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Prospektive Untersuchung der diagnostischen Eigenschaften von Screeninginstrumenten und des klinischen Verlaufs des Schlaganfalldelirs
Get PDFDiese Arbeit befasst sich mit der Leistungsfähigkeit diagnostischer Instrumente zur Erkennung eines Delirs nach ischämischem Schlaganfall (PSD). Die Ergebnisse der von uns untersuchten Methoden, Nursing Delirium Screening Scale (Nu-DESC), Rapid Delirium Assessment Test (4AT) sowie Confusion Assessment Method (CAM), wurden der Diagnose mittels Kriterien des Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) gegenübergestellt. Diesem als Goldstandard gesetzten Diagnostikum als statistisch ebenbürtig erwies sich lediglich die CAM, weshalb eine Empfehlung zur alltäglichen Nutzung nur für dieses Instrument ausgesprochen werden kann. Keines der Instrumente wurde durch präexistente kognitive Einschränkungen der Patient*innen beeinflusst, allerdings wurde mit steigender Beeinträchtigung durch den Schlaganfall ein PSD durch die CAM zunehmend schlechter erkannt. Des Weiteren beschrieb das Instrument Patient*innen mit moderater Desorientierung häufiger als falsch-positiv. Die zeitlich engmaschige Datenerhebung während des Krankenhausaufenthaltes ermöglichte darüber hinaus erstmals eine genauere Darstellung des Verlaufes eines PSD. Unsere Ergebnisse zeigen, dass PSD mit einer Inzidenz von 39 % deutlich mehr Patient*innen betrifft als bisher angenommen. Hierbei traten nahezu alle Fälle innerhalb der ersten 72 Stunden und somit in engem zeitlichem Zusammenhang mit dem ischämischen Ereignis auf. Als signifikante Prädiktoren identifizierten wir das Alter in Jahren sowie Summenwerte der National Institute of Health Stroke Scale (NIHSS). Schließlich konnten wir zeigen, dass tägliches Screening, vorzugsweise gegen Abend, nötig ist, um weniger als 25 % der Fälle zu übersehen. Mehrfach tägliche Testungen hingegen werden durch unsere Berechnungen nicht unterstützt.
Die globale Relevanz des Schlaganfalls und des PSD für Gesellschaft, Gesundheitssystem und, insbesondere auch langfristig, die Betroffenen berücksichtigend, sollten diese Erkenntnisse zukünftig in neuen Leitlinien implementiert werden und in die standardmäßige Behandlung von Schlaganfallpatient*innen einfließen
Studies on the spatiotemporal occurence of mosquitoe-borne pathogens in German mosquitoes (Culicidae: Diptera) and on the microbiome of the invasive Asian tiger mosquito (Aedes albopictus) and its displacement potential towards native species
Get PDFTo promptly register future outbreaks of mosquito-borne diseases of humans and animals and to be able to take prophylactic measures if necessary, the examination of German mosquitoes for pathogens is essential. The vector competence of a mosquito can be influenced by, among other things, microorganisms that are part of its microbiome. Therefore, studies of the microbiome of native and invasive mosquito species, which may serve as vectors of a variety of pathogens relevant to humans and animals, is essential. Among these vectors, the mosquito species Ae. albopictus, a neozoic species in Germany, plays a dominant role. This species has been present in Germany since 2007, but it is unclear whether it is an invasive species according to the EU Environmental and Nature Protection Act. The classification of Ae. albopictus as an invasive species could enable control measures for this species to be enforced by law, thereby preventing the spread of this highly invasive vector species. Therefore, it is particularly crucial to investigate different fields of mosquito biology to develop an integrated concept for the protection of the human population. On the one hand, this requires knowledge about the spread of mosquito-borne pathogens. Knowing which pathogens circulate in German mosquitoes and which areas of Germany are hostspots of circulation would make it possible to take prophylactic and timely measures to reduce the risk of transmission to humans and animals. New, efficient, and practicable control measures for mosquitoes must be developed to prevent the establishment of new vector species in Germany and to be able to regulate German mosquito populations if necessary. However, to be able to implement control measures against invasive mosquito species including vector species, their distribution within Germany and their influence on the German mosquito fauna must be investigated. Only when this knowledge is available legal and uniform control measures can be taken. Since these interdisciplinary studies on various aspects of the German mosquito fauna are critical for a holistic knowledge of mosquitoes in Germany, three different aspects of the mosquito fauna are dealt with in this dissertation. These three aspects overlap and thus provide a coherent picture of the German mosquito fauna.
