Interleukin 6 plays a role in the migration of magnetically levitated mesenchymal stem cells spheroids

Mesenchymal stem cells (MSCs) reside quiescently within a specialised ‘niche’ environment in the bone marrow. However, following appropriate signalling cues, MSCs mobilise and migrate out from the niche, typically toward either sites of injury (a regenerative response) or toward primary tumours (an intrinsic homing response, which promotes MSCs as cellular vectors for therapeutic delivery). To date, very little is known about MSC mobilisation. By adopting a 3D MSC niche model, whereby MSC spheroids are cultured within a type I collagen gel, recent studies have highlighted interleukin-6 (IL-6) as a key cytokine involved in MSC migration. Herein, the ability of IL-6 to induce MSC migration was further investigated, and the key matrix metalloproteinases used to effect cell mobilisation were identified. Briefly, the impact of IL-6 on the MSC migration in a two-dimensional model systems was characterised—both visually using an Ibidi chemotaxis plate array (assessing for directional migration) and then via a standard 2D monolayer experiment, where cultured cells were challenged with IL-6 and extracted media tested using an Abcam Human MMP membrane antibody array. The 2D assay displayed a strong migratory response toward IL-6 and analysis of the membrane arrays data showed significant increases of several key MMPs. Both data sets indicated that IL-6 is important in MSC mobilisation and migration. We also investigated the impact of IL-6 induction on MSCs in 3D spheroid culture, serving as a simplistic model of the bone marrow niche, characterised by fluorescently tagged magnetic nanoparticles and identical membrane antibody arrays. An increase in MMP levels secreted by cells treated with 1 ng/mL IL-6 versus control conditions was noted in addition to migration of cells away from the central spheroid mass

Membership and behavior of ultra-low-diversity pathogen communities present in the gut of humans during prolonged critical illness.

UnlabelledWe analyzed the 16S rRNA amplicon composition in fecal samples of selected patients during their prolonged stay in an intensive care unit (ICU) and observed the emergence of ultra-low-diversity communities (1 to 4 bacterial taxa) in 30% of the patients. Bacteria associated with the genera Enterococcus and Staphylococcus and the family Enterobacteriaceae comprised the majority of these communities. The composition of cultured species from stool samples correlated to the 16S rRNA analysis and additionally revealed the emergence of Candida albicans and Candida glabrata in ~75% of cases. Four of 14 ICU patients harbored 2-member pathogen communities consisting of one Candida taxon and one bacterial taxon. Bacterial members displayed a high degree of resistance to multiple antibiotics. The virulence potential of the 2-member communities was examined in C. elegans during nutrient deprivation and exposure to opioids in order to mimic local conditions in the gut during critical illness. Under conditions of nutrient deprivation, the bacterial members attenuated the virulence of fungal members, leading to a "commensal lifestyle." However, exposure to opioids led to a breakdown in this commensalism in 2 of the ultra-low-diversity communities. Application of a novel antivirulence agent (phosphate-polyethylene glycol [Pi-PEG]) that creates local phosphate abundance prevented opioid-induced virulence among these pathogen communities, thus rescuing the commensal lifestyle. To conclude, the gut microflora in critically ill patients can consist of ultra-low-diversity communities of multidrug-resistant pathogenic microbes. Local environmental conditions in gut may direct pathogen communities to adapt to either a commensal style or a pathogenic style.ImportanceDuring critical illness, the normal gut microbiota becomes disrupted in response to host physiologic stress and antibiotic treatment. Here we demonstrate that the community structure of the gut microbiota during prolonged critical illness is dramatically changed such that in many cases only two-member pathogen communities remain. Most of these ultra-low-membership communities display low virulence when grouped together (i.e., a commensal lifestyle); individually, however, they can express highly harmful behaviors (i.e., a pathogenic lifestyle). The commensal lifestyle of the whole community can be shifted to a pathogenic one in response to host factors such as opioids that are released during physiologic stress and critical illness. This shift can be prevented by using compounds such as Pi-PEG15-20 that interrupt bacterial virulence expression. Taking the data together, this report characterizes the plasticity seen with respect to the choice between a commensal lifestyle and a pathogenic lifestyle among ultra-low-diversity pathogen communities that predominate in the gut during critical illness and offers novel strategies for prevention of sepsis

An overview of the regeneration of skeletal muscle

It has only recently been acknowledged widely that mature skeletal muscle has the ability to regenerate, although reports on this phenomenon have existed in the research literature some 40 years. The regenerative events in skeletal muscle include: phagocytosis of cellular and connective tissue debris; revascularization of the lesion; the proliferation of myogenic precursor cells; their differentiation into myoblasts; myoblasts fusion into myotubes; followed by the reestablishment of the nerve supply, and the maturation of myotubes into muscle fibers. The key cell in skeletal muscle regeneration is the satellite cell, which is a reserve myogenic cell situated in between the muscle fiber sarcolemma and its adjacent external lamina. These cells can only by identified by electron microscopy, which makes them very difficult to investigate in detail or quantitatively. However, there is a substantial body of research literature on satellite cells and relevant aspects of their activity are summarized in this review. Satellite cells provide the source of myogenic precursor cells in the regeneration of skeletal muscle, therefore, any factor which stimulates the proliferative activity of satellite cells is very important in enhancing skeletal muscle regeneration. The cellular events in regenerating skeletal muscle closely resemble those which occur in the process of developmental myogenesis, and references to these similarities and differences are briefly reviewed.Biomedical Reviews 1996; 6: 75-81

