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https://www.readbyqxmd.com/read/28229413/cardiac-progenitor-cell-extraction-from-human-auricles
#1
Paolo Di Nardo, Francesca Pagliari
For many years, myocardial tissue has been considered terminally differentiated and, thus, incapable of regenerating. Recent studies have shown, instead, that cardiomyocytes, at least in part, are slowly substituted by new cells originating by precursor cells mostly embedded into the heart apex and in the atria. We have shown that an elective region of progenitor cell embedding is represented by the auricles, non-contractile atria appendages that can be easily sampled without harming the patient. The protocol here reported describes how from auricles a population of multipotent, cardiogenic cells can be isolated, cultured, and differentiated...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28223472/overexpression-of-sarcoendoplasmic-reticulum-calcium-atpase-2a-promotes-cardiac-sympathetic-neurotransmission-via-abnormal-endoplasmic-reticulum-and-mitochondria-ca-2-regulation
#2
Julia Shanks, Neil Herring, Errin Johnson, Kun Liu, Dan Li, David J Paterson
Reduced cardiomyocyte excitation-contraction coupling and downregulation of the SERCA2a (sarcoendoplasmic reticulum calcium ATPase 2a) is associated with heart failure. This has led to viral transgene upregulation of SERCA2a in cardiomyocytes as a treatment. We hypothesized that SERCA2a gene therapy expressed under a similar promiscuous cytomegalovirus promoter could also affect the cardiac sympathetic neural axis and promote sympathoexcitation. Stellate neurons were isolated from 90 to 120 g male, Sprague-Dawley, Wistar Kyoto, and spontaneously hypertensive rats...
February 21, 2017: Hypertension
https://www.readbyqxmd.com/read/28219708/novel-technique-to-determine-the-pka-of-clonidine-at-prejunctional-%C3%AE-2-adrenoceptors-in-cardiac-and-vascular-sympathetic-transmission
#3
James A Angus, Pravin Rajasekaran, Christine E Wright
Analytical pharmacology draws heavily on the concept of equilibrium of agonist and silent antagonist concentrations competing at a specific receptor site. This condition breaks down in nerve transmission when transmitter release is inhibited by prejunctional α2-adrenoceptors activated by an agonist such as clonidine. We have developed a method that allows the agonist dissociation constant KA of clonidine to be determined in a robust isolated right atrial assay of mouse, rat and guinea pig. By applying low numbers of field pulses 1-4 to prevent autoinhibitory feedback, clonidine shifted the nerve pulse stimulation-tachycardia curves to the right...
February 17, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28217229/evaluation-of-the-characteristics-of-rotational-activation-at-high-dominant-frequency-and-complex-fractionated-atrial-electrogram-sites-during-atrial-fibrillation
#4
Koji Kumagai, Kentaro Minami, Daisuke Kutsuzawa, Shigeru Oshima
BACKGROUND: High-dominant frequency (DF) and continuous complex fractionated atrial electrogram (CFAE) sites as surrogates for localized sources maintaining atrial fibrillation (AF) are potential AF ablation targets. This study aimed to evaluate the characteristics of a rotational activation at high-DF and continuous CFAE sites in AF patients. METHODS: Thirty-two consecutive AF patients (5 paroxysmal and 27 non-paroxysmal) underwent ablation using the NavX system...
February 2017: Journal of Arrhythmia
https://www.readbyqxmd.com/read/28155995/sinus-node-dysfunction-and-atrial-fibrillation-a-reversible-phenomenon
#5
REVIEW
Larry R Jackson Ii, Bharath Rathakrishnan, Kristen Campbell, Kevin L Thomas, Jonathan P Piccini, Tristram Bahnson, Jonathan A Stiber, James P Daubert
BACKGROUND: Symptomatic sinus node dysfunction (SND) consists of a variety of manifestations including tachycardia-bradycardia syndrome. Atrial fibrillation (AF) is commonly associated with SND, which complicates the management of both conditions. This paper reviews the epidemiology, pathophysiology, and clinical trial data investigating therapeutic approaches for treatment of patients with both SND and AF. METHODS: The authors reviewed articles published in English describing the epidemiology, pathophysiology, and therapeutic approaches for patients with SND and AF...
