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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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Sulima A, Cheng K, Jacobson AE, Rice KC, Gawrisch K, Lee YS. Z and E rotamers of N-formyl-1-bromo-4-hydroxy-3-methoxymorphinan-6-one and their interconversion as studied by 1H/13C NMR spectroscopy and quantum chemical calculations. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2013; 51:82-8. [PMID: 23233124 PMCID: PMC3551572 DOI: 10.1002/mrc.3909] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 11/08/2012] [Accepted: 11/12/2012] [Indexed: 06/01/2023]
Abstract
N-Formyl-1-bromo-4-hydroxy-3-methoxymorphinan-6-one (compound 2), an important intermediate in the NIH Opiate Total Synthesis, presumably exists as a mixture of two rotamers (Z and E) in both CHCl(3) and DMSO at room temperature due to the hindered rotation of its N-C18 bond in the amide moiety. By comparing the experimental (1)H and (13)C chemical shifts of a single rotamer and the mixture of compound 2 in CDCl(3) with the calculated chemical shifts of the geometry optimized Z and E rotamers utilizing density functional theory, the crystalline rotamer of compound 2 was characterized as having the E configuration. The energy barrier between the two rotamers was also determined with the temperature dependence of (1)H and (13)C NMR coalescence experiments, and then compared with that from the reaction path for the interconversion of the two rotamers calculated at the level of B3LYP/6-31G*. Detailed geometry of the ground state and the transition states of both rotamers are given and discussed.
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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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Guérard F, Lee YS, Tripier R, Szajek LP, Deschamps JR, Brechbiel MW. Investigation of Zr(IV) and 89Zr(IV) complexation with hydroxamates: progress towards designing a better chelator than desferrioxamine B for immuno-PET imaging. Chem Commun (Camb) 2012; 49:1002-4. [PMID: 23250287 DOI: 10.1039/c2cc37549d] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Single crystal X-ray diffraction shows that Zr(iv) forms an octa-coordinated complex with 4 bidentate hydroxamates whose solution structures were investigated by utilizing density functional theory at the level of B3LYP/DGDZVP. Stability constants obtained by potentiometry were in accordance with the tendency observed when radiolabeling with (89)Zr.
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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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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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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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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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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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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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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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Pan ZH, Fedorov AV, Gardner D, Lee YS, Chu S, Valla T. Measurement of an exceptionally weak electron-phonon coupling on the surface of the topological insulator Bi2Se3 using angle-resolved photoemission spectroscopy. PHYSICAL REVIEW LETTERS 2012; 108:187001. [PMID: 22681106 DOI: 10.1103/physrevlett.108.187001] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Indexed: 06/01/2023]
Abstract
Gapless surface states on topological insulators are protected from elastic scattering on nonmagnetic impurities which makes them promising candidates for low-power electronic applications. However, for widespread applications, these states should have to remain coherent at ambient temperatures. Here, we studied temperature dependence of the electronic structure and the scattering rates on the surface of a model topological insulator, Bi2Se3, by high-resolution angle-resolved photoemission spectroscopy. We found an extremely weak broadening of the topological surface state with temperature and no anomalies in the state's dispersion, indicating exceptionally weak electron-phonon coupling. Our results demonstrate that the topological surface state is protected not only from elastic scattering on impurities, but also from scattering on low-energy phonons, suggesting that topological insulators could serve as a basis for room-temperature electronic devices.
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Han KJ, Kim JY, Chung NS, Lee HR, Lee YS. Trabecular microstructure of the human lunate in Kienbock's disease. J Hand Surg Eur Vol 2012; 37:336-41. [PMID: 21965181 DOI: 10.1177/1753193411422337] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The trabecular microstructure of normal lunates and lunates with Kienböck's disease was investigated using micro-computed tomography (micro-CT). Five lunates with advanced Kienböck's disease were obtained during lunate excision and scaphocapitate fusion, and five control lunates were from embalmed cadavers. Microstructural morphometric parameters were measured using micro-CT images. Trabeculations of lunates with Kienböck's disease were 2.67 times denser and 1.84 times thicker than those of normal lunates. Furthermore, bone surface areas were 1.43 times greater and bone volume 2.67 times greater, and structural model indices were significantly lower in lunates with Kienböck's disease. The study estimated that high mechanical stress would be applied to lunates with Kienböck's disease, and suggests that new bone formation and collapse may play important roles in the microstructural changes in the lunate with advanced Kienböck's disease.
