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Cormican LJ, Farooque S, Altmann DR, Lee TH. Improvements in an oral aspirin challenge protocol for the diagnosis of aspirin hypersensitivity. Clin Exp Allergy 2006; 35:717-22. [PMID: 15969660 DOI: 10.1111/j.1365-2222.2005.02261.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oral aspirin challenge (OAC) is used to confirm aspirin hypersensitivity (AHs) but there is no consensus on a standardized protocol. As a prior clinical history of adverse reactions to aspirin is poorly predictive of a positive result from formal aspirin challenge, many patients have an OAC performed. We retrospectively identified and prospectively validated how a 1-day OAC protocol could be modified, and patient selection improved, to deliver a safe and more efficient service. In a retrospective audit of 45 OACs using a 2 h dose interval, all reactions occurred within 90 min of the threshold dose. Forty OACs were then performed using a 90-min dose interval. This reduced the mean duration of a positive and negative OAC from 6 to 5 h and from 8 to 6 h, respectively. Histories of multiple manifestations of AHs were found in 91.6% (11) of those with asthma, 87.5% (7) with angiooedema, 70.6% (12) with rhinosinusitis, 63.6% (7) with chronic non-vasculitic urticaria and all with anaphylaxis, who developed a positive OAC. None of those with anaphylaxis, 8.3% (1) with asthma and 12.5% (1) with angiooedema, with a positive OAC, had a history of a single manifestation of AHs. The efficiency of an OAC service can safely be improved by reduction of the dose interval from 2 to 1 (1/2) h, and more targeted patient selection, as the likelihood of a positive OAC increases among patients with a history of asthma, angiooedoema or anaphylaxis with multiple manifestations of AHs.
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Xiang C, Fan XA, Lee TH. Face recognition using recursive Fisher linear discriminant. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2006; 15:2097-105. [PMID: 16900667 DOI: 10.1109/tip.2006.875225] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Fisher linear discriminant (FLD) has recently emerged as a more efficient approach for extracting features for many pattern classification problems as compared to traditional principal component analysis. However, the constraint on the total number of features available from FLD has seriously limited its application to a large class of problems. In order to overcome this disadvantage, a recursive procedure of calculating the discriminant features is suggested in this paper. The new algorithm incorporates the same fundamental idea behind FLD of seeking the projection that best separates the data corresponding to different classes, while in contrast to FLD the number of features that may be derived is independent of the number of the classes to be recognized. Extensive experiments of comparing the new algorithm with the traditional approaches have been carried out on face recognition problem with the Yale database, in which the resulting improvement of the performances by the new feature extraction scheme is significant.
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Zhao S, Putra AS, Tan KK, Panda SK, Lee TH. Intelligent compensation of friction, ripple, and hysteresis via a regulated chatter. ISA TRANSACTIONS 2006; 45:419-33. [PMID: 16856637 DOI: 10.1016/s0019-0578(07)60222-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In this paper, a hybrid control scheme utilizing a PID feedback control with an additional regulated chatter signal is developed to compensate motion impeding influences such as the effects due to friction, force ripples, and hysteresis in linear piezoelectric motor. The regulated chatter signal is a pulse sequence superimposed on the PID control signal. It has a fixed amplitude, and a pulse width regulated via iterative learning control. As such, the scheme is expected to be useful for applications involving iterative motion sequences. An analysis of the closed-loop performance is presented in the paper. Simulation and experimental results are also furnished to demonstrate that the proposed control scheme can reduce tracking errors significantly.
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Kim HJ, Park SH, Lee TH, Nahm BH, Chung YH, Seo KH, Kim HY. Identification of Salmonella enterica serovar Typhimurium using specific PCR primers obtained by comparative genomics in Salmonella serovars. J Food Prot 2006; 69:1653-61. [PMID: 16865900 DOI: 10.4315/0362-028x-69.7.1653] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonella enterica serovar Typhimurium is a major foodborne pathogen throughout the world. Until now, the specific target genes for the detection and identification of serovar Typhimurium have not been developed. To determine the specific probes for serovar Typhimurium, the genes of serovar Typhimurium LT2 that were expected to be unique were selected with the BLAST (Basic Local Alignment Search Tool) program within GenBank. The selected genes were compared with 11 genomic sequences of various Salmonella serovars by BLAST. Of these selected genes, 10 were expected to be specific to serovar Typhimurium and were not related to virulence factor genes of Salmonella pathogenicity island or to genes of the O and H antigens of Salmonella. Primers for the 10 selected genes were constructed, and PCRs were evaluated with various genomic DNAs of Salmonella and non-Salmonella strains for the specific identification of Salmonella serovar Typhimurium. Among all the primer sets for the 10 genes, STM4497 showed the highest degree of specificity to serovar Typhimurium. In this study, a specific primer set for Salmonella serovar Typhimurium was developed on the basis of the comparison of genomic sequences between Salmonella serovars and was validated with PCR. This method of comparative genomics to select target genes or sequences can be applied to the specific detection of microorganisms.
