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Lee SH, Chung MK, Sohn YJ, Lee YS, Kang KS. Human Hair Follicle Cells with the Cell Surface Marker CD34 Can Regenerate New Mouse Hair Follicles and Located in the Outer Root Sheath of Immunodeficient Nude Mice. Int J Stem Cells 2014; 1:70-81. [PMID: 24855511 DOI: 10.15283/ijsc.2008.1.1.70] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2008] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The bulge region of hair follicle has been reported as a putative reservoir of hair follicle stem cells. The purpose of this study was to compare hair follice CD34 negative (CD34-) cell with CD34 positive (CD34+) cell and to evaluate the ability to regenerate new hair of immunodeficient nude mouse. METHODS AND RESULTS In this report, we isolated the cells with CD34, known as bulge-negative cell surface marker from cultured human hair follicle cells using by magnetic cell sorting (MACS), injected the cells to immunodeficient nude mouse. To determine immunological characterization, human hair follicle CD34+ cells and CD34- cells were assessed by flow cytometry. The localization of injected-CD34+ cells was assessed on formalin-fixed, paraffin-embedded mouse skin samples by in situ hybridization technique. Our findings show that the human hair follicle cells with cell surface marker CD34 were located in the outer root sheath of nude mouse after transplantation and the cells were able to regenerate new hair follicle in immunodeficient nude mouse. CD34- cells also were able to regenerate follicles in the mouse, however, CD34+ cells were able to regenerate much more hair follicle than CD34- cells. CONCLUSIONS Therefore, the results of this study add new insight into the investigation of CD34 stem cell-related molecule in human hair follicles and suggest that not all human hair follicle stem cells reside in bulge region, but in a lager niche.
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Ooi SQ, Chan RME, Poh LKS, Loke KY, Heng CK, Chan YH, Gan SU, Lee KO, Lee YS. Visfatin and its genetic variants are associated with obesity-related morbidities and cardiometabolic risk in severely obese children. Pediatr Obes 2014; 9:81-91. [PMID: 23447513 DOI: 10.1111/j.2047-6310.2013.00149.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 12/28/2012] [Accepted: 01/10/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Visfatin is an adipokine, associated with obesity and possibly glucose regulation. OBJECTIVE The aim of this study was to examine the association of visfatin and its genetic variants with adiposity, cardiometabolic risk factors and obesity-related morbidities in obese children. METHODS Anthropometric measurements, dual energy X-ray absorptiometry scan, fasting blood samples and oral glucose tolerance tests were performed for 243 obese children. We screened the visfatin gene of 24 obese subjects and then performed genotyping of identified genetic variants in other 219 obese children through direct DNA sequencing. RESULTS Fasting serum visfatin correlated with measures of obesity and liver enzymes and was elevated in obese children with abnormal glucose tolerance and non-alcoholic fatty liver disease. The two upstream single nucleotide polymorphisms, -3187G>A (rs11977021) and -1537C>T (rs61330082), were at complete linkage disequilibrium. The AA genotype of -3187G>A was associated with higher serum visfatin (6.17 ± 0.76 ng mL(-1) vs. 3.92 ± 0.44 ng mL(-1)) and higher triglyceride (1.39 ± 0.08 mmol L(-1) vs. 1.19 ± 0.07 mmol L(-1)) as compared with the GG genotype. There was also a significant linear increase in serum visfatin across GG to GA to AA genotype of -3187G>A, indicating possible additive effect of A allele. The dominant GA + AA genotype model of +21426G>A (rs2302559) was associated with lower serum visfatin (3.83 ± 0.56 ng mL(-1) vs. 5.13 ± 0.34 ng mL(-1)) and lower plasma glucose (4.37 ± 0.08 mmol L(-1) vs. 4.77 ± 0.12 mmol L(-1)) as compared with the GG genotype. CONCLUSION Visfatin and its genetic variants were associated with adiposity, obesity-related morbidities and adverse cardiometabolic parameters. This supported our hypothesis that visfatin plays a significant role in the development of obesity-related morbidities and cardiometabolic risk.
