Synthesis and molecular and electronic structures of a series of Mo3CoSe4 cluster complexes with three different metal electron populations.

The synthesis, crystal structure, and magnetic properties of [Mo 3(CoCO)Se 4(dmpe) 3Cl 3] ( 1), [Mo 3(CoCl)Se 4(dmpe) 3Cl 3] ( 2), and [Mo 3(CoCl)Se 4(dmpe) 3Cl 3](TCNQ) ([ 2](TCNQ)) (dmpe = 1,2-bis(dimethylphosphanyl)ethane; TCNQ = 7,7,8,8-tetracyanoquinomethane) cubane-type complexes with 16, 15, and 14 metal electrons, respectively, are reported. These compounds complete the series of cobalt-containing Mo 3CoQ 4 (Q = S, Se) cubane-type complexes, which allows a complete analysis of the consequences of replacing the inner chalcogen and the metal electron count on the structural, magnetic, and electrochemical properties. The experimental evidence is theoretically supported and rationalized…

Evaluation of the Complexity of Myocardial Activation During Ventricular Fibrillation. An Experimental Study

A B S T R A C T Introduction and objectives: An experimental model is used to analyze the characteristics of ventricular fibrillation in situations of variable complexity, establishing relationships among the data produced by different methods for analyzing the arrhythmia. Methods: In 27 isolated rabbit heart preparations studied under the action of drugs (propranolol and KB-R7943) or physical procedures (stretching) that produce different degrees of change in the complexity of myocardial activation during ventricular fibrillation, use was made of spectral, morphological, and mapping techniques to process the recordings obtained with epicardial multielectrodes. Results: The complexity of ve…

Modifications in Ventricular Fibrillation and Capture Capacity Induced by a Linear Radiofrequency Lesion

[EN] Introduction and objectives: An analysis was made of the effects of a radiofrequency-induced linear lesion during ventricular fibrillation and the capacity to capture myocardium through high-frequency pacing. Methods: Using multiple epicardial electrodes, ventricular fibrillation was recorded in 22 isolated perfused rabbit hearts, analyzing the activation maps upon applying trains of stimuli at 3 different frequencies close to that of the arrhythmia: a) at baseline; b) after radio-frequency ablation to induce a lesion of the left ventricular free wall (length=10 [1] mm), and c) after lengthening the lesion (length=23 [2] mm). Results: Following lesion induction, the regularity of the r…

Changes in the Spectral Characteristics of Ventricular Fibrillation in Lesions Produced by Radiofrequency Ablation. An Experimental Study

INTRODUCTION AND OBJECTIVES Although electro- physiological databases contain information about changes in the time domain in lesions produced by radiofrequency ablation, very few data on changes in the frequency domain are available. The aim of this study was to investigate changes in the spectral characteristics of ventricular fibrillation in zones with radiofrequency lesions. METHODS Recordings of ventricular fibrillation were obtained in 11 isolated perfused rabbit heart preparations using a multiple epicardial electrode located on the left ventricular free wall. Spectral parameters derived by Fourier analysis before and after the creation of transmural radiofrequency lesions were compa…

Ranolazine induced modifications of ventricular fibrillation activation complexity under mechanical stretch

P267Myocardial electrophysiological effects mediated by KATP channels: controversial aspects about their involvement in the protection by chronic exercise

Prussian blue@MoS2 layer composites as highly efficient cathodes for sodium- and potassium-ion batteries

Prussian blue (PB) represents a simple, economical, and eco‐friendly system as cathode material for sodium‐ion batteries (SIBs). However, structural problems usually worsen its experimental performance thus motivating the search for alternative synthetic strategies and the formation of composites that compensate these deficiencies. Herein, a straightforward approach for the preparation of PB/MoS2‐based nanocomposites is presented. MoS2 provides a 2D active support for the homogeneous nucleation of porous PB nanocrystals, which feature superior surface areas than those obtained by other methodologies, giving rise to a compact PB shell covering the full flake. The nanocomposite exhibits an ex…

P1602Basic electrophysiological modifications induced by carvedilol in unstrectched and stretched ventricular myocardium

Abstract Background Acute regional ventricular stretch (ARVS) is a pathophysiologic event that may occur in certain situations, originating arrhythmogenic effects through the mechanoelectrical feedback. Mechanical effects of stretch originate calcium-related changes as sarcoplasmic recticulum Ca2+ overload that can trigger Ca2+ diastolic leaks (store-overload-induced Ca2+ release, SOICR), mediated by the cardiac ryanodine receptor (RyR2). SOICR seems to be implicated in the mechanisms underlying stretch-induced arrhythmias. Carvedilol can inhibit the overload of Ca2+ through blocking of beta-adrenergic receptors, and also suppress the release of Ca2+ induced by the SOICR. Purpose The aim of…