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Loke TK, Mallett KH, Ratoff J, O'Connor BJ, Ying S, Meng Q, Soh C, Lee TH, Corrigan CJ. Systemic glucocorticoid reduces bronchial mucosal activation of activator protein 1 components in glucocorticoid-sensitive but not glucocorticoid-resistant asthmatic patients. J Allergy Clin Immunol 2006; 118:368-75. [PMID: 16890760 DOI: 10.1016/j.jaci.2006.04.055] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 04/28/2006] [Accepted: 04/28/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Overexpression of the transcriptional regulatory factor activator protein 1 might contribute to T-cell glucocorticoid (GC) refractoriness in GC-resistant asthma. OBJECTIVE We sought to address the hypothesis that clinically GC-resistant asthma is accompanied by failure of systemic GCs to inhibit phosphorylation of c-jun and c-jun N-terminal kinase (JNK) in bronchial mucosal cells. METHODS We performed enumeration of total (CD45+) leukocytes and cells expressing c-fos and total and phosphorylated c-jun and JNK in bronchial biopsy sections from 9 GC-sensitive and 17 GC-resistant asthmatic patients taken before and after oral prednisolone (40 mg/1.72 m(2) body surface area daily for 14 days) using specific antibodies, immunohistochemistry, and image analysis. RESULTS At baseline, mean total (CD45+) mucosal leukocytes, total cells expressing phosphorylated c-jun and JNK, and mean percentages of cells in which these molecules were phosphorylated were similar in both groups, whereas mean total numbers of c-fos-immunoreactive cells were increased in the GC-resistant asthmatic subjects (P = .04). After prednisolone, the mean total cells expressing phosphorylated c-jun and JNK and the mean percentages of cells in which these molecules were phosphorylated were significantly reduced in the GC-sensitive (P < or = .02) but not the GC-resistant asthmatic subjects. Mean total CD45+ leukocytes and c-fos-immunoreactive cells were not significantly altered in either group. CONCLUSION Clinical GC responsiveness in asthma is accompanied by reduced phosphorylation of bronchial mucosal c-jun and JNK, a phenomenon not seen in resistant patients. CLINICAL IMPLICATIONS Dysregulation of activator protein 1 activation leading to clinical GC resistance might reflect identifiable environmental influences and is a target for future therapy.
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Lee YH, Kim TK, Suh SI, Kwon BJ, Lee TH, Kwon OK, Han MH, Lee NJ, Kim JH, Seol HY. Simultaneous Bilateral Carotid Stenting under the Circumstance of Neuroprotection Device. A Retrospective Analysis. Interv Neuroradiol 2006; 12:141-8. [PMID: 20569566 DOI: 10.1177/159101990601200208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 05/15/2006] [Indexed: 11/16/2022] Open
Abstract
SUMMARY In this study, in order to evaluate the feasibility and outcomes of simultaneous bilateral carotid artery stenting (CAS) with the use of neuroprotection in symptomatic patients, we conducted a retrospective analysis of 27 patients (19 men, eight women; median age, 69.2 years), all of whom had been scheduled to undergo bilateral CAS in a single setting. All patients presented with severe atherosclerotic bilateral carotid stenosis (> 50% for symptomatic side, > 80% for asymptomatic side), exhibiting symptoms of either a cerebrovascular accident or of a transient ischemic attack on at least one side. 48 arteries were treated with self-expandable stents. Neuroprotection devices were utilized for bilateral CAS in 11 patients, and in 16 unilateral CAS patients. We did not perform the second procedure in six patients, in cases in which a patient exhibited (a) hemodynamic instability, (b) a new neurological impairment, or (c) restlessness after a prolonged time for the first CAS. The second procedure was postponed in a staged manner. We achieved a mean residual stenosis of 8.1 +/- 5.0 % in the treated lesions. The mean procedural time for bilateral CAS was three hours and 18 minutes. 17 patients (63%) developed transient bradycardia during the balloon dilatation of one or both of the relevant arteries. Three patients (11%) exhibited persistent bradycardia and hypotension, which required the administration of intravenous vasopressors for several days (2~7 days). None of the patients ultimately required pacemakers, or any further therapy. Two of the patients (7%) developed transient ischemic attack during the periprocedural period, but recovered completely. One patient developed a new minor stroke after the first procedure, and the second procedure was delayed in a staged manner.We observed no periprocedural deaths, major strokes, or myocardial infarctions, nor did we detect any cases of hyperperfusion syndrome within 30 days. In summary, simultaneous bilateral CAS with neuroprotection can be performed in a single setting without increased concerns with regard to hyperperfusion syndrome, hemodynamic instability, thrombo-embolism, or procedure time, when the first CAS has been safely completed with no evidence of complications in a wellmanaged procedure time.
