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Stets EG, Lee CJ, Lytle DA, Schock MR. Increasing chloride in rivers of the conterminous U.S. and linkages to potential corrosivity and lead action level exceedances in drinking water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 613-614:1498-1509. [PMID: 28797521 PMCID: PMC7390064 DOI: 10.1016/j.scitotenv.2017.07.119] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/05/2017] [Accepted: 07/13/2017] [Indexed: 05/26/2023]
Abstract
Corrosion in water-distribution systems is a costly problem and controlling corrosion is a primary focus of efforts to reduce lead (Pb) and copper (Cu) in tap water. High chloride concentrations can increase the tendency of water to cause corrosion in distribution systems. The effects of chloride are also expressed in several indices commonly used to describe the potential corrosivity of water, the chloride-sulfate mass ratio (CSMR) and the Larson Ratio (LR). Elevated CSMR has been linked to the galvanic corrosion of Pb whereas LR is indicative of the corrosivity of water to iron and steel. Despite the known importance of chloride, CSMR, and LR to the potential corrosivity of water, monitoring of seasonal and interannual changes in these parameters is not common among water purveyors. We analyzed long-term trends (1992-2012) and the current status (2010-2015) of chloride, CSMR, and LR in order to investigate the short and long-term temporal variability in potential corrosivity of US streams and rivers. Among all sites in the trend analyses, chloride, CSMR, and LR increased slightly, with median changes of 0.9mgL-1, 0.08, and 0.01, respectively. However, urban-dominated sites had much larger increases, 46.9mgL-1, 2.50, and 0.53, respectively. Median CSMR and LR in urban streams (4.01 and 1.34, respectively) greatly exceeded thresholds found to cause corrosion in water distribution systems (0.5 and 0.3, respectively). Urbanization was strongly correlated with elevated chloride, CSMR, and LR, especially in the most snow-affected areas in the study, which are most likely to use road salt. The probability of Pb action-level exceedances (ALEs) in drinking water facilities increased along with raw surface water CSMR, indicating a statistical connection between surface water chemistry and corrosion in drinking water facilities. Optimal corrosion control will require monitoring of critical constituents reflecting the potential corrosivity in surface waters.
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Gorden PJ, Ydstie JA, Kleinhenz MD, Wulf LW, Gehring R, Lee CJ, Wang C, Coetzee JF. A study to examine the relationship between metritis severity and depletion of oxytetracycline in plasma and milk after intrauterine infusion. J Dairy Sci 2016; 99:8314-8322. [PMID: 27522419 DOI: 10.3168/jds.2016-10959] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 06/27/2016] [Indexed: 12/20/2022]
Abstract
Metritis is a frequent problem in postpartum dairy cows. Intrauterine therapy with the antimicrobial oxytetracycline (OTC) is often used, although this therapy has not been shown to be superior to systemic therapy. The objectives of this study were to (1) determine the plasma and milk concentrations of OTC following intrauterine infusion in postpartum dairy cows with varying degrees of metritis severity; (2) determine the depletion time of OTC in an attempt to provide veterinarians withdrawal guidelines, should they use this therapy; and (3) correlate metritis severity scores with OTC concentrations in plasma and milk. Our hypothesis was that cows with more severe metritis would have higher OTC concentrations in milk following intrauterine therapy. Thirty-two cows were selected to participate in the study after farm personnel had determined that they had metritis based on evaluation of vaginal discharge between 4 and 14 DIM, in accordance with the farm's treatment protocols. Metritis scores (1-4) were assigned based on a published scheme: 1 represented yellow-to-orange thick discharge or translucent mucus with no fetid smell; 2 represented blood-tinged vaginal mucus, slightly watery, with little or no fetid smell; 3 represented red to red/brown watery discharge with moderate fetid smell; and 4 represented red to red/brown watery discharge containing pieces of placenta and an intense fetid smell. Trial cows received a single treatment of 4g of OTC (approximately 6.7mg/kg) via intrauterine infusion. Blood samples were collected over 96h, and milk samples were collected before intrauterine therapy and 3 times a day for 4 d following infusion. Following treatment, OTC rapidly diffused to plasma and subsequently to milk. Maximum OTC concentrations in plasma and milk occurred within the first 24h following intrauterine infusion, and 25 of the 32 cows had detectable OTC concentrations in milk at 4 d after intrauterine infusion. Cows with clinical metritis (metritis severity scores of 3 or 4) at the initiation of treatment were significantly and positively correlated with higher milk OTC concentrations at the second [time (T)9 h; r=0.43], fourth (T25 h; r=0.42), and fifth milking following treatment (T33 h; r=0.38) compared with cows with normal vaginal discharge. We also observed a positive correlation between initial metritis score and milk maximum concentration (r=0.36) and milk area under the concentration curve (r=0.36). Given that intrauterine administration of OTC is an extra-label therapy, dairy producers should consult with their veterinarian to ensure that milk is being tested at or below the established tolerance for OTC. This will ensure that violative drug residues do not enter the human food supply.