Development and Long-Term Follow-Up of an Experimental Model of Myocardial Infarction in Rabbits

Simple Summary Ischemic heart disease is one of the leading causes of death. A series of processes occur during acute myocardial infarction that contribute to the development of ventricular dysfunction, with subsequent heart failure and ventricular arrhythmias, which account for most episodes of sudden cardiac death in these patients. These complications are associated with the adverse cardiac remodeling that occurs during the healing process following an acute episode. The remodeling causes the appearance of a substrate that can trigger life-threatening arrhythmias, such as tachycardia and/or ventricular fibrillation. The development of experimental models for analyzing the basic mechanism…

Endurance training increases ventricular refractoriness and wavelength of the cardiac impulse without participation of parasympathetic postganglionic neurons. A study in isolated rabbit heart

Abstract Background Endurance physical training plays a protective role in against ventricular fibrillation (VF), but the exact underlying mechanisms are not completely understood. It is well-known that modifications in myocardial ventricular properties such as refractoriness, conduction velocity and wavelength are key in the initiation and maintenance of VF; furthermore, vagus nerve stimulation has prophylactic effects on malignant arrhythmias and VF. On the other hand, parasympathetic nervous system activity is increased in trained individuals, which in turn affects different ventricular electrophysiological properties. We hypothesized that physical training increases conduction velocity …

Bis[(trimethylsilyl)methyl]manganese: Structural Variations of Its Solvent-Free and TMEDA-, Pyridine-, and Dioxane-Complexed Forms

First synthesized in 1976 and recently taking on a new significance as a key precursor to heterobimetallic alkali-metal-manganese(II) complexes, bis[(trimethylsilyl)methyl] manganese has been structurally characterized by X-ray crystallography. It forms a polymeric chain structure of formula [{Mn(CH2SiMe3)(2)}(infinity)], 1, in which distorted tetrahedral, spiro Mn atoms are linked together via mu(2)-bonding alkyl ligands. The structure is notable for displaying two distinct categories of Mn-C bond lengths with a mean size differential of 0.225 angstrom and for being the first fully crystallographically characterized polymeric manganese(II) dialkyl compound. Magnetic measurements of 1 indic…

P314Modifications of atrial refractoriness produced in an experimental rabbit model of diet-induced metabolic syndrome

P3492Carvedilol and its analogue VK-II-86 attenuate stretch-induced manifestations of mechanoelectric feedback

Abstract Background Mechanical stretch modifies Ca2+ handling and myocardial electrophysiology, favoring arrhythmogenesis. The store-overload-induced Ca2+ release (SOICR) through the ryanodine receptor (RyR2) seems to be implicated in this deleterious effect. Carvedilol and its analogue VK-II-86 (which does not have significant beta-blocking effects) suppress SOCIR by directly reducing the open duration of the cardiac RyR2, and could modulate calcium-related changes produced by myocardial stretch. Purpose The aim of this study was to investigate, by the ventricular fibrillation (VF) spectral analysis, whether carvedilol and VK-II-86 prevents stretch-induced arrhythmogenic effects. Methods T…

Effect of chronic exercise on myocardial electrophysiological heterogeneity and stability. Role of intrinsic cholinergic neurons: A study in the isolated rabbit heart

[EN] A study has been made of the effect of chronic exercise on myocardial electrophysiological heterogeneity and stability, as well as of the role of cholinergic neurons in these changes. Determinations in hearts from untrained and trained rabbits on a treadmill were performed. The hearts were isolated and perfused. A pacing electrode and a recording multielectrode were located in the left ventricle. The parameters determined during induced VF, before and after atropine (1 mu M), were: fibrillatory cycle length (VV), ventricular functional refractory period (FRPVF), normalized energy (NE) of the fibrillatory signal and its coefficient of variation (CV), and electrical ventricular activatio…

Analysis of the Modifications in the Spectral and Morphologic Regularity during Ventricular Fibrillation Produced by Physical Exercise and the Use of Glibenclamide

Chronic physical exercise modifies cardiac activity improving response to malignant arrhythmia and, specifically, ventricular fibrillation (VF). Drug administration as glibenclamide, responsible for K + ATP channel blocking, is also generating a positive response against fibrillation.

