Structural studies of glucose-6-phosphate and NADP+ binding to human glucose-6-phosphate dehydrogenase

Human glucose-6-phosphate dehydrogenase (G6PD) is NADP(+)-dependent and catalyses the first and rate-limiting step of the pentose phosphate shunt. Binary complexes of the human deletion mutant, DeltaG6PD, with glucose-6-phosphate and NADP(+) have been crystallized and their structures solved to 2.9 and 2.5 A, respectively. The structures are compared with the previously determined structure of the Canton variant of human G6PD (G6PD(Canton)) in which NADP(+) is bound at the structural site. Substrate binding in DeltaG6PD is shown to be very similar to that described previously in Leuconostoc mesenteroides G6PD. NADP(+) binding at the coenzyme site is seen to be comparable to NADP(+) binding in L. mesenteroides G6PD, although some differences arise as a result of sequence changes. The tetramer interface varies slightly among the human G6PD complexes, suggesting flexibility in the predominantly hydrophilic dimer-dimer interactions. In both complexes, Pro172 of the conserved peptide EKPxG is in the cis conformation; it is seen to be crucial for close approach of the substrate and coenzyme during the enzymatic reaction. Structural NADP(+) binds in a very similar way in the DeltaG6PD-NADP(+) complex and in G6PD(Canton), while in the substrate complex the structural NADP(+) has low occupancy and the C-terminal tail at the structural NADP(+) site is disordered. The implications of possible interaction between the structural NADP(+) and G6P are considered.published_or_final_versio

Trends in HbA1c thresholds for initiation of hypoglycemic agents:Impact of changed recommendations for older and frail patients

Aims: Less strict glycated hemoglobin (HbA1c) thresholds have been recommended in older and/or frail type 2 diabetes (T2D) patients than in younger and less frail patients for initiating hypoglycemic agents since 2011. We aimed to assess trends in HbA1c thresholds at initiation of a first hypoglycemic agent(s) in T2D patients and the influence of age and frailty on these trends. Materials and methods: The groningen initiative to analyze type 2 diabetes treatment (GIANTT) database was used, which includes primary care T2D patients from the north of the Netherlands. Patients initiating a first non-insulin hypoglycemic agent(s) between 2008 and 2014 with an HbA1c measurement within 120 days before initiation were included. The influence of calendar year, age, or frailty and the interaction between calendar year and age or frailty were assessed using multilevel regression analyses adjusted for confounders. Results: We included 4588 patients. The mean HbA1c threshold at treatment initiation was 7.4% up to 2010, decreasing to 7.1% in 2011 and increasing to 7.4% in 2014. This quadratic change over the years was significant (P 0.05). Conclusions: HbA1c thresholds at initiation of a first hypoglycemic agent(s) changed significantly over time, showing a decrease after 2010 and an increase after 2012. The HbA1c threshold at initiation was not influenced by age or frailty, which is in contrast with recommendations for more personalized treatment

PHS63 Cost-Effectiveness Analysis Of A Pharmacist-Led Intervention On Improving Inhaler Adherence In Patients With Chronic Obstructive Pulmonary Disease

Objectives: The Belgian community pharmacist-led PHARMACOP intervention provided educational inhalation training sessions and motivational interviewing regarding medication use in patients with Chronic Obstructive Pulmonary Disease (COPD). The program significantly improved medication adherence and inhalation techniques compared with usual care. This study aimed to evaluate its costeffectiveness. Methods: An economic analysis was performed from the Belgian health care payer's perspective. A Markov model was constructed in which a cohort of 1,000 patients with COPD receiving the 3-month PHARMACOP-intervention or usual care, was followed. This cohort had a mean age of 70 years, 66% were male, 43% current smokers and patients had a mean Forced Expiratory Volume in 1 second of % predicted of 50. Three types of costs were calculated: intervention costs, medication costs and exacerbation costs. Outcome measures included the number of hospital-treated exacerbations, cost per prevented hospital-treated exacerbation and cost per Quality Adjusted Life-Year (QALY) gained. Follow-up was 1 year in the basecase analysis. Univariate-, probabilistic sensitivity- and scenario analyses (including long-term follow-up) were performed to assess uncertainty. Results: In the basecase analysis, the average overall costs per patient for the PHARMACOPintervention and usual care were € 2,221 and € 2,448, respectively within the 1-year time horizon. This reflects cost savings of € 227 for the PHARMACOP-intervention. The PHARMACOP-intervention resulted in the prevention of 71 hospital-treated exacerbations (167 for PHARMACOP versus 238 for usual care), i.e. 0.07 (95%CI: 0.04-0.10) incremental hospital-treated exacerbations per patient. In addition, a small (<0.001 QALYs) increase in QALYs was observed. Results showed robust costsavings in various sensitivity analyses. Conclusions: Optimization of current pharmacotherapy (e.g. close monitoring of inhalation technique and medication adherence) has been shown to be cost-saving and should be considered before adding new therapies

