136 research outputs found
microRNA-vermitteltes atriales Remodeling in einem Schweinemodell für paroxysmales Vorhofflimmern
microRNA-vermitteltes atriales Remodeling in einem Schweinemodell für paroxysmales Vorhofflimmern
A Magyar Mesterséges Táplálási Társaság 2016. évi kongresszusán elhangzó előadások kivonatai. Mátraháza, Lifestyle Hotel Mátra, 2016. október 6–8.
A felnőtt coeliakiások zabfogyasztásának vizsgálata | Melyik tápszert javasoljam a betegemnek?
Dilemmák, lehetőségek és korlátok Magyarországon és Európában | A malnutritio kockázatának önszűrése | A táplálás során végzett ellenőrző vizsgálatok | Az energiaszükséglet meghatározása, az energiaszükséglet mérése – direkt és indirekt kalorimetria | Inkompatibilitásokból származó gyógyszerelési hibák megelőzési stratégiája, a klinikai gyógyszerész szerepe | A preoperatív táplálás fejlesztésének gyakorlati tapasztalatai | A tápszerforgalom és a táplálásterápiás szokások változása hazánkban | Gyári tápoldatkeverékek stabilitása individualizáló kiegészítések nyomán | A táplálásterápia monitorozása gyermekek onkohematológiai betegségében | Gyermekkori onkohematológiai betegség során alkalmazott táplálásterápia
hatása a túlélésre és a túlélő betegek tápláltsági állapotára | Táplálásterápia a súlyos agysérültek korai rehabilitációjának vonatkozásában | Magisztrális parenteralis tápoldatok (Magi-AIO-TPN) eltarthatósága | A Pécsi Tudományegyetem klinikai gyógyszerészi szolgálatának bővítése a táplálásterápia területén | Egészséges mikroflórával a perioperatív szövődmények megelőzéséér
Medetomidine/midazolam/fentanyl narcosis alters cardiac autonomic tone leading to conduction disorders and arrhythmias in mice
Cardiac Macrophages and Their Effects on Arrhythmogenesis
Cardiac electrophysiology is a complex system established by a plethora of inward and outward ion currents in cardiomyocytes generating and conducting electrical signals in the heart. However, not only cardiomyocytes but also other cell types can modulate the heart rhythm. Recently, cardiac macrophages were demonstrated as important players in both electrophysiology and arrhythmogenesis. Cardiac macrophages are a heterogeneous group of immune cells including resident macrophages derived from embryonic and fetal precursors and recruited macrophages derived from circulating monocytes from the bone marrow. Recent studies suggest antiarrhythmic as well as proarrhythmic effects of cardiac macrophages. The proposed mechanisms of how cardiac macrophages affect electrophysiology vary and include both direct and indirect interactions with other cardiac cells. In this review, we provide an overview of the different subsets of macrophages in the heart and their possible interactions with cardiomyocytes under both physiologic conditions and heart disease. Furthermore, we elucidate similarities and differences between human, murine and porcine cardiac macrophages, thus providing detailed information for researchers investigating cardiac macrophages in important animal species for electrophysiologic research. Finally, we discuss the pros and cons of mice and pigs to investigate the role of cardiac macrophages in arrhythmogenesis from a translational perspective
Nutritional Evaluation and Optimisation in Neonates: a randomized, double-blind controlled trial of amino acid regimen and intravenous lipid composition in preterm parenteral nutrition
Background: Parenteral nutrition is central to the care of very immature infants. Current international recommendations favor higher amino acid intakes and fish oil–containing lipid emulsions.
Objective: The aim of this trial was to compare 1) the effects of high [immediate recommended daily intake (Imm-RDI)] and low [incremental introduction of amino acids (Inc-AAs)] parenteral amino acid delivery within 24 h of birth on body composition and 2) the effect of a multicomponent lipid emulsion containing 30% soybean oil, 30% medium-chain triglycerides, 25% olive oil, and 15% fish oil (SMOF) with that of soybean oil (SO)-based lipid emulsion on intrahepatocellular lipid (IHCL) content.
Design: We conducted a 2-by-2 factorial, double-blind, multicenter randomized controlled trial.
