Anesthesiological Care of MitraClip-Procedures - Description of a university actual state

Einleitung: Nach der Aortenklappenstenose ist die Mitralklappeninsuffizienz (MI) das zweithäufigste Klappenvitium in den westlichen Nationen. Als Alternative zur kardiochi-rurgischen Sanierung hat sich in den letzten Jahren die Möglichkeit des MitraClippings (MC) als perkutane Therapieform bei älteren, multimorbiden Patient*innen etabliert. Die Narkose erfolgt in den meisten Zentren nach kardiochirurgischem Standard mit erweiter-tem hämodynamischem Monitoring, da bisher noch keine individualisierte anästhesiolo-gische Versorgung beschrieben ist. Das Ziel dieser Arbeit war die Untersuchung der Sicherheit und Effektivität des Verfah-rens und des anästhesiologischen Vorgehens an der Charité-Universitätsmedizin Berlin. Methodik: In dieser retrospektiven Untersuchung wurden elektronische Daten von Pati-ent*innen, die sich im Zeitraum vom 01.11.2011 bis zum 30.09.2017 am Campus Mitte einer MC-Behandlung unterzogen, analysiert. Hierzu wurden demographische und mor-phometrische Parameter, echokardiografische Werte zur Evaluation der MI vor und nach Intervention, die Krankenhaussterblichkeit, periprozedurale Komplikationen sowie das anästhesiologische Management erhoben. Für eine differenzierte Betrachtung des peri-interventionellen Katecholaminbedarfes wurde die Kohorte anhand der linksventrikulären Ejektionsfraktion (LVEF) in 3 Gruppen unterteilt: Patient*innen mit erhaltener (> 50 %), mittelgradig reduzierter (40-49 %) sowie hochgradig reduzierter (< 40 %) LVEF. Ergebnisse: 156 Patient*innen wurden untersucht: 41 (26,3 %) mit erhaltener, 35 (22,4 %) mit mittelgradig reduzierter und 80 (51,3 %) mit hochgradig reduzierter LVEF. Das mediane Alter lag bei 77 Jahren, 51 (32,7 %) waren Frauen. Bei 134 (86 %) Patient*innen konnte eine Reduktion der MI erreicht werden. Die Krankenhausmortalität lag bei 4,5 %. Die Narkose erfolgte als totalintravenöse Anästhesie mit druckkontrollierter Beatmung. Patient*innen mit hochgradig reduzierter LVEF zeigten peri-interventionell einen erhöh-ten Katecholaminbedarf im Vergleich zu Patient*innen mit erhaltener LVEF. Eine Norad-renalin Therapie 24 Stunden nach Intervention war bei Patient*innen mit hochgradig re-duzierter LVEF [32 von 80 Patient*innen (40 %)] signifikant häufiger notwendig als bei Patient*innen mit erhaltener LVEF [6 von 41 Patient*innen (14,6 %)] (p=0,013). Beim Adrenalin zeigte sich ein erhöhter Bedarf sowohl intraoperativ (LVEF 50 %: 19,5 % der Patient*innen) (p = 0,039) als auch 24 Stun-den postoperativ (p = 0,011). Diskussion: Die vorliegende Arbeit zeigt, dass das MC-Verfahren sicher und effizient an der Charité-Universitätsmedizin Berlin durchgeführt wird. Patient*innen mit hochgradig eingeschränkter LVEF benötigten hierbei peri-interventionell häufiger Katecholamine im Vergleich zu Patient*innen mit erhaltener LVEF. In diesem Kontext könnte zukünftig ein abgestuftes Monitoring-/Therapiekonzept in Anlehnung an die LVEF durchgeführt werden.Introduction: Mitral valve regurgitation is the second most frequent valvular defect in the western society, following aortic valve stenosis. In the last couple of years, the percuta-neous MitraClip (MC) procedure has emerged as a viable alternative to cardiac surgery, especially for older multimorbid patients with high surgical risk. Because there is no indi-vidualized anesthesia management for MC, anesthesia is most often maintained by using general anesthesia following the cardiac surgery standards with an extended cardiovas-cular monitoring. The aim of this work was to examine the procedure’s safety and efficiency as well as the anesthesia management at the Charité-Universitätsmedizin Berlin. Methods: Electronic data was collected and analyzed for every patient receiving MC be-tween 01.11.2011 and 30.09.2017 at Campus Mitte. Demographic and morphometric in-formation, echocardiographic values evaluating mitral regurgitation before and after the intervention, in-hospital mortality, periprocedural complications as well as the anesthesi-ologic management were examined. To compare the need of catecholamines during the procedure and afterwards the population was divided into three different groups depend-ing on their left ventricular ejection fraction (LVEF): patients with preserved (> 50 %), mildly reduced (40-49 %) and reduced (< 40 %) LVEF. Results: 156 patients were examined: 41 (26,3 %) with preserved, 35 (22,4 %) with mildly reduced and 80 (51,3 %) with reduced LVEF. The median age was 77 years and 51 (32,7 %) were females. We could reduce the mitral regurgitation in 134 (86 %) cases after MC. The overall in-hospital mortality was about 4,5 %. Anesthesia was performed by using total intravenous anesthesia with pressure-controlled ventilation. Patients with reduced LVEF needed catecholamines more often during and after the procedure. The noradren-aline usage 24 hours after intervention was significantly higher in patients with reduced LVEF [32 of 80 patients (40 %)] in comparison to those with a preserved one [6 von 41 patients (14,6 %)] (p=0,013). The adrenaline usage was significantly higher both in-traoperative (LVEF 50 %: 19,5 % patients) (p = 0,039) and 24 hours after intervention (p = 0,011). Discussion: This paper shows that the percutaneous MC-procedure can be performed safe and efficient at the Charité-Universitätsmedizin Berlin. Patients with reduced LVEF needed catecholamines more frequently during and after the procedure in comparison to patients with preserved LVEF. Therefore, a reduced monitoring/therapeutic concept could be used in the future based on the LVEF