This study aimed to investigate whether Ae. albopictus is an invasive species in Germany using three taxa from the Cx. pipiens complex in a competition experiment. In addition, this study examined the microbiota of Ae. albopictus from German populations and screened mosquitoes that were captured in Germany for human and veterinary viruses. On the one side, these studies are meant to monitor the spread of mosquito-borne pathogens in Germany to enable timely control measures to be adopted. On the other side, the microorganisms registered in Ae. albopictus may help to modify the vector competence of Ae. albopictus or be used to develop new vector control measures in the future
Literaturrecherche zu In-vitro-Wundheilungsmodellen mit der Zielsetzung der Auswahl und Erprobung eines Modells zur Prüfung von antiseptischen Wirkstoffen bzw. Verfahren zur Wundbehandlung
Get PDFIn Deutschland erleiden 4,9 % der Patienten postoperativ eine Wundinfektion mit Verdopplung der Mortalität, Kostenerhöhung um 10.000 € pro Patient und der Mehrbelastung von 892 Mill. € für die Versicherungen (Eckmann et al. 2022). Hauptinfektionsquelle ist die in das OP-Gebiet gelangende Flora aus der umgebenden Haut. Diese ist durch die präoperative Hautantiseptik mit Antiseptika nur unvollständig eliminierbar. Durch Fern-UV-C-Bestrahlung des OP-Felds vor dem Wundverschluss könnten während der OP in das Wundgebiet freigesetzte Bakterien eliminiert und so das Infektionsrisiko gesenkt werden. Zur Untersuchung der Eignung des Einsatzes von Fern-UV-C-Bestrahlung sollte auf Grundlage einer Literaturrecherche ein Wundheilungsmodell entwickelt werden.
Aufgrund der Ergebnisse der Literaturrecherche ist die Wahl auf ein 3D-Wundheilungsmodell gefallen. Die verwendete Modellvariante bietet den Kompromiss zwischen der Überschaubarkeit verwendeter Materialien, zu betrachtender Modellaspekte, einfacher Handhabung und Auswertung und andererseits die Komplexität eines 3D-Modells mit vergleichsweise aussagekräftigen Ergebnissen. Es konnte gezeigt werden, dass sich das 3D-Wundheilungsmodell prinzipiell zur Prüfung von Fern-UV-C-Bestrahlung eignet, es allerdings einiger Anpassungen bedurfte. Die hergestellten Zellkollagene blieben über einen ausreichend langen Zeitraum von mindestens 14 d vital und bildeten Epithelzungen aus. Anpassungen des ursprünglichen Protokolls erfolgten in der Zusammensetzung des Zellkulturmediums, der Durchführung der Zellkollagenherstellung, der verwendeten Zellart und der durchgeführten Verwundungsvariante, verbunden mit einer Erhöhung der Stichprobengröße für die statistische Auswertbarkeit
Have extraction patterns in German adults with severe periodontitis changed between 2000 and 2010? Results from two cohort studies
Get PDFAim: The aim of this study was to evaluate whether extraction thresholds in persons with
severe periodontitis have changed between 2000 and 2010 and whether potential shifts have
contributed to the reported decrease in tooth extractions in German adults over the last
decades.
Materials and methods: Data from two German population-based cohort studies in Northeast
Germany (Studies of Health in Pomerania; SHIP-START [baseline 1997-2001; 11-year
follow-up] and SHIP-TREND [baseline 2008-2012; 7-year follow-up] were used. In SHIP-
START (SHIP-TREND) 522 (478) participants with severe periodontitis according to the
CDC/AAP case definition were included. Patterns of maximum probing depth (PD) and
maximum clinical attachment level (CAL) for retained and extracted teeth were compared
between SHIP-START and SHIP-TREND participants.