Solution of the structure of tetrameric human glucose 6-phosphate dehydrogenase by molecular replacement

Recombinant human glucose 6-phosphate dehydrogenase (G6PD) has been crystallized and its structure solved by molecular replacement. Crystals of the natural mutant R459L grow under similar conditions in space groups P212121 and C2221 with eight or four 515-residue molecules in the asymmetric unit, respectively. A non-crystallographic 222 tetramer was found in the C2221 crystal form using a 4 A resolution data set and a dimer of the large beta + alpha domains of the Leuconostoc mesenteroides enzyme as a search model. This tetramer was the only successful search model for the P212121 crystal form using data to 3 A. Crystals of the deletion mutant DeltaG6PD grow in space group F222 with a monomer in the asymmetric unit; 2.5 A resolution data have been collected. Comparison of the packing of tetramers in the three space groups suggests that the N-terminal tail of the enzyme prevents crystallization with exact 222 molecular symmetry.published_or_final_versio

High incidence of diabetes after stroke in young adults and risk of recurrent vascular events: the FUTURE study

BACKGROUND: Diabetes diagnosed prior to stroke in young adults is strongly associated with recurrent vascular events. The relevance of impaired fasting glucose (IFG) and incidence of diabetes after young stroke is unknown. We investigated the long-term incidence of diabetes after young stroke and evaluated the association of diabetes and impaired fasting glucose with recurrent vascular events. METHODS: This study was part of the FUTURE study. All consecutive patients between January 1, 1980, and November 1, 2010 with TIA or ischemic stroke, aged 18-50, were recruited. A follow-up assessment was performed in survivors between November 1, 2009 and January 1, 2012 and included an evaluation for diabetes, fasting venous plasma glucose and recurrent vascular events. The association of diabetes and IFG with recurrent vascular events was assessed by logistic regression analysis, adjusted for age, sex and follow-up duration. RESULTS: 427 survivors without a medical history of diabetes were included in the present analysis (mean follow-up of 10.1 (SD 8.4) years; age 40.3 (SD 7.9) years). The incidence rate of diabetes was 7.9 per 1000 person-years and the prevalence of IFG was 21.1%. Patients with diabetes and IFG were more likely to have experienced any vascular event than those with normal fasting glucose values (OR 3.5 (95%CI 1.5-8.4) for diabetes and OR 2.5 (95%CI 1.3-4.8) for IFG). CONCLUSIONS: Diabetes or IFG in young stroke survivors is frequent and is associated with recurrent vascular events. Regular screening for IFG and diabetes in this population, yields potential for secondary prevention

Patient-reported outcomes after 10-year follow-up of intensive, multifactorial treatment in individuals with screen-detected type 2 diabetes: the ADDITION-Europe trial.

