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https://www.readbyqxmd.com/read/28096338/mitochondrial-fusion-dynamics-is-robust-in-the-heart-and-depends-on-calcium-oscillations-and-contractile-activity
#1
Verónica Eisner, Ryan R Cupo, Erhe Gao, György Csordás, William S Slovinsky, Melanie Paillard, Lan Cheng, Jessica Ibetti, S R Wayne Chen, J Kurt Chuprun, Jan B Hoek, Walter J Koch, György Hajnóczky
Mitochondrial fusion is thought to be important for supporting cardiac contractility, but is hardly detectable in cultured cardiomyocytes and is difficult to directly evaluate in the heart. We overcame this obstacle through in vivo adenoviral transduction with matrix-targeted photoactivatable GFP and confocal microscopy. Imaging in whole rat hearts indicated mitochondrial network formation and fusion activity in ventricular cardiomyocytes. Promptly after isolation, cardiomyocytes showed extensive mitochondrial connectivity and fusion, which decayed in culture (at 24-48 h)...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28096168/sk-channel-enhancers-attenuate-ca2-dependent-arrhythmia-in-hypertrophic-hearts-by-regulating-mito-ros-dependent-oxidation-and-activity-of-ryr
#2
Tae Yun Kim, Radmila Terentyeva, Karim H F Roder, Weiyan Li, Man Liu, Ian Greener, Shanna Hamilton, Iuliia Polina, Kevin R Murphy, Richard T Clements, Samuel C Dudley, Gideon Koren, Bum-Rak Choi, Dmitry Terentyev
AIM: s: Plasmamembrane small conductance Ca<su2+p>-activated K<su+ p > (SK) channels were implicated in ventricular arrhythmias in infarcted and failing hearts. Recently, SK channels were detected in the mitochondria inner membrane (mSK), and their activation protected from acute ischemia-reperfusion injury by reducing intracellular levels of reactive oxygen species (ROS). We hypothesized that mSK play an important role in regulating mitochondrial function in chronic cardiac diseases...
January 17, 2017: Cardiovascular Research
https://www.readbyqxmd.com/read/28094777/high-resolution-structural-evidence-suggests-the-sarcoplasmic-reticulum-forms-microdomains-with-acidic-stores-lysosomes-in-the-heart
#3
Daniel Aston, Rebecca A Capel, Kerrie L Ford, Helen C Christian, Gary R Mirams, Eva A Rog-Zielinska, Peter Kohl, Antony Galione, Rebecca A B Burton, Derek A Terrar
Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) stimulates calcium release from acidic stores such as lysosomes and is a highly potent calcium-mobilising second messenger. NAADP plays an important role in calcium signalling in the heart under basal conditions and following β-adrenergic stress. Nevertheless, the spatial interaction of acidic stores with other parts of the calcium signalling apparatus in cardiac myocytes is unknown. We present evidence that lysosomes are intimately associated with the sarcoplasmic reticulum (SR) in ventricular myocytes; a median separation of 20 nm in 2D electron microscopy and 3...
January 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28089575/association-of-uterine-fibroids-and-pregnancy-outcomes-after-ovarian-stimulation-intrauterine-insemination-for-unexplained-infertility
#4
Aaron K Styer, Susan Jin, Dan Liu, Baisong Wang, Alex J Polotsky, Mindy S Christianson, Wendy Vitek, Lawrence Engmann, Karl Hansen, Robert Wild, Richard S Legro, Christos Coutifaris, Ruben Alvero, Randal D Robinson, Peter Casson, Gregory M Christman, Alicia Christy, Michael P Diamond, Esther Eisenberg, Heping Zhang, Nanette Santoro
OBJECTIVE: To investigate the association of non-cavity-distorting uterine fibroids and pregnancy outcomes after ovarian stimulation-intrauterine insemination (OS-IUI) in couples with unexplained infertility. DESIGN: Secondary analysis from a prospective, randomized, multicenter clinical trial investigating fertility outcomes after OS-IUI. SETTING: Reproductive Medicine Network clinical sites. PATIENT(S): Nine hundred couples with unexplained infertility who participated in the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) clinical trial...
