Suchergebnisse

4. Marsilius-Vorlesung am 4. Februar 2010 in der Alten Aula der Universität Heidelberg Teil 1: Begrüßung: Prof. Dr. Bernhard Eitel, Rektor der Universität Heidelberg Teil 2: Einführung: Prof. Dr. Hans-Georg Kräusslich, Universitätsklinikum Heidelberg Teil 3: Vorlesung "Wachstum in Natur und Kultur": Prof. Dr. Christiane Nüsslein-Volhard, Max-Planck-Institut für Entwicklungsbiologie Tübingen Nobelpreisträgerin Prof. Dr. Christiane Nüsslein-Volhard ist am 4. Februar 2010 zu Gast an der Universität Heidelberg. Die renommierte Molekularbiologin, die 1995 die hohe Wissenschaftsauszeichnung in der Medizin erhielt, konnte als Referentin für die Marsilius-Vorlesung gewonnen werden. In ihrem Vortrag wird sich die Wissenschaftlerin vom Max-Planck-Institut für Entwicklungsbiologie in Tübingen mit dem Thema "Wachstum in Natur und Kultur" auseinandersetzen. Der Begriff "Wachstum" weckt einerseits Hoffnungen auf mehr Wohlstand und sozialen Aufstieg. Andererseits wird er auch mit einem der größten Probleme der Menschheit und dessen Auswirkungen in Verbindung gebracht, der rasanten Zunahme der Bevölkerung. Sie gehört nicht nur zu den wichtigsten Ursachen des Klimawandels, sondern erzeugt darüber hinaus auch Probleme wie Hungersnöte, Armut und Flüchtlingswellen. In ihrem Vortrag erläutert Prof. Nüsslein-Volhard grundlegende Mechanismen des Wachstums in der Natur und zeigt auf, wie die Menschheit aufgrund kultureller Fähigkeiten natürliche Wachstums- und Zerfallsprozesse beeinflussen konnte. Sie verdeutlicht dabei auch, welche Bedeutung die Kultivierung und Veränderung von Pflanzen und Tieren für die Wachstumsmöglichkeiten der Menschheit hatten. In diesem Zusammenhang geht die Wissenschaftlerin zugleich auf Fragen der grünen Gentechnik ein. Christiane Nüsslein-Volhard ist seit 1985 Direktorin am Max-Planck-Institut für Entwicklungsbiologie in Tübingen. Ihre Forschungen befassen sich mit der genetischen und molekularen Analyse der embryonalen Entwicklung bei Tieren. Für die Identifizierung von Genen, die die Entwicklung von Tier und Mensch steuern, sowie den Nachweis von gestaltbildenden Gradienten im Fliegenembryo hat sie zahlreiche Auszeichnungen, Ehrungen und Preise erhalten. Von 2001 bis 2006 gehörte sie dem Nationalen Ethikrat der Bundesregierung an. Seit 2005 ist sie Mitglied im Wissenschaftlichen Rat des European Research Council (ERC) der Europäischen Union. 2004 gründete sie die Christiane Nüsslein-Volhard Stiftung zur Unterstützung junger Wissenschaftlerinnen mit Kindern. Das Marsilius-Kolleg ist ein zentraler Baustein im Zukunftskonzept der Universität Heidelberg. Die Arbeit des Kollegs ist darauf ausgerichtet, ausgewählte Forscherinnen und Forscher aus unterschiedlichen Wissenschaftskulturen zusammenzuführen und damit den forschungsbezogenen Dialog zwischen Geistes-, Rechts- und Sozialwissenschaften einerseits und den Natur- und Lebenswissenschaften andererseits zu fördern. Die Marsilius-Vorlesungen richten sich an die breite Öffentlichkeit.