AIMS: To present the longer-term impact of multifactorial treatment of type 2 diabetes on self-reported health status, diabetes-specific quality of life, and diabetes treatment satisfaction at 10-year follow up of the ADDITION-Europe trial. METHODS: The ADDITION-Europe trial enrolled 3057 individuals with screen-detected type 2 diabetes from four centres [Denmark, the UK (Cambridge and Leicester) and the Netherlands], between 2001 and 2006. Participants were randomized at general practice level to intensive treatment or to routine care . The trial ended in 2009 and a 10-year follow-up was performed at the end of 2014. We measured self-reported health status (36-item Short-Form Health Survey and EQ-5D), diabetes-specific quality of life (Audit of Diabetes-Dependent Quality of Life questionnaire), and diabetes treatment satisfaction (Diabetes Treatment Satisfaction Questionnaire) at different time points during the study period. A mixed-effects model was applied to estimate the effect of intensive treatment (intention-to-treat analyses) on patient-reported outcome measures for each centre. Centre-specific estimates were pooled using a fixed effects meta-analysis. RESULTS: There was no difference in patient-reported outcome measures between the routine care and intensive treatment arms in this 10-year follow-up study [EQ-5D: -0.01 (95% CI -0.03, 0.01); Physical Composite Score (36-item Short-Form Health Survey): -0.27 (95% CI -1.11, 0.57), Audit of Diabetes-Dependent Quality of Life questionnaire: -0.01 (95% CI -0.11, 0.10); and Diabetes Treatment Satisfaction Questionnaire: -0.20 (95% CI -0.70, 0.29)]. CONCLUSIONS: Intensive, multifactorial treatment of individuals with screen-detected type 2 diabetes did not affect self-reported health status, diabetes-specific quality of life, or diabetes treatment satisfaction at 10-year follow-up compared to routine care

Kidney Dysfunction Increases Mortality and Incident Events after Young Stroke: The FUTURE Study.

BACKGROUND: In about 30% of young stroke patients, no cause can be identified. In elderly patients, kidney dysfunction has been suggested as a contributing risk factor for mortality as well as stroke. There are hypotheses that novel non-traditional risk factors, like chronic inflammation and oxidative stress, are involved in chronic kidney disease, affecting the cerebral microvasculature that would in turn lead to stroke. Our objective is to investigate the influence of kidney dysfunction on long-term mortality and incident vascular events after stroke in young adults aged 18 through 50 and if this relationship would be independent of other cardiovascular risk factors. METHODS: We prospectively included 460 young stroke patients with an ischemic stroke or transient ischemic attack admitted to our department between January 1, 1980 and November 1, 2010. Follow-up was done between 2014 and 2015. Estimated glomerular filtration rate (eGFR) was calculated from baseline creatinine levels and was divided in 3 subgroups: eGFR 120 ml/min/1.73 m2. Cox proportional hazard models were used to determine the effect of kidney dysfunction on mortality and incident vascular events, adjusting for cardiovascular risk factors. RESULTS: An eGFR <60 (HR 4.6; 95% CI 2.6-8.2) was associated with an increased risk of death and an increased risk of incident stroke (HR 4.1; 95% CI 1.9-9.0) independent of cardiovascular risk factors, but it was not associated with other vascular events. The point estimate for the 15-year cumulative mortality was 70% (95% CI 46-94) for patients with a low eGFR, 24% (95% CI 18-30) for patients with a normal eGFR and 30% (95% CI 12-48) for patients with a high eGFR. The point estimate for the 15-year cumulative risk of incident stroke was 45% (95% CI 16-74) for patients with a low eGFR, 13% (95% CI 9-17) for patients with a normal eGFR and 8% (95% CI 0-18) for patients with a high eGFR. CONCLUSIONS: Kidney dysfunction is related to long-term mortality and stroke recurrence, but not to incident cardiovascular disease, on average 11 years after young stroke. This warrants a more intensive follow-up of young stroke patients with signs of kidney dysfunction in the early phase. In addition, the clear association between kidney dysfunction and incident stroke seen in our young stroke population might be a first step in the recognition of kidney dysfunction as a new risk factor for the development of stroke at young age. Also, it can lead to new insights in the etiological differences between cardiovascular and cerebrovascular disease.This study was funded by the Dutch Epilepsy Fund (grant number 10-18)

An appropriate tool for entrepreneurial learning in SMEs? The case of the 20Twenty Leadership Programme

The 20Twenty Leadership Programme was developed by Cardiff Metropolitan University as an executive education programme to be delivered within South Wales to small businesses. It is funded by the European Social Fund (ESF) and administered by the Welsh European Funding Office and has the key aim of developing SME’s growth potential via a range of leadership and management skills, including a focus on ‘soft’ skills. The focus of this paper is to place the 20Twenty Leadership Programme within the wider context of entrepreneurship policy and SME training initiatives in particular, and then to examine the rationale and delivery methods of the Programme in relation to these. It also reflects on the Programme’s success (or otherwise) to date where possible. Finally, the paper seeks to suggest fruitful areas of further research both in terms of the 20Twenty Leadership Programme itself, but also with regard to evaluation in relation to other parallel programmes, and to SME training initiatives more generally