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Chan V, Burgess JK, Ratoff JC, O'connor BJ, Greenough A, Lee TH, Hirst SJ. Extracellular matrix regulates enhanced eotaxin expression in asthmatic airway smooth muscle cells. Am J Respir Crit Care Med 2006; 174:379-85. [PMID: 16709936 DOI: 10.1164/rccm.200509-1420oc] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Altered airway smooth muscle (ASM) function and enrichment of the extracellular matrix (ECM) with fibronectin and collagen are key features of asthma. Previously, we have reported these ECM proteins enhance ASM synthetic function. OBJECTIVE We compared ASM cultured from endobronchial biopsies from subjects with and without asthma to assess if asthmatic cells were hypersecretory and determined whether the underlying mechanism involved autocrine ECM production. METHODS AND MEASUREMENTS Cells from subjects with and without asthma were cultured on plastic or in plates precoated with ECM proteins. Cytokine production was evaluated by enzyme-linked immunosorbent assay and by reverse transcriptase-polymerase chain reaction. Function-blocking integrin antibodies were used to identify integrin involvement. RESULTS Baseline eotaxin and its production after stimulation with interleukin (IL)-13, IL-1beta, or tumor necrosis factor-alpha was increased (2.5- to 6.0-fold) in ASM cells cultured from subjects with asthma compared with healthy subjects. When seeded on ECM from asthmatic ASM, IL-13-dependent eotaxin release from healthy or asthmatic ASM was enhanced compared with culture on healthy ECM. The ECM substrates fibronectin and type I collagen each enhanced IL-13-dependent eotaxin release, and Western immunoblot indicated that fibronectin expression was higher in asthmatic ASM cells. Integrin-blocking antibodies revealed that alpha5beta1 was required for more than 50% of the enhanced IL-13-dependent eotaxin release by ASM cells from subjects with asthma, whereas alpha2beta1 or alphavbeta3 neutralization lacked effect. CONCLUSION The data indicate that ASM cells cultured from subjects with asthma are hypersecretory compared with cells from healthy donors and that autocrine fibronectin secretion acting via alpha5beta1 in part underlies this effect.
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Huh KC, Lee TH, Kim SM, Im EH, Choi YW, Kim BK, Jung DJ, Choi WJ, Kang YW. Intussuscepted sigmoid colonic lipoma mimicking carcinoma. Dig Dis Sci 2006; 51:791-5. [PMID: 16615005 DOI: 10.1007/s10620-006-3208-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Accepted: 04/04/2005] [Indexed: 02/08/2023]
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Ying S, Meng Q, Scadding G, Parikh A, Corrigan CJ, Lee TH. Aspirin-sensitive rhinosinusitis is associated with reduced E-prostanoid 2 receptor expression on nasal mucosal inflammatory cells. J Allergy Clin Immunol 2006; 117:312-8. [PMID: 16461132 DOI: 10.1016/j.jaci.2005.10.037] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 10/14/2005] [Accepted: 10/26/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Impaired braking of inflammatory cell cysteinyl leukotriene production by prostaglandin (PG) E(2) has been implicated in the pathogenesis of aspirin exacerbated airways disease, but the mechanism is obscure. PGE(2) acts via G-protein-coupled receptors, E-prostanoid (EP)(1-4,) but there is little information on the expression of PGE(2) receptors in this condition. OBJECTIVE To address the hypothesis that expression of 1 or more EP receptors on nasal mucosal inflammatory cells is deficient in patients with aspirin-sensitive compared with nonaspirin-sensitive polypoid rhinosinusitis. METHODS By using specific antibodies, immunohistochemistry, and image analysis, we measured the expression of EP(1-4) in nasal biopsies from patients with aspirin-sensitive (n = 12) and nonaspirin-sensitive (n = 10) polypoid rhinosinusitis and normal controls (n = 9). Double-staining was used to phenotype inflammatory leukocytes expressing EP(1-4). RESULTS Global mucosal expression of EP(1) and EP(2), but not EP(3) or EP(4), immunoreactivity was significantly elevated in aspirin-sensitive and nonaspirin-sensitive rhinosinusitis compared with controls (P < .03). This was attributable principally to elevated expression on tubulin(+) epithelial cells and Mucin 5 subtypes A and B (Muc-5AC(+)) goblet cells. In contrast, the percentages of neutrophils, mast cells, eosinophils, and T cells expressing EP(2), but not EP(1), EP(3), or EP(4), were significantly reduced (P < or = .04) in the aspirin-sensitive compared with nonaspirin-sensitive patients. CONCLUSION The data suggest a possible role for PGE(2) in mediating epithelial repair in rhinitis and asthma. Because PGE(2) exerts a range of inhibitory actions on inflammatory leukocytes via the EP(2) receptor, its reduced expression in aspirin-sensitive rhinosinusitis may be partly responsible for the increased inflammatory infiltrate and production of cysteinyl leukotrienes that characterize aspirin-sensitive disease.
