Properties of the mechanosensitive channel MscS pore revealed by tryptophan scanning mutagenesis

Funding This work was supported by a Wellcome Trust Programme grant [092552/A/10/Z awarded to I.R.B., S.M., J. H. Naismith (University of St Andrews, St Andrews, U.K.), and S. J. Conway (University of Oxford, Oxford, U.K.)] (T.R. and M.D.E.), by a BBSRC grant (A.R.) [BB/H017917/1 awarded to I.R.B., J. H. Naismith, and O. Schiemann (University of St Andrews)], by a Leverhulme Emeritus Fellowship (EM-2012-060\2), and by a CEMI grant to I.R.B. from the California Institute of Technology. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013 FP7/2007-2011) under Grant PITN-GA-2011-289384 (FP7-PEOPLE-2011-ITN NICHE) (H.G.) (awarded to S.M.).Peer reviewedPublisher PD

Integrated stress response of Escherichia coli to methylglyoxal : transcriptional readthrough from the nemRA operon enhances protection through increased expression of glyoxalase I

© 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.Peer reviewedPublisher PD

Collective response of self-organized clusters of mechanosensitive channels

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The kinetics of fluoride uptake by synthetic hydroxyapatite

The kinetics of fluoride uptake by synthetic hydroxyapatite from aqueous solution has been studied. Experiments involved exposing 0.1 g of synthetic hydroxyapatite to 5 cm3 of sodium fluoride solution in the concentration range 100-1000 ppm fluoride and determining fluoride concentration at regular time intervals with a fluoride ion-selective electrode. In all cases, uptake was found to follow pseudo-second order kinetics with correlation coefficients of at least 0.998; all systems equilibrated by 24 hours with equilibrium uptake values that varied with the initial fluoride concentration. The kinetic results differ from those previously reported for much lower concentrations of fluoride, but in the present case, the concentrations were of clinical relevance, as they are those used in fluoride-containing dental products. Further work is necessary to determine how well these findings model uptake by natural hydroxyapatite and hence the extent to which they might apply in vivo

Openness Personality Trait Associated With Benefit From a Nonpharmacological Breathlessness Intervention in People With Intrathoracic Cancer: An Exploratory Analysis

Context: Breathlessness is common in people with lung cancer. Nonpharmacological breathlessness interventions reduce distress because of and increase mastery over breathlessness. Objectives: Identify patient characteristics associated with response to breathlessness interventions. Methods: Exploratory secondary trial data analysis. Response defined as a one-point improvement in 0–10 Numerical Rating Scale of worst breathlessness/last 24 hours (response—worst) or a 0.5-point improvement in the Chronic Respiratory Questionnaire (CRQ) mastery (response—mastery) at four weeks. Univariable regression explored relationships with plausible demographic, clinical, and psychological variables followed by multivariable regression for associated (P < 0.05) variables. Results: About 158 participants with intrathoracic cancer (mean age 69.4 [SD 9.35] years; 40% women) were randomized to one or three breathlessness training sessions. About 91 participants had evaluable data for response—worst and 107 for response—mastery. In the univariable analyses, the personality trait openness was associated with response—worst (odds ratio [OR] 1.99 [95% CI 1.08–3.67]; P = 0.028) and response—mastery (OR 1.84 [95% CI 1.04–3.23]; P = 0.035). Higher CRQ—fatigue (OR 0.61 [95% CI 0.41–0.91]; P = 0.015), CRQ—emotion (OR 0.68 [95% CI 0.47–0.96]; P = 0.030), and worse CRQ—mastery (OR 0.61 [95% CI 0.42–0.88]; P = 0.008), and the presence of metastases and fatigue were associated with reduced odds of response—mastery. In the adjusted response—mastery model, only openness remained (OR 1.73 [95% CI 0.95–3.15]; P = 0.072). Conclusion: Worse baseline health, worse breathlessness mastery, but not severity, and openness were associated with a better odds of response. Breathlessness services must be easy to access, and patients should be encouraged and supported to attend

Interaction of fluoride complexes derived from glass-ionomer cements with hydroxyapatite

A study has been undertaken of the interaction of complexed fluoride extracted from glass-ionomer dental cements with synthetic hydroxyapatite powder. Extracts were prepared from two commercial glass-ionomers (Fuji IX and ChemFlex) under both neutral and acidic conditions. They were analysed by ICP-OES and by fluoride-ion selective electrode with and without added TISAB to decomplex the fluoride. The pH of the acid extracts was 4, conditions under which fluoridecomplexes with protons as HF or HF2, it also complexes with aluminium, which was found to be present in higher amounts in the acid extracts. Fluoride was found to be almost completely complexed in acid extracts, but not in neutral extracts, which contained free fluoride ions. Exposure of these extracts to synthetic hydroxyapatite powder showed that fluoride was taken up rapidly (within 5 minutes), whether or not it was complexed. SEM (EDAX) study of recovered hydroxyapatite showed only minute traces of aluminium taken up under all conditions. This showed that aluminium interacts hardly at all with hydroxyapatite, and hence is probably not involved in the remineralisation process