scholarly journals Quantification of Myocyte Disarray in Human Cardiac Tissue

2021 ◽  
Vol 12 ◽  
Author(s):  
Francesco Giardini ◽  
Erica Lazzeri ◽  
Giulia Vitale ◽  
Cecilia Ferrantini ◽  
Irene Costantini ◽  
...  
Keyword(s):  
Spatial Scale ◽  
Cardiac Tissue ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Structural Data ◽  
Multi Scale ◽  
Tissue Organization ◽  
Human Cardiac Tissue ◽  
Microscopy Techniques ◽  
Scale Of Analysis

Proper three-dimensional (3D)-cardiomyocyte orientation is important for an effective tension production in cardiac muscle. Cardiac diseases can cause severe remodeling processes in the heart, such as cellular misalignment, that can affect both the electrical and mechanical functions of the organ. To date, a proven methodology to map and quantify myocytes disarray in massive samples is missing. In this study, we present an experimental pipeline to reconstruct and analyze the 3D cardiomyocyte architecture in massive samples. We employed tissue clearing, staining, and advanced microscopy techniques to detect sarcomeres in relatively large human myocardial strips with micrometric resolution. Z-bands periodicity was exploited in a frequency analysis approach to extract the 3D myofilament orientation, providing an orientation map used to characterize the tissue organization at different spatial scales. As a proof-of-principle, we applied the proposed method to healthy and pathologically remodeled human cardiac tissue strips. Preliminary results suggest the reliability of the method: strips from a healthy donor are characterized by a well-organized tissue, where the local disarray is log-normally distributed and slightly depends on the spatial scale of analysis; on the contrary, pathological strips show pronounced tissue disorganization, characterized by local disarray significantly dependent on the spatial scale of analysis. A virtual sample generator is developed to link this multi-scale disarray analysis with the underlying cellular architecture. This approach allowed us to quantitatively assess tissue organization in terms of 3D myocyte angular dispersion and may pave the way for developing novel predictive models based on structural data at cellular resolution.

Abstract 020: Cell-sheet-based Bioengineered Human Cardiac Tissue Using Pluripotent Stem Cells For Heart Repair And Disease Models

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Katsuhisa Matsuura ◽  
Tatsuya Shimizu ◽  
Nobuhisa Hagiwara ◽  
Teruo Okano
Keyword(s):  
Cardiac Tissue ◽  
Subcutaneous Tissue ◽  
Cell Sheet ◽  
Three Dimensional ◽  
Embryoid Bodies ◽  
Cardiac Differentiation ◽  
Cardiac Cell ◽  
Cell Sheets ◽  
High Efficient ◽  
Human Cardiac Tissue

We have developed an original scaffold-free tissue engineering approach, “cell sheet engineering”, and this technology has been already applied to regenerative medicine of various organs including heart. As the bioengineered three-dimensional cardiac tissue is expected to not only function for repairing the broad injured heart but also to be the practicable heart tissue models, we have developed the cell sheet-based perfusable bioengineered three-dimensional cardiac tissue. Recently we have also developed the unique suspension cultivation system for the high-efficient cardiac differentiation of human iPS cells. Fourteen-day culture with the serial treatments of suitable growth factors and a small compound in this stirring system with the suitable dissolved oxygen concentration produced robust embryoid bodies that showed the spontaneous beating and were mainly composed of cardiomyocytes (~80%). When these differentiated cells were cultured on temperature-responsive culture dishes after the enzymatic dissociation, the spontaneous and synchronous beating was observed accompanied with the intracellular calcium influx all over the area even after cell were detached from culture dishes as cell sheets by lowering the culture temperature. The cardiac cell sheets were mainly composed of cardiomyocytes (~80%) and partially mural cells (~20%). Furthermore, extracellular action potential propagation was observed between cell sheets when two cardiac cell sheets were partially overlaid, and this propagation was inhibited by the treatment with some anti-arrhythmic drugs. When the triple layered cardiac tissue was transplanted onto the subcutaneous tissue of nude rats, the spontaneous pulsation was observed over 2 months and engrafted cardiomyocytes were vascularized with the host tissue-derived endothelial cells. These findings suggest that cardiac cell sheets formed by hiPSC-derived cardiomyocytes might have sufficient properties for the creation of thickened cardiac tissue. Now we are developing the vascularized thickened human cardiac tissue by the repeated layering of cardiac cell sheets on the artificial vascular bed in vitro.

scholarly journals Three‐dimensional bioprinting human cardiac tissue chips of using a painting needle method

2019 ◽  
Vol 116 (11) ◽  
pp. 3136-3142 ◽  
Author(s):  
Shohei Chikae ◽  
Akifumi Kubota ◽  
Haruka Nakamura ◽  
Atsushi Oda ◽  
Akihiro Yamanaka ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Three Dimensional ◽  
Human Cardiac Tissue