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Chaudhry ZW, Doshi RS, Mehta AK, Jacobs DK, Vakil RM, Lee CJ, Bleich SN, Kalyani RR, Clark JM, Gudzune KA. A systematic review of commercial weight loss programmes' effect on glycemic outcomes among overweight and obese adults with and without type 2 diabetes mellitus. Obes Rev 2016; 17:758-69. [PMID: 27230990 PMCID: PMC5512172 DOI: 10.1111/obr.12423] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 03/25/2016] [Accepted: 03/25/2016] [Indexed: 01/09/2023]
Abstract
OBJECTIVE We examined the glycemic benefits of commercial weight loss programmes as compared with control/education or counselling among overweight and obese adults with and without type 2 diabetes mellitus (T2DM). METHODS We searched MEDLINE, Cochrane Database of Systematic Reviews, and references cited by individual programmes. We included randomized controlled trials of ≥12 weeks duration. Two reviewers extracted information on study design, population characteristics, interventions, and mean changes in haemoglobin A1c and glucose. RESULTS We included 18 randomized controlled trials. Few trials occurred among individuals with T2DM. In this population, Jenny Craig reduced A1c at least 0.4% more than counselling at 12 months, Nutrisystem significantly reduced A1c 0.3% more than counselling at 6 months, and OPTIFAST reduced A1c 0.3% more than counselling at 6 months. Among individuals without T2DM, few studies evaluated glycemic outcomes, and when reported, most did not show substantial reductions. DISCUSSION Few trials have examined whether commercial weight loss programmes result in glycemic benefits for their participants, particularly among overweight and obese individuals without T2DM. Jenny Craig, Nutrisystem and OPTIFAST show promising glycemic lowering benefits for patients with T2DM, although additional studies are needed to confirm these conclusions. © 2016 World Obesity.
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Lee PB, Kim YC, Lim YJ, Lee CJ, Choi SS, Park SH, Lee JG, Lee SC. Efficacy of Pulsed Electromagnetic Therapy for Chronic Lower Back Pain: A Randomized, Double-blind, Placebo-controlled Study. J Int Med Res 2016; 34:160-7. [PMID: 16749411 DOI: 10.1177/147323000603400205] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This randomized, double-blind, placebo-controlled clinical trial studied the effectiveness of pulsed electromagnetic therapy (PEMT) in patients with chronic lower back pain. Active PEMT ( n = 17) or placebo treatment ( n = 19) was performed three times a week for 3 weeks. Patients were assessed using a numerical rating scale (NRS) and revised Oswestry disability scores for 4 weeks after therapy. PEMT produced significant pain reduction throughout the observation period compared with baseline values. The percentage change in the NRS score from baseline was significantly greater in the PEMT group than the placebo group at all three time-points measured. The mean revised Oswestry disability percentage after 4 weeks was significantly improved from the baseline value in the PEMT group, whereas there were no significant differences in the placebo group. In conclusion, PEMT reduced pain and disability and appears to be a potentially useful therapeutic tool for the conservative management of chronic lower back pain.
