36 research outputs found

    Paraoxonase-1 Is Not a Major Determinant of Stent Thrombosis in a Taiwanese Population

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    BACKGROUND: Clopidogrel is a prodrug that undergoes in vivo bioactivation to show its antiplatelet effects. Recent studies have shown that cytochrome P450 (CYP), ATP-binding cassette transporters (ABCB1), and paraoxonase-1 (PON1) play crucial roles in clopidogrel bioactivation. Here, we aim to determine the effects of genetic polymorphisms of CYP (CYP 2C19*2, CYP 2C19*3, and CYP 2C19*17), ABCB1 (ABCB1 3435C>T, ABCB1 129T>C, and ABCB1 2677G>T/A), and PON1 (PON1 Q192R, PON1 L55M, and PON1 108C>T) on the development of stent thrombosis (ST) in patients receiving clopidogrel after percutaneous coronary intervention (PCI). METHODS AND RESULTS: We evaluated the incidence of ST (0.64%) in 4964 patients who were recruited in the CAPTAIN registry (Cardiovascular Atherosclerosis and Percutaneous TrAnsluminal INterventions). The presence of genetic polymorphisms was assessed in 20 subjects who developed ST after aspirin and clopidogrel therapy and in 40 age- and sex-matched control subjects who did not develop ST, which was documented after 9 months of angiographic follow-up. ST was acute in 5 subjects, subacute in 7, late in 7, and very late in 1. The presence of CYP 2C19*2 allele was significantly associated with ST (adjusted odds ratio [ORadj]: 4.20, 95% confidence interval [CI], 1.263-9.544; P = 0.031). However, genetic variations in PON1 and ABCB1 showed no significant association with ST. CONCLUSION: We conclude that in a Taiwanese population, PON1 Q192R genotype is not associated with ST development after PCI. However, the presence of CYP 2C19*2 allele is a risk factor for ST development after PCI

    Blockchain Technology Adoption Behavior and Sustainability of the Business in Tourism and Hospitality SMEs: An Empirical Study

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    This paper investigates the factors influencing the intention to adopt cryptocurrency payments among small to medium-sized enterprises (SMEs) in tourism and hospitality through the lens of the technology acceptance model (TAM). This paper uses an original sample of 101 SMEs employing a total of 15,831 people in Taiwan. Structural equation modeling is used to examine the joint effect of both internal and external factors influencing the intention to use cryptocurrency payments. Results show that (1) strategic orientation, owner/managers personal characteristics (self-efficacy and innovativeness) and social influence have a strong effect on the intention to adopt new technology; (2) perceived usefulness mediates the effects of strategic orientation and social influence; and (3) perceived ease of use mediates the effect of self-efficacy on the intention to adopt cryptocurrency payments. The present study is one of few empirical inquiries about cryptocurrency payment adoption among SMEs. This study extends the theoretical foundations of the TAM into the specific characteristics of SMEs. Limitations of the study are sample size and a single survey design. However, findings of this research on the cryptocurrency payment adoption offer practical implications for tourism stakeholders towards supporting SMEs competitiveness. The originality of this study is based on the fact that cryptocurrency payment is a new technology, and on the potential of cryptocurrency payments to disrupt the traditional way of operating tourism and hospitality SMEs. Hence the importance to consider major factors influencing SMEs’ intentions to adopt this technology

    One KHz Order Narrow Linewidth Fiber Laser Using Rayleigh Backscattering Mechanism in an Additional Piece Optical Fiber

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    A simple, low-cost, single-longitudinal mode, C-band narrow-linewidth optical fiber laser is presented based on the methodology of the Rayleigh backscattering (RBS). In this paper, a 1551 nm fiber ring laser is developed, and single-mode fiber (SMF) is added to compress the line width. When the SMF length of the RBS cavity is 120 m, the laser has better performance than that in other SMF lengths with a laser line width of 1.46 KHz with housing shield. The optical signal-to-noise ratio (OSNR) is 59.86 dB, and its maximum output power is 9.4 mW. It can quickly achieve the single longitude-mode operation by controlling the variable optical attenuator (VOA). The bit error rate at 10 Gb/s PRBS NRZ modulation is measured to be 10−9 when the optical receiving power is −16.2 dBm

    Alteration of gap junctions and connexins in the right atrial appendage during cardiopulmonary bypass

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    AbstractObjectives: We investigated the influence of cardiopulmonary bypass on cardiomyocyte gap junctions and connexins. Methods: Samples were collected at intervals during operation from the right atrial appendage in 21 patients (mean [± SD] age 55 ± 21 years). Immunodetection of connexins was conducted by Western blotting and confocal microscopy with parallel electron microscopic examination of gap junctions. Results: Downregulation of connexin 43 during the course of operation occurred in more than half of the patients. The mean densitometric value of connexin 43 decreased by 23%, with samples from patients with coronary artery disease showing a greater reduction than seen in those from patients with other diseases (31% ± 22% vs 10% ± 24%, P =.04). Such alterations were confirmed by confocal microscopy, which also demonstrated reduced connexin 45 immunolabeling in most patients. Electron microscopy revealed a reduction in the dimensions of cell membrane-located gap junctions and more frequent intracytoplasmic gap junctional membrane in samples from later time points (P =.04). Conclusions: Downregulation of connexins accompanied by a reduction in gap junctions is common in the cardiomyocytes of the right atrial appendage during cardiopulmonary bypass. The association of a marked reduction in connexin 43 with coronary artery disease may imply inadequate intraoperative cardiac protection in patients with this disease.J Thorac Cardiovasc Surg 2002;124:1106-1

    Left atrial emptying fraction predicts recurrence of atrial fibrillation after radiofrequency catheter ablation

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    <div><p>Background</p><p>Compared with left atrial (LA) dimension, LA emptying fraction (LAEF) has received less emphasis as a predictor of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA). In addition, patients experiencing post-RFCA AF recurrence may respond to previously ineffective antiarrhythmic drugs (AADs). Classifying these patients into a third RFCA outcome category is recommended.</p><p>Objective</p><p>To identify predictors of RFCA outcome classified into three categories, and to build proportional odds logistic regression models for clinical applicability to predict AF recurrence.</p><p>Methods</p><p>Data were retrospectively collected from 483 consecutive patients with drug-refractory AF undergoing RFCA (328 men; age 58.4 ± 11.5 years; 383 paroxysmal). Patients were classified into 3 groups based on the last RFCA outcome: group 1, free from AF without AADs; group 2, free from AF with AADs; and group 3, recurrence of AADs-refractory atrial tachyarrhythmia.</p><p>Results</p><p>After a mean follow-up duration of 64.5 ± 43.2 months and mean ablation procedure number of 1.37 ± 0.68, the RFCA outcome showed 76.0%, 9.5% and 14.5% of patients in groups 1, 2, and 3, respectively. In multivariate analysis, LAEF was the most stable and important predictor of AF recurrence, followed by body mass index, stroke, AF duration, mitral regurgitation, and LA linear ablation. For patients undergoing repeat RFCA, LAEF was the only independent predictor (cutoffs: 43% and 35% for groups 1 and 3, respectively).</p><p>Conclusion</p><p>LAEF provides optimal prognostic information regarding the risk stratification of AF patients undergoing RFCA.</p></div
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