115 research outputs found
Characterization of Aspergillus terreus Accessory Conidia and Their Interactions With Murine Macrophages
All Aspergillus species form phialidic conidia (PC) when the mycelium is in contact with the air. These small, asexual spores are ideally suited for an airborne dissemination in the environment. Aspergillus terreus and a few closely related species from section Terrei can additionally generate accessory conidia (AC) that directly emerge from the hyphal surface. In this study, we have identified galactomannan as a major surface antigen on AC that is largely absent from the surface of PC. Galactomannan is homogeneously distributed over the entire surface of AC and even detectable on nascent AC present on the hyphal surface. In contrast, β-glucans are only accessible in distinct structures that occur after separation of the conidia from the hyphal surface. During germination, AC show a very limited isotropic growth that has no detectable impact on the distribution of galactomannan. The AC of the strain used in this study germinate much faster than the corresponding PC, and they are more sensitive to desiccation than PC. During infection of murine J774 macrophages, AC are readily engulfed and trigger a strong tumor necrosis factor-alpha (TNFα) response. Both processes are not hampered by the presence of laminarin, which indicates that β-glucans only play a minor role in these interactions. In the phagosome, we observed that galactomannan, but not β-glucan, is released from the conidial surface and translocates to the host cell cytoplasm. AC persist in phagolysosomes, and many of them initiate germination within 24 h. In conclusion, we have identified galactomannan as a novel and major antigen on AC that clearly distinguishes them from PC. The role of this fungal-specific carbohydrate in the interactions with the immune system remains an open issue that needs to be addressed in future research
Clinically Approved Drugs Inhibit the Staphylococcus aureus Multidrug NorA Efflux Pump and Reduce Biofilm Formation
Staphylococcus aureus has acquired resistance to antibiotics since their first use. The S. aureus protein NorA, an efflux pump belonging to the major facilitator superfamily (MFS), contributes to resistance to fluoroquinolones (e.g., ciprofloxacin), biocides, dyes, quaternary ammonium compounds, and antiseptics. Different compounds have been identified as potential efflux pump inhibitors (EPIs) of NorA that result in increased intracellular concentration of antibiotics, restoring their antibacterial activity and cell susceptibility. However, none of the currently known EPIs have been approved for clinical use, probably due to their toxicity profiles. In the present study, we screened approved drugs for possible efflux pump inhibition. By screening a compound library of approximately 1200 different drugs, we identified nilotinib, a tyrosine kinase inhibitor, as showing the best efflux pump inhibitory activity, with a fractional inhibitory concentration index of 0.1875, indicating synergism with ciprofloxacin, and a minimum effective concentration as low as 0.195 μM. Moreover, at 0.39 μM, nilotinib, in combination with 8 μg/mL of ciprofloxacin, led to a significant reduction in biofilm formation and preformed mature biofilms. This is the first description of an approved drug that can be used as an efflux pump inhibitor and to reduce biofilms formation at clinically achievable concentrations
Ultrastructure of the Membrana Limitans Interna after Dye-Assisted Membrane Peeling
The purpose of this study was to investigate the ultrastructure
of the membrana limitans interna (internal limiting
membrane, ILM) and to evaluate alterations to the retinal cell
layers after membrane peeling with vital dyes. Twenty-five
patients (25 eyes) who underwent macular hole surgery
were included, whereby 12 indocyanine green (ICG)- and 13
brilliant blue G (BBG)-stained ILM were analyzed using light,
transmission electron and scanning electron microscopy.
Retinal cell fragments on the ILM were identified in both
groups using immunohistochemistry. Comparing ICG- and
BBG-stained membranes, larger cellular fragments were observed
at a higher frequency in the BBG group. Thereby, the
findings indicate that ICG permits an enhanced separation
of the ILM from the underlying retina with less mechanical
destruction. A possible explanation might be seen in the
known photosensitivity of ICG, which induces a stiffening
and shrinkage of the ILM but also generates retinal toxic metabolite
Management des Langlebigkeitsrisikos. Proceedings zum 7. FaRis & DAV Symposium am 5.12.2014 in Köln
Die säkulare Sterblichkeitsverbesserung stellt seit langem alle Alterssicherungssysteme vor große Herausforderungen. Nicht zuletzt die Lebensversicherungswirtschaft als klassischer Anbieter von privaten Rentenversicherungen ist davon betroffen. Eine Analyse der Sterblichkeitsentwicklung kann unter ganz unterschiedlichen Blickwinkeln durchgeführt werden; einige wichtige Aspekte wurden beim 7. FaRis & DAV-Symposium vertieft behandelt.The improvement of the mortality is one of the biggest challenges for pension systems. Especially, life insurance as the classical supplier of private annuities is affected by this aspect. An analysis of the development of mortality can be proceeded on the base of different perspectives – some of these have been treated intensively at the 7th FaRis & DAV Symposium
COVID-19 patients share common, corticosteroid-independent features of impaired host immunity to pathogenic molds
