92 research outputs found

    Voltammetry under a Controlled Temperature Gradient

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    Electrochemical measurements are generally done under isothermal conditions. Here we report on the application of a controlled temperature gradient between the working electrode surface and the solution. Using electrochemical sensors prepared on ceramic materials with extremely high specific heat conductivity, the temperature gradient between the electrode and solution was applied here as a second driving force. This application of the Soret phenomenon increases the mass transfer in the Nernst layer and enables more accurate control of the electrode response enhancement by a combination of diffusion and thermal diffusion. We have thus studied the effect of Soret phenomenon by cyclic voltammetry measurements in ferro/ferricyanide. The time dependence of sensor response disappears when applying the Soret phenomenon, and the complicated shape of the cyclic voltammogram is replaced by a simple exponential curve. We have derived the Cotrell-Soret equation describing the steady-state response with an applied temperature difference

    Heart transplantation for cardiac light chain amyloidosis with subsequent autologous stem cell transplantation

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    AbstractOur report describes a case of 57-year-old man with manifest heart failure on the basis of cardiac amyloidosis, which was detected by endomyocardial biopsy. Due to the heart failure, the patient was unable to undergo myeloablative therapy. We changed our previous decision for conservative therapy of heart failure and the patient underwent heart transplantation. Autologous stem cell transplantation was performed 6 months later. After the successful stem cell transplantation, the serum free light chain lambda levels promptly decreased. One year later, their levels started again to increase. Chemotherapy was therefore initiated. The patient has now completed the seventh cycle of chemotherapy in good condition. The graft function is normal and the latest endomyocardial biopsy revealed no amyloid

    Clinical Study Comparison of Long-Term Effect of Dual-Chamber Pacing and Alcohol Septal Ablation in Patients with Hypertrophic Obstructive Cardiomyopathy

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    Introduction. Nonpharmacological treatment of patients with hypertrophic obstructive cardiomyopathy (HOCM) comprises surgical myectomy (SME), alcohol septal ablation (ASA), and dual-chamber (DDD) pacing. The aim of the study was to compare the long-term effect of DDD pacing and ASA in symptomatic HOCM patients. Patients and Methods. We evaluated retrospective data from three cardiocenters; there were 24 patients treated with DDD pacing included and 52 treated with ASA followed for 101 ± 49 and 87 ± 23 months, respectively. Results. In the group treated with DDD pacing, the left ventricle outflow tract gradient (LVOTG) decreased from 82 ± 44 mmHg to 21 ± 21 mmHg, and NYHA class improved from 2.7 ± 0.5 to 2.1 ± 0.6 (both < 0.001). In the ASA-treated group, a decline in LVOTG from 73 ± 38 mmHg to 24 ± 26 mmHg and reduction in NYHA class from 2.8 ± 0.5 to 1.7 ± 0.8 were observed (both < 0.001). The LVOTG change was similar in both groups ( = 0.264), and symptoms were more affected by ASA ( = 0.001). Conclusion. ASA and DDD pacing were similarly effective in reducing LVOTG. The symptoms improvement was more expressed in patients treated with ASA

    Outcome of Alcohol Septal Ablation in Mildly Symptomatic Patients With Hypertrophic Obstructive Cardiomyopathy: A Long-Term Follow-Up Study Based on the Euro-Alcohol Septal Ablation Registry

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    Background The long‐term efficacy and safety of alcohol septal ablation ( ASA ) in patients with highly symptomatic hypertrophic obstructive cardiomyopathy has been demonstrated. The aim of this study was to evaluate the long‐term outcomes of mildly symptomatic patients with hypertrophic obstructive cardiomyopathy treated with ASA . Methods and Results We retrospectively evaluated consecutive patients enrolled in the Euro‐ ASA registry (1427 patients) and identified 161 patients (53±13 years; 27% women) who were mildly symptomatic (New York Heart Association [ NYHA ] class II ) pre‐ ASA . The median (interquartile range) follow‐up was 4.8 (1.7–8.5) years. The clinical outcome was assessed and compared with the age‐ and sex‐matched general population. The 30‐day mortality after ASA was 0.6% and the annual all‐cause mortality rate was 1.7%, which was similar to the age‐ and sex‐matched general population ( P =0.62). A total of 141 (88%) patients had resting left ventricular outflow tract gradient at the last clinical checkup ≤30 mm Hg. Obstruction was reduced from 63±32 to 15±19 mm Hg ( P &lt;0.01), and the mean NYHA class decreased from 2.0±0 to 1.3±0.1 ( P &lt;0.01); 69%, 29%, and 2% of patients were in NYHA class I, II , and III at the last clinical checkup, respectively. Conclusions Mildly symptomatic hypertrophic obstructive cardiomyopathy patients treated with ASA had sustained symptomatic and hemodynamic relief with a low risk of developing severe heart failure. Their survival is comparable to the general population. </jats:sec

    Receptor Tyrosine Kinases Activate Canonical WNT/β-Catenin Signaling via MAP Kinase/LRP6 Pathway and Direct β-Catenin Phosphorylation

