Prehospital Telestroke vs Paramedic Scores to Accurately Identify Stroke Reperfusion Candidates: A Cluster Randomized Controlled Trial.

BACKGROUND AND OBJECTIVE: Stroke reperfusion therapy is time critical. Improving prehospital diagnostic accuracy including the likelihood of large vessel occlusion can aid with efficient and appropriate diversion decisions to optimize onset-to-treatment time. In this study, we investigated whether prehospital telestroke improves diagnostic accuracy when compared with paramedic assessments and assessed feasibility. METHODS: We conducted a pragmatic, community-based, cluster randomized controlled trial comparing the diagnostic accuracy of telestroke assessments inside the ambulance with a modified Los Angeles Motor Scale (PASTA score). The primary outcome was the accuracy of predicting reperfusion candidates; secondary outcomes were accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of either approach to identify IV thrombolysis (IVT) and endovascular thrombectomy (EVT) candidates and true stroke patients by study group. The accuracy of telestroke and PASTA assessments was compared against in-person assessment in the emergency department and with the final diagnosis/intervention for the patient. We also monitored for technical challenges. RESULTS: We recruited 76 patients (35 telestroke and 41 PASTA) between August 2019 and September 2020. The mean age was 72.2 (±14.6) years. Telestroke was 100% (95% CI 90%-100%) and PASTA 70.7% (54.5%-83.9%) accurate in predicting reperfusion candidates compared with preimaging emergency department neurologist assessment (p < 0.001). When compared with actual reperfusion therapy administered, the predictive accuracy was 80% (63.1%-91.6%) and 60.1% (44.5%-75.8%) for telestroke and PASTA, respectively (p < 0.001). In predicting the administration of IVT, telestroke was 80% (63.1-91.6) and PASTA was 56.1% (39.8-71.5) accurate (p < 0.001). In predicting intervention with EVT, telestroke was 88.6% (73.3-96.8) and PASTA 56.1% (39.8-71.5) accurate (p = 0.005). The service model proved technically feasible and was acceptable to neurologists. DISCUSSION: Prehospital telestroke assessment is feasible, accurate, and superior to the PASTA score in predicting acute reperfusion therapies, presenting an effective option to guide prehospital diversion decisions. TRIAL REGISTRATION: The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12619001678189).anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378655&isReview=true. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that intra-ambulance telestroke evaluation has a greater diagnostic accuracy compared with the PASTA score performed by paramedics in distinguishing hyperacute stroke patients who are candidates for reperfusion therapy.

Communicating Personal Melanoma Polygenic Risk Information: Participants' Experiences of Genetic Counseling in a Community-Based Study.

Personalized polygenic risk information may be used to guide risk-based melanoma prevention and early detection at a population scale, but research on communicating this information is limited. This mixed-methods study aimed to assess the acceptability of a genetic counselor (GC) phone call in communicating polygenic risk information in the Melanoma Genomics Managing Your Risk randomized controlled trial. Participants (n = 509) received personalized melanoma polygenic risk information, an educational booklet on melanoma prevention, and a GC phone call, which was audio-recorded. Participants completed the Genetic Counseling Satisfaction Survey 1-month after receiving their risk information (n = 346). A subgroup took part in a qualitative interview post-study completion (n = 20). Survey data were analyzed descriptively using SPSS, and thematic analysis of the qualitative data was conducted using NVivo 12.0 software. The survey showed a high level of acceptability for the GC phone call (mean satisfaction score overall: 4.3 out of 5, standard deviation (SD): 0.6) with differences according to gender (mean score for women: 4.4, SD: 0.6 vs. men: 4.2, SD: 0.7; p = 0.005), health literacy (lower literacy: 4.1, SD: 0.8; average: 4.3, SD: 0.6; higher: 4.4, SD: 0.6: p = 0.02) and polygenic risk group (low risk: 4.5, SD: 0.5, SD: average: 4.3, SD: 0.7, high: 4.3, SD: 0.7; p = 0.03). During the GC phone calls, the discussion predominately related to the impact of past sun exposure on personal melanoma risk. Together our findings point to the importance of further exploring educational and support needs and preferences for communicating personalized melanoma risk among population subgroups, including diverse literacy levels.

Genes go digital: Mendelian Inheritance in Man and the genealogy of electronic publishing in biomedicine.