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Lin YM, Chen CN, Yoshinaga T, Tsai SC, Shen ID, Lee TH. Short-term effects of hyposmotic shock on Na+/K+-ATPase expression in gills of the euryhaline milkfish, Chanos chanos. Comp Biochem Physiol A Mol Integr Physiol 2006; 143:406-15. [PMID: 16459117 DOI: 10.1016/j.cbpa.2005.12.031] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 12/21/2005] [Accepted: 12/21/2005] [Indexed: 10/25/2022]
Abstract
Changes in expression of gill Na+/K+ -ATPase (NKA) on a short-term (96 h) time-course following hyposmotic shock (direct transfer to fresh water) of the euryhaline, marine milkfish were studied on gene, protein, and cell levels in this paper. Plasma osmolality and [Na+] responded with rapid declines in 3 h post-transfer yet, thereafter, remained constant. Plasma [Cl-] gradually fell to a significantly lower level at 6 h post-transfer. Gills responded to hyposmotic shock by a dual phase enhancement of NKA activity and protein abundance; (a) Before 24 h: NKA activity increased as early as 3 h and reached a maximum level from 6 to 12 h post-transfer coincided with the sustained lower levels of plasma osmolality, [Na+], and [Cl-] since 3 h post-transfer. This was followed by a gradual rise in alpha-subunit protein levels that peaked at 12 h post-transfer. Meanwhile, alpha-mRNA of NKA did no show significant change. (b) After 24 h: NKA activity as well as the amounts of alpha-subunit mRNA and protein increased significantly. Direct freshwater transfer induced a prompt and significant decrease of NKA immunoreactive (NKIR) cell abundance in filaments before 24 h, followed by a significant increase after 24 h due to their development in filaments and lamellae. Increased number of NKIR cells after 24 h of hyposmotic shock may occur in conjunction with rise of NKA activity as well as alpha-subunit mRNA and protein abundance. In conclusion, milkfish is able to avoid an excessive drop in plasma ions immediately upon hyposmotic shock and maintain plasma ions on a marginal lower level in fresh water. Notably, the initial increase in NKA activity (adjustive phase; 3-12 h) and delayed increase in NKA mRNA and protein abundance (regulatory phase; 48-96 h) indicate the importance of a higher level of the gill enzyme in milkfish upon hyposmotic shock.
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Ko JH, Lee SH, Kim JR, Kim YJ, Hwang IS, Lee TH, Kim CW. Monitoring of pH inhibition on microbial activity in a continuous flow reactor by pseudo toxic concentration (C(PT)) concept and time delay model. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 53:367-73. [PMID: 16722088 DOI: 10.2166/wst.2006.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The pseudo toxic concentration (C(PT)) concept was introduced as a quantification method to describe pH as an inhibitor concentration. In this research, the applicability of the C(PT) concept model for the detection of pH inhibitions was expanded for a continuous flow activated sludge reactor. A pilot equipped with an inhibition detection system was installed. Inhibitory wastewater was injected for 1 h and the relative activity was calculated by the maximum respiration rate. At the same time, the coefficients for the C(PT) concept model were estimated. At the dynamic conditions, the estimated relative activity by the C(PT) concept model showed time lag compared to the measured one. However, the time lag problem was successfully resolved by introducing a transfer function into the C(PT) concept model. The C(PT) concept model combined with a transfer function (C(PT) + TF model) successfully tracked the variation of the relative activity under dynamic conditions. The C(PT) + TF model could detect 50% inhibition faster than the respirometry based method by approximately 10 min. Moreover, it had additional advantages such as being inexpensive, easy to install and simple to operate. In conclusion, the C(PT) + TF model was an effective and convenient detection method of pH inhibition.
