Metabolic and functional consequences of cytosolic 5′-nucleotidase-IA overexpression in neonatal rat cardiomyocytes

Adenosine exerts a spectrum of energy-preserving actions on the heart negative chronotropic effects. The pathways leading to adenosine formation have remained controversial. In particular, although cytosolic 5′-nucleotidases can catalyze adenosine formation in cardiomyocytes, their contribution to the actions of adenosine has not been documented previously. We recently cloned two closely related AMP-preferring cytosolic 5′-nucleotidases (cN-IA and -IB); the A form predominates in the heart. In this study, we overexpressed pigeon cN-IA in neonatal rat cardiomyocytes using an adenovirus. cN-IA overexpression increased adenosine formation and release into the medium caused by simulated hypoxia and by isoproterenol in the absence and presence of inhibitors of adenosine metabolism. Adenosine release was not affected by an ecto-5′-nucleotidase inhibitor, α,β-methylene-ADP, but was affected by a nucleoside transporter, dipyridamole. The positive chronotropic effect of isoproterenol (130 ±3 vs. 100 ±4 beats/min) was inhibited (107 ±3 vs. 94 ±3 beats/min) in cells overexpressing cN-IA, and this was reversed by the addition of the adenosine receptor antagonist 8-(p-sulfophenyl)theophilline (120 ± 3 vs. 90 ± 4 beats/min). Our results demonstrate that overexpressed cN-IA can be sufficiently active in cardiomyocytes to generate physiologically effective concentrations of adenosine at its receptors.Fil: Sala-Newby, Graciela B.. University of Bristol; Reino UnidoFil: Freeman, Nicola V. E.. University of Bristol; Reino UnidoFil: Curto, Maria de Los Angeles. University of Bristol; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Newby, Andrew C.. University of Bristol; Reino Unid

Fibre intake among the Belgian population by sex-age and sex-education groups and its association with BMI and waist circumference

The objectives of the present study were to assess total dietary fibre intake and the main contributors to fibre intake in the Belgian population by sex-age and sex-education groups and to investigate its relationship with BMI and waist circumference (WC). The participants of the Belgian food consumption survey (2004) were randomly selected. Information about food intake was collected using two repeated, non-consecutive 24 h recall interviews. A total of 3083 individuals (>= 15 years; 1546 men and 1537 women) completed both interviews. The main contributors to total fibre intake (17.8 g/d) were cereals and cereal products (34%; 5.9 g/d), potatoes and other tubers (18.6%; 3.3 g/d), fruits (14.7%; 2.8 g/d) and vegetables (14.4%; 2.6 g/d). Legume fibre intake was extremely low (0.672%; 0.139 g/d). In all sex-age and sex-education groups, total fibre intake was below the recommendations of the Belgian Superior Health Council. Men (21 g/d) consumed significantly more fibre than women (17.3 g/d) (P < 0.001). Lower educated men and higher educated women reported the highest fibre intake. A significant inverse association was found between total fibre intake and WC (beta = -0.118, P < 0.001). Fruit-derived fibre was positively associated with WC (beta = 0.731, P=0.001). In summary, total fibre intake was inversely associated with WC, whereas fruit-derived fibre intake was positively associated with WC in the Belgian population

Work hard, party harder:drug use and sexual behaviour in young British casual workers in Ibiza, Spain

Background: Every summer, young people flock to nightlife-focused holiday resorts around the world to find casual work. Despite being exposed to hedonistic environments, often for several months, little is known about their substance use, sexual activity and health service needs over this extended amount of time abroad. Methods: A short anonymous questionnaire examining alcohol and drug use, sexual behaviour and use of health services was administered to young British casual workers aged 16–35 in San Antonio, Ibiza (n = 171). Results: 97.7% of casual workers used alcohol in Ibiza, and the majority (85.3%) used drugs. Almost half (43.5%) of all participants used a drug in Ibiza that they had never used in the UK. Most casual workers arrived in Ibiza without a partner or spouse (86.5%). Of these, 86.9% had sex during their stay and 50.0% had unprotected sex; often while under the influence of alcohol. Only 14.3% of those having unprotected sex with a new partner sought a sexual health check-up in Ibiza, although 84.1% intended to do this on their return to the UK. Conclusion: Substance use and sexual risk taking is widespread among young British casual workers in Ibiza. Such international nightlife resorts represent key settings for substance-related health and social problems, and for the international spread of sexually transmitted infections. Addressing the health needs of casual workers and the environments that permit and promote their excessive behaviour requires collaboration between authorities in home and destination countries and the tourism industry

Structure-Free Validation of Residual Dipolar Coupling and Paramagnetic Relaxation Enhancement Measurements of Disordered Proteins.