BackgroundWe wanted to explore to what extent environmental exposure to immune stimulants, which is expected to be more present in rural than in urban settings, influences T cell activation and maturation in healthy and in HIV‐1‐infected individuals in Burkina Faso in west Africa.MethodsThe proportion of circulating naïve T cells and the expression of the T cell activation markers, CD95 and CD38, were analyzed by immunophenotyping and three‐colour flow cytometry in 63 healthy individuals and 137 treatment‐naïve HIV‐1‐infected subjects from Ouagadougou (urban setting) and 26 healthy adults and 61 treatment‐naïve patients from Nouna (rural).ResultsA slightly higher activation level of CD4+ and CD8+ peripheral blood T cells was seen in healthy adults living in Nouna than in those living in Ouagadougou. The percentages of naïve CD45RAbright CCR7+ T cells were not significantly different between both study sites. Taking into consideration that relatively more HIV‐1‐infected patients in Nouna were in an advanced disease stage, no relevant differences were seen in T cell activation and maturation between patients at both study sites. As expected, the percentage of CD95+ CD4+ and CD38+ CD8+ T cells and the respective antigen density on these cells was significantly higher in patients than in controls in both settings. The percentage of naïve CD8+ T cells was lower in HIV‐1‐infected subjects than in healthy controls irrespective of the study site, while a lower proportion of naïve CD4+ T cells in patients compared with controls was seen only in Nouna.ConclusionsEnvironmentally triggered immune activation may contribute to the increased expression of the activation markers CD95 and CD38 on peripheral blood T cells from healthy adults living in rural versus urban settings in Burkina Faso. T cell activation is further increased in HIV‐1‐infected individuals due to T cell loss and high plasma viral load levels. The observed variations in T cell activation levels or the proportion of naïve T cells in our study patients, however, are not explained by differences in CD4+ T cell counts or HIV‐1 plasma viral load levels alone.

HIV‐1 entry requires the redistribution of envelope glycoproteins (Env) into a cluster and the presence of cholesterol (chol) in the viral membrane. However, the molecular mechanisms underlying the specific role of chol in infectivity and the driving force behind Env clustering remain unknown. Here, gp41 is demonstrated to directly interact with chol in the viral membrane via residues 751–854 in the cytoplasmic tail (CT751–854). Super‐resolution stimulated emission depletion (STED) nanoscopy analysis of Env distribution further demonstrates that both truncation of gp41 CT751–854 and depletion of chol leads to dispersion of Env clusters in the viral membrane and inhibition of virus entry. This work reveals a direct interaction of gp41 CT with chol and indicates that this interaction is an important orchestrator of Env clustering. ; The authors are grateful to Barbara Müller, N. Landau, and Tom Hope for providing the plasmids pCHIV and pCAGGS NL4‐3 Env, pMM310, and peGFP‐Vpr, respectively. Proteomic analysis was performed by the SGIKER service of the University of the Basque Country. The authors would like to thank Advanced Light Microscopy Unit at the Centre for Genomic Regulation (CRG), Barcelona, Spain for the access to Leica STED microscope. The following reagents were obtained through the NIH AIDS Reagent Program (Division of NIAID, NIH): Anti‐HIV‐1 gp41 Hybridome (Chessie 8) (Cat# 526) from Dr. George Lewis; Antiviral bicyclam JM‐2987 (hydrobromide salt of AMD‐3100) from NIAID, DAIDS (cat# 8128). This project was supported by the Basque Government (grant number IT1264‐19 to M.L. and F.‐X.C.) and the Spanish Ministry of Science, Innovation, and Universities (BFU‐2015‐68981‐P). This work was supported in part by the Fundación Biofísica Bizkaia and the Basque Excellence Research Centre (BERC) program of the Basque Government. J.A.N.‐G. was supported by a FI predoctoral fellowship from the Basque Government and currently by Fundación Biofísica Bizkaia. A.A. was supported by Fundación Biofísica Bizkaia. S.O. was supported by an IKASIKER fellowship from the Basque Government. J.C. was supported by European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No. 793830. H.G.‐K. was supported by a grant from the Deutsche Forschungsgemeischaft within TRR86. ; Peer reviewed

Antibiotika-resistente Bakterien und fehlende Antibiotika gefährden zunehmend die erfolgreiche Behandlung von bakteriellen Infektionskrankheiten. Diese Stellungnahme beschreibt den unbefriedigenden Status Quo in der Entwicklung neuer Antibiotika und gibt auf breiter Basis Empfehlungen für Lösungsansätze in Forschung, Politik und Gesellschaft.

