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Zihajehzadeh S, Loh D, Lee M, Hoskinson R, Park EJ. A cascaded two-step Kalman filter for estimation of human body segment orientation using MEMS-IMU. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:6270-3. [PMID: 25571430 DOI: 10.1109/embc.2014.6945062] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Orientation of human body segments is an important quantity in many biomechanical analyses. To get robust and drift-free 3-D orientation, raw data from miniature body worn MEMS-based inertial measurement units (IMU) should be blended in a Kalman filter. Aiming at less computational cost, this work presents a novel cascaded two-step Kalman filter orientation estimation algorithm. Tilt angles are estimated in the first step of the proposed cascaded Kalman filter. The estimated tilt angles are passed to the second step of the filter for yaw angle calculation. The orientation results are benchmarked against the ones from a highly accurate tactical grade IMU. Experimental results reveal that the proposed algorithm provides robust orientation estimation in both kinematically and magnetically disturbed conditions.
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Ha JM, Yoon JH, Cho EB, Park GH, Park EJ, Kim KH, Kim KJ. Subungual desmoplastic malignant melanoma. J Eur Acad Dermatol Venereol 2014; 30:360-2. [PMID: 25307258 DOI: 10.1111/jdv.12777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Jang JY, Kim TY, Sohn JH, Lee TH, Jeong SW, Park EJ, Lee SH, Kim SG, Kim YS, Kim HS, Kim BS. Relative adrenal insufficiency in chronic liver disease: its prevalence and effects on long-term mortality. Aliment Pharmacol Ther 2014; 40:819-26. [PMID: 25078874 DOI: 10.1111/apt.12891] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 04/29/2014] [Accepted: 07/07/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND The relationship between relative adrenal insufficiency (RAI) and chronic liver disease is unclear. AIM To determine the frequency with which RAI is observed in noncritically ill patients at various stages of chronic liver disease, and the correlation between RAI and disease severity and long-term mortality. METHODS In total, 71 non-critically ill patients with liver cirrhosis (n = 54) and chronic hepatitis (n = 17) were evaluated prospectively. A short stimulation test (SST) with 250 μg of corticotrophin was performed to detect RAI. RAI was defined as an increase in serum cortisol of <9 μg/dL in patients with a basal total cortisol of <35 μg/dL. RESULTS RAI was observed in only 13 (24.1%) of 54 patients with cirrhosis. Compared to those without RAI, cirrhotic patients with RAI had significantly higher Child-Turcotte-Pugh score (10.3 ± 1.7 vs. 7.1 ± 1.8, mean ± s.d., P < 0.001) and Model for End-Stage Liver Disease score (14.5 ± 6.6 vs. 9.4 ± 3.7, P = 0.017). The cortisol response to corticotropin was negatively correlated with the severity of cirrhosis (P < 0.05). In addition, the mortality rate was higher in cirrhotic patients with RAI (69.2%) than in those without RAI (4.9%; P < 0.001) during the follow-up period of 20.1 ± 13.5 months (range, 5.8-51.1 months). The cumulative 1-year survival rates in cirrhotic patients with and without RAI were 69.2% and 95.0%, respectively (P = 0.05), while the corresponding cumulative 3-year survival rates were 0% and 95.0% (P < 0.001). CONCLUSIONS Relative adrenal insufficiency is more commonly observed in those with severe cirrhosis, and is clearly associated with more advanced liver disease and a shortened long-term survival. This suggests that relative adrenal insufficiency is an independent prognostic factor in non-critically ill patients with cirrhosis.