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Kim D, Kim JH, Lee M, Lee YS, Kang S. Experimental investigation into effect of annealing treatment on springback of magnesium alloy sheets. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/143307511x12858956848191] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Yang PLS, Lu Y, Khoo CM, Leow MKS, Khoo EYH, Teo A, Lee YS, Das De S, Chong YS, Gluckman PD, Tai ES, Venkataraman K, Ng CMA. Associations between ethnicity, body composition, and bone mineral density in a Southeast Asian population. J Clin Endocrinol Metab 2013; 98:4516-23. [PMID: 24037892 DOI: 10.1210/jc.2013-2454] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT AND OBJECTIVE Chinese men in Singapore have a higher incidence of hip fractures than Malay and Indian men. We investigated whether there were corresponding ethnic differences in peak bone mineral density (BMD) in young men and whether differences in body composition influenced peak BMD. DESIGN AND SETTING This was a cross-sectional study of healthy volunteers in a tertiary medical center. PARTICIPANTS A total of 100 Chinese, 82 Malay, and 80 Indian men aged 21 to 40 years, with body mass index between 18 and 30 kg/m(2) underwent dual-energy x-ray absorptiometry to assess BMD, lean mass (LM) and fat mass (FM), and magnetic resonance imaging to quantify abdominal subcutaneous and visceral adipose tissue. Multiple linear regression models, with adjustment for age and height (as a proxy for skeletal size), were used. RESULTS Malay and Indian men had significantly higher BMD than Chinese men at the lumbar spine (Malay: B, 0.06 ± 0.02, P = .001; Indian: B, 0.03 ± 0.02, P = .049), femoral neck (Malay: B 0.04 ± 0.02, P = .034; Indian: B, 0.04 ± 0.02, P = .041), hip (Malay: B, 0.05 ± 0.02, P = .016; Indian: B, 0.06 ± 0.02, P = .001), and ultradistal radius (Malay: B, 0.03 ± 0.01, P < .001; Indian: B, 0.02 ± 0.01, P = .029), and this difference was retained after adjustment for LM and FM, except in Malay men at the femoral neck and in Indian men at the ultradistal radius. LM was an important independent determinant of BMD at all sites, whereas FM, subcutaneous adipose tissue, and visceral adipose tissue were not significantly associated with BMD at any site. CONCLUSIONS Lower peak BMD in Chinese men may partly explain the higher fracture incidence in this ethnic group. Further studies are needed to elucidate the reasons for these ethnic differences in bone accumulation.
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Kim BJ, Lee YS, Lee SY, Park SY, Dieplinger H, Yea K, Lee SH, Koh JM, Kim GS. Afamin stimulates osteoclastogenesis and bone resorption via Gi-coupled receptor and Ca2+/calmodulin-dependent protein kinase (CaMK) pathways. J Endocrinol Invest 2013; 36:876-82. [PMID: 23698732 DOI: 10.3275/8975] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Afamin was recently identified as a novel osteoclast-derived coupling factor that can stimulate the in vitro and in vivo migration of preosteoblasts. AIM In order to understand in more detail the biological roles of afamin in bone metabolism, we investigated its effects on osteoclastic differentiation and bone resorption. METHODS Osteoclasts were differentiated from mouse bone marrow cells. Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were considered as osteoclasts, and the resorption area was determined by incubating the cells on dentine discs. The intracellular cAMP level was determined using a direct enzyme immunoassay. Signaling pathways were investigated using western blot and RT-PCR. Recombinant afamin was administered exogenously to bone cell cultures. RESULTS Afamin stimulated both osteoclastogenesis and in vitro bone resorption. Consistently, the expressions of osteoclast differentiation markers were significantly increased by afamin. Although afamin mainly affected the late-differentiation stages of osteoclastogenesis, the expression levels of receptor activator of nuclear factor-κB ligand (RANKL)-dependent signals were not changed. Afamin markedly decreased the levels of intracellular cAMP with reversal by pretreatment with pertussis toxin (PTX), a specific inhibitor of Gi-coupled receptor signaling. In addition, PTX almost completely blocked afamin-stimulated osteoclastogenesis. Furthermore, pretreatment with KN93 and STO609 - Ca2+/cal - mo dulin-dependent protein kinase (CaMK) and CaMK kinase inhibitors, respectively - significantly prevented decreases in the intracellular cAMP level by afamin while attenuating afamin-stimulated osteoclastogenesis. CONCLUSION Afamin enhances osteoclastogenesis by decreasing intracellular cAMP levels via Gi-coupled receptor and CaMK pathways.
