Refine
Has Fulltext
- yes (27)
Is part of the Bibliography
- yes (27)
Year of publication
Document Type
- Journal article (25)
- Doctoral Thesis (2)
Keywords
- breast cancer (3)
- AFM (1)
- AKT1 (1)
- Automatische Biegewinkelmessung (1)
- B cell deficiency (1)
- B-cells (1)
- BMP-Mutanten (1)
- BMP-mutants (1)
- Basen-Exzisionsreparatur (1)
- Bessle functions (1)
Institute
- Physikalisches Institut (4)
- Institut für Klinische Neurobiologie (3)
- Klinik und Poliklinik für Mund-, Kiefer- und Plastische Gesichtschirurgie (3)
- Neurochirurgische Klinik und Poliklinik (3)
- Theodor-Boveri-Institut für Biowissenschaften (3)
- Institut für Klinische Epidemiologie und Biometrie (2)
- Kinderklinik und Poliklinik (2)
- Klinik und Poliklinik für Anästhesiologie (ab 2004) (2)
- Rudolf-Virchow-Zentrum (2)
- Urologische Klinik und Poliklinik (2)
Sonstige beteiligte Institutionen
EU-Project number / Contract (GA) number
- 641833 (1)
Background
Severe COVID-19 induced acute respiratory distress syndrome (ARDS) often requires extracorporeal membrane oxygenation (ECMO). Recent German health insurance data revealed low ICU survival rates. Patient characteristics and experience of the ECMO center may determine intensive care unit (ICU) survival. The current study aimed to identify factors affecting ICU survival of COVID-19 ECMO patients.
Methods
673 COVID-19 ARDS ECMO patients treated in 26 centers between January 1st 2020 and March 22nd 2021 were included. Data on clinical characteristics, adjunct therapies, complications, and outcome were documented. Block wise logistic regression analysis was applied to identify variables associated with ICU-survival.
Results
Most patients were between 50 and 70 years of age. PaO\(_{2}\)/FiO\(_{2}\) ratio prior to ECMO was 72 mmHg (IQR: 58–99). ICU survival was 31.4%. Survival was significantly lower during the 2nd wave of the COVID-19 pandemic. A subgroup of 284 (42%) patients fulfilling modified EOLIA criteria had a higher survival (38%) (p = 0.0014, OR 0.64 (CI 0.41–0.99)). Survival differed between low, intermediate, and high-volume centers with 20%, 30%, and 38%, respectively (p = 0.0024). Treatment in high volume centers resulted in an odds ratio of 0.55 (CI 0.28–1.02) compared to low volume centers. Additional factors associated with survival were younger age, shorter time between intubation and ECMO initiation, BMI > 35 (compared to < 25), absence of renal replacement therapy or major bleeding/thromboembolic events.
Conclusions
Structural and patient-related factors, including age, comorbidities and ECMO case volume, determined the survival of COVID-19 ECMO. These factors combined with a more liberal ECMO indication during the 2nd wave may explain the reasonably overall low survival rate. Careful selection of patients and treatment in high volume ECMO centers was associated with higher odds of ICU survival.
Kinesins play an important role in many physiological functions including intracellular vesicle transport and mitosis. The emerging role of kinesins in different cancers led us to investigate the expression and functional role of kinesins in meningioma. Therefore, we re-analyzed our previous microarray dataset of benign, atypical, and anaplastic meningiomas (n = 62) and got evidence for differential expression of five kinesins (KIFC1, KIF4A, KIF11, KIF14 and KIF20A). Further validation in an extended study sample (n = 208) revealed a significant upregulation of these genes in WHO°I to °III meningiomas (WHO°I n = 61, WHO°II n = 88, and WHO°III n = 59), which was most pronounced in clinically more aggressive tumors of the same WHO grade. Immunohistochemical staining confirmed a WHO grade-associated upregulated protein expression in meningioma tissues. Furthermore, high mRNA expression levels of KIFC1, KIF11, KIF14 and KIF20A were associated with shorter progression-free survival. On a functional level, knockdown of kinesins in Ben-Men-1 cells and in the newly established anaplastic meningioma cell line NCH93 resulted in a significantly inhibited tumor cell proliferation upon siRNA-mediated downregulation of KIF11 in both cell lines by up to 95% and 71%, respectively. Taken together, in this study we were able to identify the prognostic and functional role of several kinesin family members of which KIF11 exhibits the most promising properties as a novel prognostic marker and therapeutic target, which may offer new treatment options for aggressive meningiomas.