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Lee YS, Siméon FG, Briard E, Pike VW. Solution structures of the prototypical 18 kDa translocator protein ligand, PK 11195, elucidated with 1H/13C NMR spectroscopy and quantum chemistry. ACS Chem Neurosci 2012; 3:325-35. [PMID: 22860199 DOI: 10.1021/cn3000108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 02/08/2012] [Accepted: 02/14/2012] [Indexed: 11/29/2022] Open
Abstract
Eighteen kilodalton translocator protein (TSPO) is an important target for drug discovery and for clinical molecular imaging of brain and peripheral inflammatory processes. PK 11195 [1a; 1-(2-chlorophenyl)-N-methyl-(1-methylpropyl)-3-isoquinoline carboxamide] is the major prototypical high-affinity ligand for TSPO. Elucidation of the solution structure of 1a is of interest for understanding small-molecule ligand interactions with the lipophilic binding site of TSPO. Dynamic (1)H/(13)C NMR spectroscopy of 1a revealed four quite stable but interconverting rotamers, due to amide bond and 2-chlorophenyl group rotation. These rotamers have been neglected in previous descriptions of the structure of 1a and of the binding of 1a to TSPO. Here, we used quantum chemistry at the level of B3LYP/6-311+G(2d,p) to calculate (13)C and (1)H chemical shifts for the rotamers of 1a and for the very weak TSPO ligand, N-desmethyl-PK 11195 (1b). These data, plus experimental NMR data, were then used to characterize the structures of rotamers of 1a and 1b in organic solution. Energy barriers for both the amide bond and 2'-chlorophenyl group rotation of 1a were determined from dynamic (1)H NMR to be similar (ca.17 to 18 kcal/mol), and they compared well with those calculated at the level of B3LYP/6-31G*. Furthermore, the computed barrier for Z to E rotation is considerably lower in 1a(18.7 kcal/mol) than in 1b (25.4 kcal/mol). NMR (NOE) unequivocally demonstrated that the E rotamer of 1a is the more stable in solution by about 0.4 kcal/mol. These detailed structural findings will aid future TSPO ligand design and support the notion that TSPO prefers to bind ligands as amide E-rotamers.
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Ji JH, Shafi M, Lee YS, Kim DJ. Inferior paralabral ganglion cyst of the shoulder with labral tear -- a rare cause of shoulder pain. Orthop Traumatol Surg Res 2012; 98:193-8. [PMID: 22386705 DOI: 10.1016/j.otsr.2011.09.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2010] [Revised: 09/18/2011] [Accepted: 09/26/2011] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Paralabral ganglion cysts of the shoulder are rare, and their pathogenesis is similar to that of meniscal cysts. The paralabral cysts are most frequently reported along the posterior, superior, and anterior aspects of the glenohumeral joint and are uncommon inferiorly to the joint. These cysts rarely become evident clinically, unless they cause compression of surrounding structures, i.e. nerve. PATIENTS AND METHODS We report a retrospective series of five patients with inferior paralabral ganglion cysts of the shoulder without compression of the surrounding nerve which were treated during the period from March 2007 to December 2009. All these patients presented with only chronic shoulder pain as their chief complaint, and preoperative MRI showed the cyst over the inferior aspect of a torn glenoid labrum. All patients were treated by arthroscopic cystic decompression with labrum repair. All patients were re-evaluated with MRI performed at an average of 15 months postoperatively. The clinical outcome, including the Constant score, was assessed for all patients at a median of 16 months postoperatively. RESULTS All the five patients had remission of pain and were satisfied with the shoulder function. The postoperative MRI in all patients showed no labral cyst recurrence. The median Constant score improved from a preoperative level of 81.5 points to 98.0 points at last follow-up. CONCLUSION This study demonstrates that, in the absence of any nerve compression symptoms around the shoulder joint, inferior paralabral cysts with labral tear also be considered in the differential diagnosis of chronic shoulder pain. Arthroscopic repair of the cyst with repair of the labrum can lead to the disappearance of symptoms. Knowledge of this clinical condition and its imaging features is critical for a correct diagnosis of this uncommon cause of chronic shoulder pain. LEVEL OF EVIDENCE Level IV. Retrospective therapeutic study.
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Valla T, Pan ZH, Gardner D, Lee YS, Chu S. Photoemission spectroscopy of magnetic and nonmagnetic impurities on the surface of the Bi2Se3 topological insulator. PHYSICAL REVIEW LETTERS 2012; 108:117601. [PMID: 22540510 DOI: 10.1103/physrevlett.108.117601] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Indexed: 05/31/2023]
Abstract
Dirac-like surface states on surfaces of topological insulators have a chiral spin structure that suppresses backscattering and protects the coherence of these states in the presence of nonmagnetic scatterers. In contrast, magnetic scatterers should open the backscattering channel via the spin-flip processes and degrade the state's coherence. We present angle-resolved photoemission spectroscopy studies of the electronic structure and the scattering rates upon the adsorption of various magnetic and nonmagnetic impurities on the surface of Bi2Se3, a model topological insulator. We reveal a remarkable insensitivity of the topological surface state to both nonmagnetic and magnetic impurities in the low impurity concentration regime. Scattering channels open up with the emergence of hexagonal warping in the high-doping regime, irrespective of the impurity's magnetic moment.