Results: We randomly assigned 168 infants born at ,31 wk of
gestation. We evaluated outcomes at term in 133 infants. There were no significant differences between Imm-RDI and Inc-AA groups for nonadipose mass [adjusted mean difference: 1.0 g (95% CI: 2108, 111 g; P = 0.98)] or between SMOF and SO
groups for IHCL [adjusted mean SMOF:SO ratio: 1.1 (95% CI:
0.8, 1.6; P = 0.58]. SMOF does not affect IHCL content. There
was a significant interaction (P = 0.05) between the 2 interventions for nonadipose mass. There were no significant interactions between group differences for either primary outcome measure after adjusting for additional confounders. Imm-RDI infants were more likely than Inc-AA infants to have blood urea nitrogen concentrations .7 mmol/L or .10 mmol/L, respectively (75% compared with 49%, P , 0.01; 49% compared with 18%, P , 0.01). Head circumference at term was smaller in the Imm-RDI group [mean difference: 20.8 cm (95% CI: 21.5, 20.1 cm; P = 0.02)]. There were no significant differences in any prespecified secondary outcomes, including adiposity, liver function tests, incidence of conjugated hyperbilirubinemia, weight, length, mortality, and brain volumes.
Conclusion: Imm-RDI of parenteral amino acids does not benefit body composition or growth to term and may be harmful. This trial was registered at www.isrctn.com as ISRCTN29665319 and at eudract.ema.europa.eu as EudraCT 2009-016731-34
Functional Characterization of a Spectrum of Novel Romano-Ward Syndrome KCNQ1 Variants
The KCNQ1 gene encodes the α-subunit of the cardiac voltage-gated potassium (Kv) channel KCNQ1, also denoted as Kv7.1 or KvLQT1. The channel assembles with the ß-subunit KCNE1, also known as minK, to generate the slowly activating cardiac delayed rectifier current IKs, a key regulator of the heart rate dependent adaptation of the cardiac action potential duration (APD). Loss-of-function variants in KCNQ1 cause the congenital Long QT1 (LQT1) syndrome, characterized by delayed cardiac repolarization and a QT interval prolongation in the surface electrocardiogram (ECG). Autosomal dominant loss-of-function variants in KCNQ1 result in the LQT syndrome called Romano-Ward syndrome (RWS), while autosomal recessive variants affecting function, lead to Jervell and Lange-Nielsen syndrome (JLNS), associated with deafness. The aim of this study was the characterization of novel KCNQ1 variants identified in patients with RWS to widen the spectrum of known LQT1 variants, and improve the interpretation of the clinical relevance of variants in the KCNQ1 gene. We functionally characterized nine human KCNQ1 variants using the voltage-clamp technique in Xenopus laevis oocytes, from which we report seven novel variants. The functional data was taken as input to model surface ECGs, to subsequently compare the functional changes with the clinically observed QTc times, allowing a further interpretation of the severity of the different LQTS variants. We found that the electrophysiological properties of the variants correlate with the severity of the clinically diagnosed phenotype in most cases, however, not in all. Electrophysiological studies combined with in silico modelling approaches are valuable components for the interpretation of the pathogenicity of KCNQ1 variants, but assessing the clinical severity demands the consideration of other factors that are included, for example in the Schwartz score
Atrial fibrosis heterogeneity is a risk for atrial fibrillation in pigs with ischaemic heart failure
Background
Atrial fibrillation (AF) is the most common arrhythmia and is associated with considerable morbidity and mortality. Ischaemic heart failure (IHF) remains one of the most common causes of AF in clinical practice. However, ischaemia-mediated mechanisms leading to AF are still incompletely understood, and thus, current treatment approaches are limited. To improve our understanding of the pathophysiology, we studied a porcine IHF model.
Methods
In pigs, IHF was induced by balloon occlusion of the left anterior descending artery for 90 min. After 30 days of reperfusion, invasive haemodynamic measurements and electrophysiological studies were performed. Masson trichrome and immunofluorescence staining were conducted to assess interstitial fibrosis and myofibroblast activation in different heart regions.
Results
After 30 days of reperfusion, heart failure with significantly reduced ejection fraction (left anterior obique 30°, 34.78 ± 3.29% [IHF] vs. 62.03 ± 2.36% [control], p < .001; anterior–posterior 0°, 29.16 ± 3.61% vs. 59.54 ± 1.09%, p < .01) was observed. These pigs showed a significantly higher susceptibility to AF (33.90% [IHF] vs. 12.98% [control], p < .05). Histological assessment revealed aggravated fibrosis in atrial appendages but not in atrial free walls in IHF pigs (11.13 ± 1.44% vs. 5.99 ± .86%, p < .01 [LAA], 8.28 ± .56% vs. 6.01 ± .35%, p < .01 [RAA]), which was paralleled by enhanced myofibroblast activation (12.09 ± .65% vs. 9.00 ± .94%, p < .05 [LAA], 14.37 ± .60% vs. 10.30 ± 1.41%, p < .05 [RAA]). Correlation analysis indicated that not fibrosis per se but its cross-regional heterogeneous distribution across the left atrium was associated with AF susceptibility (r = .6344, p < .01).