a comparative assessment

Background The analysis of differential splicing (DS) is crucial for understanding physiological processes in cells and organs. In particular, aberrant transcripts are known to be involved in various diseases including cancer. A widely used technique for studying DS are exon arrays. Over the last decade a variety of algorithms for the detection of DS events from exon arrays has been developed. However, no comprehensive, comparative evaluation including sensitivity to the most important data features has been conducted so far. To this end, we created multiple data sets based on simulated data to assess strengths and weaknesses of seven published methods as well as a newly developed method, KLAS. Additionally, we evaluated all methods on two cancer data sets that comprised RT-PCR validated results. Results Our studies indicated ARH as the most robust methods when integrating the results over all scenarios and data sets. Nevertheless, special cases or requirements favor other methods. While FIRMA was highly sensitive according to experimental data, SplicingCompass, MIDAS and ANOSVA showed high specificity throughout the scenarios. On experimental data ARH, FIRMA, MIDAS, and KLAS performed best. Conclusions Each method shows different characteristics regarding sensitivity, specificity, interference to certain data settings and robustness over multiple data sets. While some methods can be considered as generally good choices over all data sets and scenarios, other methods show heterogeneous prediction quality on the different data sets. The adequate method has to be chosen carefully and with a defined study aim in mind

Computational Approaches to Examine Cellular Signalling Networks

Complex biological systems can only be analysed by utilizing computational and mathematical methods. They are essential for studying the interactions between the components of biological systems and generating an understanding how these interactions give rise to biological functions and mechanisms of cellular signalling networks. In this work, I provide three examples on how the analysis of single cell data derived from live-cell time-lapse microscopy of fluorescent reporter systems benefits from the use of several approaches that originate from computer sciences. The analysis of single cell data faces several challenges ranging from extracting single cell time series from the raw imaging data, identifying signalling classes to the identification of distinct patterns in single cell trajectories. Several methods were introduced in the course of this work to handle the experimental data appropriately. For the extraction of single cell time series, a novel method to track cells in the imaging data based on Coherent Point Drift was introduced. The tracking benefits from the features of the Coherent Point Drift method that correspond to cellular motility patterns. The motion coherence constrain of the Coherent Point Drift mimics the observation that cells do not move independently; they are embedded in a neighbourhood that constrains their freedom of movement. The Dynamic Time Warping framework was established as a useful approach to tackle several issues in the analysis of biological data. The opportunity to quantify the similarity of dynamics granted a new view on single cell data. While calculating the optimal alignment between two single cell trajectories their similarity can be quantified. Dynamic Time Warping was modified so that it constrains the flexibility of the alignment making the alignment more biological relevant. Based on Dynamic Time Warping estimated similarities among individual signalling dynamics distinct signalling classes could be identified in the datasets analysed. Dynamic Time Warping was as well utilized for multivariate time series. This allowed the comparison of single cells while taking the dependence of dynamics of several signalling components within a pathway into account. This gives a new way on the comparison of pathway activity among individual cells. Different signalling pathways exhibit different signalling dynamics. Therefore, two feature detection methods were proposed that aim to quantify signalling dynamics from different angles. The Dynamic Time Warping framework was used to develop a feature detection method that identifies patterns in the time series flexible in the time domain and independent of the scaling. If dynamics lack repetitive patterns dynamics have to be quantified in a different way. Therefore, to identify global dynamics a supervised learning method was developed that reduces the dimensionality of the time series data and identifies fundamental dynamics that compose the observed individual dynamics. To understand how cells, encode the extracellular input and transmit its information to elicit appropriate responses, quantitative time-resolved measurements of pathway activation at the single-cell level was acquired for all three scenarios. The application of the introduced set of tools provided new insight into fundamental biological questions. On the level of the raw imaging data the cell tracking step does only differ slightly between the three biological examples. On the single cell level the three signalling pathways studied exhibit different dynamics and demand therefore different requirements on the analysis. The TGFb pathway is a multi-functional signalling system regulating cellular processes ranging from proliferation and migration to differentiation and cell death. Alterations in the cellular response to TGFb are involved in severe human diseases. It was revealed that the response to a given dose of TGFb is determined cell specifically by the levels of defined signalling proteins and that the observed heterogeneity in signalling protein expression leads to decomposition of cells into classes with qualitatively distinct signalling dynamic. How the dynamics differ among the signalling classes could be quantified using the supervised learning approach. Studies have shown the beneficial effects of hyperthermic treatment during radiation- or chemotherapy of cancers. I aimed to understand how p53 dynamics after genotoxic stress are modulated by temperature across a physiological relevant range. In the range of 33°C to 39°C, pulsatile p53 accumulation dynamics are modulated in frequency. Above 40°C, a temperature that corresponds to mild hyperthermia in the clinical setting, a reversible phase transition towards sustained hyperaccumulation was observed. This disrupts the canonical p53 response to DNA double strand breaks. Above 40°C mild hyperthermia alone was sufficient to induce a p53 response. The view onto the p53 signalling was extended by simultaneously measurement of an additional pathway component. p21 as an inhibitor of cyclin-dependent kinases is the mediator of p53 in growth suppression and a marker of cellular senescence. p53 signalling encodes information about signal intensity, duration and identity in complex dynamics. I studied how these p53 dynamics are related to p21 dynamics in the same cell. It could be shown that p53 and p21 dynamics were not independent and that distinct signalling dynamic shape population response dynamics after application of genotoxic stress. This was shown by using clustering based on multivariate Dynamic Time Warping similarity estimates. Signalling classes and dynamics were connected to cell cycle state