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Au BC, Lee CJ, Lopez-Perez O, Foltz W, Felizardo TC, Wang JCM, Huang J, Fan X, Madden M, Goldstein A, Jaffray DA, Moloo B, McCart JA, Medin JA. Direct Lymph Node Vaccination of Lentivector/Prostate-Specific Antigen is Safe and Generates Tissue-Specific Responses in Rhesus Macaques. Biomedicines 2016; 4:biomedicines4010006. [PMID: 28536373 PMCID: PMC5344243 DOI: 10.3390/biomedicines4010006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 01/27/2016] [Accepted: 02/02/2016] [Indexed: 12/30/2022] Open
Abstract
Anti-cancer immunotherapy is emerging from a nadir and demonstrating tangible benefits to patients. A variety of approaches are now employed. We are invoking antigen (Ag)-specific responses through direct injections of recombinant lentivectors (LVs) that encode sequences for tumor-associated antigens into multiple lymph nodes to optimize immune presentation/stimulation. Here we first demonstrate the effectiveness and antigen-specificity of this approach in mice challenged with prostate-specific antigen (PSA)-expressing tumor cells. Next we tested the safety and efficacy of this approach in two cohorts of rhesus macaques as a prelude to a clinical trial application. Our vector encodes the cDNA for rhesus macaque PSA and a rhesus macaque cell surface marker to facilitate vector titering and tracking. We utilized two independent injection schemas demarcated by the timing of LV administration. In both cohorts we observed marked tissue-specific responses as measured by clinical evaluations and magnetic resonance imaging of the prostate gland. Tissue-specific responses were sustained for up to six months-the end-point of the study. Control animals immunized against an irrelevant Ag were unaffected. We did not observe vector spread in test or control animals or perturbations of systemic immune parameters. This approach thus offers an "off-the-shelf" anti-cancer vaccine that could be made at large scale and injected into patients-even on an out-patient basis.
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Lee CJ, Brown TT, Cheskin LJ, Choi P, Moran TH, Peterson L, Matuk R, Steele KE. Effects of meal composition on postprandial incretin, glucose and insulin responses after surgical and medical weight loss. Obes Sci Pract 2015; 1:104-109. [PMID: 27774253 PMCID: PMC5064622 DOI: 10.1002/osp4.17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/26/2015] [Accepted: 11/03/2015] [Indexed: 12/13/2022] Open
Abstract
Background Meal tolerance tests are frequently used to study dynamic incretin and insulin responses in the postprandial state; however, the optimal meal that is best tolerated and suited for hormonal response following surgical and medical weight loss has yet to be determined. Objective To evaluate the tolerability and effectiveness of different test meals in inducing detectable changes in markers of glucose metabolism in individuals who have undergone a weight loss intervention. Methods Six individuals who underwent surgical or medical weight loss (two Roux‐en‐Y gastric bypass, two sleeve gastrectomy and two medical weight loss) each completed three meal tolerance tests using liquid‐mixed, solid‐mixed and high‐fat test meals. The tolerability of each test meal, as determined by the total amount consumed and palatability, as well as fasting and meal‐stimulated glucagon‐like peptide, glucose‐dependent insulinotropic polypeptide, insulin and glucose were measured. Results Among the six individuals, the liquid‐mixed meal was better and more uniformly tolerated with a median meal completion rate of 99%. Among the four bariatric surgical patients, liquid‐mixed meal stimulated on average a higher glucagon‐like peptide (percent difference: 83.7, 89), insulin secretion (percent difference: 155.1, 158.7) and glucose‐dependent insulinotropic polypeptide (percent difference: 113.5, 34.3) compared with solid‐mixed and high‐fat meals. Conclusions The liquid‐mixed meal was better tolerated with higher incretin and insulin response compared with the high‐fat and solid‐mixed meals and is best suited for the evaluation of stimulated glucose homeostasis.
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Alarcon EI, Udekwu KI, Noel CW, Gagnon LBP, Taylor PK, Vulesevic B, Simpson MJ, Gkotzis S, Islam MM, Lee CJ, Richter-Dahlfors A, Mah TF, Suuronen EJ, Scaiano JC, Griffith M. Safety and efficacy of composite collagen-silver nanoparticle hydrogels as tissue engineering scaffolds. NANOSCALE 2015; 7:18789-18798. [PMID: 26507748 DOI: 10.1039/c5nr03826j] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering. The resulting hybrid materials at [AgNPs] < 0.4 μM retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 μM AgNPs in mice showed a reduction in the levels of IL-6 and other inflammation markers (CCL24, sTNFR-2, and TIMP1). Finally, an analysis of silver contents in implanted mice showed that silver accumulation primarily occurred within the tissue surrounding the implant.
