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Choi, B.

Publications and source records attributed to Choi, B..

2 recordsLinked to original sources

Impact of Chronic Total Occlusion Lesion Length onSix-month Angiographic and 2-year Clinical Outcomes

BackgroundSuccessful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is known to be associated with improved clinical outcomes compared with failed CTO PCI. However, it is not clear whether the angiographic and clinical outcomes of long CTO lesionis different with those of short CTO lesion in the drug eluting stent (DES) era.\n\nMethod sand ResultsA total of 235 consecutive patients underwent successful CTO intervention were divided into two groups according the CTO lesion length. Six-month angiographic and two-year clinical outcomes were compared between the two groups. The baseline clinical characteristics were similar between the two groups except prior PCI was more frequent in long CTO group whereas bifurcation lesion was more frequent in the short CTO group. In-hospital complications were similar between the two groups except intimal dissection was more frequent in long CTO group. Both groups had similar angiographic outcomes at 6 months and clinical outcomes up to 2 years except the incidence of repeat PCI, predominantly target vessel revascularization (TVR) was higher in long CTO group. In multivariate analysis, long CTO was an important predictor for repeat PCI (OR;4.26, CI 1.53-11.9, p=0.006).\n\nConclusionThe safety profile, angiographic and 2-year clinical outcomes were similar between the two groups except higher incidence of repeat PCI in long CTO group despite of successful PCI with DESs.

physiology

Beyond the Michaelis-Menten equation: Accurate and efficient estimation of enzyme kinetic parameters

Examining enzyme kinetics is critical for understanding cellular systems and for using enzymes in industry. The Michaelis-Menten equation has been widely used for over a century to estimate the enzyme kinetic parameters from reaction progress curves of substrates, which is known as the progress curve assay. However, this canonical approach works in limited conditions, such as when there is a large excess of substrate over enzyme. Even when this condition is satisfied, the identifiability of parameters is not always guaranteed, and often not verifiable in practice. To overcome such limitations of the canonical approach for the progress curve assay, here we propose a Bayesian approach based on an equation derived with the total quasi-steady-state approximation. In contrast to the canonical approach, estimates obtained with this proposed approach exhibit little bias for any combination of enzyme and substrate concentrations. Importantly, unlike the canonical approach, an optimal experiment to identify parameters with certainty can be easily designed without any prior information. Indeed, with this proposed design, the kinetic parameters of diverse enzymes with disparate catalytic efficiencies, such as chymotrypsin, fumarase, and urease, can be accurately and precisely estimated from a minimal amount of timecourse data. A publicly accessible computational package performing the Bayesian inference for such accurate and efficient enzyme kinetics is provided.

systems biology