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Chen TC, Lin MJ, Chen HL, Nosaka K. Threshold Number Of Low-intensity Eccentric Contractions Of The Elbow Flexors To Induce Muscle Damage. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000519583.37259.0a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tseng KW, Tseng WC, Lin MJ, Chen HL, Nosaka K, Chen TC. Protective effect by maximal isometric contractions against maximal eccentric exercise-induced muscle damage of the knee extensors. Res Sports Med 2016; 24:243-56. [DOI: 10.1080/15438627.2016.1202826] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chen TC, Lin MR, Ho CC, Chen HL, Tseng KW, Nosaka K. Proprioception Changes After Eccentric Exercise Of The Elbow Flexors. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000485550.47876.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Damas F, Nosaka K, Libardi CA, Chen TC, Ugrinowitsch C. Susceptibility to Exercise-Induced Muscle Damage: a Cluster Analysis with a Large Sample. Int J Sports Med 2016; 37:633-40. [PMID: 27116346 DOI: 10.1055/s-0042-100281] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We investigated the responses of indirect markers of exercise-induced muscle damage (EIMD) among a large number of young men (N=286) stratified in clusters based on the largest decrease in maximal voluntary contraction torque (MVC) after an unaccustomed maximal eccentric exercise bout of the elbow flexors. Changes in MVC, muscle soreness (SOR), creatine kinase (CK) activity, range of motion (ROM) and upper-arm circumference (CIR) before and for several days after exercise were compared between 3 clusters established based on MVC decrease (low, moderate, and high responders; LR, MR and HR). Participants were allocated to LR (n=61), MR (n=152) and HR (n=73) clusters, which depicted significantly different cluster centers of 82%, 61% and 42% of baseline MVC, respectively. Once stratified by MVC decrease, all muscle damage markers were significantly different between clusters following the same pattern: small changes for LR, larger changes for MR, and the largest changes for HR. Stratification of individuals based on the magnitude of MVC decrease post-exercise greatly increases the precision in estimating changes in EIMD by proxy markers such as SOR, CK activity, ROM and CIR. This indicates that the most commonly used markers are valid and MVC orchestrates their responses, consolidating the role of MVC as the best EIMD indirect marker.
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Wan KS, Wu WF, Chen TC, Wu CS, Hung CW, Chang YS. Comparison of amoxicillin + clavulanate with or without intranasal fluticasone for the treatment of uncomplicated acute rhinosinusitis in children. Minerva Pediatr 2015; 67:489-494. [PMID: 26530491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
AIM Intranasal corticosteroids (INS) have been proven effective in controlling postnasal drip, decreasing inflammatory response, reducing nasal swelling, and increasing aeration of the sinuses such that INS are recommended as treatment of sinusitis. METHODS Fifty children with acute rhinosinusitis, 50 children with acute rhiniosinusitis and allergic rhinitis (AR), and 20 rhiniosinusitis children as control were selected for investigation. Each group had a single-blind treatment of three types: with coamoxiclav only, with coamoxiclav plus INS, and with matched placebo (without antibiotics and INS) for two weeks. Nasal symptoms were then evaluated. The outcome was measured by using major symptom score (MSS) after treatment for 14 days. RESULTS Therapeutic effectiveness was 92% in rhinosinusitis patients treated with co-amoxiclav and 84% in those treated with co-amoxiclav plus INS. Among patients with sinusitis combined with AR, therapeutic efficacy was 88% for those treated with co-amoxiclav and 96% for those treated with co-amoxiclav plus INS. Only 30% of the symptoms were reduced in the placebo group. CONCLUSION There are no statistical differences in the acute sinusitis group treated with co-amoxiclav with or without INS. In the sinusitis with AR group, the efficacy of co-amoxiclav with INS is higher than in children treated with co-amoxiclav alone.