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Kang JH, Kim YK, Park JY, Noh ES, Jeong JE, Lee YS, Choi TJ. Development of microsatellite markers for a hard-shelled mussel, Mytilus coruscus, and cross-species transfer. GENETICS AND MOLECULAR RESEARCH 2013; 12:4009-17. [PMID: 24089090 DOI: 10.4238/2013.september.27.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The Korean mussel Mytilus coruscus, an endemic marine bivalve mollusk, is economically important. Its population is currently decreasing due to overexploitation and invasion of a more competitive species, Mytilus galloprovincialis. In this study, microsatellite markers for M. coruscus were developed using a cost-effective pyrosequencing technique. Among the 33,859 dinucleotide microsatellite sequences identified, 176 loci that contained more than 8 CA, CT, or AT repeats were selected for primer synthesis. Sixty-four (36.4%) primer sets were produced from the 100- to 200-bp polymerase chain reaction products obtained from 2 M. coruscus individuals. Twenty of these were chosen to amplify DNA from 82 M. coruscus individuals, and 18 polymorphic loci and 2 monomorphic loci were selected as microsatellite markers. The number of alleles and the allele richness of the polymorphic loci ranged from 2 to 22 and from 2.0 to 19.7 with means of 10.8 and 10.1, respectively. Null alleles were detected for all but three loci, which resulted in an observed heterozygosity lower than the expected heterozygosity and therefore an excess of homozygotes. In a cross-species transfer analysis of these markers using 7 Mytilidae species, the locus Mc65 was amplified from all species tested and was found to be polymorphic in all of them. Among the species, M. galloprovincialis, Lithophaga curta, and Hormomya mutabilis showed the same transferability of 25%, but the five amplified loci were polymorphic only in M. galloprovincialis and H. mutabilis. These microsatellite markers may be useful for future resource management and artificial production of juveniles for aquaculture.
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Pilon DV, Lui CH, Han TH, Shrekenhamer D, Frenzel AJ, Padilla WJ, Lee YS, Gedik N. Spin-induced optical conductivity in the spin-liquid candidate herbertsmithite. PHYSICAL REVIEW LETTERS 2013; 111:127401. [PMID: 24093299 DOI: 10.1103/physrevlett.111.127401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Indexed: 06/02/2023]
Abstract
We report a direct measurement of the low-frequency optical conductivity of large-area single-crystal herbertsmithite, a promising spin-liquid candidate material, by means of terahertz time-domain spectroscopy. In the spectral range below 1.4 THz, we observe a contribution to the real part of the in-plane conductivity σ(ab)(ω) from the spin degree of freedom. This spin-induced conductivity exhibits a power-law dependence on frequency σ(ab)(ω) ~ ω(β) with β ≈ 1.4. Our observation is consistent with the theoretically predicted low-frequency conductivity arising from an emergent gauge field of a gapless U(1) Dirac spin liquid.
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Karthikeyan K, Amaresh S, Kim KJ, Kim SH, Chung KY, Cho BW, Lee YS. A high performance hybrid capacitor with Li2CoPO4F cathode and activated carbon anode. NANOSCALE 2013; 5:5958-5964. [PMID: 23708774 DOI: 10.1039/c3nr00760j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
For the first time, we report the possibility of utilizing Li2CoPO4F as a novel cathode material for hybrid capacitor applications. Li2CoPO4F powders were prepared by a conventional two-step solid state method. A hybrid cell was fabricated using Li2CoPO4F as the cathode along with activated carbon (AC) as the anode in 1 M LiPF6 dissolved in 1 : 1 EC/DMC electrolyte and its electrochemical properties were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and constant current charge-discharge (C-D) techniques. The Li2CoPO4F/AC cell is capable of delivering a discharge capacitance of 42 F g(-1) at 150 mA g(-1) current density within 0-3 V region having excellent coulombic efficiency of over 99% even after 1000 cycles. Furthermore, the Li2CoPO4F/AC cell exhibited excellent rate performance with an energy density of ~24 W h kg(-1) at 1100 mA g(-1) current and maintained about 92% of its initial value even after 30,000 C-D cycles. Electrochemical impedance spectroscopy was conducted to corroborate the results that were obtained and described.
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Kim H, Lee SK, Hong MW, Park SR, Lee YS, Kim JW, Lee HK, Jeong DK, Song YH, Lee SJ. Association of a single nucleotide polymorphism in the akirin 2 gene with economically important traits in Korean native cattle. Anim Genet 2013; 44:750-3. [PMID: 23718263 DOI: 10.1111/age.12055] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2013] [Indexed: 11/29/2022]
Abstract
The akirin 2 gene, located on chromosome 9 in cattle, was previously reported to be associated with nuclear factor-kappa B (NF-κB), involved in immune reactions and marbling of meat. To determine whether a single nucleotide polymorphism (SNP) in akirin 2 is associated with economically important traits of Korean native cattle, the c.*188G>A SNP DNA marker in the 3'-UTR region of akirin 2 was analyzed for its association with carcass weight, longissimus muscle area and marbling. The c.*188G>A SNP was genotyped by polymerase chain reaction restriction fragment length polymorphism, and the frequency of the AA, AG, and GG genotypes were 6.82%, 71.29% and 21.88% respectively. This SNP was significantly associated with longissimus muscle area (Bonferroni corrected P < 0.05), and marbling score (Bonferroni corrected P < 0.01). These results suggest that the c.*188G>A SNP of akirin 2 might be useful as a DNA marker for longissimus muscle area and marbling scores in Korean native cattle.
