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https://www.readbyqxmd.com/read/28227911/an-implementation-for-the-simulation-of-cells-on-micro-post-arrays
#1
Duy T Truong, Christian Bahls, Barbara Nebe, Ursula van Rienen, Duy T Truong, Christian Bahls, Barbara Nebe, Ursula van Rienen, Duy T Truong, Christian Bahls, Ursula van Rienen, Barbara Nebe
The mechanical interaction between cells and their underlying substrates is important in understanding the processes that take place at an interface between biological tissue and the surface of implants. There have been numerous studies that examine these interactions both by experimental and numerical modeling. The bio-chemo-mechanical model for cell contractility by Deshpande et al. [1] has numerous applications and advantages. This work shows a way to implement this model in COMSOL MULTIPHYSICS® so it can be easily modified or extended...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227774/simulating-the-effects-of-growth-and-fiber-dispersion-on-the-electromechanical-response-of-a-cardiac-ventricular-wedge-affected-from-concentric-hypertrophy
#2
Fabrizio Del Bianco, Piero Colli Franzone, Simone Scacchi, Lorenzo Fassina, Fabrizio Del Bianco, Piero Colli Franzone, Simone Scacchi, Lorenzo Fassina, Lorenzo Fassina, Piero Colli Franzone, Fabrizio Del Bianco, Simone Scacchi
In this paper, we analyze the epicardial electromechanical response of an in silico cardiac ventricular wedge under both healthy and concentric hypertrophic conditions. This is achieved by taking into account the growth of the wedge thickness and the fiber dispersion that may follow. The electromechanical response is described in terms of some macroscopic measures, i.e. the action potential duration, the conduction velocity, the contractility and the contraction force. Our results suggest that growth reduces the action potential duration and conduction velocity, whilst it increases the contractility and contraction force, yielding an overall negative effect...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227117/altered-viscoelastic-properties-of-stroke-affected-muscles-estimated-using-ultrasound-shear-waves-preliminary-data
#3
Ghulam Rasool, Allison B Wang, William Z Rymer, Sabrina S M Lee, Ghulam Rasool, Allison B Wang, William Z Rymer, Sabrina S M Lee, Ghulam Rasool, Sabrina S M Lee, Allison B Wang, William Z Rymer
As a result of a brain injury such as stroke, the skeletal muscles may undergo numerous structural and functional alterations. These abnormal changes are linked to muscle weakness, joint contracture, and abnormal muscle tone and eventually, result in motor impairment. A subset of these alterations affects passive muscle stiffness, i.e., viscoelastic properties. However, in vivo estimation of changes in viscoelastic properties is a challenging task. Here, we used the shear wave velocity, estimated through ultrasound SuperSonic imaging (SSI), as a surrogate for viscoelastic properties...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225916/expression-profiles-of-enos-inos-and-microrna-27b-in-the-corpus-cavernosum-of-rats-submitted-to-chronic-alcoholism-and-diabetes-mellitus
#4
Joao Paulo da Cunha, Fermino Sanches Lizarte, Paulo Cezar Novais, Daniela Gattas, Camila Albuquerque Mello de Carvalho, Daniela Pretti da Cunha Tirapelli, Carlos Augusto Fernandes Molina, Luis Fernando Tirapelli, Silvio Tucci
Purpose: To evaluate the expression of endothelial and inducible NOS in addition to the miRNA-27b in the corpus cavernosum and peripheral blood of healthy rats, diabetic rats, alcoholic rats and rats with both pathologies. Methods: Forty eight Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D) and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study protein expressions of eNOS and iNOS by immunohistochemistry and expression of miRNA-27b in the corpus cavernosum and peripheral blood...
January 2017: Acta Cirúrgica Brasileira
https://www.readbyqxmd.com/read/28225202/cardiac-remodeling-in-preterm-infants-with-prolonged-exposure-to-a-patent-ductus-arteriosus
#5
Koert de Waal, Nilkant Phad, Nick Collins, Andrew Boyle
BACKGROUND: Sustained volume load due to a patent ductus arteriosus (PDA) leads to cardiac remodeling. Remodeling changes can become pathological and are associated with cardiovascular disease progression. Data on remodeling changes in preterm infants is not available. METHODS: Clinical and echocardiography data were collected in preterm infants <30 weeks gestation on postnatal day 3 and then every 7-14 days until closure of the ductus arteriosus. Images were analyzed using conventional techniques and speckle tracking...
