Statistical Testing for Protein Equivalence Identifies Core Functional Modules Conserved across 360 Cancer Cell Lines and Presents a General Approach to Investigating Biological Systems.

Quantitative proteomics has enhanced our capability to study protein dynamics and their involvement in disease using various techniques, including statistical testing, to discern the significant differences between conditions. While most focus is on what is different between conditions, exploring similarities can provide valuable insights. However, exploring similarities directly from the analyte level, such as proteins, genes, or metabolites, is not a standard practice and is not widely adopted. In this study, we propose a statistical framework called QuEStVar (Quantitative Exploration of Stability and Variability through statistical hypothesis testing), enabling the exploration of quantitative stability and variability of features with a combined statistical framework. QuEStVar utilizes differential and equivalence testing to expand statistical classifications of analytes when comparing conditions. We applied our method to an extensive data set of cancer cell lines and revealed a quantitatively stable core proteome across diverse tissues and cancer subtypes. The functional analysis of this set of proteins highlighted the molecular mechanism of cancer cells to maintain constant conditions of the tumorigenic environment via biological processes, including transcription, translation, and nucleocytoplasmic transport.

The Eµ-Ret mouse is a novel model of hyperdiploid B-cell acute lymphoblastic leukemia.

The presence of supernumerary chromosomes is the only abnormality shared by all patients diagnosed with high-hyperdiploid B cell acute lymphoblastic leukemia (HD-ALL). Despite being the most frequently diagnosed pediatric leukemia, the lack of clonal molecular lesions and complete absence of appropriate experimental models have impeded the elucidation of HD-ALL leukemogenesis. Here, we report that for 23 leukemia samples isolated from moribund Eµ-Ret mice, all were characterized by non-random chromosomal gains, involving combinations of trisomy 9, 12, 14, 15, and 17. With a median gain of three chromosomes, leukemia emerged after a prolonged latency from a preleukemic B cell precursor cell population displaying more diverse aneuploidy. Transition from preleukemia to overt disease in Eµ-Ret mice is associated with acquisition of heterogeneous genomic abnormalities affecting the expression of genes implicated in pediatric B-ALL. The development of abnormal centrosomes in parallel with aneuploidy renders both preleukemic and leukemic cells sensitive to inhibitors of centrosome clustering, enabling targeted in vivo depletion of leukemia-propagating cells. This study reveals the Eµ-Ret mouse to be a novel tool for investigating HD-ALL leukemogenesis, including supervision and selection of preleukemic aneuploid clones by the immune system and identification of vulnerabilities that could be targeted to prevent relapse.

In-Hospital Pulmonary Arterial Embolism after Catheter Ablation of Over 45,000 Cardiac Arrhythmias: Individualized Case Analysis of Multicentric Data.

OBJECTIVE AND BACKGROUND: Data on incidence of in-hospital pulmonary embolisms (PE) after catheter ablation (CA) are scarce. To gain further insights, we sought to provide new findings through case-based analyses of administrative data. METHODS: Incidences of PE after CA of supraventricular tachycardias (SVT), atrial fibrillation (AF), atrial flutter (AFlu), and ventricular tachycardias (VT) in three German tertiary centers between 2005 and 2020 were determined and coded by the G-DRG (German Diagnosis Related Groups System) and OPS (German Operation and Procedure Classification) systems. An administrative search was performed with a consecutive case-based analysis. RESULTS: Overall, 47,344 ablations were analyzed (10,037 SVT; 28,048 AF; 6,252 AFlu; 3,007 VT). PE occurred in 14 (0.03%) predominantly female (n = 9; 64.3%) patients with a mean age of 55.3 ± 16.9 years, body mass index 26.2 ± 5.1 kg/m2, and left ventricular ejection fraction of 56 ± 13.6%. PE incidences were 0.05% (n = 5) for SVT, 0.02% (n = 5) for AF, and 0.13% (n = 4) for VT ablations. No patient suffered PE after AFlu ablation. Five patients (35.7%) with PE after CA had no prior indication for oral anticoagulation (OAC). Preprocedural international normalized ratio in PE patients was 1.2 ± 0.5. Most patients with PE following CA presented with symptoms the day after the procedure (n = 9) after intraprocedural heparin application of 12,943.2 ± 5,415.5 IU. PE treatment included anticoagulation with either phenprocoumon (n = 5) or non-vitamin K-dependent OAC (n = 9). Two patients with PE died after VT/AF ablation, respectively. The remaining patients were discharged without sequels. CONCLUSION: Over a 15-year period, incidence of PE after ablation is low, particularly low in patients with ablation for AF/AFlu. This is most likely due to stricter anticoagulation management in these patients compared with those receiving SVT/VT ablation procedures and could argue for continuation of OAC prior to ablation. Optimizing periprocedural anticoagulation management should be subject of further prospective trials.