Dominant frequency and complexity of electrical reentrant activation during ventricular fibrillation with releasing of NO after acute local stretching. A study in isolated rabbit heart

Analyzing the electrophysiological effects of local epicardial temperature in experimental studies with isolated hearts

As a result of their modulating effects upon myocardial electrophysiology, both hypo- and hyperthermia can be used to study the mechanisms that generate or sustain cardiac arrhythmias. The present study describes an original electrode developed with thick-film technology and capable of controlling regional temperature variations in the epicardium while simultaneously registering its electrical activity. In this way, it is possible to measure electrophysiological parameters of the heart at different temperatures. The results obtained with this device in a study with isolated and perfused rabbit hearts are reported. An exploration has been made of the effects of local temperature changes upon…

Association Between COL5a1, COL11a1, and COL11a2 Gene Variations and Rotator Cuff Tendinopathy in Young Athletes

Objective Tendinopathy is a prevalent condition in young athletes and in older nonathletic people. Recent tendinopathy research has shown a growing interest in the role played by genetic factors, basically genes involved in collagen synthesis and regulation, in view of collagen disorganization typically present in tendon pathologies. Design A case-control, genotype-phenotype association study. Setting La Ribera Hospital, Valencia, Spain. Participants A group of 137 young athletes (49 with rotator cuff tendon pathology and 88 healthy counterparts) who played upper-limb-loading sports were clinically and ultrasound (US) assessed for rotator cuff tendinopathy were included. Intervention Geneti…

CaMKII inhibition reduces electrical activation heterogeneities caused by mechanical stretch in the myocardium

Abstract Introduction Ca2+/calmodulin-dependant protein kinase II (CaMKII) activity in cardiomyocytes plays a crucial role in their contractility. Increased CaMKII signalling has been associated with mechanical stretch, often caused in the border zone of myocardial infarction. CaMKII upregulation causes a mishandling of intracellular calcium, a precursor of multiple pro-arrhythmic mechanisms, such as early afterdepolarisations. Purpose In this study, we aim to quantify the effects of KN-93 -a CaMKII inhibitor- on wave dynamics, in order to investigate its effectiveness as an anti-arrhythmic agent. Methods An isolated Langendorff model was constructed based on rabbit hearts (n=18) and poster…

Altered atrial restitution dynamics and refractoriness in metabolic syndrome due to up-regulation of potassium repolarizing currents increases susceptibility to atrial fibrillation

Abstract Background Metabolic alterations, such as Metabolic Syndrome (MS), describe an association of factors including diabetes, hypertension, obesity and dyslipidemia, linked to higher risk and prevalence of overall cardiovascular disease, arrhythmogenesis and sudden cardiac death. Obese and diabetic patients have shown an increased risk for developing atrial fibrillation (AF). However, underlying mechanisms are not understood. Purpose To study the effects of MS and obesity remodeling in atrial restitution dynamics, frequency-dependent adaptation, refractoriness and its potential susceptibility to AF. Methods Electrophysiological experimental data from High-fat (HF-O, standard rabbit cho…

Simultaneous atrial and ventricular restitution and fibrillation analyses using a low-cost scalable panoramic whole-heart optical mapping configuration for whole-heart imaging of translational models

Abstract Introduction Optical mapping (OM) is the primary method for imaging electrophysiologically relevant parameters from the outer surface of Langendorff-perfused hearts. However, current panoramic OM systems are financially challenging, require multiple sensors to map wide areas of the surface with overlapping regions and missing areas of interest due to the intrinsic shape of the heart. We proposed different panoramic configurations to dynamically characterize atrial and ventricular function during arrhythmia and, in presence of a coronary occlusion. Methods We devised both a multi-sensor and a single sensor system integrated with the perfusion circuit comprising sensor elements, a co…

WS2/MoS2 Heterostructures via Thermal Treatment of MoS2 Layers Electrostatically Functionalized with W3S4 Molecular Clusters

The preparation of 2D stacked layers that combine flakes of different nature, gives rise to countless number of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides WS2/MoS2, has awaken great interest due to its photovoltaic and photoelectrochemical properties. Solution as well as dry physical methods have been developed to optimize the synthesis of these heterostructures. Here a suspension of negatively charged MoS2 flakes is mixed with a methanolic solution of a cationic W3S…

Molecular conductors based on the mixed-valence polyoxometalates [SMo12O40]n- (n = 3 and 4) and the organic donors bis(ethylenedithio)tetrathiafulvalene and bis(ethylenedithio)tetraselenafulvalene.