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Chen TC, Chen HL, Lin MR, Nosaka K. Proprioception After a Repeated Bout of Eccentric Exercise of the Contralateral Elbow Flexors. Med Sci Sports Exerc 2015. [DOI: 10.1249/01.mss.0000477831.96471.81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hsieh CC, Chen TC, Tseng KW, Chen JL. The Effect Of Stair Exercise On Insulin Sensitivity In Elderly Females. Med Sci Sports Exerc 2015. [DOI: 10.1249/01.mss.0000477106.75145.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wu H, de Boer JF, Chen L, Chen TC. Correlation of localized glaucomatous visual field defects and spectral domain optical coherence tomography retinal nerve fiber layer thinning using a modified structure-function map for OCT. Eye (Lond) 2015; 29:525-33. [PMID: 25633881 DOI: 10.1038/eye.2014.317] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/30/2014] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To study the correlation between glaucomatous visual field (VF) defects assessed by standard automated perimetry (SAP) and peripapillary retinal nerve fiber layer (RNFL) thinning measured by spectral domain optical coherence tomography (OCT) using a modified OCT-based peripapillary RNFL structure-function map. PATIENTS AND METHODS Perimetric glaucoma patients and age-matched normal control subjects were recruited from a university hospital clinic. All eyes underwent testing with the Spectralis spectral domain OCT and SAP on the same day. An OCT-based correspondence map, which correlated VF areas with peripapillary RNFL sectors was created to evaluate the relationship between glaucomatous RNFL thinning and VF loss in six nerve fiber layer bundle areas. Correlations of RNFL thinning with corresponding VF defects were examined using Spearman rank-order correlations. To demonstrate the association between localized VF defects and RNFL thickness, the theoretical curves were made according to an established log-linear model. The measured RNFL thickness values and VF defects were presented in the same scatterplot for each sector. RESULTS Fifty-six glaucoma patients and 85 normal subjects were included in the study. Significant association between localized VF loss and RNFL thinning was found in corresponding areas. Data from the current study fit well with established log-linear models, which compare RNFL thickness values with VF defects. CONCLUSION Analysis of RNFL thinning in eyes with localized glaucomatous VF defects showed good structure-function correlation in a new OCT-based structure-function correspondence map.
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Chen CS, Lai YT, Chen TC, Chen CH, Lee JF, Hsu CW, Kao HM. Synthesis and characterization of Pt nanoparticles with different morphologies in mesoporous silica SBA-15 for methanol oxidation reaction. NANOSCALE 2014; 6:12644-12654. [PMID: 25198619 DOI: 10.1039/c4nr03624g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Mesoporous SBA-15 silica materials functionalized with and without carboxylic acid groups were used to effectively control the morphology of Pt crystals, and the materials thus obtained were applied to methanol oxidation reactions. The Pt particles aggregated to form long spheroids inside the channels in pure SBA-15. When carboxylic acid groups were utilized, the SBA-15(-COOH) material facilitated the formation of higher Pt surface area, smaller Pt nanoparticles and nearly spherical shape due to the strong interaction between Pt(4+) ions and carboxylic acid on SBA-15. The Pt(4+) ions on the SBA-15(-COOH) material can be directly transformed to reduced Pt particles during calcination. The methanol oxidation activity on a Pt surface is strongly dependent on the shape of Pt particles. The near-spherical Pt nanoparticles on the SBA-15(-COOH) exhibited higher catalytic activity during methanol oxidation than Pt catalysts on unmodified SBA-15. The near-spherical Pt particles on the SBA-15(-COOH) contained large numbers of terrace sites on their surfaces, which led to high efficiency during methanol oxidation.