Mendelian Inheritance in Man (MIM), a computerized catalogue of human genetic disorders authored and maintained by cardiologist and medical genetics pioneer Victor A. McKusick, played a major part in demarcating between a novel biomedical science and the eugenic projects of racial betterment which existed prior to its emergence. Nonetheless, it built upon prior efforts to systematize genetic knowledge tied to individuals and institutions invested in eugenics. By unpacking the process of digitizing a homespun cataloguing project and charting its development into an online database, this article aims to illuminate how the institution-building efforts of one individual created an 'information order' for accessing genetic information that tacitly shaped the norms and priorities of the field toward the pursuit of specific genes associated with discernible genetic disorders. This was not by design, but rather arose through negotiation with the catalogue's users; it accommodated further changes as biomedical research displaced the Mendelian paradigm. While great effort was expended toward making sequence data available to investigators during the Human Genome Project, MIM was largely taken for granted as a 'legacy system', McKusick's own labour of love. Drawing on recent histories of biomedical data, the article suggests that the bibliographical work of curation and translation is a central feature of value production in the life sciences meriting attention in its own right.

Influence of charge sequence on the adsorption of polyelectrolytes to oppositely-charged polyelectrolyte brushes.

When a solution of polyanionic chains is placed in contact with a polycationic brush, the polyanions adsorb into the brush. We investigate the influence of the charge sequences of the free and bound species on the thermodynamics of polyelectrolyte adsorption. As model systems, we consider free and brush polyelectrolytes with either block or alternating charge sequences, and study the adsorption process using coarse-grained Langevin dynamics with implicit solvent, explicit counterions, and excess salt. Free energy, internal energy, and entropy of adsorption are computed using umbrella sampling methods. When the number of polyanions exceed the number of polycations, the brush becomes overcharged. Free chains adsorb most strongly when both free and tethered chains have a block charge sequence, and most weakly when both species have an alternating sequence. Adsorption is stronger when the free polyanion has a block sequence and the tethered polycation is alternating than in the reverse case of an alternating free polymer and a tethered block copolymer. Sequence-dependent effects are shown to be largely energetic, rather than entropic, in origin.

Rotary's PolioPlus Program: Lessons Learned, Transition Planning, and Legacy.

Hundreds of thousands of Rotary volunteers have provided support for polio eradication activities and continue to this day by making financial contributions to the Rotary PolioPlus program, participating in national immunization days, assisting with surveillance, working on local, national, and international advocacy programs for polio eradication, assisting at immunization posts and clinics, and mobilizing their communities for immunization activities (including poliovirus and other vaccines) and other health benefits. Rotary has contributed more than $1.61 billion for the global eradication of polio and has committed to provide an additional $35 million each year until 2018 (all dollar amounts represent US dollars). Its unwavering commitment to eradicate polio has been vital to the success of the program. Rotary is providing additional support for routine immunization and healthcare. When polio is finally gone, we will have the knowledge from the lessons learned with PolioPlus, such as the value of direct involvement by local Rotarians, the program for emergency funding, innovative tactics, and additional approaches for tackling other global issues, even those beyond public health. Rotary has already transitioned its grants program to include 6 areas of focus: disease prevention and treatment, water and sanitation, maternal and child health, basic education and literacy, economic and community development, and peace and conflict prevention/resolution. Funding for these grants in 2015-2016 was $71 million. The legacy of the polio program will be the complete eradication of poliovirus and the elimination of polio for all time.

Equilibration of Micelle-Polyelectrolyte Complexes: Mechanistic Differences between Static and Annealed Charge Distributions.