Patients suffering from coronavirus disease-2019 (COVID-19) are susceptible to deadly secondary fungal infections such as COVID-19-associated pulmonary aspergillosis and COVID-19-associated mucormycosis. Despite this clinical observation, direct experimental evidence for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-driven alterations of antifungal immunity is scarce. Using an ex-vivo whole blood stimulation assay, we challenged blood from twelve COVID-19 patients with Aspergillus fumigatus and Rhizopus arrhizus antigens and studied the expression of activation, maturation, and exhaustion markers, as well as cytokine secretion. Compared to healthy controls, T-helper cells from COVID-19 patients displayed increased expression levels of the exhaustion marker PD-1 and weakened A. fumigatus - and R. arrhizus -induced activation. While baseline secretion of proinflammatory cytokines was massively elevated, whole blood from COVID-19 patients elicited diminished release of T-cellular (e.g., IFN-γ, IL-2) and innate immune cell-derived (e.g., CXCL9, CXCL10) cytokines in response to A. fumigatus and R. arrhizus antigens. Additionally, samples from COVID-19 patients showed deficient granulocyte activation by mold antigens and reduced fungal killing capacity of neutrophils. These features of weakened anti-mold immune responses were largely decoupled from COVID-19 severity, the time elapsed since diagnosis of COVID-19, and recent corticosteroid uptake, suggesting that impaired anti-mold defense is a common denominator of the underlying SARS-CoV-2 infection. Taken together, these results expand our understanding of the immune predisposition to post-viral mold infections and could inform future studies of immunotherapeutic strategies to prevent and treat fungal superinfections in COVID-19 patients
Evaluation at the Federal University of Applied Adminstrative Sciences
Dulisch, Linssen und Reiter (2001) legten ein umfassendes Evaluationskonzept für die FH Bund vor. In den zehn Fachbereichen und im Zentralbereich der FH Bund erfolgt/e eine Diskussion, Modifikation und konkrete Anpassung an die Belange vor Ort. Dieser Prozess wurde in einer Evaluationtagung an der FH Bund im Juni 2003 gebündelt. Die Tagung zeigte, dass alle Fachbereiche und der Zentralbereich Fortschritte machen, wenn auch in unterschiedlichem Tempo. Dieser Band dokumentiert den Status Quo der Evaluation in den Fachbereichen und dem Zentralbereich und folgt damit § 6 Hochschulrahmengesetz (HRG), wonach die Arbeit der Hochschulen bewertet und das Ergebnis der Bewertung veröffentlicht werden soll. Inhaltsübersicht: - Evaluation an Fachhochschulen - Überblick - Empfehlungen des Benchmarking Clubs - Evaluationstagung der FH Bund 2003 - Zentralbereich - Allgemeine und Innere Verwaltung - Arbeitsverwaltung - Auswärtige Angelegenheiten - Bundesgrenzschutz - Bundeswehrverwaltung - Finanzen - Landwirtschaftliche Sozialversicherung - Öffentliche Sicherheit - Gesamtkonzept - Öffentliche Sicherheit - Abteilung Kriminalpolizei - Sozialversicherung - Wetterdiens
Alteration of contrast enhanced ultrasound (CEUS) of hepatocellular carcinoma in patients with cirrhosis and transjugular intrahepatic portosystemic shunt (TIPS)
Abstract
Transjugular intrahepatic portosystemic shunt (TIPS) can treat portal hypertensive complications and modifies hepatic hemodynamics. Modification of liver perfusion can alter contrast enhancement dynamics of liver nodules. This study investigated the diagnostic performance of contrast-enhanced ultrasound (CEUS) to diagnose hepatocellular carcinoma (HCC) in cirrhosis with TIPS. In this prospective monocentric observational study, CEUS was used to characterize focal liver lesions in patients at risk for HCC with and without TIPS. Times of arterial phase hyperenhancement (APHE) und washout were quantified. Perfusion-index (PI) and resistance-index (RI) of hepatic artery and portal venous flow parameters were measured via doppler ultrasonography. Diagnostic gold standard was MRI/CT or histology. This study included 49 liver lesions [23 TIPS (11 HCC), 26 no TIPS (15 HCC)]. 26 were diagnosed as HCC by gold standard. Sensitivity and specificity of CEUS to diagnose HCC with and without TIPS were 93.3% and 100% vs. 90.9% and 93.3%, respectively. APHE appeared significantly earlier in patients with TIPS compared to patients without TIPS. TIPS significantly accentuates APHE of HCC in CEUS. CEUS has good diagnostic performance for diagnosis of HCC in patients with TIPS
Persister cell phenotypes contribute to poor patient outcomes after neoadjuvant chemotherapy in PDAC
Neoadjuvant chemotherapy can improve the survival of individuals with borderline and unresectable pancreatic ductal adenocarcinoma; however, heterogeneous responses to chemotherapy remain a significant clinical challenge. Here, we performed RNA sequencing (n = 97) and multiplexed immunofluorescence (n = 122) on chemo-naive and postchemotherapy (post-CTX) resected patient samples (chemoradiotherapy excluded) to define the impact of neoadjuvant chemotherapy. Transcriptome analysis combined with high-resolution mapping of whole-tissue sections identified GATA6 (classical), KRT17 (basal-like) and cytochrome P450 3A (CYP3A) coexpressing cells that were preferentially enriched in post-CTX resected samples. The persistence of GATA6hi and KRT17hi cells post-CTX was significantly associated with poor survival after mFOLFIRINOX (mFFX), but not gemcitabine (GEM), treatment. Analysis of organoid models derived from chemo-naive and post-CTX samples demonstrated that CYP3A expression is a predictor of chemotherapy response and that CYP3A-expressing drug detoxification pathways can metabolize the prodrug irinotecan, a constituent of mFFX. These findings identify CYP3A-expressing drug-tolerant cell phenotypes in residual disease that may ultimately inform adjuvant treatment selection
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