Results: No major differences in patterns of baseline maximum CAL of retained or extracted
teeth were detected between SHIP-START and SHIP-TREND. Extraction thresholds were
identified at the baseline maximum CAL ≥6 mm and ≥9 mm. Tooth-level incidence rates for
extraction for baseline maximum CAL of 6 mm were comparable between SHIP-START and
SHIP-TREND (17.1 versus 15.9 events per 1000 person-years).
Conclusions: After a decade, teeth in persons with severe periodontitis were still extracted
with minor or moderate attachment loss. A change of extraction pattern did not contribute to
the higher tooth retention rate
Bacteria employ lysine acetylation of transcriptional regulators to adapt gene expression to cellular metabolism
Get PDFThe Escherichia coli TetR-related transcriptional regulator RutR is involved in the coordination of pyrimidine and purine metabolism. Here we report that lysine acetylation modulates RutR function. Applying the genetic code expansion concept, we produced site-specifically lysine-acetylated RutR proteins. The crystal structure of lysine-acetylated RutR reveals how acetylation switches off RutR-DNA-binding. We apply the genetic code expansion concept in E. coli in vivo revealing the consequences of RutR acetylation on the transcriptional level. We propose a model in which RutR acetylation follows different kinetic profiles either reacting non-enzymatically with acetyl-phosphate or enzymatically catalysed by the lysine acetyltransferases PatZ/YfiQ and YiaC. The NAD+-dependent sirtuin deacetylase CobB reverses enzymatic and non-enzymatic acetylation of RutR playing a dual regulatory and detoxifying role. By detecting cellular acetyl-CoA, NAD+ and acetyl-phosphate, bacteria apply lysine acetylation of transcriptional regulators to sense the cellular metabolic state directly adjusting gene expression to changing environmental conditions
Protein Engineering of Amine Transaminases and Methyltransferases using Machine Learning and High-Throughput Screening Tools
Get PDFEnzymes harbor immense potential for application in industrial synthesis processes, however the need for improvement in activity, selectivity, a broadened substrate scope or an increased thermal and organic solvent tolerance to meet the required non-natural industrial conditions requires optimization. Different protein engineering approaches are known and undergone to optimize specific properties of these biocatalysts. Machine learning emerged as a novel approach to alter the properties through algorithmic pattern recognition in data and has the potential for a paradigm shift in protein engineering. The complementary role of machine learning for protein engineering is exemplified for amine transaminases in Article I and Article II. Based on the key observations, a machine learning model was built that incorporated information regarding steric and electronic properties of amine substrates and active site residues. The predictor was improved in iterative computational prediction and experimental validation cycles and was used for the correct prediction of variants with improved activity and accurate activity estimation for a novel substrate. Article II envisioned further exploration of the potential of the machine learning predictor design with a focus on more challenging bulky amine substrates, prevalent in active pharmaceutical ingredient (API) precursors. Simultaneously, the key steps involved in the design of machine learning-guided protein engineering were formulated in a protocol. The predictor was successfully used for the prediction of higher active variants. In concept Article III the results of Article I are placed into context of the lack of machine learning descriptors for substrate scope enhancements. In addition, current limitations and potential improvements for data-driven protein engineering in the future are further elaborated on. Lastly, Article IV describes a developed high-throughput assay for S-adenosyl-L-methionine-dependent methyltransferases to address one of the restrictions mentioned in Article III. This facilitated data generation should accelerate methyltransferase engineering campaigns and could enable machine learning-based investigations in the future
Storage and manipulation of large electron or positron ensembles in a multi-cell Penning-Malmberg trap
Get PDFFor the creation of a positron-electron (pair) plasma the A Positron Electron eXperiment (APEX) collaboration needs large quantities of positrons. Accumulating many positrons is an experimentally challenging task. To achieve this task, a new prototype multi cell Penning-Malmberg trap (MCT) was designed and constructed. The accumulation of large charged-particle ensembles with one charge sign dominating, so-called non-neutral plasmas, in Penning-Malmberg traps is limited by the plasma space charge. The MCT avoids this limitation by separating the plasma space charge into multiple storage traps in the same magnetic field. This MCT includes a master-cell, and three storage cells (one on-axis, and two off-axis). With this device plasma transfer to the off-axis cells was tested and improved. The goal was to transfer multiple plasmas off-axis while avoiding particle losses during the process.
