100 research outputs found

    Nucleoside diphosphate kinase B is required for the formation of heterotrimeric G protein containing caveolae.

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    Caveolae are flask-shaped invaginations in the plasma membrane that serve to compartmentalize and organize signal transduction processes, including signals mediated by G protein-coupled receptors and heterotrimeric G proteins. Herein we report evidence for a close association of the nucleoside diphosphate kinase B (NDPK B) and caveolin proteins which is required for G protein scaffolding and caveolae formation. A concomitant loss of the proteins NDPK B, caveolin isoforms 1 (Cav1) and 3, and heterotrimeric G proteins occurred when one of these proteins was specifically depleted in zebrafish embryos. Co-immunoprecipitation of Cav1 with the G protein Gβ-subunit and NDPK B from zebrafish lysates corroborated the direct association of these proteins. Similarly, in embryonic fibroblasts from the respective knockout (KO) mice, the membrane content of the Cav1, Gβ, and NDPK B was found to be mutually dependent on one another. A redistribution of Cav1 and Gβ from the caveolae containing fractions of lower density to other membrane compartments with higher density could be detected by means of density gradient fractionation of membranes derived from NDPK A/B KO mouse embryonic fibroblasts (MEFs) and after shRNA-mediated NDPK B knockdown in H10 cardiomyocytes. This redistribution could be visualized by confocal microscopy analysis showing a decrease in the plasma membrane bound Cav1 in NDPK A/B KO cells and vice versa and a decrease in the plasma membrane pool of NDPK B in Cav1 KO cells. Consequently, ultrastructural analysis revealed a reduction of surface caveolae in the NDPK A/B KO cells. To prove that the disturbed subcellular localization of Cav1 in NDPK A/B KO MEFs as well as NDPK B in Cav1 KO MEFs is a result of the loss of NDPK B and Cav1, respectively, we performed rescue experiments. The adenoviral re-expression of NDPK B in NDPK A/B KO MEFs rescued the protein content and the plasma membrane localization of Cav1. The expression of an EGFP-Cav1 fusion protein in Cav1-KO cells induced a restoration of NDPK B expression levels and its appearance at the plasma membrane. We conclude from these findings that NDPK B, heterotrimeric G proteins, and caveolins are mutually dependent on each other for stabile localization and caveolae formation at the plasma membrane. The data point to a disturbed transport of caveolin/G protein/NDPK B complexes from intracellular membrane compartments if one of the components is missing

    Predictors of early scaffold thrombosis: results from the multicenter prospective German-Austrian ABSORB RegIstRy

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    Background: In randomized clinical trials, the risk of thrombotic events with the absorb bioresorbable vascular scaffold (BVS) was significantly higher than with metallic drug-eluting stents. We evaluated predictors of scaffold thrombosis in the large-scale, multicenter German-Austrian ABSORB RegIstRy.Methods and Results: 3178 patients with treatment of 4252 lesions using 5020 scaffolds were included. Follow-up rate at 6 months was 97.4%. Forty-five (1.42%) patients experienced definite/probable scaffold thrombosis during follow-up. Multiple regression analysis showed implantation of absorb BVS in bifurcation lesions [odds ratio (OR): 4.43;95% confidence interval (CI): 1.69-11.59;P=0.0024] or treatment in the years 2013/2014 (OR: 1.88;95% CI: 1.02-3.47;P=0.04) to be significant predictors of scaffold thrombosis. Excluding bifurcation lesions, the incidence of definite/probable scaffold thrombosis decreased from 1.8% (95% CI: 1.17-2.64%) in 2013/2014 to 0.89% (95% CI: 0.5-1.46%) in 2015/2016. In the latter period, absorb BVS were implanted more often in younger patients with less complex de novo lesions, and debulking devices and postdilatation were used more frequently. Between the two treatment periods, there was a significant reduction in myocardial infarction (2.73-1.24%, P<0.01;OR: 0.45;95% CI: 0.26-0.77), definite/probable scaffold thrombosis (1.79-0.88%, P<0.05;OR: 0.49;95% CI: 0.26-0.93), and target lesion failure and revascularization during follow-up.Conclusion: Improved procedural technique and more strict patient selection may explain a significant decrease in the absorb BVS thrombosis rates during the recruitment period of the large-scale German-Austrian ABSORB RegIstRy. In addition, treatment of bifurcation lesions was identified as an independent predictor of definite/probable scaffold thrombosis

