Publications by authors named "Martin Fiedler"

Background: Serological tests are a powerful tool in the monitoring of infectious diseases and the detection of host immunity. However, manufacturers often provide diagnostic accuracy data generated through biased studies, and the performance in clinical practice is essentially unclear.

Objectives: We aimed to determine the diagnostic accuracy of various serological testing strategies for (a) identification of patients with previous coronavirus disease-2019 (COVID-19) and (b) prediction of neutralizing antibodies against SARS-CoV-2 in real-life clinical settings.

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Background: Serological immunoassays that can identify protective immunity against SARS-CoV-2 are needed to adapt quarantine measures, assess vaccination responses, and evaluate donor plasma. To date, however, the utility of such immunoassays remains unclear. In a mixed-design evaluation study, we compared the diagnostic accuracy of serological immunoassays that are based on various SARS-CoV-2 proteins and assessed the neutralizing activity of antibodies in patient sera.

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In contrast to the "Warburg effect" or aerobic glycolysis earlier generalized as a phenomenon in cancer cells, more and more recent evidence indicates that functional mitochondria are pivotal for ensuring the energy supply of cancer cells. Here, we report that cancer cells with reduced autophagy-related protein 12 (ATG12) expression undergo an oncotic cell death, a phenotype distinct from that seen in ATG5-deficient cells described before. In addition, using untargeted metabolomics with ATG12-deficient cancer cells, we observed a global reduction in cellular bioenergetic pathways, such as β-oxidation (FAO), glycolysis, and tricarboxylic acid cycle activity, as well as a decrease in mitochondrial respiration as monitored with Seahorse experiments.

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Background: Although the complexity and length of treatment is connected to the newborn's maturity and birth weight, most case-mix grouping schemes classify newborns by birth weight alone. The objective of this study was to determine whether the definition of thresholds based on a changepoint analysis of variability of birth weight and gestational age contributes to a more homogenous classification.

Methods: This retrospective observational study was conducted at a Tertiary Care Center with Level III Neonatal Intensive Care and included neonate cases from 2016 through 2018.

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Background:  The use of short and uniform centrifugation schemes contributes significantly to the successful automation of laboratory procedures. It is however unclear if this is applicable to the hemostasis laboratory.

Objectives:  This article assesses the accuracy of measurements obtained with a rapid, high-speed centrifugation scheme in a large set of hemostasis tests, covering the full spectrum of values obtained in clinical practice, and using meaningful statistical measures.

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Anaemia affects quality of life and radiographic outcome in rheumatoid arthritis (RA). In a cross-sectional study with 779 patients, we assessed the prognostic potential of the major haematopoietic regulators, hepcidin and erythropoietin, comparing their serum concentrations with respect to different anaemia types, inflammatory activity, anti-cytokine-specific treatment effects and iron deficiency (ID) indices. The results showed that clinical disease activity was more closely associated with haemoglobin levels than with anti-tumour necrosis factor-alpha or interleukin 6 receptor effects.

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Given the vast phenotypic and genetic heterogeneity of acute and chronic myeloid malignancies, hematologists have eagerly awaited the introduction of next-generation sequencing (NGS) into the routine diagnostic armamentarium to enable a more differentiated disease classification, risk stratification, and improved therapeutic decisions. At present, an increasing number of hematologic laboratories are in the process of integrating NGS procedures into the diagnostic algorithms of patients with acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and myeloproliferative neoplasms (MPNs). Inevitably accompanying such developments, physicians and molecular biologists are facing unexpected challenges regarding the interpretation and implementation of molecular genetic results derived from NGS in myeloid malignancies.

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Background: Accelerated bone loss occurs rapidly following renal transplantation due to intensive immunosuppression and persistent hyperparathyroidism. In renal transplant recipients (RTRs) due to the hyperparathyroidism the non-dominant forearm is often utilized as a peripheral measurement site for dual-energy x-ray absorptiometry (DXA) measurements. The forearm is also the site of previous created distal arteriovenous fistulas (AVF).

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Owing to the introduction of next-generation sequencing (NGS) new challenges for diagnostic algorithms and the interpretation of the results for therapeutic decision making in hemato-oncology have arisen. Recurrent somatic mutations crossing the borders between different hematological entities and solid neoplasms have been detected. In analogy to mutant TP53, the same mutation type may occur in myeloid, B- or T-lymphatic malignancies or solid neoplasms.