Importance School and daycare closures were enforced as measures to confine the novel coronavirus disease 2019 (COVID-19) pandemic, based on the assumption that young children may play a key role in severe acute respiratory coronavirus 2 (SARS-CoV-2) spread. Given the grave consequences of contact restrictions for children, a better understanding of their contribution to the COVID-19 pandemic is of great importance. Objective To describe the rate of SARS-CoV-2 infections and the seroprevalence of SARS-CoV-2 antibodies in children aged 1 to 10 years, compared with a corresponding parent of each child, in a population-based sample. Design, Setting, and Participants This large-scale, multicenter, cross-sectional investigation (the COVID-19 BaWü study) enrolled children aged 1 to 10 years and a corresponding parent between April 22 and May 15, 2020, in southwest Germany. Exposures Potential exposure to SARS-CoV-2. Main Outcomes and Measures The main outcomes were infection and seroprevalence of SARS-CoV-2. Participants were tested for SARS-CoV-2 RNA from nasopharyngeal swabs by reverse transcription–polymerase chain reaction and SARS-CoV-2 specific IgG antibodies in serum by enzyme-linked immunosorbent assays and immunofluorescence tests. Discordant results were clarified by electrochemiluminescence immunoassays, a second enzyme-linked immunosorbent assay, or an in-house Luminex-based assay. Results This study included 4964 participants: 2482 children (median age, 6 [range, 1-10] years; 1265 boys [51.0%]) and 2482 parents (median age, 40 [range, 23-66] years; 615 men [24.8%]). Two participants (0.04%) tested positive for SARS-CoV-2 RNA. The estimated SARS-CoV-2 seroprevalence was low in parents (1.8% [95% CI, 1.2–2.4%]) and 3-fold lower in children (0.6% [95% CI, 0.3-1.0%]). Among 56 families with at least 1 child or parent with seropositivity, the combination of a parent with seropositivity and a corresponding child with seronegativity was 4.3 (95% CI, 1.19-15.52) times higher than the combination of a parent who was seronegative and a corresponding child with seropositivity. We observed virus-neutralizing activity for 66 of 70 IgG-positive serum samples (94.3%). Conclusions and Relevance In this cross-sectional study, the spread of SARS-CoV-2 infection during a period of lockdown in southwest Germany was particularly low in children aged 1 to 10 years. Accordingly, it is unlikely that children have boosted the pandemic. This SARS-CoV-2 prevalence study, which appears to be the largest focusing on children, is instructive for how ad hoc mass testing provides the basis for rational political decision-making in a pandemic.

Background: To achieve higher effectiveness in population-based SARS-CoV-2 surveillance and to reliably predict the course of an outbreak, screening, and monitoring of infected individuals without major symptoms (about 40% of the population) will be necessary. While current testing capacities are also used to identify such asymptomatic cases, this rather passive approach is not suitable in generating reliable population-based estimates of the prevalence of asymptomatic carriers to allow any dependable predictions on the course of the pandemic. Methods: This trial implements a two-factorial, randomized, controlled, multi-arm, prospective, interventional, single-blinded design with cluster sampling and four study arms, each representing a different SARS-CoV-2 testing and surveillance strategy based on individuals' self-collection of saliva samples which are then sent to and analyzed by a laboratory. The targeted sample size for the trial is 10,000 saliva samples equally allocated to the four study arms (2500 participants per arm). Strategies differ with respect to tested population groups (individuals vs. all household members) and testing approach (without vs. with pre-screening survey). The trial is complemented by an economic evaluation and qualitative assessment of user experiences. Primary outcomes include costs per completely screened person, costs per positive case, positive detection rate, and precision of positive detection rate. Discussion: Systems for active surveillance of the general population will gain more importance in the context of pandemics and related disease prevention efforts. The pandemic parameters derived from such active surveillance with routine population monitoring therefore not only enable a prospective assessment of the short-term course of a pandemic, but also a more targeted and thus more effective use of local and short-term countermeasures. Trial registration: ClinicalTrials.gov DRKS00023271. Registered November 30, 2020, with the German Clinical Trials Register (Deutsches Register Klinischer Studien)