous and overexpressed exogenous wild-type BRCA1 affect xenobiotic stress-induced CYP1A1 gene expression. Using a standard chromatin immunoprecipitation assay, we have demonstrated that BRCA1 is recruited to the promoter regions of CYP1A1 and CYP1B1 along with ARNT and/or AhR following xenobiotic exposure. Our findings suggest that BRCA1 may be physiologically important for mounting a normal response to xenobiotic insults and that it may function as a coactivator for ARNT activity. Using immunoprecipitation, Western blotting, and glutathione S-transferase capture assays, a xenobiotic-independent interaction between BRCA1 and ARNT has been identified, although it is not yet known whether this is a direct or indirect interaction. We have also found that the inducibility of CYP1A1 and CYP1B1 transcripts following xenobiotic stress was significantly attenuated in BRCA1 knockdown cells. This reduced inducibility is associated with an altered stability of ARNT and was almost completely reversed in cells transfected with an ARNT expression vector. Finally, we have found that xenobiotic (TCDD) treatments of breast cancer cells containing reduced levels of BRCA1 cause the transcription factor ARNT to become unstable.
- Published
- 2006
45. Histone deacetylase 1 contributes to cell cycle and apoptosis
- Author
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Sun Uk Kim, Dae Yeul Yu, Sang Beom Seo, Sangho Lee, Sang Keun Kim, Ai Guo Wang, and Dong-Seok Lee
- Subjects
Genetically modified mouse ,Cyclin-Dependent Kinase Inhibitor p21 ,Transgene ,Blotting, Western ,Peroxisome Proliferator-Activated Receptors ,Pharmaceutical Science ,Apoptosis ,Mice, Transgenic ,Biology ,Histone Deacetylases ,Mice ,Gene expression ,Animals ,Humans ,DNA Primers ,Pharmacology ,Histone deacetylase 5 ,Base Sequence ,HDAC11 ,Reverse Transcriptase Polymerase Chain Reaction ,Cell Cycle ,General Medicine ,Cell cycle ,HDAC4 ,HDAC1 ,Cancer research ,Tumor Suppressor Protein p53 - Abstract
Histone deacetylases (HDACs) are generally thought to play important roles in human disease. However, little information is available concerning the specific functions of individual HDACs. We previously reported on transgenic mice that expressed human HDAC1 and experienced steatosis and nuclear pleomorphism in their hepatic tissues. To find out if the over-expression of HDAC1 contributes to the expression of genes related to the cell cycle, apoptosis, and lipid metabolism that eventually contribute to the pathological changes in the livers of the transgenic mice, the expression profiles of the related genes in liver tissues were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. The activated human HDAC1 significantly induced the expression levels of mRNA for p53, PPAR-gamma and Bak and reduced the p21 expression level compared with the levels in control littermates. However, the protein levels of p53 and PPAR-gamma were significantly decreased. In conclusion, our results indicate that HDAC1 can regulate gene expression at the mRNA and protein levels independently and that this may be a potential cytopathic factor for hepatic tissue in transgenic mice that over-express HDAC1.