February 3, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28133984/new-arylsparteine-derivatives-as-positive-inotropic-drugs
#6
Vito Boido, Marcella Ercoli, Michele Tonelli, Federica Novelli, Bruno Tasso, Fabio Sparatore, Elena Cichero, Paola Fossa, Paola Dorigo, Guglielmina Froldi
Positive inotropic agents are fundamental in the treatment of heart failure; however, their arrhythmogenic liability and the increased myocardial oxygen demand strongly limit their therapeutic utility. Pursuing our study on cardiovascular activities of lupin alkaloid derivatives, several 2-(4-substituted-phenyl)-2-dehydrosparteines and 2-(4-substituted-phenyl)sparteines were prepared and tested for inotropic and chronotropic activities on isolated guinea pig atria. Four compounds (6b, 6e, 7b, and 7f) exhibited significant inotropism that, at the higher concentrations, was followed by negative inotropism or toxicity...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
https://www.readbyqxmd.com/read/28123766/low-incidence-of-left-atrial-delayed-enhancement-with-mri-in-patients-with-af-a-single-centre-experience
#7
John P Bois, James Glockner, Phillip M Young, Thomas A Foley, Seth Sheldon, Darrell B Newman, Grace Lin, Douglas L Packer, Peter A Brady
BACKGROUND: Atrial fibrillation (AF) is the most common sustained atrial arrhythmia. One potential target for ablation is left atrial (LA) scar (LAS) regions that may be the substrate for re-entry within the atria, thereby sustaining AF. Identification of LAS through LA delayed gadolinium enhancement (LADE) with MRI has been proposed. OBJECTIVES: We sought to evaluate LADE in patients referred for catheter ablation of AF. METHODS: Prospective analysis was conducted of consecutive patients who underwent pulmonary vein antrum isolation (PVAI) ablation for AF at a single institution...
2017: Open Heart
https://www.readbyqxmd.com/read/28104073/af-ablation-guided-by-spatiotemporal-electrogram-dispersion%C3%A2-without-pulmonary-vein-isolation-a-wholly-patient-tailored-approach
#8
Julien Seitz, Clément Bars, Guillaume Théodore, Sylvain Beurtheret, Nicolas Lellouche, Michel Bremondy, Ange Ferracci, Jacques Faure, Guillaume Penaranda, Masatoshi Yamazaki, Uma Mahesh R Avula, Laurence Curel, Sabrina Siame, Omer Berenfeld, André Pisapia, Jérôme Kalifa
BACKGROUND: The use of intracardiac electrograms to guide atrial fibrillation (AF) ablation has yielded conflicting results. OBJECTIVES: The authors evaluated the usefulness of spatiotemporal dispersion, a visually recognizable electric footprint of AF drivers, for the ablation of all forms of AF. METHODS: The authors prospectively enrolled 105 patients admitted for AF ablation. AF was sequentially mapped in both atria with a 20-pole PentaRay catheter...
January 24, 2017: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/28100216/antispasmodic-bronchodilator-vasorelaxant-and-cardiosuppressant-effects-of-buxus-papillosa
#9
Arif-Ullah Khan, Shamsher Ali, Anwarul-Hassan Gilani, Manzoor Ahmed, Muhammad Iqbal Choudhary
BACKGROUND: The present research was carried out to investigate pharmacological properties of Buxus papillosa C.K. Schneid. (Buxaceae). METHODS: Buxus papillosa extracts of leaves (BpL), stem (BpS), roots (BpR) and BpL fractions: hexane (BpL-H), aqueous (BpL-A) also plant constituent, cyclomicrobuxine effect were studied in jejunum, atria, aorta and tracheal preparations from rabbit and guine-peg. RESULTS: Ca(++) antagonistic effect of BpS, BpR, BpL-H, BpL-A and cyclomicrobuxine were conclusively suggested, when spontaneous contractions of rabbit jejunal preparation was relaxed along with subsequent relaxation of potassium chloride (80 mM) induced contractions...
January 18, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28091410/molecular-mechanisms-of-increased-heart-rate-in-shenxianshengmai-treated-bradycardia-rabbits
#10
Zhou-Ying Liu, Jian Huang, Na-Na Liu, Min Zheng, Tao Zhao, Bu-Chang Zhao, Yi-Min Wang, Jie-Lin Pu
BACKGROUND: The molecular mechanisms of Shenxianshengmai (SXSM), a traditional Chinese medicine, on bradycardia have been incompletely understood. The study tried to investigate the gene expression profile and proteomics of bradycardia rabbits' hearts after SXSM treatment. METHODS: Twenty-four adult rabbits were randomly assigned in four groups: sham, model, model plus SXSM treatment, and sham plus SXSM treatment groups. Heart rate was recorded in all rabbits. Then, total RNA of atria and proteins of ventricle were isolated and quantified, respectively...