Multi-Scale Simulation of MBE-Grown SiC/Si Nanostructures

2006 ◽  
Vol 527-529 ◽  
pp. 315-318 ◽  
Author(s):  
Alexander A. Schmidt ◽  
Yuri V. Trushin ◽  
K.L. Safonov ◽  
V.S. Kharlamov ◽  
Dmitri V. Kulikov ◽  
...  
Keyword(s):  
Kinetic Monte Carlo ◽  
Spatial Scales ◽  
Cluster Formation ◽  
Three Dimensional ◽  
Bulk Diffusion ◽  
Simulation Method ◽  
Atomic Scale ◽  
Rate Equations ◽  
Surface Evolution ◽  
Multi Scale

The main obstacle for the implementation of numerical simulation for the prediction of the epitaxial growth is the variety of physical processes with considerable differences in time and spatial scales taking place during epitaxy: deposition of atoms, surface and bulk diffusion, nucleation of two-dimensional and three-dimensional clusters, etc. Thus, it is not possible to describe all of them in the framework of a single physical model. In this work there was developed a multi-scale simulation method for molecular beam epitaxy (MBE) of silicon carbide nanostructures on silicon. Three numerical methods were used in a complex: Molecular Dynamics (MD), kinetic Monte Carlo (KMC), and the Rate Equations (RE). MD was used for the estimation of kinetic parameters of atoms at the surface, which are input parameters for other simulation methods. The KMC allowed the atomic-scale simulation of the cluster formation, which is the initial stage of the SiC growth, while the RE method gave the ability to study the growth process on a longer time scale. As a result, a full-scale description of the surface evolution during SiC formation on Si substrates was developed.

scholarly journals Spatial Scale Dependence of Ecological Factors That Regulate Functional and Phylogenetic Assembly in a Mediterranean High Mountain Grassland

2021 ◽  
Vol 9 ◽  
Author(s):  
David S. Pescador ◽  
Francesco de Bello ◽  
Jesús López-Angulo ◽  
Fernando Valladares ◽  
Adrián Escudero
Keyword(s):  
Global Warming ◽  
Organic Carbon ◽  
Spatial Scale ◽  
Community Assembly ◽  
Species Interactions ◽  
Species Turnover ◽  
Spatial Scales ◽  
Ecological Factors ◽  
Functional Heterogeneity ◽  
Multi Scale

Understanding how functional and phylogenetic patterns vary among scales and along ecological gradients within a given species pool is critical for inferring community assembly processes. However, we lack a clear understanding of these patterns in stressful habitats such as Mediterranean high mountains where ongoing global warming is expected to affect species fitness and species interactions, and subsequently species turnover. In this study, we investigated 39 grasslands with the same type of plant community and very little species turnover across an elevation gradient above the treeline at Sierra de Guadarrama National Park in central Spain. In particular, we assessed functional and phylogenetic patterns, including functional heterogeneity, using a multi-scale approach (cells, subplots, and plots) and determined the relevance of key ecological factors (i.e., elevation, potential solar radiation, pH, soil organic carbon, species richness, and functional heterogeneity) that affect functional and phylogenetic patterns at each spatial scale. Overall, at the plot scale, coexisting species tended to be more functionally and phylogenetically similar. By contrast, at the subplot and cell scales, species tended to be more functionally different but phylogenetically similar. Functional heterogeneity at the cell scale was comparable to the variation across plots along the gradient. The relevance of ecological factors that regulate diversity patterns varied among spatial scales. An increase in elevation resulted in functional clustering at larger scales and phylogenetic overdispersion at a smaller scale. The soil pH and organic carbon levels exhibited complex functional patterns, especially at small spatial scales, where an increase in pH led to clustering patterns for the traits related to the leaf economic spectrum (i.e., foliar thickness, specific leaf area, and leaf dry matter content). Our findings confirm the presence of primary environmental filters (coldness and summer drought at our study sites) that constrain the regional species pool, suggesting the presence of additional assembly mechanisms that act at the smallest scale (e.g., micro-environmental gradients and/or species interactions). Functional and phylogenetic relatedness should be determined using a multi-scale approach to help interpret community assembly processes and understand the initial community responses to environmental changes, including ongoing global warming.

scholarly journals A three-dimensional hybrid pacemaker electrode seamlessly integrates into engineered, functional human cardiac tissue in vitro

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Tobias Weigel ◽  
Tobias Schmitz ◽  
Tobias Pfister ◽  
Sabine Gaetzner ◽  
Maren Jannasch ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Three Dimensional ◽  
Human Cardiac Tissue

scholarly journals Iterative guided image fusion

2016 ◽  
Vol 2 ◽  
pp. e80 ◽  
Author(s):  
Alexander Toet
Keyword(s):  
Image Fusion ◽  
Spatial Scale ◽  
Spatial Scales ◽  
Small Scale ◽  
Computationally Efficient ◽  
Multi Scale ◽  
Saliency Maps ◽  
Spatial Consistency ◽  
Guided Filtering ◽  
Fusion Scheme