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Lang HC, Chen TC, Chen CH. The Cost Comparison Of Drug-Eluting Stents (Des) And Bare-Metal Stents (Bms) - A Retrospective Cohort Matched Study. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2014; 17:A481. [PMID: 27201407 DOI: 10.1016/j.jval.2014.08.1396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Lee KH, Lee YT, Chen TC, Yeh CC, Chen JY, Liu LY, Chi CH. Effects of sheng hua tang on uterine involution and ovarian activity in postpartum dairy cows. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2014; 26:1247-54. [PMID: 25049906 PMCID: PMC4093405 DOI: 10.5713/ajas.2013.13042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 05/16/2013] [Accepted: 04/08/2013] [Indexed: 11/27/2022]
Abstract
The effects of Sheng Hua Tang (SHT) on uterine involution and ovarian activity were investigated in postpartum dairy cows. SHT (70 g) was given to dairy cows (n = 10) to evaluate its effects for five days from the first postpartum day. Postpartum cows fed with a basal diet without SHT were used as the control group (n = 10). Ultrasounds and blood tests were recorded for four weeks from postpartum day seven with a 3-d interval. The results showed that the areas and diameters of endometria were significantly (p<0.01) reduced in the group that received SHT compared to the control group on the seventh postpartum day. The group that received SHT had an intrauterine fluid volume mean of 1.2±0.6 cm(3), which was significantly lower than that of the control group, 2.3±0.8 cm(3) (p<0.01) on the 13th postpartum day. In addition, the uterine tension score was a mean of 1.0±0.0 in the group that received SHT, which was also significantly lower than that of the control group, 1.5±0.5 (p<0.01) on the 19th postpartum day. Taken together, the Chinese herbal medicine remedy, SHT, promoted uterine involution and ovarian activity in postpartum dairy cows.
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Chen TC, Chen HL, Lin MJ, Chen KC, Wu BH, Nosaka K. Low-intensity Eccentric Contractions Attenuate Maximal Eccentric Contraction-induced Muscle Damage of the Knee Extensors. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000496278.51160.d7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Chen TC, Chen HL, Liu YC, Nosaka K. Eccentric exercise-induced muscle damage of pre-adolescent and adolescent boys in comparison to young men. Eur J Appl Physiol 2014; 114:1183-95. [DOI: 10.1007/s00421-014-2848-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 02/06/2014] [Indexed: 10/25/2022]
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Chen TC, Chang SW, Wang TY. Moxifloxacin modifies corneal fibroblast-to-myofibroblast differentiation. Br J Pharmacol 2013; 168:1341-54. [PMID: 23072440 DOI: 10.1111/bph.12015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Revised: 09/24/2012] [Accepted: 09/28/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Fibroblast-to-myofibroblast differentiation is associated with scarring, an important issue in corneal surgery. Moxifloxacin (MOX), commonly applied to prevent post-operative infection, would benefit more if it modifies fibroblast-to-myofibroblast differentiation other than antimicrobial activity. Our purpose was to explore whether MOX has anti-fibrotic effect in human corneal fibroblasts (HCFs). EXPERIMENTAL APPROACH HCFs were incubated in MOX-containing medium concurrently with TGF-β1 (co-treatment), before (pretreatment) or after (post-treatment) adding TGF-β1. HCF contractility was evaluated with a type I collagen gel contraction assay. Expression of α-smooth muscle actin (α-SMA), Smad2, phospho-Smad2-Ser467, Smad4 and Smad7 was determined by immunoblotting. Formation of α-SMA-positive filaments and distribution of active Smad2 were observed under confocal microscopy. Expression of TGF-β receptor types I (TGFBR1) and II (TGFBR2) was assessed with flow cytometry. KEY RESULTS MOX did not affect gel contractility or α-SMA filament formation in HCFs without TGF-β1 stimulation. MOX did, however, retard HCF-containing gel contractility and α-SMA filament formation following TGF-β1 stimulation in the pretreatment and co-treatment groups but not in the post-treatment group. MOX blocked the expression of Smad2, phospho-Smad2-Ser467 and TGFBR1 under TGF-β1 incubation. Additionally, MOX enhanced Smad7 expression in TGF-β1-incubated HCFs, but did not interfere with TGF-β-triggered Smad2 nuclear translocation or Smad4 expression. CONCLUSIONS AND IMPLICATIONS MOX inhibited TGF-β-induced fibroblast-to-myofibroblast differentiation via blocking TGFBR1 and enhancing Smad7 expression. MOX should be used before or during surgery to achieve these effects. These results suggest a de novo mechanism by which MOX participates in corneal wound healing.
