30 research outputs found

    Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

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    The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

    Annäherung an ein Rollen-, Aufgaben- und Kompetenzprofil von SP-Trainer:innen

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    Es ist zwar eine Weile her, aber als wir noch Kinder waren, haben wir nicht unseren Eltern stolz verkündet, dass wir, wenn wir mal gross sind, unbedingt SP-Trainer:in werden wollen. Wäre auch nicht so wahrscheinlich gewesen, weil es das Berufsbild der „SP-Trainer:in“ noch gar nicht gab. Manche Leute stellen auch heute noch infrage, ob es ein solches Berufsbild überhaupt gibt. Leider ist vielen Personen im Hochschulumfeld noch nicht klar, was SP-Trainer:innen machen. Nämlich so viel mehr, als nur Fälle mit SP zusammen zu lesen! Wir schreiben und revidieren Fälle, trainieren authentische und standardisierte Rollendarstellung ein. Wir vermitteln Kommunikationsmodelle und leiten zu sinnhaftem Feedback an. Wir managen die SP und das SP-Programm, erläutern immer wieder Dritten, was SP eigentlich sind und wann man sie einsetzen kann und wann nicht und vieles mehr. Wenn wir in uns gehen, mögen wir uns manchmal selbst fragen, wo eigentlich die Aufgaben und Grenzen unseres professionellen Handelns als SP-Trainer:in liegen. Als Unterarbeitsgruppe des SP-Ausschusses haben wir uns genau dieser Frage gewidmet und begonnen, die professionellen Rollen, Aufgabengebiete und Kompetenzen von SP-Trainer:innen zu formulieren und uns einem gemeinsamen Modell dieser Tätigkeit zu nähern. Wir freuen uns, zusammen mit euch in unserem Präsymposium an diesem Thema zu arbeiten, euch zu präsentieren, wo wir gerade stehen und das Modell mit euch gemeinsam weiter voranzubringen

    Inclusion Body Bead Size in E. coli Controlled by Physiological Feeding

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    The Gram-negative bacterium E. coli is the host of choice for producing a multitude of recombinant proteins relevant in the pharmaceutical industry. Generally, cultivation is easy, media are cheap, and a high product titer can be obtained. However, harsh induction procedures combined with the usage of IPTG (isopropyl β-d-1 thiogalactopyranoside) as an inducer are often believed to cause stress reactions, leading to intracellular protein aggregates, which are so known as so-called inclusion bodies (IBs). Downstream applications in bacterial processes cause the bottleneck in overall process performance, as bacteria lack many post-translational modifications, resulting in time and cost-intensive approaches. Especially purification of inclusion bodies is notoriously known for its long processing times and low yields. In this contribution, we present screening strategies for determination of inclusion body bead size in an E. coli-based bioprocess producing exclusively inclusion bodies. Size can be seen as a critical quality attribute (CQA), as changes in inclusion body behavior have a major effect on subsequent downstream processing. A model-based approach was used, aiming to trigger a distinct inclusion body size: Physiological feeding control, using qs,C as a critical process parameter, has a high impact on inclusion body size and could be modelled using a hyperbolic saturation mechanism calculated in form of a cumulated substrate uptake rate. Within this model, the sugar uptake rate of the cells, in the form of the cumulated sugar uptake-value, was simulated and considered being a key performance indicator for determination of the desired size. We want to highlight that the usage of the mentioned screening strategy in combination with a model-based approach will allow tuning of the process towards a certain inclusion body size using a qs based control only. Optimized inclusion body size at the time-point of harvest should stabilize downstream processing and, therefore, increase the overall time-space yield. Furthermore, production of distinct inclusion body size may be interesting for application as a biocatalyst and nanoparticulate material

    Custom made inclusion bodies: impact of classical process parameters and physiological parameters on inclusion body quality attributes

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    Abstract Background The bacterium E. coli is a major host for recombinant protein production of non-glycosylated products. Depending on the expression strategy, the recombinant protein can be located intracellularly. In many cases the formation of inclusion bodies (IBs), protein aggregates inside of the cytoplasm of the cell, is favored in order to achieve high productivities and to cope with toxic products. However, subsequent downstream processing, including homogenization of the cells, centrifugation or solubilization of the IBs, is prone to variable process performance or can be characterized by low extraction yields as published elsewhere. It is hypothesized that variations in IB quality attributes (QA) are responsible for those effects and that such attributes can be controlled by upstream process conditions. This contribution is aimed at analyzing how standard process parameters, such as pH and temperature (T) as well as different controlled levels of physiological parameters, such as specific substrate uptake rates, can vary IB quality attributes. Results Classical process parameters like pH and T influence the expression of analyzed IB. The effect on the three QAs titer, size and purity could be successfully revealed. The developed data driven model showed that low temperatures and low pH are favorable for the expression of the two tested industrially relevant proteins. Based on this knowledge, physiological control using specific substrate feeding rate (of glucose) qs,Glu is altered and the impact is tested for one protein. Conclusions Time dependent monitoring of IB QA—titer, purity, IB bead size—showed a dependence on classical process parameters pH and temperature. These findings are confirmed using a second industrially relevant strain. Optimized process conditions for pH and temperature were used to determine dependence on the physiological parameters, the specific substrate uptake rate (qs,Glu). Higher qs,Glu were shown to have a strong influence on the analyzed IB QAs and drastically increase the titer and purity in early time stages. We therefore present a novel approach to modulate—time dependently—quality attributes in upstream processing to enable robust downstream processing
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