Relevance of mexiletine in the era of evolving antiarrhythmic therapy of ventricular arrhythmias.

Despite impressive developments in the field of ventricular arrhythmias, there is still a relevant number of patients with ventricular arrhythmias who require antiarrhythmic drug therapy and may, e.g., in otherwise drug and/or ablation refractory situations, benefit from agents known for decades, such as mexiletine. Through its capability of blocking fast sodium channels in cardiomyocytes, it has played a minor to moderate antiarrhythmic role throughout the recent decades. Nevertheless, certain patients with structural heart disease suffering from drug-refractory, i.e., mainly amiodarone refractory ventricular arrhythmias, as well as those with selected forms of congenital long QT syndrome (LQTS) may nowadays still benefit from mexiletine. Here, we outline mexiletine's cellular and clinical electrophysiological properties. In addition, the application of mexiletine may be accompanied by various potential side effects, e.g., nausea and tremor, and is limited by several drug-drug interactions. Thus, we shed light on the current therapeutic role of mexiletine for therapy of ventricular arrhythmias and discuss clinically relevant aspects of its indications based on current evidence.

Feasibility and efficacy of a novel size adjustable cryoballoon for ablation of atrial fibrillation.

The aim of the present case series was to characterize the feasibility of a novel size adjustable cryoballoon system (PolarX Fit, Boston Scientific, Marlborough, MA, USA). This cryoballoon catheter can be inflated to two different diameters (28 mm and 31 mm) within the same procedure allowing vein adapted PVI. In summary, the novel size adjustable cryoballoon shows similar characteristics as the established versions. The intraprocedural flexibility of balloon size led to employment of the larger variant in the majority of freeze applications. Of note, in all but one procedure, both sizes were employed to ensure optimal occlusion for all veins. This initial series suggests that the size adjustable balloon offers more flexibility of obtain optimal occlusions in particular, in challenging anatomies, including common pulmonary vein ostia.

Major in-hospital complications after catheter ablation of cardiac arrhythmias: individual case analysis of 43 031 procedures.

AIMS: In-hospital complications of catheter ablation for atrial fibrillation (AF), atrial flutter (AFL), and ventricular tachycardia (VT) may be overestimated by analyses of administrative data. METHODS AND RESULTS: We determined the incidences of in-hospital mortality, major bleeding, and stroke around AF, AFL, and VT ablations in four German tertiary centres between 2005 and 2020. All cases were coded by the G-DRG- and OPS-systems. Uniform code search terms were applied defining both the types of ablations for AF, AFL, and VT and the occurrence of major adverse events including femoral vascular complications, iatrogenic tamponade, stroke, and in-hospital death. Importantly, all complications were individually reviewed based on patient-level source records. Overall, 43 031 ablations were analysed (30 361 AF; 9364 AFL; 3306 VT). The number of ablations/year more than doubled from 2005 (n = 1569) to 2020 (n = 3317) with 3 times and 2.5 times more AF and VT ablations in 2020 (n = 2404 and n = 301, respectively) as compared to 2005 (n = 817 and n = 120, respectively), but a rather stable number of AFL ablations (n = 554 vs. n = 612). Major peri-procedural complications occurred in 594 (1.4%) patients. Complication rates were 1.1% (n = 325) for AF, 1.0% (n = 95) for AFL, and 5.3% (n = 175) for VT. With an increase in complex AF/VT procedures, the overall complication rate significantly increased (0.76% in 2005 vs. 1.81% in 2020; P = 0.004); but remained low over time. Following patient-adjudication, all in-hospital cardiac tamponades (0.7%) and strokes (0.2%) were related to ablation. Major femoral vascular complications requiring surgical intervention occurred in 0.4% of all patients. The in-hospital mortality rate adjudicated to be ablation-related was lower than the coded mortality rate: AF: 0.03% vs. 0.04%; AFL: 0.04% vs. 0.14%; VT: 0.42% vs. 1.48%. CONCLUSION: Major adverse events are low and comparable after catheter ablation for AFL and AF (∼1.0%), whereas they are five times higher for VT ablations. In the presence of an increase in complex ablation procedures, a moderate but significant increase in overall complications from 2005-20 was observed. Individual case analysis demonstrated a lower than coded ablation-related in-hospital mortality. This highlights the importance of individual case adjudication when analysing administrative data.