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Mak WC, Cheung KY, Orban J, Lee CJ, Turner APF, Griffith M. Surface-Engineered Contact Lens as an Advanced Theranostic Platform for Modulation and Detection of Viral Infection. ACS APPLIED MATERIALS & INTERFACES 2015; 7:25487-94. [PMID: 26512953 DOI: 10.1021/acsami.5b08644] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have demonstrated an entirely new concept of a wearable theranostic device in the form of a contact lens (theranostic lens) with a dual-functional hybrid surface to modulate and detect a pathogenic attack, using a the corneal HSV serotype-1 (HSV-1) model. The theranostic lenses were constructed using a facile layer-by-layer surface engineering technique, keeping the theranostic lenses with good surface wettability, optically transparency, and nontoxic toward human corneal epithelial cells. The theranostic lenses were used to capture and concentrate inflammatory cytokines such as interleukin-1α (IL-1α), which is upregulated during HSV-1 reactivation, for sensitive, noninvasive diagnostics. The theranostic lens also incorporated an antiviral coating to serve as a first line of defense to protect patients against disease. Our strategy tackles major problems in tear diagnostics that are mainly associated with the sampling of a relatively small volume of fluid and the low concentration of biomarkers. The theranostic lenses show effective anti-HSV-1 activity and good analytical performance for the detection of IL-1α, with a limit of detection of 1.43 pg mL(-1) and a wide linear range covering the clinically relevant region. This work offers a new paradigm for "wearable" noninvasive healthcare devices combining "diagnosis" and "protection" against disease, while supporting patient compliance. We believe that this approach holds immense promise as a next-generation point-of-care and decentralized diagnostic/theranostic platform for a range of biomarkers.
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Mak WC, Olesen K, Sivlér P, Lee CJ, Moreno-Jimenez I, Edin J, Courtman D, Skog M, Griffith M. Controlled Delivery of Human Cells by Temperature Responsive Microcapsules. J Funct Biomater 2015; 6:439-53. [PMID: 26096147 PMCID: PMC4493523 DOI: 10.3390/jfb6020439] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 05/25/2015] [Accepted: 06/10/2015] [Indexed: 12/23/2022] Open
Abstract
Cell therapy is one of the most promising areas within regenerative medicine. However, its full potential is limited by the rapid loss of introduced therapeutic cells before their full effects can be exploited, due in part to anoikis, and in part to the adverse environments often found within the pathologic tissues that the cells have been grafted into. Encapsulation of individual cells has been proposed as a means of increasing cell viability. In this study, we developed a facile, high throughput method for creating temperature responsive microcapsules comprising agarose, gelatin and fibrinogen for delivery and subsequent controlled release of cells. We verified the hypothesis that composite capsules combining agarose and gelatin, which possess different phase transition temperatures from solid to liquid, facilitated the destabilization of the capsules for cell release. Cell encapsulation and controlled release was demonstrated using human fibroblasts as model cells, as well as a therapeutically relevant cell line-human umbilical vein endothelial cells (HUVECs). While such temperature responsive cell microcapsules promise effective, controlled release of potential therapeutic cells at physiological temperatures, further work will be needed to augment the composition of the microcapsules and optimize the numbers of cells per capsule prior to clinical evaluation.
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Gao A, Rizo PJ, Scaccabarozzi L, Lee CJ, Banine V, Bijkerk F. Photoluminescence-based detection of particle contamination on extreme ultraviolet reticles. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:063109. [PMID: 26133830 DOI: 10.1063/1.4922883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here, we propose a comparison-free inspection technique to detect particle contamination on the reticle of extreme ultraviolet (EUV) lithography systems, based on the photoluminescence spectral characteristics of the contaminant particles and their elemental composition. We have analyzed the spectra from different particles found on reticles in EUV lithographic systems and have determined the minimum detectable particle size: 25 nm for organic particles and 100 nm for Al particles. Stainless steel coatings (50 nm thick and 50 × 50 μm(2) in area) exhibit detectable photoluminescence, and the estimated minimum detectable particle is 2 μm.