“Social media makes it inevitable to feel bad about your body”: examining self-presentation and body image of young collegiate females

The current study explored how young females who compete in aesthetic sports adopt self-presentation strategies on social media. Data from semi-structured interviews with 10 collegiate female trampolinists (aged 19–24 years) were analyzed through reflective thematic analysis, and six themes were generated; self-analysis, the best you, emotional consequences, judgment, social media perceptions, and acceptance. Framed around these themes, creative nonfiction techniques were employed to present the results as an ethnodrama. Findings illustrated how participants demonstrated a high need to present their “best self”, as failure to do so results in fear of judgment, extreme self-criticism, and, subsequently, post-prevention. Moreover, participants used upward social comparisons, and when they felt they did not match the ‘thin ideal’, often made negative associations between weight gain and attractiveness. This study contributes to body image literature by demonstrating a more detailed understanding of how social media influences one’s need to alter their self-presentation to fit in with highly pressured societal ideals. In addition, the ethnodrama provides an educational tool to stimulate reflection about the extremity of this issue in today’s modern world

Simulated performance of catch curve methods for estimating total mortality rate

This document has been issued as VIMS Data Report 60 and provides additional simulation results for Smith et al. (2012) published in the North American Journal of Fisheries Management. Catch curve methods are a basic tool of population dynamics for estimating total mortality rate from age composition. There are a number of methodological issues which remain unresolved. Smith et al. (2012) attempts to provide guidelines on the use of these methods based on extensive Monte Carlo simulations. This report presents additional simulation results to supplement the results in the journal article. The estimators, evaluation criteria, simulation procedures, and conditions simulated are given in the journal article

Implementing Ecosystem-Based Management in Canada\u27s Pacific: Developing a Marine Zoning Framework

The Marine Planning Partnership for the North Pacific Coast (MaPP) is a collaborative planning process for coastal and marine areas in the north coast of British Columbia, Canada. MaPP is a co-led partnership between the Province of British Columbia and First Nations governments, represented by the Coastal First Nations-Great Bear Initiative, the North Coast-Skeena First Nations Stewardship Society, and the Nanwakolas Council. Marine plans are being developed for four sub-regions: Haida Gwaii, North Coast, Central Coast, and Northern Vancouver Island. To implement the EBM framework, MaPP designed a Regional Zoning Framework using existing coastal plans, expert advice, and lessons learned from other areas of the world. The three zones are: General Management Zone, Special Management Zone, and Protection Management Zone. The General Management Zone (GMZ) allocates space for a wide range of sustainable marine uses and activities that are compatible with MaPP\u27s ecosystem-based management principles. The Special Management Zone (SMZ) allocates space for high priority and high potential sustainable marine uses and activities, including economic development and cultural uses that require specific environmental conditions or locations. The Protection Management Zone (PMZ) allocates space primarily for conservation purposes, and may protect localized conservation values. The PMZ uses the IUCN categories for marine protected areas and the framework is supported by a number of other tools, including an ecosystem vulnerability matrix, compatible use matrix, activity table, and guidelines for designating zones. In this presentation, we will provide a brief overview of the MaPP, discuss the zoning framework, and describe zoning designations with associated tools in the MaPP study area

Improved method for the scalar control of induction motor drives

Many control schemes have been proposed for induction motors, which are in themselves highly complex non-linear and sometimes internally unstable systems.One of themost accurate control schemes is encodered rotor flux orientated vector control. The advantages and disadvantages of this control are well known and several variations, or reduced vector schemes, have been proposed. This study introduces an improved encoderless scalar, or approximated vector, control method for induction machines which can be applied to general purpose applications that do not require the most precise control. The proposed method overcomes practical difficulties and is suitable for industrial applications. The slip compensated stator flux linkage oriented scheme proposed in this study does not require flux estimation or a speed sensor, only requiring nameplate data, stator current and stator resistance measurement, which can easily be determined at start-up. Simulation and experimental investigations including field weakening operation and the effect of stator resistance variation demonstrate the improved performance of the new scheme compared to previous open loop V/Hz and stator resistive compensated schemes especially at low rotor speeds

Friends, relatives, sanity, and health: The costs of politics

Political scientists have long known that political involvement exacts costs but they have typically defined these costs in relatively narrow, largely economic terms. Though anecdotal evidence suggests that the costs of politics may in fact extend beyond economics to frayed personal relationships, compromised emotional stability, and even physical problems, no systematic evidence on these broader costs exists. We construct and validate batteries of survey items that delineate the physical, social, and emotional costs of political engagement and administer these items to a demographically representative sample of U.S. adults. The results suggest that a large number of Americans believe their physical health has been harmed by their exposure to politics and even more report that politics has resulted in emotional costs and lost friendships