Rasterkraftmikroskopische Untersuchungen von Membraneigenschaften und Membran-Protein Wechselwirkungen

The cell wall of Gram-negative bacteria consists of the cytoplasmic and an additional outer membrane. This outer membrane is an extremely asymmetric bilayer with respect to the lipid composition, the outer leaflet is composed of glycolipids, mainly lipopolysaccharides (LPSs), and the inner leaflet of a phospholipid mixture. When released from bacterial surface into the blood circulation of the host, LPS plays an important role in the pathogenesis and manifestation of gram-negative inflammation, in general, and of septic shock, in particular. In this dissertation, the AFM-technique was used to investigate the properties of membranes, their cooperative processes and lipid-protein interactions with high molecular lateral resolution. Two complementing techniques were used: fluorescence spectroscopy with polarized light to determine phase transition temperatures of lipids and circular dichroism (CD) - spectroscopy to investigate physicochemical properties of the LPS-binding protein (LBP). Experiments were done on reconstituted model membranes - lipid monolayers and -bilayers - which were solid-supported for the AFM-measurements. Two biological questions were important in this dissertation: (i) function of the LPS-layer in Gram-negative bacteria as a permeability barrier and its interaction with antibacterial peptides and (ii) activation of immune cells (mononuclear cells, MNC) of the host immune system by released LPS. To answer the first question, LPS monolayers were prepared. Properties such as topography and phase behaviour and their interaction with antibacterial peptides were investigated. With regard to the second question, the lateral organization of LBP in reconstituted phospholipid membranes mimicking the membrane of MNC was characterized. LBP is involved in the signalling cascade in the activation of MNC and has been described in the literature as a shuttle protein. Here it is shown that LBP has a function as a fusion protein for phospholipid membranes and LPS. Furthermore, force spectroscopy was successfully used for measuring binding forces between LBP and its antibody. This is the first time that a protein was detected in a lipid membrane utilizing antibodies attached to the tip of an AFM-cantilever

Prospective Environmental Life Cycle Assessment of Nanosilver T-Shirts

A cradle-to-grave life cycle assessment (LCA) is performed to compare nanosilver T-shirts with conventional T-shirts with and without biocidal treatment. For nanosilver production and textile incorporation, we investigate two processes: flame spray pyrolysis (FSP) and plasma polymerization with silver co-sputtering (PlaSpu). Prospective environmental impacts due to increased nanosilver T-shirt commercialization are estimated with six scenarios. Results show significant differences in environmental burdens between nanoparticle production technologies: The "cradle-to-gate" climate footprint of the production of a nanosilver T-shirt is 2.70 kg of CO2-equiv (FSP) and 7.67-166 kg of CO2-equiv (PlaSpu, varying maturity stages). Production of conventional T-shirts with and without the biocide triclosan has emissions of 2.55 kg of CO2-equiv (contribution from triclosan insignificant). Consumer behavior considerably affects the environmental impacts during the use phase. Lower washing frequencies can compensate for the increased climate footprint of FSP nanosilver T-shirt production. The toxic releases from washing and disposal in the life cycle of T-shirts appear to be of minor relevance. By contrast, the production phase may be rather significant due to toxic silver emissions at the mining site if high silver quantities are require

Design and implementation of the participatory German network for translational dementia care research (TaNDem): A mixed‐method study on the perspectives of healthcare providers and dementia researchers in dementia care research

Abstract Background Currently, there is a lack of interaction between research and healthcare practice. As a result, research findings reach healthcare practice only late, and topics relevant to practice are often not known in research. Involving people living with dementia (PlwD), their relatives and healthcare providers in dementia care research can accelerate this process. For inclusion, firm and reliable structures are needed, which are to be established with the help of the Translational Network for Dementia Care Research in Germany. However, there is only limited knowledge about the priorities, expectations and conditions of stakeholders (healthcare providers and dementia researchers) for such cooperation within a network. Objectives The aim is to gather stakeholders' views on (i) future research topics to be addressed within the dementia care research network, (ii) the nature of collaboration within the network and (iii) the facilitating and hindering factors for establishing such a network. Methods Within an exploratory sequential mixed‐method study, we interviewed 87 stakeholders within eleven semistructured focus group interviews. The interviews were transcribed, pseudonymized and analyzed using qualitative content analysis. The qualitative data were analyzed with MAXQDA. Based on the qualitative results found in the focus group interviews, a supplementary online questionnaire was developed to prioritise and rank these findings afterwards. Results Stakeholders prioritized a comprehensible transfer of research results into practice, increased involvement of PlwD and their relatives (additionally marginalized groups such as people with a migrant background) in research and exchange between researchers. Cooperation should preferably occur in a regional context with local contacts, and the latest research results should be made available via an online database. The stakeholders' time, finances and human resources should be considered. Conclusion Stakeholders have partly similar preferences and goals for cooperation and involvement, emphasizing that such interaction in a network offers the possibility of long‐term, effective collaboration and added value for practice and research. Patient or Public Contribution For this study, dementia healthcare providers and dementia care researchers were asked about their perspectives. Their involvement is further elucidated in the manuscript text