Temperature to time Catch-Up: a novel procedural endpoint to predict durable pulmonary vein isolation after cryoballoon ablation of paroxysmal atrial fibrillation.

BACKGROUND: Cryoballoon ablation is a widely used single-shot technique for pulmonary vein isolation (PVI) in the treatment of paroxysmal atrial fibrillation (AF). Procedural endpoints ensuring maximal PVI durability are important. OBJECTIVE: To assess the performance of cryoablation procedural markers to predict long-term PVI. METHODS: In a single center, consecutive patients who underwent redo ablation with high-density mapping for symptomatic AF recurrence after cryoballoon ablation were included and cryoballoon procedural data were collected, including temperature values at 30 and 60 s, time to isolation, nadir temperature and the velocity of temperature decline estimated with the temperature/time catch-up point (T2T-Catch-Up) defined as positive when the freeze temperature in minus degree equals the time in seconds after cryoablation initiation (e.g. - 15 °C in the first 15 s of the ablation impulse). RESULTS: 47 patients (62% male; 58.3 ± 11.2 years) were included. Overall, 38 (80.9%) patients had ≥ 1 reconnected PV. Among 186 PVs, 56 (30.1%; 1.2 per patient on average) were reconnected. Univariate analysis revealed T2T-Catch-Up in 103 (56%) and more frequent in durably isolated than in reconnected PVs (93 [72%] vs 10 [19%], p < 0.0001). Among binary endpoints, T2T-Catch-Up had the highest specificity (82%) and predictive value for durable PVI at redo ablation (90%). In multivariable analyses, absence of T2T-Catch-Up (Odds-ratio 0.12, 95% CI [0.05-0.31], p < 0.0001) and right superior PV (Odds-ratio 3.14, 95% CI [1.27-7.74], p = 0.01) were the only variables independently associated with PV reconnection. CONCLUSION: T2T-Catch-Up, a new and simple cryoballoon procedural endpoint demonstrated excellent predictive value and strong statistical association with durable PVI.

Targetable lesions and proteomes predict therapy sensitivity through disease evolution in pediatric acute lymphoblastic leukemia.

Childhood acute lymphoblastic leukemia (ALL) genomes show that relapses often arise from subclonal outgrowths. However, the impact of clonal evolution on the actionable proteome and response to targeted therapy is not known. Here, we present a comprehensive retrospective analysis of paired ALL diagnosis and relapsed specimen. Targeted next generation sequencing and proteome analysis indicate persistence of actionable genome variants and stable proteomes through disease progression. Paired viably-frozen biopsies show high correlation of drug response to variant-targeted therapies but in vitro selectivity is low. Proteome analysis prioritizes PARP1 as a pan-ALL target candidate needed for survival following cellular stress; diagnostic and relapsed ALL samples demonstrate robust sensitivity to treatment with two PARP1/2 inhibitors. Together, these findings support initiating prospective precision oncology approaches at ALL diagnosis and emphasize the need to incorporate proteome analysis to prospectively determine tumor sensitivities, which are likely to be retained at disease relapse.

Lidocaine as an anti-arrhythmic drug: Are there any indications left?