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Ku SH, Cho EB, Park EJ, Kim KH, Kim KJ. Dermoscopic features of molluscum contagiosum based on white structures and their correlation with histopathological findings. Clin Exp Dermatol 2014; 40:208-10. [PMID: 25252138 DOI: 10.1111/ced.12444] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2014] [Indexed: 11/30/2022]
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Park EJ, Min KJ, Lee TJ, Yoo YH, Kim YS, Kwon TK. β-Lapachone induces programmed necrosis through the RIP1-PARP-AIF-dependent pathway in human hepatocellular carcinoma SK-Hep1 cells. Cell Death Dis 2014; 5:e1230. [PMID: 24832602 PMCID: PMC4047891 DOI: 10.1038/cddis.2014.202] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 04/01/2014] [Accepted: 04/08/2014] [Indexed: 12/13/2022]
Abstract
β-Lapachone activates multiple cell death mechanisms including apoptosis, autophagy and necrotic cell death in cancer cells. In this study, we investigated β-lapachone-induced cell death and the underlying mechanisms in human hepatocellular carcinoma SK-Hep1 cells. β-Lapachone markedly induced cell death without caspase activation. β-Lapachone increased PI uptake and HMGB-1 release to extracellular space, which are markers of necrotic cell death. Necrostatin-1 (a RIP1 kinase inhibitor) markedly inhibited β-lapachone-induced cell death and HMGB-1 release. In addition, β-lapachone activated poly (ADP-ribosyl) polymerase-1(PARP-1) and promoted AIF release, and DPQ (a PARP-1 specific inhibitor) or AIF siRNA blocked β-lapachone-induced cell death. Furthermore, necrostatin-1 blocked PARP-1 activation and cytosolic AIF translocation. We also found that β-lapachone-induced reactive oxygen species (ROS) production has an important role in the activation of the RIP1-PARP1-AIF pathway. Finally, β-lapachone-induced cell death was inhibited by dicoumarol (a NQO-1 inhibitor), and NQO1 expression was correlated with sensitivity to β-lapachone. Taken together, our results demonstrate that β-lapachone induces programmed necrosis through the NQO1-dependent ROS-mediated RIP1-PARP1-AIF pathway.
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Lee KN, Ben-Nakhi M, Park EJ, Hong JP. Cyclic negative pressure wound therapy: an alternative mode to intermittent system. Int Wound J 2013; 12:686-92. [PMID: 24373578 DOI: 10.1111/iwj.12201] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 11/13/2013] [Accepted: 11/20/2013] [Indexed: 10/25/2022] Open
Abstract
The purpose of this study was to develop and test a novel mode of negative pressure wound therapy (NPWT) that minimises pain while preserving the efficacy in wound healing. A porcine model was used in this study. Wounds were generated in animals and treated with either simple dressing or various treatment modes of NPWT. The wound volume, perfusion level and vasculature status were analysed and compared among different groups. Clinical application was performed to evaluate the level of pain occurring when negative pressure is applied. Among the NPWT groups, the Cyclic-50 group showed most decrement in wound volume, even though statistical relevance was not found (P = 0·302). The perfusion level was significantly increased in the Cyclic-50 group compared with the Intermittent group (P < 0·001) and the Cyclic-100 group (P = 0·004). Evaluation of blood vessel formation revealed that the Cyclic-50 group showed the highest number of vasculature with statistical significance (P < 0·001). In clinical application, the cyclic group showed significant decrease in pain compared with the intermittent group (P = 0·001). The cyclic NPWT mode decreased patient discomfort while maintaining superior wound healing effects as the intermittent mode.
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Kim GA, Oh HJ, Park JE, Kim MJ, Park EJ, Jo YK, Jang G, Kim MK, Kim HJ, Lee BC. Species-specific challenges in dog cloning. Reprod Domest Anim 2013; 47 Suppl 6:80-3. [PMID: 23279471 DOI: 10.1111/rda.12035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 07/06/2012] [Indexed: 11/28/2022]
Abstract
Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning.