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Lee YH, Lee CJ, Lee HS, Choe EY, Lee BW, Ahn CW, Cha BS, Lee HC, Balkau B, Kang ES. Comparing kidney outcomes in type 2 diabetes treated with different sulphonylureas in real-life clinical practice. DIABETES & METABOLISM 2015; 41:208-15. [PMID: 25687901 DOI: 10.1016/j.diabet.2015.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/20/2015] [Accepted: 01/22/2015] [Indexed: 11/29/2022]
Abstract
AIM Although several sulphonylureas are widely used in type 2 diabetes (T2D), their differential impacts on long-term major kidney outcomes remain unclear. This study aimed to investigate the effects of the two most commonly prescribed sulphonylureas, glimepiride and gliclazide, on kidney outcomes in patients with T2D. METHODS A total of 4486 patients treated with either glimepiride or gliclazide for more than 2 years were followed for up to 5.5 years (median: 4.7 years). A propensity score based on baseline characteristics was used to match 1427 patients treated with glimepiride with 1427 gliclazide-treated patients; incidences of end-stage renal disease (ESRD) and sustained doubling of creatinine to>132.6 μmol/L (1.5mg/dL) were also compared. RESULTS In the matched cohort with 12,122 person-years of follow-up, there was no significant difference between groups in risk of ESRD [hazard ratio (HR): 0.57, 95% confidence interval (CI): 0.29-1.12] or doubling of creatinine (HR: 0.74, 95% CI: 0.44-1.26), although there was a trend towards higher risks in the glimepiride group. Subgroup analyses showed that, compared with glimepiride, gliclazide was associated with a lower risk of doubling of creatinine in patients with preserved renal function (glomerular filtration rate ≥ 60 mL/min/1.73 m(2), HR: 0.21, 95% CI: 0.04-0.99) and good glycaemic control (HbA1c < 7%, HR: 0.35, 95% CI: 0.14-0.86), and in older subjects (≥ 62 years, HR: 0.52, 95% CI: 0.27-0.99). CONCLUSION In a real-life setting, there was no significant difference in clinical outcomes of kidney disease for patients treated with glimepiride vs gliclazide. However, gliclazide appeared to protect against renal complication progression in certain populations.
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Tengdelius M, Lee CJ, Grenegård M, Griffith M, Påhlsson P, Konradsson P. Synthesis and Biological Evaluation of Fucoidan-Mimetic Glycopolymers through Cyanoxyl-Mediated Free-Radical Polymerization. Biomacromolecules 2014; 15:2359-68. [DOI: 10.1021/bm5002312] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Lee CJ, Buznyk O, Kuffova L, Rajendran V, Forrester JV, Phopase J, Islam MM, Skog M, Ahlqvist J, Griffith M. Cathelicidin LL-37 and HSV-1 Corneal Infection: Peptide Versus Gene Therapy. Transl Vis Sci Technol 2014; 3:4. [PMID: 24932432 DOI: 10.1167/tvst.3.3.4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 04/13/2014] [Indexed: 12/17/2022] Open
Abstract
PURPOSE To evaluate the potential utility of collagen-based corneal implants with anti-Herpes Simplex Virus (HSV)-1 activity achieved through sustained release of LL-37, from incorporated nanoparticles, as compared with cell-based delivery from model human corneal epithelial cells (HCECs) transfected to produce endogenous LL-37. METHODS We tested the ability of collagen-phosphorylcholine implants to tolerate the adverse microenvironment of herpetic murine corneas. Then, we investigated the efficacy of LL-37 peptides delivered through nanoparticles incorporated within the corneal implants to block HSV-1 viral activity. In addition, LL-37 complementary DNA (cDNA) was transferred into HCECs to confer viral resistance, and their response to HSV-1 infection was examined. RESULTS Our implants remained in herpetic murine corneas 7 days longer than allografts. LL-37 released from the implants blocked HSV-1 infection of HCECs by interfering with viral binding. However, in pre-infected HCECs, LL-37 delayed but could not prevent viral spreading nor clear viruses from the infected cells. HCECs transfected with the LL-37 expressed and secreted the peptide. Secreted LL-37 inhibited viral binding in vitro but was insufficient to protect cells completely from HSV-1 infection. Nevertheless, secreted LL-37 reduced both the incidence of plaque formation and plaque size. CONCLUSION LL-37 released from composite nanoparticle-hydrogel corneal implants and HCEC-produced peptide, both showed anti-HSV-1 activity by blocking binding. However, while both slowed down virus spread, neither was able on its own to completely inhibit the viruses. TRANSLATIONAL RELEVANCE LL-37 releasing hydrogels may have potential utility as corneal substitutes for grafting in HSV-1 infected corneas, possibly in combination with LL-37 producing therapeutic cells.