Lidocaine is classified as a class Ib anti-arrhythmic that blocks voltage- and pH-dependent sodium channels. It exhibits well investigated anti-arrhythmic effects and has been the anti-arrhythmic of choice for the treatment of ventricular arrhythmias for several decades. Lidocaine binds primarily to inactivated sodium channels, decreases the action potential duration, and increases the refractory period. It increases the ventricular fibrillatory threshold and can interrupt life-threatening tachycardias caused by re-entrant mechanisms, especially in ischemic tissue. Its use was pushed into the background in the era of amiodarone and modern electric device therapy. Recently, lidocaine has come back into focus for the treatment of acute sustained ventricular tachyarrhythmias. In this brief overview, we review the clinical pharmacology including possible side effects, the historical course, possible indications, and current Guideline recommendations for the use of lidocaine.

Shift of the insoluble content of the proteome in the aging mouse brain.

During aging, the cellular response to unfolded proteins is believed to decline, resulting in diminished proteostasis. In model organisms, such as Caenorhabditis elegans, proteostatic decline with age has been linked to proteome solubility shifts and the onset of protein aggregation. However, this correlation has not been extensively characterized in aging mammals. To uncover age-dependent changes in the insoluble portion of a mammalian proteome, we analyzed the detergent-insoluble fraction of mouse brain tissue by mass spectrometry. We identified a group of 171 proteins, including the small heat shock protein α-crystallin, that become enriched in the detergent-insoluble fraction obtained from old mice. To enhance our ability to detect features associated with proteins in that fraction, we complemented our data with a meta-analysis of studies reporting the detergent-insoluble proteins in various mouse models of aging and neurodegeneration. Strikingly, insoluble proteins from young and old mice are distinct in several features in our study and across the collected literature data. In younger mice, proteins are more likely to be disordered, part of membraneless organelles, and involved in RNA binding. These traits become less prominent with age, as an increased number of structured proteins enter the pellet fraction. This analysis suggests that age-related changes to proteome organization lead a group of proteins with specific features to become detergent-insoluble. Importantly, these features are not consistent with those associated with proteins driving membraneless organelle formation. We see no evidence in our system of a general increase of condensate proteins in the detergent-insoluble fraction with age.

Left Atrial Posterior Wall Isolation with Pulsed Field Ablation in Persistent Atrial Fibrillation.

BACKGROUND: Left atrial posterior wall isolation (LAPWI) may improve rhythm control in addition to pulmonary vein isolation (PVI) in persistent atrial fibrillation (persAF) patients undergoing catheter ablation (CA). However, LAPWI may be challenging when using thermal energy sources. OBJECTIVE: This study aimed to investigate the efficacy and safety of LAPWI performed by non-thermal pulsed field ablation (PFA) in CA for persAF. METHODS: Consecutive persAF patients from two German centers were prospectively enrolled. There were two study cohorts: (1) the LAPWI cohort, which included PFA-guided (re-)PVI with LAPWI for first-time and/or repeat ablation procedures; and (2) a comparative persAF cohort with a PFA PVI-only approach without LAPWI for first-time ablation within the same timeframe. Patients were followed up by routine Holter ECGs. RESULTS: In total, 79 persistent AF patients were included in the study: 59/79 patients were enrolled in the LAPWI cohort, including 16/59 index (27%) and 43/59 repeat ablation procedures (73%). Sixteen patients (16/79; 21%) were in the PVI-only cohort without LAPWI. Of the patients treated with LAPWI, procedure time and fluoroscopy time was 91 ± 30 min and 15 ± 7 min, respectively. The acute PVI rate was 100% in all first-time ablation patients (32 patients (16 PVI only, 16 PVI plus LAPWI), 196/196 PVs). Of the 43 re-do patients in the LAPWI cohort, re-PVI was necessary in 33% (14/43) of patients (27 PVs; 1.9 PV per-patient); in 67% (29/43), all PVs were isolated, and antral ablation of the PV ostia was performed in 48% (14/29). LAPWI was performed successfully in all 59 (100%) patients of the LAPWI cohort. Two minor complications occurred. No esophageal lesion was detected in the LAPWI cohort (n = 33/59 (56%) patients underwent endoscopy). After 354 ± 197 days of follow-up, freedom from atrial arrhythmias was 79.3% (95-CI: 62-95%) in the complete LAPWI cohort (n = 14/59 (24%) on AAD: class Ic n = 9, class III n = 5). There was no difference regarding acute procedural and clinical outcome compared to the PVI-only cohort. CONCLUSION: LAPWI guided by PFA is feasible and safe in patients undergoing CA for persAF and shows favorable outcomes. In the context of durable PVI, PFA-guided LAPWI may be an effective adjunctive treatment option.