The synthesis, crystal structure, and physical characterization of two new radical salts formed by the organic donors bis(ethylenedithio)tetrathiafulvalene (ET) and bis(ethylenediseleno)tetrathiafulvalene (BETS) and the Keggin polyoxometalate (POM) [SMo(12)O(40)](n-) are reported. The salts isolated are ET(8)[SMo(12)O(40)] x 10 H(2)O (1) (crystal data: (1) monoclinic, space group I2/m with a = 13.9300(10) A, b = 43.467(3) A, c = 13.9929(13) A, beta = 107.979(6) degrees, V = 8058.9(11) A(3), Z = 2) and BETS(8)[SMo(12)O(40)] x 10 H(2)O (2) (crystal data: monoclinic, space group I2/m with a = 14.0878(2) A, b = 44.1010(6) A, c = 14.0930(2) A, beta = 106.739(3) degrees, V = 8384.8 A(3), Z = 2). …

An Experimental Model of Diet-Induced Metabolic Syndrome in Rabbit: Methodological Considerations, Development, and Assessment

In recent years, obesity and metabolic syndrome (MetS) have become a growing problem for public health and clinical practice, given their increased prevalence due to the rise of sedentary lifestyles and unhealthy eating habits. Thanks to animal models, basic research can investigate the mechanisms underlying pathological processes such as MetS. Here, we describe the methods used to develop an experimental rabbit model of diet-induced MetS and its assessment. After a period of acclimation, animals are fed a high-fat (10% hydrogenated coconut oil and 5% lard), high-sucrose (15% sucrose dissolved in water) diet for 28 weeks. During this period, several experimental procedures were performed to…

Influencia del tipo de registro (unipolar o bipolar) en las características espectrales de los registros epicárdicos de la fibrilación ventricular. Estudio experimental

Introduction and objectives. The aim of this study was to examine the hypothesis that the recording mode (ie, unipolar or bipolar) affects the information obtained using spectral analysis techniques during ventricular fibrillation by carrying out an experiment using epicardial electrodes. Methods. Recordings of ventricular fibrillation were obtained in 29 isolated rabbit hearts using a multipleelectrode probe located on the left ventricular free wall. The parameter values obtained in the frequency domain (by Fourier analysis) using unipolar or bipolar electrodes, different interelectrode distances, and different orientations (ie, horizontal, vertical, or diagonal) were compared. Results. Ch…

Modificaciones de las características espectrales de la fibrilación ventricular en las lesiones producidas con radiofrecuencia. Estudio experimental

Introduccion y objetivos Aunque se dispone de informacion sobre las modificaciones en el dominio del tiempo de los registros electrofisiologicos en zonas lesionadas con radiofrecuencia, los datos disponibles en el dominio de la frecuencia son muy escasos. Se analizan las modificaciones de las caracteristicas espectrales de la fibrilacion ventricular en zonas lesionadas con radiofrecuencia. Metodos En 11 preparaciones de corazon aislado y perfundido de conejo, se registra la fibrilacion ventricular con un electrodo multiple epicardico situado en la pared libre ventricular izquierda. Se comparan los parametros espectrales obtenidos mediante analisis de Fourier antes y despues de practicar les…

Effect of chronic exercise and ATP-sensitive potassium channel blockade on the spectral characteristics evolution of ventricular fibrillation in acute regional ischemia

Purpose: It has been proposed that chronic exercise produces a KATP channel blockade in ischemic myocardium. We have also reported that channel blockade and training exert very similar effects on energy required to defibrillate. In fact it is postulated that one mechanism by which exercise exerts an antiarrhythmic effect, is by blocking KATP channel. We have analyzed the evolution of spectrum characteristics of ventricular fibrillation (VF), in normoxic conditions and after acute myocardial ischemia, in isolated hearts from trained rabbits, and in hearts submitted to KATP channel blockade. Our hypothesis is that the spectrum characteristics of VF evolve similarly in trained hearts and in he…

A halocin acting on Na+/H+ exchanger of Haloarchaea as a new type of inhibitor in NHE of mammals

10 páginas, 3 figuras.

Multifunctionality in hybrid molecular materials: design of ferromagnetic molecular metals and hybrid magnets

We report on the synthesis and physical properties of novel hybrid organic–inorganic molecular materials combining ferromagnetic bimetallic oxalato-based networks and functional organic molecules as the donor bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) or cationic nitroxide free radicals. # 2002 Elsevier Science B.V. All rights reserved.

