Apelin peptides are the cognate ligands for the G-protein coupled receptor APJ, with functions in the cardiovascular and central nervous systems, in glucose metabolism and as a human immunodeficiency virus (HIV-1) coreceptor. Apelin is found in 13-36 residue forms in vivo. The structures of five isoforms of apelin at physiological versus low (5-6 degrees C) temperature are compared here using circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy, demonstrating increased structure at low temperature. Far-ultraviolet (UV) CD spectra are predominantly random coil for apelin isoforms, but are convoluted by unusual bands from the C-terminal phenylalanine side chain. These bands, assigned using F13A-apelin-13, are accentuated at 5 degrees C and imply conformational restriction. At 35 degrees C, the R6-L9 region of apelin-17 is well structured, consistent with previous mutagenesis results showing necessity of this segment for apelin-APJ binding and activation. At 5 degrees C, R6-L9 retains its structuring while the functionally critical C-terminal G13-F17 region also becomes highly structured. Type IV beta-turns and some polyproline-II structure alongside F17 side chain motional reduction correlate well with CD spectral properties. Cis-trans peptide bond isomerization at P14 and P16 produces two sequentially assignable conformers (both trans:both cis approximately 4:1) alongside less populated conformers. Chemical shift assignment of apelin-12, -13 and pyroglutamate-apelin-13 implies highly similar structuring and the same isomerization at the C-terminus. Based on the apelin-17 structure, a two-step binding and activation mechanism is hypothesized.
SummaryIntroductionWe integrated two factors, demographic population shifts and changes in prevalence of disease, to predict future trends in demand for hand surgery in England, to facilitate workforce planning.MethodsWe analysed Hospital Episode Statistics data for Dupuytren's disease, carpal tunnel syndrome, cubital tunnel syndrome, and trigger finger from 1998 to 2011. Using linear regression, we estimated trends in both diagnosis and surgery until 2030. We integrated this regression with age specific population data from the Office for National Statistics in order to estimate how this will contribute to a change in workload over time.ResultsThere has been a significant increase in both absolute numbers of diagnoses and surgery for all four conditions. Combined with future population data, we calculate that the total operative burden for these four conditions will increase from 87,582 in 2011 to 170,166 (95% confidence interval 144,517–195,353) in 2030.DiscussionThe prevalence of these diseases in the ageing population, and increasing prevalence of predisposing factors such as obesity and diabetes, may account for the predicted increase in workload. The most cost effective treatments must be sought, which requires high quality clinical trials. Our methodology can be applied to other sub-specialties to help anticipate the need for future service provision.
IntroductionBurn registers can provide high-quality clinical data that can be used for surveillance, research, planning service provision and clinical quality assessment. Many countrywide and intercountry burn registers now exist. The variables collected by burn registers are not standardised internationally. Few international burn register data comparisons are completed beyond basic morbidity and mortality statistics. Data comparisons across registers require analysis of homogenous variables. Little work has been done to understand whether burn registers have sufficiently similar variables to enable useful comparisons. The aim of this project is to compare the variables collected in countrywide and intercountry burn registers internationally to understand their similarities and differences.Methods and analysisBurn register custodians will be invited to participate in the study and to share their register data dictionaries. Study objectives are to compare patient inclusion and exclusion criteria of each participating burn register; determine which variables are collected by each register, and if variables are required or optional, identify common variable themes; and compare a sample of variables to understand how they are defined and measured. All variable names will be extracted from each register and common themes will be identified. Detailed information will be extracted for a sample of variables to give a deeper insight into similarities and differences between registers.Ethics and disseminationNo patient data will be used in this project. Permission to use each register’s data dictionary will be sought from respective register custodians. Results will be presented at international meetings and published in open access journals. These results will be of interest to register custodians and researchers wishing to explore international data comparisons, and countries wishing to establish their own burn register.
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