92 results on '"S.-S. Kwon"'
Search Results
2. The effect of vaccination with DNA encoding murine T-cell epitopes on the Der p 1 and 2 induced immunoglobulin E synthesis
- Author
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T.J. Yoo, Nachsung Kim, and S. S. Kwon
- Subjects
T-Lymphocytes ,Genetic enhancement ,Immunology ,Gene Expression ,Immunoglobulin E ,Epitope ,Epitopes ,Interferon-gamma ,Mice ,Plasmid ,Immune system ,Antigen ,Reference Values ,Animals ,Immunology and Allergy ,Antigens, Dermatophagoides ,Antigens ,Lung ,Gene ,Glycoproteins ,Mice, Inbred BALB C ,biology ,Vaccination ,DNA ,Immunohistochemistry ,Naked DNA ,Immunoglobulin G ,biology.protein - Abstract
Background: Immunization with naked plasmid DNA leads to strong and persistent cell-mediated and humoral immune response to plasmid encoded antigen. Vaccination of DNA encoded whole allergen has been tried, but little information is currently available on the efficacy of DNA encoding T-cell epitopes in allergic disease. The purpose of this study was to determine whether the vaccination of naked plasmid DNA encoding only T-cell epitopes suppresses the allergic reaction as effectively as naked DNA encoding whole segments of allergen. Methods: We immunized mice with a mixed naked plasmid DNA encoding the five classes of murine T-cell epitopes on Der p 1 and Der p 2 three times at weekly intervals via an intramuscular injection of BALB/c mice. Control mice were injected with the pcDNA 3.1 blank vector. After 3 weeks, the mice were actively sensitized twice and allowed to inhale the Der p extracts intranasally six times at weekly intervals. Results: The vaccinated mice showed a significant attenuated induction of Der p-specific immunoglobulin E synthesis compared to controls. In terms of the Der p-specific IgG2a antibody response, the vaccinated mice showed more prominent responses than the control mice group. In addition, analysis of the cytokine profile after Der p stimulation of the lymph-node cells revealed that the level of the mRNA expression of the interferon-γ gene was higher in the vaccinated mice than in the controls. Histologic studies showed a much reduced infiltration of inflammatory cells in lung tissue of the gene-vaccinated mice in comparison with the controls. Conclusions: These results suggest that vaccination with DNA encoding T-cell epitopes effectively inhibits allergen-induced IgE synthesis and reduces cell infiltration in lung tissue. Thus, gene therapy using T-cell epitope-encoding DNA presents an ideal way of combating allergic disease in the future.
- Published
- 2001
3. SEEDLING GROWTH AND FRUIT SET AND QUALITY OF CUCUMBER AS AFFECTED BY TRIAZOLE CHEMICALS
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S.-S. Kwon, E.-J. Bae, J.-M. Lee, and C.-W. Lee
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Fructification ,biology ,Myclobutanil ,Horticulture ,Phytopharmacology ,biology.organism_classification ,Plantlet ,Fungicide ,chemistry.chemical_compound ,Agronomy ,chemistry ,Seedling ,Chlorophyll ,Gibberellic acid - Abstract
Several triazole chemicals, sprayed onto cucumber seedlings at the first true leaf stage, were effective in slowing down the excessive outgrowth of seedlings and in increasing the chlorophyll content in the leaves, thus resulting in more compact and healthier seedlings. Fruit quality was not influenced by triazole chemicals even though the number of pistillate flowers was markedly affected by the kind of triazole chemicals used. Bitertanol at 1,000 ppm was found promising for producing steadier and healthier seedlings with more pistillate flowers per plant without influencing the fruit yield and quality.
- Published
- 1999
4. The association between the self-perception period of overactive bladder symptoms and overactive bladder symptom scores in a non-treated population and related sociodemographic and lifestyle factors
- Author
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J H, Kim, B K, Ham, S R, Shim, W J, Lee, H J, Kim, S-S, Kwon, and J H, Bae
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Adult ,Male ,Urinary Bladder, Overactive ,Middle Aged ,Self Concept ,Body Mass Index ,Age Distribution ,Cross-Sectional Studies ,Socioeconomic Factors ,Surveys and Questionnaires ,Republic of Korea ,Humans ,Regression Analysis ,Life Style ,Aged - Abstract
To investigate the association between the self-perception period of OAB symptoms (SP-OAB) and the overactive bladder symptom score (OABSS), along with related sociodemographic and lifestyle factors.This was a cross-sectional study comprised of 192 men aged 40 years and older who participated in a prostate examination survey between February and May 2009 and proved to have OAB. Survey questionnaires included items on the OABSS and the SP-OAB assessed by the OABSS. Various sociodemographic and lifestyle factors were also included.The average SP-OAB period was 24.72 ± 45.75 months and became significantly longer as the severity of OAB increased in correlation analysis (coefficient = 0.501, p0.001). Age, education, income, regular check-up, health maintenance and occupation were all risk factors in both OABSS and SP-OAB in univariate analysis. Body mass index (BMI), family size and SP-OAB were risk factors for OABSS in univariate analysis. Age and regular check-ups were factors in both OABSS and SP-OAB in multivariate analysis. BMI, income and SP-OAB were risk factors for OABSS.These findings suggest that the SP-OAB is an independent risk factor for OAB progression and that various sociodemographic and lifestyle factors affect OABSS. The self-perception period should be considered in the treatment and prevention of OAB symptoms.
- Published
- 2013
5. Treatment satisfaction with low-dose tamsulosin for symptomatic benign prostatic hyperplasia: results from a multicentre cross-sectional survey
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J H, Kim, J Y, Park, M M, Oh, J G, Lee, S-S, Kwon, and J H, Bae
- Subjects
Aged, 80 and over ,Male ,Tamsulosin ,Sulfonamides ,Prostatic Hyperplasia ,Urination ,Middle Aged ,Cross-Sectional Studies ,Treatment Outcome ,Lower Urinary Tract Symptoms ,Patient Satisfaction ,Adrenergic alpha-1 Receptor Antagonists ,Humans ,Aged - Abstract
To evaluate the efficacy and treatment satisfaction with low-dose (0.2 mg) tamsulosin in patients with symptomatic benign prostatic hyperplasia (BPH), and to investigate individual lower urinary tract symptoms according to treatment satisfaction.A cross-sectional study was conducted in a total sample of 2574 patients from multiple centres. International Prostate Symptom Score (IPSS), prostate volume, uroflowmetry and combined medications were reviewed. Detailed questionnaires were used to assess treatment satisfaction and IPSS 8 weeks after treatment with low-dose tamsulosin.After 8 weeks of treatment with low-dose tamsulosin, IPSS improved significantly. Among the 2574 patients, 1,630 (63.42%) were satisfied and 940 patients (36.50%) were dissatisfied with low-dose tamsulosin. The reasons for dissatisfaction included efficacy problems (84.66%) and side effects (3.72%). Treatment satisfaction was affected by symptom duration, baseline IPSS, and prostate size (p = 0.0441,0.001,0.009, respectively). IPSS voiding (IPSS-V) and IPSS storage (IPSS-S) after treatment differed significantly depending on the degree of satisfaction (p0.001). IPSS-V after treatment did not improve in patients who were 'not satisfied' or 'totally not satisfied' (p = 0.170, 0.240, respectively). All the individual IPSS items except urgency (p = 0.1436) varied significantly with the degree of satisfaction (p0.001).Treating symptomatic BPH with low-dose tamsulosin improved IPSS, but more than one-third of patients were dissatisfied with the treatment. The main reason for dissatisfaction was efficacy problems, and the degree of satisfaction was related to symptom duration, baseline IPSS, and prostate size, and also to IPSS-V. In patients with severe LUTS, the tamsulosin dose should be increased earlier.
- Published
- 2012
6. Sociodemographic and lifestyle factors affecting the self-perception period of lower urinary tract symptoms of international prostate symptom score items
- Author
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J H, Kim, S R, Shim, W J, Lee, H J, Kim, S-S, Kwon, and J H, Bae
- Subjects
Adult ,Male ,Cross-Sectional Studies ,Lower Urinary Tract Symptoms ,Socioeconomic Factors ,Prostatic Hyperplasia ,Humans ,Middle Aged ,Life Style ,Severity of Illness Index ,Self Concept ,Aged - Abstract
This study investigated the influence of sociodemographic and lifestyle factors on the lower urinary tract symptom (LUTS) self-perception period and International Prostate Symptom Score.This cross-sectional study examined 209 men aged ≥ 40 years with non-treated LUTS who participated in a prostate examination survey. Questions included International Prostate Symptom Score (IPSS) items with self-perception periods for each item. Sociodemographic and lifestyle factors were also assessed. Participants were divided by mild LUTS (IPSS less than 8) and moderate-to-severe LUTS (IPSS 8 or higher).Self-perception period of the moderate-to-severe LUTS (n = 110) was affected by BMI; the self-perception period of the mild LUTS (n = 90) was affected by age, income, occupation and concomitant disease. Moderate-to-severe LUTS were affected by self-perception period (p = 0.03). Self-perception period was affected by concern for health (p = 0.005) by multivariate analysis, and self-perception period of mild LUTS was affected by BMI (p = 0.012). Moderate-to-severe LUTS were affected by age, number of family members, concern for health and drinking (p0.05, respectively) by multivariate analysis.Lower urinary tract symptom was affected by self-perception period. In moderate-to-severe LUTS, age, concern for health and drinking were affecting factors of self-perception period.
- Published
- 2012
7. A New Circulation Model Combined With a Detailed Network Model of Arterial Blood Flow
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Y. T. Kim, E. B. Kim, and S. S. Kwon
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Physics ,Laplace transform ,Quantitative Biology::Tissues and Organs ,Physics::Medical Physics ,Arterial blood flow ,Blood flow ,Mechanics ,Dissipation ,medicine.anatomical_structure ,Continuity equation ,Ventricle ,medicine ,Atrium (heart) ,Simulation ,Network model - Abstract
This study developed a model of the entire cardiovascular system combined with a Laplace heart based on the numerical cardiac-cell model and a detailed arterial-network structure. Our model incorporates the Laplace heart model and pulmonary model using a lumped-parameter model with a distributed arterial-system model. The Laplace heart acts as a pump and consists of an atrium and ventricle. We applied a cellular-contraction model modulated by the calcium concentration and action potential in a single cell. The numerical arterial model is based on a numerical solution of the one-dimensional momentum equations and the continuity equation of flow and vessel wall motion in a geometrically accurate branching network of the arterial system that includes energy loss at bifurcations. To validate our method, the computed pressure waves were compared with existing experimental observations. Using the combined cell–system–arterial network model, pathophysiological events at levels from cells to the arterial network are delineated.Copyright © 2011 by KSME
- Published
- 2011
8. Molecular mechanism of autoimmune hearing loss
- Author
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X. Du, T.J. Yoo, and S. S. Kwon
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medicine.medical_specialty ,Hearing loss ,Hearing Loss, Sensorineural ,Autoantigens ,Autoimmune Diseases of the Nervous System ,Laminin ,Tubulin ,Internal medicine ,Heat shock protein ,otorhinolaryngologic diseases ,medicine ,Animals ,Humans ,Inner ear ,HSP70 Heat-Shock Proteins ,Meniere Disease ,Autoantibodies ,Autoimmune disease ,biology ,business.industry ,Antibodies, Monoclonal ,Proteins ,General Medicine ,medicine.disease ,Pathophysiology ,Cell biology ,Proto-Oncogene Proteins c-raf ,medicine.anatomical_structure ,Endocrinology ,Otorhinolaryngology ,Ear, Inner ,biology.protein ,sense organs ,Collagen ,medicine.symptom ,Antibody ,business ,Myelin P0 Protein - Abstract
Molecules considered as autoantigens in autoimmune sensorineural hearing loss and Me´nie ¤ re's diseases are type II collagens, type IX collagens, 30 kD proteins of inner ear membranes, laminin, 68 kD proteins of inner ear, PO protein, Raf I protein and g -tubulin are reviewed in relation to molecular mechanisms of autoimmune injury of inner ear resulting in hearing loss.