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Park S, Hong KEM, Park EJ, Ha KS, Yoo HJ. The association between problematic internet use and depression, suicidal ideation and bipolar disorder symptoms in Korean adolescents. Aust N Z J Psychiatry 2013; 47:153-9. [PMID: 23047959 DOI: 10.1177/0004867412463613] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE This study used a sample of Korean adolescents to evaluate: (a) associations between problematic internet use and depression, bipolar disorder symptoms and suicidal ideation; and (b) whether mood disorders mediate the relationship between problematic internet use and suicidal ideation. METHOD A total of 795 middle and high school students were recruited (538 girls; mean age, 13.87 ± 1.51 years). The Internet Addiction Proneness Scale for Youth-Short Form (KS-scale) was used to evaluate the presence and severity of problematic internet use. The frequencies of depression, suicidal ideation and probable bipolar disorder were compared between adolescents with and without internet addiction. The associations between the severity of problematic internet use and the severity of depressive symptoms, bipolar symptoms and suicidal ideation were also analyzed. RESULTS Seventy-five adolescents (9.4%) met the criteria for problematic internet use. The presence of problematic internet use was significantly associated with suicidal ideation (OR = 5.82, 95% CI = 3.30-10.26, p < 0.001) as well as depression (OR = 5.00, 95% CI = 2.88-8.66, p < 0.001). There was a marginally significant association between problematic internet use and probable bipolar disorder (OR = 3.05, 95% CI = 0.96-9.69, p = 0.059). In the path model, problematic internet use significantly predicted depressive symptoms (β = 0.296, 95% CI = 0.214-0.367, p = 0.005), which predicted suicidal ideation (β = 0.699, 95% CI = 0.631-0.751, p = 0.009). Problematic internet use also predicted suicidal ideation directly (β = 0.115, 95% CI = 0.052-0.193, p = 0.006). Conversely, depressive symptoms (β = 0.119, 95% CI = -0.005-0.219, p = 0.040) and suicidal ideation (β = 0.215, 95% CI = 0.089-0.346, p = 0.005) predicted problematic internet use. CONCLUSIONS There is a complex transactional relationship between problematic internet use, depressive symptoms, bipolar symptoms and suicidal ideation, so these conditions must be assessed together during the evaluation of adolescents. Prospective studies are warranted to elucidate the causal relationships between problematic internet use, mood symptoms and suicidal ideation.
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Cho SC, Hong YC, Kim JW, Park S, Park MH, Hur J, Park EJ, Hong SB, Lee JH, Shin MS, Kim BN, Yoo HJ, Cho IH, Bhang SY, Hahn S. Association between urine cotinine levels, continuous performance test variables, and attention deficit hyperactivity disorder and learning disability symptoms in school-aged children. Psychol Med 2013; 43:209-219. [PMID: 22608159 DOI: 10.1017/s0033291712001109] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND We examined the cross-sectional relationship between environmental tobacco smoke exposure, continuous performance test (CPT) measures, and attention deficit hyperactivity disorder (ADHD) or learning disability symptoms in school-aged children. METHOD In total, 989 children (526 boys, mean age 9.1 ± 0.7 years), recruited from five South Korean cities participated in this study. We used urine cotinine as a biomarker for environmental tobacco smoke exposure, and obtained the children's scores on a CPT. Parents completed the Korean versions of the ADHD rating scale-IV (ADHD-RS) and learning disability evaluation scale (LDES). Using generalized linear mixed model (GLMM), we assessed the associations between urine cotinine concentrations, neuropsychological variables, and symptoms of ADHD and learning disabilities. Additionally, we conducted structural equation models to explore the effects' pathways. RESULTS After adjusting for a range of relevant covariates, GLMM showed urinary cotinine levels were significantly and positively associated with CPT scores on omission errors, commission errors, response time, and response time variability, and with parent- and teacher-rated ADHD-RS scores. In addition, urine cotinine levels were negatively associated with LDES scores on spelling and mathematical calculations. The structural equation model revealed that CPT variables mediated the association between urine cotinine levels and parental reports of symptoms of ADHD and learning disabilities. CONCLUSIONS Our data indicate that environmental exposure to tobacco smoke is associated with ADHD and learning disabilities in children, and that impairments in attention and inhibitory control probably mediate the effect.