Positional proteomics: is the technology ready to study clinical cohorts?

INTRODUCTION: Positional proteomics provides proteome-wide information on protein termini and their modifications, uniquely enabling unambiguous identification of site-specific, limited proteolysis. Such proteolytic cleavage irreversibly modifies protein sequences resulting in new proteoforms with distinct protease-generated neo-N and C-termini and altered localization and activity. Misregulated proteolysis is implicated in a wide variety of human diseases. Protein termini, therefore, constitute a huge, largely unexplored source of specific analytes that provides a deep view into the functional proteome and a treasure trove for biomarkers. AREAS COVERED: We briefly review principal approaches to define protein termini and discuss recent advances in method development. We further highlight the potential of positional proteomics to identify and trace specific proteoforms, with a focus on proteolytic processes altered in disease. Lastly, we discuss current challenges and potential for applying positional proteomics in biomarker and pre-clinical research. EXPERT OPINION: Recent developments in positional proteomics have provided significant advances in sensitivity and throughput. In-depth analysis of proteolytic processes in clinical cohorts thus appears feasible in the near future. We argue that this will provide insights into the functional state of the proteome and offer new opportunities to utilize proteolytic processes altered or targeted in disease as specific diagnostic, prognostic and companion biomarkers.

Ventricular arrhythmia burden in ICD patients during the second wave of the COVID-19 pandemic.

AIM: COVID-19 has been associated with cardiovascular complications including ventricular arrhythmias (VA) and an increased number of out-of-hospital cardiac arrests. Nevertheless, several authors described a decrease of VA burden in patients with an implantable defibrillator (ICD) during the first wave of the COVID-19 pandemic. The objective of this study was to determine if these observations could be transferred to later periods of the pandemic as well. METHODS: We retrospectively analyzed a total of 1674 patients with an ICD presenting in our outpatient clinic during the second wave of the COVID-19 pandemic and during a control period for the occurrence of VA requiring ICD interventions. RESULTS: Seven hundred ninety-five patients with an ICD had a device interrogation in our ambulatory clinic during the second wave of the COVID-19 pandemic compared to eight hundred seventy-nine patients in the control period. There was significant higher amount of adequate ICD therapies in the course of the COVID-19 period. Thirty-six patients (4.5%) received in total eighty-five appropriate ICD interventions during COVID-19, whereas only sixteen patients (1.8%) had sustained VA in the control period (p = 0.01). CONCLUSION: In contrast to the first wave of COVID-19, which was characterized by a decrease or least stable number of ICD therapies in several centers, we found a significant increase of VA in ICD patients during the second wave of COVID-19. Possible explanations for this observation include higher infectious rates, potential cardiac side effects of the vaccination as well as personal behavioral changes, or reduced utilization of medical services.

Mechanisms of Pathogenicity of Hypertrophic Cardiomyopathy-Associated Troponin T (TNNT2) Variant R278C+/- During Development.

Hypertrophic cardiomyopathy (HCM) is one of the most common heritable cardiovascular diseases and variants of TNNT2 (cardiac troponin T) are linked to increased risk of sudden cardiac arrest despite causing limited hypertrophy. In this study, a TNNT2 variant, R278C+/-, was generated in both human cardiac recombinant/reconstituted thin filaments (hcRTF) and human- induced pluripotent stem cells (hiPSCs) to investigate the mechanisms by which the R278C+/- variant affects cardiomyocytes at the proteomic and functional levels. The results of proteomics analysis showed a significant upregulation of markers of cardiac hypertrophy and remodeling in R278C+/- vs. the isogenic control. Functional measurements showed that R278C+/- variant enhances the myofilament sensitivity to Ca2+, increases the kinetics of contraction, and causes arrhythmia at frequencies >75 bpm. This study uniquely shows the profound impact of the TNNT2 R278C+/- variant on the cardiomyocyte proteomic profile, cardiac electrical and contractile function in the early stages of cardiac development.