Conclusion
Our results suggest that left atrial cross-regional fibrosis difference rather than overall fibrosis level is associated with IHF-related AF susceptibility, presumably by establishing local conduction disturbances and heterogeneity
Biomarker Periodic Repolarization Dynamics Indicates Enhanced Risk for Arrhythmias and Sudden Cardiac Death in Myocardial Infarction in Pigs
Background
Periodic repolarization dynamics (PRD) is an electrocardiographic biomarker that captures repolarization instability in the low frequency spectrum and is believed to estimate the sympathetic effect on the ventricular myocardium. High PRD indicates an increased risk for postischemic sudden cardiac death (SCD). However, a direct link between PRD and proarrhythmogenic autonomic remodeling has not yet been shown.
Methods and Results
We investigated autonomic remodeling in pigs with myocardial infarction (MI)–related ischemic heart failure induced by balloon occlusion of the left anterior descending artery (n=17) compared with pigs without MI (n=11). Thirty days after MI, pigs demonstrated enhanced sympathetic innervation in the infarct area, border zone, and remote left ventricle paralleled by altered expression of autonomic marker genes/proteins. PRD was enhanced 30 days after MI compared with baseline (pre‐MI versus post‐MI: 1.75±0.30 deg2 versus 3.29±0.79 deg2, P<0.05) reflecting pronounced autonomic alterations on the level of the ventricular myocardium. Pigs with MI‐related ventricular fibrillation and SCD had significantly higher pre‐MI PRD than pigs without tachyarrhythmias, suggesting a potential role for PRD as a predictive biomarker for ischemia‐related arrhythmias (no ventricular fibrillation versus ventricular fibrillation: 1.50±0.39 deg2 versus 3.18±0.53 deg2 [P<0.05]; no SCD versus SCD: 1.67±0.32 deg2 versus 3.91±0.63 deg2 [P<0.01]).
Conclusions
We demonstrate that ischemic heart failure leads to significant proarrhythmogenic autonomic remodeling. The concomitant elevation of PRD levels in pigs with ischemic heart failure and pigs with MI‐related ventricular fibrillation/SCD suggests PRD as a biomarker for autonomic remodeling and as a potential predictive biomarker for ventricular arrhythmias/survival in the context of MI
Characterization of a porcine model of atrial arrhythmogenicity in the context of ischaemic heart failure
Atrial fibrillation (AF) is a major healthcare challenge contributing to high morbidity and mortality. Treatment options are still limited, mainly due to insufficient understanding of the underlying pathophysiology. Further research and the development of reliable animal models resembling the human disease phenotype is therefore necessary to develop novel, innovative and ideally causal therapies. Since ischaemic heart failure (IHF) is a major cause for AF in patients we investigated AF in the context of IHF in a close-tohuman porcine ischaemia-reperfusion model. Myocardial infarction (AMI) was induced in propofol/fentanyl/ midazolam-anaesthetized pigs by occluding the left anterior descending artery for 90 minutes to model ischaemia with reperfusion. After 30 days ejection fraction (EF) was significantly reduced and haemodynamic parameters (pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), left ventricular enddiastolic pressure (LVEDP)) were significantly elevated compared to age/weight matched control pigs without AMI, demonstrating an IHF phenotype. Electrophysiological properties (sinus node recovery time (SNRT), atrial/AV nodal refractory periods (AERP, AVERP)) did not differ between groups. Atrial burst pacing at 1200 bpm, however, revealed a significantly higher inducibility of atrial arrhythmia episodes including AF in IHF pigs (3/15 vs. 10/16, p = 0.029). Histological analysis showed pronounced left atrial and left ventricular fibrosis demonstrating a structural substrate underlying the increased arrhythmogenicity. Consequently, selective ventricular infarction via LAD occlusion causes haemodynamic alterations inducing structural atrial remodeling which results in increased atrial fibrosis as the arrhythmogenic atrial substrate in pigs with IHF
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