p53 dynamics in single cells are temperature-sensitive

Cells need to preserve genome integrity despite varying cellular and physical states. p53, the guardian of the genome, plays a crucial role in the cellular response to DNA damage by triggering cell cycle arrest, apoptosis or senescence. Mutations in p53 or alterations in its regulatory network are major driving forces in tumorigenesis. As multiple studies indicate beneficial effects for hyperthermic treatments during radiation- or chemotherapy of human cancers, we aimed to understand how p53 dynamics after genotoxic stress are modulated by changes in temperature across a physiological relevant range. To this end, we employed a combination of time-resolved live-cell microscopy and computational analysis techniques to characterise the p53 response in thousands of individual cells. Our results demonstrate that p53 dynamics upon ionizing radiation are temperature dependent. In the range of 33 °C to 39 °C, pulsatile p53 dynamics are modulated in their frequency. Above 40 °C, which corresponds to mild hyperthermia in a clinical setting, we observed a reversible phase transition towards sustained hyperaccumulation of p53 disrupting its canonical response to DNA double strand breaks. Moreover, we provide evidence that mild hyperthermia alone is sufficient to induce a p53 response in the absence of genotoxic stress. These insights highlight how the p53-mediated DNA damage response is affected by alterations in the physical state of a cell and how this can be exploited by appropriate timing of combination therapies to increase the efficiency of cancer treatments

p53 dynamics in single cells are temperature-sensitive.

Cells need to preserve genome integrity despite varying cellular and physical states. p53, the guardian of the genome, plays a crucial role in the cellular response to DNA damage by triggering cell cycle arrest, apoptosis or senescence. Mutations in p53 or alterations in its regulatory network are major driving forces in tumorigenesis. As multiple studies indicate beneficial effects for hyperthermic treatments during radiation- or chemotherapy of human cancers, we aimed to understand how p53 dynamics after genotoxic stress are modulated by changes in temperature across a physiological relevant range. To this end, we employed a combination of time-resolved live-cell microscopy and computational analysis techniques to characterise the p53 response in thousands of individual cells. Our results demonstrate that p53 dynamics upon ionizing radiation are temperature dependent. In the range of 33 °C to 39 °C, pulsatile p53 dynamics are modulated in their frequency. Above 40 °C, which corresponds to mild hyperthermia in a clinical setting, we observed a reversible phase transition towards sustained hyperaccumulation of p53 disrupting its canonical response to DNA double strand breaks. Moreover, we provide evidence that mild hyperthermia alone is sufficient to induce a p53 response in the absence of genotoxic stress. These insights highlight how the p53-mediated DNA damage response is affected by alterations in the physical state of a cell and how this can be exploited by appropriate timing of combination therapies to increase the efficiency of cancer treatments