February 22, 2017: Congenital Heart Disease
https://www.readbyqxmd.com/read/28224370/a-dual-mode-bioreactor-system-for-tissue-engineered-vascular-models
#6
N Bono, S Meghezi, M Soncini, M Piola, D Mantovani, Gianfranco Beniamino Fiore
In the past decades, vascular tissue engineering has made great strides towards bringing engineered vascular tissues to the clinics and, in parallel, obtaining in-lab tools for basic research. Herein, we propose the design of a novel dual-mode bioreactor, useful for the fabrication (construct mode) and in vitro stimulation (culture mode) of collagen-based tubular constructs. Collagen-based gels laden with smooth muscle cells (SMCs) were molded directly within the bioreactor culture chamber. Based on a systematic characterization of the bioreactor culture mode, constructs were subjected to 10% cyclic strain at 0...
February 21, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28224240/simulation-of-cell-substrate-traction-force-dynamics-in-response-to-soluble-factors
#7
Tao Liu
Finite element (FE) simulations of contractile responses of vascular muscular thin films (vMTFs) and endothelial cells resting on an array of microposts under stimulation of soluble factors were conducted in comparison with experimental measurements reported in the literature. Two types of constitutive models were employed in the simulations, i.e. smooth muscle cell type and non-smooth muscle cell type. The time histories of the effects of soluble factors were obtained via calibration against experimental measurements of contractile responses of tissues or cells...
February 21, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28223517/heart-failure-drug-changes-the-mechanoenzymology-of-the-cardiac-myosin-powerstroke
#8
John A Rohde, David D Thomas, Joseph M Muretta
Omecamtiv mecarbil (OM), a putative heart failure therapeutic, increases cardiac contractility. We hypothesize that it does this by changing the structural kinetics of the myosin powerstroke. We tested this directly by performing transient time-resolved FRET on a ventricular cardiac myosin biosensor. Our results demonstrate that OM stabilizes myosin's prepowerstroke structural state, supporting previous measurements showing that the drug shifts the equilibrium constant for myosin-catalyzed ATP hydrolysis toward the posthydrolysis biochemical state...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28223222/disrupting-the-key-circadian-regulator-clock-leads-to-age-dependent-cardiovascular-disease
#9
Faisal J Alibhai, Jonathan LaMarre, Cristine J Reitz, Elena V Tsimakouridze, Jeffrey T Kroetsch, Steffen-Sebastian Bolz, Alex Shulman, Samantha Steinberg, Thomas P Burris, Gavin Y Oudit, Tami A Martino
The circadian mechanism underlies daily rhythms in cardiovascular physiology and rhythm disruption is a major risk factor for heart disease and worse outcomes. However, the role of circadian rhythms is generally clinically unappreciated. Clock is a core component of the circadian mechanism and here we examine the role of Clock as a vital determinant of cardiac physiology and pathophysiology in aging. Clock(Δ19/Δ19) mice develop age-dependent increases in heart weight, hypertrophy, dilation, impaired contractility, and reduced myogenic responsiveness...
February 18, 2017: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/28222801/a-new-method-for-treating-fecal-incontinence-by-implanting-stem-cells-derived-from-human-adipose-tissue-preliminary-findings-of-a-randomized-double-blind-clinical-trial
#10
Arash Sarveazad, Graham L Newstead, Rezvan Mirzaei, Mohammad Taghi Joghataei, Mehrdad Bakhtiari, Asrin Babahajian, Bahar Mahjoubi
BACKGROUND: Anal sphincter defects are a major cause of fecal incontinence causing negative effects on daily life, social interactions, and mental health. Because human adipose-derived stromal/stem cells (hADSCs) are easier and safer to access, secrete high levels of growth factor, and have the potential to differentiate into muscle cells, we investigated the ability of hADSCs to improve anal sphincter incontinence. METHODS: The present randomized double-blind clinical trial was performed on patients with sphincter defects...
February 21, 2017: Stem Cell Research & Therapy
https://www.readbyqxmd.com/read/28222326/crossing-kingdoms-using-decellularized-plants-as-perfusable-tissue-engineering-scaffolds
#11
Joshua R Gershlak, Sarah Hernandez, Gianluca Fontana, Luke R Perreault, Katrina J Hansen, Sara A Larson, Bernard Y K Binder, David M Dolivo, Tianhong Yang, Tanja Dominko, Marsha W Rolle, Pamela J Weathers, Fabricio Medina-Bolivar, Carole L Cramer, William L Murphy, Glenn R Gaudette
Despite significant advances in the fabrication of bioengineered scaffolds for tissue engineering, delivery of nutrients in complex engineered human tissues remains a challenge. By taking advantage of the similarities in the vascular structure of plant and animal tissues, we developed decellularized plant tissue as a prevascularized scaffold for tissue engineering applications. Perfusion-based decellularization was modified for different plant species, providing different geometries of scaffolding. After decellularization, plant scaffolds remained patent and able to transport microparticles...