The role of charge density and charge annealing in polyelectrolyte complexation was investigated through systematic comparison of two micelle-polyelectrolyte systems. First, poly(dimethylaminoethyl methacrylate)-block-poly(styrene) (PDMAEMA-b-PS) micelles were complexed with poly(styrenesulfonate) (PSS) at pH values above and below the pKa of PDMAEMA to investigate the role of charge annealing in the complexation process. Second, complexes of poly(DMAEMA-stat-oligo(ethylene glycol) methyl ether methacrylate)-block-poly(styrene) (P(DMAEMA-stat-OEGMA)-b-PS) micelles with the same PSS at low pH were used to investigate how the complexation process differs when the charged sites are in fixed positions along the polymer chains. Characterization by turbidimetric titration, dynamic light scattering, and cryogenic transmission electron microscopy reveals that whether or not the charge distribution can rearrange during the complexation process significantly affects the structure and stability of the complexes. In complexes of PDMAEMA-b-PS micelles at elevated pH, in which the charge distributions can anneal, the charge sites redistribute along the corona chains upon complexation to favor more fully ion-paired configurations. This promotes rapid rearrangement to single-micelle species when the micelles are in excess but traps complexes formed with PSS in excess. In complexes with static charge distributions introduced by copolymerization of DMAEMA with neutral OEGMA monomers, on the other hand, the opposite is true: in this case, reducing the charge density promotes rearrangement to single-micelle complexes only when the polyanion is in excess. Molecular dynamics simulations show that disruption of the charge density in the corona brush reduces the barrier to rearrangement of individual ion pairs, suggesting that the inability of the brush to rearrange to form fully ion-paired complexes fundamentally alters the kinetics of complex formation and equilibration.

Particle-directed assembly of semiflexible polymer chains.

We use Langevin dynamics simulations to study aggregation of semiflexible polymers driven by attractions between polymers and spherical particles. We consider a simple model with purely repulsive polymer/polymer and particle/particle interactions but attractive polymer/particle interactions. We find a rich "phase diagram" that contains several different types of globular and rod-like aggregates with either liquid-like or crystalline structure for the particle positions. Systems that exhibit rod-like aggregates with crystalline internal order exhibit a discontinuous rod-globule transition, while systems with liquid-like internal order exhibit a smooth crossover between isotropic and elongated aggregates with increasing chain stiffness. Polymers in elongated liquid-like aggregates often adopt helical configurations that wind around the axis of the aggregate.

Sculpting bespoke mountains: Determining free energies with basis expansions.

The intriguing behavior of a wide variety of physical systems, ranging from amorphous solids or glasses to proteins, is a direct manifestation of underlying free energy landscapes riddled with local minima separated by large barriers. Exploring such landscapes has arguably become one of statistical physics's great challenges. A new method is proposed here for uniform sampling of rugged free energy surfaces. The method, which relies on special Green's functions to approximate the Dirac delta function, improves significantly on existing simulation techniques by providing a boundary-agnostic approach that is capable of mapping complex features in multidimensional free energy surfaces. The usefulness of the proposed approach is established in the context of a simple model glass former and model proteins, demonstrating improved convergence and accuracy over existing methods.

Repeated nebulisation of non-viral CFTR gene therapy in patients with cystic fibrosis: a randomised, double-blind, placebo-controlled, phase 2b trial.

BACKGROUND: Lung delivery of plasmid DNA encoding the CFTR gene complexed with a cationic liposome is a potential treatment option for patients with cystic fibrosis. We aimed to assess the efficacy of non-viral CFTR gene therapy in patients with cystic fibrosis. METHODS: We did this randomised, double-blind, placebo-controlled, phase 2b trial in two cystic fibrosis centres with patients recruited from 18 sites in the UK. Patients (aged ≥12 years) with a forced expiratory volume in 1 s (FEV1) of 50-90% predicted and any combination of CFTR mutations, were randomly assigned, via a computer-based randomisation system, to receive 5 mL of either nebulised pGM169/GL67A gene-liposome complex or 0.9% saline (placebo) every 28 days (plus or minus 5 days) for 1 year. Randomisation was stratified by % predicted FEV1 (<70 vs ≥70%), age (<18 vs ≥18 years), inclusion in the mechanistic substudy, and dosing site (London or Edinburgh). Participants and investigators were masked to treatment allocation. The primary endpoint was the relative change in % predicted FEV1. The primary analysis was per protocol. This trial is registered with ClinicalTrials.gov, number NCT01621867. FINDINGS: Between June 12, 2012, and June 24, 2013, we randomly assigned 140 patients to receive placebo (n=62) or pGM169/GL67A (n=78), of whom 116 (83%) patients comprised the per-protocol population. We noted a significant, albeit modest, treatment effect in the pGM169/GL67A group versus placebo at 12 months' follow-up (3.7%, 95% CI 0.1-7.3; p=0.046). This outcome was associated with a stabilisation of lung function in the pGM169/GL67A group compared with a decline in the placebo group. We recorded no significant difference in treatment-attributable adverse events between groups. INTERPRETATION: Monthly application of the pGM169/GL67A gene therapy formulation was associated with a significant, albeit modest, benefit in FEV1 compared with placebo at 1 year, indicating a stabilisation of lung function in the treatment group. Further improvements in efficacy and consistency of response to the current formulation are needed before gene therapy is suitable for clinical care; however, our findings should also encourage the rapid introduction of more potent gene transfer vectors into early phase trials. FUNDING: Medical Research Council/National Institute for Health Research Efficacy and Mechanism Evaluation Programme.