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    Receptor tyrosine kinase signaling cooperates with WNT/β-catenin signaling in regulating many biological processes, but the mechanisms of their interaction remain poorly defined. We describe a potent activation of WNT/β-catenin by FGFR2, FGFR3, EGFR and TRKA kinases, which is independent of the PI3K/AKT pathway. Instead, this phenotype depends on ERK MAP kinase-mediated phosphorylation of WNT co-receptor LRP6 at Ser1490 and Thr1572 during its Golgi network-based maturation process. This phosphorylation dramatically increases the cellular response to WNT. Moreover, FGFR2, FGFR3, EGFR and TRKA directly phosphorylate β-catenin at Tyr142, which is known to increase cytoplasmic β-catenin concentration via release of β-catenin from membranous cadherin complexes. We conclude that signaling via ERK/LRP6 pathway and direct β-catenin phosphorylation at Tyr142 represent two mechanisms used by various receptor tyrosine kinase systems to activate canonical WNT signaling

    Quality control and quantification in IG/TR next-generation sequencing marker identification: protocols and bioinformatic functionalities by EuroClonality-NGS

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    Assessment of clonality, marker identification and measurement of minimal residual disease (MRD) of immunoglobulin (IG) and T cell receptor (TR) gene rearrangements in lymphoid neoplasms using next-generation sequencing (NGS) is currently under intensive development for use in clinical diagnostics. So far, however, there is a lack of suitable quality control (QC) options with regard to standardisation and quality metrics to ensure robust clinical application of such approaches. The EuroClonality-NGS Working Group has therefore established two types of QCs to accompany the NGS-based IG/TR assays. First, a central polytarget QC (cPT-QC) is used to monitor the primer performance of each of the EuroClonality multiplex NGS assays; second, a standardised human cell line-based DNA control is spiked into each patient DNA sample to work as a central in-tube QC and calibrator for MRD quantification (cIT-QC). Having integrated those two reference standards in the ARResT/Interrogate bioinformatic platform, EuroClonality-NGS provides a complete protocol for standardised IG/TR gene rearrangement analysis by NGS with high reproducibility, accuracy and precision for valid marker identification and quantification in diagnostics of lymphoid malignancies.This work was supported by Ministry of Health of the Czech Republic, grant no. 16-34272A; computational resources were provided by the CESNET LM2015042 and the CERIT Scientific Cloud LM2015085, provided under the programme “Projects of Large Research, Development, and Innovations Infrastructures”. Analyses in Prague (JT, EF and MS) were supported by Ministry of Health, Czech Republic, grant no. 00064203, and by PRIMUS/17/MED/11. Analyses in the Monza (Centro Ricerca Tettamanti, SS, AG and GC) laboratory were supported by the Italian Association for Cancer Research (AIRC) and Comitato Maria Letizia Verga

    Control of Neural Daughter Cell Proliferation by Multi-level Notch/Su(H)/E(spl)-HLH Signaling

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    The Notch pathway controls proliferation during development and in adulthood, and is frequently affected in many disorders. However, the genetic sensitivity and multi-layered transcriptional properties of the Notch pathway has made its molecular decoding challenging. Here, we address the complexity of Notch signaling with respect to proliferation, using the developing Drosophila CNS as model. We find that a Notch/Su(H)/E(spl)-HLH cascade specifically controls daughter, but not progenitor proliferation. Additionally, we find that different E(spl)-HLH genes are required in different neuroblast lineages. The Notch/Su(H)/E(spl)-HLH cascade alters daughter proliferation by regulating four key cell cycle factors: Cyclin E, String/Cdc25, E2f and Dacapo (mammalian p21CIP1/p27KIP1/p57Kip2). ChIP and DamID analysis of Su(H) and E(spl)-HLH indicates direct transcriptional regulation of the cell cycle genes, and of the Notch pathway itself. These results point to a multi-level signaling model and may help shed light on the dichotomous proliferative role of Notch signaling in many other systems

    Heterochromatin Protein 1β (HP1β) has distinct functions and distinct nuclear distribution in pluripotent versus differentiated cells

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    Background: Pluripotent embryonic stem cells (ESCs) have the unique ability to differentiate into every cell type and to self-renew. These characteristics correlate with a distinct nuclear architecture, epigenetic signatures enriched for active chromatin marks and hyperdynamic binding of structural chromatin proteins. Recently, several chromatin-related proteins have been shown to regulate ESC pluripotency and/or differentiation, yet the role of the major heterochromatin proteins in pluripotency is unknown. Results: Here we identify Heterochromatin Protein 1β (HP1β) as an essential protein for proper differentiation, and, unexpectedly, for the maintenance of pluripotency in ESCs. In pluripotent and differentiated cells HP1β is differentially localized and differentially associated with chromatin. Deletion of HP1β, but not HP1aα, in ESCs provokes a loss of the morphological and proliferative characteristics of embryonic pluripotent cells, reduces expression of pluripotency factors and causes aberrant differentiation. However, in differentiated cells, loss of HP1β has the opposite effect, perturbing maintenance of the differentiation state and facilitating reprogramming to an induced pluripotent state. Microscopy, biochemical fractionation and chromatin immunoprecipitation reveal a diffuse nucleoplasmic distribution, weak association with chromatin and high expression levels for HP1β in ESCs. The minor fraction of HP1β that is chromatin-bound in ESCs is enriched within exons, unlike the situation in differentiated cells, where it binds heterochromatic satellite repeats and chromocenters. Conclusions: We demonstrate an unexpected duality in the role of HP1β: it is essential in ESCs for maintaining pluripotency, while it is required for proper differentiation in differentiated cells. Thus, HP1β function both depends on, and regulates, the pluripotent state
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