Residual dipolar couplings (RDCs) and paramagnetic relaxation enhancements (PREs) have emerged as valuable parameters for defining the structures and dynamics of disordered proteins by nuclear magnetic resonance (NMR) spectroscopy. Procedures for their measurement, however, may lead to conformational perturbations because of the presence of the alignment media necessary for recording RDCs, or of the paramagnetic groups that must be introduced for measuring PREs. We discuss here experimental methods for quantifying these effects by considering the case of the 40-residue isoform of the amyloid β peptide (Aβ40), which is associated with Alzheimer's disease. By conducting RDC measurements over a range of concentrations of certain alignment media, we show that perturbations arising from transient binding of Aβ40 can be characterized, allowing appropriate corrections to be made. In addition, by using NMR experiments sensitive to long-range interactions, we show that it is possible to identify relatively nonperturbing sites for attaching nitroxide radicals for PRE measurements. Thus, minimizing the conformational perturbations introduced by RDC and PRE measurements should facilitate their use for the rigorous determination of the conformational properties of disordered proteins.This is the author accepted manuscript. The final version is available from ACS via http://dx.doi.org/10.1021/acs.biochem.5b0067

Applications of residual stress in combatting fatigue and fracture

Residual stresses have a significant impact on the propensity for engineering components and structures to undergo fatigue and fracture, with either a positive (life enhancing) or negative (life reducing) effect that is largely dependent on the sign of the residual stress relative to that of the applied stress, i.e. on whether they add to, or subtract from, the applied stresses. Accurate life prediction relies on accurate experimental assessment of residual stresses, often combined with simulation using advanced numerical analysis techniques, that must be calibrated against real service data and this implies a necessity for ongoing condition monitoring. The present paper will outline some industrial applications where detailed knowledge of residual stress is advantageous in assessing their influence on fatigue and fracture erformance, and hence assists in combatting failure. It will also draw attention to some examples of failures of expensive structures where residual stresses played a role and consider the design and/or fabrication measures that would have led to an amelioration of the level of residual stress and hence prolonged life

Aberrant Polycystin-1 Expression Results in Modification of Activator Protein-1 Activity, whereas Wnt Signaling Remains Unaffected

Polycystin-1, the polycystic kidney disease 1 gene product, has been implicated in several signaling complexes that are known to regulate essential cellular functions. We investigated the role of polycystin-1 in Wnt signaling and activator protein-1 (AP-1) activation. To this aim, a membrane-targeted construct encoding the conserved C-terminal region of mouse polycystin- 1 reported to mediate signal transduction activity was expressed in human embryonic and renal epithelial cells. To ensure specificity and minimal cotransfection effects, we focused our study on the endogenous proteins that actually transduce the signals, -catenin and T-cell factor/lymphoid-enhancing factor for Wnt signaling and (phosphorylated) c-Jun, ATF2, and c-Fos for AP-1. Our data indicate that the C-terminal region of polycystin-1 activates AP-1 by inducing phosphorylation and expression of at least c-Jun and ATF2, whereas c-Fos was not affected. Under our experimental conditions, polycystin-1 did not modulate Wnt signaling. AP-1 activity was aberrant in human autosomal dominant polycystic kidney disease (ADPKD) renal cystic epithelial cells and in renal epithelial cells expressing transgenic full-length polycystin- 1, resulting in decreased Jun-ATF and increased Jun-Fos activity, whereas Wnt signaling remained unaffected. Since our data indicate that aberrant polycystin- 1 expression results in altered AP-1 activity, polycystin-1 may be required for adequate AP-1 activity