P330Modifications of short-term heart rate varibility and intrinsic pacemaker variability in an experimental model of metabolic syndrome

Effects of chronic exercise on myocardial refractoriness: a study on isolated rabbit heart

Aim:  To determine whether chronic physical training increases atrial and ventricular refractoriness in isolated rabbit heart. Methods:  Trained rabbits were submitted to a protocol of treadmill running. The electrophysiological parameters of refractoriness investigated in an isolated heart preparation were: (1) atrial effective refractory period (AERP) and atrial functional refractory period and ventricular effective and functional refractory periods (VERP and VFRP) using the extrastimulus technique at four different pacing cycle lengths; (2) the dominant frequency (DF) of ventricular fibrillation (VF). A multi-electrode plaque containing 256 electrodes and a spectral method were used to o…

Modificaciones de la fibrilación ventricular y de la capacidad de captura inducidas por una lesión lineal con radiofrecuencia

Resumen Introduccion y objetivos Analizar los efectos, en la fibrilacion ventricular y en la capacidad de capturar al miocardio mediante estimulacion a frecuencias rapidas, de una lesion lineal producida con radiofrecuencia. Metodos En 22 corazones de conejo aislados y perfundidos, se utilizaron electrodos multiples epicardicos para registrar la fibrilacion ventricular. Se analizaron los mapas de activacion al aplicar trenes de estimulos a tres frecuencias distintas, cercanas a las de la arritmia, en tres situaciones: a) basalmente; b) tras producir con radiofrecuencia una lesion en la pared libre del ventriculo izquierdo (longitud, 10 ± 1 mm), y c) tras ampliar su extension (longitud, 23 ±…

Diet-Induced Metabolic Syndrome Reduced Heart Rate Variability and Increased Irregularity and Complexity of Short-Term RR Time Series in Rabbits.

Simple Summary In recent years, obesity and metabolic syndrome (MetS) have become more prevalent, owing to increased unhealthy habits and sedentary lifestyles becoming public health problems. Both conditions are linked with a higher prevalence of sudden cardiac death (SCD), but the exact mechanisms are not known. An autonomic nervous system imbalance can produce atrial and ventricular arrhythmias, which cause SCD, and this can be quantified by analyzing heart rate variability (HRV). We investigated HRV using time-domain, frequency-domain and nonlinear analyses during the development of MetS in rabbits and found HRV modifications that could be associated with the higher prevalence of SCD in …

Hybrid Magnetic Materials Based on Nitroxide Free Radicals and Extended Oxalato‐Bridged Bimetallic Networks

A series of hybrid organic-inorganic magnets of formula p-rad[MIICr(ox)3] [M = Mn (1), Co (2), Ni (3), Zn (4)] and m-rad[MIICr(ox)3] [M = Mn (5), Co (6)], in which N-methylpyridinium cations bearing a nitronyl nitroxide moiety in positions 3 (m-rad) or 4 (p-rad) of the pyridine ring coexist with the 2D honeycomb-like oxalato-bridged bimetallic lattice, has been prepared and studied by AC and DC magnetic susceptibility measurements and EPR spectroscopy. In general, the physical properties of these magnets are not altered significantly by the insertion of the nitronyl nitroxide radicals although these paramagnetic molecules seem to interact weakly with the inorganic network as demonstrated by…

Development and characterization of an experimental model of diet-induced metabolic syndrome in rabbit

Metabolic syndrome (MetS) has become one of the main concerns for public health because of its link to cardiovascular disease. Murine models have been used to study the effect of MetS on the cardiovascular system, but they have limitations for studying cardiac electrophysiology. In contrast, the rabbit cardiac electrophysiology is similar to human, but a detailed characterization of the different components of MetS in this animal is still needed. Our objective was to develop and characterize a diet-induced experimental model of MetS that allows the study of cardiovascular remodeling and arrhythmogenesis. Male NZW rabbits were assigned to control (n = 15) or MetS group (n = 16), fed during 2…

WS 2 /MoS 2 Heterostructures through Thermal Treatment of MoS 2 Layers Electrostatically Functionalized with W 3 S 4 Molecular Clusters

The preparation of 2D stacked layers combining flakes of different nature gives rise to countless numbers of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides, WS2 /MoS2 , has awakened great interest owing to its photovoltaic and photoelectrochemical properties. Solution as well as dry physical methods have been developed to optimize the synthesis of these heterostructures. Here, a suspension of negatively charged MoS2 flakes is mixed with a methanolic solution of a cationi…

WS 2 /MoS 2 Heterostructures through Thermal Treatment of MoS 2 Layers Electrostatically Functionalized with W 3 S 4 Molecular Clusters

Two stage magnetic ordering and spin idle behavior of the coordination polymer Co3(OH)2(C4O4)2·3H2O determined using neutron diffraction.

