Comparative performance of the new Aptima HIV-1 Quant Dx assay with three commercial PCR-based HIV-1 RNA quantitation assays

AbstractBackgroundQuantitative measurement of HIV-1 RNA levels in plasma (‘viral load’) plays a central role in clinical management. The choice of assay platform can influence results and treatment decisions.ObjectiveTo compare the analytical performance of the new TMA-based Hologic Aptima® HIV-1 Quant Dx assay with that of three PCR-based assays: Abbott RealTime HIV-1, Qiagen Artus® HI Virus-1 QS-RGQ, and Roche CAP/CTM HIV-1 Test v2.Study designAssay performance was evaluated using Acrometrix HIV-1 RNA Standard panels; the 3rd WHO HIV-1 RNA International Standard (12–500copies/ml; 6 dilutions; 9 replicates); and plasma samples from 191 HIV-positive patients.ResultsAptima showed high (>0.99) precision, accuracy and concordance with the Acrometrix Standards across a wide dynamic range (2.0–6.7 log10copies/ml). Variance caused up to 2.1 (Aptima), 1.7 (RealTime), 7.5 (Artus), and 1.9 (CAP/CTM) fold changes in the International Standard quantifications at 50–500copies/ml. HIV-1 RNA detection rates in plasma samples were 141/191 (74%), 119/191 (62%), 108/191 (57%), and 145/191 (76%) for Aptima, RealTime, Artus and CAP/CTM, respectively. For categorising samples either side of 50 copies/ml, Aptima had excellent agreement with RealTime (kappa 0.92; 95% CI 0.87–0.98); lowest agreement was with Artus (kappa 0.79; 95%CI 0.70–0.88). Aptima quantifications were mean 0.12 and 0.06 log10copies/ml higher compared with RealTime and CAP/CTM, respectively, and 0.05 log10copies/ml lower compared with Artus. Limits of agreement were narrowest when comparing Aptima to RealTime.ConclusionsThe new Aptima HIV assay is sensitive, precise, and accurate. HIV assays exhibit discordance at low HIV-1 RNA copy numbers

Abdominal aortic aneurysm clinical practice guidelines: a methodological assessment using the AGREE II instrument.

OBJECTIVES: Abdominal aortic aneurysm (AAA) clinical practice guidelines (CPGs) provide evidence-based information on patient management; however, methodological differences exist in the development of CPGs. This study examines the methodological quality of AAA CPGs using a validated assessment tool. METHODS: Medline, EMBASE and online CPG databases were searched from 1946 to 31 October 2021. Full-text, English language, evidence-based AAA CPGs were included. Consensus-based CPGs, summaries of CPGs or CPGs which were only available on purchase were excluded. Five reviewers assessed their quality using the Appraisal of Guidelines for Research and Evaluation II instrument. An overall guideline assessment scaled score of ≥80% was considered as the threshold to recommend CPG use in clinical practice. RESULTS: Seven CPGs were identified. Scores showed good inter-reviewer reliability (intraclass correlation coefficient 0.943, 95% CI 0.915 to 0.964). On average, CPGs performed adequately with mean scaled scores of over 50% in all domains. However, between CPGs, significant methodological heterogeneity was observed in all domains. Four CPGs scored ≥80% (European Society of Cardiology, the Society of Vascular Surgery, the European Society of Vascular Surgery and the National Institute of Health and Care Excellence), supporting their use in clinical practice. CONCLUSIONS: Four CPGs were considered of adequate methodological quality to recommend their use in clinical practice; nonetheless, these still showed areas for improvement, potentially through performing economic analysis and trial application of recommendations. A structured approach employing validated CPG creation tools should be used to improve rigour of AAA CPGs. Future work should also evaluate recommendation accuracy using validated appraisal tools

Human Skeletal myopathy myosin mutations disrupt myosin head sequestration

Myosin heavy chains encoded by MYH7 and MYH2 are abundant in human skeletal muscle, and important for muscle contraction. However, it is unclear how mutations in these genes disrupt myosin structure and function leading to skeletal muscle myopathies termed myosinopathies. Here, we used multiple approaches to analyse the effects of common MYH7 and MYH2 mutations in the light meromyosin region of myosin (LMM). Analyses of expressed and purified MYH7 and MYH2 LMM mutant proteins combined with in-silico modelling showed that myosin coiled-coil structure and packing of filaments in vitro are commonly disrupted. Using muscle biopsies from patients, and Mant-ATP chase protocols to estimate the proportion of myosin heads that were super-relaxed, together with X-ray diffraction measurements to estimate myosin head order we found that basal myosin ATP consumption was increased and the myosin super-relaxed state was decreased in vivo. In addition, myofibre mechanics experiments to investigate contractile function showed myofibre contractility was not affected. These findings indicate that the structural remodelling associated with LMM mutations induces a pathogenic state in which formation of shutdown heads is impaired, thus increasing myosin head ATP demand in the filaments, rather than affecting contractility. These key findings will help design future therapies for myosinopathies

The early-type galaxies NGC 1407 and NGC 1400 - II: star formation and chemical evolutionary history

