In mammalian ventricular cardiomyocytes, invaginations of the surface membrane form the transverse tubular system (T-system), which consists of transverse tubules (TTs) that align with sarcomeres and Z-lines as well as longitudinal tubules (LTs) that are present between Z-lines in some species. In many cardiac disease etiologies, the T-system is perturbed, which is believed to promote spatially heterogeneous, dyssynchronous Ca release and inefficient contraction. In general, T-system characterization approaches have been directed primarily at isolated cells and do not detect subcellular T-system heterogeneity. Here, we present MatchedMyo, a matched-filter-based algorithm for subcellular T-system characterization in isolated cardiomyocytes and millimeter-scale myocardial sections. The algorithm utilizes "filters" representative of TTs, LTs, and T-system absence. Application of the algorithm to cardiomyocytes isolated from rat disease models of myocardial infarction (MI), dilated cardiomyopathy induced via aortic banding, and sham surgery confirmed and quantified heterogeneous T-system structure and remodeling. Cardiomyocytes from post-MI hearts exhibited increasing T-system disarray as proximity to the infarct increased. We found significant (p < 0.05, Welch's t-test) increases in LT density within cardiomyocytes proximal to the infarct (12 ± 3%, data reported as mean ± SD, n = 3) versus sham (4 ± 2%, n = 5), but not distal to the infarct (7 ± 1%, n = 3). The algorithm also detected decreases in TTs within 5° of the myocyte minor axis for isolated aortic banding (36 ± 9%, n = 3) and MI cardiomyocytes located intermediate (37 ± 4%, n = 3) and proximal (34 ± 4%, n = 3) to the infarct versus sham (57 ± 12%, n = 5). Application of bootstrapping to rabbit MI tissue revealed distal sections comprised 18.9 ± 1.0% TTs, whereas proximal sections comprised 10.1 ± 0.8% TTs (p < 0.05), a 46.6% decrease. The matched-filter approach therefore provides a robust and scalable technique for T-system characterization from isolated cells through millimeter-scale myocardial sections.
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http://dx.doi.org/10.1016/j.bpj.2019.03.010 | DOI Listing |
NMR Biomed
December 2024
Department of Neurology, Henry Ford Hospital, Detroit, MI, USA.
Sci Rep
January 2024
Division of Medical Physics, Department of Diagnostic and Interventional Radiology, Faculty of Medicine, University Medical Center Freiburg, University of Freiburg, Killianstr. 5a, 79106, Freiburg, Germany.
Magnetic resonance imaging (MRI) provides a multitude of techniques to detect and characterize myocardial infarction. To correlate MRI findings with histology, in most cases terminal animal studies are performed; however, precise extraction and spatial correlation of myocardial tissue samples to MRI image data is difficult. In this proof of concept study, we present a 3D-printing technique to facilitate the extraction of tissue samples from myocardial regions.
View Article and Find Full Text PDFFront Cardiovasc Med
March 2023
Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States.
Background: Contemporary advances in low-field magnetic resonance imaging systems can potentially widen access to cardiovascular magnetic resonance (CMR) imaging. We present our initial experience in building a comprehensive CMR protocol on a commercial 0.55 T system with a gradient performance of 26 mT/m amplitude and 45 T/m/s slew rate.
View Article and Find Full Text PDFNeurology
January 2023
From the Sorbonne Université (A.L.D.S.,M.D.P.D., L.N., M.D.P.D., J.L., M.G., S.L., Francesca Branzoli), Inserm, CNRS, Paris Brain Institute-Institut du Cerveau (ICM), Paris, France. Equipe labellisée LNCC; Service de Neurologie 2-Mazarin (A.L.D.S.,M.D.P.D., M.D.P.D., C.D.), AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Paris, France; Service de Neuroradiologie Diagnostique et Interventionnelle (L.N., D.G., S.L.), AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Paris, France; Neurology Unit (G.B.), IRCCS San Raffaele Scientific Institute, Milan, Italy; Centre de NeuroImagerie de Recherche (CENIR) (R.V., S.L., Francesca Branzoli), Institut du Cerveau (ICM), Paris, France; Service de Neurochirurgie (L.C., B.B.), AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Paris, France; Service de Biochimie Métabolique (C.P.), AP-HP, Hôpital Necker, Paris, France; Laboratoire R Escourolle (J.L.), AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Paris, France; Drug Development Department (DITEP) (C.B.), Gustave Roussy, Villejuif, France; Service de Radiologie (J.S.), Fondation Ophtalmologique Adolphe de Rothschild, Paris, France; Radiotherapy Department (F.D.), Gustave Roussy University Hospital, Villejuif, Cedex, France; Center for Magnetic Resonance Research (D.K.D., M.M.), Department of Radiology, Minneapolis, MN; and OncoNeuroTek Tumor Bank (M.D.P.D.), Institut du Cerveau et de la Moelle épinière (ICM), Paris, France.
Background And Objectives: D-2-hydroxyglutarate (2HG) characterizes -mutant gliomas and can be detected and quantified with edited MRS (MEGA-PRESS). In this study, we investigated the clinical, radiologic, and molecular parameters affecting 2HG levels.
Methods: MEGA-PRESS data were acquired in 71 patients with glioma (24 untreated, 47 treated) on a 3 T system.
Nanomaterials (Basel)
August 2022
Faculty of Mechanical and Automotive Engineering Technology, Universiti Malaysia Pahang, Pekan 26600, Malaysia.
Nanofluids are identified as advanced working fluids in the solar energy conversion field with superior heat transfer characteristics. This research work introduces carbon-based diamond nanomaterial and Therminol55 oil-based nanofluids for implementation in a concentrated photovoltaic/thermal (CPV/T) solar collector. This study focuses on the experimental formulation, characterization of properties, and performance evaluation of the nanofluid-based CPV/T system.
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