The dissertation introduces the vacuum setup, diagnostics, and the MCT, and explores its operation. The plasma creation process, cyclotron cooling, and the plasma confinement is detailly described. Different schemes for the autoresonant excitation of the diocotron mode are discussed as well as the dynamics during the transport to the off-axis cells. These dynamics are dominated by competing diocotron drift modes that can lead to significant particle losses. New techniques are presented which allow to suppress these modes. These techniques mitigate losses and centre the plasma in the off-axis cells during the transfer process, significantly improving it. In addition, the dissertation demonstrates the first consecutive transfer and confinement in two different off-axis cells. The confinement in multiple off-axis traps is a milestone for the future use of a MCT at the NEPOMUC positron source in Munich
Septischer Schock – Entwicklung eines Zellkulturmodells zur Untersuchung des Mechanismus der Förderung eines Kapillarlecks durch Vasopressin-2-Rezeptor- Stimulation
Get PDFIm septischen Schock wird zur Kreislaufstabilisierung neben Katecholaminen auch Vasopressin eingesetzt. Aus dem Tiermodell ist bekannt, dass die selektive AVPR1a Stimulation der unspezifischen AVPR-Stimulation durch Vasopressin bezüglich des Outcomes und der Hämodynamik überlegen ist. Die Rolle der Vasopressinrezeptoren und die molekularen Mechanismen im Zusammenhang mit dem Kapillarleck sind aber noch weitestgehend unerforscht. Bekannt ist, dass es bei Stimulation des AVPR2 durch Desmopressin zu einer Ausschüttung von vWF aus den Weibel-Palade-Bodies in vivo kommt. Die Weibel-Palade-Bodies enthalten unter anderen auch Ang-2, welches bei septischen Patienten im Blut erhöht ist und mit anderen inflammatorischen Werten, wie dem CRP und dem TNF-alpha korreliert. Auch für andere Inhaltsstoffe in den Weibel-Palade-Bodies beispielsweise P-Selektin ist dies nachgewiesen. Daraus resultiert die Frage, welchen Einfluss Vasopressin auf die Ausschüttung kapillär destabilisierender Mediatoren hat und weiterführend auch auf die Ausbildung eines Kapillarlecks. Ziel dieser Arbeit war es, ein Zellkulturmodell zur Untersuchung von AVPR1a und AVPR2- Agonisten und -Antagonisten bezüglich ihrer Ausschüttung von vWF, Ang-1, Ang-2 und P-Selektin zu entwickeln und ihre Auswirkung auf das Kapillarleck in vivo zu analysieren.
HUVEC, HDMEC und HPMEC, primäre endotheliale mikrovaskuläre Zellen, wurden mittels Immunfluoreszenz, Western-Blot, FACS und rtPCR auf die Expression von AVPR1a, AVPR2 und vWF untersucht. Primär musste verifiziert werden, dass es bei Stimulation von AVPR2 durch Desmopressin in diesem Modell zu einer Ausschüttung von vWF aus Weibel-Palade-Bodies kommt. Hierzu wurde ein Protokoll erarbeitet, mit welchem anschließend die Ausschüttung von anderen Mediatoren mittels ELISA analysiert werden konnte. Außerdem der Trans-Well- Assays etabliert und analysiert mit der Frage, ob diese Methode mittels TEER und Durchlässigkeit für FITC-Albumin zur In-vitro-Untersuchung der Wirkung von Desmopressin auf einen endothelialen Monolayer geeignet ist.