- Published
- 2002
9. MR imaging of solitary pulmonary lesion: emphasis on tuberculomas and comparison with tumors
- Author
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M H, Chung, H G, Lee, S S, Kwon, and S H, Park
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Male ,Lung Neoplasms ,Solitary Pulmonary Nodule ,Image Enhancement ,Magnetic Resonance Imaging ,Sensitivity and Specificity ,Diagnosis, Differential ,Humans ,Female ,Prospective Studies ,Tuberculoma ,Lung ,Tuberculosis, Pulmonary ,Probability - Abstract
The aim of this study was to determine whether solitary pulmonary tuberculoma and malignant tumor can be differentiated on the basis of magnetic resonance (MR) signal intensity. Twenty-eight patients with solitary pulmonary lesions were prospectively studied with MR imaging: T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted spin echo images were obtained. The confirmation methods used were computed tomography (CT)-guided biopsy in seven patients with lung cancer and four patients with tuberculosis; surgery in ten patients with lung cancer and five patients with tuberculosis; and laboratory data in two patients with tuberculosis. Morphologic features and MR signal intensity were examined in detail. As the test for detection of tuberculoma, signal difference on T2-weighted images was carefully analyzed. The signal intensity ratio of the nodule to thoracic muscle signal intensity was measured. The signal intensities obtained from the lung cancers and tuberculomas were variable on pre-and post-enhanced T1-weighted images and proton density-weighted images. Masses were hypointense in 2 of 17 patients with lung cancer and in 9 of 11 patients with tuberculoma on T2-weighted images (sensitivity 82%, specificity 89%, accuracy 87%). The mean signal intensity ratios of the tuberculomas to muscle were significantly lower than those of malignant tumors on T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted images (P0.0001). After gadolinium-DTPA enhancement, 2 malignant tumors and 7 tuberculomas showed a marginal rim enhancement pattern, whereas 15 malignant tumors and 2 tuberculomas revealed a diffuse enhancement. The results of MR imaging were consistent with those of CT in 84% of the patients. MR imaging is a helpful adjunctive method in terms of differentiating a tuberculoma from a malignant tumor.
- Published
- 2000
10. CONJUGATE NATURAL CONVECTION HEAT TRANSFER FROM A HORIZONTAL CYLINDER WITH A LONG VERTICAL LONGITUDINAL FIN
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S. S. Kwon and T. H. Kuehn
- Subjects
Numerical Analysis ,Materials science ,Fin ,Convective heat transfer ,General Engineering ,Thermodynamics ,Film temperature ,Heat transfer coefficient ,Rayleigh number ,Mechanics ,Condensed Matter Physics ,Annular fin ,Churchill–Bernstein equation ,Computer Science Applications ,Physics::Fluid Dynamics ,Mechanics of Materials ,Modeling and Simulation ,Heat transfer - Abstract
Conjugate heat transfer by steady laminar natural convection from an isothermal circular cylinder with one infinitely long vertical plate fin has been studied by a finite-difference numerical procedure. Interactions between the fin and cylinder boundary layers are determined through the elliptic nature of the solution technique. Heat transfer from both the fin and the cylinder is less than predicted, disregarding the complex interactions. A fin of low conductance reduces the total heat transfer below the free-cylinder value. Fins of large conductance enhance the total heat transfer by a few percent. Heat transfer correlations have been developed to predict local and total heat transfer rates for both the fin and the cylinder as a function of the three governing dimensionless parameters: Rayleigh number, Prandtl number, and fin conduction parameter.
- Published
- 1983
11. On Natural Convection From a Short Conducting Plate Fin Below a Heated Horizontal Cylinder
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A. K. Tolpadi, Thomas H. Kuehn, and S. S. Kwon
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Physics ,Natural convection ,Mechanics of Materials ,Mechanical Engineering ,Cylinder ,General Materials Science ,Mechanics ,Condensed Matter Physics ,Fin (extended surface) - Abstract
Analyse numerique et etude experimentale de l'influence de la longueur de l'ailette sur le transfert de chaleur stationnaire par convection naturelle d'un cylindre horizontal isotherme muni d'une ailette plane verticale longitudinale a sa partie inferieure
- Published
- 1984
12. Natural Convection in the Annulus Between Horizontal Circular Cylinders With Three Axial Spacers
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T. S. Lee, S. S. Kwon, and Thomas H. Kuehn
- Subjects
Convection ,Materials science ,Natural convection ,Mechanical Engineering ,Prandtl number ,Thermodynamics ,Rayleigh number ,Mechanics ,Condensed Matter Physics ,Thermal conduction ,Physics::Fluid Dynamics ,symbols.namesake ,Thermal conductivity ,Mechanics of Materials ,Heat transfer ,Annulus (firestop) ,symbols ,General Materials Science - Abstract
Conjugate natural convection heat transfer in an annulus between horizontal isothermal circular cylinders with three equally spaced axial spacers has been studied theoretically and experimentally. A thin-fin approximation was used to model the thermal boundary condition of the spacers in the two-dimensional finite difference numerical computations. Rayleigh number, Prandtl number, diameter ratio, and location and thermal conductivity of the spacers were varied parametrically to determine the variation in flow patterns, temperature distribution and heat transfer. Spacers of low conductivity can decrease the natural convection heat transfer by as much as 20 percent below that for a simple unobstructed annulus. However, radial conduction through spacers of high conductivity overwhelms the natural convection heat transfer between the cylinders. Two diameter ratios were tested experimentally in a Mach-Zehnder interferometer using air at atmospheric pressure with stainless steel spacers between copper cylinders. The numerical and experimental temperature distributions and local convective heat-transfer coefficients show good agreement.
- Published
- 1982
13. How Neighborhood Structural and Individual Characteristics Affect Frailty Progression: Evidence from the China Health and Retirement Longitudinal Study.
- Author
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Ge F and Kwon S
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- Aged, Humans, Male, Female, Longitudinal Studies, Frail Elderly, Prospective Studies, China epidemiology, Retirement, Frailty epidemiology
- Abstract
Objectives: (1) To characterize the average trajectories of frailty over time in Chinese community-dwelling older adults; (2) To assess the effects of neighborhood structural and individual characteristics on frailty progression., Design: A nationally representative prospective cohort study., Setting: Communities in 28 provinces, China., Participants: 6238 respondents aged 60 and above in 447 communities from four waves of the China Health and Retirement Longitudinal Study., Measurements: Frailty was measured using the 61-item Frailty Index (FI)., Results: The trajectory of FI was nonlinear, with an average growth rate of 0.025 that significantly slows down at the rate of 0.002 per year. Older, male, and uninsured respondents showed faster rates of growth in FI over time than younger, female, and insured counterparts. Respondents living in neighborhoods with a higher percentage of the older population and rural villages showed slower rates of growth in FI over time., Conclusion: Expanding health insurance coverage and keeping a high clustering of the elderly in neighborhoods may be the potential strategies for population-level frailty prevention and interventions., Competing Interests: The authors declare no conflicts of interests.
- Published
- 2023
- Full Text
- View/download PDF
14. Feasibility Study for an Automated Engineering Change Process.
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Sharp ME, Hedberg TD Jr, Bernstein WZ, and Kwon S
- Abstract
Engineering change is a significant cost sink in many projects. While avoiding and mitigating the risk of change is the ideal approach, mistakes and improvements are recognized inevitably as more is learned over time about the quality of the decisions made in a product's design. This paper presents a feasibility and performance analysis of automating engineering change requests to demonstrate the promise for increasing speed, efficiency, and effectiveness of product-lifecycle-wide engineering-change-request processes. To explore this idea, a comparatively simple case study is examined both to mimic the reduced set of alterable aspects of a typical change request and to highlight the need of appropriate search algorithms as brute force methods quickly prohibitively resource intensive. Although such cases may seem trivial for human agents, with the volume of expected change requests in a typical facility, the potential opportunity gain by eliminating or reducing the amount of human effort in low level change requests accumulate into significant returns for industry on time and money. Within this work, the genetic algorithm is selected to demonstrate feasibility due to its broad scope of applicability and low barriers to deployment. Future refinement of this or other sophisticated algorithms leveraging the nature of the standard representations and qualities of alterable design features could produce tools with strong implications for process efficiency and industry competitiveness in the execution of its projects.
- Published
- 2021
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15. Subnanosecond phase transition dynamics in laser-shocked iron.
- Author
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Hwang H, Galtier E, Cynn H, Eom I, Chun SH, Bang Y, Hwang GC, Choi J, Kim T, Kong M, Kwon S, Kang K, Lee HJ, Park C, Lee JI, Lee Y, Yang W, Shim SH, Vogt T, Kim S, Park J, Kim S, Nam D, Lee JH, Hyun H, Kim M, Koo TY, Kao CC, Sekine T, and Lee Y
- Abstract
Iron is one of the most studied chemical elements due to its sociotechnological and planetary importance; hence, understanding its structural transition dynamics is of vital interest. By combining a short pulse optical laser and an ultrashort free electron laser pulse, we have observed the subnanosecond structural dynamics of iron from high-quality x-ray diffraction data measured at 50-ps intervals up to 2500 ps. We unequivocally identify a three-wave structure during the initial compression and a two-wave structure during the decaying shock, involving all of the known structural types of iron (α-, γ-, and ε-phase). In the final stage, negative lattice pressures are generated by the propagation of rarefaction waves, leading to the formation of expanded phases and the recovery of γ-phase. Our observations demonstrate the unique capability of measuring the atomistic evolution during the entire lattice compression and release processes at unprecedented time and strain rate., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)
- Published
- 2020
- Full Text
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16. Divide and conquer: A perspective on biochips for single-cell and rare-molecule analysis by next-generation sequencing.
