Pseudotumoral tracheobronchial amyloidosis mimicking asthma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Tracheobronchial amyloidosis is an uncommon localized form of amyloidosis that can simulate a tracheal tumor. Clinical signs are not specific and the diagnosis is rarely given before performing a bronchoscopy with multiples biopsies.</p> <p>Case presentation</p> <p>We report the case of a 60-year-old Moroccan woman, complaining of dyspnea and wheezing for three years, who was treated at our institution for management of severe asthma. A bronchoscopy revealed a tumor formation of her trachea; multiples biopsies were performed and a diagnosis made of amyloid light-chain amyloidosis. She successfully received an endoscopic resection.</p> <p>Conclusion</p> <p>This case highlights the importance of routinely carrying out an endoscopy in any patient complaining of atypical bronchial symptoms or with uncontrolled asthma. Tracheal amyloidosis is a rare disease, confirmed by histological examination of bronchial biopsies, and the treatment of choice is based on the bronchoscopic resection.</p

Rationality versus reality: the challenges of evidence-based decision making for health policy makers

<p>Abstract</p> <p>Background</p> <p>Current healthcare systems have extended the evidence-based medicine (EBM) approach to health policy and delivery decisions, such as access-to-care, healthcare funding and health program continuance, through attempts to integrate valid and reliable evidence into the decision making process. These policy decisions have major impacts on society and have high personal and financial costs associated with those decisions. Decision models such as these function under a shared assumption of rational choice and utility maximization in the decision-making process.</p> <p>Discussion</p> <p>We contend that health policy decision makers are generally unable to attain the basic goals of evidence-based decision making (EBDM) and evidence-based policy making (EBPM) because humans make decisions with their naturally limited, faulty, and biased decision-making processes. A cognitive information processing framework is presented to support this argument, and subtle cognitive processing mechanisms are introduced to support the focal thesis: health policy makers' decisions are influenced by the subjective manner in which they individually process decision-relevant information rather than on the objective merits of the evidence alone. As such, subsequent health policy decisions do not necessarily achieve the goals of evidence-based policy making, such as maximizing health outcomes for society based on valid and reliable research evidence.</p> <p>Summary</p> <p>In this era of increasing adoption of evidence-based healthcare models, the rational choice, utility maximizing assumptions in EBDM and EBPM, must be critically evaluated to ensure effective and high-quality health policy decisions. The cognitive information processing framework presented here will aid health policy decision makers by identifying how their decisions might be subtly influenced by non-rational factors. In this paper, we identify some of the biases and potential intervention points and provide some initial suggestions about how the EBDM/EBPM process can be improved.</p

Subinhibitory Arsenite Concentrations Lead to Population Dispersal in Thiomonas sp.

Biofilms represent the most common microbial lifestyle, allowing the survival of microbial populations exposed to harsh environmental conditions. Here, we show that the biofilm development of a bacterial species belonging to the Thiomonas genus, frequently found in arsenic polluted sites and playing a key role in arsenic natural remediation, is markedly modified when exposed to subinhibitory doses of this toxic element. Indeed, arsenite [As(III)] exposure led to a considerable impact on biofilm maturation by strongly increasing the extracellular matrix synthesis and by promoting significant cell death and lysis within microcolonies. These events were followed by the development of complex 3D-biofilm structures and subsequently by the dispersal of remobilized cells observed inside the previously formed hollow voids. Our results demonstrate that this biofilm community responds to arsenite stress in a multimodal way, enhancing both survival and dispersal. Addressing this complex bacterial response to As(III) stress, which might be used by other microorganisms under various adverse conditions, may be essential to understand how Thiomonas strains persist in extreme environments

Talking about smoking cessation with post-natal women: Exploring midwives’ experiences

This study explored midwives’ experiences of talking to post-natal women about smoking cessation. Face-to-face semi structured interviews were held with seven midwives based in the UK. Thematic analysis identified themes which provided understanding as to factors determining discussion of smoking cessation. Six themes were identified which were Post-natal Women Factors, Midwife Factors, Providing Information, Involving Others, Priorities, and Whole Family Approach. Implications for midwives working with post-natal women are discussed, including the need to increase the involvement of other healthcare professionals in supporting post-natal women to stop smoking

A mathematical model of quorum sensing regulated EPS production in biofilm communities