Implementing precision oncology for sarcoma patients: the CCCLMUmolecular tumor board experience.

PURPOSE: Due to poor outcomes and limited treatment options, patients with advanced bone and soft tissue sarcomas (BS/STS) may undergo comprehensive molecular profiling of tumor samples to identify possible therapeutic targets. The aim of this study was to determine the impact of routine molecular profiling in the setting of a dedicated precision oncology program in patients with BS/STS in a German large-volume sarcoma center. METHODS: 92 BS/STS patients who received comprehensive genomic profiling (CGP) and were subsequently discussed in our molecular tumor board (MTB) between 2016 and 2022 were included. Patient records were retrospectively reviewed, and the clinical impact of NGS-related findings was analyzed. RESULTS: 89.1% of patients had received at least one treatment line before NGS testing. At least one molecular alteration was found in 71 patients (82.6%). The most common alterations were mutations in TP53 (23.3% of patients), followed by PIK3CA and MDM2 mutations (9.3% each). Druggable alterations were identified, and treatment recommended in 32 patients (37.2%). Of those patients with actionable alterations, ten patients (31.2%) received personalized treatment and six patients did benefit from molecular-based therapy in terms of a progression-free survival ratio (PFSr) > 1.3. CONCLUSION: Our single-center experience shows an increasing uptake of next-generation sequencing (NGS) and highlights current challenges of implementing precision oncology in the management of patients with BS/STS. A relevant number of patients were diagnosed with clinically actionable alterations. Our results highlight the potential benefit of NGS in patients with rare cancers and currently limited therapeutic options.

Adaptation of the Th-MYCN Mouse Model of Neuroblastoma for Evaluation of Disseminated Disease.

High-risk neuroblastoma remains a profound clinical challenge that requires eradication of neuroblastoma cells from a variety of organ sites, including bone marrow, liver, and CNS, to achieve a cure. While preclinical modeling is a powerful tool for the development of novel cancer therapies, the lack of widely available models of metastatic neuroblastoma represents a significant barrier to the development of effective treatment strategies. To address this need, we report a novel luciferase-expressing derivative of the widely used Th-MYCN mouse. While our model recapitulates the non-metastatic neuroblastoma development seen in the parental transgenic strain, transplantation of primary tumor cells from disease-bearing mice enables longitudinal monitoring of neuroblastoma growth at distinct sites in immune-deficient or immune-competent recipients. The transplanted tumors retain GD2 expression through many rounds of serial transplantation and are sensitive to GD2-targeted immune therapy. With more diverse tissue localization than is seen with human cell line-derived xenografts, this novel model for high-risk neuroblastoma could contribute to the optimization of immune-based treatments for this deadly disease.

The role of the communicated treatment rationale on treatment outcome: study protocol for a randomized controlled trial.

BACKGROUND: Placebo effects are a well-established phenomenon in the treatment of depression. However, the mechanism underlying these effects are not fully understood. Treatment expectations are considered one explanation for why placebos work. Treatment expectations are likely to be affected by clinician-patient interactions. This study aims to investigate the role of the communicated treatment rationale in modulating treatment expectations and its effects on the treatment outcomes of a pharmacological and a psychological active placebo intervention for depression. In this study, treatment expectations are modulated by presenting illness models that are either congruent or incongruent with the treatment intervention that follows. METHODS: This 2 × 2 randomized controlled trial will involve patients with major depression. Participants will either receive a biological or a psychological illness model from a clinician. Following this, they are randomly assigned to receive either a pharmacological or a psychological active placebo intervention. The illness model and the treatment are either congruent or incongruent with each other, resulting in four groups. In addition, a natural course control group will be included. DISCUSSION: This study will provide insights into the mechanism of expectation modulation in active placebo treatments for major depression. The results may provide insights for clinicians to improve their communication with patients by focusing on treatment expectations. By identifying the factors that contribute to placebo effects, this study has the potential to improve the effectiveness of existing depression treatments and reduce the burden of this highly prevalent mental health condition. TRIAL REGISTRATION: This trial has been registered prospectively at ClinicalTrials.gov under the identifier: NCT04719663. Registered on January 22, 2021.