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Lin SY, Lee KM, Chen TC, Lien CT, Lu PL. A swollen knee in a 77-year-old lung cancer patient receiving antimicrobial therapy for pneumonia. Clin Infect Dis 2013; 56:1778, 1838-9. [PMID: 23690369 DOI: 10.1093/cid/cit131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Chen TC, Tseng WC, Huang GL, Chen HL, Tseng KW, Nosaka K. Low-intensity eccentric contractions attenuate muscle damage induced by subsequent maximal eccentric exercise of the knee extensors in the elderly. Eur J Appl Physiol 2012; 113:1005-15. [DOI: 10.1007/s00421-012-2517-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/27/2012] [Indexed: 10/27/2022]
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Chen HL, Nosaka K, Pearce AJ, Chen TC. Two maximal isometric contractions attenuate the magnitude of eccentric exercise-induced muscle damage. Appl Physiol Nutr Metab 2012; 37:680-9. [DOI: 10.1139/h2012-035] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated whether maximal voluntary isometric contractions (MVC-ISO) would attenuate the magnitude of eccentric exercise-induced muscle damage. Young untrained men were placed into one of the two experimental groups or one control group (n = 13 per group). Subjects in the experimental groups performed either two or 10 MVC-ISO of the elbow flexors at a long muscle length (20° flexion) 2 days prior to 30 maximal isokinetic eccentric contractions of the elbow flexors. Subjects in the control group performed the eccentric contractions without MVC-ISO. No significant changes in maximal voluntary concentric contraction peak torque, peak torque angle, range of motion, upper arm circumference, plasma creatine kinase (CK) activity and myoglobin concentration, muscle soreness, and ultrasound echo intensity were evident after MVC-ISO. Changes in the variables following eccentric contractions were smaller (P < 0.05) for the 2 MVC-ISO group (e.g., peak torque loss at 5 days after exercise, 23% ± 3%; peak CK activity, 1964 ± 452 IU·L–1; peak muscle soreness, 46 ± 4 mm) or the 10 MVC-ISO group (13% ± 3%, 877 ± 198 IU·L–1, 30 ± 4 mm) compared with the control (34% ± 4%, 6192 ± 1747 IU·L–1, 66 ± 5 mm). The 10 MVC-ISO group showed smaller (P < 0.05) changes in all variables following eccentric contractions compared with the 2 MVC-ISO group. Therefore, two MVC-ISO conferred potent protective effects against muscle damage, whereas greater protective effect was induced by 10 MVC-ISO, which can be used as a strategy to minimize muscle damage.
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Jiwani AZ, Rhee DJ, Brauner SC, Gardiner MF, Chen TC, Shen LQ, Chen SH, Grosskreutz CL, Chang KK, Kloek CE, Greenstein SH, Borboli-Gerogiannis S, Pasquale DL, Chaudhry S, Loomis S, Wiggs JL, Pasquale LR, Turalba AV. Effects of caffeinated coffee consumption on intraocular pressure, ocular perfusion pressure, and ocular pulse amplitude: a randomized controlled trial. Eye (Lond) 2012; 26:1122-30. [PMID: 22678051 DOI: 10.1038/eye.2012.113] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To examine the effects of caffeinated coffee consumption on intraocular pressure (IOP), ocular perfusion pressure (OPP), and ocular pulse amplitude (OPA) in those with or at risk for primary open-angle glaucoma (POAG). METHODS We conducted a prospective, double-masked, crossover, randomized controlled trial with 106 subjects: 22 with high tension POAG, 18 with normal tension POAG, 20 with ocular hypertension, 21 POAG suspects, and 25 healthy participants. Subjects ingested either 237 ml of caffeinated (182 mg caffeine) or decaffeinated (4 mg caffeine) coffee for the first visit and the alternate beverage for the second visit. Blood pressure (BP) and pascal dynamic contour tonometer measurements of IOP, OPA, and heart rate were measured before and at 60 and 90 min after coffee ingestion per visit. OPP was calculated from BP and IOP measurements. Results were analysed using paired t-tests. Multivariable models assessed determinants of IOP, OPP, and OPA changes. RESULTS There were no significant differences in baseline IOP, OPP, and OPA between the caffeinated and decaffeinated visits. After caffeinated as compared with decaffeinated coffee ingestion, mean mm Hg changes (± SD) in IOP, OPP, and OPA were as follows: 0.99 (± 1.52, P<0.0001), 1.57 (± 6.40, P=0.0129), and 0.23 (± 0.52, P<0.0001) at 60 min, respectively; and 1.06 (± 1.67, P<0.0001), 1.26 (± 6.23, P=0.0398), and 0.18 (± 0.52, P=0.0006) at 90 min, respectively. Regression analyses revealed sporadic and inconsistent associations with IOP, OPP, and OPA changes. CONCLUSION Consuming one cup of caffeinated coffee (182 mg caffeine) statistically increases, but likely does not clinically impact, IOP and OPP in those with or at risk for POAG.
