Polyelectrolyte multilayer films with pegylated polypeptides as a new type of anti-microbial protection for biomaterials.

Adhesion of bacteria at the surface of implanted materials is the first step in microbial infection, leading to post-surgical complications. In order to reduce this adhesion, we show that poly(L-lysine)/poly(L-glutamic acid) (PLL/PGA) multilayers ending by several PLL/PGA-g-PEG bilayers can be used, PGA-g-PEG corresponding to PGA grafted by poly(ethylene glycol). Streaming potential and quartz crystal microbalance-dissipation measurements were used to characterize the buildup of these films. The multilayer films terminated by PGA and PGA-g-PEG were found to adsorb an extremely small amount of serum proteins as compared to a bare silica surface but the PGA ending films do not reduce bacterial adhesion. On the other hand, the adhesion of Escherichia coli bacteria is reduced by 72% on films ending by one (PLL/PGA-g-PEG) bilayer and by 92% for films ending by three (PLL/PGA-g-PEG) bilayers compared to bare substrate. Thus, our results show the ability of PGA-g-PEG to be inserted into multilayer films and to drastically reduce both protein adsorption and bacterial adhesion. This kind of anti-adhesive films represents a new and very simple method to coat any type of biomaterials for protection against bacterial adhesion and therefore limiting its pathological consequences.comparative studyevaluation studiesjournal articleresearch support, non-u.s. gov't2004 Mayimporte

Subgraph spotting in graph representations of comic book images

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Graph-based representations are the most powerful data structures for extracting, representing and preserving the structural information of underlying data. Subgraph spotting is an interesting research problem, especially for studying and investigating the structural information based content-based image retrieval (CBIR) and query by example (QBE) in image databases. In this paper we address the problem of lack of freely available ground-truthed datasets for subgraph spotting and present a new dataset for subgraph spotting in graph representations of comic book images (SSGCI) with its ground-truth and evaluation protocol. Experimental results of two state-of-the-art methods of subgraph spotting are presented on the new SSGCI dataset.University of La Rochelle (France

Early-stage development of novel cyclodextrin-siRNA nanocomplexes allows for successful postnebulization transfection of bronchial epithelial cells.

BACKGROUND: Successful delivery of small interfering RNA (siRNA) to the lungs remains hampered by poor intracellular delivery, vector-mediated cytotoxicity, and an inability to withstand nebulization. Recently, a novel cyclodextrin (CD), SC12CDClickpropylamine, consisting of distinct lipophilic and cationic subunits, has been shown to transfect a number of cell types. However, the suitability of this vector for pulmonary siRNA delivery has not been assessed to date. To address this, a series of high-content analysis (HCA) and postnebulization assays were devised to determine the potential for CD-siRNA delivery to the lungs. METHODS: SC12CDClickpropylamine-siRNA mass ratios (MRs) were examined for size and zeta potential. In-depth analysis of nanocomplex uptake and toxicity in Calu-3 bronchial epithelial cells was examined using IN Cell(®) HCA assays. Nebulized SC12CDClickpropylamine nanocomplexes were assessed for volumetric median diameter (VMD) and fine particle fraction (FPF) and compared with saline controls. Finally, postnebulization stability was determined by comparing luciferase knockdown elicited by SC12CDClickpropylamine nanocomplexes before and after nebulization. RESULTS: SC12CDClickpropylamine-siRNA complexation formed cationic nanocomplexes of ≤200 nm in size depending on the medium and led to significantly higher levels of siRNA associated with Calu-3 cells compared with RNAiFect-siRNA-treated cells at all MRs (p CONCLUSIONS: SC12CDClickpropylamine nanocomplexes can be effectively nebulized for pulmonary delivery of siRNA using Aeroneb technology to mediate knockdown in airway cells. To the best of our knowledge, this is the first study examining the suitability of SC12CDClickpropylamine-siRNA nanocomplexes for pulmonary delivery. Furthermore, this work provides an integrated nanomedicine-device combination for future in vitro and in vivo preclinical and clinical studies of inhaled siRNA therapeutics

Tackling the Mouse‐on‐Mouse Problem in Cochlear Immunofluorescence: A Simple Double‐Blocking Protocol for Immunofluorescent Labeling of Murine Cochlear Sections with Primary Mouse Antibodies