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Lee SH, Ko JH, Poo KM, Lee TH, Woo HJ, Kim CW. Practical approach to parameter estimation for ASM3+ bio-P module applied to five-stage step-feed EBPR process. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 53:139-48. [PMID: 16532744 DOI: 10.2166/wst.2006.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Various parameter optimization approaches to a five-stage step-feed EBPR process modeled using the ASM3+bio-P module were examined. Five stoichiometric (Y(STO,NO), Y(H,O2, Y(H,NO,) Y(PAO,O2), Y(PO4)) and seven kinetic parameters (k(STO), eta(NO), b(H), mu(max),PAO, q(PHA), q(PP), mu(max),A) were estimated. The optimization approaches could be classified based on the data sources (batch experiments or CSTR operation data) and the number of target variables used in calculating the objective function. Optimized parameter values obtained by each approach were validated with CSTR operation data that were not used for parameter optimization. The results showed that the parameter optimization only with batch experimental results could not be directly applied to CSTR operation data. ASM3 + bio-P module parameters could be finely optimized only with CSTR operation data when sufficient target variables for objective function calculation were applied. When the number of target variables was increased, prediction performance was significantly improved. Once optimized, the model was able to predict the characteristic features of the five-stage step-feed process; namely, a high PAO yield, fast PAO growth, fast X(pp) storage, slow X(STO) and X(PHA) storage.
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Lee SH, Ko JH, Kim JR, Kim YJ, Lee JJ, Kim CW, Lee TH. Identification of the adverse effect of nitrate on the phosphate release rate and improvement of EBPR process models. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 53:115-23. [PMID: 16722061 DOI: 10.2166/wst.2006.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The adverse effect of nitrate on the phosphate release rate in the anaerobic phase was observed and was hardly explainable with conventional EBPR process models. Four possible mechanisms were proposed including substrate competition, reduced fermentation, parallel reaction and sequential reaction. Batch experiments were designed and conducted to identify the dominant mechanism. Results showed that the sequential reaction was the only possible mechanism where only denitrification occurred if any nitrate existed in the anaerobic phase. Then the phosphate release following after the nitrate was completely removed. Nitrate inhibition effect was added into the PHA storage rate to incorporate the sequential reaction in the conventional ASM3 plus EAWAG bio-P module (ASM3 + P). Nitrate inhibition coefficient, K(I,NO,PAO) was found to be as low as 0.05 mg/L. This correlated well with experimental observation where no also meant that the anaerobic compartment of a continuous flow reactor could be seriously affected by the residual nitrate contained in the sludge recycle flow. This phenomenon caused overestimation of the phosphate uptake rate and consequently underestimation of PO4(3-) -P concentration. This problem was resolved by incorporation of a nitrate inhibition term in the ASM3 + P for more accurate simulation of the EBPR process.
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Huang SN, Tan KK, Lee TH. Nonlinear Adaptive Control of Interconnected Systems Using Neural Networks. ACTA ACUST UNITED AC 2006; 17:243-6. [PMID: 16526492 DOI: 10.1109/tnn.2005.857948] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this letter, we solve the problem of decentralized adaptive asymptotic tracking for a class of large scale systems with significant nonlinearities and uncertainties. Neural networks (NNs) are used as a control part to cancel the effect of the unknown nonlinearity. Semiglobal asymptotic stability results are obtained and the tracking error converges to zero.
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Lee TH, Byun IG, Kim YO, Hwang IS, Park TJ. Monitoring biodegradation of diesel fuel in bioventing processes using in situ respiration rate. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 53:263-72. [PMID: 16722077 DOI: 10.2166/wst.2006.131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
An in situ measuring system of respiration rate was applied for monitoring biodegradation of diesel fuel in a bioventing process for bioremediation of diesel contaminated soil. Two laboratory-scale soil columns were packed with 5 kg of soil that was artificially contaminated by diesel fuel as final TPH (total petroleum hydrocarbon) concentration of 8,000 mg/kg soil. Nutrient was added to make a relative concentration of C:N:P = 100:10:1. One soil column was operated with continuous venting mode, and the other one with intermittent (6 h venting/6 h rest) venting mode. On-line O2 and CO2 gas measuring system was applied to measure O2 utilisation and CO2 production during biodegradation of diesel for 5 months. Biodegradation rate of TPH was calculated from respiration rate measured by the on-line gas measuring system. There were no apparent differences between calculated biodegradation rates from two columns with different venting modes. The variation of biodegradation rates corresponded well with trend of the remaining TPH concentrations comparing other biodegradation indicators, such as C17/pristane and C18/phytane ratio, dehydrogenase activity, and the ratio of hydrocarbon utilising bacteria to total heterotrophic bacteria. These results suggested that the on-line measuring system of respiration rate would be applied to monitoring biodegradation rate and to determine the potential applicability of bioventing process for bioremediation of oil contaminated soil.
