Bacterial interference with lactate dehydrogenase assay leads to an underestimation of cytotoxicity

Models to study host-pathogen interactionsin vitroare an important tool for investigating the infectious disease process and evaluating the efficacy of antimicrobial compounds. In these models, the viability of mammalian cells is often determined using the lactate dehydrogenase (LDH) cytotoxicity assay. In the present study we evaluated whether bacteria could interfere with the LDH assay. As a model for host-pathogen interactions, we co-cultured lung epithelial cells with eight bacteria encountered in the lower respiratory tract. We show that LDH activity is affected byPseudomonas aeruginosa, Klebsiella pneumoniae, Stenotrophomonas maltophilia, andStreptococcus pneumoniae, and that this depends on the density of the start inoculum and the duration of infection. Two different mechanisms were discovered through which bacteria interfered with LDH activity, i.e., acidification of the cell culture medium (byK. pneumoniaeandS. pneumoniae) and protease production (byP. aeruginosaandS. maltophilia). In addition, we developed and validated a modified protocol to evaluate cytotoxicity using the LDH assay, where bacterial interference with LDH quantification is avoided

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Kristof Haneca Groene veteranen. Levende getuigen van de eerste wereldbrand. [Green veterans. Living witnesses of the First World War.]In en rond de voormalige frontzone in de Westhoek veroorzaakten niet alleen het oorlogsgeweld, maar ook de grootschalige ontbossing als gevolg van de grote vraag naar constructie- en brandhout, een desolaat en boomloos landschap. Of toch niet helemaal? In de buurt van het voormalige front blijken verrassend genoeg enkele oude bomen wel degelijk de oorlog overleefd te hebben. Kristof Haneca wijst op het bestaan van deze zeldzame reuzen, misschien zelfs talrijker dan gedacht, die in zich letterlijk de wonden dragen van de Eerste Wereldoorlog. Ongeliefd bij houthandelaren door de talrijke inclusies van metaal, zijn ze vandaag de nog levende getuigen van een honderd jaar oud conflict.Eva Bouton, Thomas Coomans en Pascal Delheye De neogotische gymnastiekzaal van de voormalige Rijksnormaalschool te Brugge in cultuurhistorische context. [The Neo-Gothic gymnasium of the former State Teachers College in Bruges in a cultural-historical context.]Vaak ten onrechte vergeleken met de gotische schuur van Ter Doest is de neogotische gymnastiekzaal van de Brugse stadsarchitect Louis Delacenserie niettemin een architecturaal unicum. Gebouwd in 1880-1883 volgens de richtlijnen van het officieel onderwijs, is dit voornamelijk houten interieur nog altijd even indrukwekkend en monumentaal qua afmetingen en materiaalafwerking. Het heeft zijn oorspronkelijke functie al die jaren kunnen behouden en is beschermd als monument. Het toenmalige getouwtrek tussen de Duitse en de Zweedse gymnastiekscholen is af te leiden uit bepaalde keuzes van binnen afwerking en turntoestellen. Eva Bouton, Thomas Coomans en Pascal Delheye bestudeerden dit merkwaardig ontwerp vanuit hun uiteenlopende disciplines en gingen tevens op zoek naar nog andere historische gymzalen uit die periode.Thomas Van Driessche, Geert Bossaert en Herman van den Bossche Het bloeiende grafveld van de Duitse militaire begraafplaats Hooglede bestendigd. [Restoration of the German military cemetery in Hooglede.]De militaire begraafplaatsen in de Westhoek zijn vandaag schreeuwende aanklachten tegen oorlogsgeweld dat zoveel individueel en familiaal leed veroorzaakte. Toch is er verschil in aanpak. De Commonwealth begraafplaatsen benadrukken met hun rechtopstaande individuele melkwitte grafstenen in strak gelid op keurig gemaaide grasvelden de triomf van de overwinnaars. Op de Duitse militaire verzamelbegraafplaatsen uit de jaren 1950 vervangen platte naamstenen en verspreide groepen van 5 kruisen thans de originele individuele gedenktekens. In Hooglede rusten de Duitse gesneuvelden in een bloeiend heideveld onder bomen. Thomas Van Driessche, Geert Bossaert en Herman van den Bossche doen het relaas van het ontstaan, de evolutie en de recente restauratie en herinrichting van deze begraafplaats.Summar

Commensal bacteria of the lung microbiota synergistically inhibit inflammation in a three-dimensional epithelial cell model

Patients with chronic lung disease suffer from persistent inflammation and are typically colonized by pro-inflammatory pathogenic bacteria. Besides these pathogens, a wide variety of commensal species is present in the lower airways but their role in inflammation is unclear. Here, we show that the lung microbiota contains several species able to inhibit activation of the pro-inflammatory NF-κB pathway and production of interleukin 8 (IL-8), triggered by lipopolysaccharide (LPS) or H2O2, in a physiologically relevant three-dimensional (3D) lung epithelial cell model. We demonstrate that the minimal dose needed for anti-inflammatory activity differs between species (with the lowest dose needed for Rothia mucilaginosa), and depends on the type of pro-inflammatory stimulus and read out. Furthermore, we evaluated synergistic activity between pairs of anti-inflammatory bacteria on the inhibition of the NF-κB pathway and IL-8 secretion. Synergistic anti-inflammatory activity was observed for 4/10 tested consortia. These findings indicate that various microbiota members can influence lung inflammation either alone or as a consortium. This information can contribute to a better understanding of the lung microbiota in chronic lung disease development and process, and could open up new avenues for treatment

Exploring deliberate practice in medicine: how do physicians learn in the workplace?