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Farraye FA, Nimitphong H, Stucchi A, Dendrinos K, Boulanger AB, Vijjeswarapu A, Tanennbaum A, Biancuzzo R, Chen TC, Holick MF. Use of a novel vitamin D bioavailability test demonstrates that vitamin D absorption is decreased in patients with quiescent Crohn's disease. Inflamm Bowel Dis 2011; 17:2116-21. [PMID: 21910173 DOI: 10.1002/ibd.21595] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 11/03/2010] [Indexed: 12/13/2022]
Abstract
BACKGROUND Vitamin D deficiency is a common problem in patients with Crohn's disease (CD). The aim of this study was to determine the ability of normal subjects and patients with quiescent CD to absorb vitamin D(2) using a novel vitamin D bioavailability test. In addition, we evaluated whether the location of disease or previous surgery had any influence on the bioavailability of vitamin D(2) in CD patients. METHODS Ten normal subjects (50% female) and 37 CD patients with quiescent disease (51% female) were included in this study. Subjects who recently received any vitamin D(2) were excluded. The vitamin D bioavailability test was performed in all subjects. After a baseline blood draw, all subjects were then given a single 50,000 IU oral dose of vitamin D(2) in a capsule formulation and had their blood drawn 12 hours later to determine serum vitamin D(2), which reflected their vitamin D(2) absorption capacity. RESULTS Forty-two percent and 29% of CD patients were found to be either vitamin D-deficient (25-hydroxyvitamin D [25(OH)D] ≤20 ng/mL] or insufficient [25(OH)D 21-29 ng/mL], respectively. Twelve hours after ingesting 50,000 IU vitamin D(2) , vitamin D(2) levels rose from a baseline of 0.7 ± 0.7 ng/mL (mean ± SEM) to 49.8 ± 3.0 ng/mL in normal subjects. In CD patients, baseline vitamin D(2) levels rose from 0 ng/mL to 34.8 ± 2.8 ng/mL. CD patients had on average a 30% decrease in their ability to absorb vitamin D(2) (P = 0.01). Moreover, we found a wide variability of vitamin D(2) bioavailability in CD patients. Analysis of variance (ANOVA) revealed no statistical difference of vitamin D(2) bioavailability between patients in the CD subgroup stratified by the location of disease, the type of surgery, and receiving or not receiving surgery. CONCLUSIONS More than 70% of the patients with quiescent CD were vitamin D-deficient or insufficient. The ability to absorb vitamin D(2) in CD patients is unpredictable and the only way to determine this is to perform a vitamin D bioavailability test. Use of this test may guide clinicians in administering the appropriate therapeutic dose of vitamin D for treating vitamin D deficiency in patients with CD.