We report the magnetic structure of two of the magnetically ordered phases of Co(3)(OH)(2)(C(4)O(4))(2)·3H(2)O, a coordination polymer that consists of a triangular framework decorated with anisotropic Co(II) ions. The combination of neutron diffraction experiments and magnetic susceptibility data allows us to identify one phase as displaying spin idle behavior, where only a fraction of the moments order at intermediate temperatures, while at the lowest temperatures the system orders fully. This novel magnetic behavior is discussed within the framework of a simple Hamiltonian and representational analysis and rationalizes this multiphase behavior by considering the combination of frustratio…

Halogen bonding interactions with the [Mo3S7Cl6]2-cluster anion in the mixed valence salt [EDT-TTFI2]4[Mo3S7Cl6]oCH3CN

Electrocrystallization of iodinated TTF molecules in presence of trinuclear [Mo3S7Cl6]2- cluster anions provides the first example of radical salts with halogen bonding interactions at the organic/inorganic interface

Intrinsic changes on automatism, conduction, and refractoriness by exercise in isolated rabbit heart.

We have studied the intrinsic modifications on myocardial automatism, conduction, and refractoriness produced by chronic exercise. Experiments were performed on isolated rabbit hearts. Trained animals were submitted to exercise on a treadmill. The parameters investigated were 1) R-R interval, noncorrected and corrected sinus node recovery time (SNRT) as automatism index; 2) sinoatrial conduction time; 3) Wenckebach cycle length (WCL) and retrograde WCL, as atrioventricular (A-V) and ventriculoatrial conduction index; and 4) effective and functional refractory periods of left ventricle, A-V node, and ventriculoatrial retrograde conduction system. Measurements were also performed on coronary…

Structural diversity in charge transfer salts based on Mo3S7 and Mo3S4Se3 clusters complexes and bis(ethylenedithio)tetrathiafulvalene (ET)

Chemical modification of the trinuclear [Mo3(μ3-S)(μ2-S2)3Br6]2− cluster, at either the outer bromine or the disulfide ligands, allows the facile preparation of the dianions [Mo3(μ3-S)(μ2-S2)3(tdas)3]2− ([1]2−) (tdas = 1,2,5-thiadiazole-3,4-dithiol), [Mo3(μ3-S)(μ2-SSe)3Br6]2− ([2]2−) and [Mo3(μ3-S)(μ2-S2)3Cl6]2− ([3]2−). Electrocrystallization of bis(ethylenedithio)tetrathiafulvalene (ET) in the presence of these dianions affords a series of charge transfer salts, namely (ETA)(ETB)[1], (ETA)(n-Bu4N)[2], (ETA)(ETB)[3]2·CH3CN, and ((ETA)(ETB)(ETC)(ETD))2{[3]2Cl}·CH3CN, where the ET subscripts denote crystallographically independent molecules. In all cases, the various cluster–cluster, cluster…

Time and frequency domain analysis of long-term heart rate variability in an experimental model of diet-induced metabolic syndrome

Abstract Background Metabolic syndrome (MetS) is defined as the set of at least three of the following conditions: central obesity, elevation of triglycerides, decreased in high-density lipoproteins, systemic hypertension and glucose intolerance. MetS is linked with a high prevalence of cardiovascular disease, including sudden cardiac death and atrial arrhythmias, which may be a consequence of changes related to the structure, function and autonomic control of the heart. One of the underlying mechanisms responsible could be the alteration of sinus node automaticity. Heart rate variability (HRV) analysis is a useful non-invasive tool for evaluating alterations in neural control of cardiac au…

A new Co(ii) coordination solid with mixed oxygen, carboxylate, pyridine and thiolate donors exhibiting canted antiferromagnetism with TC≈ 68 K

Reaction of Co(II) chloride with the sodium salt of 2-mercaptonicotinic acid in water at 200 degrees C results in the formation of Co4(2-mna)4(H2O), which orders as a canted antiferromagnet at 68 K.

Protective effect of N-acetylcysteine on ischaemia-induced myocardial damage in canine heart.