February 10, 2017: Biomaterials
https://www.readbyqxmd.com/read/28222167/emergence-and-development-of-gut-motility-in-the-chicken-embryo
#12
N R Chevalier, V Fleury, S Dufour, V Proux-Gillardeaux, A Asnacios
The gastrointestinal tract transports the food bolus by peristalsis. Gut motility starts at an early age in the developing embryo, well before it is required for nutrition of the organism. We present a comprehensive kinematic study of the emergence and physiological development of gut motility in all regions of the lower digestive tract of the chicken embryo from embryonic days E5 through E9. We characterized motility emergence time, propagation patterns, speed, frequency and amplitude of peristalsis waves...
2017: PloS One
https://www.readbyqxmd.com/read/28220640/multidimensional-contractile-reserve-predicts-adverse-outcome-in-patients-with-severe-systolic-heart-failure-a-4-year-follow-up-study
#13
Ioannis A Paraskevaidis, Ignatios Ikonomidis, Panagiotis Simitsis, John Parissis, Vasilios Stasinos, George Makavos, John Lekakis
AIMS: Left ventricular contractile reserve is a prognostic indicator for adverse outcome in patients with severe chronic heart failure with reduced ejection fraction (HFrEF). We investigated the dobutamine-induced changes of LV multidimensional deformation and their predictive value for cardiac mortality of patients with severe chronic HFrEF. METHODS AND RESULTS: In this prospective study, out of 130 patients with severe HFrEF who underwent a low-dose dobutamine stress echocardiography (LDSE) study using speckle tracking imaging, 100 patients were followed up for the occurrence of cardiac death over a period of 4 years...
February 21, 2017: European Journal of Heart Failure
https://www.readbyqxmd.com/read/28219442/eplerenone-for-early-cardiomyopathy-in-duchenne-muscular-dystrophy-results-of-a-two-year-open-label-extension-trial
#14
Subha V Raman, Kan N Hor, Wojciech Mazur, Xin He, John T Kissel, Suzanne Smart, Beth McCarthy, Sharon L Roble, Linda H Cripe
BACKGROUND: Cardiomyopathy is a leading cause of morbidity and mortality in boys with Duchenne muscular dystrophy (DMD). We recently showed in a 12-month double-blind randomized controlled trial that adding eplerenone to background medical therapy was cardioprotective in this population. The objective of this study was to evaluate the safety and efficacy of longer-term eplerenone therapy in boys with DMD. RESULTS: Eleven subjects (phase 1 baseline median [range] age: 13 [7 - 25] years) from the original 12-month trial at a single participating center were enrolled...
February 20, 2017: Orphanet Journal of Rare Diseases
https://www.readbyqxmd.com/read/28219356/bacopa-monnieri-extract-increases-rat-coronary-flow-and-protects-against-myocardial-ischemia-reperfusion-injury
#15
Sirintorn Srimachai, Sylvie Devaux, Celine Demougeot, Sarawut Kumphune, Nina D Ullrich, Ernst Niggli, Kornkanok Ingkaninan, Natakorn Kamkaew, C Norman Scholfield, Sompol Tapechum, Krongkarn Chootip
BACKGROUND: This study explored Bacopa monnieri, a medicinal Ayurvedic herb, as a cardioprotectant against ischemia/reperfusion injury using cardiac function and coronary flow as end-points. METHODS: In normal isolated rat hearts, coronary flow, left ventricular developed pressure, heart rate, and functional recovery were measured using the Langendorff preparation. Hearts were perfused with either (i) Krebs-Henseleit (normal) solution, (control), or with 30, 100 μg/ml B...
