Objective: Biomechanically, rupture of an Abdominal Aortic Aneurysm (AAA) occurs when the stress acting on the wall due to the blood pressure, exceeds the strength of the wall. Peak wall stress estimations, based on CT reconstruction, may be prone to observer variation. This study focuses on the robustness and reproducibility of AAA wall stress assessment and the relation with geometrical features of the AAA.
Methods: The AAAs of twenty patients were reconstructed by three operators. Both the peak and 99-percentile stress were used for intra- and inter-operator variability using the intraclass correlation coefficient (ICC). A regression analysis was performed to relate the stress parameters with the maximum diameter. Outliers were analyzed by their geometrical characteristics.
Results: The intra-operator ICC was 0.73-0.79 for the peak stress and 0.94 for the 99-percentile stress. The inter-operator ICC was 0.71 for the peak stress and 0.95 for the 99-percentile stress. A significant linear relation with the diameter was found only for the 99-percentile stress.
Conclusions: The 99-percentile stress is more reproducible than peak wall stress. A significant relation between wall stress and diameter was found. Other geometrical features had no statistical relation with high stress.
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http://dx.doi.org/10.1016/j.ejvs.2008.09.007 | DOI Listing |
Plant Cell Rep
January 2025
College of Life Sciences, Shanxi Normal University, Taiyuan, 031002, Shanxi, China.
N-terminal acetyltransferase Naa50 plays an important regulatory role in ovule development by indirectly promoting cell wall invertase 2/4 expression.
View Article and Find Full Text PDFLab Chip
January 2025
Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5000, FI-90014 Oulu, Finland.
A novel microfluidic platform was designed to study the cellular architecture of endothelial cells (ECs) in an environment replicating the 3D organization and flow of blood vessels. In particular, the platform was constructed to investigate EC defects in slow-flow venous malformations (VMs) under varying shear stress and flow conditions. The platform featured a standard microtiter plate footprint containing 32 microfluidic units capable of replicating wall shear stress (WSS) in normal veins and enabling precise control of shear stress and flow directionality without the need for complex pumping systems.
View Article and Find Full Text PDFJCI Insight
January 2025
Section of Vascular Surgery, Department of Surgery, and.
Abdominal aortic aneurysms (AAA) are a life-threatening cardiovascular disease for which there is a lack of effective therapy preventing aortic rupture. During AAA formation, pathological vascular remodeling is driven by vascular smooth muscle cell (VSMC) dysfunction and apoptosis, for which the mechanisms regulating loss of VSMCs within the aortic wall remain poorly defined. Using single-cell RNA-Seq of human AAA tissues, we identified increased activation of the endoplasmic reticulum stress response pathway, PERK/eIF2α/ATF4, in aortic VSMCs resulting in upregulation of an apoptotic cellular response.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, 832003, China.
Plants commonly undergo leaf morphoanatomy and composition modifications to cope with drought stress, and these tend to reduce mesophyll conductance to CO2 diffusion (gm), a key limitation to photosynthesis. The cell wall appears to play a crucial role in this reduction, yet the specific effect of cell wall compositions on gm and the underlying regulatory mechanisms of cell wall thickness (Tcw) variation are not well understood. In this study, we subjected cotton plants to varying levels of water deficit to investigate the impact of leaf cell wall composition and the arrangement patterns of microfibrils within cell walls on Tcw and leaf gas exchange.
View Article and Find Full Text PDFActa Neuropathol
January 2025
Department of Clinical Sciences, Lund Brain Injury Laboratory for Neurosurgical Research, Lund University, 222 20, Lund, Sweden.
Traumatic brain injury (TBI) often leads to impaired regulation of cerebral blood flow, which may be caused by pathological changes of the vascular smooth muscle cells (VSMCs) in the arterial wall. Moreover, these cerebrovascular changes may contribute to the development of various neurodegenerative disorders such as Alzheimer's-like pathologies that include amyloid beta aggregation. Despite its importance, the pathophysiological mechanisms responsible for VSMC dysfunction after TBI have rarely been evaluated.
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