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Lee JY, Shin TJ, Choi JM, Seo KS, Kim HJ, Yoon TG, Lee YS, Han H, Chung HJ, Oh Y, Jung SJ, Shin KJ. Antinociceptive curcuminoid, KMS4034, effects on inflammatory and neuropathic pain likely via modulating TRPV1 in mice. Br J Anaesth 2013; 111:667-72. [PMID: 23719767 DOI: 10.1093/bja/aet176] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Curcumin, the active ingredient of turmeric (Curcuma longa), has a wide range of beneficial effects including anti-inflammation and analgesia. However, poor bioavailability of curcumin hinders its clinical application. To overcome this limitation, we modified the structure of curcumin and synthesized new derivatives with favourable pharmacokinetic profiles. Recently, curcumin has been shown to have an antagonizing effect on transient receptor potential vanilloid type 1 (TRPV1) ion channels. We investigated the antinociceptive activity of KMS4034 which had the most favourable pharmacokinetics among the tested curcumin derivatives. METHODS To evaluate the mechanism of the antinociceptive effects of KMS4034, capsaicin (I(CAP))- and heat (I(heat))-induced currents in TRPV1 expressing HEK293 cells were observed after the application of KMS4034. Nociceptive behavioural measurement using the hot-plate test, formalin test, and chronic constriction injury (CCI) model were evaluated in mice. Also, calcitonin gene-related peptide (CGRP) was stained immunohistochemically in the L4/5 dorsal horns in mice with neuropathic pain. RESULTS I(CAP) (P<0.01) and I(heat) (P<0.05) of TRPV1 were significantly blocked by 10 μM KMS4034. Behaviourally, noticeable antinociceptive effects after 10 mg kg(-1) of KMS4034 treatment were observed in the first (P<0.05) and second phases (P<0.05) of the formalin and hot-plate tests. The mechanical threshold of CCI mice treated with 10 mg kg(-1) KMS4034 was significantly increased compared with control. Immunohistochemical CGRP expression was decreased in the lamina I-II of the lumbar dorsal horns in KMS4034-treated CCI mice compared with the control (P<0.05). CONCLUSIONS KMS4034 may be an effective analgesic for various pain conditions.
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Lee YS, Lee SJ, Seo KW, Bae JU, Park SY, Kim CD. Homocysteine induces COX-2 expression in macrophages through ROS generated by NMDA receptor-calcium signaling pathways. Free Radic Res 2013; 47:422-31. [PMID: 23485152 DOI: 10.3109/10715762.2013.784965] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Homocysteine (Hcy) at elevated levels is a putative risk factor for many cardiovascular disorders including atherosclerosis. In the present study, we investigated the effect of Hcy on the expression of cyclooxygenase (COX)-2 in murine macrophages and the mechanisms involved. Hcy increased the expression of COX-2 mRNA and protein in dose- and time-dependent manners, but did not affect COX-1 expression. Hcy-induced COX-2 expression was attenuated not only by the calcium chelators, EGTA and BAPTA-AM, but also by an antioxidant, N-acetylcysteine. Calcium chelators also attenuated Hcy-induced reactive oxygen species (ROS) production in macrophages, indicating that Hcy-induced COX-2 expression might be mediated through ROS generated by calcium-dependent signaling pathways. In another series of experiments, Hcy increased the intracellular concentration of calcium in a dose-dependent manner, which was attenuated by MK-801, an N-methyl-D-aspartate (NMDA) receptor inhibitor, but not by bicuculline, a gamma-aminobutyric acid receptor inhibitor. Molecular inhibition of NMDA receptor using small interfering RNA also attenuated Hcy-induced increases in intracellular calcium. Furthermore, both ROS production and Hcy-induced COX-2 expression were also inhibited by MK-801 as well as by molecular inhibition of NMDA receptor. Taken together, these findings suggest that Hcy enhances COX-2 expression in murine macrophages by ROS generated via NMDA receptor-mediated calcium signaling pathways.