February 20, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28217949/clinical-impact-of-the-presence-of-macrophages-in-endomyocardial-biopsies-of-patients-with-dilated-cardiomyopathy
#16
Takafumi Nakayama, Yasuo Sugano, Tetsuro Yokokawa, Toshiyuki Nagai, Taka-Aki Matsuyama, Keiko Ohta-Ogo, Yoshihiko Ikeda, Hatsue Ishibashi-Ueda, Takeshi Nakatani, Nobuyuki Ohte, Satoshi Yasuda, Toshihisa Anzai
BACKGROUND: Dilated cardiomyopathy (DCM) is the most common cardiomyopathy and causes left ventricular enlargement and contractile dysfunction, with a poor prognosis. The mechanisms underlying the disease process have not been precisely identified, but recent evidence has suggested that the activation of myocardial inflammation is involved in the deterioration associated with the condition. METHODS AND RESULTS: Biopsy samples from 182 consecutive DCM patients were immunohistochemically stained with antibodies specific to CD3 (T lymphocytes), CD68 (whole macrophages), and CD163 (M2 macrophages), and each type of infiltrating cell was counted...
February 20, 2017: European Journal of Heart Failure
https://www.readbyqxmd.com/read/28217832/gestational-protein-restriction-study-of-the-probable-effects-on-cardiac-muscle-structure-and-function-in-adult-rats
#17
Mona G Amer, Nader M Mohamed, Aly A M Shaalan
Intrauterine growth restriction (IUGR) has been linked to heart disease in adulthood. This study aimed to examine the effect of gestational protein restriction during fetal and early postnatal life on the cardiac muscle structure and function in adult offspring. Pregnant female rats were randomly divided into two dietary groups: normal-protein diet (NP) and low-protein diet (LP). Fifteen male offspring from each group were included in the study. Offspring body weights were recorded at birth and monthly from weaning until 24 weeks of age while systolic blood pressure was measured weekly...
February 20, 2017: Histology and Histopathology
https://www.readbyqxmd.com/read/28217802/-comparison-of-agonists-induced-contraction-between-main-and-the-third-order-branches-of-pulmonary-arteries-in-rats
#18
Qiu-Hong Huang, Yun-Ping Mu, Fu-Rong Yan, Jie-Ling Zhu, Xiao-Ru Liu, Mo-Jun Lin
This study was designed to observe the differences between main pulmonary arteries and the third-order branches of pulmonary arteries in the contractile response to phenylephrine (Phen), endothelin-1 (ET-1) and potassium chloride (KCl). The vascular tension changes of main and the third-order branches of pulmonary arteries induced by KCl, ET-1 and Phen were recorded by traditional vascular tone detection methods and microvascular ring technique, respectively. The results showed that Phen could cause a significant contraction in main pulmonary arteries, but did not induce apparent contraction in the third-order branches of pulmonary arteries...
February 25, 2017: Sheng Li Xue Bao: [Acta Physiologica Sinica]
https://www.readbyqxmd.com/read/28215335/optogenetic-inhibition-of-apical-constriction-during-drosophila-embryonic-development
#19
G Guglielmi, S De Renzis
Morphogenesis of multicellular organisms is driven by changes in cell behavior, which happen at precise locations and defined developmental stages. Therefore, the studying of morphogenetic events would greatly benefit from tools that allow the perturbation of cell activity with spatial and temporal precision. We recently developed an optogenetic approach to modulate cell contractility with cellular precision and on fast (seconds) timescales during Drosophila embryogenesis. We present here a protocol to handle genetically engineered photosensitive Drosophila embryos and achieve light-mediated inhibition of apical constriction during tissue invagination...
2017: Methods in Cell Biology
https://www.readbyqxmd.com/read/28215181/effect-of-cellular-and-extracellular-pathology-assessed-by-t1-mapping-on-regional-contractile-function-in-hypertrophic-cardiomyopathy
#20
Peter P Swoboda, Adam K McDiarmid, Bara Erhayiem, Graham R Law, Pankaj Garg, David A Broadbent, David P Ripley, Tarique A Musa, Laura E Dobson, James R Foley, Graham J Fent, Stephen P Page, John P Greenwood, Sven Plein
BACKGROUND: Regional contractile dysfunction is a frequent finding in hypertrophic cardiomyopathy (HCM). We aimed to investigate the contribution of different tissue characteristics in HCM to regional contractile dysfunction. METHODS: We prospectively recruited 50 patients with HCM who underwent cardiovascular magnetic resonance (CMR) studies at 3.0 T including cine imaging, T1 mapping and late gadolinium enhancement (LGE) imaging. For each segment of the American Heart Association model segment thickness, native T1, extracellular volume (ECV), presence of LGE and regional strain (by feature tracking and tissue tagging) were assessed...
February 20, 2017: Journal of Cardiovascular Magnetic Resonance
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