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Oh HJ, Park EJ, Lee SY, Soh JW, Kong IS, Choi SW, Ra JC, Kang SK, Lee BC. Comparison of cell proliferation and epigenetic modification of gene expression patterns in canine foetal fibroblasts and adipose tissue-derived mesenchymal stem cells. Cell Prolif 2012; 45:438-44. [PMID: 22925503 DOI: 10.1111/j.1365-2184.2012.00838.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES This study compared rate of cell proliferation, viability, cell size, expression patterns of genes related to pluripotency and epigenetic modification between canine foetal fibroblasts (cFF) and canine adipose tissue-derived mesenchymal stem cells (cAd-MSC). MATERIALS AND METHODS Proliferation pattern, cell viability as well as cell size at each passage of cFF and cAd-MSC were measured when cultures reached confluence. In addition, real-time PCR was performed to investigate expression of Dnmt1, HDAC1, OCT4, SOX2, BAX, BCL2 genes with reference to β-actin gene expression as an endogenous control in both cell lines. RESULTS cFF and cAd-MSC differed in number of generations, but not in doubling times, at all passages. Mean cell size of cAd-MSC was significantly smaller than that of cFF. Cell viability was significantly lower in cFFs and apoptotic level was significantly lower in cAd-MSC compared to passage-matched cFF. In the expression of genes related to pluripotency and epigenetic modification, level of HDAC1 in cAd-MSC was significantly higher than in cFF, but expression of Dnmt1 did not differ between the two groups. OCT4 and SOX2 were significantly more highly expressed in cAd-MSC compared to cFF. CONCLUSIONS cAd-MSC have higher stem-cell potential than cFF in terms of proliferation patterns, epigenetic modification and pluripotency, thus cAd-MSC could be more appropriate than cFF as donors of nuclei in somatic cell nuclear transfer for transgenesis.
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Lee KK, Cho JJ, Park EJ, Choi JD. Anti-elastase and anti-hyaluronidase of phenolic substance from Areca catechu as a new anti-ageing agent. Int J Cosmet Sci 2012; 23:341-6. [PMID: 18498484 DOI: 10.1046/j.0412-5463.2001.00102.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have previously screened 150 medicinal plants for the inhibition of elastase and found significant inhibitory effects of the extracts of Areca catechu L. on the ageing and inflammation of skin tissues. To isolate and identify the compounds having biological activity, they were further purified by each fraction of solvents, silica gel column chromatography, preparative TLC and reversed-phase HPLC. The peak in HPLC, which coincided with the inhibitory activity against elastase, was identified as a phenolic substance by using various colorimetric methods, UV and IR. IC(50) values of this phenolic substance were 26.9 mug mL(-1) for porcine pancreatic elastase (PPE) and 60.8 mug mL(-1) for human neutrophil elastase (HNE). This phenolic substance showed more potent activity than that of reference compounds, oleanolic acid (76.5 mug mL(-1) for PPE, 219.2 mug mL(-1) for HNE) and ursolic acid (31.0 mug mL(-1) for PPE, 118.6 mug mL(-1) for HNE). According to the Lineweaver-Burk plots, the inhibition against both PPE and HNE by this phenolic substance was competitive inhibition with the substrate. The phenolic substance from A. catechu effectively inhibited hyaluronidase activity (IC(50) : 210 mug mL(-1) ). These results suggest that the phenolic substance purified from A. catechu has an anti-ageing effect by protecting connective tissue proteins.
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Min KJ, Kim HS, Park EJ, Kwon TK. Melatonin enhances thapsigargin-induced apoptosis through reactive oxygen species-mediated upregulation of CCAAT-enhancer-binding protein homologous protein in human renal cancer cells. J Pineal Res 2012; 53:99-106. [PMID: 22289049 DOI: 10.1111/j.1600-079x.2012.00975.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) has differentiated the effects on apoptosis in normal and cancer cells. The mechanisms that account for the opposite effects on these cells are not adequately understood. In this study, we investigated the combined effect of melatonin and thapsigargin (TG) on apoptosis of renal cancer cells. Cotreatment with melatonin (1mm) and TG (50nm) induced approximately 10-fold expression levels of CCAAT-enhancer-binding proteins homologous protein (CHOP) compared with that of TG (50nm) alone. Downregulation of CHOP expression using small interfering RNAs markedly attenuated melatonin plus TG-mediated apoptosis. In addition, cotreatment with TG- and melatonin-induced CHOP upregulation likely relates to melatonin's antioxidant capacity because we proved that this CHOP upregulation is melatonin receptor independent. Our results collectively demonstrate that the upregulation of CHOP contributes to the enhancing effect of melatonin plus TG on apoptosis in cancer cells.