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Aris IM, Soh SE, Tint MT, Liang S, Chinnadurai A, Saw SM, Kwek K, Godfrey KM, Gluckman PD, Chong YS, Yap FKP, Lee YS. Body fat in Singaporean infants: development of body fat prediction equations in Asian newborns. Eur J Clin Nutr 2013; 67:922-7. [PMID: 23549200 DOI: 10.1038/ejcn.2013.69] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/21/2013] [Accepted: 02/22/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Prediction equations are commonly used to estimate body fat from anthropometric measurements, but are population specific. We aimed to establish and validate a body composition prediction formula for Asian newborns, and compared the performance of this formula with that of a published equation. SUBJECTS/METHODS Among 262 neonates (174 from day 0, 88 from days 1-3 post delivery) from a prospective cohort study, body composition was measured using air-displacement plethysmography (PEA POD), with standard anthropometric measurements, including triceps and subscapular skinfolds. Using fat mass measurement by PEA POD as a reference, stepwise linear regression was utilized to develop a prediction equation in a randomly selected subgroup of 62 infants measured on days 1-3, which was then validated in another subgroup of 200 infants measured on days 0-3. RESULTS Regression analyses revealed subscapular skinfolds, weight, gender and gestational age were significant predictors of neonatal fat mass, explaining 81.1% of the variance, but not triceps skinfold or ethnicity. By Bland-Altman analyses, our prediction equation revealed a non-significant bias with limits of agreement (LOA) similar to those of a published equation for infants measured on days 1-3 (95% LOA: (-0.25, 0.26) kg vs (-0.23, 0.21) kg) and on day 0 (95% LOA: (-0.19, 0.17) kg vs (-0.17, 0.18) kg). The published equation, however, exhibited a systematic bias in our sample. CONCLUSIONS Our equation requires only one skinfold site measurement, which can significantly reduce time and effort. It does not require the input of ethnicity and, thus, aid its application to other Asian neonatal populations.
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Kim M, Jin YB, Lee K, Lee YS. A new antiallergic agent that binds to dimerized translationally controlled tumor protein and inhibits allergic symptoms is nontoxic. Hum Exp Toxicol 2013; 32:1119-25. [PMID: 23536520 DOI: 10.1177/0960327113477873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dimerized translationally controlled tumor protein (dTCTP) plays a role in allergic diseases. A 7-mer peptide, dimerized translationally binding protein 2 (dTBP2), binds to dTCTP and inhibits dTCTP, suggesting that the 7-mer peptide may have therapeutic potential. We assessed the safety of dTBP2 by examining its cytotoxicity to both human bronchial epithelial cells and mice. dTBP2 did not cause cytotoxicity to the epithelial cells in concentrations up to 100 μg/ml. Also, dTBP2 caused no adverse effects upon repeated administration of 50 mg/kg over 24 h to mice. Hence, we conclude that dTBP2 is a safe candidate drug for use in the therapy of allergic diseases.
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Park JW, Jang AN, Song JH, Park CY, Lee YS. Electronic structure of Zn doped Fe3O4 thin films. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:1895-1898. [PMID: 23755615 DOI: 10.1166/jnn.2013.6996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We investigated the effect of Zn doping on the electronic property of magnetite by using optical spectroscopy. The (Zn(x)Fe(1-x))Fe2O4 (ZFFO) (x = 0, 0.2, 0.4, and 0.5) samples were prepared by PLD technique. The XRD measurement revealed that all the samples have an inverse spinel-type of crystalline structure. The M-H curves indicate that the saturation magnetization reduces with the increasing x. From the spectroscopic ellipsometry and infrared spectroscopy, we found that the doping of nonmagnetic Zn2+ ions leads to the dramatic change in the electronic structure of the ZFFO films. We discuss the correlation of our spectra with the electric and magnetic properties of the ZFFO films.
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Kim DH, Lee DJ, Park JW, Lee YS. Synthesis and optical characterization of SrHfO3 nano-crystals synthesized by using the combustion method. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:1845-1847. [PMID: 23755603 DOI: 10.1166/jnn.2013.6988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We synthesized SrHfO3 nano-crystals (NCs) by using the combustion method, and investigated their emission property using 325 nm photo-excitation. The as-grown SrHfO3 NCs were annealed at different temperatures from 700 degrees C to 1450 degrees C. The X-ray diffraction analysis revealed that all the samples are of a single phase, and the grain size increases with the higher temperature annealing. Interestingly, it is found that in contrast to the bulk case, the SrHfO3 NCs show a strong blue emission even at room temperature. The strong dependence of the visible emission on annealing temperatures and grain sizes indicated that the effects of grain size and oxygen vacancies may play a role in forming the observed visible emission band for SrHfO3 NCs. We also compare our findings with the case of similar material, SrZrO3.