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- 2005
46. Inhibitory role of peroxiredoxin II (Prx II) on cellular senescence
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Jin Man Kim, Ying-Hao Han, Hyun-Sun Kim, Eun-Yi Moon, Sang-Keun Kim, and Dae-Yeul Yu
- Subjects
MAPK/ERK pathway ,Senescence ,Aging ,p38 mitogen-activated protein kinases ,Biophysics ,Biology ,Biochemistry ,Mice ,Peroxiredoxin II ,Structural Biology ,Genetics ,Extracellular ,Animals ,Molecular Biology ,Cells, Cultured ,Cellular Senescence ,chemistry.chemical_classification ,Mice, Knockout ,Reactive oxygen species ,Kinase ,Cell Cycle ,Wild type ,Cell Biology ,Hydrogen Peroxide ,Peroxiredoxins ,Fibroblasts ,Oxidants ,Molecular biology ,Acetylcysteine ,chemistry ,Peroxidases ,embryonic structures ,Peroxiredoxin ,Reactive Oxygen Species - Abstract
Reactive oxygen species (ROS) were generated in all oxygen-utilizing organisms. Peroxiredoxin II (Prx II) as one of antioxidant enzymes may play a protective role against the oxidative damage caused by ROS. In order to define the role of Prx II in organismal aging, we evaluated cellular senescence in Prx II(-/-) mouse embryonic fibroblast (MEF). As compared to wild type MEF, cellular senescence was accelerated in Prx II(-/-) MEF. Senescence-associated (SA)-beta-galactosidase (Gal)-positive cell formation was about 30% higher in Prx II(-/-) MEF. N-Acetyl-l-cysteine (NAC) treatment attenuated SA-beta-Gal-positive cell formation. Prx II(-/-) MEF exhibited the higher G2/M (41%) and lower S (1.6%) phase cells as compared to 24% and 7.3% [corrected] in wild type MEF, respectively. A high increase in the p16 and a slight increase in the p21 and p53 levels were detected in PrxII(-/-) MEF cells. The cellular senescence of Prx II(-/-) MEF was correlated with the organismal aging of Prx II(-/-) mouse skin. While extracellular signal-regulated kinase (ERK) and p38 activation was detected in Prx II(-/-) MEF, ERK and c-Jun N-terminal kinase (JNK) activation was detected in Prx II(-/-) skin. These results suggest that Prx II may function as an enzymatic antioxidant to prevent cellular senescence and skin aging.
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- 2005
47. Transgenic expression of Korean type hepatitis C virus core protein and related mutants in mice
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Sang Keun Kim, Ai Guo Wang, Seong Lan Yu, Tae-Hoon Lee, Hyun Jung Kwon, Wan Fang, Kyung Lib Jang, Young Ho Lee, Dong-Seok Lee, Hyung Moon, Dae Yeul Yu, and Ying Hao Han
- Subjects
Genetically modified mouse ,Hepatitis C virus ,Transgene ,Clinical Biochemistry ,Genetic Vectors ,Molecular Sequence Data ,Gene Expression ,Mice, Transgenic ,In situ hybridization ,Biology ,medicine.disease_cause ,Biochemistry ,Liver disease ,Mice ,Gene expression ,medicine ,Animals ,Amino Acid Sequence ,RNA, Messenger ,Transgenes ,Molecular Biology ,Base Sequence ,Viral Core Proteins ,Wild type ,Hepatitis C ,medicine.disease ,Virology ,Liver ,Hepatitis, Viral, Animal ,Mutation ,Hepatocytes ,Molecular Medicine - Abstract
Hepatitis C virus (HCV) is a major causative agent in liver disease. In order to investigate if Korean type HCV core protein and its related mutants, S99Q and S1161, are cytopathic to liver, three types of transgenic mice were established. The expression of transgenes was confirmed by HCV specific RT-PCR and Western immunoblotting. The livers of all wild type core and S1161 transgenic lineages remained largely histologically normal. However, the livers of the S99Q transgenic mice showed significant high level of cell dysplasia associated with the transgene expression in hepatocytes largely located around the central veins by in situ hybridization analysis. In conclusion, the mutant HCV core protein at S99Q may contribute to the progress of HCV induced liver disease.