January 12, 2017: Fertility and Sterility
https://www.readbyqxmd.com/read/28088331/eicosapentaenoic-acid-ameliorates-palmitate-induced-lipotoxicity-via-the-amp-kinase-dynamin-related-protein-1-signaling-pathway-in-differentiated-h9c2-myocytes
#5
Atsushi Sakamoto, Masao Saotome, Prottoy Hasan, Terumori Satoh, Hayato Ohtani, Tsuyoshi Urushida, Hideki Katoh, Hiroshi Satoh, Hideharu Hayashi
BACKGROUND: Emerging evidence suggested the preferable effects of eicosapentaenoic acid (EPA; n-3 polyunsaturated fatty acid) against cardiac lipotoxicity, which worsens cardiac function by means of excessive serum free fatty acids due to chronic adrenergic stimulation under heart failure. Nonetheless, the precise molecular mechanisms remain elusive. In this study, we focused on dynamin-related protein-1 (Drp1) as a possible modulator of the EPA-mediated cardiac protection against cardiac lipotoxicity, and investigated the causal relation between AMP-activated protein kinase (AMPK) and Drp1...
January 11, 2017: Experimental Cell Research
https://www.readbyqxmd.com/read/28088261/parquetina-nigrescens-leaves-chemical-profile-and-influence-on-the-physical-and-biochemical-indices-of-sexual-activity-of-male-wistar-rats
#6
Omowumi Titilola Kayode, Musa Toyin Yakubu
OBJECTIVE: The leaves of Parquetina nigrescens have been claimed in folk medicine to be useful for managing sexual dysfunction, but there is inadequate scientific evidence for this claim. This investigation was conducted to assess the effects of aqueous leaf extract of Parquetina nigrescens (AEPN) in rats induced with sexual dysfunction. METHODS: Male rats were allocated into various groups after being induced into sexual dysfunction with paroxetine hydrochloride...
January 2017: Journal of Integrative Medicine
https://www.readbyqxmd.com/read/28087519/sympathetic-modulation-of-electrical-activation-in-normal-and-infarcted-myocardium-implications-for-arrhythmogenesis
#7
Olujimi A Ajijola, Robert L Lux, Anadjeet Khahera, OhJin Kwon, Eric Aliotta, Daniel Ennis, Michael C Fishbein, Jeffrey Laurence Ardell, Kalyanam Shivkumar
: Background The influence of cardiac sympathetic innervation on electrical activation in normal and chronically infarcted ventricular myocardium is not understood. Methods and Results Yorkshire pigs with normal hearts (NL, n=12) or anterior myocardial infarction (MI, n=9) underwent high-resolution mapping of the anteroapical left ventricle, at baseline, and during left and right stellate ganglion stimulation (LSGS & RSGS, respectively). Conduction velocity (CV), activation times (AT), & directionality of propagation were measured...
January 13, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28080973/changes-in-interoceptive-processes-following-brain-stimulation
#8
Olga Pollatos, Beate M Herbert, Sandra Mai, Thomas Kammer
The processing and perception of individual internal bodily signals (interoception) has been differentiated to comprise different levels and processes involved. The so-called heartbeat-evoked potential (HEP) offers an additional possibility to examine automatic processing of cardiac signals. Knowledge on neural structures potentially supporting different facets of interoception is still sparse. One way to get insights into neuroanatomical function is to manipulate the activity of different brain structures...
November 19, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28080972/towards-a-psychophysics-of-interoceptive-processes-the-measurement-of-heartbeat-detection
#9
REVIEW
Jasper Brener, Christopher Ring
It is difficult to collect objective evidence of interoception. Unlike exteroception, the effective stimuli for interoception are often unknown, and even when identifiable, they are difficult to control experimentally. Furthermore, direct stimulation of the interoceptors is seldom appropriate in human experimentation. Hence, non-invasive behavioural measures of accuracy in heartbeat detection have frequently been adopted to index interoceptive sensitivity. However, there has been little standardization and the two most popular methods for assessing heartbeat detection, heartbeat tracking and two alternative forced choice methods, appear to be biased and of questionable validity...
November 19, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28079427/effect-of-functional-electrical-stimulation-on-cardiovascular-outcomes-in-patients-with-chronic-heart-failure
#10
Nikolaos Pe Kadoglou, Christina Mandila, Apostolos Karavidas, Dimitrios Farmakis, Vasiliki Matzaraki, Christos Varounis, Sofia Arapi, Anastasia Perpinia, John Parissis
Background/design Functional electrical stimulation of lower limb muscles is an alternative method of training in patients with chronic heart failure (CHF). Although it improves exercise capacity in CHF, we performed a randomised, placebo-controlled study to investigate its effects on long-term clinical outcomes. Methods We randomly assigned 120 patients, aged 71 ± 8 years, with stable CHF (New York Heart Association (NYHA) class II/III (63%/37%), mean left ventricular ejection fraction 28 ± 5%), to either a 6-week functional electrical stimulation training programme or placebo...
