Background: Heterogeneity in plaque composition in human coronary artery bifurcations is associated with blood flow induced shear stress. Shear stress is generally determined by combing 3D lumen data and computational fluid dynamics (CFD). We investigated two new procedures to generate 3D lumen reconstructions of coronary artery bifurcations for shear stress computations.
Methods: We imaged 10 patients with multislice computer tomography (MSCT) and intravascular ultrasound (IVUS). The 3D reconstruction of the main branch was based on the fusion of MSCT and IVUS. The proximal part of side branch was reconstructed using IVUS data or MSCT data, resulting in two different reconstructions of the bifurcation region. The distal part of the side branch was based on MSCT data alone. The reconstructed lumen was combined with CFD to determine the shear stress. Low and high shear stress regions were defined and shear stress patterns in the bifurcation regions were investigated.
Results: The 3D coronary bifurcations were successfully generated with both reconstruction procedures. The geometrical features of the bifurcation region for the two reconstruction procedures did not reveal appreciable differences. The shear stress maps showed a qualitative agreement, and the low and high shear stress regions were similar in size and average shear stress values were identical. The low and high shear stress regions showed an overlap of approximately 75%.
Conclusion: Reconstruction of the side branch with MSCT data alone is an adequate technique to study shear stress and wall thickness in the bifurcation region. The reconstruction procedure can be applied to further investigate the effect of shear stress on atherosclerosis in coronary bifurcations.
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http://dx.doi.org/10.1016/j.jbiomech.2013.10.021 | DOI Listing |
Sci Adv
January 2025
Yale Cardiovascular Research Center, Yale School of Medicine, New Haven, CT 06511, USA.
Fluid shear stress (FSS) from blood flow sensed by vascular endothelial cells (ECs) determines vessel behavior, but regulatory mechanisms are only partially understood. We used cell state transition assessment and regulation (cSTAR), a powerful computational method, to elucidate EC transcriptomic states under low shear stress (LSS), physiological shear stress (PSS), high shear stress (HSS), and oscillatory shear stress (OSS) that induce vessel inward remodeling, stabilization, outward remodeling, or disease susceptibility, respectively. Combined with a publicly available database on EC transcriptomic responses to drug treatments, this approach inferred a regulatory network controlling EC states and made several notable predictions.
View Article and Find Full Text PDFClin Oral Investig
January 2025
Department of Restorative Dentistry, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan.
Objectives: To evaluate the shear bond strength (SBS) of universal cements (UCs) to dentin prepared with different diamond burs using various adhesive strategies.
Materials And Methods: One-hundred-twenty molars were prepared to expose the mid-coronal dentin. The teeth were divided into two groups according to diamond bur preparations: coarse and super-fine grit burs.
Alzheimers Dement
December 2024
University of Toronto, Toronto, ON, Canada.
Background: Drug discovery efforts in neurological diseases, such as Alzheimer's disease (AD), have had particularly poor outcomes due to the lack of models that capture the cerebral vasculature. There is an unmet need to develop models that capture the physiological challenge of overcoming the blood-brain barrier (BBB) and impacts of blood flow-induced shear stress. In this work, we use a microfluidic platform to model the cerebral vasculature in familial AD (fAD) using patient-derived brain endothelial-like cells (BECs) and neurons.
View Article and Find Full Text PDFPulmonary artery (PA) flow analysis is crucial for understanding the progression of pulmonary hypertension (PH). We hypothesized that PA flow characteristics vary according to PH etiology. In this study, we used 4D flow cardiovascular magnetic resonance imaging (CMR) to compare PA flow velocity and wall shear stress (WSS) between patients with pulmonary arterial hypertension (PAH) and those with heart failure with preserved ejection fraction and pulmonary hypertension (PH-HFpEF).
View Article and Find Full Text PDFCureus
December 2024
Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, JPN.
Lip ulcers associated with endotracheal tube fixation are a known complication in adults, but their prevalence in neonates and preterm infants remains unclear. We report a case of a right oral commissure ulcer that developed during endotracheal tube fixation at the right oral commissure and left lateral decubitus positioning in an extremely preterm infant with unilateral pulmonary interstitial emphysema (PIE). A male infant was born at 24 weeks and four days of gestation, weighing 696 gm.
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