Secondary Structure of Rat and Human Amylin across Force Fields.

The aggregation of human amylin has been strongly implicated in the progression of Type II diabetes. This 37-residue peptide forms a variety of secondary structures, including random coils, α-helices, and ß-hairpins. The balance between these structures depends on the chemical environment, making amylin an ideal candidate to examine inherent biases in force fields. Rat amylin differs from human amylin by only 6 residues; however, it does not form fibrils. Therefore it provides a useful complement to human amylin in studies of the key events along the aggregation pathway. In this work, the free energy of rat and human amylin was determined as a function of α-helix and ß-hairpin content for the Gromos96 53a6, OPLS-AA/L, CHARMM22/CMAP, CHARMM22*, Amberff99sb*-ILDN, and Amberff03w force fields using advanced sampling techniques, specifically bias exchange metadynamics. This work represents a first systematic attempt to evaluate the conformations and the corresponding free energy of a large, clinically relevant disordered peptide in solution across force fields. The NMR chemical shifts of rIAPP were calculated for each of the force fields using their respective free energy maps, allowing us to quantitatively assess their predictions. We show that the predicted distribution of secondary structures is sensitive to the choice of force-field: Gromos53a6 is biased towards ß-hairpins, while CHARMM22/CMAP predicts structures that are overly α-helical. OPLS-AA/L favors disordered structures. Amberff99sb*-ILDN, AmberFF03w and CHARMM22* provide the balance between secondary structures that is most consistent with available experimental data. In contrast to previous reports, our findings suggest that the equilibrium conformations of human and rat amylin are remarkably similar, but that subtle differences arise in transient alpha-helical and beta-strand containing structures that the human peptide can more readily adopt. We hypothesize that these transient states enable dynamic pathways that facilitate the formation of aggregates and, eventually, amyloid fibrils.

The safety profile of a cationic lipid-mediated cystic fibrosis gene transfer agent following repeated monthly aerosol administration to sheep.

Clinically effective gene therapy for Cystic Fibrosis has been a goal for over 20 years. A plasmid vector (pGM169) that generates persistent expression and reduced host inflammatory responses in mice has raised prospects for translation to the clinic. The UK CF Gene Therapy Consortium is currently evaluating long-term repeated delivery of pGM169 complexed with the cationic lipid GL67A in a large Multidose Trial. This regulatory-compliant evaluation of aerosol administration of nine doses of pGM169/GL67A at monthly intervals, to the sheep lung, was performed in preparation for the Multidose Trial. All sheep tolerated treatment well with no adverse effects on haematology, serum chemistry, lung function or histopathology. Acute responses were observed in relation to bronchoalveolar cellularity comprising increased neutrophils and macrophage numbers 1 day post-delivery but these increases were transient and returned to baseline. Importantly there was no cumulative inflammatory effect or lung remodelling with successive doses. Molecular analysis confirmed delivery of pGM169 DNA to the airways and pGM169-specific mRNA was detected in bronchial brushing samples at day 1 following doses 1, 5 and 9. In conclusion, nine doses of pGM169/GL67A were well tolerated with no significant evidence of toxicity that would preclude adoption of a similar strategy in CF patients.

A boundary correction algorithm for metadynamics in multiple dimensions.

Metadynamics is an efficient method for simulation of the free energy of many-particle systems. Over the last several years it has been applied to study a wide variety of systems, ranging from simple fluids to biological macromolecules. The method relies on uniform sampling along specified collective variables or order parameters. Such order parameters, however, are often bounded, and metadynamics algorithms as originally developed suffer from systematic errors at the corresponding boundaries. While several approaches have been proposed in the past to correct these errors for unidimensional systems, no method exists to fully correct these errors in multi-dimensional systems at points where multiple boundaries meet. Here we present a correction scheme that circumvents this limitation.