- Author
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Lee AC, Lee Y, Lee D, and Kwon S
- Abstract
Recent advances in biochip technologies that connect next-generation sequencing (NGS) to real-world problems have facilitated breakthroughs in science and medicine. Because biochip technologies are themselves used in sequencing technologies, the main strengths of biochips lie in their scalability and throughput. Through the advantages of biochips, NGS has facilitated groundbreaking scientific discoveries and technical breakthroughs in medicine. However, all current NGS platforms require nucleic acids to be prepared in a certain range of concentrations, making it difficult to analyze biological systems of interest. In particular, many of the most interesting questions in biology and medicine, including single-cell and rare-molecule analysis, require strategic preparation of biological samples in order to be answered. Answering these questions is important because each cell is different and exists in a complex biological system. Therefore, biochip platforms for single-cell or rare-molecule analyses by NGS, which allow convenient preparation of nucleic acids from biological systems, have been developed. Utilizing the advantages of miniaturizing reaction volumes of biological samples, biochip technologies have been applied to diverse fields, from single-cell analysis to liquid biopsy. From this perspective, here, we first review current state-of-the-art biochip technologies, divided into two broad categories: microfluidic- and micromanipulation-based methods. Then, we provide insights into how future biochip systems will aid some of the most important biological and medical applications that require NGS. Based on current and future biochip technologies, we envision that NGS will come ever closer to solving more real-world scientific and medical problems.
- Published
- 2019
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17. Effects of cell death-inducing DFF45-like effector B on meat quality traits in Berkshire pigs.
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Yu GE, Kwon S, Hwang JH, An SM, Park DH, Kang DG, Kim TW, Kim IS, Park HC, Ha J, and Kim CW
- Subjects
- Animals, Apoptosis Regulatory Proteins metabolism, Polymorphism, Single Nucleotide, RNA, Messenger genetics, RNA, Messenger metabolism, Apoptosis Regulatory Proteins genetics, Meat standards, Quantitative Trait, Heritable, Swine genetics
- Abstract
Cell death-inducing DFF45-like effector (CIDE) B is a member of the CIDE family of apoptosis-inducing factors. In the present study, we detected a single nucleotide polymorphism (SNP), c.414G>A, which corresponds to the synonymous SNP 414Arg, in CIDE-B in the Berkshire pigs. We also analyzed the relationships between the CIDE-B SNP and various meat quality traits. The SNP was significantly associated with post-mortem pH
24h , water-holding capacity (WHC), fat content, protein content, drip loss, post-mortem temperature at 12 h (T12) and 24 h (T24) in a co-dominant model (P < 0.05). A significant association was detected between the SNP and post-mortem pH24h , fat content, protein content, drip loss, shear force, and T24 in gilts; and color parameter b*, WHC, and T24 in barrows (P < 0.05). The SNP was significantly correlated with the fat content, and CIDE-B mRNA expression was significantly upregulated during the early stage of adipogenesis, suggesting that CIDE-B may contribute towards initiation of adipogenesis (P < 0.05). Furthermore, CIDE-B mRNA was strongly expressed in the liver, kidney, large intestine, and small intestine, and weakly expressed in the stomach, lung, spleen, and white adipose tissue. These results indicate that the CIDE-B SNP is closely associated with meat quality traits and may be a useful DNA marker for improving pork quality.- Published
- 2017
- Full Text
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18. Air Pollution and Lung Function Loss: The Importance of Metabolic Syndrome.
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Zhang L, Crowley G, Haider SH, Zedan M, Kwon S, and Nolan A
- Published
- 2016
19. Prediction of childhood atopy by questionnaire.
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Simons E, Kwon S, Yang C, and Dell SD
- Subjects
- Age Factors, Canada, Child, Humans, Immunoglobulin E blood, Immunoglobulin E immunology, Sensitivity and Specificity, Skin Tests, Hypersensitivity, Immediate diagnosis, Hypersensitivity, Immediate epidemiology, Surveys and Questionnaires
- Published
- 2015
- Full Text
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20. Results of a retrospective comparative study: material cost for managing a series of large wounds in subjects with serious morbidity with a hydrokinetic fiber dressing or negative pressure wound therapy.
- Author
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Hermans MH, Kwon Lee S, Ragan MR, and Laudi P
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- Adult, Aged, California, Cost-Benefit Analysis, Female, Humans, Long-Term Care, Male, Middle Aged, Negative-Pressure Wound Therapy methods, Pressure Ulcer diagnosis, Pressure Ulcer economics, Retrospective Studies, Severity of Illness Index, Skilled Nursing Facilities, Surgical Wound Dehiscence diagnosis, Surgical Wound Dehiscence economics, Wound Healing physiology, Young Adult, Bandages economics, Health Care Costs, Negative-Pressure Wound Therapy economics, Pressure Ulcer therapy, Surgical Wound Dehiscence therapy
- Abstract
Unlabelled: This retrospective observational study analyzed lesions with regard to healing trends and cost of materials., Materials and Methods: The observed lesions were mostly postsurgical or stage IV pressure ulcers in patients with serious morbidity. The wounds were treated with a hydrokinetic fiber dressing (sorbion Sachet S, sorbion Gmbh & Co, a BSN medical company, Senden, Germany) (n = 26) or negative pressure wound therapy (NPWT) (n = 16)., Results: Primary healing trends (ie, reduction of wound size, change from necrosis to granulation tissue, and change from granulation tissue to epithelium) and secondary healing trends (ie, periwound conditions) were similar for wounds treated with the hydrokinetic dressing when compared to wounds treated with NPWT. Cost of materials was substantially lower for wounds treated with the hydrokinetic fiber dressing compared to the NPWT, with cost reductions of $1,640 (348%) to $2,242 (1794%) per wound, depending on the criteria used for the analysis., Conclusion: In this set of wounds, the hydrokinetic fiber dressing was shown to lead to similar healing results while providing substantial reductions of the cost of materials. For the types of wounds presented in this observational study, the hydrokinetic fiber dressing seems to be an effective substitution for negative pressure wound therapy.
- Published
- 2015
21. Tumor necrosis factor α level in cerebrospinal fluid for bacterial and aseptic meningitis: a diagnostic meta-analysis.
- Author
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Lv S, Zhao J, Zhang J, Kwon S, Han M, Bian R, Fu H, Zhang Y, and Pan H
- Subjects
- Humans, Biomarkers cerebrospinal fluid, Meningitis, Aseptic cerebrospinal fluid, Meningitis, Bacterial cerebrospinal fluid, Sensitivity and Specificity, Tumor Necrosis Factor-alpha cerebrospinal fluid
- Abstract
Background and Purpose: In our previous study, tumor necrosis factor α (TNF-α) was identified as an effective target for sepsis patients (Int J Clin Pract, 68, 2014, 520). TNF-α in cerebrospinal fluid (CSF) was also investigated for its utility in the differential diagnosis of bacterial and aseptic meningitis. However, there has been neither definite nor convincing evidence so far. Here the overall diagnostic accuracy of TNF-α in differentiation between bacterial and aseptic meningitis was evaluated through the meta-analysis of diagnostic tests., Methods: The sensitivity, specificity and other measures of accuracy were pooled using random effect models. Summary receiver operating characteristic curves were used to assess overall test performance. Publication bias was evaluated using funnel plots, and sensitivity analysis was also introduced., Results: A total of 21 studies involving bacterial meningitis (678) and aseptic meningitis (694) involved a total of 1372 patients. The pooled sensitivity and specificity for the TNF-α test were 0.83 [95% confidence interval (CI) 0.80-0.86, I(2) = 65.1] and 0.92 (95% CI 0.89-0.94, I(2) = 61.8), respectively. The positive likelihood ratio was 12.05 (95% CI 7.41-19.60, I(2) = 36.5), the negative likelihood ratio was 0.17 (95% CI 0.13-0.24, I(2) = 59.4), and TNF-α was significantly associated with bacterial meningitis, with a diagnostic odds ratio of 49.84 (95% CI 28.53-87.06, I(2) = 47.9). The overall accuracy of the TNF-α test was very high with the area under the curve 0.9317. Publication bias was absent, and sensitivity analysis suggested that our results were highly stable., Conclusions: Our meta-analysis suggested that TNF-α could be recommended as a useful marker for diagnosis of bacterial meningitis and differential diagnosis between bacterial and aseptic meningitis with high sensitivity and specificity. Thus, hospitals should be encouraged to conduct TNF-α tests in CSF after lumbar puncture., (© 2014 The Author(s) European Journal of Neurology © 2014 EAN.)
- Published
- 2014
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22. Anti-TNF-α therapy for patients with sepsis: a systematic meta-analysis.
- Author
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Lv S, Han M, Yi R, Kwon S, Dai C, and Wang R
- Subjects
- Antibodies, Monoclonal therapeutic use, Humans, Receptors, Tumor Necrosis Factor antagonists & inhibitors, Sepsis drug therapy, Shock, Septic drug therapy, Tumor Necrosis Factor-alpha antagonists & inhibitors
- Abstract
Objective: In humans, the role of anti-tumour necrosis factor (TNF)-α therapy in severe sepsis and septic shock is debatable. The aim of this meta-analysis was to determine the efficacy of anti-TNF-α therapies against placebo in patients with severe sepsis or septic shock., Methods: A structured literature search was undertaken to identify randomised controlled trials (RCTs) conducted in patients with severe sepsis or septic shock receiving anti-TNF-α therapy or placebo. A meta-analysis on relative risk (OR) with a 95% confidence interval (95% CI) was performed., Results: Seventeen studies with a total of 8971 patients were included. When all forms of anti-TNF-α therapy were pooled together, there was a significant reduction of 28-day all-cause mortality with respect to placebo (OR = 0.91, 95% CI: 0.83-0.99; p = 0.04). Subgroup analysis showed that anti-TNF-α antibodies (monoclonal and polyclonal) reduced mortality (OR = 0.90, 95% CI: 0.81-0.99; p = 0.04). Monoclonal antibodies enhanced survival (OR = 0.91, 95% CI: 0.82-1.00; p = 0.05), while polyclonal antibodies or receptor blockers did not enhance survival (OR = 0.71, 95% CI: 0.39-1.28, p = 0.25; OR = 0.95, 95% CI: 0.78-1.17, p = 0.65). There was a trend towards better survival in patients with high levels of IL-6 (> 1000 pg/ml) and patients with shock if they were treated with anti-TNF-α therapy (OR = 0.85, 95% CI: 0.72-1.00; OR = 0.80, 95% CI: 0.62-1.04). Publication bias and statistical heterogeneity (I(2) < 50% and p > 0.1) were absent. Sensitivity analysis suggests that these results are highly stable., Conclusions: This meta-analysis suggests that in patients with severe sepsis (before shock), immunotherapy with anti-TNF-α monoclonal antibodies reduces overall mortality. In patients with shock or high levels of IL-6 (> 1000 pg/ml), anti-TNF-α therapy may improve survival., (© 2014 John Wiley & Sons Ltd.)
- Published
- 2014
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23. Disparate effects of LPS infusion and carbohydrate overload on inflammatory gene expression in equine laminae.
