Publications by authors named "Jan Loewe"

Extracellular volume (ECV) by cardiovascular magnetic resonance (CMR) imaging is associated with disease burden and clinical outcomes. Recent studies in patients with valvular heart disease (VHD) have suggested that the indexed total ECV (iECV) = ECVx(LV/1.05)/body surface area may supersede ECV in terms of prognostication.

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Purpose: The visualization of peripheral in-stent restenosis using energy-integrating detector CT is challenging due to deficient spatial resolution and artifact formation. This study compares the first clinically available photon-counting detector CT to third-generation dual-source energy-integrating detector CT.

Materials And Methods: Nylon cylinders with central bores (4 mm, 2 mm), mimicking 75% and 95% stenoses, were placed inside seven different 8-mm diameter stents and filled with diluted contrast medium.

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Purpose: This follow-up study was designed as a reopen of the completed Freeway Stent Study and collected mortality and clinical outcome data for at least 5 years after enrollment to evaluate long-term patient safety and treatment efficacy. The primary study enrolled 204 patients with stenosis or occlusion in the superficial femoral artery and proximal popliteal artery. Patients were randomized to primary nitinol stenting followed by standard PTA or primary nitinol stenting followed by FREEWAY™ paclitaxel-eluting balloon PTA.

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Article Synopsis
  • Cardiac amyloidosis (CA) presents specific changes in ECG that are not fully understood, leading researchers to investigate the relationship between amyloid burden and ECG parameters.
  • A study involving 105 CA patients found a negative correlation between total QRS voltage and amyloid levels, indicating that increased amyloid deposits result in lower QRS voltages.
  • Despite these findings, baseline ECG metrics like QRS voltage did not correlate with worse patient outcomes, suggesting that while amyloid burden affects ECG readings, it does not predict survival.
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Feature importance methods promise to provide a ranking of features according to importance for a given classification task. A wide range of methods exist but their rankings often disagree and they are inherently difficult to evaluate due to a lack of ground truth beyond synthetic datasets. In this work, we put feature importance methods to the test on real-world data in the domain of cardiology, where we try to distinguish three specific pathologies from healthy subjects based on ECG features comparing to features used in cardiologists' decision rules as ground truth.

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Run-and-tumble processes successfully model several living systems. While studies have typically focused on particles with isotropic tumbles, recent examples exhibit "tumble-turns", in which particles undergo 90° tumbles and so possess explicitly anisotropic dynamics. We study the consequences of such tumble-turn anisotropicity at both short and long-time scales.

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The human heart is subject to highly variable amounts of strain during day-to-day activities and needs to adapt to a wide range of physiological demands. This adaptation is driven by an autoregulatory loop that includes both electrical and the mechanical components. In particular, mechanical forces are known to feed back into the cardiac electrophysiology system, which can result in pro- and anti-arrhythmic effects.

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  • * In a study involving 18,796 participants, the SSD-12 displayed characteristics of both a 1-factor and a 3-factor structure, with high internal consistency values indicating reliability.
  • * Results showed that higher SSD-12 scores are linked to worse mental health outcomes, like increased depressive symptoms and a greater likelihood of seeking medical help for symptoms attributed to mental health issues rather than physical causes.
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Protective immune responses to many pathogens depend on the development of high-affinity antibody-producing plasma cells (PC) in germinal centers (GCs). Transgenic models suggest that there is a stringent affinity-based barrier to PC development. Whether a similar high-affinity barrier regulates PC development under physiologic circumstances and the nature of the PC fate decision has not been defined precisely.

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Introduction: Metronomic chemotherapy (MCT) is increasingly used in oncology due to its favorable therapeutic index. There is still a lack of evidence for MCT in metastatic breast cancer (MBC). In this retrospective unicenter study, we demonstrated real-word data on MCT in MBC.

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In metastatic breast cancer (MBC), mutations, activating the phosphatidylinositol 3-kinase (PI3K) signaling pathway seem to be associated with chemotherapy resistance and poor outcome. Inhibition of the PI3K signaling pathway may lead to sensitization and prevention of the development of resistance to cytotoxic drugs. The present study aimed to investigate the anti-tumor activity of low-dose vinorelbine (VRL) combined with alpelisib, an α-selective PI3K inhibitor and degrader, in breast cancer (BC) cells.