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Ljunggren MK, Elizondo RA, Edin E, Olsen D, Merrett K, Lee CJ, Salerud G, Polarek J, Fagerholm P, Griffith M. Effect of Surgical Technique on Corneal Implant Performance. Transl Vis Sci Technol 2014; 3:6. [PMID: 24749003 DOI: 10.1167/tvst.3.2.6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 02/14/2014] [Indexed: 02/04/2023] Open
Abstract
PURPOSE Our aim was to determine the effect of a surgical technique on biomaterial implant performance, specifically graft retention. METHODS Twelve mini pigs were implanted with cell-free, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) cross-linked recombinant human collagen type III (RHCIII) hydrogels as substitutes for donor corneal allografts using overlying sutures with or without human amniotic membrane (HAM) versus interrupted sutures with HAM. The effects of the retention method were compared as well as the effects of collagen concentration (13.7% to 15% RHCIII). RESULTS All implanted corneas showed initial haze that cleared with time, resulting in corneas with optical clarity matching those of untreated controls. Biochemical analysis showed that by 12 months post operation, the initial RHCIII implants had been completely remodeled, as type I collagen, was the major collagenous protein detected, whereas no RHCIII could be detected. Histological analysis showed all implanted corneas exhibited regeneration of epithelial and stromal layers as well as nerves, along with touch sensitivity and tear production. Most neovascularization was seen in corneas stabilized by interrupted sutures. CONCLUSIONS This showed that the surgical technique used does have a significant effect on the overall performance of corneal implants, overlying sutures caused less vascularization than interrupted sutures. TRANSLATIONAL RELEVANCE Understanding the significance of the suturing technique can aid the selection of the most appropriate procedure when implanting artificial corneal substitutes. The same degree of regeneration, despite a higher collagen content indicates that future material development can progress toward stronger, more resistant implants.
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Fan Y, Oldenbeuving RM, Khan MRH, Roeloffzen CGH, Klein EJ, Lee CJ, Offerhaus HL, Boller KJ. Q-factor measurements through injection locking of a semiconductor-glass hybrid laser with unknown intracavity losses. OPTICS LETTERS 2014; 39:1748-1751. [PMID: 24686595 DOI: 10.1364/ol.39.001748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The injection locking properties of a newly developed waveguide-based external cavity semiconductor laser have been investigated. Using the injection locking properties to measure the Q-factor of complex optical cavities with unknown internal losses, has been demonstrated for the first time.
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You H, Kim GE, Na CH, Lee S, Lee CJ, Cho KH, Akiyama Y, Ishida T, No KT. An empirical model for gas phase acidity and basicity estimation. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2014; 25:91-115. [PMID: 24597990 DOI: 10.1080/1062936x.2013.864997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/09/2013] [Indexed: 06/03/2023]
Abstract
Gas phase acidity and basicity estimation models have been developed for acidic and basic functional groups of amino acid side-chains and also for a number of small organic molecules. The acidic functional groups include aliphatic and aromatic alcohol, and aliphatic and aromatic carboxylic acid, and the basic functional groups include aliphatic, aromatic and hetero-aromatic amines, and also pyridino-, pyrazolo- and imidazolo-groupings. The models are described in terms of a linear combination of descriptors that highly influence reactivity at the reaction centres of the functional groups. In order to describe the chemical environments of the deprotonating and protonating sites, atomic descriptors such as the effective atomic electronegativity and effective atomic polarizability of the atoms in the reaction field and the electrostatic potentials at the reaction sites have been introduced. The coefficient of determination (r(2)) of each model is above 0.8, apart from the imidazole model. The models are readily applicable, ranging from simple organic molecules to proteins.
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Lee CJ, Zhang Y, Takao H, Murayama Y, Qian Y. A fluid-structure interaction study using patient-specific ruptured and unruptured aneurysm: the effect of aneurysm morphology, hypertension and elasticity. J Biomech 2013; 46:2402-10. [PMID: 23962529 DOI: 10.1016/j.jbiomech.2013.07.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 07/17/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022]
Abstract
Fluid-structure interaction (FSI) simulations using five patient-specific aneurysm geometries are carried out to investigate the difference between ruptured and unruptured aneurysms. Two different blood pressure conditions (normal and hypertension, for all cases), and two different values of elastic modulus (1 and 2MPa, for two cases) are tested. Ruptured aneurysms (RA) generally displayed larger displacement at the dome, lower area-average WSS and higher von Mises stress than unruptured aneurysms (URA) regardless of elasticity or blood pressure condition. RAs had a longitudinal expansion whereas URAs had a radial expansion, which was the key difference between the two types. The difference in expansion pattern may be one of the keys to explaining aneurysm rupture, and further analysis is required in the future to confirm this theory.