- Author
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Kwon S, Moore JN, Robertson TP, Hurley DJ, Wagner B, and Vandenplas ML
- Subjects
- Animals, Dietary Carbohydrates administration & dosage, Endotoxemia genetics, Endotoxemia immunology, Endotoxemia veterinary, Female, Foot Diseases genetics, Foot Diseases immunology, Gene Expression drug effects, Horse Diseases genetics, Horse Diseases immunology, Inflammation genetics, Inflammation immunology, Interleukin-10 blood, Lameness, Animal etiology, Lameness, Animal genetics, Lameness, Animal immunology, Lipopolysaccharides administration & dosage, Male, Tumor Necrosis Factor-alpha blood, Foot Diseases veterinary, Hoof and Claw, Horse Diseases etiology, Horses genetics, Horses immunology, Inflammation veterinary
- Abstract
Although clinical evidence of endotoxemia has been associated with the development of acute laminitis in hospitalized horses with gastrointestinal diseases and endotoxins have been detected in the circulation of horses with experimentally-induced laminitis, it is unclear what role, if any, endotoxins have play the pathogenesis of the disease. Therefore, in the present study we compared the effects of endotoxin infusion to that of intra-gastric administration of mixed carbohydrate (CHO) on clinical signs of laminitis, plasma concentrations of TNF-α and IL-10, and laminar tissue expression of 20 genes associated with inflammation. Horses were divided into 4 groups: Control (water placebo, n=7), endotoxin infusion (LPS, n=6), CHO/Developmental (30% decrease in central venous pressure, n=6) and CHO/Lame (Obel grade I laminitis, n=7). Horses in the LPS group developed clinical signs consistent with systemic inflammation, had rapid increases in plasma concentrations of both TNF-α and IL-10, and leukopenia, but did not have any changes in laminar tissue expression of the genes associated with inflammation. In contrast, horses administered CHO developed clinical signs consistent with systemic inflammation, had more delayed increases in TNF-α, IL-10 and total leukocyte counts, and had marked increases in laminar tissue expression of the genes associated with inflammation. Only the horses administered CHO developed clinical signs of laminitis, providing additional credence to the concept that factors other than endotoxin are responsible for the changes in laminar tissue gene expression that occur during the development of acute equine laminitis., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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24. Frequency of electrocardiogram testing among HIV-infected patients at risk for medication-induced QTc prolongation.
- Author
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Patel N, Veve M, Kwon S, McNutt LA, Fish D, and Miller CD
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Cross-Sectional Studies, Diabetes Mellitus, Type 2, Female, Gastroesophageal Reflux, HIV Infections drug therapy, HIV Infections physiopathology, Hepacivirus, Humans, Hypertension, Long QT Syndrome epidemiology, Male, Middle Aged, Renal Insufficiency, Chronic, Risk Factors, Torsades de Pointes epidemiology, Young Adult, Drug Interactions physiology, Electrocardiography statistics & numerical data, Long QT Syndrome chemically induced
- Abstract
Objectives: HIV-infected patients are commonly prescribed several medications and are thus at risk for drug interactions that may result in QTc prolongation. We sought (1) to identify the frequency of electrocardiogram (ECG) monitoring (2), to determine the prevalence of drug interactions involving QTc-prolonging medications, and (3) to quantify the prevalence of QTc prolongation., Methods: A cross-sectional study was conducted among HIV-infected adults. Demographics, medications, drug interactions and comorbidities were abstracted from patients' medical records. Abnormal QTc interval was defined per the UK Committee for Proprietary Medicinal Products. Clinical characteristics were compared among ECG recipients and nonrecipients. Among ECG recipients, the prevalence and predictors of QTc prolongation were assessed., Results: Among the 454 patients included in the study, 80.8% were prescribed a medication associated with QTc prolongation and 39% had drug interactions expected to increase QTc prolongation risk. There were 138 patients (30.3%) who received ECG testing. Receipt of ECG monitoring was associated with increasing age, diabetes, increasing total number of medications and gastroesophageal reflux disease. Among ECG recipients, the prevalence of abnormal QTc interval was 27.5%. Chronic kidney disease [prevalence ratio (PR) 3.47; 95% confidence interval (CI) 1.37-8.83; P = 0.009], hepatitis C virus coinfection (PR 2.26; 95% CI 0.97-5.27; P = 0.06) and hypertension (PR 2.11; 95% CI 0.93-4.81; P = 0.07) were independently associated with an abnormal QTc interval., Conclusions: A low frequency of ECG testing was observed, despite a high use of medications associated with QTc prolongation. The risk of abnormal QTc interval was highest among patients with chronic kidney disease, hypertension and hepatitis C virus coinfection., (© 2013 British HIV Association.)
- Published
- 2013
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25. Pharmacokinetic assessment of ketanserin in the horse.
- Author
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Aljuffali IA, Brainard BM, Moore JN, Kwon S, Allen D, Robertson TP, and Arnold RD
- Subjects
- Animals, Area Under Curve, Female, Half-Life, Horses metabolism, Ketanserin blood, Ketanserin chemistry, Molecular Structure, Platelet Aggregation Inhibitors blood, Platelet Aggregation Inhibitors chemistry, Horses blood, Ketanserin pharmacokinetics, Platelet Aggregation Inhibitors pharmacokinetics
- Abstract
The purpose of this study was to determine the pharmacokinetics (PK) of the 5-HT(2A) receptor antagonist ketanserin in healthy adult horses, and to develop a computational model that could be used to optimize dosing. Plasma concentrations of ketanserin were determined using liquid chromatography with mass spectrometry after single and multiple intravenous administration in the horse. A two-compartment linear pharmacokinetic model described the plasma concentration-time profile of ketanserin after single and multiple doses in healthy horses; the terminal half-life was 11.5 h; steady-state volume of distribution was 10.5 L/kg; AUC was 115 ng · h/mL; and clearance was 0.87 L/h/kg. Model simulations followed by the examination in three healthy horses suggest 0.3 mg/kg q.8 h exhibited linear PK and produced consistent systemic blood concentrations of ketanserin above 3 ng/mL., (© 2011 Blackwell Publishing Ltd.)
- Published
- 2012
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26. In vivo dynamic imaging of intestinal motions using diet-related autofluorescence.
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Kwon S, Davies-Venn C, and Sevick-Muraca EM
- Subjects
- Animals, Diet, Digestion, Intestine, Small anatomy & histology, Intestine, Small physiology, Lasers, Mice, Peristalsis, Spectroscopy, Near-Infrared, Chlorophyll chemistry, Fluorescence, Gastrointestinal Motility physiology, Intestines anatomy & histology, Intestines physiology
- Abstract
Background: Tissue background autofluorescence induced by standard murine diets containing chlorophyll is a significant problem for fluorescence whole-body imaging. However, as red chlorophyll autofluorescence delineates the gastrointestinal (GI) tract in the abdomen of the mouse, it should be possible to dynamically and non-invasively image intestinal motions. Herein, we non-invasively imaged for the first time intestinal motions, such as peristaltic and segmental motions, without an exogenous imaging agent, using red chlorophyll fluorescence., Methods: Mice were illuminated with 660-nm light from a laser diode and autofluorescence at 710 nm was acquired dynamically for 5 min with 200-ms exposure time. Fluorescent imaging data were analyzed to generate a three-dimensional spatiotemporal map to quantitate intestinal motions., Key Results: Peristaltic and segmental motions were observed in vivo in mice. Our quantification showed that the frequency and propagation velocity of peristaltic contractile waves in the small intestine were measured to be 28.6 cycles per min and 1.82 ± 0.56 cm s(-1), respectively., Conclusions & Inferences: This simple, but unexplored imaging technique can provide a means to monitor intestinal motility disorders and response to therapeutic agents., (© 2012 Blackwell Publishing Ltd.)
- Published
- 2012
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27. Concentration of indocyanine green does not significantly influence lymphatic function as assessed by near-infrared imaging.
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Aldrich MB, Davies-Venn C, Angermiller B, Robinson H, Chan W, Kwon S, and Sevick-Muraca EM
- Subjects
- Animals, Female, Image Processing, Computer-Assisted, Lymphography, Mice, Mice, Inbred C57BL, Spectroscopy, Near-Infrared, Tissue Distribution, Coloring Agents pharmacokinetics, Fluorescent Dyes pharmacokinetics, Indocyanine Green pharmacokinetics, Lymphatic System metabolism
- Abstract
Background: Absorbance of near-infrared (600-800 nm) light by the tissue components water, melanin, and hemoglobin is minimal. This property allows the use of near-infrared-emitting fluorophores for noninvasive, in vivo, real-time imaging of tissue, without the interference of autofluorescence experienced with imaging in other wavelength ranges. Near-infrared (NIR) fluorescence imaging has been used to noninvasively image lymphatic architecture and pumping function in animals, as well as in humans. The effects of different doses of a NIR dye, indocyanine green (ICG), on lymphatic function have been questioned. This study aims to address these concerns in the context of a mouse inguinal-to-axillary lymphatic imaging model., Methods and Results: We measured lymph propulsive velocity and frequency using an imaging system composed of a laser diode for excitation of the dye, an image intensifier, and an intensified charge-coupled device (ICCD) camera to capture real-time images. At 0.32, 0.645, and 1.3 mM ICG, no significant differences in lymphatic propulsive velocity or frequency were observed. Additionally, the use of other NIR imaging agents did not result in significant differences., Conclusions: The use of different concentrations of ICG and the use of other near-infrared fluorophores for optical imaging of lymphatics does not significantly affect lymphatic propulsive velocity or frequency.
- Published
- 2012
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28. Indole-3-carbinol synergistically sensitises ovarian cancer cells to bortezomib treatment.
- Author
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Taylor-Harding B, Agadjanian H, Nassanian H, Kwon S, Guo X, Miller C, Karlan BY, Orsulic S, and Walsh CS
- Subjects
- Animals, Bortezomib, Cell Cycle drug effects, Cell Line, Tumor, Drug Synergism, Female, Flow Cytometry, Humans, Mice, Mice, Nude, Oligonucleotide Array Sequence Analysis, Real-Time Polymerase Chain Reaction, Xenograft Model Antitumor Assays, Antineoplastic Agents pharmacology, Boronic Acids pharmacology, Indoles pharmacology, Ovarian Neoplasms pathology, Pyrazines pharmacology
- Abstract
Background: Bortezomib is a proteasome inhibitor with minimal clinical activity as a monotherapy in solid tumours, but its combination with other targeted therapies is being actively investigated as a way to increase its anticarcinogenic properties. Here, we evaluate the therapeutic potential of co-treatment with bortezomib and indole-3-carbinol (I3C), a natural compound found in cruciferous vegetables, in human ovarian cancer., Methods: We examined the effects of I3C, bortezomib and cisplatin in several human ovarian cancer cell lines. Synergy was determined using proliferation assays and isobologram analysis. Cell cycle and apoptotic effects were assessed by flow cytometry. The mechanism of I3C and bortezomib action was determined by RNA microarray studies, quantitative RT-PCR and western blotting. Antitumour activity of I3C and bortezomib was evaluated using an OVCAR5 xenograft mouse model., Results: I3C sensitised ovarian cancer cell lines to bortezomib treatment through potent synergistic mechanisms. Combination treatment with bortezomib and I3C led to profound cell cycle arrest and apoptosis as well as disruptions to multiple pathways, including those regulating endoplasmic reticulum stress, cytoskeleton, chemoresistance and carcinogen metabolism. Moreover, I3C and bortezomib co-treatment sensitised ovarian cancer cells to the standard chemotherapeutic agents, cisplatin and carboplatin. Importantly, in vivo studies demonstrated that co-treatment with I3C and bortezomib significantly inhibited tumour growth and reduced tumour weight compared with either drug alone., Conclusion: Together, these data provide a novel rationale for the clinical application of I3C and bortezomib in the treatment of ovarian cancer.