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Xystrakis E, Kusumakar S, Boswell S, Peek E, Urry Z, Richards DF, Adikibi T, Pridgeon C, Dallman M, Loke TK, Robinson DS, Barrat FJ, O'Garra A, Lavender P, Lee TH, Corrigan C, Hawrylowicz CM. Reversing the defective induction of IL-10-secreting regulatory T cells in glucocorticoid-resistant asthma patients. J Clin Invest 2005; 116:146-55. [PMID: 16341266 PMCID: PMC1307558 DOI: 10.1172/jci21759] [Citation(s) in RCA: 446] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Accepted: 10/11/2005] [Indexed: 12/15/2022] Open
Abstract
We previously reported that human CD4+ Tregs secrete high levels of IL-10 when stimulated in the presence of dexamethasone and calcitriol (vitamin D3). We now show that following stimulation by allergen, IL-10-secreting Tregs inhibit cytokine secretion by allergen-specific Th2 cells in an IL-10-dependent manner. A proportion of patients with severe asthma fail to demonstrate clinical improvement upon glucocorticoid therapy, and their asthma is characterized as glucocorticoid resistant (SR, abbreviation derived from "steroid resistant"). Dexamethasone does not enhance secretion of IL-10 by their CD4+ T cells. Addition of vitamin D3 with dexamethasone to cultures of SR CD4+ T cells enhanced IL-10 synthesis to levels observed in cells from glucocorticoid-sensitive patients cultured with dexamethasone alone. Furthermore, pretreatment with IL-10 fully restored IL-10 synthesis in these cells in response to dexamethasone. Vitamin D3 significantly overcame the inhibition of glucocorticoid-receptor expression by dexamethasone while IL-10 upregulated glucocorticoid-receptor expression by CD4+ T cells, suggesting potential mechanisms whereby these treatments may overcome poor glucocorticoid responsiveness. We show here that administration of vitamin D3 to healthy individuals and SR asthmatic patients enhanced subsequent responsiveness to dexamethasone for induction of IL-10. This strongly suggests that vitamin D3 could potentially increase the therapeutic response to glucocorticoids in SR patients.
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Ying S, O'Connor B, Ratoff J, Meng Q, Mallett K, Cousins D, Robinson D, Zhang G, Zhao J, Lee TH, Corrigan C. Thymic stromal lymphopoietin expression is increased in asthmatic airways and correlates with expression of Th2-attracting chemokines and disease severity. THE JOURNAL OF IMMUNOLOGY 2005; 174:8183-90. [PMID: 15944327 DOI: 10.4049/jimmunol.174.12.8183] [Citation(s) in RCA: 620] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thymic stromal lymphopoietin (TSLP) is said to increase expression of chemokines attracting Th2 T cells. We hypothesized that asthma is characterized by elevated bronchial mucosal expression of TSLP and Th2-attracting, but not Th1-attracting, chemokines as compared with controls, with selective accumulation of cells bearing receptors for these chemokines. We used in situ hybridization and immunohistochemistry to examine the expression and cellular provenance of TSLP, Th2-attracting (thymus and activation-regulated chemokine (TARC)/CCL17, macrophage-derived chemokine (MDC)/CCL22, I-309/CCL1) and Th1-attracting (IFN-gamma-inducible protein 10 (IP-10)/CXCL10, IFN-inducible T cell alpha-chemoattractant (I-TAC)/CXCL11) chemokines and expression of their receptors CCR4, CCR8, and CXCR3 in bronchial biopsies from 20 asthmatics and 15 normal controls. The numbers of cells within the bronchial epithelium and submucosa expressing mRNA for TSLP, TARC/CCL17, MDC/CCL22, and IP-10/CXCL10, but not I-TAC/CXCL11 and I-309/CCL1, were significantly increased in asthmatics as compared with controls (p = 0.018). TSLP and TARC/CCL17 expression correlated with airway obstruction. Although the total numbers of cells expressing CCR4, CCR8, and CXCR3 did not significantly differ in the asthmatics and controls, there was evidence of selective infiltration of CD4(+)/CCR4(+) T cells in the asthmatic biopsies which correlated with TARC and MDC expression and airway obstruction. Epithelial cells, endothelial cells, neutrophils, macrophages, and mast cells were significant sources of TSLP and chemokines. Our data implicate TSLP, TARC/CCL17, MDC/CCL22, and IP-10/CXCL10 in asthma pathogenesis. These may act partly through selective development and retention, or recruitment of Th2 cells bearing their receptors.
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Dennis SM, Altmann DR, Lee TH. Increase in daytime symptoms is a sensitive and specific criterion for predicting corticosteroid-treated exacerbations in a clinical asthma trial. Clin Exp Allergy 2005; 35:308-12. [PMID: 15784108 DOI: 10.1111/j.1365-2222.2005.02178.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND To determine which diary card variables are the most predictive for administration of additional courses of corticosteroids using the TRUST (The Regular Use of Salbutamol Trial) data set. METHODS Logistic regression models were used to identify the extent to which a change in diary card variable affected the odds ratio (OR) for administering a course of oral or increased inhaled corticosteroids. The complete TRUST diary card data were used with over 200,000 days of diary card observations from 983 mild to moderate asthmatic subjects. RESULTS An increase in daytime symptoms of 1-5 U over baseline was associated with an increase in the OR for starting all types of corticosteroids from two- to 60-fold. CONCLUSIONS These results indicate that an increase in daytime symptoms of two or more over baseline strongly predicts the administration of additional corticosteroids. The results have significant implications for both clinical practice and design of clinical trials in asthma.