We present a possible star formation and chemical evolutionary history for two early-type galaxies NGC 1407 and NGC 1400. They are the two brightest galaxies of the NGC 1407 (or Eridanus-A) group, one of the 60 groups studied as part of the Group Evolution Multi-wavelength Study (GEMS). Our analysis is based on new high signal-to-noise spatially resolved integrated spectra obtained at the ESO 3.6m telescope, out to 0.6 (NGC 1407) and 1.3 (NGC 1400) effective radii. Using Lick/IDS indices we estimate luminosity-weighted ages, metallicities and $\alpha$-element abundance ratios. Colour radial distributions from HST/ACS and Subaru Suprime-Cam multi-band wide-field imaging are compared to colours predicted from spectroscopically determinated ages and metallicities using single stellar population models. The galaxies formed over half of their mass in a single short-lived burst of star formation (> 100 M(sun)/year) at redshift z>5. This likely involved an outside-in mechanism with supernova-driven galactic winds, as suggested by the flatness of the alpha-element radial profiles and the strong negative metallicity gradients. Our results support the predictions of the revised version of the monolithic collapse model for galaxy formation and evolution. We speculate that, since formation the galaxies have evolved quiescently and that we are witnessing the first infall of NGC 1400 in the group.Comment: 14 pages, 9 tables, 6 figures, Accepted for publication in MNRA

The early-type galaxies NGC 1407 and NGC 1400 - I: spatially resolved radial kinematics and surface photometry

This is the first paper of a series focused on investigating the star formation and evolutionary history of the two early-type galaxies NGC 1407 and NGC 1400. They are the two brightest galaxies of the NGC 1407 (or Eridanus-A) group, one of the 60 groups studied as part of the Group Evolution Multi-wavelength Study (GEMS). Here we present new high signal-to-noise long-slit spectroscopic data obtained at the ESO 3.6m telescope and high-resolution multi-band imaging data from the HST/ACS and wide-field imaging from Subaru Suprime-Cam. We spatially resolved integrated spectra out to 0.6 (NGC 1407) and 1.3 (NGC 1400) effective radii. The radial profiles of the kinematic parameters v(rot), sigma, h3 and h4 are measured. The surface brightness profiles are fitted to different galaxy light models and the colour distributions analysed. The multi-band images are modelled to derive isophotal shape parameters and residual galaxy images. The parameters from the surface brightness profile fitting are used to estimate the mass of the possible central supermassive black hole in NGC 1407. The galaxies are found to be rotationally supported and to have a flat core in the surface brightness profiles. Elliptical isophotes are observed at all radii and no fine structures are detected in the residual galaxy images. From our results we can also discard a possible interaction between NGC 1400, NGC 1407 and the group intergalactic medium. We estimate a mass of 1.03x10^9 M(sun) for the supermassive black hole in NGC 1407 galaxy.Comment: 11 pages, 6 tables, 6 figures, Accepted for publication in MNRA

Evaluation of the recombinant proteins RlpB and VacJ as a vaccine for protection against Glaesserella parasuis in pigs

Funder: U.S. Department of Agriculture; doi: http://dx.doi.org/10.13039/100000199Funder: Oak Ridge Institute for Science and Education; doi: http://dx.doi.org/10.13039/100006229Funder: Department for Environment, Food and Rural Affairs; doi: http://dx.doi.org/10.13039/501100000277Abstract: Background: Glaesserella parasuis, the causative agent of Glӓsser’s disease, is widespread in swine globally resulting in significant economic losses to the swine industry. Prevention of Glӓsser’s disease in pigs has been plagued with an inability to design broadly protective vaccines, as many bacterin based platforms generate serovar or strain specific immunity. Subunit vaccines are of interest to provide protective immunity to multiple strains of G. parasuis. Selected proteins for subunit vaccination should be widespread, highly conserved, and surface exposed. Results: Two candidate proteins for subunit vaccination (RlpB and VacJ) against G. parasuis were identified using random mutagenesis and an in vitro organ culture system. Pigs were vaccinated with recombinant RlpB and VacJ, outer membrane proteins with important contributions to cellular function and viability. Though high antibody titers to the recombinant proteins and increased interferon-γ producing cells were found in subunit vaccinated animals, the pigs were not protected from developing systemic disease. Conclusions: It appears there may be insufficient RlpB and VacJ exposed on the bacterial surface for antibody to bind, preventing high RlpB and VacJ specific antibody titers from protecting animals from G. parasuis. Additionally, this work confirms the importance of utilizing the natural host species when assessing the efficacy of vaccine candidates

Evaluation of the recombinant proteins RlpB and VacJ as a vaccine for protection against Glaesserella parasuis in pigs

Funder: U.S. Department of Agriculture; doi: http://dx.doi.org/10.13039/100000199Funder: Oak Ridge Institute for Science and Education; doi: http://dx.doi.org/10.13039/100006229Funder: Department for Environment, Food and Rural Affairs; doi: http://dx.doi.org/10.13039/501100000277Abstract: Background: Glaesserella parasuis, the causative agent of Glӓsser’s disease, is widespread in swine globally resulting in significant economic losses to the swine industry. Prevention of Glӓsser’s disease in pigs has been plagued with an inability to design broadly protective vaccines, as many bacterin based platforms generate serovar or strain specific immunity. Subunit vaccines are of interest to provide protective immunity to multiple strains of G. parasuis. Selected proteins for subunit vaccination should be widespread, highly conserved, and surface exposed. Results: Two candidate proteins for subunit vaccination (RlpB and VacJ) against G. parasuis were identified using random mutagenesis and an in vitro organ culture system. Pigs were vaccinated with recombinant RlpB and VacJ, outer membrane proteins with important contributions to cellular function and viability. Though high antibody titers to the recombinant proteins and increased interferon-γ producing cells were found in subunit vaccinated animals, the pigs were not protected from developing systemic disease. Conclusions: It appears there may be insufficient RlpB and VacJ exposed on the bacterial surface for antibody to bind, preventing high RlpB and VacJ specific antibody titers from protecting animals from G. parasuis. Additionally, this work confirms the importance of utilizing the natural host species when assessing the efficacy of vaccine candidates