- Published
- 2012
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29. Relationship between interpregnancy interval and birth defects in Washington State.
- Author
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Kwon S, Lazo-Escalante M, Villaran MV, and Li CI
- Subjects
- Adult, Case-Control Studies, Female, Humans, Infant, Newborn, Male, Pregnancy, Pregnancy Outcome, Risk Factors, Washington epidemiology, Young Adult, Birth Intervals statistics & numerical data, Congenital Abnormalities epidemiology
- Abstract
Objective: Interpregnancy interval (IPI) influences numerous adverse perinatal outcomes. IPI's impact on birth defects is unclear., Study Design: We conducted a population-based case-control study, using 1998 to 2008 administrative data from Washington State. A total of 10, 772 cases, women whose second of two births resulted in an infant with a birth defect, were compared with 32 ,310 controls, women whose second of two births did not result in an infant with a birth defect., Result: Compared with mothers with an IPI between 18 to 23 months, those with an IPI <6 months or ≥60 months had elevated risks of delivering an infant with a birth defect (odds ratio=1.15, 95% confidence interval: 1.03 to 1.28, and odds ratio=1.15, 95% confidence interval: 1.04 to 1.26, respectively)., Conclusion: We observed a J-shaped relationship between IPI and risk of having an infant with a birth defect. As this is one of the first studies to evaluate this association, confirmatory studies are needed.
- Published
- 2012
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30. Ambrisentan for sarcoidosis associated pulmonary hypertension.
- Author
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Judson MA, Highland KB, Kwon S, Donohue JF, Aris R, Craft N, Burt S, and Ford HJ
- Subjects
- Adult, Antihypertensive Agents adverse effects, Exercise Test, Exercise Tolerance drug effects, Female, Humans, Hypertension, Pulmonary etiology, Hypertension, Pulmonary physiopathology, Lung drug effects, Lung physiopathology, Male, Middle Aged, North Carolina, Phenylpropionates adverse effects, Prospective Studies, Pyridazines adverse effects, Quality of Life, Recovery of Function, Respiratory Function Tests, South Carolina, Surveys and Questionnaires, Time Factors, Treatment Outcome, Antihypertensive Agents therapeutic use, Hypertension, Pulmonary drug therapy, Phenylpropionates therapeutic use, Pyridazines therapeutic use, Sarcoidosis complications
- Abstract
Background: Sarcoidosis associated pulmonary hypertension (SAPH) is associated with significant morbidity and mortality. There is a paucity of information concerning therapy for this condition., Methods: We performed a prospective, open-label, proof of concept trial of ambrisentan for SAPH. 21 subjects with SAPH received 5 mg/day of ambrisentan for 4 weeks and then 10/mg day for 20 subsequent weeks., Results: No significant change was noted in the 6-minute walk distance over the course of the study (mean change between week 0 and 24: 9.8 +/- 54.6 meters, p: NS). There were also no significant differences between weeks 0 and 24 in terms of dyspnea as measured by the modified Borg scale, serum brain naturetic peptide, diffusing capacity, and quality of life as measured by the Short Form-36. There was a high dropout rate: overall: 11/21, 52%; social reasons: 3/21, 14%; medical reasons: 8/21, 38% because of dyspnea: 6/21, 29% and/or edema: 4/21, 19%. Of those who completed the 24 week study (10/21, 48%), there was an improvement in their WHO functional class and a marked improvement in their health related quality of life as measured by the St. George Respiratory questionnaire (-15.3 +/- 25.0). However both these improvments did not reach statistical significance possibly because of the small sample size., Conclusion: Although ambrisentan was not well tolerated by many of these subjects with SAPH, in those who remained in this 24-week trial, improvements in WHO functional class and in health related quality of life suggested a possible benefit of this drug in selected patients.
- Published
- 2011
31. Non-invasive, dynamic imaging of murine intestinal motility.
- Author
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Kwon S and Sevick-Muraca EM
- Subjects
- Animals, Female, Humans, Mice, Mice, Inbred C57BL, Coloring Agents metabolism, Gastrointestinal Motility physiology, Gastrointestinal Tract anatomy & histology, Gastrointestinal Tract physiology, Indocyanine Green metabolism, Spectroscopy, Near-Infrared methods
- Abstract
Background: After intravenous (i.v.) administration, indocyanine green (ICG) is known to be secreted into bile from the liver via the biliary tracts, enabling fluorescent delineation of the intestine. In addition, ICG is a near-infrared (NIR) excitable fluorophore, capable of providing exogenous contrast for rapid NIR fluorescence imaging. We sought to quantify the intestinal motility using dynamic NIR fluorescence imaging after injection of ICG., Methods: C57BL6 mice were dynamically imaged immediately before and up to 24h after i.v. and intradermal (i.d.) injection of 50 and 10μL of ICG, respectively. Necropsy was also performed 1h postinjection and the entire gastrointestinal tract was isolated and exposed for ex vivo fluorescence imaging., Key Results: The secretion of ICG-laden fluorescent bile into the duodenum was observed in vivo and confirmed in situ. Different patterns of the intestinal motility, such as peristaltic and segmental motions, were dynamically imaged in vivo. Our imaging data showed that the frequency of contractions ranged from 27 to 35cyclesmin(-1) and the propagation velocity of peristaltic waves ranged from 0.82±0.5 to 2.04±1.12cms(-1) ., Conclusions & Inferences: Dynamic NIR fluorescence imaging with injection of ICG can provide a method for diagnostic motility testing for intestinal motility disorders or dysfunction and for potential evaluation of therapeutic agents., (© 2011 Blackwell Publishing Ltd.)
- Published
- 2011
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32. Effects of clopidogrel and aspirin on platelet aggregation, thromboxane production, and serotonin secretion in horses.
- Author
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Brainard BM, Epstein KL, LoBato D, Kwon S, Papich MG, and Moore JN
- Subjects
- Animals, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Area Under Curve, Aspirin pharmacokinetics, Blood Platelets physiology, Clopidogrel, Cross-Over Studies, Female, Horses blood, Male, Platelet Activation drug effects, Platelet Aggregation Inhibitors pharmacology, Platelet Count veterinary, Prospective Studies, Random Allocation, Thrombosis prevention & control, Thrombosis veterinary, Thromboxane B2 blood, Ticlopidine pharmacokinetics, Ticlopidine pharmacology, Aspirin pharmacology, Blood Platelets drug effects, Horses physiology, Serotonin blood, Thromboxane B2 biosynthesis, Ticlopidine analogs & derivatives
- Abstract
Background: Critically ill horses are susceptible to thrombotic disease, which might be related to increased platelet reactivity and activation., Objectives: To compare the effect of oral clopidogrel and aspirin (ASA) on equine platelet function., Animals: Six healthy adult horses., Methods: Horses received clopidogrel (2 mg/kg p.o. q24h) or ASA (5 mg/kg p.o. q24h) for 5 days in a prospective randomized cross-over design. Platelet aggregation responses to adenosine diphosphate (ADP) and collagen via optical aggregometry, and platelet secretion of serotonin (5HT) and production of thromboxane B(2) (TXB(2) ) by ELISA were evaluated. In horses receiving clopidogrel, high-performance liquid chromatography analysis for clopidogrel and its carboxylic-acid metabolite SR 26334 was performed., Results: SR 26334 was identified in all clopidogrel-treated horses, although the parent compound was not detected. Clopidogrel resulted in decreases in ADP-induced platelet aggregation persisting for 120 hours after the final dose. ADP-induced platelet aggregation decreased from a baseline of 70.2 ± 14.7% to a minimum of 15.9 ± 7.7% 24 hours after the final dose (P < .001). Collagen-induced aggregation decreased from a baseline of 93 ± 9.5% to a minimum of 70.8 ± 16.9% 48 hours after the final dose (P < .001). ASA did not decrease platelet aggregation with either agonist. ASA decreased serum TXB(2) from a baseline value of 1310 ± 1045 to 128 ± 64 pg/mL within 24 hours (P < .01)., Conclusions and Clinical Importance: Clopidogrel effectively decreases ADP-induced platelet aggregation in horses, and could have therapeutic applications for equine diseases associated with platelet activation., (Copyright © 2010 by the American College of Veterinary Internal Medicine.)
- Published
- 2011
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33. Pulmonary vein stenosis: Case report and literature review.
- Author
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Amin R, Kwon S, Moayedi Y, and Sweezey N
- Subjects
- Cardiac Catheterization, Constriction, Pathologic complications, Female, Humans, Infant, Treatment Outcome, Ultrasonography, Hypertension, Pulmonary etiology, Pulmonary Veins diagnostic imaging, Pulmonary Veins pathology
- Abstract
Background: Pulmonary vein stenosis is a rare cause of pulmonary hypertension, with variable onset and presentation. One or more of the four pulmonary veins can be primarily or secondarily affected. A five-month-old girl presented with respiratory distress, lethargy and cyanosis requiring intubation., Methods: Echocardiography showed right ventricular dilation, a right ventricular systolic pressure of 97 mmHg, decreased ejection fraction and turbulent flow at the left atrium. Cardiac catheterization revealed stenosis of the left-sided pulmonary veins, for which she underwent a Coles procedure., Results: Postoperatively, there was a transient improvement in the patient's pulmonary hypertension but she subsequently deteriorated. Her prognosis was considered bleak, and a decision was made with the family to withdraw care., Conclusion: Pulmonary vein stenosis is a rare cause of pulmonary hypertension, and is associated with significant morbidity and mortality. Surgical intervention may be of benefit in selected cases. It stands to reason that any treatment will have the best chance of success if completed before the pulmonary hypertension becomes fixed. Early diagnosis depends on a high index of clinical suspicion.
- Published
- 2009
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34. Inhaled iloprost for sarcoidosis associated pulmonary hypertension.