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Candiano G, Bruschi M, Pedemonte N, Caci E, Liberatori S, Bini L, Pellegrini C, Viganò M, O'Connor BJ, Lee TH, Galietta LJV, Zegarra-Moran O. Gelsolin secretion in interleukin-4-treated bronchial epithelia and in asthmatic airways. Am J Respir Crit Care Med 2005; 172:1090-6. [PMID: 16100010 DOI: 10.1164/rccm.200409-1185oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE The airway surface liquid, the thin layer of liquid covering the airways, is essential for mucociliary clearance and as a barrier against microbial and other noxious agents. Proteins secreted into the airway surface liquid by epithelial and nonepithelial cells may be important in innate immunity and to improve the fluidity of mucous secretions. OBJECTIVES We aimed to identify proteins specifically secreted into the airway surface liquid by human bronchial epithelial cells, in resting conditions and after treatment with interleukin 4 (IL-4), a cytokine released in asthma. METHODS AND MAIN RESULTS By using a proteomics approach, we found that one of the most abundant proteins was gelsolin, which breaks down actin filaments. Gelsolin mRNA and protein secretion were increased threefold in the airway surface liquid of epithelia treated with IL-4. These results were confirmed at the functional level by measuring actin depolymerization using a fluorescence assay. Gelsolin protein was also upregulated in the airways of subjects with asthma. CONCLUSIONS Our findings indicate that gelsolin is released by epithelial cells into the airways and that its secretion is increased by IL-4 in vitro. In addition, we found that the concentration of both IL-4 and gelsolin were raised in the bronchoalveolar lavage of patients with asthma. These results suggest that gelsolin might improve the fluidity of airway surface liquid in asthma by breaking down filamentous actin that may be released in large amounts by dying cells during inflammation.
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Byun YH, Lee MH, Kim SS, Kim H, Chang HK, Lee TH, Jang MH, Shin MC, Shin MS, Kim CJ. Treadmill running promotes functional recovery and decreases brain-derived neurotrophic factor mRNA expression following sciatic crushed nerve injury in rats. J Sports Med Phys Fitness 2005; 45:222-8. [PMID: 16355085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
AIM Peripheral nerve injuries are commonly encountered clinical problems and often result in severe functional deficits. In the present study, the effects of treadmill running on the recovery rate of locomotor function and the expression of brain-derived neurotrophic factor (BDNF) mRNA following sciatic crushed nerve injury in rats were investigated. METHODS EXPERIMENTAL DESIGN Comparative investigation was performed over 14 days. SETTING Experimental animal laboratory. PARTICIPANTS 24 male Sprague-Dawley rats weighing 200+/-10 g. Animals were randomly assigned into 3 groups: the sham-operation group, the sciatic nerve injury group, and the sciatic nerve injury and running group. INTERVENTIONS The right sciatic nerve was crushed for 30 s using a surgical clip. Rats of the running group were made to run on a treadmill for 30 min once a day for 12 consecutive days. MEASURES Functional recovery was analyzed using a walking track analysis which can be quantified with the sciatic function index (SFI) and BDNF mRNA expression was analyzed using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS Sciatic crushed nerve injury showed characteristic gait changes showing decrease of SFI value and treadmill running significantly enhanced the SFI value. The level of BDNF mRNA expression was increased following sciatic crushed nerve injury and treadmill running significantly suppressed the sciatic nerve injury-induced increment of BDNF mRNA expression. CONCLUSIONS It can be suggested that treadmill running after peripheral nerve injury is effective in the functional recovery by inhibition on the over-expression of BDNF mRNA.
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Peek EJ, Richards DF, Faith A, Lavender P, Lee TH, Corrigan CJ, Hawrylowicz CM. Interleukin-10-secreting "regulatory" T cells induced by glucocorticoids and beta2-agonists. Am J Respir Cell Mol Biol 2005; 33:105-11. [PMID: 15845862 DOI: 10.1165/rcmb.2005-0100oc] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Greater clinical benefit in controlling the symptoms of asthma is frequently observed through combining moderate doses of inhaled glucocorticoids together with long-acting beta(2)-agonists, as compared with increasing glucocorticoid dosage alone. To address in vitro whether glucocorticoids plus beta(2)-agonists, compared with glucocorticoids alone, have greater inhibitory activity on CD4+ T cell responses to allergen, peripheral blood CD4+ T cell responses to allergen were compared in the presence or absence of the glucocorticoid fluticasone proprionate and the short- and long-acting beta(2)-agonists salbutamol and salmeterol, respectively. Fluticasone proprionate inhibited interleukin (IL)-5 and IL-13 and enhanced IL-10 synthesis in allergen-stimulated cultures in a concentration-dependent manner. Salmeterol, but not salbutamol, inhibited IL-5 and IL-13 and enhanced IL-10 synthesis in these cultures. When used in combination the two drugs demonstrated an additive effect on this pattern of cytokine production. Allergen-specific T cell lines induced in the presence of salmeterol and fluticasone proprionate inhibited IL-5 and IL-13 production by allergen-specific Th2 cell lines in an IL-10-dependent manner. Thus fluticasone proprionate and salmeterol increased IL-10 and reduced Th2 cytokine synthesis additively in allergen stimulated human CD4+ T cells.