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Oldenbeuving RM, Song H, Schitter G, Verhaegen M, Klein EJ, Lee CJ, Offerhaus HL, Boller KJ. High precision wavelength estimation method for integrated optics. OPTICS EXPRESS 2013; 21:17042-17052. [PMID: 23938552 DOI: 10.1364/oe.21.017042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel and simple approach to optical wavelength measurement is presented in this paper. The working principle is demonstrated using a tunable waveguide micro ring resonator and single photodiode. The initial calibration is done with a set of known wavelengths and resonator tunings. The combined spectral sensitivity function of the resonator and photodiode at each tuning voltage was modeled by a neural network. For determining the unknown wavelengths, the resonator was tuned with a set of heating voltages and the corresponding photodiode signals were collected. The unknown wavelength was estimated, based on the collected photodiode signals, the calibrated neural networks, and an optimization algorithm. The wavelength estimate method provides a high spectral precision of about 8 pm (5 · 10(-6) at 1550 nm) in the wavelength range between 1549 nm to 1553 nm. A higher precision of 5 pm (3 · 10(-6)) is achieved in the range between 1550.3 nm to 1550.8 nm, which is a factor of five improved compared to a simple lookup of data. The importance of our approach is that it strongly simplifies the optical system and enables optical integration. The approach is also of general importance, because it may be applicable to all wavelength monitoring devices which show an adjustable wavelength response.
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Lee CJ, Zhang Y, Takao H, Murayama Y, Qian Y. The influence of elastic upstream artery length on fluid-structure interaction modeling: a comparative study using patient-specific cerebral aneurysm. Med Eng Phys 2013; 35:1377-84. [PMID: 23664305 DOI: 10.1016/j.medengphy.2013.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 01/15/2013] [Accepted: 03/13/2013] [Indexed: 10/26/2022]
Abstract
Fluid-structure interaction (FSI) simulations using a patient-specific geometry are carried out to investigate the influence the length of elastic parent artery and the position of constraints in the solid domain on the accuracy of patient-specific FSI simulations. Three models are tested: Long, Moderate, and Short, based on the length of the elastic parent artery. All three models use same wall thickness (0.5 mm) and the elastic modulus (5 MPa). The maximum mesh displacement is the largest for the Long model (0.491 mm) compared to other models (0.3 mm for Moderate, and 0.132 mm for Short). The differences of hemodynamic and mechanical variables, aneurysm volume and cross-sectional area between three models are all found to be minor. In addition, the Short model takes the least amount of computing time of the three models (11h compared to 21 h for Long and 19 h for Moderate). The present results indicate that the use of short elastic upstream artery can shorten the time required for pati ent-specific FSI simulations without impacting the overall accuracy of the results.
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Hong HP, Jung KH, Kim JH, Kwon KH, Lee CJ, Yun KN, Min NK. Percolated pore networks of oxygen plasma-activated multi-walled carbon nanotubes for fast response, high sensitivity capacitive humidity sensors. NANOTECHNOLOGY 2013; 24:085501. [PMID: 23376938 DOI: 10.1088/0957-4484/24/8/085501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on the preparation of capacitive-type relative humidity sensors incorporating plasma-activated multi-wall carbon nanotube (p-MWCNT) electrodes and on their performance compared with existing commercial technology. Highly open porous conductive electrodes, which are almost impossible to obtain with conventional metal electrodes, are fabricated by spray-depositing MWCNT networks on a polyimide layer. Oxygen plasma activation of the MWCNTs is also explored to improve the water adsorption of the MWCNT films, by introducing oxygen-containing functional groups on the CNT surface. Polyimide humidity sensors with optimized p-MWCNT network electrodes exhibit exceptionally fast response times (1.5 for adsorption and 2 s for desorption) and high sensitivity (0.75 pF/% RH). These results may be partially due to their percolated pore structure being more accessible for water molecules, expending the diffusion of moisture to the polyimide sensing film, and partially due to the oxygenated surface of p-MWCNT films, allocating more locations for adsorption or attraction of water molecules to contribute to the sensitivity.
