39 research outputs found

    Phenylpyrrole fungicides act on triosephosphate isomerase to induce methylglyoxal stress and alter hybrid histidine kinase activity.

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    Fludioxonil, a natural product of pyrrolnitrin, is a potent fungicide used on crops worldwide. Drug action requires the presence of a group III hybrid histidine kinase (HHK) and the high osmolarity glycerol (HOG) pathway. We have reported that the drug does not act directly on HHK, but triggers the conversion of the kinase to a phosphatase, which dephosphorylates Ypd1 to constitutively activate HOG signaling. Still, the direct drug target remains unknown and mode of action ill defined. Here, we heterologously expressed a group III HHK, dimorphism-regulating kinase 1 (Drk1) in Saccharomyces cerevisae to delineate fludioxonil's target and action. We show that the drug interferes with triosephosphate isomerase (TPI) causing release of methylglyoxal (MG). MG activates the group III HHK and thus the HOG pathway. Drug action involved Drk1 cysteine 392, as a C392S substitution increased drug resistance in vivo. Drug sensitivity was reversed by dimedone treatment, indicating Drk1 responds in vivo to an aldehydic stress. Fludioxonil treatment triggered elevated cytosolic methylglyoxal. Likewise, methylglyoxal treatment of Drk1-expressing yeast phenocopied treatment with fludioxonil. Fludioxonil directly inhibited TPI and also caused it to release methylglyoxal in vitro. Thus, TPI is a drug target of the phenylpyrrole class of fungicides, inducing elevated MG which alters HHK activity, likely converting the kinase to a phosphatase that acts on Ypd1 to trigger HOG pathway activation and fungal cell death

    The PrEscription of intraDialytic exercise to improve quAlity of Life in patients with chronic kidney disease trial:study design and baseline data for a multicentre randomized controlled trial

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    Background: Exercise interventions designed to improve physical function and reduce sedentary behaviour in haemodialysis (HD) patients might improve exercise capacity, reduce fatigue and lead to improved quality of life (QOL). The PEDAL study aimed to evaluate the effectiveness of a 6-month intradialytic exercise programme on quality of life (QOL) and physical function, compared to usual care for patients on HD in the UK.Methods: We conducted a prospective, pragmatic multicentre randomised controlled trial (RCT) in 335 HD patients and randomly (1:1) assigned them to either, i) intradialytic exercise training plus usual care maintenance HD, or ii) usual care maintenance HD. The primary outcome of the study was the change in Kidney Disease Quality of Life (KDQOL-SF 1.3) Physical Component Score between baseline and 6 months. Additional secondary outcomes included changes in: peak aerobic capacity, physical fitness, habitual physical activity levels and falls (International Physical Activity Questionnaire, Duke’s Activity Status Index and Tinetti Falls Efficacy Scale), quality of life and symptom burden assessments (EQ5D), arterial stiffness (pulse wave velocity), anthropometric measures, resting blood pressure, clinical chemistry, safety and harms associated with the intervention, hospitalisations, and cost-effectiveness. A nested qualitative study investigated the experience and acceptability of the intervention for both participants and members of the renal healthcare team.Results: At baseline assessment, 62.4% of the randomised cohort were male, the median age was 59.3 years, and 50.4% were White. Prior cerebrovascular events and myocardial infarction (MI) were present in 8 and 12% of the cohort, respectively, 77.9% of patients had 3hypertension and 39.4% had diabetes. Baseline clinical characteristic and laboratory data for the randomised cohort were generally concordant with data from the UK Renal Registry.Conclusion: The results from this study will address a significant knowledge gap in the prescription of exercise interventions for patients receiving maintenance HD therapy and inform the development of intradialytic exercise programmes both nationally and internationally.Trial Registration: ISRCTN N83508514; registered on 17th December 2014.</p

    Randomized Trial-PrEscription of intraDialytic exercise to improve quAlity of Life in Patients Receiving Hemodialysis

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    Introduction: Whether clinically implementable exercise interventions in people receiving hemodialysis (HD) therapy improve health-related quality of life (HRQoL) remains unknown. The PrEscription of intraDialytic exercise to improve quAlity of Life PEDAL) study evaluated the clinical benefit and cost-effectiveness of a 6-month intradialytic exercise program. Methods: In a multicenter, single-blinded, randomized, controlled trial, people receiving HD were randomly assigned to (i) intradialytic exercise training (exercise intervention group [EX]) and (ii) usual care (control group [CON]). Primary outcome was change in Kidney Disease Quality of Life Short-Form Physical Component Summary (KDQOL-SF 1.3 PCS) from baseline to 6 months. Cost-effectiveness was determined using health economic analysis; physiological impairment was evaluated by peak oxygen uptake; and harms were recorded. Results: We randomized 379 participants; 335 and 243 patients (EX  = 127; CON  = 116) completed baseline and 6-month assessments, respectively. Mean difference in change PCS from baseline to 6 months between EX and CON was 2.4 (95% confidence interval [CI]: -0.1 to 4.8) arbitrary units ( = 0.055); no improvements were observed in peak oxygen uptake or secondary outcome measures. Participants in the intervention group had poor compliance (47%) and poor adherence (18%) to the exercise prescription. Cost of delivering intervention ranged from US598toUS598 to US1092 per participant per year. The number of participants with harms was similar between EX ( = 69) and CON ( = 56). A primary limitation was the lack of an attention CON. Many patients also withdrew from the study or were too unwell to complete all physiological outcome assessments. Conclusions: A 6-month intradialytic aerobic exercise program was not clinically beneficial in improving HRQoL as delivered to this cohort of deconditioned patients on HD

    The 2018 GaN power electronics roadmap

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    Gallium nitride (GaN) is a compound semiconductor that has tremendous potential to facilitate economic growth in a semiconductor industry that is silicon-based and currently faced with diminishing returns of performance versus cost of investment. At a material level, its high electric field strength and electron mobility have already shown tremendous potential for high frequency communications and photonic applications. Advances in growth on commercially viable large area substrates are now at the point where power conversion applications of GaN are at the cusp of commercialisation. The future for building on the work described here in ways driven by specific challenges emerging from entirely new markets and applications is very exciting. This collection of GaN technology developments is therefore not itself a road map but a valuable collection of global state-of-the-art GaN research that will inform the next phase of the technology as market driven requirements evolve. First generation production devices are igniting large new markets and applications that can only be achieved using the advantages of higher speed, low specific resistivity and low saturation switching transistors. Major investments are being made by industrial companies in a wide variety of markets exploring the use of the technology in new circuit topologies, packaging solutions and system architectures that are required to achieve and optimise the system advantages offered by GaN transistors. It is this momentum that will drive priorities for the next stages of device research gathered here
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