2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28059795/evidence-of-a-cardiovascular-function-for-microtubule-associated-protein-tau
#11
Ashenafi H Betrie, Scott Ayton, Ashley I Bush, James A Angus, Peng Lei, Christine E Wright
Aggregation of tau protein into intracellular deposits is a pathognomonic feature of tauopathies such as Alzheimer's disease (AD) and lowering tau is a prominent therapeutic strategy under development. However, the physiological function of tau protein is not well known, particularly in the periphery. Lowering tau protein risks disrupting its physiological role leading to unwanted effects. In this study, the presence of tau protein in cardiac tissue is confirmed and the functional role in the cardiovascular system and the consequences of its loss were explored...
December 3, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28011828/changes-in-p-wave-morphology-after-pulmonary-vein-isolation-insights-from-computer-simulations
#12
Mirabeau Saha, Giulio Conte, Maria Luce Caputo, François Regoli, Rolf Krause, Angelo Auricchio, Vincent Jacquemet
AIMS: Apparently conflicting clinical measurements of P-wave duration (PWD) pre- vs. post-ablation have been reported. To assist the interpretation of these clinical data, we used a computer model of the atria and torso to simulate P waves before and after pulmonary vein (PV) isolation. METHODS AND RESULTS: Twenty ablation patterns were designed (segmental or ipsilateral ablation; five distances to PV sleeves; addition of a roof line or not). Possible PV reconnections were introduced as gaps in the ablation lines...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/27875722/progenitor-cells-from-atria-ventricle-and-peripheral-blood-of-the-same-patients-exhibit-functional-differences-associated-with-cardiac-repair
#13
Parul Dixit, Hayden Donnelly, Midori Edamatsu, Ivor Galvin, Richard Bunton, Rajesh Katare
AIM: Deciding the best cell type for cardiac regeneration remains a big challenge. No studies have directly compared the functional efficacy of cardiac progenitor cells (CPCs) with extra-cardiac stem cells isolated from the same patient. METHODS AND RESULTS: We compared the functional characteristics of endothelial progenitor cells (EPCs), right atrial (RAA) CPCs and left ventricular (LV) CPCs isolated from the same patients (n=14). Within the same heart, RAA and LV CPCs exhibited marked differences in surface marker expression, with RAA CPCs exhibiting better expansion potential and migration properties...
February 1, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/27863381/probucol-prevents-atrial-ion-channel-remodeling-in-an-alloxan-induced-diabetes-rabbit-model
#14
Huaying Fu, Guangping Li, Changle Liu, Jian Li, Lijun Cheng, Wansong Yang, Gary Tse, Jichao Zhao, Tong Liu
Diabetes mellitus (DM) increases the risk of developing atrial fibrillation (AF), but the molecular mechanisms of diabetes-induced atrial remodeling processes have not been fully characterized. The aim of this study was to examine the mechanisms underlying atrial ion channel remodeling in alloxan-induced diabetes model in rabbits. A total of 40 Japanese rabbits were randomly assigned to a control group (C), alloxan-induced diabetic group (DM), probucol-treated control group (Control-P), and probucol-treated diabetic group (DM-P)...
November 14, 2016: Oncotarget
https://www.readbyqxmd.com/read/27773652/refractoriness-in-human-atria-time-and-voltage-dependence-of-sodium-channel-availability
#15
Lasse Skibsbye, Thomas Jespersen, Torsten Christ, Mary M Maleckar, Jonas van den Brink, Pasi Tavi, Jussi T Koivumäki
BACKGROUND: Refractoriness of cardiac cells limits maximum frequency of electrical activity and protects the heart from tonic contractions. Short refractory periods support major arrhythmogenic substrates and augmentation of refractoriness is therefore seen as a main mechanism of antiarrhythmic drugs. Cardiomyocyte excitability depends on availability of sodium channels, which involves both time- and voltage-dependent recovery from inactivation. This study therefore aims to characterise how sodium channel inactivation affects refractoriness in human atria...