Image-guided versus blind corticosteroid injections in adults with shoulder pain: A systematic review

<p>Abstract</p> <p>Background</p> <p>Corticosteroid injections can be performed blind (landmark-guided) or with image guidance, and this may account for variable clinical outcomes. The objective of this study was to assess the effectiveness and safety of image-guided versus blind corticosteroid injections in improving pain and function among adults with shoulder pain.</p> <p>Methods</p> <p>MEDLINE, the Cochrane Controlled Trials Register and EMBASE were searched to May 2010. Additional studies were identified by searching bibliographies of shortlisted articles. Search items included blind, landmark, anatomical, clinical exam, image-guided, ultrasound, fluoroscopy, steroid injection, frozen shoulder, random allocation, randomized controlled trial (RCT) and clinical trial.</p> <p>Randomized controlled studies comparing image-guided versus blind (landmark-guided) corticosteroid shoulder injections that examined pain, function and/or adverse events were included. Independent extraction was done by two authors using a form with pre-specified data fields, including risk of bias appraisal. Conflicts were resolved by discussion. The decision to pool data was based on assessment of clinical design homogeneity. When warranted, studies were pooled under a random-effects model.</p> <p>Results</p> <p>Two RCTs for pain, function and adverse events (n = 101) met eligibility criteria. No serious threats to validity were found. Both trials compared ultrasound-guided versus landmark-guided injections and were judged similar in clinical design. Low to moderate heterogeneity was observed: shoulder pain I²= 60%, function I²= 22%. A meta-analysis demonstrated greater improvement with ultrasound-guided injections at 6 weeks after injection in both pain (mean difference = 2.23 [95% CI: 1.27, 3.18]), as assessed with a 0 to 10 visual analogue scale, and shoulder function (standardised mean difference = 1.09 [95% CI: 0.61, 1.57]) as assessed with shoulder function scores. Although more adverse events (all mild) were reported with landmark-guided injections, the difference was not statistically significant (risk ratio = 0.20 [95% CI: 0.04, 1.13]).</p> <p>This review was only based on two moderate-sized trials. Blinding of patients was not performed in both trials, causing some risk of bias in outcome assessment since primary endpoints were wholly or partially patient-reported.</p> <p>Conclusion</p> <p>There is a paucity of RCTs on image-guided versus landmark-guided corticosteroid shoulder injections examining pain, function and adverse events. In this review, patients who underwent image-guided (ultrasound) injections had statistically significant greater improvement in shoulder pain and function at 6 weeks after injection. Image-guided (ultrasound) corticosteroid injections potentially offer a significantly greater clinical improvement over blind (landmark-guided) injections in adults with shoulder pain. However, this apparent benefit requires confirmation from further studies (adequately-powered and well-executed RCTs).</p

Magnetic Coupling in the Quiet Solar Atmosphere

Three kinds of magnetic couplings in the quiet solar atmosphere are highlighted and discussed, all fundamentally connected to the Lorentz force. First the coupling of the convecting and overshooting fluid in the surface layers of the Sun with the magnetic field. Here, the plasma motion provides the dominant force, which shapes the magnetic field and drives the surface dynamo. Progress in the understanding of the horizontal magnetic field is summarized and discussed. Second, the coupling between acoustic waves and the magnetic field, in particular the phenomenon of wave conversion and wave refraction. It is described how measurements of wave travel times in the atmosphere can provide information about the topography of the wave conversion zone, i.e., the surface of equal Alfv\'en and sound speed. In quiet regions, this surface separates a highly dynamic magnetic field with fast moving magnetosonic waves and shocks around and above it from the more slowly evolving field of high-beta plasma below it. Third, the magnetic field also couples to the radiation field, which leads to radiative flux channeling and increased anisotropy in the radiation field. It is shown how faculae can be understood in terms of this effect. The article starts with an introduction to the magnetic field of the quiet Sun in the light of new results from the Hinode space observatory and with a brief survey of measurements of the turbulent magnetic field with the help of the Hanle effect.Comment: To appear in "Magnetic Coupling between the Interior and the Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200