Microstructural Analysis of Peripheral Lung Tissue through CPMG Inter-Echo Time R2 Dispersion
(2015)
Since changes in lung microstructure are important indicators for (early stage) lung pathology, there is a need for quantifiable information of diagnostically challenging cases in a clinical setting, e.g. to evaluate early emphysematous changes in peripheral lung tissue. Considering alveoli as spherical air-spaces surrounded by a thin film of lung tissue allows deriving an expression for Carr-Purcell-Meiboom-Gill transverse relaxation rates R-2 with a dependence on inter-echo time, local air-tissue volume fraction, diffusion coefficient and alveolar diameter, within a weak field approximation. The model relaxation rate exhibits the same hyperbolic tangent dependency as seen in the Luz-Meiboom model and limiting cases agree with Brooks et al. and Jensen et al. In addition, the model is tested against experimental data for passively deflated rat lungs: the resulting mean alveolar radius of RA = 31.46 \(\pm\) 13.15 \(\mu\)m is very close to the literature value (similar to 34 \(\mu\)m). Also, modeled radii obtained from relaxometer measurements of ageing hydrogel foam (that mimics peripheral lung tissue) are in good agreement with those obtained from mu CT images of the same foam (mean relative error: 0.06 \(\pm\) 0.01). The model's ability to determine the alveolar radius and/or air volume fraction will be useful in quantifying peripheral lung microstructure.
Merkel cell carcinoma (MCC) is an aggressive, virus-associated, neuroendocrine tumor of the skin mainly affecting immunocompromised patients. Higher intratumoral infiltration with CD3 and CD8 positive T-cells is associated with a better prognosis, highlighting the relevance of the immune system for MCC development and progression. In this study 21 primary MCCs were stained with immune cell markers including CD3, CD4, CD8, CD68, CD20, and S100. Furthermore, tumor-infiltrating neutrophils, tertiary lymphoid structures and PD-L1 expression were analyzed and correlated with overall and recurrence free survival. All MCCs were Merkel Cell Polyomavirus positive. Overall and recurrence-free survival did not correlate with intra-and peritumoral CD3 and CD8 T-cell infiltration. In addition, no significant association regarding prognosis was found for tumor-associated neutrophils, tumor-associated macrophages or PD-L1 positivity in MCCs. Interestingly, the presence of tertiary lymphoid structures (TLS) in the tumor microenvironment significantly correlated with recurrence-free survival (P=0.025). In addition, TLS were significantly associated with a higher CD8/CD4 ratio in the tumor periphery (P=0.032), but not in the center of the tumor (P > 0.999). These results demonstrate for the first time that TLS, easily assessed in paraffin-embedded tissue in the tumor periphery of MCCs, may be a valuable prognostic factor indicating prolonged recurrence free survival.
Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
Several novel synaptic proteins have been identified by monoclonal antibodies (mAbs) of the Würzburg hybridoma library generated against homogenized Drosophila brains, e.g. cysteine string protein, synapse-associated protein of 47 kDa, and Bruchpilot. However, at present no routine technique exists to identify the antigens of mAbs of our library that label only a small number of cells in the brain. Yet these antibodies can be used to reproducibly label and thereby identify these cells by immunohistochemical staining. Here we describe the staining patterns in the Drosophila brain for ten mAbs of the Würzburg hybridoma library. Besides revealing the neuroanatomical structure and distribution of ten different sets of cells we compare the staining patterns with those of antibodies against known antigens and GFP expression patterns driven by selected Gal4 lines employing regulatory sequences of neuronal genes. We present examples where our antibodies apparently stain the same cells in different Gal4 lines suggesting that the corresponding regulatory sequences can be exploited by the split-Gal4 technique for transgene expression exclusively in these cells. The detection of Gal4 expression in cells labeled by mAbs may also help in the identification of the antigens recognized by the antibodies which then in addition to their value for neuroanatomy will represent important tools for the characterization of the antigens. Implications and future strategies for the identification of the antigens are discussed.