December 2016: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/27706179/noninvasive-imaging-of-human-atrial-activation-during-atrial-flutter-and-normal-rhythm-from-body-surface-potential-maps
#16
Zhaoye Zhou, Qi Jin, Long Yu, Liqun Wu, Bin He
BACKGROUND: Knowledge of atrial electrophysiological properties is crucial for clinical intervention of atrial arrhythmias and the investigation of the underlying mechanism. This study aims to evaluate the feasibility of a novel noninvasive cardiac electrical imaging technique in imaging bi-atrial activation sequences from body surface potential maps (BSPMs). METHODS: The study includes 7 subjects, with 3 atrial flutter patients, and 4 healthy subjects with normal atrial activations...
2016: PloS One
https://www.readbyqxmd.com/read/27660028/angiotensin-1-5-an-active-mediator-of-renin-angiotensin-system-stimulates-anp-secretion-via-mas-receptor
#17
Lamei Yu, Kuichang Yuan, Hoang Thi Ai Phuong, Byung Mun Park, Suhn Hee Kim
Angiotensin-(1-5) [Ang-(1-5)], which is a metabolite of Angiotensin-(1-7) [Ang-(1-7)] catalyzed by angiotensin-converting enzyme (ACE), is a pentapeptide of the renin-angiotensin system (RAS). It has been reported that Ang-(1-7) and Ang-(1-9) stimulate the secretion of atrial natriuretic peptide (ANP) via Mas receptor (Mas R) and Ang II type 2 receptor (AT2R), respectively. However, it still remains unknown whether Ang-(1-5) has a similar function to Ang-(1-7). We investigated the effect of Ang-(1-5) on ANP secretion and to define its signaling pathway using isolated perfused beating rat atria...
December 2016: Peptides
https://www.readbyqxmd.com/read/27609676/ganglion-plexus-ablation-in-advanced%C3%A2-atrial-fibrillation-the-afact-study
#18
Antoine H G Driessen, Wouter R Berger, Sébastien P J Krul, Nicoline W E van den Berg, Jolien Neefs, Femke R Piersma, Dean R P P Chan Pin Yin, Jonas S S G de Jong, WimJan P van Boven, Joris R de Groot
BACKGROUND: Patients with long duration of atrial fibrillation (AF), enlarged atria, or failed catheter ablation have advanced AF and may require more extensive treatment than pulmonary vein isolation. OBJECTIVES: The aim of this study was to investigate the efficacy and safety of additional ganglion plexus (GP) ablation in patients undergoing thoracoscopic AF surgery. METHODS: Patients with paroxysmal AF underwent pulmonary vein isolation...
September 13, 2016: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/27525575/cardiac-n-methyl-d-aspartate-receptors-as-a-pharmacological-target
#19
Asya Makhro, Qinghai Tian, Lars Kaestner, Dmitry Kosenkov, Giuseppe Faggian, Max Gassmann, Colin Schwarzwald, Anna Bogdanova
This study focuses on characterization of the cardiac N-methyl D-aspartate receptors (NMDARs) as a target for endogenous and synthetic agonists and antagonists. Using isolated perfused rat hearts, we have shown that intracoronary administration of the NMDAR agonists and antagonists has a pronounced effect on autonomous heart function. Perfusion of rat hearts with autologous blood supplemented with NMDAR agonists was associated with induction of tachycardia, sinus arrhythmia and ischemia occurring within physiological plasma concentration range for glutamate and glycine...
August 10, 2016: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/27496871/c-type-natriuretic-peptide-and-natriuretic-peptide-receptor-b-signalling-inhibits-cardiac-sympathetic-neurotransmission-and-autonomic-function
#20
Jens Buttgereit, Julia Shanks, Dan Li, Guoliang Hao, Arvinder Athwal, Thomas H Langenickel, Hannah Wright, Andrey C da Costa Goncalves, Jan Monti, Ralph Plehm, Elena Popova, Fatimunnisa Qadri, Irina Lapidus, Brent Ryan, Cemil Özcelik, David J Paterson, Michael Bader, Neil Herring
AIMS: B-type natriuretic peptide (BNP)-natriuretic peptide receptor A (NPR-A) receptor signalling inhibits cardiac sympathetic neurotransmission, although C-type natriuretic peptide (CNP) is the predominant neuropeptide of the nervous system with expression in the heart and vasculature. We hypothesized that CNP acts similarly to BNP, and that transgenic rats (TGRs) with neuron-specific overexpression of a dominant negative NPR-B receptor would develop heightened sympathetic drive. METHODS AND RESULTS: Mean arterial pressure and heart rate (HR) were significantly (P < 0...
December 2016: Cardiovascular Research
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