RepoMed (Medizinische Hochschule Hannover)
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Einfluss der MicroRNA miR-302d, miR-93 und miR-17 auf die durch den Tumornekrosefaktor induzierte Fibrose des retinalen Pigmentepithels bei der altersbedingten Makuladegeneration
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In Vitro Differentiation of Myoblast Cell Lines on Spider Silk Scaffolds in a Rotating Bioreactor for Vascular Tissue Engineering
Get PDFFunctional construction of tissue-engineered vessels as an alternative to autologous vascular grafts has been shown to be feasible, however the proliferation of seeded smooth-muscle cells remains a limiting factor. We employed a rotating bioreactor system to improve myoblast cell differentiation on a spider silk scaffold for tissue-engineered vessel construction. C2C12 myofibroblast cells were seeded on the surface of spider silk scaffold constructs and cultivated in a rotating bioreactor system with a continuous rotation speed (1 rpm). Cell function, cell growth and morphological structure and expression of biomarkers were analyzed using scanning electron microscopy, the LIVE/DEAD® assay, Western blot and quantitative real-time PCR analyses. A dense myofibroblast cell sheet could be developed which resembled native blood vessel muscular tissue in morphological structure and in function. Bioreactor perfusion positively affected cell morphology, and increased cell viability and cell differentiation. The expression of desmin, MYF5 and MEF2D surged as an indication of myoblast differentiation. Cell-seeded scaffolds showed a tear-down at 18 N when strained at a set speed (20 mm min-1). Spider silk scaffolds appear to offer a reliable basis for engineered vascular constructs and rotating bioreactor cultivation may be considered an effective alternative to complex bioreactor setups to improve cell viability and biology
Acute echocardiographic and electrocardiographic effects of triggered left ventricular pacing
Get PDFCardiac resynchronization therapy (CRT) is an essential pillar in the therapy of heart failure patients with reduced ejection fraction (HFrEF) presenting with broad left bundle branch block (LBBB) or pacemaker dependency. To achieve beneficial effects, CRT requires high bi-ventricular (BiV) pacing rates. Therefore, device-manufacturers designed pacing algorithms which maintain high BiV pacing rates by a left ventricular (LV) pacing stimulus immediately following a right ventricular sensed beat. However, data on clinical impact of these algorithms are sparse. We studied 17 patients implanted with a CRT device providing triggered left ventricular pacing (tLVp) in case of atrioventricular nodal conduction. Assessment of LV dyssynchrony was performed using echocardiographic and electrocardiographic examination while CRT-devices were set to three different settings: 1. Optimized bi-ventricular-stimulation (BiV); 2. Physiological AV nodal conduction (tLVp-off); 3. Physiological AV nodal conduction and tLVp-algorithm turned on (tLVp-on). QRS duration increased when the CRT-device was set to tLVp-off compared to BiV-Stim, while QRS duration was comparable to BiV-Stim with the tLVp-on setting. Echocardiographic analysis revealed higher dyssynchrony during tLVp-off compared to BiV-Stim. TLVp-on did not improve LV dyssynchrony compared to tLVp-off. QRS duration significantly decreased using tLVp-algorithms compared to physiological AV nodal conduction. However, echocardiographic examination could not show functional benefit from tLVp-algorithms, suggesting that these algorithms are inferior to regular biventricular pacing regarding cardiac resynchronization. Therefore, medical treatment and ablation procedures should be preferred, when biventricular pacing rates have to be increased. TLVp-algorithms can be used in addition to these treatment options
Vergleich des Kurz- und Langzeit-Outcomes nach operativ versorgter nekrotisierender Enterokolitis, fokaler intestinaler Perforation oder Mekoniumileus bei Frühgeborenen mit einem Geburtsgewicht unter 1500g
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Advancement of door-to-needle times in acute stroke treatment after repetitive process analysis: never give up!