Entgegen den Beschreibungen in der Literatur konnte HUVEC nicht als Kontrollzelllinie genutzt werden, da sie, wie mittels Immunfluoreszenz, Western-Blot und rtPCR nachgewiesen wurde, genauso wie HDMEC und HPMEC sowohl AVPR1, als auch AVPR 2 exprimieren. Ebenfalls konnte gezeigt werden, dass HPMEC aufgrund seiner geringen Grundproduktion an vWF nicht als Zelllinie zur Untersuchung der Ausschüttung von vWF geeignet sind. In Etablierungsversuchen konnte herausgefunden werden, dass es nach 10-minütiger Inkubation mit 1000 nM Desmopressin in KRBP zu einem Anstieg von vWF und Ang-2 im Überstand kam, während Ang-1 und P-Selektin unverändert niedrig blieben. Vorausgehend mussten andere Inkubationszeiträume, andere Inkubationsmedien und Inkubationswells getestet werden. Im Verlauf zeigte sich das Arbeiten mit primären Zellen bezüglich der Reproduzierbarkeit unbeständig. Auch konnten keine Effekte durch Vasopressin, POV oder Tolvaptan dargestellt werden. Bei der Etablierung des Trans-Well-Assay zeigte sich die Wachstumskontrolle mittels TEER nicht geeignet. Die Versuchsdurchführung mit Desmopressininkubation des endothelialen Monolayers im Trans-Well unterlag sowohl in der TEER Messung als auch bezüglich der Durchlässigkeit für FITC-Albumin vielen Schwankungen, und es konnten keine validen Ergebnisse erzielt werden. Der Trans-Well-Assay kann als Untersuchungsmethode in diesem Set-up nicht empfohlen werden.
Da die Versuchsergebnisse sehr variierten, gilt es diese im Verlauf zu minimieren. Hierzu wäre ein Modell, welches eine kontinuierliche Messung möglich macht von Vorteil. Auch scheint die Ausbildung von AVPR1a und AVPR2, sowie die Synthese von vWF und anderer Bestandteile der Weibel-Palade-Bodies starken Schwankungen zu unterliegen, hier könnten transfizierte, immortalisierte Zellen für mehr Stabilität sorgen, allerdings würde dies auch eine Entfernung zu in vivo Bedingungen bedeuten.In the setting of septic shock, vasopressin is administered alongside catecholamines for circulatory stabilization. Animal models have revealed that selective AVPR1a stimulation surpasses non-specific AVPR stimulation by vasopressin in terms of both outcome and hemodynamics. However, the roles of vasopressin receptors and the molecular mechanisms associated with capillary leakage remain largely unexplored. Stimulation of AVPR2 by Desmopressin has been observed to result in the release of von Willebrand Factor (vWF) from Weibel-Palade-Bodies in vivo. These bodies also contain Ang-2, elevated in the blood of septic patients, correlating with inflammatory markers such as CRP and TNF-alpha, as demonstrated for other Weibel-Palade-Body components, including P-selectin. This prompts the question of vasopressin's influence on the release of capillary destabilizing mediators and, consequently, the development of capillary leakage. The aim of this study was to develop a cell culture model to investigate AVPR1a and AVPR2 agonists and antagonists regarding their release of vWF, Ang-1, Ang-2, and P-selectin and to analyze their impact on capillary leakage in vivo.
HUVEC, HDMEC, and HPMEC, primary endothelial microvascular cells, were examined for the expression of AVPR1a, AVPR2, and vWF using immunofluorescence, Western-Blot, FACS, and rtPCR. Verification of AVPR2 stimulation leading to vWF release from Weibel-Palade-Bodies in this model was pivotal. To achieve this, a protocol was devised to subsequently analyze the release of other mediators using ELISA. Additionally, the Trans-Well-Assay was established and evaluated to determine its suitability for in vitro examination of Desmopressin's effect on an endothelial monolayer using Transendothelial Electrical Resistance (TEER) and permeability to FITC-labeled albumin.