The glutathione redox pathway is an important antioxidant system in the myocardium. N-Acetylcysteine is a low molecular weight glutathione precursor that has been used clinically to replenish glutathione stores. The present study was aimed at evaluating the protective effect of N-acetylcysteine on myocardial damage resulting from permanent coronary occlusion (without reperfusion) in anaesthetized dogs. N-Acetylcysteine (150 mg kg−1 i.v.) administered 2 min before occlusion rerduced infarct size in dogs subjected to 24 h ischemia. The infarct size as a percentage of the area at risk was 86.8 ± 3.6% (n = 11) in control (salinetreated) dogs and 68.2 ± 2.4% (n = 7; P < 0.05 vs control) in N-ace…

Effect of Glutathione on Canine Myocardial Ischaemia Without Reperfusion

Abstract The present study was to evaluate the effect of exogenous glutathione on myocardial damage resulting from permanent (no reperfusion) coronary ligation (3 or 6 h) in anaesthetized dogs. Haemodynamics, infarct size and myocardial glutathione content were determined. Erythrocyte superoxide dismutase (SOD) activity was also determined in coronary venous blood samples. Glutathione was administered by the intraperitoneal route, 100 mg kg−1 as initial dose given 5 min before coronary ligation, and successive doses of 25 mg kg−1 every 40 min throughout the study period. Saline-treated dogs showed myocardial infarction, a decrease in myocardial glutathione content, and a transient increase …

Hallazgo de monedas del siglo III en Lequeitio (Vizcaya) en 1803

Durante las obras de la fuente pública de Lequeitio en 1802-1803 se encontraron algunas monedas romanas de las que José Vargas Ponce pudo ver tres en una colección privada de Tolosa. Con los datos proporcionados por el autor es posible identificar el hallazgo como parte de un conjunto monetario del siglo III d.C. 

Heterogeneidades inducidas en el intervalo QT mediante enfriamiento/calentamiento epicárdico local. Estudio experimental

Resumen Introduccion y objetivos La duracion anormal del intervalo QT o su dispersion se han asociado con un incremento en el riesgo de arritmias ventriculares. Se analiza el posible efecto arritmogenico de sus variaciones inducidas mediante enfriamiento y calentamiento local epicardico. Metodos En 10 corazones aislados de conejo, se modifico escalonadamente la temperatura de una region epicardica del ventriculo izquierdo (22 a 42 ° C ), registrando simultaneamente los electrogramas en dicha zona y en otra del mismo ventriculo. En ritmo sinusal, se determino el QT y el intervalo de recuperacion de la activacion y, mediante estimulacion programada, la velocidad de conduccion y la induccion d…

Flow cytometric analysis of peroxidative activity in granulocytes from coronary and peripheral blood in acute myocardial ischemia and reperfusion in dogs: Protective effect of methionine

BACKGROUND Methionine has shown protective effects in experimental models of myocardial infarction and is highly reactive to oxidative compounds produced by polymorphonuclear leukocytes (PMN), which in turn have been associated with myocardial damage. We have investigated the effect of methionine administration on spontaneous leukocyte peroxidative activity in myocardial ischemia and reperfusion. METHODS In anesthetized dogs, with coronary occlusion (90 min) and reperfusion (90 min), PMN activation was measured by flow cytometric determination of H(2)O(2) with dihydrorhodamine 123, and correlated to hemodynamic parameters and infarct presence. To assess a possible direct effect of methionin…

Synthesis of brominated tetrathiafulvalenes via phosphite-mediated cross-coupling

The synthesis of polybrominated tetrathiafulvalenes (TTF-Brn, 2-4) containing 2-4 bromine atoms via phosphite-mediated cross-coupling of bromo-substituted 1,3-dithiole-2-thiones and 1,3-dithiole-2-ones is reported. © 2010 Elsevier B.V.

Evaluación de la complejidad de la activación miocárdica durante la fibrilación ventricular. Estudio experimental

Resumen Introduccion y objetivos Analizar en un modelo experimental las caracteristicas de la fibrilacion ventricular en situaciones con distintos grados de complejidad y establecer la relacion existente entre los datos aportados por distintos metodos de analisis de la arritmia. Metodos En 27 preparaciones de corazon aislado de conejo estudiadas bajo la accion de farmacos (propranolol y KB-R7943) o procedimientos fisicos (estiramiento) que causan distintos grados de variacion de la complejidad de la activacion miocardica durante la arritmia, se han utilizado tecnicas espectrales, morfologicas y cartograficas para procesar los registros obtenidos con multielectrodos epicardicos. Resultados L…

P1605Increased irregularity and spectral complexity of the intrinsic pacemaker beat-to-beat variability correlates with increased metabolic syndrome components