Get PDFBackground In acute ischemic stroke, timely treatment is of utmost relevance. Identification of delaying factors and knowledge about challenges concerning hospital structures are crucial for continuous improvement of process times in stroke care. Objective In this study, we report on our experience in optimizing the door-to-needle time (DNT) at our tertiary care center by continuous quality improvement. Methods Five hundred forty patients with acute ischemic stroke receiving intravenous thrombolysis (IVT) at Hannover Medical School were consecutively analyzed in two phases. In study phase I, including 292 patients, process times and delaying factors were collected prospectively from May 2015 until September 2017. In study phase II, process times of 248 patients were obtained from January 2019 until February 2021. In each study phase, a new clinical standard operation procedure (SOP) was implemented, considering previously identified delaying factors. Pre- and post-SOP treatment times and delaying factors were analyzed to evaluate the new protocols. Results In study phase I, SOP I reduced the median DNT by 15 min. The probability to receive treatment within 30 min after admission increased by factor 5.35 [95% confidence interval (CI): 2.46-11.66]. Further development of the SOP with implementation of a mobile thrombolysis kit led to a further decrease of DNT by 5 min in median in study phase II. The median DNT was 29 (25th-75th percentiles: 18-44) min, and the probability to undergo IVT within 15 min after admission increased by factor 4.2 (95% CI: 1.63-10.83) compared with study phase I. Conclusion Continuous process analysis and subsequent development of targeted workflow adjustments led to a substantial improvement of DNT. These results illustrate that with appropriate vigilance, there is constantly an opportunity for improvement in stroke care
Long term consequences of COVID-19 and the pandemic (The DEFEnse Against COVID-19 (DEFEAT CORONA) Study protocol): an online-based longitudinal observational study.
No full textBackground With population-wide vaccination availability, the global COVID-19 pandemic entered a new phase. In spite vaccination status, some people who were infected with SARS-CoV-2 experience long-term symptoms. Objective We aim to characterize long-term effects of a SARS-CoV-2 infection and the pandemic. We want to build symptom clusters and determine risk factors for developing Long COVID symptoms. Furthermore, we assess social participation and health-related quality of life in Long COVID patients and in the general population during a global pandemic. Methods With a mixed-method online approach, we aim to recruit 2000 people in Germany who are more than 18 years old and able to give informed consent. In the quantitative arm of the study, we identify symptoms of and predictive factors for Long COVID manifestations with cluster analysis and assess social participation during the pandemic with standardized questionnaires. The qualitative arm of the study uses individual interviews and focus group discussions to better understand the illness experience of persons who experience Long COVID. Results The recruitment started in September 2021. Up until July 2022, we recruited approx. 4500 participants via our online database (www.defeat-corona.de). Conclusions This study aims to build an innovative, patient-centered research online-platform appropriate for the pandemic situation by minimizing physical contact between study personnel and participants. All study activities are designed to better understand the Long COVID syndrome, social participation during the pandemic and the illness experiences of persons affected by Long COVID. Clinicaltrial The study was registered on 9th September 2021 in the German Clinical Trial Registry (DRKS00026007). International registered report DERR1-10.2196/38718
How Should Deceased Donor Organs Be Allocated?: The Patient's Perspective Derived from Semi-Structured Interviews
No full textPurpose The gap between the supply and demand for deceased donor organs is increasing worldwide, while patients on waiting lists for organ transplantation die. This situation requires ethical donor organ allocation rules. The patients' perspective on donor organ allocation rules offers a highly relevant and unique perspective that may differ from the perspectives of physicians and the general public. Patients and methods Semi-structured telephone interviews were conducted with the regional group coordinators of the federal self-help organization for organ transplanted patients and their relatives in Germany in early 2021. Twelve interviews were conducted with patients and relatives of transplantation patients who received transplants for the affected organs including the lungs, heart, kidney, and liver. Transcripts were analyzed using the deductive framework method which was based on an earlier study. All criteria were reported following the COREQ statement. Results Participants emphasized aspects of "medical urgency" and "effectiveness/benefit" of transplantation and associated trade-offs as well as the recipient's responsibility for organ failure ("own fault"), the appreciation for the gifted graft and the patient's capability of taking care of it ("appreciation/responsibility"). Patients acknowledged that urgent patients should be prioritized and they showed a clear preference toward allocation rules that strive to maximize both the life years and quality of life gained by transplantation. Conclusion The patients' perspective is unique in that patients agree on certain rules for allocation and share many preferences, but also have a hard time finding clear cutoff points when considering selecting a participant for allocation. Patient representatives should therefore be consulted in the debate on donor organ allocation rules