Parallel ß-sheet vibrational couplings revealed by 2D IR spectroscopy of an isotopically labeled macrocycle: quantitative benchmark for the interpretation of amyloid and protein infrared spectra.

Infrared spectroscopy is playing an important role in the elucidation of amyloid fiber formation, but the coupling models that link spectra to structure are not well tested for parallel ß-sheets. Using a synthetic macrocycle that enforces a two stranded parallel ß-sheet conformation, we measured the lifetimes and frequency for six combinations of doubly (13)C═(18)O labeled amide I modes using 2D IR spectroscopy. The average vibrational lifetime of the isotope labeled residues was 550 fs. The frequencies of the labels ranged from 1585 to 1595 cm(-1), with the largest frequency shift occurring for in-register amino acids. The 2D IR spectra of the coupled isotope labels were calculated from molecular dynamics simulations of a series of macrocycle structures generated from replica exchange dynamics to fully sample the conformational distribution. The models used to simulate the spectra include through-space coupling, through-bond coupling, and local frequency shifts caused by environment electrostatics and hydrogen bonding. The calculated spectra predict the line widths and frequencies nearly quantitatively. Historically, the characteristic features of ß-sheet infrared spectra have been attributed to through-space couplings such as transition dipole coupling. We find that frequency shifts of the local carbonyl groups due to nearest neighbor couplings and environmental factors are more important, while the through-space couplings dictate the spectral intensities. As a result, the characteristic absorption spectra empirically used for decades to assign parallel ß-sheet secondary structure arises because of a redistribution of oscillator strength, but the through-space couplings do not themselves dramatically alter the frequency distribution of eigenstates much more than already exists in random coil structures. Moreover, solvent exposed residues have amide I bands with >20 cm(-1) line width. Narrower line widths indicate that the amide I backbone is solvent protected inside the macrocycle. This work provides calculated and experimentally verified couplings for parallel ß-sheets that can be used in structure-based models to simulate and interpret the infrared spectra of ß-sheet containing proteins and protein assemblies, such as amyloid fibers.

Dimerization of helical ß-peptides in solution.

Molecular simulations are used to examine the aggregation behavior of several ß-peptides in explicit water. The particular peptides considered here adopt a helical, rodlike conformation in aqueous solution. Four distinct molecular sequences are considered. Earlier experimental studies have revealed the formation of ordered and disordered aggregates for such molecules, depending on sequence. The simulations reported here, which are conducted by resorting to metadynamics techniques, lead to free energy surfaces for dimerization of the peptides in water as a function of separation and relative orientation. Such surfaces are used to identify the molecular origins for the behaviors observed in the experiments.

Effect of trehalose on the interaction of Alzheimer's Aß-peptide and anionic lipid monolayers.

The interaction of amyloid ß-peptide (Aß) with cell membranes is believed to play a central role in the pathogenesis of Alzheimer's disease. In particular, recent experimental evidence indicates that bilayer and monolayer membranes accelerate the aggregation and amyloid fibril formation rate of Aß. Understanding that interaction could help develop therapeutic strategies for treatment of the disease. Trehalose, a disaccharide of glucose, has been shown to be effective in preventing the aggregation of numerous proteins. It has also been shown to delay the onset of certain amyloid-related diseases in a mouse model. Using Langmuir monolayers and molecular simulations of the corresponding system, we study several thermodynamic and kinetic aspects of the insertion of Aß peptide into DPPG monolayers in water and trehalose subphases. In the water subphase, the insertion of the Aß peptide into the monolayer exhibits a lag time which decreases with increasing temperature of the subphase. In the presence of trehalose, the lag time is completely eliminated and peptide insertion is completed within a shorter time period compared to that observed in pure water. Molecular simulations show that more peptide is inserted into the monolayer in the water subphase, and that such insertion is deeper. The peptide at the monolayer interface orients itself parallel to the monolayer, while it inserts with an angle of 50° in the trehalose subphase. Simulations also show that trehalose reduces the conformational change that the peptide undergoes when it inserts into the monolayer. This observation helps explain the experimentally observed elimination of the lag time by trehalose and the temperature dependence of the lag time in the water subphase.

Introducing Blackboard: an electronic learning platform.

Blackboard, an internet-based platform for teaching and learning, was introduced to students on the preregistration nursing programme at Northumbria University. Although clear educational advantages were identified, there were also potential pitfalls.