January 1, 2017: European Journal of Preventive Cardiology
https://www.readbyqxmd.com/read/28079228/attenuated-recovery-of-contractile-function-in-aging-hearts-following-global-ischemia-reperfusion-role-of-extracellular-hsp27-and-tlr4
#11
Lihua Ao, Yufeng Zhai, Chunhua Jin, Joseph C Cleveland, David A Fullerton, Xianzhong Meng
BACKGROUND: While cardiac functional recovery is attenuated in the elderly following cardiac surgery with obligatory global myocardial ischemia/reperfusion (I/R), the underlying mechanism remains incompletely understood. We observed previously that human and mouse myocardium releases heat shock protein (HSP) 27 during global I/R. Extracellular HSP27 induces myocardial inflammatory response and plays a role in post-ischemic cardiac dysfunction in adult mouse hearts. OBJECTIVE: This study was to determine the role of extracellular HSP27 and Toll-like receptor 4 (TLR4) in the attenuated functional recovery in aging mouse hearts following global I/R...
December 19, 2016: Molecular Medicine
https://www.readbyqxmd.com/read/28077443/single-dose-intracardiac-injection-of-pro-regenerative-micrornas-improves-cardiac-function-after-myocardial-infarction
#12
Pierluigi Lesizza, Giulia Prosdocimo, Valentina Martinelli, Gianfranco Sinagra, Serena Zacchigna, Mauro Giacca
RATIONALE: Recent evidence indicates that a few human microRNAs (miRNAs), in particular hsa-miR-199a-3p and hsa-miR-590-3p, stimulate proliferation of cardiomyocytes and, once expressed in the mouse heart using viral vectors, induce cardiac regeneration after myocardial infarction. Viral vectors, however, are not devoid of safety issues and, more notably, drive expression of the encoded miRNAs for indefinite periods of time, which might not be desirable in light of human therapeutic application...
January 11, 2017: Circulation Research
https://www.readbyqxmd.com/read/28073805/sheet-like-remodeling-of-the-transverse-tubular-system-in-human-heart-failure-impairs-excitation-contraction-coupling-and-functional-recovery-by-mechanical-unloading
#13
Thomas Seidel, Sutip Navankasattusas, Azmi A Ahmad, Nikolaos A Diakos, Weining D Xu, Martin Tristani-Firouzi, Michael Bonios, Iosif Taleb, Dean Y Li, Craig H Selzman, Stavros G Drakos, Frank B Sachse
BACKGROUND: -Cardiac recovery in response to mechanical unloading by left ventricular assist devices (LVADs) has been demonstrated in subgroups of chronic heart failure (HF) patients. Hallmarks of HF are depletion and disorganization of the transverse tubular system (t-system) in cardiomyocytes. Here, we investigated remodeling of the t-system in human end-stage HF and its role in cardiac recovery. METHODS: -Left ventricular biopsies were obtained from 5 donors (CTRL) and 26 chronic HF patients undergoing implantation of LVADs...
January 10, 2017: Circulation
https://www.readbyqxmd.com/read/28072755/strategies-for-an-expanded-use-of-kidneys-from-elderly-donors
#14
María José Pérez-Sáez, Nuria Montero, Dolores Redondo-Pachón, Marta Crespo, Julio Pascual
The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor (ECD) or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index (KDPI) policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols...
January 9, 2017: Transplantation
https://www.readbyqxmd.com/read/28072471/the-negative-chronotropic-effect-in-rat-heart-stimulated-by-ultrasonic-pulses-role-of-sex-and-age
#15
Olivia C Coiado, William D O'Brien
OBJECTIVES: The goal of this study is to investigate the role of sex and age of the negative chronotropic effect after exposure of 3.5-MHz pulsed ultrasound (US) to the rat heart. METHODS: Forty F344 rats were exposed transthoracically to ultrasonic pulses at a duty factor of approximately 1.0% at 2.0-MPa peak rarefactional pressure amplitude. The transthoracic ultrasonic bursts were delivered consecutively in five 10-s intervals, that is, 10 s of 6-Hz pulse repetition frequency (PRF), 10 s of 5-Hz PRF, 10 s of 4-Hz PRF, 10 s of 5-Hz PRF, and 10 s of 6-Hz, for a 50-s total exposure duration...