<p>Abstract</p> <p>Background</p> <p>Biofilms are microbial communities encased in a layer of extracellular polymeric substances (EPS). The EPS matrix provides several functional purposes for the biofilm, such as protecting bacteria from environmental stresses, and providing mechanical stability. Quorum sensing is a cell-cell communication mechanism used by several bacterial taxa to coordinate gene expression and behaviour in groups, based on population densities.</p> <p>Model</p> <p>We mathematically model quorum sensing and EPS production in a growing biofilm under various environmental conditions, to study how a developing biofilm impacts quorum sensing, and conversely, how a biofilm is affected by quorum sensing-regulated EPS production. We investigate circumstances when using quorum-sensing regulated EPS production is a beneficial strategy for biofilm cells.</p> <p>Results</p> <p>We find that biofilms that use quorum sensing to induce increased EPS production do not obtain the high cell populations of low-EPS producers, but can rapidly increase their volume to parallel high-EPS producers. Quorum sensing-induced EPS production allows a biofilm to switch behaviours, from a colonization mode (with an optimized growth rate), to a protection mode.</p> <p>Conclusions</p> <p>A biofilm will benefit from using quorum sensing-induced EPS production if bacteria cells have the objective of acquiring a thick, protective layer of EPS, or if they wish to clog their environment with biomass as a means of securing nutrient supply and outcompeting other colonies in the channel, of their own or a different species.</p

Lessons learned from the London Exercise and Pregnant (LEAP) Smokers randomised controlled trial process evaluation : implications for the design of physical activity for smoking cessation interventions during pregnancy

BACKGROUND: The challenges of delivering interventions for pregnant smokers have been poorly documented. Also, the process of promoting a physical activity intervention for pregnant smokers has not been previously recorded. This study describes the experiences of researchers conducting a randomised controlled trial of physical activity as an aid to smoking cessation during pregnancy and explores how the effectiveness of future interventions could be improved. METHODS: Two focus groups, with independent facilitators, were conducted with six researchers who had enrolled pregnant smokers in the LEAP trial, provided the interventions, and administered the research measures. Topics included recruitment, retention and how the physical activity intervention for pregnant smokers was delivered and how it was adapted when necessary to suit the women. The focus groups were audio-recorded, transcribed verbatim and subjected to thematic analysis. RESULTS: Five themes emerged related to barriers or enablers to intervention delivery: (1) nature of the intervention; (2) personal characteristics of trial participants; (3) practical issues; (4) researchers' engagement with participants; (5) training and support needs. Researchers perceived that participants may have been deterred by the intensive and generic nature of the intervention and the need to simultaneously quit smoking and increase physical activity. Women also appeared hampered by pregnancy ailments, social deprivation, and poor mental health. Researchers observed that their status as health professionals was valued by participants but it was challenging to maintain contact with participants. Training and support needs were identified for dealing with pregnant teenagers, participants' friends and family, and post-natal return to smoking. CONCLUSIONS: Future exercise interventions for smoking cessation in pregnancy may benefit by increased tailoring of the intervention to the characteristics of the women, including their psychological profile, socio-economic background, pregnancy ailments and exercise preferences. Delivering an effective physical activity intervention for smoking cessation in pregnancy may require more comprehensive training for those delivering the intervention, particularly with regard to dealing with teenage smokers and smokers' friends and family, as well as for avoiding post-natal return to smoking. TRIAL REGISTRATION: ISRCTN48600346 , date of registration: 21/07/2008

The Relative Importance of Topography and RGD Ligand Density for Endothelial Cell Adhesion

The morphology and function of endothelial cells depends on the physical and chemical characteristics of the extracellular environment. Here, we designed silicon surfaces on which topographical features and surface densities of the integrin binding peptide arginine-glycine-aspartic acid (RGD) could be independently controlled. We used these surfaces to investigate the relative importance of the surface chemistry of ligand presentation versus surface topography in endothelial cell adhesion. We compared cell adhesion, spreading and migration on surfaces with nano- to micro-scaled pyramids and average densities of 6×102–6×1011 RGD/mm2. We found that fewer cells adhered onto rough than flat surfaces and that the optimal average RGD density for cell adhesion was 6×105 RGD/mm2 on flat surfaces and substrata with nano-scaled roughness. Only on surfaces with micro-scaled pyramids did the topography hinder cell migration and a lower average RGD density was optimal for adhesion. In contrast, cell spreading was greatest on surfaces with 6×108 RGD/mm2 irrespectively of presence of feature and their size. In summary, our data suggest that the size of pyramids predominately control the number of endothelial cells that adhere to the substratum but the average RGD density governs the degree of cell spreading and length of focal adhesion within adherent cells. The data points towards a two-step model of cell adhesion: the initial contact of cells with a substratum may be guided by the topography while the engagement of cell surface receptors is predominately controlled by the surface chemistry