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Kim MJ, Oh HJ, Kim GA, Park JE, Park EJ, Jang G, Ra JC, Kang SK, Lee BC. Lessons Learned from Cloning Dogs. Reprod Domest Anim 2012; 47 Suppl 4:115-9. [DOI: 10.1111/j.1439-0531.2012.02064.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Andrade CS, Otaduy MCG, Valente KDR, Maia DF, Park EJ, Valério RMF, Tsunemi MH, Leite CC. Phosphorus magnetic resonance spectroscopy in malformations of cortical development. Epilepsia 2011; 52:2276-84. [PMID: 21973076 DOI: 10.1111/j.1528-1167.2011.03281.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE The aim of this study was to evaluate phospholipid metabolism in patients with malformations of cortical development (MCDs). METHODS Thirty-seven patients with MCDs and 31 control subjects were studied using three-dimensional phosphorus magnetic resonance spectroscopy ((31)P-MRS) at 3.0 T. The voxels in the lesions and in the frontoparietal cortex of the control subjects were compared (the effective volumes were 12.5 cm(3)). Robust quantification methods were applied to fit the time-domain data to the following resonances: phosphoethanolamine (PE); phosphocholine (PC); inorganic phosphate (Pi); glycerophosphoethanolamine (GPE); glycerophosphocholine (GPC); phosphocreatine (PCr); and α-, β-, and γ-adenosine triphosphate (ATP). We also estimated the total ATP (ATP(t) = α-+β-+γ-ATP), phosphodiesters (PDE = GPC+GPE), phosphomonoesters (PME = PE+PC), and the PME/PDE, PCr/ATP(t) and PCr/Pi ratios. The magnesium (Mg(2+)) levels and pH values were calculated based on PCr, Pi, and β-ATP chemical shifts. KEY FINDINGS Compared to controls and assuming that a p-value < 0.05 indicates statistical significance, the patients with MCDs exhibited significantly lower pH values and higher Mg(2+) levels. In addition, the patients with MCDs had lower GPC and PDE and an increased PME/PDE ratio. SIGNIFICANCE Mg(2+) and pH are important in the regulation of bioenergetics and are involved in many electrical activity pathways in the brain. Our data support the idea that neurometabolic impairments occur during seizure onset and propagation. The GPC, PDE, and PME/PDE abnormalities also demonstrate that there are membrane turnover disturbances in patients with MCDs.
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Park EJ, Koh HK, Kwon JW, Suh MK, Kim H, Cho SI. Secular trends in adult male smoking from 1992 to 2006 in South Korea: age-specific changes with evolving tobacco-control policies. Public Health 2009; 123:657-64. [PMID: 19892378 DOI: 10.1016/j.puhe.2009.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 08/22/2009] [Accepted: 09/15/2009] [Indexed: 11/16/2022]
Abstract
OBJECTIVES For years, South Korea has had one of the highest levels of tobacco use among males in the world, but a steady decline has been observed recently. This study examined how the smoking behaviour of male adults changed with age after the implementation of national tobacco control policies in 1995. STUDY DESIGN Repeated cross-sectional study using a national survey. METHODS Data were obtained from the 1992, 1995, 1999, 2003 and 2006 results of a repeated cross-sectional survey, the Social Statistics Survey. The smoking status of adult men was compared before (1992 and 1995 surveys) and after (1999, 2003 and 2006 surveys) the implementation of government-directed tobacco control policies using graphical methods and logistic regression analysis. RESULTS After the implementation of tobacco control policies, the percentage of current male smokers decreased while the percentage of former smokers increased markedly. Smoking prevalence among older men (aged 50 years or more) reduced initially, and this decline was more pronounced after the tobacco control policies were implemented. Smoking prevalence in younger men (aged 30-49 years) declined in 2003 when more comprehensive tobacco control policies were implemented. CONCLUSIONS This study suggests that comprehensive tobacco control policies in South Korea reduced smoking prevalence among males, initially among older men and later among both older men and younger men.