The Significance of the Location of Mutations for the Native-State Dynamics of Human Lysozyme

peer reviewe

Improved identification of abdominal aortic aneurysm using the Kernelized Expectation Maximization algorithm

Abdominal aortic aneurysm (AAA) monitoring and risk of rupture is currently assumed to be correlated with the aneurysm diameter. Aneurysm growth, however, has been demonstrated to be unpredictable. Using PET to measure uptake of [18F]-NaF in calcified lesions of the abdominal aorta has been shown to be useful for identifying AAA and to predict its growth. The PET low spatial resolution, however, can affect the accuracy of the diagnosis. Advanced edge-preserving reconstruction algorithms can overcome this issue. The kernel method has been demonstrated to provide noise suppression while retaining emission and edge information. Nevertheless, these findings were obtained using simulations, phantoms and a limited amount of patient data. In this study, the authors aim to investigate the usefulness of the anatomically guided kernelized expectation maximization (KEM) and the hybrid KEM (HKEM) methods and to judge the statistical significance of the related improvements. Sixty-one datasets of patients with AAA and 11 from control patients were reconstructed with ordered subsets expectation maximization (OSEM), HKEM and KEM and the analysis was carried out using the target-to-blood-pool ratio, and a series of statistical tests. The results show that all algorithms have similar diagnostic power, but HKEM and KEM can significantly recover uptake of lesions and improve the accuracy of the diagnosis by up to 22% compared to OSEM. The same improvements are likely to be obtained in clinical applications based on the quantification of small lesions, like for example cancer

Positron Emission Tomography and Magnetic Resonance Imaging of Cellular Inflammation in Patients with Abdominal Aortic Aneurysms.

OBJECTIVES: Inflammation is critical in the pathogenesis of abdominal aortic aneurysm (AAA) disease. Combined (18)F-fludeoxyglucose ((18)F-FDG) positron emission tomography with computed tomography (PET-CT) and ultrasmall superparamagnetic particles of iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) are non-invasive methods of assessing tissue inflammation. The aim of this study was to compare these techniques in patients with AAA. MATERIALS AND METHODS: Fifteen patients with asymptomatic AAA with diameter 46 ± 7 mm underwent PET-CT with (18)F-FDG, and T2*-weighted MRI before and 24 hours after administration of USPIO. The PET-CT and MRI data were then co-registered. Standardised uptake values (SUVs) were calculated to measure (18)F-FDG activity, and USPIO uptake was determined using the change in R2*. Comparisons between the techniques were made using a quadrant analysis and a voxel-by-voxel evaluation. RESULTS: When all areas of the aneurysm were evaluated, there was a modest correlation between the SUV on PET-CT and the change in R2* on USPIO-enhanced MRI (n = 70,345 voxels; r = .30; p < .0001). Although regions of increased (18)F-FDG and USPIO uptake co-localised on occasion, this was infrequent (kappa statistic 0.074; 95% CI 0.026-0.122). (18)F-FDG activity was commonly focused in the shoulder region whereas USPIO uptake was more apparent in the main body of the aneurysm. Maximum SUV was lower in patients with mural USPIO uptake. CONCLUSIONS: Both (18)F-FDG PET-CT and USPIO-MRI uptake identify vascular inflammation associated with AAA. Although they demonstrate a modest correlation, there are distinct differences in the pattern and distribution of uptake, suggesting a differential detection of macrophage glycolytic and phagocytic activity respectively.This research was supported by grants from the National Institutes of Health Research (NIHR) Efficacy and Mechanism Evaluation Programme (11/20/03), the British Heart Foundation (PG/09/083) and the Evelyn Trust (09/22). Dr. McBride is supported by the Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine. Dr. Joshi is supported by Chief Scientist Office (ETM/160). Dr. van Beek is supported by the Scottish Imaging Network e a Platform of Scientific Excellence. The work of Dr. Rudd is part-supported by the NIHR Cambridge Biomedical Research Centre, the British Heart Foundation and the Wellcome Trust. Dr. Newby is supported by the British Heart Foundation (CH/09/002). The Wellcome Trust Clinical Research Facility and the Clinical Research Imaging Centre are supported by National Health Service Research Scotland through National Health Service Lothian.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.ejvs.2015.12.01