Abstract Background Metabolic syndrome (MetS) is becoming one of the future potential leading risk factors for heart and cardiovascular disease. MetS relates to a condition associated with at least three metabolic risk factors raising risk for health diseases concomitantly such as diabetes, stroke, hypertension, obesity and dyslipidemia. This can lead to chest pain, heart attack, heart damage and overall higher prevalence of cardiovascular disease, atrial fibrillation and sudden cardiac death. One of the underlying mechanisms of the progressive remodeling in presence of MetS components could be altered automaticity, which would reflect modifications of sinus node activity. These phenomena c…

Myocardial Glutathione Alterations in Acute Coronary Occlusion in the Dog

Glutathione (GSH) decreases in dog mycocardium upon acute coronary occlusion when compared with sham-operated dogs. Total glutathione content (GSHeq = GSH + ZGSSG) remains unchanged throughout the experiment (6 h after surgery) in both sham- and acute coronary occlusion-operated dogs. GSSG and GSH/GSSG ratio increases and decreases respectively in all animals but tends to reach the normal value after 6 h in sham-operated dogs. Both parameters (GSSG and GSH/GSSG ratio) remain altered in acute coronary occlusion-operated ones. This alteration of glutathione status in ischemic myocardium is discussed.

A Molecular Metal Ferromagnet from the Organic Donor Bis(ethylenedithio)tetraselenafulvalene and Bimetallic Oxalate Complexes

A new dual-function hybrid molecular material has been obtained from the organic donor bis(ethylenedithio)tetraselenafulvalene and the honeycomb oxalate-based bimetallic network [MnCr(ox)3]-. This multilayer material consists of layers of the inorganic anionic 2D network, responsible for the appearance of ferromagnetic ordering below 5.3 K, alternating with segregated layers of the organic cation radical responsible for the transport properties:  metal-like conductivity is observed from room temperature down to 150 K.

The Effects of Selective Stellate Ganglion Manipulation on Ventricular Refractoriness and Excitability

The effects of selective stellate ganglion stimulation or stellectomy on ventricular excitability were studied in 30 open chest mongrel dogs anesthetized with alpha-chloralose. The effective refractory period (ERP) and strength interval curves (stimulus intensity [S2] = twice the diastolic threshold [ERP], and 2, 3, 5, 7, and 14 mA) were determined using bipolar epicardial electrodes placed in the mid-anterior wall of the right ventricle (RV) and the mid-posterolateral wall of the left ventricle (LV) during left stellate ganglion stimulation (LSGSt, n = 8) or right stellate ganglion stimulation (RSGSt, n = 8), or after left stellectomy (LSGEx, n = 7) or right stellectomy (RSGEx, n = 7). LSG…

A new Co(II) coordination solid with mixed oxygen, carboxylate, pyridine and thiolate donors exhibiting canted antiferromagnetism with TC ≈ K

Reaction of Co(II) chloride with the sodium salt of 2-mercaptonicotinic acid in water at 200 ºC results in the formation of Co4(2-mna)4(H2O), which orders as a canted antiferromagnet at 68 K. Gomez Garcia, Carlos Jose, Carlos.Gomez@uv.es

P315Study of the induction and characteristics of ventricular fibrillation in an experimental model of metabolic syndrome

QT interval heterogeneities induced through local epicardial warming/cooling. An experimental study

[EN] ntroduction and objectives Abnormal QT interval durations and dispersions have been associated with increased risk of ventricular arrhythmias. The present study examines the possible arrhythmogenic effect of inducing QT interval variations through local epicardial cooling and warming. Methods In 10 isolated rabbit hearts, the temperatures of epicardial regions of the left ventricle were modified in a stepwise manner (from 22 °C to 42 °C) with simultaneous electrogram recording in these regions and in others of the same ventricle. QT and activation-recovery intervals were determined during sinus rhythm, whereas conduction velocity and ventricular arrhythmia induction were determined dur…

CCDC 955127: Experimental Crystal Structure Determination

Related Article: Eugenio Coronado, Simona Curreli, Carlos Giménez-Saiz, Carlos J. Gómez-García, Antonio Alberola and Enric Canadell|2009|Inorg.Chem.|48|11314|doi:10.1021/ic9018103

CCDC 955126: Experimental Crystal Structure Determination

Related Article: Eugenio Coronado, Simona Curreli, Carlos Giménez-Saiz, Carlos J. Gómez-García, Antonio Alberola and Enric Canadell|2009|Inorg.Chem.|48|11314|doi:10.1021/ic9018103