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Diagnostics of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) have recently been experiencing extensive modifications regarding the incorporation of next-generation sequencing (NGS) strategies into established diagnostic algorithms, classification and risk stratification systems, and minimal residual disease (MRD) detection. Considering the increasing arsenal of targeted therapies (e.g.

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Background: Cardiac troponin T (cTnT) is elevated after coronary artery bypass grafting surgery. The aim of this study was to determine the association between cTnT elevations between 6 and 12 hours after coronary artery bypass grafting and in-hospital outcome.

Methods And Results: We prospectively studied 1722 patients undergoing isolated coronary artery bypass grafting.

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Introduction: The immunosuppressive therapy with everolimus (ERL) after heart transplantation is characterized by a narrow therapeutic window and a substantial variability in dose requirement. Factors explaining this variability are largely unknown.

Objectives: Our aim was to evaluate factors affecting ERL metabolism and to identify novel metabolites associated with the individual ERL dose requirement to elucidate mechanisms underlying ERL dose response variability.

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Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor survival. There is an urgent need to better diagnose and monitor IPF patients as new treatments which slow down disease progression are now available. Exhaled breath condensate (EBC) is easily and non-invasively collected, but analysis of potential biomarkers is difficult due to low concentrations and methodological limitations.

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Restless legs syndrome (RLS) is a common multifactorial disease. Some genetic risk factors have been identified. RLS susceptibility also has been related to iron.

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Background: The IABP-SHOCK-trial was a morbidity-based randomized controlled trial in patients with infarction-related cardiogenic shock (CS), which used the change of the quantified degree of multiorgan failure as determined by APACHE II score over a 4-day period as primary outcome measure. The prospective hypothesis was that adding IABP therapy to "standard care" would improve CS-triggered multi organ dysfunction syndrome (MODS). The primary endpoint showed no difference between conventionally managed cardiogenic shock patients and those with IABP support.

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Objective: Long-term dietary intervention frequently induces a rapid weight decline followed by weight stabilization/regain. Here, we sought to identify adipokine biomarkers that may reflect continued beneficial effects of dieting despite partial weight regain.

Research Design And Methods: We analyzed the dynamics of fasting serum levels of 12 traditional metabolic biomarkers and novel adipokines among 322 participants in the 2-year Dietary Intervention Randomized Controlled Trial (DIRECT) of low-fat, Mediterranean, or low-carbohydrate diets for weight loss.

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The aim of the present study was to investigate the effect of exercise on angiogenesis during bone defect healing in mice. We evaluated angiogenesis during cranial bone defect healing by intravital fluorescence microscopy (IVM) at days 0-21. To characterize the type of bone repair, we performed additional histomorphometric analyses at days 3-15.

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The level of body iron storage and the erythropoietic need for iron are indicated by the serum levels of ferritin and soluble transferrin receptor (sTfR), respectively. A meta-analysis of five genome-wide association studies on sTfR and ferritin revealed novel association to the PCSK7 and TMPRSS6 loci for sTfR and the HFE locus for both parameters. The PCSK7 association was the most significant (rs236918, P = 1.

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Aim: CD4(+) T cells contribute to disturbances of liver microcirculation after warm ischemia/reperfusion (I/R). The aim of this study was to investigate a possible protective role of FTY720 (Sphingosine-1 phosphate receptor agonist) in this setting.

Material And Methods: In an in vivo model (42 Wistar rats), ischemia of the left liver lobe was induced for 90 min under anesthesia with xylazine/ketanest.

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Background: Mice have become of increasing interest as experimental model for fracture studies. Due to their small size, most studies use simple pins for fracture stabilization, although insufficient rigidity of fixation critically affects fracture healing. Herein, we studied whether longitudinal fracture compression by an intramedullary screw represents a standardized, stable osteosynthesis technique in mice, and whether it may accelerate fracture healing.

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Objectives: Recent evidence emerges dendritic cells (DCs) as pharmacological targets of immunosuppressive drugs. Therefore, in this study we monitored DCs in peripheral blood to compare the effects of calcineurin inhibitors (CNI: cyclosporine, tacrolimus) and mammalian target of rapamycin inhibitors (sirolimus, SRL, everolimus, ERL) basis-immunosuppressive therapies in human heart transplanted (HTx) recipients.

Methods: We compared HTx recipients which were converted from either CNI to ERL (severe renal dysfunction, n=8), or from SRL to ERL (approval of ERL for HTx, n=8) with 20 healthy human controls.

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