    Comparison of transcatheter edge-to-edge and surgical repair in patients with functional mitral regurgitation using a meta-analytic approach

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    BackgroundEvidence regarding favorable treatment of patients with functional mitral regurgitation (FMR) using transcatheter edge-to-edge repair (TEER) is constantly growing. However, there is only few data directly comparing TEER and surgical mitral valve repair (SMVr).AimsTo compare baseline characteristics, short-term and 1-year outcomes in FMR patients undergoing mitral valve (MV) TEER or SMVr using a meta-analytic approach.MethodsSystematic database search identified 1,703 studies reporting on TEER or SMVr for treatment of FMR between January 2010 and December 2020. A meta-analytic approach was used to compare outcomes from single-arm and randomized studies based on measures by means of their corresponding 95% confidence intervals (CI). Statistical significance was assumed if CIs did not overlap. A total of 21 TEER and 37 SMVr studies comprising 4,304 and 3,983 patients were included.ResultsPatients in the TEER cohort presented with higher age (72.0 ± 1.7 vs. 64.7 ± 4.7 years, p &lt; 0.001), greater burden of comorbidities like hypertension (p &lt; 0.001), atrial fibrillation (p &lt; 0.001), lung disease (p &lt; 0.001) and chronic renal disease (p = 0.005) as well as poorer left ventricular ejection fraction (30.9 ± 5.7 vs. 36.6 ± 5.3%, p &lt; 0.001). In-hospital mortality was significantly lower with TEER [3% (95%-CI 0.02–0.03) vs. 5% (95%-CI 0.04–0.07)] and 1-year mortality did not differ significantly [18% (95%-CI 0.15–0.21) vs. 11% (0.07–0.18)]. NYHA [1.06 (95%-CI 0.87–1.26) vs. 1.15 (0.74–1.56)] and MR reduction [1.74 (95%-CI 1.52–1.97) vs. 2.08 (1.57–2.59)] were comparable between both cohorts.ConclusionDespite considerably higher age and comorbidity burden, in-hospital mortality was significantly lower in FMR patients treated with TEER, whereas a tendency toward increased 1-year mortality was observed in this high-risk population. In terms of functional status and MR grade reduction, comparable 1-year results were achieved

    Adverse events in families with hypertrophic or dilated cardiomyopathy and mutations in the MYBPC3 gene

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    <p>Abstract</p> <p>Background</p> <p>Mutations in <it>MYBPC3 </it>encoding myosin binding protein C belong to the most frequent causes of hypertrophic cardiomyopathy (HCM) and may also lead to dilated cardiomyopathy (DCM). <it>MYBPC3 </it>mutations initially were considered to cause a benign form of HCM. The aim of this study was to examine the clinical outcome of patients and their relatives with 18 different <it>MYBPC3 </it>mutations.</p> <p>Methods</p> <p>87 patients with HCM and 71 patients with DCM were screened for <it>MYBPC3 </it>mutations by denaturing gradient gel electrophoresis and sequencing. Close relatives of mutation carriers were genotyped for the respective mutation. Relatives with mutation were then evaluated by echocardiography and magnetic resonance imaging. A detailed family history regarding adverse clinical events was recorded.</p> <p>Results</p> <p>In 16 HCM (18.4%) and two DCM (2.8%) index patients a mutation was detected. Seven mutations were novel. Mutation carriers exhibited no additional mutations in genes <it>MYH7</it>, <it>TNNT2</it>, <it>TNNI3</it>, <it>ACTC </it>and <it>TPM1</it>. Including relatives of twelve families, a total number of 42 mutation carriers was identified of which eleven (26.2%) had at least one adverse event. Considering the twelve families and six single patients with mutations, 45 individuals with cardiomyopathy and nine with borderline phenotype were identified. Among the 45 patients, 23 (51.1%) suffered from an adverse event. In eleven patients of seven families an unexplained sudden death was reported at the age between 13 and 67 years. Stroke or a transient ischemic attack occurred in six patients of five families. At least one adverse event occurred in eleven of twelve families.</p> <p>Conclusion</p> <p><it>MYBPC3 </it>mutations can be associated with cardiac events such as progressive heart failure, stroke and sudden death even at younger age. Therefore, patients with <it>MYBPC3 </it>mutations require thorough clinical risk assessment.</p