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Plum SM, Park EJ, Strawn SJ, Moore EG, Sidor CF, Fogler WE. Disease modifying and antiangiogenic activity of 2-methoxyestradiol in a murine model of rheumatoid arthritis. BMC Musculoskelet Disord 2009; 10:46. [PMID: 19409094 PMCID: PMC2687416 DOI: 10.1186/1471-2474-10-46] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 05/01/2009] [Indexed: 11/23/2022] Open
Abstract
Background A critical component of disease progression in rheumatoid arthritis (RA) involves neovascularization associated with pannus formation. 2-methoxyestradiol (2ME2) is a naturally occurring molecule with no known physiologic function, although at pharmacologic concentrations it has antiproliferative and antiangiogenic activities. We investigated the impact of orally administered 2ME2 on the initiation and development of proliferative synovitis using the anti-collagen monoclonal antibodies (CAIA) model. Methods Severe polyarticular arthritis was induced in Balb/c female mice by administration of 2 mg of a monoclonal antibody cocktail intravenously into the tail vein of mice. Twenty-four hours following monoclonal antibody administration, mice were injected with 25 μg of LPS (E. coli strain 0111:B4) via the intraperitoneal route. Treatment with 2ME2 (100, 75, 50, 25, 10, 1 mg/kg, p.o., daily), or vehicle control began 24 hrs following LPS challenge and continued to day 21. Hind limbs were harvested, sectioned and evaluated for DMARD activity and general histopathology by histomorphometric analysis and immunohistochemistry (vWF staining). In a separate study, different dosing regimens of 2ME2 (100 mg/kg; q.d. vs q.w. vs q.w. × 2) were evaluated. The effect of treatment with 2ME2 on gene expression of inflammatory cytokines and angiogenic growth factors in the joint space was evaluated 5 and 14 days after the induction of arthritis. Results Mice treated with 2ME2 beginning 24 hours post anti-collagen monoclonal antibody injection, showed a dose-dependent inhibition in mean arthritic scores. At study termination (day 21), blinded histomorphometric assessments of sectioned hind limbs demonstrated decreases in synovial inflammation, articular cartilage degradation, pannus formation, osteoclast activity and bone resorption. At the maximal efficacious dosing regimen (100 mg/kg/day), administration of 2ME2 resulted in total inhibition of the study parameters and prevented neovascularization into the joint. Examination of gene expression on dissected hind limbs from mice treated for 5 or 14 days with 2ME2 showed inhibition of inflammatory cytokine message for IL-1β, TNF-α, IL-6 and IL-17, as well as the angiogenic cytokines, VEGF and FGF-2. Conclusion These data demonstrate that in the CAIA mouse model of RA, 2ME2 has disease modifying activity that is at least partially attributable to the inhibition of neovascular development. Further, the data suggests new mechanistic points of intervention for 2ME2 in RA, specifically inhibition of inflammatory mediators and osteoclast activity.
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Liu W, Dechev N, Lee SW, Foulds IG, Parameswaran A, Burke R, Park EJ. Development of a magnetic Single Cell Micro Array. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:3170-3. [PMID: 19163380 DOI: 10.1109/iembs.2008.4649877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Experiments using single cells are valuable for revealing individual cell behaviour, which is of interest to many biomedical researchers. In such experiments, various types of devices capable of aligning cells into organized arrays are often used. In this paper, we present a novel Single Cell Micro Array device that makes use of magnetic forces. Prototypes of this device have been fabricated, and successfully tested using Jurkat cells that have been labelled with nano-magnetic particles. Experimental results show that the prototypes are effective on capturing and placing the labelled cells in an array.
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Birch B, Haslam E, Heerah I, Dechev N, Park EJ. Design of a continuous passive and active motion device for hand rehabilitation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:4306-9. [PMID: 19163665 DOI: 10.1109/iembs.2008.4650162] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This paper presents the design of a novel, portable device for hand rehabilitation. The device provides for CPM (continuous passive motion) and CAM (continuous active motion) hand rehabilitation for patients recovering from damage such as flexor tendon repair and strokes. The device is capable of flexing/extending the MCP (metacarpophalangeal) and PIP (proximal interphalangeal) joints through a range of motion of 0 degrees to 90 degrees for both the joints independently. In this way, typical hand rehabilitation motions such as intrinsic plus, intrinsic minus, and a fist can be achieved without the need of any splints or attachments. The CPM mode is broken into two subgroups. The first mode is the use of preset waypoints for the device to cycle through. The second mode involves motion from a starting position to a final position, but senses the torque from the user during the cycle. Therefore the user can control the ROM by resisting when they are at the end of the desired motion. During the CPM modes the device utilizes a minimum jerk trajectory model under PD control, moving smoothly and accurately between preselected positions. CAM is the final mode where the device will actively resist the movement of the user. The user moves from a start to end position while the device produces a torque to resist the motion. This active resistance motion is a unique ability designed to mimic the benefits of a human therapist. Another unique feature of the device is its ability to independently act on both the MCP and PIP joints. The feedback sensing built into the device makes it capable of offering a wide and flexible range of rehabilitation programs for the hand.