We propose a multi-scale image fusion scheme based on guided filtering. Guided filtering can effectively reduce noise while preserving detail boundaries. When applied in an iterative mode, guided filtering selectively eliminates small scale details while restoring larger scale edges. The proposed multi-scale image fusion scheme achieves spatial consistency by using guided filtering both at the decomposition and at the recombination stage of the multi-scale fusion process. First, size-selective iterative guided filtering is applied to decompose the source images into approximation and residual layers at multiple spatial scales. Then, frequency-tuned filtering is used to compute saliency maps at successive spatial scales. Next, at each spatial scale binary weighting maps are obtained as the pixelwise maximum of corresponding source saliency maps. Guided filtering of the binary weighting maps with their corresponding source images as guidance images serves to reduce noise and to restore spatial consistency. The final fused image is obtained as the weighted recombination of the individual residual layers and the mean of the approximation layers at the coarsest spatial scale. Application to multiband visual (intensified) and thermal infrared imagery demonstrates that the proposed method obtains state-of-the-art performance for the fusion of multispectral nightvision images. The method has a simple implementation and is computationally efficient.

scholarly journals A tool for multi-scale modelling of the renal nephron

2011 ◽  
Vol 1 (3) ◽  
pp. 417-425 ◽  
Author(s):  
David P. Nickerson ◽  
Jonna R. Terkildsen ◽  
Kirk L. Hamilton ◽  
Peter J. Hunter
Keyword(s):  
Mathematical Model ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Scale Model ◽  
Model Description ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Multi Scale ◽  
The Mathematical Model

We present the development of a tool, which provides users with the ability to visualize and interact with a comprehensive description of a multi-scale model of the renal nephron. A one-dimensional anatomical model of the nephron has been created and is used for visualization and modelling of tubule transport in various nephron anatomical segments. Mathematical models of nephron segments are embedded in the one-dimensional model. At the cellular level, these segment models use models encoded in CellML to describe cellular and subcellular transport kinetics. A web-based presentation environment has been developed that allows the user to visualize and navigate through the multi-scale nephron model, including simulation results, at the different spatial scales encompassed by the model description. The Zinc extension to Firefox is used to provide an interactive three-dimensional view of the tubule model and the native Firefox rendering of scalable vector graphics is used to present schematic diagrams for cellular and subcellular scale models. The model viewer is embedded in a web page that dynamically presents content based on user input. For example, when viewing the whole nephron model, the user might be presented with information on the various embedded segment models as they select them in the three-dimensional model view. Alternatively, the user chooses to focus the model viewer on a cellular model located in a particular nephron segment in order to view the various membrane transport proteins. Selecting a specific protein may then present the user with a description of the mathematical model governing the behaviour of that protein—including the mathematical model itself and various simulation experiments used to validate the model against the literature.

Engineering a functional three-dimensional human cardiac tissue model for drug toxicity screening

2017 ◽  
Vol 9 (2) ◽  
pp. 025011 ◽  
Author(s):  
Hong Fang Lu ◽  
Meng Fatt Leong ◽  
Tze Chiun Lim ◽  
Ying Ping Chua ◽  
Jia Kai Lim ◽  
...  
Keyword(s):  
Drug Toxicity ◽  
Cardiac Tissue ◽  
Three Dimensional ◽  
Toxicity Screening ◽  
Tissue Model ◽  
Human Cardiac Tissue

scholarly journals Multi-scale Cover Selection by White-tailed Deer, Odocoileus virginianus, in an Agro-forested Landscape

2009 ◽  
Vol 123 (1) ◽  
pp. 32
Author(s):  
Tim L. Hiller ◽  
Henry Campa ◽  
Scott R. Winterstein
Keyword(s):  
Spatial Scale ◽  
Odocoileus Virginianus ◽  
Resource Selection ◽  
Selection Process ◽  
Spatial Scales ◽  
Relative Importance ◽  
Multi Scale ◽  
South Central ◽  
Hierarchical Selection ◽  
And Behavior

Resource selection studies are commonly conducted at a single spatial scale, but this likely does not fully or accurately assess the hierarchical selection process used by animals. We used a multi-spatial scale approach to quantify White-tailed Deer (Odocoileus virginianus) cover selection in south-central Michigan during 2004–2006 by varying definitions of use and availability and ranking the relative importance of cover types under each study design. The number of cover types assigned as selected (proportional use > proportional availability) decreased from coarse (landscape level) to fine (within home range) scales, although at finer scales, selection seemed to be more consistent. Although the relative importance changed substantially across spatial scales, two cover types (conifers, upland deciduous forests) were consistently ranked as the two most important, providing strong evidence of their value to deer in the study area. Testing for resource selection patterns using a multi-spatial scale approach would provide additional insight into the ecology and behavior of a particular species.

Sign in / Sign up

Export Citation Format

Share Document