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Chang EJ, Lee TH, Mun KC, Kim HC, Suh SI, Bae JH, Kim SP, Cho KB, Hwang JS. Effects of polyhemoglobin-antioxidant enzyme complex on ischemia-reperfusion in kidney. Transplant Proc 2005; 36:1952-4. [PMID: 15518709 DOI: 10.1016/j.transproceed.2004.08.146] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION The kidney suffers ischemia-reperfusion (I/R) injury during transplantation. The purpose of the present study was to investigate the therapeutic effect of artificials cells on renal I/R injury through biochemical assays and histological examination. METHODS We prepared artificial cells using cross-linked hemoglobin (Hb), superoxide dismutase (SOD), and catalase. Normal male Sprague-Dawley rats were divided into 6 groups: the sham-operated control group, the group treated with polyHb,and the group treated with polyHb-SOD-catalase (PSC) (per groups were subjected to ischemia for 1 hour or 2 hours). After reperfusion for 4 hours, kidney and blood samples were obtained. RESULTS The levels of SOD and catalase in the PSC group were 15 and 50 times higher than those of the control group, respectively. In the polyHb group, the levels of blood urea nitrogen (BUN), serum creatinine, renal hydrogen peroxide, and renal malondialdehyde were increased. However, their levels were significantly decreased by PSC administration. Renal SOD activity did not show any significant changes in the polyHb group, but renal catalase activity was decreased by polyHb treatment in comparison with the control group. The activities of renal SOD and catalase were increased using PSC treatment. In the histological findings, the PSC group showed no evidence of acute tubular necrosis in proximal convoluted tubules; their microvilli and cytoplasmic microorganelles were relatively well preserved. CONCLUSIONS These results show that PSC effectively reduces renal damage via diminished oxygen free radical-mediated injury after I/R.
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Ying S, O'Connor BJ, Meng Q, Woodman N, Greenaway S, Wong H, Mallett K, Lee TH, Corrigan C. Expression of prostaglandin E(2) receptor subtypes on cells in sputum from patients with asthma and controls: effect of allergen inhalational challenge. J Allergy Clin Immunol 2005; 114:1309-16. [PMID: 15577828 DOI: 10.1016/j.jaci.2004.08.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Prostaglandin (PG) E 2 binds to 4 G-protein-coupled receptors designated EP 1 through EP 4 . Although PGE 2 plays an immunomodulatory role in asthma, there is little information on the expression of PGE 2 receptors in this disease. OBJECTIVE We hypothesized that profiles of E-prostanoid (EP) receptor expression are altered on asthmatic bronchial inflammatory cells in vivo and further altered by allergen challenge in vivo and proinflammatory mediators in vitro. METHODS The numbers and phenotypes of EP 1-4 immunoreactive induced sputum cells from atopic asthmatics (n = 13; before and 24 hours after allergen inhalational challenge) and normal controls (n = 9; 3 after saline challenge) and EP 1-4 expression on purified blood eosinophils from both groups (n = 4 for each) before and after stimulation with LPS and/or IL-5 in vitro were measured by using single and double immunocytochemistry. RESULTS Subsets of sputum cells of all phenotypes expressed all 4 EP receptors in both patients with asthma and controls. There were significantly greater numbers of macrophages expressing all 4 EP receptors and increased percentages of macrophages expressing EP 2 and EP 4 in patients with asthma compared with controls. Allergen bronchial challenge of patients with asthma was associated with a selective influx of eosinophils, but the percentages of these and other leukocytes expressing all 4 EP receptors were unchanged. Compared with sputum, only small percentages of peripheral blood eosinophils expressed each receptor, but this was increased by culture with exogenous IL-5 or LPS. CONCLUSION E-prostanoid receptor expression is increased on airway macrophages of patients with asthma at baseline and may be altered on eosinophils after allergen challenge in vivo in response to inflammatory stimuli.
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Corrigan CJ, Lee TH. Glucocorticoid Action and Resistance in Asthma. Allergol Int 2005. [DOI: 10.2332/allergolint.54.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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