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Stegman KJ, Podhorodeski RP, Park EJ. A feasibility study for measuring accurate tendon displacements using an audio-based Fourier analysis of pulsed-wave Doppler ultrasound signals. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2009:1363-1366. [PMID: 19964755 DOI: 10.1109/iembs.2009.5334450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The accuracy of Pulsed-Wave Doppler Ultrasound displacement measurements of a slow moving "tendon-like" string was investigated in this study. This was accomplished by estimating string displacements using an audio-based Fourier analysis of a Pulsed-Wave Doppler signal from a commercial ultrasound scanner. Our feasibility study showed that the proposed technique is much more accurate at estimating the actual string displacement in comparison to the scanner's onboard software. Furthermore, this study also shows that a real-time Doppler data acquisition from an ultrasound scanner is possible for the ultimate purpose of real-time biological tendon displacement monitoring.
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Lee HS, Ji HY, Park EJ, Kim SY. In vitrometabolism of eupatilin by multiple cytochrome P450 and UDP-glucuronosyltransferase enzymes. Xenobiotica 2008; 37:803-17. [PMID: 17701830 DOI: 10.1080/00498250701534877] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Eupatilin, a pharmacologically active flavone derived from Artemisia plants, is extensively metabolized to eupatilin glucuronide, 4-O-desmethyleupatilin and 4-O-desmethyleupatilin glucuronide in human liver microsomes. This study characterized the human liver cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes responsible for the metabolism of eupatilin. The specific CYPs responsible for O-demethylation of eupatilin to the major metabolite, 4-O-desmethyleupatilin were identified using a combination of correlation analysis, immuno-inhibition, chemical inhibition in human liver microsomes and metabolism by human cDNA-expressed CYP enzymes. UGT enzymes involved in the eupatilin glucuronidation were identified using pooled human liver microsomes and human cDNA-expressed UGT enzymes. Eupatilin was predominantly metabolized by CYP1A2 and, to a lesser extent, CYP2C8 mediated O-demethylation of eupatilin to 4-O-desmethyleupatilin. Eupatilin glucuronidation was catalysed by UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A9, and UGT1A10.
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Park EJ, Alexander E, Taylor GA, Costa R, Kang DH. Effect of electrolyzed water for reduction of foodborne pathogens on lettuce and spinach. J Food Sci 2008; 73:M268-72. [PMID: 19241556 DOI: 10.1111/j.1750-3841.2008.00809.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ability of electrolyzed water (EW) to inactivate foodborne pathogens on the surfaces of lettuce and spinach was investigated. Lettuce and spinach leaves were inoculated with a cocktail of 3 strains each of Escherichia col O157:H7, Salmnonella Typhimurium, and Listeria monocytogenes and treated with acidic electrolyzed water (AC-EW), alkaline electrolyzed water (AK-EW), alkaline electrolyzed water followed by acidic electrolyzed water (sequential treatment, AK-EW + AC-EW), deionized water followed by acidic electrolyzed water (sequential treatment, DW + AC-EW), and deionized water (control, DW) for 15, 30 s, and 1, 3, and 5 min at room temperature (22 +/- 2 degrees C). For all 3 pathogens, the same pattern of microbial reduction on lettuce and spinach were apparent. The relative efficacy of reduction was AC-EW > DW + AC-EW approximately = AK-EW + AC-EW > AK-EW > control. After a 3-min treatment of AC-EW, the 3 tested pathogens were reduced below the detection limit (0.7 log). DW + AC-EW and AK-EW + AC-EW produced the same levels of reduction after 5 min when compared to the control. AK-EW did not reduce levels of pathogens even after a 5-min treatment on lettuce and spinach. Results suggest that AC-EW treatment was able to significantly reduce populations of the 3 tested pathogens from the surfaces of lettuce and spinach with increasing time of exposure.