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Background: Progressive atrial fibrotic remodeling has been reported to be associated with atrial cardiomyopathy (ACM) and the transition from paroxysmal to persistent atrial fibrillation (AF). We sought to identify the anatomical/structural and electrophysiological factors involved in atrial remodeling that promote AF persistency.

Methods: Consecutive patients with paroxysmal ( = 134) or persistent ( = 136) AF who presented for their first AF ablation procedure were included.

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Purpose: Despite the growing understanding of the carcinogenesis of pelvic high-grade serous carcinoma (HGSC) of the ovary and peritoneum and its precursor lesion serous tubal intraepithelial carcinoma (STIC), evidence-based proven recommendations on the clinical management of patients with STIC are lacking so far.

Methods: A questionnaire containing 21 questions was developed to explore the clinical experience with patients with the diagnosis of STICs and the diagnostic, surgical and histopathological approaches in Germany. Overall, 540 clinical heads of department in all German gynaecological centres were asked to participate.

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Purpose: In penetrating aortic ulcers (PAUs), limited data support tubular thoracic endovascular aortic repair (TEVAR) as a viable treatment option. For treatment of more proximal PAUs, hybrid approaches and-more recently-scalloped TEVAR (scTEVAR) have been advocated. Outcomes of scTEVAR specifically for PAUs have not yet been reported.

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The 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 , a key regulator of the heart rate dependent adaptation of the cardiac action potential duration (APD).

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Purpose: Atrial fibrillation is one of the most frequent cardiac arrhythmias in the industrialized world and ablation therapy is the method of choice for many patients. However, ablation scars alter the electrophysiological activation and the mechanical behavior of the affected atria. Different ablation strategies with the aim to terminate atrial fibrillation and prevent its recurrence exist but their impact on the performance of the heart is often neglected.

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In order to classify and analyze the parameters of upper body posture in clinical or physiotherapeutic settings, a baseline in the form of standard values with special regard to age, sex and BMI is required. Thus, subjectively healthy men and women aged 21-60 years were measured in this project. The postural parameters of 800 symptom-free male (n = 397) and female (n = 407) volunteers aged 21-60 years (Ø♀: 39.

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Antibody responses are characterized by increasing affinity and diversity over time. Affinity maturation occurs in germinal centers by a mechanism that involves repeated cycles of somatic mutation and selection. How antibody responses diversify while also undergoing affinity maturation is not as well understood.

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Approximating the fast dynamics of depolarization waves in the human heart described by the monodomain model is numerically challenging. Splitting methods for the PDE-ODE coupling enable the computation with very fine space and time discretizations. Here, we compare different splitting approaches regarding convergence, accuracy, and efficiency.

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Article Synopsis
  • Feedback inhibition of humoral immunity by antibodies has been observed since 1909, with studies showing that antibodies can either enhance or inhibit immune responses depending on the context.
  • A study focused on individuals who received two high-affinity anti-SARS-CoV-2 monoclonal antibodies and later two mRNA vaccine doses revealed that while their antibody production was slightly lower, their memory B cells predominantly expressed low-affinity IgM antibodies with few mutations and altered binding specificity.
  • The research indicates that existing high-affinity antibodies can affect the immune response by lowering the activation threshold for B cells and masking their target sites, which may help explain changes in memory antibody profiles after booster vaccinations.
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Objective: The bidomain model and the finite element method are an established standard to mathematically describe cardiac electrophysiology, but are both suboptimal choices for fast and large-scale simulations due to high computational costs. We investigate to what extent simplified approaches for propagation models (monodomain, reaction-Eikonal and Eikonal) and forward calculation (boundary element and infinite volume conductor) deliver markedly accelerated, yet physiologically accurate simulation results in atrial electrophysiology.

Methods: We compared action potential durations, local activation times (LATs), and electrocardiograms (ECGs) for sinus rhythm simulations on healthy and fibrotically infiltrated atrial models.

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