Participatory development of a framework to actively involve people living with dementia and those from their social network, and healthcare professionals in conducting a systematic review: the DECIDE-SR protocol

Abstract Background Systematic reviews summarize and evaluate relevant studies to contribute to evidence-based practice. Internationally, researchers have reached a consensus that the active involvement of the public leads to better research. Despite this agreement, there are many reviews of research concerning healthcare interventions intended to promote the care of people living with dementia and those from their social network (e.g., close contacts, both family and non-family members) primarily involve only healthcare professionals and other experts. Due to the lack of a dementia-sensitive framework to actively involve people living with dementia and those from their social network, and healthcare professionals as co-researchers in systematic reviews, it is important to develop a framework to inform practice. Methods For this framework development process, we will recruit four people living with dementia and a total of four people from their social network, and three healthcare professionals working in acute or long-term care settings. We will conduct regular meetings with these groups of the public and healthcare professionals to include them in all stages of the systematic review. We will also identify and develop methods necessary to ensure meaningful involvement. The results will be documented and analyzed for the development of a framework. For the planning and preparation for these meetings, as well as the conduct of the meetings themselves, we will be guided by the principles of the INVOLVE approach. In addition, the ACTIVE framework will be used to guide the degree of involvement and the stage in the review process. Discussion We assume that our transparent approach to the development of a framework to support the active involvement of people living with dementia and those from their social network, and healthcare professionals in systematic reviews will serve as an impetus for and provide guidance to other researchers with the goal of increasing researchers’ focus on this topic and facilitating systematic reviews that apply participatory approaches. Trial registration: Trial registration is unnecessary as no intervention study will be conducted

Clinical, methodology, and patient/carer expert advice in pediatric drug development by conect4children

Many medicines are used "off-label" in children outside the terms of the license. Feasible pediatric clinical trials are a challenge to design. Conect4children (c4c) is an Innovative Medicines Initiative project to set up a pan-European pediatric clinical trial network aiming to facilitate the development of new medicines for children. To optimize pediatric trial development by promoting innovative trial design, c4c set up a European multidisciplinary advice service, including the voice of young patients and families, tailored to industry and academia. A network of experts was established to provide multidisciplinary advice to trial sponsors. Experts were selected to join clinical and innovative methodology expert groups. A patient and public involvement (PPI) database, to include the expert opinion of patients and parents/carers was formed. A stepwise process was developed: (1) sponsors contact c4c, (2) scoping interview takes place, (3) ad hoc advice group formed, (5) advice meeting held, and (6) advice report provided. Feedback on the process was collected. Twenty-four clinical and innovative methodology expert groups (>400 experts) and a PPI database of 135 registrants were established. As of September 30, 2022, 36 advice requests were received, with 25 requests completed. Clinical and methodology experts and PPI representatives participated in several advice requests. Sponsors appreciated the advice quality and the multidisciplinary experts from different countries, including experts not known before. Experts and PPI participants were generally satisfied with the process. The c4c project has shown successful proof of concept for a service that presents a new framework to plan innovative and feasible pediatric trials

DNA looping and translocation provide an optimal cleavage mechanism for the type III restriction enzymes

EcoP15I is a type III restriction enzyme that requires two recognition sites in a defined orientation separated by up to 3.5 kbp to efficiently cleave DNA. The mechanism through which site-bound EcoP15I enzymes communicate between the two sites is unclear. Here, we use atomic force microscopy to study EcoP15I–DNA pre-cleavage complexes. From the number and size distribution of loops formed, we conclude that the loops observed do not result from translocation, but are instead formed by a contact between site-bound EcoP15I and a nonspecific region of DNA. This conclusion is confirmed by a theoretical polymer model. It is further shown that translocation must play some role, because when translocation is blocked by a Lac repressor protein, DNA cleavage is similarly blocked. On the basis of these results, we present a model for restriction by type III restriction enzymes and highlight the similarities between this and other classes of restriction enzymes