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Sun Z, Lee CJ, Mejia-Guerrero S, Zhang Y, Higuchi K, Li RK, Medin JA. Neonatal Transfer of Membrane-Bound Stem Cell Factor Improves Survival and Heart Function in Aged Mice After Myocardial Ischemia. Hum Gene Ther 2012; 23:1280-9. [DOI: 10.1089/hum.2012.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Yannarelli G, Dayan V, Pacienza N, Lee CJ, Medin J, Keating A. Human umbilical cord perivascular cells exhibit enhanced cardiomyocyte reprogramming and cardiac function after experimental acute myocardial infarction. Cell Transplant 2012; 22:1651-66. [PMID: 23043977 DOI: 10.3727/096368912x657675] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We were interested in evaluating the ability of the mesenchymal stromal cell (MSC) population, human umbilical cord perivascular cells (HUCPVCs), to undergo cardiomyocyte reprogramming in an established coculture system with rat embryonic cardiomyocytes. Results were compared with human bone marrow-derived (BM) MSCs. The transcription factors GATA4 and Mef 2c were expressed in HUCPVCs but not BM-MSCs at baseline and, at 7 days, increased 7.6- and 3.5-fold, respectively, compared with BM-MSCs. Although cardiac-specific gene expression increased in both cell types in coculture, upregulation was more significant in HUCPVCs, consistent with Mef 2c-GATA4 synergism. Using a lentivector with eGFP transcribed from the α-myosin heavy chain (α-MHC) promoter, we found that cardiac gene expression was greater in HUCPVCs than BM-MSCs after 14 days coculture (52±17% vs. 29±6%, respectively). A higher frequency of HUCPVCs expressed α-MHC protein compared with BM-MSCs (11.6±0.9% vs. 5.3±0.3%); however, both cell types retained MSC-associated determinants. We also assessed the ability of the MSC types to mediate cardiac regeneration in a NOD/SCID γ mouse model of acute myocardial infarction (AMI). Fourteen days after AMI, cardiac function was significantly better in cell-treated mice compared with control animals and HUCPVCs exhibited greater improvement. Although human cells persisted in the infarct area, the frequency of α-MHC expression was low. Our results indicate that HUCPVCs exhibit a greater degree of cardiomyocyte reprogramming but that differentiation for both cell types is partial. We conclude that HUCPVCs may be preferable to BM-MSCs in the cell therapy of AMI.
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Lee CJ, Eskandari MK. Imaging for carotid stenting. THE JOURNAL OF CARDIOVASCULAR SURGERY 2011; 52:795-801. [PMID: 22051988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Carotid artery stenting (CAS) using embolic protection devices (EPD) has emerged as a viable alternative to carotid endarterectomy (CEA) in select patients. Imaging plays a critical role in the selection of patients for CAS. Duplex ultrasonography alone is insufficient to assess patients for CAS suitability. Advancements in computed tomography angiography (CTA) and magnetic resonance angiography (MRA) techniques are helping to identify lesions vulnerable to cerebral embolization during carotid interventions - a more prevalent event during CAS in comparison to CEA. Here we review the relevant data on the various imaging techniques available to improve patient selection and minimize neurologic adverse events during carotid artery stenting.
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Sim WS, Choi JW, Lee CJ, Nahm FS, Lee SH, Shin BS, Cho HS. The influence of patient position on withdrawal force of thoracic epidural catheters. Anaesthesia 2011; 67:19-22. [PMID: 21972884 DOI: 10.1111/j.1365-2044.2011.06913.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the forces required to remove thoracic epidural catheters to determine the effect of patient position on removal. Eighty-four patients undergoing open thoracotomy and thoracic patient-controlled epidural analgesia were enrolled. Catheterisation was performed under fluoroscopic guidance before surgery, and the patients were allocated to one of three position groups for removal: prone; sitting; and lateral. On the third postoperative day, the peak tension during withdrawal in the assigned position was measured. No differences in mean (SD) forces were found between groups: prone 1.61 (0.39) N, supine 1.62 (0.61) N and lateral 1.36 (0.56) N (p = 0.140). The withdrawal forces required to remove thoracic epidural catheters were not affected by the position. Thus, the position for removal can be determined by patient's choice and clinical judgement.
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Kim WH, Lee CJ, Sim WS, Shin BS, Ahn HJ, Lim HY. Anatomical Analysis of Computed Tomography Images for Determining the Optimal Oblique Fluoroscope Angle for Percutaneous Coeliac Plexus Block. J Int Med Res 2011; 39:1798-807. [DOI: 10.1177/147323001103900522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This retrospective study used abdominal computed tomography (CT) scan images to determine the optimal safe oblique angle for fluoroscopy in fluoroscope-assisted coeliac plexus block (CPB). Abdominal CT scans from 131 patients were included in the study: 42 patients with cancer of the pancreas head, 45 with cancer of the pancreas body and tail and 44 with chronic pancreatitis. The oblique angle and entry distance from the midline were measured at the T12 and L1 levels, and the safe angle range that avoided puncture of the organs was also measured. The optimal angle varied between the T12 and L1 levels, and between the right and left sides at the T12 level. There was no difference in the oblique angle between the patient groups. The optimal oblique angle for fluoroscopy was determined to be 17° for right T12, 18° for left T12, and 19° for both left and right L1.
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