The mouse is the most widely used animal model in hearing research. Immunohistochemistry and immunofluorescent staining of murine cochlear sections have, thus, remained a backbone of inner ear research. Since many primary antibodies are raised in mouse, the problem of "mouse-on-mouse" background arises due to the interaction between the anti-mouse secondary antibody and the native mouse immunoglobulins. Here, we describe the pattern of mouse-on-mouse background fluorescence in sections of the postnatal mouse cochlea. Furthermore, we describe a simple double-blocking immunofluorescence protocol to label mouse cochlear cryosections. The protocol contains a conventional blocking step with serum, and an additional blocking step with a commercially available anti-mouse IgG blocking reagent. This blocking technique virtually eliminates the "mouse-on-mouse" background in murine cochlear sections, while adding only a little time to the staining protocol. We provide detailed instructions and practical tips for tissue harvesting, processing, and immunofluorescence-labeling. Further protocol modifications are described, to shorten the duration of the protocol, based on the primary antibody incubation temperature. Finally, we demonstrate examples of immunofluorescence staining performed using different incubation times and various incubation temperatures with a commercially available mouse monoclonal primary antibody

Initial impacts of the COVID-19 pandemic on Australian fisheries production, research organisations and assessment: shocks, responses and implications for decision support and resilience

Australia’s fisheries have experience in responding individually to specific shocks to stock levels (for example, marine heatwaves, floods) and markets (for example, global financial crisis, food safety access barriers). The COVID-19 pandemic was, however, novel in triggering a series of systemic shocks and disruptions to the activities and operating conditions for all Australia’s commercial fisheries sectors including those of the research agencies that provide the information needed for their sustainable management. While these disruptions have a single root cause—the public health impacts and containment responses to the COVID-19 pandemic—their transmission and effects have been varied. We examine both the impacts on Australian fisheries triggered by measures introduced by governments both internationally and domestically in response to the COVID-19 pandemic outbreak, and the countermeasures introduced to support continuity in fisheries and aquaculture production and supply chains. Impacts on fisheries production are identified by comparing annual and monthly catch data for Australia’s commercial fisheries in 2020 with averages for the last 4–5 years. We combine this with a survey of the short-term disruption to and impacts on research organisations engaged in fisheries monitoring and assessment and the adaptive measures they deployed. The dominant impact identified was triggered by containment measures both within Australia and in export receiving countries which led to loss of export markets and domestic dine-in markets for live or fresh seafood. The most heavily impact fisheries included lobster and abalone (exported live) and specific finfishes (exported fresh or sold live domestically), which experienced short-term reductions in both production and price. At the same time, improved prices and demand for seafood sold into domestic retail channels were observed. The impacts observed were both a function of the disruptions due to the COVID-19 pandemic and the countermeasures and support programs introduced by various national and state-level governments across Australia to at least partly mitigate negative impacts on harvesting activities and supply chains. These included protecting fisheries activities from specific restrictive COVID-19 containment measures, pro-actively re-establishing freight links, supporting quota roll-overs, and introducing wage and businesses support packages. Fisheries research organisations were impacted to various degrees, largely determined by the extent to which their field monitoring activities were protected from specific restrictive COVID-19 containment measures by their state-level governments. Responses of these organisations included reducing fisheries dependent and independent data collection as required while developing strategies to continue to provide assessment services, including opportunistic innovations to harvest data from new data sources. Observed short run impacts of the COVID-19 pandemic outbreak has emphasised both the vulnerability of fisheries dependent on export markets, live or fresh markets, and long supply chains and the resilience of fisheries research programs. We suggest that further and more comprehensive analysis over a longer time period of the long-run impacts of subsequent waves of variants, extended pandemic containment measures, autonomous and planned adaptive responses would be beneficial for the development of more effective counter measures for when the next major external shock affects Australian fisheries

Nijmegen paediatric CDG rating scale: a novel tool to assess disease progression

Congenital disorders of glycosylation (CDG) are a group of clinically heterogeneous inborn errors of metabolism. At present, treatment is available for only one CDG, but potential treatments for the other CDG are on the horizon. It will be vitally important in clinical trials of such agents to have a clear understanding of both the natural history of CDG and the corresponding burden of disability suffered by patients. To date, no multicentre studies have attempted to document the natural history of CDG. This is in part due to the lack of a reliable assessment tool to score CDG’s diverse clinical spectrum. Based on our earlier experience evaluating disease progression in disorders of oxidative phosphorylation, we developed a practical and semi-quantitative rating scale for children with CDG. The Nijmegen Paediatric CDG Rating Scale (NPCRS) has been validated in 12 children, offering a tool to objectively monitor disease progression. We undertook a successful trial of the NPCRS with a collaboration of nine experienced physicians, using video records of physical and neurological examination of patients. The use of NPCRS can facilitate both longitudinal and natural history studies that will be essential for future interventions