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Lee YS, Tae K, Lee SH, Cho SH, Jeong JH, Min HJ, Ji YB. Change of telomerase activity in peripheral whole blood of head and neck squamous cell carcinoma patients before and after surgery: a pilot study. Clin Transl Oncol 2012; 13:747-53. [PMID: 21975338 DOI: 10.1007/s12094-011-0727-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The purpose of this study was to evaluate telomerase activity in peripheral whole blood from head and neck squamous cell carcinoma (HNSCC) patients as a biomarker for diagnosis of HNSCC or detection of recurrence during follow-up. MATERIALS AND METHODS Telomerase activity was measured from peripheral whole blood extracts by telomerase repeat amplification protocol (TRAP) in HNSCC patients before and after surgery and in a control group. Sixty-two HNSCC patients and 42 control subjects were included. RESULTS Telomerase activity was found in 41 out of 62 (66.1%) HNSCC patients before surgery and in 8 out of 42 (19.0%) controls (p<0.001). Among 41 HNSCC patients who showed positive telomerase activity before surgery, 32 (78.1%) showed a conversion of telomerase activity to negative after surgery. In follow-up, 6 out of 8 (75%) showed conversion of telomerase activity from negative to positive after recurrence. Telomerase activity was changed to negative in 4 out of 6 (66%) recurred patients with positive telomerase activity after second surgery. CONCLUSION The telomerase activity in peripheral whole blood extracts of HNSCC patients might be a useful biomarker for detecting recurrence after treatment. Further study with larger sample size using a more sensitive detection method of telomerase activity is necessary to verify these results.
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Kwon JH, Jang JW, Lee S, Lee J, Chung KW, Lee YS, Choi JY. Pretreatment HBeAg level and an early decrease in HBeAg level predict virologic response to entecavir treatment for HBeAg-positive chronic hepatitis B. J Viral Hepat 2012; 19:e41-7. [PMID: 22239525 DOI: 10.1111/j.1365-2893.2011.01509.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There are few reports on hepatitis B e antigen (HBeAg) titres during nucleos(t)ide analogues treatment. We investigated the changes in HBeAg levels in patients treated with entecavir and the usefulness of HBeAg quantification for predicting antiviral response. Ninety-five consecutive HBeAg-positive patients treated with entecavir for more than 48 weeks were enrolled. Serum levels of hepatitis B surface antigen (HBsAg), HBeAg and HBV DNA were assessed at 4-week intervals to week 24 and thereafter at 12-week intervals. Virologic response (Y1VR) was defined as an undetectable HBV DNA level at week 48 of therapy. During 48 weeks, HBeAg and HBV DNA level decreased significantly in a biphasic manner and HBsAg level tended to decease. Fifty-three patients (55.8%) attained Y1VR. Pretreatment HBeAg levels were significantly lower in the Y1VR group than in no Y1VR group. At week 4 and 12 of therapy, 25% and 41.4% of patients showed a decrease of HBeAg levels with >0.5 log(10) and >1.0 log(10) from baseline, respectively. These patients achieved more Y1VR than those with less decrease of HBeAg levels (97.7%vs 22.2% and 86.2%vs 29.3%, respectively). HBeAg level at week 12 had higher predictive values for Y1VR than HBV DNA level. Multivariate analysis revealed that a pretreatment HBeAg level of <360 PEIU/mL and the reduction in HBeAg level >1.0 log(10) at week 12 were associated with Y1VR. These results suggest that pretreatment HBeAg level and an early decrease in HBeAg level are useful measurements for predicting one-year virologic response during entecavir treatment.
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Wang YH, Hsieh D, Pilon D, Fu L, Gardner DR, Lee YS, Gedik N. Observation of a warped helical spin texture in Bi2Se3 from circular dichroism angle-resolved photoemission spectroscopy. PHYSICAL REVIEW LETTERS 2011; 107:207602. [PMID: 22181776 DOI: 10.1103/physrevlett.107.207602] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Indexed: 05/31/2023]
Abstract
A differential coupling of topological surface states to left- versus right-circularly polarized light is the basis of many optospintronics applications of topological insulators. Here we report direct evidence of circular dichroism from the surface states of Bi(2)Se(3) using laser-based time-of-flight angle-resolved photoemission spectroscopy. By employing a novel sample rotational analysis, we resolve unusual modulations in the circular dichroism photoemission pattern as a function of both energy and momentum, which perfectly mimic the predicted but hitherto unobserved three-dimensional warped spin texture of the surface states. By developing a microscopic theory of photoemission from topological surface states, we show that this correlation is a natural consequence of spin-orbit coupling. These results suggest that our technique may be a powerful probe of the spin texture of spin-orbit coupled materials in general.
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