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Chen CH, Nosaka K, Chen HL, Lin MJ, Tseng KW, Chen TC. Effects of flexibility training on eccentric exercise-induced muscle damage. Med Sci Sports Exerc 2011; 43:491-500. [PMID: 20689450 DOI: 10.1249/mss.0b013e3181f315ad] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study investigated whether flexibility training would attenuate muscle damage induced by maximal eccentric exercise. METHODS Thirty untrained young men were allocated to static stretching (SS), proprioceptive neuromuscular facilitation (PNF), or control group (n = 10 per group). The SS consisted of 30 sets of a 30-s standard SS with a 30-s rest between sets, and the PNF included 5 sets of the 30-s standard SS followed by 3 sets of three "contract-relax-agonist-contract" procedures. These were performed three times a week for 8 wk, and all subjects performed six sets of 10 maximal isokinetic (30°·s) lengthening contractions of the knee flexors after the 8-wk training or 8 wk after the baseline measures (control). Changes in indirect markers of muscle damage before and for 5 d after the eccentric exercise were compared among the groups. RESULTS The range of motion (ROM) of the hip joint increased by 25°, and the optimum angle of the knee flexors shifted (P < 0.05) to a longer muscle length by 10° after training, without significant differences between SS and PNF. No significant changes in these variables were evident for the control group. Compared with the control group, the SS and PNF groups showed significantly (P < 0.05) smaller decreases and faster recovery of knee flexor muscle strength and smaller changes in optimum angle, ROM, muscle soreness, and plasma creatine kinase activity and myoglobin concentration without significant differences between the groups. The preeccentric exercise ROM or optimum angle was significantly (P < 0.05) correlated with the changes in the muscle damage markers. CONCLUSIONS These results suggest that both SS and PNF training are effective in attenuating eccentric exercise-induced muscle damage and that flexible muscles are less susceptible to the damage.
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Chen HL, Nosaka K, Chen TC. Muscle damage protection by low-intensity eccentric contractions remains for 2 weeks but not 3 weeks. Eur J Appl Physiol 2011; 112:555-65. [DOI: 10.1007/s00421-011-1999-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 05/02/2011] [Indexed: 11/28/2022]
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Lin MJ, Chen HL, Tseng WC, Huang GL, Ko SC, Wu CJ, Lin JH, Lin JC, Chen TC. Comparison in Eccentric Exercise-Induced Muscle Damage on Rate of Velocity Development among Four Limb Muscles. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000401015.86565.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tseng WC, Chen HL, Huang GL, Wu CJ, Lin JH, Ko SC, Chen TC. Rate Of Velocity Development Less Decreased Following The Repeated Bout Of Maximal Eccentric Exercise. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000401021.73104.be] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lin MJ, Chen HL, Wu CJ, Tseng WC, Ko SC, Lin JC, Chen TC. Effects Of Gradient Variations On Physiological Responses To A 30-minute Run. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000384696.83104.82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ghosh A, Joo NE, Chen TC, Kapila YL. Proapoptotic fibronectin fragment induces the degradation of ubiquitinated p53 via proteasomes in periodontal ligament cells. J Periodontal Res 2010; 45:481-7. [PMID: 20337881 DOI: 10.1111/j.1600-0765.2009.01261.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVE The extracellular matrix (ECM) plays a key role in signaling necessary for tissue remodeling and cell survival. However, signals from the ECM altered by disease, e.g. inflammatory diseases such as periodontitis and arthritis, may lead to apoptosis or programmed cell death of resident cells. Previously, we found that a disease-associated fibronectin fragment triggers apoptosis of primary human periodontal ligament cells via a novel apoptotic pathway in which the tumor suppressor, p53, is transcriptionally downregulated. MATERIAL AND METHODS We used immunofluorescence, transfection assays, western blotting and ELISAs to show that p53 is degraded by a proteasomal pathway in response to a proapoptotic disease-associated fibronectin fragment. RESULTS We found that in these apoptotic conditions, p53 is further downregulated by post-translational ubiquitination and subsequent targeting to proteasomes for degradation. Pretreatment of cells with the proteasomal inhibitors MG132 and lactacystin rescued the cells from apoptosis. The p53 levels in cells transfected with ubiquitin small interfering RNA were resistant to degradation induced by the proapoptotic fibronectin fragment, showing that ubiquitination is important for the proapoptotic fibronectin fragment-induced degradation of p53. CONCLUSION These data show that a proapoptotic fibronectin matrix induces ubiquitination and degradation of p53 in the proteasome as part of a novel mechanism of apoptosis associated with inflammatory diseases.
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