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Li Y, Park EJ, Lim KT, Johnston KP, Green PF. Role of interfacial interactions on the anomalous swelling of polymer thin films in supercritical carbon dioxide. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/polb.21159] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Park EJ, Werner J, Smith NB. Ultrasound mediated transdermal insulin delivery in pigs using a lightweight transducer. Pharm Res 2007; 24:1396-401. [PMID: 17443398 DOI: 10.1007/s11095-007-9306-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 03/26/2007] [Indexed: 10/23/2022]
Abstract
PURPOSE In previous studies, ultrasound mediated transdermal drug delivery has shown a promising potential as a method for noninvasive drug administration. For prospective future human application, this study was designed to determine the feasibility of lightweight cymbal transducer array as a practical device for noninvasive transdermal insulin delivery in large pigs. MATERIALS AND METHODS Six Yorkshire pigs (100-140 lbs) were divided into two groups. As the control (n = 3), the first group did not receive any ultrasound exposure with the insulin. The second group (n = 3) was treated with ultrasound and insulin at 20 kHz with an I(sptp) = 100 mW/cm(2) at a 20% duty cycle for 60 min. With the pigs in lateral recumbency after anesthesia, the ultrasound transducer with insulin was placed on the axillary area of the pig. At the beginning and every 15 min up to 90 min, the blood glucose level was determined using a glucose monitoring system. To compare the results of individual animals, the change of blood glucose level was normalized to each animal's initial glucose value at the start of the experiment. RESULTS Although each animal had a different initial glucose level, the mean and standard error for the six animals was 146 +/- 13 mg/dl. For the control group, the blood glucose level increased to 31 +/- 21 mg/dl compared to the initial baseline over the 90 min experiment. However for the ultrasound with insulin treated group, the glucose level decreased to -72 +/- 5 mg/dl at 60 min (p < 0.05) and continued to decrease to -91 +/- 23 mg/dl in 90 min (p < 0.05). CONCLUSION The results indicate the feasibility of ultrasound mediated transdermal insulin delivery using the cymbal transducer array in animal with a similar size and weight to a human. Based on these result, the cymbal array has potential as a practical ultrasound system for noninvasive transdermal insulin delivery for diabetes management.
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Leach WT, Simpson DT, Val TN, Yu Z, Lim KT, Park EJ, Williams RO, Johnston KP. Encapsulation of protein nanoparticles into uniform-sized microspheres formed in a spinning oil film. AAPS PharmSciTech 2005; 6:E605-17. [PMID: 16408862 PMCID: PMC2750608 DOI: 10.1208/pt060475] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Accepted: 09/14/2005] [Indexed: 11/30/2022] Open
Abstract
A new spinning oil film (SOF) solid-in-oil-in-oil emulsion process was developed to produce uniform-sized protein-loaded biodegradable microspheres. A thin SOF on a cylindrical rotor was used to shear droplets from a nozzle tip to control droplet size. The resulting microspheres with low polydispersity (6%) produced a low burst (6%-11%) release even at high loadings (13%-18% encapsulated solids, 8%-12% protein). The SOF process had a high yield and did not require the presence of water, which can cause protein denaturation, or surfactants, which may be unwanted in the final product. Amorphous protein and crystalline excipient solids were encapsulated into 3 different polymers, giving a homogenous drug distribution throughout the microspheres, and an essentially complete protein encapsulation efficiency (average = 99%). In contrast, large burst release was observed for polydisperse microspheres produced by a conventional emulsification technique, particularly for microspheres smaller than 25 mum in diameter, which gave 93% burst at 15% loading. The uniform encapsulation of high loadings of proteins into microspheres with low polydispersity in an anhydrous process is of practical interest in the development of controlled-release protein therapeutics.
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Lee SK, Lee HJ, Min HY, Park EJ, Lee KM, Ahn YH, Cho YJ, Pyee JH. Antibacterial and antifungal activity of pinosylvin, a constituent of pine. Fitoterapia 2005; 76:258-60. [PMID: 15752644 DOI: 10.1016/j.fitote.2004.12.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Accepted: 12/14/2004] [Indexed: 10/25/2022]
Abstract
The antibacterial and antifungal activities of pinosylvin (3,5-dihydroxy-trans-stilbene), a constituent of pine, were studied and compared with those of resveratrol (3,5,4'-trihydroxy-trans-stilbene). Pinosylvin exhibited more potent growth inhibitory activity against Candida albicans and Saccharomyces cerevisiae.
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