Im Rahmen dieser Doktorarbeit sollte anknüpfend an die Ergebnisse aus vo-rangegangenen Untersuchungen der AG Tessmer, das von Büchner et al. [1] vorgestellte Modell zur DNA-Schadenserkennung, welches im Speziellen auf Daten zu den Glykosylasen hTDG und hOGG1 basierte, auf seine Allgemein-gültigkeit für DNA-Glykosylasen untersucht werden. Das Modell beschreibt den Prozess der Schadenserkennung als eine notwendige Übereinstimmung der passiven Biegung am Schadensort mit dem aktiven BiegungswinkeI der scha-densspezifischen Glykosylase. Ein wesentlicher Bestandteil dieser Arbeit war zudem die Etablierung einer automatisierten Messsoftware zur objektiven Biegewinkelmessung an DNA-Strängen in rasterkraftmikroskopischen Aufnah-men. Dies wurde mit verschiedenen Bildverarbeitungsprogrammen sowie einer in MATLAB implementierten Messsoftware erreicht und das Programm zudem auf die Biegewinkelmessung von proteininduzierten Biegewinkeln erweitert. Zur Anwendung kam die Methode der automatisierten Biegewinkelmessung sowohl an rasterkraftmikroskopischen Aufnahmen der Glykosylase MutY gebunden an ungeschädigter DNA als auch an Aufnahmen von DNA mit und ohne Basen-schaden. Neben oxoG:A und G:A, den spezifischen MutY-Zielschäden, wurden auch andere Basenschäden wie beispielsweise oxoG:C und ethenoA:T vermes-sen und zudem die von der Glykosylase MutY an ungeschädigter DNA induzier-te Biegung mit den Biegewinkeln der jeweiligen Zielschäden verglichen. Die Übereinstimmung in den Konformationen der Zielschäden und der Reparatur-komplexe auch für die Glykosylase MutY (wie bereits für hTDG und hOGG1 in oben genannter Arbeit gezeigt) erlauben ein verbessertes Verständnis der Schadenssuche und -erkennung durch DNA-Glykosylasen, indem sie die All-gemeingültigkeit einer Biegungsenergie-basierten initialen Schadenserkennung durch DNA-Glykosylasen unterstützen. Die etablierte Messsoftware kann zu-künftig an weiteren DNA-Schäden und den entsprechenden Protein-DNA-Komplexen ihre Anwendung finden und kann somit durch die effektive Gewin-nung objektiver Daten in großer Menge zur Stützung des Modells beitragen.
Objectives
The present investigation aimed to evaluate the subjective perception of deformational cranial asymmetries by different observer groups and to compare these subjective perceptions with objective parameters.
Materials and methods
The 3D datasets of ten infants with different severities of deformational plagiocephaly (DP) were presented to 203 observers, who had been subdivided into five different groups (specialists, pediatricians, medical doctors (not pediatricians), parents of infants with DP, and laypersons). The observers rated their subjective perception of the infants’ cranial asymmetries using a 4-point Likert-type scale. The ratings from the observer groups were compared with one another using a multilevel modelling linear regression analysis and were correlated with four commonly used parameters to objectively quantify the cranial asymmetries.
Results
No significant differences were found between the ratings of the specialists and those of the parents of infants with DP, but both groups provided significantly more asymmetric ratings than did pediatricians, medical doctors, or laypersons. Moreover, the subjective perception of cranial asymmetries correlated significantly with commonly used parameters for objectively quantifying cranial asymmetries.
Conclusions
Our results demonstrate that different observer groups perceive the severity of cranial asymmetries differently. Pediatricians’ more moderate perception of cranial asymmetries may reduce the likelihood of parents to seek therapeutic interventions for their infants. Moreover, we identified some objective symmetry-related parameters that correlated strongly with the observers’ subjective perceptions.