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Yoon SY, Kim TB, Baek S, Kim S, Kwon HS, Lee YS, Lee T, Jang AS, Chang YS, Cho SH, Choi BW, Park JW, Nham DH, Yoon HJ, Cho YJ, Park CS, Moon HB, Cho YS. The impact of total antioxidant capacity on pulmonary function in asthma patients. Int J Tuberc Lung Dis 2013; 17:1036-42. [PMID: 23044449 DOI: 10.5588/ijtld.12.0842] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Oxidative stress, mediated by an imbalance between oxidants and antioxidants, contributes significantly to the pathogenesis of asthma. OBJECTIVE To evaluate the impact of serum total antioxidant capacity (TAC) on the pulmonary function of Korean asthma patients. METHOD A total of 104 adult asthma patients enrolled from the COREA (Cohort for Reality and Evolution of Adult Asthma in Korea) programme participated in the study. Baseline clinical parameters at enrolment, and the results of pulmonary function tests at baseline and 1 and 2 years after enrolment were collected. TAC at baseline was measured using a Trolox-equivalent antioxidant capacity assay. Patients were divided into two groups based on TAC levels, and various clinical parameters were compared. RESULT Serum TAC levels correlated with forced expiratory volume in 1 second (FEV(1)) at baseline (r = 0.22, P = 0.03). The group with higher baseline TAC levels maintained greater mean FEV(1) both 1 and 2 years after enrolment, even after adjusting for sex, age, height, weight, body mass index and smoking status. CONCLUSION These results suggest an important link between serum TAC levels and pulmonary function, indicating that higher TAC levels may be a biomarker for favourable prognosis in asthma patients.
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Hong DG, Park NY, Chong GO, Cho YL, Park IS, Jeong MJ, Park JY, Lee YS. The correlation between expression of synuclein-gamma, glucose transporter-1, and survival outcomes in endometrioid endometrial carcinoma. EUR J GYNAECOL ONCOL 2013; 34:128-131. [PMID: 23781582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PURPOSE To evaluate the correlation between immunohistochemical expression of synuclein-gamma, glucose transporter-1, and survival outcomes in endometrioid endometrial carcinoma. MATERIALS AND METHODS A tissue microarray was constructed using formalinfixed, paraffin-embedded tissue that included 23 early and 18 advanced cases. The intensity and area of the immunohistochemical reactions were evaluated using the semi-quantitative scoring system. RESULTS Synuclein-y expression was higher in the advanced stage, although it was not statistically significant (p = 0.51). Glucose transporter-1 was overexpressed in the advanced stage (p = 0.01). Synuclein-gamma (score = 0 vs > 0) and glucose transporter-1 (score < or = 7 vs > 7) did not show any differences in overall survival (p = 0.54, p = 0.48) and disease-free survival (p = 0.61, p = 0.14). CONCLUSION In this study the expression of synuclein-y and glucose transporter-1 were not considered to be a prognostic factor and were not related with survival outcomes in endometrioid endometrial carcinoma.
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Singh DK, Lee YS. Nonconventional spin glass transition in a chemically ordered pyrochlore. PHYSICAL REVIEW LETTERS 2012; 109:247201. [PMID: 23368369 DOI: 10.1103/physrevlett.109.247201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Indexed: 06/01/2023]
Abstract
We report on the study of unusual spin glass properties in the geometrically frustrated pyrochlore Tb(2)Mo(2)O(7), T(g) ~/= 24 K. The analysis of the nonlinear part of dc and complex susceptibilities, near the glass transition regime, suggests the existence of a statistical distribution of relaxation times in short-range ordered ferromagnetic clusters. In addition, the magnetic spins are not sufficiently frozen below the glass transition temperature, which is apparently responsible for the nonequilibrium scaling behavior of the static critical exponents of nonlinear susceptibilities. Our report is expected to shed new light in understanding the freezing properties of frustrated pyrochlores with short-range ferromagnetic interactions.
