97 research outputs found

    Neighborhood satisfaction, functional limitations, and self-efficacy influences on physical activity in older women

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    <p>Abstract</p> <p>Background</p> <p>Perceptions of one's environment and functional status have been linked to physical activity in older adults. However, little is known about these associations over time, and even less about the possible mediators of this relationship. We examined the roles played by neighborhood satisfaction, functional limitations, self-efficacy, and physical activity in a sample of older women over a 6-month period.</p> <p>Methods</p> <p>Participants (<it>N </it>= 137, <it>M </it>age = 69.6 years) completed measures of neighborhood satisfaction, functional limitations, self-efficacy, and physical activity at baseline and again 6 months later.</p> <p>Results</p> <p>Analyses indicated that changes in neighborhood satisfaction and functional limitations had direct effects on residual changes in self-efficacy, and changes in self-efficacy were associated with changes in physical activity at 6 months.</p> <p>Conclusion</p> <p>Our findings support a social cognitive model of physical activity in which neighborhood satisfaction and functional status effects on physical activity are in part mediated by intermediate individual outcomes such as self-efficacy. Additionally, these findings lend support to the position that individual perceptions of both the environment and functional status can have prospective effects on self-efficacy cognitions and ultimately, physical activity behavior.</p

    Thermodynamics of Biomolecular Recognition

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    Thermodynamic aspects of molecular recognition have been studied using yeast phosphoglycerate kinase (PGK) and two antibiotics, ristocetin and vancomycin, as model systems. The binding of 3 natural substrates, ADP, ATP and 3-phosphoglycerate to wild-type and two mutant forms of PGK was examined using kinetic techniques and isothermal titration microcalorimetry. The latter technique was also used to investigate the binding of various ligand molecules to PGK and to study the formation of the ternary complex- PGK.3-PG.ADP. The thermodynamic parameters (Ka, Delta

    Feasibility and outcomes of Fibreoptic Endoscopic Evaluation of Swallowing following prophylactic swallowing rehabilitation in head and neck cancer

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    Objectives Investigate the feasibility and outcomes of fibreoptic endoscopic evaluation of swallowing (FEES) following a programme of prophylactic swallowing exercises in head and neck cancer (HNC) patients treated with radiotherapy. Design Prospective, single cohort, feasibility study. Setting Three head and neck cancer centres in Scotland. Participants Pre‐radiotherapy HNC patients who consented to participate in a prophylactic swallowing intervention. Outcome measures FEES recruitment and retention rates, assessment acceptability and compliance, qualitative process evaluation. Results Higher rates of recruitment and retention were achieved in centres where FEES equipment was available on site. Travel and anticipated discomfort were barriers to recruitment. Data completion was high for all rating scales, with goo d reliability. Following radiotherapy, swallowing safety significantly deteriorated for liquid boluses (p=0.005‐0.03); pharyngeal residue increased for liquid and semi‐solid boluses. Pharyngo‐laryngeal oedema was present pre‐treatment and significantly increased post‐radiotherapy (p=0.001). Patients generally reported positive experience of FEES for their own learning and establishing a baseline. