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https://www.readbyqxmd.com/read/28100834/soft-robotic-sleeve-supports-heart-function
#1
Ellen T Roche, Markus A Horvath, Isaac Wamala, Ali Alazmani, Sang-Eun Song, William Whyte, Zurab Machaidze, Christopher J Payne, James C Weaver, Gregory Fishbein, Joseph Kuebler, Nikolay V Vasilyev, David J Mooney, Frank A Pigula, Conor J Walsh
There is much interest in form-fitting, low-modulus, implantable devices or soft robots that can mimic or assist in complex biological functions such as the contraction of heart muscle. We present a soft robotic sleeve that is implanted around the heart and actively compresses and twists to act as a cardiac ventricular assist device. The sleeve does not contact blood, obviating the need for anticoagulation therapy or blood thinners, and reduces complications with current ventricular assist devices, such as clotting and infection...
January 18, 2017: Science Translational Medicine
https://www.readbyqxmd.com/read/28097776/molecular-mechanisms-underlying-deoxy-adp-pi-activation-of-pre-powerstroke-myosin
#2
Sarah G Nowakowski, Michael Regnier, Valerie Daggett
Myosin activation is a viable approach to treat systolic heart failure. We previously demonstrated that striated muscle myosin is a promiscuous ATPase that can use most nucleoside triphosphates as energy substrates for contraction. When 2-deoxy ATP (dATP) is used, it acts as a myosin activator, enhancing cross-bridge binding and cycling. In vivo, we have demonstrated that elevated dATP levels increase basal cardiac function and rescues function of infarcted rodent and pig hearts. Here we investigate the molecular mechanism underlying this physiological effect...
January 18, 2017: Protein Science: a Publication of the Protein Society
https://www.readbyqxmd.com/read/28090140/influence-of-warm-up-duration-and-recovery-interval-prior-to-exercise-on-anaerobic-performance
#3
M Frikha, N Chaâri, N Mezghanni, N Souissi
The purpose of the study was to determine the impact of different active warm-up (AWU) durations and the rest interval separating it from exercise on anaerobic performance. Eleven male physical education students (22.6 ± 2.52 years; 179.2 ± 4.3 cm; 82.5 ± 9.7 kg; mean ± SD) participated in a cross-over randomized study, and they all underwent the Wingate test after three AWU durations: 5 min (AWU5), 15 min (AWU15) and 20 min (AWU20), with recovery (WREC) or without a recovery interval (NREC) separating the AWU and anaerobic exercise performance...
December 2016: Biology of Sport
https://www.readbyqxmd.com/read/28077597/muscle-developmental-defects-in-heterogeneous-nuclear-ribonucleoprotein-a1-knockout-mice
#4
Ting-Yuan Liu, Yu-Chia Chen, Yuh-Jyh Jong, Huai-Jen Tsai, Chien-Chin Lee, Ya-Sian Chang, Jan-Gowth Chang, Yung-Fu Chang
Heterogeneous ribonucleoprotein A1 (hnRNP A1) is crucial for regulating alternative splicing. Its integrated function within an organism has not, however, been identified. We generated hnRNP A1 knockout mice to study the role of hnRNP A1 in vivo The knockout mice, hnRNP A1(-/-), showed embryonic lethality because of muscle developmental defects. The blood pressure and heart rate of the heterozygous mice were higher than those of the wild-type mice, indicating heart function defects. We performed mouse exon arrays to study the muscle development mechanism...
January 2017: Open Biology
https://www.readbyqxmd.com/read/28068381/impairment-of-excitation-contraction-coupling-in-right-ventricular-hypertrophied-muscle-with-fibrosis-induced-by-pulmonary-artery-banding
#5
Yoichiro Kusakari, Takashi Urashima, Daisuke Shimura, Erika Amemiya, Genki Miyasaka, Shunsuke Yokota, Yoshitaka Fujimoto, Toru Akaike, Takahiro Inoue, Susumu Minamisawa
Interstitial myocardial fibrosis is one of the factors responsible for dysfunction of the heart. However, how interstitial fibrosis affects cardiac function and excitation-contraction coupling (E-C coupling) has not yet been clarified. We developed an animal model of right ventricular (RV) hypertrophy with fibrosis by pulmonary artery (PA) banding in rats. Two, four, and six weeks after the PA-banding operation, the tension and intracellular Ca2+ concentration of RV papillary muscles were simultaneously measured (n = 33)...
2017: PloS One
https://www.readbyqxmd.com/read/28057868/glucocorticoid-receptor-alters-isovolumetric-contraction-and-restrains-cardiac-fibrosis
#6
Rachel Richardson, Emma Batchen, Adrian Thomson, Rowan Darroch, Xinlu Pan, Eva Rog-Zielinska, Wiktoria Wyrzykowska, Kathleen Scullion, Emad A S Al-Dujaili, Mary Diaz, Carmel Moran, Chris J Kenyon, Gillian A Gray, Karen Chapman
Corticosteroids directly affect the heart and vasculature and are implicated in the pathogenesis of heart failure. Attention has focussed upon the role of the mineralocorticoid receptor (MR) in mediating pro-fibrotic and other adverse effects of corticosteroids upon the heart. In contrast, the role of the glucocorticoid receptor (GR) in the heart and vasculature is less well understood. We addressed this in mice with cardiomyocyte and vascular smooth muscle deletion of GR (SMGRKO mice). Survival of SMGRKO mice to weaning was reduced compared with littermate controls...
January 5, 2017: Journal of Endocrinology
https://www.readbyqxmd.com/read/28006945/neonatal-capsaicin-administration-impairs-postnatal-development-of-the-cardiac-chronotropy-and-inotropy-in-rats
#7
J Kuncová, A Jirkovská, J Švíglerová, M Marková, D Meireles, M Čedíková
The present study evaluated the impact of neonatal administration of capsaicin (neurotoxin from red hot pepper used for sensory denervation) on postnatal development of the heart rate and ventricular contractility. In the rats subjected to capsaicin administration (100 mg/kg) on postnatal days 2 and 3 and their vehicle-treated controls at the ages of 10 to 90 days, function of the sympathetic innervation of the developing heart was characterized by evaluation of chronotropic responses to metipranolol and atropine, norepinephrine concentrations in the heart, and norepinephrine release from the heart atria...
December 22, 2016: Physiological Research
https://www.readbyqxmd.com/read/28006942/propofol-induced-mitochondrial-and-contractile-dysfunction-of-the-rat-ventricular-myocardium
#8
M Grundmanová, D Jarkovská, A Süß, Z Tůma, M Marková, Z Grundman, A El-Kadi, M Čedíková, M Štengl, J Kuncová
Propofol is a short-acting hypnotic agent used in human medicine for sedation and general anesthesia. Its administration can be associated with serious cardiovascular side-effects that include decrease in arterial blood pressure and cardiac output. The aim of the present study was to evaluate propofol effects on mitochondrial respiration, myocardial contractility and electrophysiology in the same samples isolated from the heart ventricles of adult rats. Mitochondrial oxygen consumption was measured in permeabilized samples dissected from free walls of both ventricles using high-resolution respirometry...
December 22, 2016: Physiological Research
https://www.readbyqxmd.com/read/27990123/brief-rewarming-blunts-hypothermia-induced-alterations-in-sensation-motor-drive-and-cognition
#9
Marius Brazaitis, Henrikas Paulauskas, Albertas Skurvydas, Henning Budde, Laura Daniuseviciute, Nerijus Eimantas
Background: It is well known that cold exposure experienced during occupational or recreational activities may adversely affect motor, cognitive performance, and health. Most research has used prolonged passive external rewarming modalities and focused on the direct effects on the kinetics of physiological and psychological responses in hypothermic subjects. However, the brief whole body rewarming effects on physiological and psychological responses in parallel with functional consequences on cognitive and neurophysiological functions have not been investigated...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27984313/electrical-stimulation-of-artificial-heart-muscle-a-look-into-the-electrophysiological-and-genetic-implications
#10
Mohamed A Mohamed, Jose F Islas, Robert J Schwartz, Ravi K Birla
Development of tissue-engineered hearts for treatment of myocardial infarction or biological pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. In order to further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously...
December 13, 2016: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/27983818/structural-and-functional-effects-of-cardiomyopathy-causing-mutations-in-the-troponin-t-binding-region-of-cardiac-tropomyosin
#11
Alexander M Matyushenko, Daniil V Shchepkin, Galina V Kopylova, Katerina E Popruga, Natalya V Artemova, Anastasia V Pivovarova, Sergey Y Bershitsky, Dmitrii I Levitsky
Hypertrophic cardiomyopathy (HCM) is a severe heart disease caused by missense mutations in genes encoding sarcomeric proteins of cardiac muscle. Many of these mutations are identified in the gene encoding the cardiac isoform of tropomyosin (Tpm), an α-helical coiled-coil actin-binding protein that plays a key role in Ca(2+)-regulated contraction of cardiac muscle. We employed various methods to characterize structural and functional features of recombinant human Tpm species carrying HCM mutations that lie either within the troponin T-binding region in the C-terminal part of Tpm (E180G, E180V, and L185R) or near this region (I172T)...
December 16, 2016: Biochemistry
https://www.readbyqxmd.com/read/27959833/adaptive-spectro-temporal-filtering-for-electrocardiogram-signal-enhancement
#12
Diana Tobon Vallejo, Tiago Falk
Advances in low-cost portable electrocardiogram (ECG) devices have opened doors for numerous new applications, including fitness tracking, remote health, and peak athletic performance monitoring, to name a few. Many such devices, however, have been shown to be highly contaminated by movement and/or muscle contraction artifacts, which in turn, can lead to erroneous heart rate and heart rate variability (HRV) analyses. Here, we propose a new denoising method based on adaptive spectrotemporal filtering for ECG enhancement...
December 9, 2016: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/27930653/characterisation-of-development-and-electrophysiological-mechanisms-underlying-rhythmicity-of-the-avian-lymph-heart
#13
Sajjida Jaffer, Petr Valasek, Graham Luke, Munirah Batarfi, Benjamin Jason Whalley, Ketan Patel
Despite significant advances in tissue engineering such as the use of scaffolds, bioreactors and pluripotent stem cells, effective cardiac tissue engineering for therapeutic purposes has remained a largely intractable challenge. For this area to capitalise on such advances, a novel approach may be to unravel the physiological mechanisms underlying the development of tissues that exhibit rhythmic contraction yet do not originate from the cardiac lineage. Considerable attention has been focused on the physiology of the avian lymph heart, a discrete organ with skeletal muscle origins yet which displays pacemaker properties normally only found in the heart...
2016: PloS One
https://www.readbyqxmd.com/read/27927625/sympathetic-responsiveness-is-not-increased-in-women-with-a-history-of-hypertensive-pregnancy
#14
Sushant M Ranadive, Ronee E Harvey, Brian D Lahr, Virginia M Miller, Michael J Joyner, Jill N Barnes
Hypertensive pregnancy (HTNP) is a risk factor for future cardiovascular disease. Exaggerated cardiovascular responses to physical stress are also considered an independent marker of cardiovascular disease risk. However, there are limited data regarding the blood pressure (BP) responses to acute stress in women, who have a history of HTNP. Hence, the aim of the study is to compare BP responses to a physical stress in postmenopausal women with a history of HTNP to age- and parity-matched women with a history of normotensive pregnancy (NP)...
January 1, 2017: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
https://www.readbyqxmd.com/read/27914945/effects-of-zacopride-a-moderate-ik1-channel-agonist-on-triggered-arrhythmia-and-contractility-in-human-ventricular-myocardium
#15
Mohammad T Elnakish, Benjamin D Canan, Ahmet Kilic, Peter J Mohler, Paul M L Janssen
Ventricular tachycardia is the leading cause of sudden arrhythmic death in the U.S. Recently, the moderate IK1 channel activator, zacopride, was shown to suppress triggered ventricular tachycardia in rats. Nonetheless, concerns were raised about the possibility of pro-arrhythmic activity after IK1 channel stimulation based on the promising anti-arrhythmic strategy of IK1 blockade in other animal models. Therefore, the goal of the current study was to investigate the ex-vivo effects of zacopride on triggered arrhythmia and contractility in ventricular human myocardium in order to validate data that was solely obtained from animal models...
January 2017: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
https://www.readbyqxmd.com/read/27907103/tbx20-is-an-essential-regulator-of-embryonic-heart-growth-in-zebrafish
#16
Steffen Just, Linda Raphel, Ina M Berger, Anja Bühler, Mirjam Keßler, Wolfgang Rottbauer
The molecular mechanisms that regulate cardiomyocyte proliferation during embryonic heart growth are not completely deciphered yet. In a forward genetic N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we identified the recessive embryonic-lethal zebrafish mutant line weiches herz (whz). Homozygous mutant whz embryos display impaired heart growth due to diminished embryonic cardiomyocyte proliferation resulting in cardiac hypoplasia and weak cardiac contraction. By positional cloning, we found in whz mutant zebrafish a missense mutation within the T-box 20 (Tbx20) transcription factor gene leading to destabilization of Tbx20 protein...
2016: PloS One
https://www.readbyqxmd.com/read/27906129/the-evolutionary-origin-of-bilaterian-smooth-and-striated-myocytes
#17
Thibaut Brunet, Antje Hl Fischer, Patrick Rh Steinmetz, Antonella Lauri, Paola Bertucci, Detlev Arendt
The dichotomy between smooth and striated myocytes is fundamental for bilaterian musculature, but its evolutionary origin is unsolved. In particular, interrelationships of visceral smooth muscles remain unclear. Absent in fly and nematode, they have not yet been characterized molecularly outside vertebrates. Here, we characterize expression profile, ultrastructure, contractility and innervation of the musculature in the marine annelid Platynereis dumerilii and identify smooth muscles around the midgut, hindgut and heart that resemble their vertebrate counterparts in molecular fingerprint, contraction speed and nervous control...
December 1, 2016: ELife
https://www.readbyqxmd.com/read/27888388/cardiac-bin1-cbin1-is-a-regulator-of-cardiac-contractile-function-and-an-emerging-biomarker-of-heart-muscle-health
#18
REVIEW
Kang Zhou, Tingting Hong
In recent decades, a cardiomyocyte membrane scaffolding protein bridging integrator 1 (BIN1) has emerged as a critical multifunctional regulator of transverse-tubule (t-tubule) function and calcium signaling in cardiomyocytes. Encoded by a single gene with 20 exons that are alternatively spliced, more than ten BIN1 protein isoforms are expressed with tissue and disease specificity. The recently discovered cardiac alternatively spliced isoform BIN1 (cBIN1 or BIN1+13+17) plays a crucial role in organizing membrane microfolds within cardiac t-tubules...
November 23, 2016: Science China. Life Sciences
https://www.readbyqxmd.com/read/27886226/functional-improvement-and-regression-of-medial-hypertrophy-in-the-remodeled-pulmonary-artery-after-correction-of-systemic-left-to-right-shunt
#19
Chih-Hsin Hsu, Jun-Neng Roan, Jyh-Hong Chen, Chen-Fuh Lam
The presence of systemic left-to-right shunt and increased pulmonary blood flow can result in right heart failure and pulmonary arteriopathy. Correction of left-to-right shunt has been shown to improve cardiac function and physical performance. However, the cardiopulmonary remodeling processes following cessation of left-to-right shunt have yet to be reported. In this experimental study, excessive pulmonary flow was restored through ligation of the aortocaval fistula in rats with flow-induced pulmonary hypertension...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27884701/cardiac-inositol-1-4-5-trisphosphate-receptors
#20
REVIEW
M Iveth Garcia, Darren Boehning
Calcium is a second messenger that regulates almost all cellular functions. In cardiomyocytes, calcium plays an integral role in many functions including muscle contraction, gene expression, and cell death. Inositol 1,4,5-trisphosphate receptors (IP3Rs) are a family of calcium channels that are ubiquitously expressed in all tissues. In the heart, IP3Rs have been associated with regulation of cardiomyocyte function in response to a variety of neurohormonal agonists, including those implicated in cardiac disease...
November 22, 2016: Biochimica et Biophysica Acta
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