Medical professionals need to keep on learning as part of their everyday work to deliver high-quality health care. Although the importance of physicians’ learning is widely recognized, few studies have investigated how they learn in the workplace. Based on insights from deliberate practice research, this study examined the activities physicians engage in during their work that might further their professional development. As deliberate practice requires a focused effort to improve performance, the study also examined the goals underlying this behaviour. Semi-structured interviews were conducted with 50 internal medicine physicians: 19 residents, 18 internists working at a university hospital, and 13 working at a non-university hospital. The results showed that learning in medical practice was very much embedded in clinical work. Most relevant learning activities were directly related to patient care rather than motivated by competence improvement goals. Advice and feedback were sought when necessary to provide this care. Performance standards were tied to patients’ conditions. The patients encountered and the discussions with colleagues about patients were valued most for professional development, while teaching and updating activities were also valued in this respect. In conclusion, physicians’ learning is largely guided by practical experience rather than deliberately sought. When professionals interact in diagnosing and treating patients to achieve high-quality care, their experiences contribute to expertise development. However, much could be gained from managing learning opportunities more explicitly. We offer suggestions for increasing the focus on learning in medical practice and further research

The interurban DRAG-Spain model: the main factors of influence on road accidents in Spain

This paper presents the results of applying DRAG methodology to the identification of the main factors of influence on the number of injury and fatal accidents occurring on Spain’s interurban network. Nineteen independent variables have been included in the model grouped together under ten categories: exposure, infrastructure, weather, drivers, economic variables, vehicle stock, surveillance, speed and legislative measures. Highly interesting conclusions can be reached from the results on the basis of the different effects of a single variable on each of the accident types according to severity. The greatest influence revealed by the results is exposure, which together with inexperienced drivers, speed and an ageing vehicle stock, have a negative effect, while the increased surveillance on roads, the improvement in the technological features of vehicles and the proportion of high capacity networks have a positive effect, since the results obtained show a significant drop in accidents

Understanding the direct and indirect relations between motivation to participate, goal orientation and the use of self-regulation strategies during a formal training

The current study investigates the direct and indirect relations between motivation to participate, as measured by self-determination theory, goal orientation at the start of the training and use of self-regulation strategies during a formal training. In total, 717 employees completed a questionnaire that consisted of existing scales that were adapted and validated for the context of work-related learning. Results show a positive direct relation between autonomous motivation and a mastery-approach goal orientation, and the use of self-regulation strategies. A significant indirect relation of autonomous motivation through a mastery-approach goal orientation was also found. In addition, results pointed to a negative impact of work-avoidance goal orientation on the use of self-regulation strategies. The latter approach also fully mediated the relation between controlled motivation and a-motivation on the one hand and self-regulated learning on the other. These results point towards the complexity of the relation between motivational dimensions and quality of learning in work-related learning

Demographics, communal cattle dynamics and potential exposure to uncertified meat

To be complete

An exploratory study of group development and team learning

© 2015 Wiley Periodicals, Inc. Teams need to pass through a series of development stages before they can operate effectively, and, in a changing context, it has also been demonstrated that teams need to continue learning in order to remain effective. This article aims to explore the relationship between team development and team learning. In particular, it focuses on when and why basic team learning processes such as sharing information, co-construction, and constructive conflict occur during different phases of development. It can be hypothesized that although each stage of team development is characterized by specific learning tasks, team learning processes occur more in certain stages than in others. The results from a model-based cluster analysis and ANOVA analyses on a sample of 44 professional teams show that team learning occurs more in the later phases of group development due to higher levels of team psychological safety and group potency.status: publishe

The cystic fibrosis lung microenvironment alters antibiotic activity - causes and effects

Chronic airway colonisation by Pseudomonas aeruginosa, a hallmark of cystic fibrosis (CF) lung disease, is associated with increased morbidity and mortality and despite aggressive antibiotic treatment, P. aeruginosa is able to persist in CF airways. In vitro antibiotic susceptibility assays are poor predictors of antibiotic efficacy to treat respiratory tract infections in the CF patient population and the selection of the antibiotic(s) is often made on an empirical base. In the current review, we discuss the factors that are responsible for the discrepancies between antibiotic activity in vitro and clinical efficacy in vivo. We describe how the CF lung microenvironment, shaped by host factors (such as iron, mucus, immune mediators and oxygen availability) and the microbiota, influences antibiotic activity and varies widely between patients. A better understanding of the CF microenvironment and population diversity may thus help improve in vitro antibiotic susceptibility testing and clinical decision making, in turn increasing the success rate of antibiotic treatment