- Author
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Baughman RP, Judson MA, Lower EE, Highland K, Kwon S, Craft N, and Engel PJ
- Subjects
- Administration, Inhalation, Adult, Aged, Female, Follow-Up Studies, Humans, Hypertension, Pulmonary physiopathology, Iloprost administration & dosage, Male, Middle Aged, Prognosis, Quality of Life, Sarcoidosis, Pulmonary physiopathology, Surveys and Questionnaires, Vasodilator Agents administration & dosage, Hypertension, Pulmonary chemically induced, Iloprost adverse effects, Pulmonary Wedge Pressure drug effects, Sarcoidosis, Pulmonary drug therapy, Vasodilator Agents adverse effects
- Abstract
Rationale: Patients with sarcoidosis associated pulmonary hypertension (SAPH) have responded to systemic prostacyclin therapy., Objectives: To determine the rate of response to inhaled prostacyclin, iloprost, in SAPH., Methods: Sarcoidosis patients with pulmonary hypertension and no evidence for left ventricular dysfunction were enrolled in an open label, prospective study. Patients underwent right heart catheterization and six minute walk (6MW) test. Quality of life was evaluated using several instruments, including the Saint George Respiratory Questionnaire (SGRQ). Patients received 5 mcg of inhaled iloprost every 2-3 hours while awake. After four months of therapy, patients underwent repeat cardiac catheterization, 6 MW test, and completed quality of life questionnaires., Measurements and Main Results: Of the 22 patients enrolled, 15 completed all 16 weeks of therapy. The most common reasons for study discontinuation included drug associated cough (3 patients) and compliance with the prescribed number of treatments per day (2 patients). Six patients experienced a 20% or greater decrease in pulmonary vascular resistance (PVR) from baseline with five of these six patients also showing > or = 5 mm Hg reduction in PA mean. Although three patients improved the 6MW distance by at least 30 meters, only one had a decrease in PVR. At 16 weeks a significant decrease was reported in the SGRQ activity score (p = 0.0273), with seven patients having a 4 point or greater decrease., Conclusion: Inhaled iloprost as monotherapy was associated with an improvement in pulmonary hemodynamics and quality of life as assessed by the SGRQ activity score in some sarcoidosis patients with SAPH.
- Published
- 2009
35. What is a meaningful change in physical performance? Findings from a clinical trial in older adults (the LIFE-P study).
- Author
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Kwon S, Perera S, Pahor M, Katula JA, King AC, Groessl EJ, and Studenski SA
- Subjects
- Aged, Aged, 80 and over, Health Education, Humans, Self Disclosure, Single-Blind Method, Walking, Aging physiology, Disability Evaluation, Exercise Therapy, Physical Fitness, Research Design
- Abstract
Objective: Performance measures provide important information, but the meaning of change in these measures is not well known. The purpose of this research is to 1) examine the effect of treatment assignment on the relationship between self-report and performance; 2) to estimate the magnitude of meaningful change in 400-meter walk time (400MWT), 4-meter gait speed (4MGS), and Short Physical Performance Battery (SPPB) and 3) to evaluate the effect of direction of change on estimates of magnitude., Design: This is a secondary analysis of data from the LIFE-P study, a single blinded randomized clinical trial. Using change over one year, we applied distribution-based and anchor-based methods for self-reported mobility to estimate minimally important and substantial change in 400MWT, 4MGS and SPPB., Setting: Four university-based clinical research sites., Participants: Sedentary adults aged 70-89 whose SPPB scores were less than 10 and who were able to complete a 400MW at baseline (n=424)., Interventions: A structured exercise program versus health education., Measurements: 400MWT, 4MGS, SPPB., Results: Relationships between self-report and performance measures were consistent between treatment arms. Minimally significant change estimates were 400MWT: 20-30 seconds, 4MGS: 0.03-0.05m/s and SPPB: 0.3 - 0.8 points. Substantial changes were 400MWT: 50-60 seconds, 4MGS: 0.08m/s, SPPB: 0.4 - 1.5 points. Magnitudes of change for improvement and decline were not significantly different., Conclusions: The magnitude of clinically important change in physical performance measures is reasonably consistent using several analytic techniques and appears to be achievable in clinical trials of exercise. Due to limited power, the effect of direction of change on estimates of magnitude remains uncertain.
- Published
- 2009
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36. Complications of distraction lengthening in the hand.
- Author
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Heo CY, Kwon S, Back GH, and Chung MS
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Cohort Studies, Female, Hand Deformities, Acquired diagnosis, Hand Deformities, Acquired etiology, Hand Deformities, Congenital diagnostic imaging, Hand Deformities, Congenital pathology, Humans, Male, Osteogenesis, Distraction instrumentation, Radiography, Reoperation, Retrospective Studies, Treatment Failure, External Fixators adverse effects, Finger Phalanges surgery, Hand Deformities, Acquired surgery, Hand Deformities, Congenital surgery, Metacarpal Bones surgery, Osteogenesis, Distraction adverse effects
- Abstract
This study examined the features of 16 complications from 51 distraction lengthenings in the hands of 43 patients. From 1996 to 2006, 24 metacarpals and 27 phalanges were lengthened at a rate of 0.5 and 0.25 mm/day, respectively, using a callus distraction technique. The indications were congenital (33 cases in 27 patients) and traumatic (18 cases in 16 patients) deformities. The average percentage lengthening in the phalanges and metacarpals was 62% (16 mm) and 63% (34 mm), respectively. The distraction rates in the phalanges and metacarpals were 69 and 52 days/cm, respectively. The overall complication rate was 31%. Major complications requiring secondary procedures were non-union (one case), fracture (one case), premature union (one case), angulations (two cases) and dislodgment of pins (two cases). The minor complications encountered were delayed callus formation (four cases), joint stiffness (four cases) and soft tissue thinning (one case). Traumatic deformities had more complications than the congenital ones (nine of 18 cases and seven of 33 cases, respectively). The phalanges had a higher rate of complication than the metacarpals (11 of 27 cases and four of 24 cases, respectively). Most patients with complications except for two children with dislodgment were as satisfied with the final results as those without complications. Although callus distraction in the hand requires a long treatment period and has a relatively high rate of complication, it appears to be effective in achieving adequate bone length. A high level of patient compliance and prompt management of complications by an experienced surgeon are essential for achieving good results.
- Published
- 2008
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37. High production of beta-thujaplicin glycosides by immobilized plant cells of Nicotiana tabacum.
- Author
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Kwon S, Shimoda K, Hamada H, Ishihara K, Masuoka N, and Hamada H
- Subjects
- Cell Line, Molecular Structure, Monoterpenes chemistry, Tropolone chemistry, Tropolone metabolism, Glycosides metabolism, Monoterpenes metabolism, Nicotiana metabolism, Tropolone analogs & derivatives
- Abstract
beta-Thujaplicin (hinokitiol) is a tropolone derivative present in the heartwood of cupressaceous plants and is used as a medicine, a food additive, and a preservative, and in cosmetics as hair tonic. The cultured plant cells of Nicotiana tabacum glycosylated beta-thujaplicin to two glucosides, 4-isopropyltropolone 2-O-beta-D-glucoside (6%) and 6-isopropyltropolone 2-O-beta-D-glucoside (12%), and two gentiobiosides, 4-isopropyltropolone 2-O-beta-D-gentiobioside (2%) and 6-isopropyltropolone 2-O-beta-D-gentiobioside (5%) after 48 h incubation. The use of immobilized cells of N. tabacum in sodium alginate gel much improved the yield of the products; the glycosylation of beta-thujaplicin with immobilized N. tabacum gave the glycoside products, 4-isopropyltropolone 2-O-beta-D-glucoside (11%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (6%), 6-isopropyltropolone 2-O-beta-D-glucoside (20%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (10%). On the other hand, 4-isopropyltropolone 2-O-beta-D-glucoside (14%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (7%), 6-isopropyltropolone 2-O-beta-D-glucoside (33%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (13%) were obtained through the biotransformation with immobilized cells in the medium without iron ions. In comparison with the case of bioconversion in the normal medium containing iron ions, removal of iron ions improved the yields of products.
- Published
- 2008
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38. Analysis of percutaneous transhepatic cholangioscopy-related complications and the risk factors for those complications.
- Author
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Oh HC, Lee SK, Lee TY, Kwon S, Lee SS, Seo DW, and Kim MH
- Subjects
- Adult, Aged, Aged, 80 and over, Biliary Tract Diseases diagnosis, Cholangiopancreatography, Endoscopic Retrograde, Female, Follow-Up Studies, Humans, Laparoscopy methods, Magnetic Resonance Imaging, Male, Middle Aged, Minimally Invasive Surgical Procedures methods, Postoperative Complications diagnosis, Postoperative Complications epidemiology, Retrospective Studies, Risk Factors, Tomography, X-Ray Computed, Treatment Outcome, Biliary Tract Diseases surgery, Endoscopy, Digestive System adverse effects, Endoscopy, Digestive System methods, Laparoscopy adverse effects, Minimally Invasive Surgical Procedures adverse effects
- Abstract
Background and Study Aims: Percutaneous transhepatic cholangioscopy (PTC) is being increasingly used for patients with biliary tract diseases. The aim of this study was to assess the safety of this procedure, and we systematically analyzed PTC-related complications and the risk factors for those complications., Patients and Methods: A total of 364 patients who underwent PTC were included in the study. The initial diagnoses, the indications for PTC, the complications that occurred during the procedures, and the risk factors for these complications were retrospectively analyzed., Results: The overall incidence of complications was 12.9 % for percutaneous transhepatic biliary drainage (PTBD), 12.8 % for tract dilation, and 6.9 % for tract maturation. Complications developed in 58/848 PTC sessions (6.9 %). Cholangitis and bacteremia were associated with PTBD and tract dilation, catheter migration and blockage with tract maturation, and bile duct injury with PTC. Mild complications occurred in 80 patients (22.2 %) during the preparation stages and in 43 sessions (5.1 %) during the PTC itself. Severe complications, including severe hemobilia, hemoperitoneum, rupture of the sinus tract, and ductal injury developed in 17 patients (4.7 %) during the preparation period, and in 15 patients (4.1 %) during PTC. The overall incidence of severe complications along the entire course was 8.2 % (30/364 patients). No patient died or required surgery. Intraductal manipulations, such as electrohydraulic lithotripsy or balloon dilation, and the first session of PTC were risk factors for procedure-related complications., Conclusions: PTC is a relatively safe and well-tolerated method for treating certain biliary tract diseases. Meticulous patient selection and a cooperative team approach are required in order to minimize the incidence of complications and to provide effective management.
- Published
- 2007
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39. [Hans-Christian Jacobaeus (1879-1937): The inventor of human laparoscopy and thoracoscopy].
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Hatzinger M, Häcker A, Langbein S, Kwon S, Hoang-Böhm J, and Alken P
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- Animals, History, 19th Century, History, 20th Century, Humans, Sweden, Laparoscopy history, Thoracoscopy history
- Abstract
Already 94 years ago in 1910, Dr. Hans Christian Jacobaeus performed the first clinical laparoscopic surgery in Stockholm. His pioneering procedure was based on the animal experiments of Georg Kelling (1866-1945), a German physician from Dresden, who performed the first laparoscopic intervention in 1901 using a Nitze cystoscope in a dog. In 1910 Jacobaeus published his first experiences with laparoscopic surgery in the Münchner Medizinische Wochenschrift under the title "The possibility to perform cystoscopy in examinations of serous cavities." He used this technique for diagnostic purposes in unclear abdominal complaints and functional impairment. Jacobaeus was the first who pointed out the possibility of causing injury to organs, especially the gut, by inserting the trocar. In 1910 Jacobaeus recognized the immense diagnostic and therapeutic possibilities of laparoscopic surgery, but also the difficulties and limits. He also was the first who recognized the need to complete training sessions on animals and corpses. He demanded the development of special laparoscopic instruments to optimize and simplify the operation.
