William J. Karlon

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Endothelial cells elongate and align with the direction of applied fluid shear stress. Previously, automated methods for analysis of cell orientation distribution have used Fourier- or fractal-based methods. We used intensity gradients in images of control and sheared endothelial cells to measure orientation distributions. Automated measurements of mean(More)
Brief ischemic periods lead to myocardial dysfunction without myocardial infarction. It has been shown that expression of inducible HSP70 in hearts of transgenic mice leads to decreased infarct size, but it remains unclear if HSP70 can also protect against myocardial dysfunction after brief ischemia. To investigate this question, we developed a mouse model(More)
Quantitative assessment of myofiber disarray associated with diseases such as familial hypertrophic cardiomyopathy (FHC) can be performed by estimating local angular deviation of fiber orientation in histologic sections. The large number of measurements required to estimate angular deviation prohibits manual measurement. We describe methods for automated(More)
A hallmark of certain cardiac diseases such as familial hypertrophic cardiomyopathy is focal myofiber disarray. Regional ventricular dysfunction occurs in human subjects with hypertrophic cardiomyopathy; however, no direct evidence exists to correlate regional dysfunction with myofiber disarray. We used a transgenic mouse, which exhibits regional myofiber(More)
The study objectives were to quantify the time- and magnitude-dependence of flow-induced alignment in vascular smooth muscle cells (SMC) and to identify pathways related to the orientation process. Using an intensity gradient method, we demonstrated that SMC aligned in the direction perpendicular to applied shear stress, which contrasts with parallel(More)
Although large collagen fibers in myocardial infarct scar are highly organized, little is known about mechanisms controlling this organization. The preexisting extracellular matrix may act as a scaffold along which fibroblasts migrate. Conversely, deformation within the ischemic area could guide fibroblasts so new collagen is oriented to counteract the(More)
The most widely used defibrillation dosing strategy is that adopted by the American Heart Association in 1986. However, several alternative dosing strategies have been proposed to match delivered energy to the individual requirements of defibrillation subjects. In this study, two-dimensional finite element methods are used to investigate the performance of(More)
CONTEXT Flow cytometry is often applied to minimal residual disease (MRD) testing in hematolymphoid neoplasia. Because flow-based MRD tests are developed in the laboratory, testing methodologies and lower levels of detection (LODs) are laboratory dependent. OBJECTIVES To broadly survey flow cytometry laboratories about MRD testing in laboratories, if(More)
Karlon, William J., Andrew D. McCulloch, James W. Covell, John J. Hunter, and Jeffrey H. Omens. Regional dysfunction correlates with myofiber disarray in transgenic mice with ventricular expression of ras. Am. J. Physiol. Heart Circ. Physiol. 278: H898–H906, 2000.—A hallmark of certain cardiac diseases such as familial hypertrophic cardiomyopathy is focal(More)
CONTEXT -Variability in testing for antineutrophil cytoplasmic antibodies (ANCAs) contributes to confusion and controversy related to testing for vasculitis and other ANCA-associated diseases. OBJECTIVES -To survey laboratory testing practices regarding ANCA testing and to investigate differences in testing algorithms. DESIGN -Supplemental questions(More)
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