- Published
- 2005
48. Gender-dependent hepatic alterations in H-ras12V transgenic mice
- Author
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Sang-Keun Kim, Hyung-Bae Moon, Ai-Guo Wang, Jin Man Kim, Chae Young Hwang, Mi-Ran Lee, Seong-Lan Yu, Dong-Seok Lee, Tae-Hoon Lee, Eun-Yi Moon, Dae-Yeul Yu, Mirang Kim, Ki-Sun Kwon, and Yong-Sung Kim
- Subjects
Genetically modified mouse ,Cyclin-Dependent Kinase Inhibitor p21 ,Male ,medicine.medical_specialty ,Cell cycle checkpoint ,Carcinoma, Hepatocellular ,Ratón ,Transgene ,Mice, Transgenic ,Biology ,Mice ,Sex Factors ,In vivo ,Internal medicine ,Albumins ,Cell Line, Tumor ,medicine ,Animals ,Transgenes ,Promoter Regions, Genetic ,Microinjection ,chemistry.chemical_classification ,Reactive oxygen species ,Hepatology ,Liver Neoplasms ,Endocrinology ,Genes, ras ,chemistry ,Gene Expression Regulation ,Apoptosis ,Hepatocytes ,ras Proteins ,Female ,Tumor Suppressor Protein p53 ,Reactive Oxygen Species - Abstract
Background/Aims Although it has been proposed that Ras and related signal pathways play important roles in hepatocarcinogenesis, appropriate in vivo models are lacking. Methods Two hepatocellular carcinoma lines were established using pronuclear microinjection techniques to create an insertion of the H- ras 12V transgene under the control of the albumin enhancer/promoter. The resulting phenotypes and related molecular events were then examined. Results Male (but not female) transgenic mice older than 2 months showed hepatic alterations with a high degree of reproducibility, as compared to the wild-type mice. The liver/body-weight ratios were lower for the females than for the males. The transgene-carrying line 28 was investigated extensively with respect to molecular differences between the genders. Male hepatocytes showed higher Ras activity and higher reactive oxygen species (ROS) levels than female hepatocytes. The female hepatocytes showed higher expression levels of p53 and p21 Waf1/Cip1 , enhanced cytochrome c release, which correlated with cell cycle arrest, and higher levels of hypodiploid cell formation, as compared to the male hepatocytes. Conclusions The gender-related differences in molecular responses to activated Ras may have implications for the prevalence of hepatic alterations in males. Our transgenic mice represent a potentially valuable animal model for future investigations.
- Published
- 2004
49. 553 DIFFERENTIAL GENE EXPRESSION PROFILE OF HEPATOBLASTOMA AND CHILDHOOD HEPATOCELLULAR CARCINOMA; ITS CLINICAL IMPLICATION
- Author
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Ja June Jang, J. Jin, Kyeong Geun Lee, Su Yeon Park, and Sang-Keun Kim
- Subjects
Oncology ,medicine.medical_specialty ,Hepatoblastoma ,Hepatology ,business.industry ,Internal medicine ,Gene expression ,Medicine ,business ,medicine.disease ,Differential (mathematics) ,Childhood hepatocellular carcinoma - Published
- 2010
- Full Text
- View/download PDF
50. Effect of a Caregiver's Education Program on Stroke Rehabilitation.
- Author
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Sang-Eun Hong, Chang-Hwan Kim, Ee-Jin Kim, Kyung-Lim Joa, Tae-Hyun Kim, Sang-Keun Kim, Hee-Jun Han, Eui-Chang Lee, and Han-Young Jung
- Subjects
STROKE rehabilitation ,MEDICAL personnel ,MEDICAL education ,MEDICAL rehabilitation ,STROKE patients ,MEDICAL care - Abstract
Objective To evaluate effects of caregiver's education program on their satisfaction, as well as patient functional recovery, performed in addition to daily conventional rehabilitation treatment. Methods Three hundred eleven subjects diagnosed with first-onset stroke and transferred to the Department of Physical Medicine and Rehabilitation of Inha University Hospital were surveyed. In 2015, caregivers attended an education program for acute and subacute stroke patients. Patients who received an additional rehabilitation therapy were assigned to the experimental group (n=81), whereas the control group (n=100) consisted of transfer cases in 2014 with only conventional treatment. The experimental group was classified by severity using the Korean version of the National Institutes of Health Stroke Scale (K-NIHSS), which was administered to all 181 subjects, in addition to, the Korean version of the Mini Mental Status Examination (K-MMSE), a Modified Barthel Index (K-MBI), and the Berg Balance Scale (K-BBS). Caregiver satisfaction and burden before and after education programs were assessed using the Canadian Occupational Performance Measure (COPM), as well as family burden and caregiver burnout scales. Results No significant intergroup difference was observed between initial K-NIHSS, K-MMSE, K-BBS, K-MBI scores, and times from admission to transfer. Those with moderate or severe strokes under the experimental condition showed a more significant improvement than the control group as determined by the K-NIHSS and K-BBS, as well as tendential K-MMSE and K-MBI score increases. Satisfaction was significantly greater for family members and formal caregivers of patients with strokes of moderate severity in the experimental group. Conclusion The caregiver's education program for stroke subjects had a positive outcome on patients' functional improvement and caregiver satisfaction. The authors believe that the additional rehabilitation therapy with the education program aids patients to achieve functional improvements for an optimal return to social life. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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