- Published
- 2006
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40. New ORP/pH based control strategy for chlorination and dechlorination of wastewater: pilot scale application.
- Author
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Kim H, Kwon S, Han S, Yu M, Kim J, Gong S, and Colosimo MF
- Subjects
- Chloramines chemistry, Chlorine Compounds chemistry, Disinfectants, Disinfection, Hydrogen-Ion Concentration, Sulfites, Time Factors, Water Pollutants, Chemical analysis, Chlorine chemistry, Sewage, Waste Disposal, Fluid methods, Water Purification methods
- Abstract
Due to its efficiency and low capital demands, chlorination has been widely used for disinfection in many wastewater treatment plants. Since the oxidation power of free chlorine is bigger than combined chlorines which are formed from the reaction between chlorine and reducing agents in water (especially, NH4+ and organic nitrogen), for effective disinfection, excess amount of chlorine is added until all the reducing agents are oxidized and free chlorine is available. After chlorination, chlorine residues in wastewater are usually reduced with SO2 or sulfites before the treated wastewater is discharged, since they are toxic to aquatic life. Addition of excess amount of SO2 or sulfite should be avoided. Otherwise, they consume dissolved oxygen in a river or stream and may have adverse impact on the aquatic life. Determination of wastewater chlorine demand and of sulfite dosages for dechlorination has been a challenge to WWTP operators, due to the dynamic characteristics of wastewater. Recently, a new ORP/pH based approach to determine chlorine demand and sulfite dosage was proposed. The method utilizes significant points occurring on the pH and ORP profiles during chlorination and dechlorination titrations. In this study, the proposed automatic titration system has been implemented into a control system to optimize chlorine and sulfite doses for a pilot scale chlorination/dechlorination system. In short, the disinfection system with the pH/ORP based controller showed very successful results; complete inactivation of total coliforms, and almost zero residual chlorines and high DO in its effluent.
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- 2006
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41. New process control strategy for wastewater chlorination and dechlorination using ORP/pH.
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Kim H, Kwon S, Han S, Yu M, Gong S, and Colosimo MF
- Subjects
- Disinfectants chemistry, Hydrogen-Ion Concentration, Oxidation-Reduction, Sulfites chemistry, Water Purification, Chlorine chemistry, Waste Disposal, Fluid methods
- Abstract
Due to its efficiency and relatively low capital demanding, many wastewater treatment plants have applied chlorination for disinfection of treated wastewater before discharging it. However, determination of optimal doses of chlorine for chlorination and sulfite for dechlorination, which removes residual chlorine, should made to guarantee complete destruction of microorganisms in treated wastewater and to protect aquatic life in a receiving stream. In this study, a new ORP/pH based approach to determine endpoints of breakpoint chlorination and of dechlorinating titration and to optimize doses of chlorine and sulfite. In this new method, significant points on the ORP and pH profiles occurring during the titrations for chlorination and dechlorination were utilized to determine chlorine demand and sulfite dosage.
- Published
- 2006
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42. Fabrication of large number density platinum nanowire arrays by size reduction lithography and nanoimprint lithography.
- Author
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Yan XM, Kwon S, Contreras AM, Bokor J, and Somorjai GA
- Abstract
Large number density Pt nanowires with typical dimensions of 12 microm x 20 nm x 5 nm (length x width x height) are fabricated on planar oxide supports. First sub-20 nm single crystalline silicon nanowires are fabricated by size reduction lithography, and then the Si nanowire pattern is replicated to produce a large number of Pt nanowires by nanoimprint lithography. The width and height of the Pt nanowires are uniform and are controlled with nanometer precision. The nanowire number density is 4 x 10(4) cm(-1), resulting in a Pt surface area larger than 2 cm(2) on a 5 x 5 cm(2) oxide substrate. Bimodal nanowires with different width have been generated by using a Pt shadow deposition technique. Using this technique, alternating 10 and 19 nm wide nanowires are produced.
- Published
- 2005
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43. Impact of surface heterogeneity on mercury uptake by carbonaceous sorbents under UHV and atmospheric pressure.
- Author
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Kwon S, Borguet E, and Vidic RD
- Subjects
- Adsorption, Oxidation-Reduction, Oxygen chemistry, Pressure, Temperature, Carbon chemistry, Mercury chemistry
- Abstract
Chemical and morphological heterogeneities of carbon sorbents play important roles in gas-phase adsorption. However, the specific chemical complexes and topological structures of carbon that favor or impede elemental mercury uptake are not well understood and are the subject of this study. Temperature programmed desorption (TPD) with a model carbonaceous material (highly oriented pyrolytic graphite, HOPG) under ultrahigh vacuum (UHV) conditions and fixed bed adsorption by activated carbon (BPL) at atmospheric pressure were combined to investigate the effects of chemical and morphological heterogeneities on mercury adsorption by carbonaceous surfaces. TPD results show that mercury adsorption at 100 K onto HOPG surfaces with and without chemical functional groups and topological heterogeneity created by plasma oxidation occurs through physisorption. The removal of chemical functionalities from the HOPG surface enhances mercury physisorption. Plasma-oxidation of HOPG provides additional surface area for mercury adsorption. However, the pits created by plasma oxidation are more than 10 nm in diameter and do not simulate microporosity that predominates in activated carbons. Mercury adsorption by activated carbon at atmospheric pressure occurs through two distinct mechanisms. Physisorption governs mercury adsorption at lower temperatures (i.e., below 348 K), while chemisorption predominates at high adsorption temperatures (i.e., above 348 K). Presence of water on activated carbon surface enhances mercury uptake by both physisorption and chemisorption. Oxygen containing functional groups reduce mercury uptake by physisorption by blocking access to the micropores. No significant impact of oxygen functionalities was observed in the chemisorption regime. The key findings of this study open the possibility to apply scientific information obtained from the studies with simple surfaces such as HOPG under ideal conditions (UHV) to industrial sorbents under realistic process conditions.
- Published
- 2002
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44. Mechanisms of synergistic cytokine-induced nitric oxide production in human alveolar epithelial cells.
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Kwon S, Newcomb RL, and George SC
- Subjects
- Arginine pharmacology, Biopterins pharmacology, Cell Line, Transformed, Cell Nucleus metabolism, Epithelial Cells drug effects, Epithelial Cells metabolism, Flavin Mononucleotide pharmacology, Flavin-Adenine Dinucleotide pharmacology, Humans, NF-kappa B metabolism, Protein Transport, Pulmonary Alveoli cytology, Pulmonary Alveoli drug effects, Biopterins analogs & derivatives, Cytokines physiology, Nitric Oxide biosynthesis, Pulmonary Alveoli metabolism
- Abstract
Nitric oxide (NO) derived from inducible NO synthase (iNOS) at sites of inflammation is closely related to host defense against infection and airway inflammation. Cytokines are known to stimulate NO production in human alveolar epithelial cells in a synergistic (nonlinear or nonadditive) manner. The mechanism of this synergy is not known. We measured the activation of the transcription factor NF-kappaB, the iNOS protein, and NO production in A549 monolayers (human alveolar epithelial cell line) in response to different combinations of IL-1beta, INF-gamma, and TNF-alpha (100 ng/ml), and the cofactors FMN, FAD, and BH4. We found that both IL-1beta and TNF-alpha could independently activate cytosolic NF-kappaB, direct its translocation into the nucleus, and induce iNOS monomer synthesis. In addition, different combinations of cytokines produced synergistic amounts of iNOS monomers. Exogenous BH4 (0.1 microM) had no impact on NO production induced by cytokine combinations that included IL-1beta, but significantly enhanced NO production in the presence of INF-gamma and TNF-alpha, and allowed TNF-alpha independently to produce NO. We conclude that there are at least three mechanisms of synergistic cytokine-induced NO production: (1) the biosynthesis of iNOS monomer due to nonlinear interactions by transcription factors, (2) synergistic cytosolic activation of NF-kappaB, and (3) parallel biosynthesis of BH4 in the presence of cytokine combinations that include IL-1beta.
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- 2001
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45. Inhibition by clonidine of the carbachol-induced tension development and nonselective cationic current in guinea pig ileal myocytes.
- Author
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Chung S, Kwon S, Kim Y, Ahn D, Lee Y, and Nam T
- Subjects
- Adrenergic alpha-Antagonists pharmacology, Animals, Calcium Channels drug effects, Female, Guinea Pigs, Ileum cytology, Ileum drug effects, Imidazoline Receptors, In Vitro Techniques, Male, Muscle Contraction drug effects, Muscle, Smooth cytology, Muscle, Smooth drug effects, Patch-Clamp Techniques, Potassium Channels, Voltage-Gated antagonists & inhibitors, Receptors, Adrenergic, alpha-2 drug effects, Receptors, Drug drug effects, Adrenergic alpha-Agonists pharmacology, Carbachol pharmacology, Clonidine pharmacology, Ileum physiology, Ion Channels antagonists & inhibitors, Muscarinic Agonists pharmacology, Muscle, Smooth physiology
- Abstract
Effects of clonidine, an imidazoline derivative as well as alpha2-adrenoceptor agonist, on carbachol (CCh)-evoked contraction in guinea pig ileal smooth muscle were studied using isometric tension recording. To investigate the cellular mechanisms of the inhibitory effect of clonidine, its effects on CCh-evoked nonselective cationic current (I(CCh)), voltage-dependent Ca2+ current (I(Ca)) and voltage-dependent K+ current (I(K)) was also studied using patch-clamp recording techniques in single ileal cells. Clonidine inhibited the contraction evoked by CCh (1 microM) in a concentration-dependent manner with an IC50 valve of 61.7 +/- 2.5 microM. High K+ (40 mM)-evoked contraction was only slightly inhibited even when clonidine was used at 300 microM. Externally applied clonidine inhibited I(CCh) dose-dependently with an IC50 of 42.0 +/- 2.6 microM. When applied internally via patch pipettes, clonidine was without effect. An I(CCh)-like current induced by GTPgammaS was also inhibited by bath application of clonidine. None of KU14R and BU224, both imidazoline receptor blockers, and yohimbine, an alpha2-adrenergic blocker, significantly affects the inhibitory effect of clonidine on I(CCh). Clonidine (300 microM) only slightly decreased membrane currents flowing through voltage-gated Ca2+ channels or K+ channels. These data indicate that clonidine relaxes smooth muscle contraction produced by muscarinic receptor activation and suggest that the effect of clonidine seems due mainly to inhibition of I(CCh) via acting directly on the involved cationic channel.
