The Blister Score: A Novel, Externally Validated Tool for Predicting Cardiac Implantable Electronic Device Infections, and Its Cost-utility Implications for Antimicrobial Envelope Use.

Background: Antimicrobial envelopes reduce the incidence of cardiac implantable electronic device (CIED) infections, but their cost restricts routine use in the UK. Risk scoring could help identify which patients would most benefit from this technology. Methods: A novel risk score (BLISTER) was derived from multivariate analysis of factors associated with CIED infection. Diagnostic utility was assessed against the existing PADIT score in both standard and high-risk external validation cohorts, and cost-utility models examined different BLISTER and PADIT score thresholds for TYRXTM antimicrobial envelope (AE) allocation. Results: In a derivation cohort (n=7,383), CIED infection occurred in 59 individuals within 12 months of a procedure (event rate: 0.8%). In addition to the PADIT score constituents, lead extraction (HR 3.3 (1.9-6.1), p50mg/l (HR 3.0 (1.4-6.4), p=0.005), re-intervention within two years (HR 10.1 (5.6-17.9), p<0.0001), and top-quartile procedure duration (HR 2.6 (1.6-4.1), p=0.001) were independent predictors of infection. The BLISTER score demonstrated superior discriminative performance versus PADIT in the standard-risk (n=2,854, event rate: 0.8%, AUC 0.82 vs 0.71, p=0.001) and high-risk validation cohorts (n=1,961, event rate: 2.0%, AUC 0.77 vs 0.69, p=0.001), and in all patients (n=12,198, event rate: 1%, AUC 0.8 vs 0.75, p=0.002). In decision-analytic modelling, the optimum scenario assigned AEs to patients with BLISTER scores ≥ 6 (10.8%), delivering a significant reduction in infections (relative risk reduction: 30%, p=0.036) within the NICE cost-utility thresholds (ICER: ￡18,446). Conclusions: The BLISTER score (https://qxmd.com/calculate/calculator_876/the-blister-score-for-cied-infection) was a valid predictor of CIED infection, and could facilitate cost-effective AE allocation to high-risk patients

Sialidases Affect the Host Cell Adherence and Epsilon Toxin-Induced Cytotoxicity of Clostridium perfringens Type D Strain CN3718

Clostridium perfringens type B or D isolates, which cause enterotoxemias or enteritis in livestock, produce epsilon toxin (ETX). ETX is exceptionally potent, earning it a listing as a CDC class B select toxin. Most C. perfringens strains also express up to three different sialidases, although the possible contributions of those enzymes to type B or D pathogenesis remain unclear. Type D isolate CN3718 was found to carry two genes (nanI and nanJ) encoding secreted sialidases and one gene (nanH) encoding a cytoplasmic sialidase. Construction in CN3718 of single nanI, nanJ and nanH null mutants, as well as a nanI/nanJ double null mutant and a triple sialidase null mutant, identified NanI as the major secreted sialidase of this strain. Pretreating MDCK cells with NanI sialidase, or with culture supernatants of BMC206 (an isogenic CN3718 etx null mutant that still produces sialidases) enhanced the subsequent binding and cytotoxic effects of purified ETX. Complementation of BMC207 (an etx/nanH/nanI/nanJ null mutant) showed this effect is mainly attributable to NanI production. Contact between BMC206 and certain mammalian cells (e.g., enterocyte-like Caco-2 cells) resulted in more rapid sialidase production and this effect involved increased transcription of BMC206 nanI gene. BMC206 was shown to adhere to some (e.g. Caco-2 cells), but not all mammalian cells, and this effect was dependent upon sialidase, particularly NanI, expression. Finally, the sialidase activity of NanI (but not NanJ or NanH) could be enhanced by trypsin. Collectively these in vitro findings suggest that, during type D disease originating in the intestines, trypsin may activate NanI, which (in turn) could contribute to intestinal colonization by C. perfringens type D isolates and also increase ETX action

A Novel Non-Lens βγ−Crystallin and Trefoil Factor Complex from Amphibian Skin and Its Functional Implications

In vertebrates, non-lens betagamma-crystallins are widely expressed in various tissues, but their functions are unknown. The molecular mechanisms of trefoil factors, initiators of mucosal healing and being greatly involved in tumorigenesis, have remained elusive.A naturally existing 72-kDa complex of non-lens betagamma-crystallin (alpha-subunit) and trefoil factor (beta-subunit), named betagamma-CAT, was identified from frog Bombina maxima skin secretions. Its alpha-subunit and beta-subunit (containing three trefoil factor domains), with a non-covalently linked form of alphabeta(2), show significant sequence homology to ep37 proteins, a group of non-lens betagamma-crystallins identified in newt Cynops pyrrhogaster and mammalian trefoil factors, respectively. betagamma-CAT showed potent hemolytic activity on mammalian erythrocytes. The specific antiserum against each subunit was able to neutralize its hemolytic activity, indicating that the two subunits are functionally associated. betagamma-CAT formed membrane pores with a functional diameter about 2.0 nm, leading to K(+) efflux and colloid-osmotic hemolysis. High molecular weight SDS-stable oligomers (>240-kDa) were detected by antibodies against the alpha-subunit with Western blotting. Furthermore, betagamma-CAT showed multiple cellular effects on human umbilical vein endothelial cells. Low dosages of betagamma-CAT (25-50 pM) were able to stimulate cell migration and wound healing. At high concentrations, it induced cell detachment (EC(50) 10 nM) and apoptosis. betagamma-CAT was rapidly endocytosed via intracellular vacuole formation. Under confocal microscope, some of the vacuoles were translocated to nucleus and partially fused with nuclear membrane. Bafilomycin A1 (a specific inhibitor of the vacuolar-type ATPase) and nocodazole (an agent of microtuble depolymerizing), while inhibited betagamma-CAT induced vacuole formation, significantly inhibited betagamma-CAT induced cell detachment, suggesting that betagamma-CAT endocytosis is important for its activities.These findings illustrate novel cellular functions of non-lens betagamma-cyrstallins and action mechanism via association with trefoil factors, serving as clues for investigating the possible occurrence of similar molecules and action mechanisms in mammals

Social enterprise and ethnic minorities: exploring the consequences of the evolving British policy agenda

Recent years have seen successive British governments move social enterprise centre stage as a policy construct. Yet there remains little understanding as to whether this policy direction provides new opportunities for engagement for migrant and ethnic minority groups or acts to reinforce past processes of exclusion. We address this issue by examining the nature and extent of migrant and ethnic minorities’ involvement in social enterprise activity and the resulting implications for policy and practice. Through original empirical analysis of ethnic minority third sector organisations in East London, results are presented in relation to the challenges of defining and measuring this arena of activity, the nature of the current transition towards social enterprise forms, and the extent of engagement in the policy process. We conclude that the narrow arena of action for social enterprise activity as promoted within the current policy discourse provides little scope for engagement for the majority of small-scale ethnic minority organisations

The measurement and prediction of conditions within indoor microenvironments

Biocontaminants, such as dust mites and microfungi, can live in building habitats with a spatial scale of only a few millimetres. With the recent development of very small size microchip-based sensors, it is now practicable to measure the humidity at different locations within these microenvironments. In the laboratory study described here, sensors were used to measure the conditions in a number of typical flooring systems using a variety of coverings. The measurements were compared with the predictions of a well-established and validated dynamic heat and moisture transfer simulation model. In order to provide an accurate input to the model, permeability and sorption tests were carried out on the flooring materials used. Finally, using monitored domestic environmental data, simulation results were coupled to a simplified growth model to predict dust mite activity in the flooring systems under realistic boundary conditions