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Hsu CC, Chang HY, Huang MC, Hwang SJ, Yang YC, Lee YS, Shin SJ, Tai TY. HbA1c variability is associated with microalbuminuria development in type 2 diabetes: a 7-year prospective cohort study. Diabetologia 2012; 55:3163-72. [PMID: 22923064 DOI: 10.1007/s00125-012-2700-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/25/2012] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS HbA(1c) variability has been shown to be an independent risk factor for nephropathy in patients with type 1 diabetes. In this study, we aimed to explore the association between HbA(1c) variability and microalbuminuria development in patients with type 2 diabetes. We also intended to test the applicability of serially measured HbA(1c) over 2 years for this risk assessment. METHODS Between 2003 and 2005, we recruited 821 middle-aged normoalbuminuric individuals with type 2 diabetes and followed them through to the end of 2010. The average follow-up time was 6.2 years. We defined microalbuminuria as a urine albumin to creatinine ratio of 30 mg/g (3.4 mg/mmol) or higher. HbA(1c) variability was calculated by the SD of serially measured HbA(1c). The Cox proportional hazards model was used to evaluate the association between HbA(1c) SD quartile and development of microalbuminuria. RESULTS The incidence of microalbuminuria for the overall population was 58.4, 58.6, 60.8 and 91.9 per 1,000 person-years for Q1- to Q4-adjusted HbA(1c) SD, respectively (p for trend = 0.042). Compared with patients in Q1, those in Q4 were about 37% more likely to develop microalbuminuria. The HR derived from a series of 2 year HbA(1c) measurements was similar to that from data collection for longer than 4 years. CONCLUSIONS/INTERPRETATION In addition to mean HbA(1c) values, HbA(1c) variability, even measured as early as 2 years, is independently associated with the development of microalbuminuria in patients with type 2 diabetes.
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95
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Wang YH, Hsieh D, Sie EJ, Steinberg H, Gardner DR, Lee YS, Jarillo-Herrero P, Gedik N. Measurement of intrinsic dirac fermion cooling on the surface of the topological insulator Bi2Se3 using time-resolved and angle-resolved photoemission spectroscopy. PHYSICAL REVIEW LETTERS 2012; 109:127401. [PMID: 23005985 DOI: 10.1103/physrevlett.109.127401] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Indexed: 06/01/2023]
Abstract
We perform time- and angle-resolved photoemission spectroscopy of a prototypical topological insulator (TI) Bi(2)Se(3) to study the ultrafast dynamics of surface and bulk electrons after photoexcitation. By analyzing the evolution of surface states and bulk band spectra, we obtain their electronic temperature and chemical potential relaxation dynamics separately. These dynamics reveal strong phonon-assisted surface-bulk coupling at high lattice temperature and total suppression of inelastic scattering between the surface and the bulk at low lattice temperature. In this low temperature regime, the unique cooling of Dirac fermions in TI by acoustic phonons is manifested through a power law dependence of the surface temperature decay rate on carrier density.
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96
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Oh YC, Kang OH, Kim SB, Mun SH, Park CB, Kim YG, Kim YI, Lee YS, Han SH, Keum JH, Shin DW, Ma JY, Kwon DY. Anti-inflammatory effect of sinomenine by inhibition of pro-inflammatory mediators in PMA plus A23187-stimulated HMC-1 Cells. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2012; 16:1184-1191. [PMID: 23047501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND OBJECTIVES Sinomenine is an alkaloid compound and a prominent anti-inflammatory agent found in the root of the climbing plant Sinomenium acutum. However, its effects on the mechanism of human mast cell line (HMC)-1-mediated inflammation remained unknown. MATERIALS AND METHODS To provide insight into the biological effects of sinomenine, we examined its influence on the pro-inflammatory cytokine production in HMC-1 cells stimulated by phorbol 12-myristate-13-acetate (PMA) plus A23187 by evaluating the stimulated cells in the presence or absence of sinomenine. In the present study, the pro-inflammatory cytokine production was measured using ELISA, Reverse Transcription-polymerase chain reaction (RT-PCR) and nuclear factor (NF)-kappaB, mitogen-activated protein kinases (MAPKs) pathway activation, as determined by Western blot analysis. Also, cyclooxygenase (COX)-2 expression was measured through Western blot and RT-PCR analysis. RESULTS Sinomenine inhibited the pro-inflammatory cytokine production induced by PMA plus A23187 in a dose-dependent manner. Furthermore, sinomenine inhibited the phosphorylations of extracellular signal-regulated kinase (ERK) and p38 MAPKs as well as the translocation of NF-kappaB p65 through reduced IkappaBalpha degradation. In addition, sinomenine suppressed COX-2 protein and mRNA expression dose-dependently. CONCLUSIONS Taken together, the results of this study indicate that the anti-inflammatory effects of sinomenine may occur via the inhibition of pro-inflammatory cytokine and COX-2 production through the inhibition of MAPKs and NF-kappaB pathway activation by PMA plus A23187 stimulation in HMC-1 cells.