January 10, 2017: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/28070060/the-brugada-syndrome%C3%A3-from-gene-to-therapy
#16
Antonio Curcio, Giuseppe Santarpia, Ciro Indolfi
It is almost a quarter of century that a pioneering work of 2 researchers named Brugada brought the entire scientific community to understanding the molecular, clinical, and electrophysiological aspects of a distinctive syndrome. It affects mainly young adults with syncope and/or sudden cardiac death caused by polymorphic ventricular tachycardia or ventricular fibrillation in the absence of any sign of cardiac degeneration or alteration. Although the involvement of the epicardial layer of the right ventricular outflow tract, and the requirement of pharmacologic challenge for unveiling concealed forms, have been fully characterized, many areas of uncertainties remain to be elucidated, such as the unpredictable usefulness of programmed ventricular stimulation, the role of radiofrequency catheter ablation for reducing ST-segment elevation, and the value of risk stratification in patients diagnosed with upper displacement of right precordial leads...
January 7, 2017: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/28069985/high-throughput-imaging-of-cardiac-microtissues-for-the-assessment-of-cardiac-contraction-during-drug-discovery
#17
Amy Pointon, James Pilling, Thierry Dorval, Yinhai Wang, Caroline Archer, Christopher Pollard
Cardiotoxicity is a common cause of attrition in preclinical and clinical drug development. Current in vitro approaches have two main limitations, they either are limited to low throughput methods not amendable to drug discovery or lack the physiological responses to allow an integrated risk assessment. A human 3D cardiac microtissue containing human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs), cardiac endothelial cells and cardiac fibroblast were used to assess their suitability to detect drug induced changes in cardiomyocyte contraction...
November 15, 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
https://www.readbyqxmd.com/read/28067978/imaging-left-ventricular-mechanical-activation-in-heart-failure-patients-using-cine-dense-mri-validation-and-implications-for-cardiac-resynchronization-therapy
#18
Daniel A Auger, Kenneth C Bilchick, Jorge A Gonzalez, Sophia X Cui, Jeffrey W Holmes, Christopher M Kramer, Michael Salerno, Frederick H Epstein
PURPOSE: To image late mechanical activation and identify effective left-ventricular (LV) pacing sites for cardiac resynchronization therapy (CRT). There is variability in defining mechanical activation time, with some studies using the time to peak strain (TPS) and some using the time to the onset of circumferential shortening (TOS). We developed improved methods for imaging mechanical activation and evaluated them in heart failure (HF) patients undergoing CRT. MATERIALS AND METHODS: We applied active contours to cine displacement encoding with stimulated echoes (DENSE) strain images to detect TOS...
January 9, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28066827/optimized-left-ventricular-endocardial-stimulation%C3%A2-is-superior-to-optimized-epicardial%C3%A2-stimulation-in-ischemic-patients-with%C3%A2-poor-response-to-cardiac-resynchronization%C3%A2-therapy-a%C3%A2-combined-magnetic-resonance-imaging-electroanatomic%C3%A2-contact-mapping-and-hemodynamic
#19
Jonathan M Behar, Tom Jackson, Eoin Hyde, Simon Claridge, Jaswinder Gill, Julian Bostock, Manav Sohal, Bradley Porter, Mark O'Neill, Reza Razavi, Steve Niederer, Christopher Aldo Rinaldi
OBJECTIVES: The purpose of this study was to identify the optimal pacing site for the left ventricular (LV) lead in ischemic patients with poor response to cardiac resynchronization therapy (CRT). BACKGROUND: LV endocardial pacing may offer benefit over conventional CRT in ischemic patients. METHODS: We performed cardiac magnetic resonance, invasive electroanatomic mapping (EAM), and measured the acute hemodynamic response (AHR) in patients with existing CRT systems...
December 2016: JACC. Clinical Electrophysiology
https://www.readbyqxmd.com/read/28065908/ticagrelor-but-not-clopidogrel-active-metabolite-displays-antithrombotic-properties-in-the-left-atrial-endocardium
#20
Martin F Reiner, Alexander Breitenstein, Erik W Holy, Martina Glanzmann, Heidi Amstalden, Simon F Stämpfli, Nicole R Bonetti, Volkmar Falk, Stephan Keller, Gianluigi Savarese, Stefano Benussi, Francesco Maisano, Thomas F Lüscher, Jürg H Beer, Jan Steffel, Giovanni G Camici
AIMS: Oral anticoagulation is considered standard therapy for stroke prevention in atrial fibrillation (AF). Endocardial activation triggers expression of pro-thrombotic mediators including tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1), and contributes to thrombus formation in the left atrial appendage (LAA) of AF patients. Recently, pleiotropic effects of specific P2Y12 receptor antagonists were demonstrated; however, whether these drugs possess antithrombotic effects on LAA endocardial cells currently remains unknown...
January 8, 2017: European Heart Journal
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