    Коррекция двигательных и поведенческих функций в лечении и реабилитации больных шизотипическим расстройством

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    На основании особенностей невербального поведения больных шизотипическим расстройством разработаны поведенческие методы, применение которых в их комплексной терапии позволяет добиться более полной редукции психопатологической симптоматики.Behavioral methods were worked out basing of the peculiarities of non−verbal behavior of the patients with schizotypical disorders. The use of the methods in complex therapy allows to achieve more complete reduction in psychopathological signs

    Impact of aspirin on takotsubo syndrome: a propensity score-based analysis of the InterTAK Registry

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    Aims: The aim of the present study was to investigate the impact of aspirin on prognosis in takotsubo syndrome (TTS). Methods and results: Patients from the International Takotsubo (InterTAK) Registry were categorized into two groups based on aspirin prescription at discharge. A comparison of clinical outcomes between groups was performed using an adjusted analysis with propensity score (PS) stratification; results from the unadjusted analysis were also reported to note the effect of the PS adjustment. Major adverse cardiac and cerebrovascular events (MACCE: a composite of death, myocardial infarction, TTS recurrence, stroke or transient ischaemic attack) were assessed at 30-day and 5-year follow-up. A total of 1533 TTS patients with known status regarding aspirin prescription at discharge were included. According to the adjusted analysis based on PS stratification, aspirin was not associated with a lower hazard of MACCE at 30-day [hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.50\u20133.04, P&nbsp;=&nbsp;0.64] or 5-year follow-up (HR 1.11, 95% CI 0.78\u20131.58, P&nbsp;=&nbsp;0.58). These results were confirmed by sensitivity analyses performed with alternative PS-based methods, i.e. covariate adjustment and inverse probability of treatment weighting. Conclusion: In the present study, no association was found between aspirin use in TTS patients and a reduced risk of MACCE at 30-day and 5-year follow-up. These findings should be confirmed in adequately powered randomized controlled trials. ClinicalTrials.gov Identifier: NCT01947621

    3D finite element electrical model of larval zebrafish ECG signals

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    Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace’s equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions

    Heavy and light roles: myosin in the morphogenesis of the heart

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    Myosin is an essential component of cardiac muscle, from the onset of cardiogenesis through to the adult heart. Although traditionally known for its role in energy transduction and force development, recent studies suggest that both myosin heavy-chain and myosin lightchain proteins are required for a correctly formed heart. Myosins are structural proteins that are not only expressed from early stages of heart development, but when mutated in humans they may give rise to congenital heart defects. This review will discuss the roles of myosin, specifically with regards to the developing heart. The expression of each myosin protein will be described, and the effects that altering expression has on the heart in embryogenesis in different animal models will be discussed. The human molecular genetics of the myosins will also be reviewed

    Impact of atrial fibrillation on outcome in Takotsubo syndrome: data from the international Takotsubo registry

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    Background Atrial fibrillation (AF) is a major risk factor for mortality. The prevalence, clinical correlates, and prognostic impact of AF in Takotsubo syndrome (TTS) have not yet been investigated in a large patient cohort. This study aimed to investigate the prevalence, clinical correlates, and prognostic impact of AF in patients with TTS. Methods and Results Patients with TTS were enrolled from the International Takotsubo Registry, which is a multinational network with 26 participating centers in Europe and the United States. Patients were dichotomized according to the presence or absence of AF at the time of admission. Of 1584 patients with TTS, 112 (7.1%) had AF. The mean age was higher (P<0.001), and there were fewer women (P=0.046) in the AF than in the non-AF group. Left ventricular ejection fraction was significantly lower (P=0.001), and cardiogenic shock was more often observed (P<0.001) in the AF group. Both in-hospital (P<0.001) and long-term mortality (P<0.001) were higher in the AF group. Multivariable Cox regression analysis revealed that AF was independently associated with higher long-term mortality (hazard ratio, 2.31; 95% CI, 1.50-3.55; P<0.001). Among patients with AF on admission, 42% had no known history of AF before the acute TTS event, and such patients had comparable in-hospital and long-term outcomes compared with those with a history of AF. Conclusions In patients presenting with TTS, AF on admission is significantly associated with increased in-hospital and long-term mortality rates. Whether antiarrhythmics and/or cardioversion are beneficial in TTS with AF should thus be tested in a future trial. Registration URL: ; Unique identifier: NCT01947621.Cardiolog
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