Contrary to literature descriptions, HUVEC could not serve as a suitable control cell line, as demonstrated by immunofluorescence, Western-Blot, and rtPCR, revealing the expression of both AVPR1a and AVPR2, akin to HDMEC and HPMEC. Furthermore, it was demonstrated that HPMEC, due to their low basal production of vWF, were unsuitable for investigating vWF release. Establishment experiments revealed that a 10-minute incubation with 1000 nM Desmopressin in KRBP led to an increase in vWF and Ang-2 in the supernatant, while Ang-1 and P-selectin remained consistently low. Prior testing encompassed various incubation periods, media, and wells. The use of primary cells proved inconsistent in terms of reproducibility, and no discernible effects of vasopressin, POV, or Tolvaptan were demonstrated. During the establishment of the Trans-Well assay, growth control using TEER was deemed unsuitable. The experimental procedure involving Desmopressin incubation of the endothelial monolayer in the Trans-Well-Assay exhibited substantial fluctuations in both TEER measurement and permeability to FITC-labeled albumin, precluding the acquisition of valid results. Consequently, the Trans-Well-Assay is not recommended as a testing method in this setup.
Given the considerable variability in test results, minimizing these variations over time is imperative. To address this, a model enabling continuous measurement would be advantageous. The synthesis of AVPR1a and AVPR2, as well as the production of vWF and other components within the Weibel-Palade-Bodies, appears to be subject to significant fluctuations. In this context, transfected, immortalized cells could potentially provide more stability, albeit at the cost of a departure from in vivo conditions
Cancer incidence and mortality in the occupational cohort of a German toxic waste landfill: a retrospective cohort study
Get PDFBackground
Employees at the Ihlenberg toxic waste landfill in northern Germany were found to have an increased risk of cancer and cancer-related deaths in previous analyses covering the time period from 1983 to 2008. The present study aimed to quantify cancer risk and all-cause mortality in the employee cohort in 2009 to 2021.
Methods
In this retrospective cohort study, cancers were identified by linkage with cancer registries, and employee deaths were obtained from population registries. Standardized incidence ratios (SIRs) for cancers and standardized mortality ratios (SMRs) were calculated to quantify cancer and mortality risk in the employee cohort. The effects of employment duration and different latency periods up to 30 years were additionally considered.
Results
The cohort of 590 employees (432 men, 158 women) who worked at the landfill for at least 3 months between 1983 and 2018 was established from human resource management documentation and followed from January 1, 2009 until December 31, 2021. During this follow-up period, the SIR for all cancers combined was 0.69 (95% confidence interval (CI): 0.47, 0.98) and the SMR for all-cause mortality was 0.51 (95% CI: 0.35, 0.73). Longer employment at the landfill was not associated with increased cancer incidence or mortality.
Conclusions
Employment at the landfill, expected to reflect occupational exposure to toxic waste, was not associated with increased cancer incidence or mortality in the employee cohort. Preventive measures to reduce exposure and to promote a healthy lifestyle should be maintained at the landfill
An annual land cover dataset for the Baltic Sea Region with crop types and peat bogs at 30 m from 2000 to 2022
Get PDFWe present detailed annual land cover maps for the Baltic Sea region, spanning more than two decades (2000–2022). The maps provide information on eighteen land cover (LC) classes, including eight general LC types, eight major crop types and grassland, and two peat bog-related classes. Our maps represent the first homogenized annual dataset for the region and address gaps in current land use and land cover products, such as a lack of detail on crop sequences and peat bog exploitation. To create the maps, we used annual multi-temporal remote sensing data combined with a data encoding structure and deep learning classification. We obtained the training data from publicly available open datasets. The maps were validated using independent field survey data from the Land Use/Cover Area Frame Survey (LUCAS) and expert annotations from high-resolution imagery. The quantitative and qualitative results of the maps provide a reliable data source for monitoring agricultural transformations, peat bog exploitation, and restoration activities in the Baltic Sea region and its surrounding countries