Saponin-permeabilized fiber preparation in conjunction with respirometric oxidative phosphorylation analysis provides integrative assessment of mitochondrial function. Mitochondrial respiration in physiological and pathological states can reflect various regulatory influences including mitochondrial interactions, morphology and biochemistry.
1Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 2Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 3Department of Molecular Biophysics and Physiology, Rush University Medical Center, 4Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center
Described here is a method to directly measure calcium sparks, the elementary units of Ca2+ release from sarcoplasmic reticulum in intact skeletal muscle fibers. This method utilizes osmotic-stress-mediated triggering of Ca2+ release from ryanodine receptor in isolated muscle fibers. The dynamics and homeostatic capacity of intracellular Ca2+ signaling can be employed to assess muscle function in health and disease.
A methodology to estimate ventricular fiber orientations from in vivo images of patient heart geometries for personalized modeling is described. Validation of the methodology performed using normal and failing canine hearts demonstrate that that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.
Published January 8, 2013. Keywords: Bioengineering, Biomedical Engineering, Medicine, Anatomy, Physiology, Cardiology, Myocytes, Cardiac, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, MRI, Diffusion Magnetic Resonance Imaging, Cardiac Electrophysiology, computerized simulation (general), mathematical modeling (systems analysis), Cardiomyocyte, biomedical image processing, patient-specific modeling, Electrophysiology, simulation
1Randall and Cardiovascular Divisions, King’s College London, 2Division of Cardiology, School of Medicine, University of California San Diego
Primary mouse cardiomyocyte cultures are one of the pivotal tools for the investigation of myofibrillar organization and function. The following protocol describes the isolation and culture of primary cardiomyocytes from neonatal mouse hearts. The resulting cardiomyocyte cultures may be subsequently used for a variety of biomechanical, biochemical and cell-biological assays.
Published September 6, 2013. Keywords: Cellular Biology, Biomedical Engineering, Bioengineering, Molecular Biology, Cell Culture Techniques, Primary Cell Culture, Cell Culture Techniques, Primary Cell Culture, Cell Culture Techniques, Primary Cell Culture, Cell Culture Techniques, Disease Models, Animal, Models, Cardiovascular, Cell Biology, neonatal mouse, cardiomyocytes, isolation, culture, primary cells, NMC, heart cells, animal model
1Magdi Yacoub Institute, Imperial College London, 2National Heart and Lung Institute, Imperial College London, 3Australian Regenerative Medicine Institute, Monash University
Intramyocardial cell delivery in murine models of cardiovascular diseases, such as hypertension or myocardial infarction, is widely used to test the therapeutic potential of different cell types in regenerative studies. Therefore, a detailed description and a clear visualization of this surgical procedure will help to define the limits and advantages of cardiovascular cell therapeutic analyses in small rodents.
The generation of aligned myocardial tissue is a key requirement for adapting the recent advances in stem cell biology to clinically useful purposes. Herein we describe a microcontact printing approach for the precise control of cell shape and function. Using highly purified populations of embryonic stem cell derived cardiac progenitors, we then generate anisotropic functional myocardial tissue.
Published March 19, 2013. Keywords: Stem Cell Biology, Bioengineering, Biomedical Engineering, Medicine, Molecular Biology, Cellular Biology, Anatomy, Physiology, Tissue Engineering, Cardiology, Cell Biology, Embryonic Stem Cells, ESCs, Micropatterning, Microcontact Printing, Cell Alignment, Heart Progenitors, in vitro Differentiation, Transgenic Mice, Mouse Embryonic Stem Cells, stem cells, myocardial tissue, PDMS, FACS, flow cytometry, animal model
Here we describe a basic protocol for fluorescent labeling of different elements of heart tubes from larva and adult Drosophila melanogaster. These specimens are well-suited for imaging via fluorescent or confocal microscopy. This technique permits detailed structural analysis of the features of the hearts from a powerful model organism.
The presented method offers a way to detect functional effective cardiotropic autoantibodies in the plasma of patients with dilated cardiomyopathy, irrespective of the specific antigen, by analysing the impact of isolated patient immunoglobulin on cellular shortening and intracellular calcium transients in isolated rat cardiomyocytes.
Published March 8, 2013. Keywords: Immunology, Medicine, Cellular Biology, Molecular Biology, Biomedical Engineering, Physiology, Anatomy, Cardiology, cardiomyocytes, cell shortening, intracellular Ca2+, Fura-2, antibodies, dilated cardiomyopathy, DCM, IgG, cardiac proteins, Langendorff perfusion, electrode, immunoassay, assay, cell culture, animal model
1Department of Electrical and Computer Engineering, George Mason University, 2Sports Medicine Assessment, Research & Testing Laboratory, George Mason University, 3School of Physics, Astronomy, and Computational Sciences, George Mason University, 4Department of Bioengineering, George Mason University
We describe a new ultrasound-based vector tissue Doppler imaging technique to measure muscle contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities. This approach provides complementary measurements of dynamic muscle function and could lead to a better understanding of mechanisms underlying musculoskeletal disorders.
Published September 17, 2013. Keywords: Medicine, Anatomy, Physiology, Joint Diseases, Diagnostic Imaging, Muscle Contraction, ultrasonic applications, Doppler effect (acoustics), Musculoskeletal System, biomechanics, musculoskeletal kinematics, dynamic function, ultrasound imaging, vector Doppler, strain, strain rate
1Department of Biomedical Engineering, University of Iowa
Time-lapse microscopy and image processing techniques were used to observe and analyze fibroblast-mediated gel compaction and fibrin fiber realignment in an environmentally controlled bioreactor over a 48 hr period.