Clinical relevance
Knowledge about these findings is important for clinicians when educating parents of infants with DP about the deformity.
Mutual coupling and injection locking of semiconductor lasers is of great interest in non-linear dynamics and its applications for instance in secure data communication and photonic reservoir computing. Despite its importance, it has hardly been studied in microlasers operating at mu W light levels. In this context, vertically emitting quantum dot micropillar lasers are of high interest. Usually, their light emission is bimodal, and the gain competition of the associated linearly polarized fundamental emission modes results in complex switching dynamics. We report on selective optical injection into either one of the two fundamental mode components of a bimodal micropillar laser. Both modes can lock to the master laser and influence the non-injected mode by reducing the available gain. We demonstrate that the switching dynamics can be tailored externally via optical injection in very good agreement with our theory based on semi-classical rate equations. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
In der vorliegenden Untersuchung wurde rekombinantes humanes BMP-2 sowie zwei genetisch veränderte Mutanten T3 und T4, jeweils mit rhTGF-ß1 kombiniert. Das Ziel der Studie bestand darin, nachzuweisen, ob TGF-ß1 die osteoinduktive Potenz dieser BMPs steigert. Als Proteinkonzentrationen wurden 0,5µg und 1µg des jeweiligen Proteins gewählt. Des Weiteren wurde untersucht, ob rhTGF-ß1 alleine im heterotopen Implantatlager osteoinduktive Eigenschaften aufweist. Als Träger für die Proteine wurden bovine ICBM-Zylinder, die aus Spongiosa von Röhrenknochen gewonnen wurden, verwendet. Die ICBM-Zylinder wurden in die Oberschenkelmuskulatur von Sprague-Dawley-Ratten implantiert. Dabei wurden die mit BMPs und TGF-ß1 kombinierten Proben jeweils in den linken Oberschenkel, die mit den BMPs ohne TGF-ß1 rekonstituierten Proben in den rechten Oberschenkel implantiert. ICBM-Zylinder, die nur mit TGF-ß1 rekonstituiert waren, wurden „leeren“ ICBM-Zylindern als Kontrollgruppe gegenübergestellt. Die Ratten wurden innerhalb des Untersuchungszeitraumes von 28 Tagen am 5., 11., 17., 23. und 28. Tag post operativ geröntgt. Ebenso am 5., 11., 17., 23. und 28.Tag wurden ihnen fluorochrome Farbstoffe injiziert. Die quantitative Auswertung erfolgte über die Röntgenverlaufskontrolle und die Fluoreszenzmikroskopie, die qualitative Auswertung über die histologische Untersuchung von Trenndünnschliffen unter dem Lichtmikroskop. Die ICBM-Zylinder der Kontrollgruppe sowie die nur mit TGF-ß1 rekonstituierten Zylinder zeigten weder röntgenologisch, noch histologisch Hinweise auf eine Knochenneubildung. Die quantitativen Ergebnisse zeigten, dass TGF-ß1 die osteoinduktive Aktivität von rhBMP-2, T3 oder T4 steigert. In der T3-Gruppe wurde der stärkste synergistische Effekt nachgewiesen. Dieser war in der T4- und der BMP-2-Gruppe kleiner. Die Auswertung der polychromen Sequenzmarkierung bestätigte quantitativ und qualitativ die Röntgenanalyse. In den Histologien konnten keine morphologischen Unterschiede des neu gebildeten Knochengewebes zwischen den einzelnen Gruppen nachgewiesen werden. In der vorliegenden Studie wurde ein synergistischer Effekt von BMPs und TGF-ß1 nachgewiesen. Insgesamt war das Ausmaß jedoch nicht so ausgeprägt wie in der Literatur beschrieben [71]. Für eine klinische Applikation entsteht durch die Kombination der Wachstumsfaktoren kein deutlicher Vorteil. Es empfiehlt sich vielmehr die Applikation einer in ihrer Wirkung optimierten Monosubstanz, wie z.B. die in dieser Arbeit vorgestellte BMP-Mutante T4.