Predictors for major in-hospital complications after catheter ablation of ventricular arrhythmias: validation and modification of the Risk in Ventricular Ablation (RIVA) Score.

OBJECTIVE AND BACKGROUND: Catheter-based treatment of patients with ventricular arrhythmias (VA) reduces VA and mortality in selected patients. With regard to potential risks of catheter ablation, a benefit-risk assessment should be carried out. This can be performed with risk scores such as the recently published "Risk in Ventricular Ablation (RIVA) Score". We sought to validate this score and to test for possible additional predictors in a large database of VT ablations. METHODS AND RESULTS: We analyzed 1964 catheter ablations for VA in patients with (1069; 54.4%) and without (893, 45.6%) structural heart disease (SHD) and observed an overall major adverse event rate of 4.0% with an in-hospital mortality of 1.3% with significantly less complications occurring in patients without structural heart disease (6.5% vs. 1.1%; p ≤ 0.01). The RIVA Score demonstrated to be a valid predictive tool for major in-hospital complications (OR 1.18; 95% CI 1.12, 1.25; p ≤ 0.001). NYHA Class ≥ III (OR 2.5; 95% CI 1.5, 4.2; p < 0.001) and age (OR 1.04; 95% CI 1.02, 1.07; p ≤ 0.001) proved to be additional predictive parameters. Hence, a modified RIVA Score (mRIVA) model was analyzed with a subset of established predictors (SHD, eGFR, epicardial puncture) as well as new predictive parameters (age, NYHA Class ≥ III), that achieved a higher predictive value for major complications compared with the model based on all RIVA variables. CONCLUSION: Adding age and functional heart failure status (NYHA class) as simple clinical parameters to the recently published RIVA Score increases the predictive value for ablation-associated complications in a large VT ablations registry.

RNA Polymerase II transcription independent of TBP in murine embryonic stem cells.

Transcription by RNA Polymerase II (Pol II) is initiated by the hierarchical assembly of the pre-initiation complex onto promoter DNA. Decades of research have shown that the TATA-box binding protein (TBP) is essential for Pol II loading and initiation. Here, we report instead that acute depletion of TBP in mouse embryonic stem cells has no global effect on ongoing Pol II transcription. In contrast, acute TBP depletion severely impairs RNA Polymerase III initiation. Furthermore, Pol II transcriptional induction occurs normally upon TBP depletion. This TBP-independent transcription mechanism is not due to a functional redundancy with the TBP paralog TRF2, though TRF2 also binds to promoters of transcribed genes. Rather, we show that the TFIID complex can form and, despite having reduced TAF4 and TFIIA binding when TBP is depleted, the Pol II machinery is sufficiently robust in sustaining TBP-independent transcription.

ASAP─Automated Sonication-Free Acid-Assisted Proteomes─from Cells and FFPE Tissues.

Formalin-fixed, paraffin-embedded (FFPE) tissues are an invaluable resource for retrospective studies, but protein extraction and subsequent sample processing steps have been shown to be challenging for mass spectrometry (MS) analysis. Streamlined high-throughput sample preparation workflows are essential for efficient peptide extraction from complex clinical specimens such as fresh frozen tissues or FFPE. Overall, proteome analysis has gained significant improvements in the instrumentation, acquisition methods, sample preparation workflows, and analysis pipelines, yet even the most recent FFPE workflows remain complex and are not readily scalable. Here, we present an optimized workflow for automated sonication-free acid-assisted proteome (ASAP) extraction from FFPE sections. ASAP enables efficient protein extraction from FFPE specimens, achieving similar proteome coverage as established methods using expensive sonicators, resulting in reduced sample processing time. The broad applicability of ASAP on archived pediatric tumor FFPE specimens resulted in high-quality data with increased proteome coverage and quantitative reproducibility. Our study demonstrates the practicality and superiority of the ASAP workflow as a streamlined, time- and cost-effective pipeline for high-throughput FFPE proteomics of clinical specimens.