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- 2001
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46. Characterization of a novel gene expressed in neuromuscular tissues and centrosomes in Caenorhabditis elegans.
- Author
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Kwon S, Song WK, Park CS, and Ahnn J
- Subjects
- Amino Acid Sequence, Animals, Blotting, Northern, Blotting, Western, Gene Expression, Immunohistochemistry, In Situ Hybridization, Molecular Sequence Data, Physical Chromosome Mapping, Polymerase Chain Reaction, Sequence Homology, Amino Acid, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins, Centrosome chemistry, Membrane Proteins chemistry, Muscles chemistry, Nervous System chemistry
- Abstract
The nematode Caenorhabditis elegans has many advantages for studying gene function at the organism level. In particular, completion of the genome sequencing has made it feasible to study gene structure and function of both known and novel proteins. As a result of a database search for muscle-specific genes, a gene F43D9.1 was found which showed muscle-specific expression as revealed by the in situ hybridization pattern from the Expressed Sequence Tag (EST) database. A homology search of F43D9.1 protein sequences showed no significant homology with other known proteins, except that it showed very weak sequence similarity with the band 4.1 protein superfamily. Northern blot analysis reveals a single transcript 3.7 kb in size which is consistent with the predicted gene structure. The expression pattern of F43D9.1 was investigated using the gfp reporter gene, and it has shown to be expressed in neuronal cells including sensory neurons and interneurons in the head region. To further characterize F43D9.1, whole-mount immunostaining was performed with anti-F43D9.1 antibody, which showed specific signals in head neurons, body-wall muscle cells, some other unidentified neuronal cells, and centrosomes of the dividing cells during embryogenesis. Taken together with its predicted membrane topology, we speculate that the F43D9.1 gene, which encodes a novel transmembrane protein and contains a band 4.1-like domain, may function in neuromuscular cells, and may play an important role during cell division in C. elegans., (Copyright 2001 John Wiley & Sons, Ltd.)
- Published
- 2001
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47. Capsaicin-induced relaxation in rabbit coronary artery.
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Yeon D, Kwon S, Lee Y, Leem J, Nam T, and Ahn D
- Subjects
- 4-Aminopyridine pharmacology, Animals, Calcium metabolism, Capsaicin antagonists & inhibitors, Coronary Vessels physiology, Dinoprost pharmacology, Drug Interactions, Fluorescent Dyes chemistry, Fura-2 chemistry, In Vitro Techniques, Isometric Contraction drug effects, Isometric Contraction physiology, Muscle Relaxation physiology, Muscle, Smooth, Vascular physiology, Peptides pharmacology, Potassium Channel Blockers, Potassium Channels physiology, Rabbits, Ruthenium Red pharmacology, Capsaicin analogs & derivatives, Capsaicin pharmacology, Coronary Vessels drug effects, Fura-2 analogs & derivatives, Muscle Relaxation drug effects, Muscle, Smooth, Vascular drug effects
- Abstract
In the present study mechanism of inhibitory effects of capsaicin on the contractility of rabbit coronary artery were studied by measurement of isometric tension and intracellular Ca2+ concentration. Capsaicin (1 microM to 30 microM) relaxed the coronary artery pre-contracted with prostaglandin (PG) F2alpha (1 microM) in a concentration-dependent manner. The PGF2alpha-induced increase in intracellular Ca2+ concentration was also inhibited. The effects of capsaicin were readily reversed by washing capsaicin from the bath. Capsaicin-induced relaxation was not attenuated by pretreatment with capsazepine (1 microM), a blocker of vanilloid receptor or ruthenium red (1 microM), a blocker of non-selective cation channel. Previous exposure to a high concentration of capsaicin (100 microM) or repeated application of capsaicin did not eliminate the relaxation response to subsequent application of capsaicin. Increasing the external K+ concentration to 80 mM significantly attenuated the capsaicin-induced relaxation with simultaneous change in intracellular Ca2+ concentration. Pretreatment with iberiotoxin (100 nM), a blocker of Ca2+-activated K+ channel, only partially inhibited the capsaicin-induced relaxation. However, application of 4-aminopyridine (4-AP, 1 mM), a blocker of delayed rectifier K+ current significantly inhibited the capsaicin-induced relaxation with concomitant attenuation of the effect on intracellular Ca2+ concentration. These results indicate that capsaicin may have a direct relaxing effect on the smooth muscle contractility, and relaxation may be due to activation of the 4-AP-sensitive, delayed rectifier K+ channels in the rabbit coronary artery.
- Published
- 2001
- Full Text
- View/download PDF
48. Microinjection of arginine vasopressin into the central nucleus of amygdala suppressed nociceptive jaw opening reflex in freely moving rats.
- Author
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Ahn DK, Kim KH, Ju JS, Kwon S, and Park JS
- Subjects
- Adrenergic alpha-Antagonists pharmacology, Amygdala metabolism, Animals, Dose-Response Relationship, Drug, Electric Stimulation adverse effects, Electromyography drug effects, Male, Masticatory Muscles drug effects, Masticatory Muscles innervation, Masticatory Muscles physiology, Methysergide pharmacology, Microinjections, Movement drug effects, Movement physiology, Muscle Contraction drug effects, Muscle Contraction physiology, Naloxone pharmacology, Narcotic Antagonists pharmacology, Neurons drug effects, Neurons metabolism, Nociceptors cytology, Nociceptors metabolism, Pain drug therapy, Pain physiopathology, Phentolamine pharmacology, Rats, Rats, Sprague-Dawley, Reflex physiology, Serotonin Antagonists pharmacology, Amygdala drug effects, Arginine Vasopressin pharmacology, Nociceptors drug effects, Pain metabolism, Pain Measurement drug effects, Reflex drug effects
- Abstract
This study was performed to examine the antinociceptive effect after microinjection of arginine vasopressin (AVP) into the central nucleus of amygdala. We recorded the jaw opening reflex in freely moving rats. After injection of 0.2 or 0.4 nM AVP into the central nucleus of amygdala, digastric electromyogram (dEMG) was suppressed to 55 +/- 5% or 88 +/- 3 of the control. Artificial cerebrospinal fluid had no effects on the basal dEMG activity. V(1) vasopressin receptor antagonist blocked the suppressive effect produced by microinjection of 0.4 nM AVP from 53 +/- 3 to 81 +/- 3% of the control. However, V(2) vasopressin receptor antagonist did not affect changes in dEMG. We observed dEMG activity after intracerebroventricular injection of naloxone, methysergide, or phentolamine. All drugs did not affect the basal dEMG activity at our dose. Naloxone blocked the suppressive effect of 0.4 nM AVP from 42 +/- 4 to 79 +/- 5% of the control. Methysergide also inhibited the suppression of dEMG from 44 +/- 3 to 83 +/- 6% of the control. However, phentolamine, an alpha-adrenergic receptor antagonist, did not affect the suppression of dEMG. These results indicate AVP in the central nucleus of amygdala has potent analgesic effects in the orofacial area. The antinociception of central AVP seems to be mediated by opioid and serotonergic pathways.
- Published
- 2001
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49. Clinical spectrum of reversible posterior leukoencephalopathy syndrome.
- Author
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Kwon S, Koo J, and Lee S
- Subjects
- Adolescent, Adult, Brain Edema etiology, Child, Child, Preschool, Cyclosporine adverse effects, Diagnosis, Differential, Female, Follow-Up Studies, Hemosiderin metabolism, Humans, Lactic Acid metabolism, Male, Neurologic Examination, Remission, Spontaneous, Risk Factors, Syndrome, Blood-Brain Barrier physiology, Brain Edema diagnosis, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, Occipital Lobe pathology, Parietal Lobe pathology
- Abstract
Reversible posterior leukoencephalopathy syndrome is a recently recognized disorder with characteristic radiologic findings that mainly involve the white/gray matter of the parieto-occipital lobes. This complex syndrome is associated with cyclosporine A therapy or a variety of other conditions in which blood pressure rises acutely. Twelve patients from a variety of conditions who met the diagnostic criteria for this syndrome were studied. Interestingly, three of these patients had intra-abdominal neurogenic tumors, which have rarely been reported. Initial cranial magnetic resonance imaging scans revealed fairly symmetric areas of increased T(2) signal involving both white and gray matter of parieto-occipital lobes in the majority of the patients. However, the lesions were often located outside the parieto-occipital regions. Four patients had occipital region magnetic resonance spectroscopy during the acute phase, which revealed high lactate peak and normal N-acetyl aspartate/creatine and choline peaks. With appropriate treatment, most patients recovered from this syndrome and experienced almost complete resolution of brain lesions on follow-up magnetic resonance imaging. One patient, however, continued to have small residual hemosiderin deposits on a follow-up magnetic resonance imaging with neurologic sequellae. In conclusion, a better understanding of this complex syndrome may obviate unnecessary investigations and allow management of the associated problems in prompt and appropriate ways.
- Published
- 2001
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50. High-rate continuous production of lactic acid by Lactobacillus rhamnosus in a two-stage membrane cell-recycle bioreactor.
- Author
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Kwon S, Yoo IK, Lee WG, Chang HN, and Chang YK
- Subjects
- Fermentation, Glucose metabolism, Kinetics, Lactobacillus chemistry, Lactobacillus growth & development, Models, Biological, Bioreactors economics, Lactic Acid biosynthesis, Lactobacillus metabolism
- Abstract
It is important to produce L(+)-lactic acid at the lowest cost possible for lactic acid to become a candidate monomer material for promising biodegradable polylactic acid. In an effort to develop a high-rate bioreactor that provides high productivity along with a high concentration of lactic acid, the performance of membrane cell-recycle bioreactor (MCRB) was investigated via experimental studies and simulation optimization. Due to greatly increased cell density, high lactic acid productivity, 21.6 g L(-1) h(-1), was obtained in the reactor. The lactic acid concentration, however, could not be increased higher than 83 g/L. When an additional continuous stirred tank reactor (CSTR) was attached next to the MCRB a higher lactic acid concentration of 87 g/L was produced at significant productivity expense. When the two MCRBs were connected in series, 92 g/L lactic acid could be produced with a productivity of 57 g L(-1) h(-1), the highest productivity among the reports of L(+)-lactic acid that obtained lactic acid concentration higher than 85 g/L using glucose substrate. Additionally, the investigation of lactic acid fermentation kinetics resulted in a successful model that represents the characteristics of lactic acid fermentation by Lactobacillus rhamnosus. The model was found to be applicable to most of the existing data with MCRBs and was in good agreement with Levenspiel's product-inhibition model, and the Luedeking-Piret equation for product-formation kinetics appeared to be effective in representing the fermentation kinetics. There was a distinctive difference in the production potential of cells (cell-density-related parameter in Luedeking-Piret equation) as lactic acid concentration increases over 55 g/L, and this finding led to a more precise estimation of bioreactor performance., (Copyright 2001 John Wiley & Sons, Inc.)
- Published
- 2001
- Full Text
- View/download PDF
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