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97
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Lee YS, Choi I, Ning Y, Kim NY, Khatchadourian V, Yang D, Chung HK, Choi D, LaBonte MJ, Ladner RD, Nagulapalli Venkata KC, Rosenberg DO, Petasis NA, Lenz HJ, Hong YK. Interleukin-8 and its receptor CXCR2 in the tumour microenvironment promote colon cancer growth, progression and metastasis. Br J Cancer 2012; 106:1833-41. [PMID: 22617157 PMCID: PMC3364111 DOI: 10.1038/bjc.2012.177] [Citation(s) in RCA: 226] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Colorectal cancer (CRC) is a leading cause of death in the United States. Increased level of interleukin-8 (IL-8) and CXCR2 on tumours and in the tumour microenvironment has been associated with CRC growth, progression and recurrence in patients. Here, we aimed to evaluate the effects of tissue microenvironment-encoded IL-8 and CXCR2 on colon cancer progression and metastasis. METHODS A novel immunodeficient, skin-specific IL-8-expressing transgenic model was generated to evaluate colon cancer growth and metastasis. Syngeneic mouse colon cancer cells were grafted in CXCR2 knockout (KO) mice to study the contribution of CXCR2 in the microenvironment to cancer growth. RESULTS Elevated levels of IL-8 in the serum and tumour microenvironment profoundly enhanced the growth of human and mouse colon cancer cells with increased peri-tumoural angiogenesis, and also promoted the extravasation of the cancer cells into the lung and liver. The tumour growth was inhibited in CXCR2 KO mice with significantly reduced tumour angiogenesis and increased tumour necrosis. CONCLUSION Increased expression of IL-8 in the tumour microenvironment enhanced colon cancer growth and metastasis. Moreover, the absence of its receptor CXCR2 in the tumour microenvironment prevented colon cancer cell growth. Together, our study demonstrates the critical roles of the tumour microenvironment-encoded IL-8/CXCR2 in colon cancer pathogenesis, validating the pathway as an important therapeutic target.
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98
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Teo AE, Ng AC, Venkataraman K, Tai ES, Lee YS, Khoo EY, Khoo CM, Sadananthan SA, Velan SS, Zagorodnov V, Chong YS, Gluckman P, Leow MK. Ethnic differences in the association of fat and lean mass with bone mineral density in the Singapore population. BMC Proc 2012. [PMCID: PMC3426076 DOI: 10.1186/1753-6561-6-s4-p43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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99
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Choi JG, Lee MW, Choi SE, Kim MH, Kang OH, Lee YS, Chae HS, Obiang-Obounou B, Oh YC, Kim MR, Shin DW, Lee JH, Kwon DY. Antibacterial activity of bark of Alnus pendula against methicillin-resistant Staphylococcus aureus. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2012; 16:853-859. [PMID: 22953631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND OBJECTIVES Methicillin-resistant Staphylococcus aureus (MRSA) infections are a rapidly growing health problem around the globe. Recently, there has been considerable interest in the use of plant materials as an alternative method to control pathogenic microorganisms. In this study we evaluated the antibacterial activity of bark of Alnus pendula against MRSA. MATERIALS AND METHODS The MIC determination was done using the microdilution broth method and bacterial growth was determined by measuring optical density using spectrophotometer. RESULTS Alnus pendula bark EtOH extract and fractions (F-1, -2, -3 and -4) were investigated against MRSA. The most active fractions (F-3 and F-4) led to the isolation of oregonin (ORE) and hirsutanone (HIR). These compounds were active against MRSA strains with minimum inhibitory concentrations (MICs) ranging from 31.25 to 250 microg/ml MIC and 2 MIC of HIR completely inhibited the growth of MRSA. CONCLUSIONS The bark EtOH extract of Alnus Pendula has potent antibacterial activity against MRSA.
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100
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Choi SW, Han JM, Bae YJ, Lee YS, Cho YS, Moon HB, Kim TB. Lessons from two cases of anaphylaxis to proton pump inhibitors. J Clin Pharm Ther 2012; 37:614-6. [PMID: 22642701 DOI: 10.1111/j.1365-2710.2012.01348.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Proton pump inhibitors (PPIs), which are widely used for the treatment of peptic ulcers and gastroesophageal diseases, reduce both basal and stimulated gastric acid secretion by inhibiting the parietal cell enzyme H(+)-K(+)-adenosine triphosphatase. There have been several reports of hypersensitivity reactions to PPIs but anaphylaxis is very rare. We report on two cases of anaphylaxis to PPIs. CASE SUMMARY Our two interesting and instructive cases of anaphylaxis to PPIs relate to the orally disintegrating form of lansoprazole and omeprazole. The first patient had taken esomeprazole 20 mg/day for 1 month without any side effects before experiencing anaphylaxis to lansoprazole. To our knowledge, this is the first report of anaphylaxis to the orally disintegrating form of lansoprazole. In the second case, the patient was misdiagnosed with penicillin allergy which she suffered from earlier. WHAT IS NEW AND CONCLUSION Physicians need to be more aware of the possibility of hypersensitivity to PPIs.
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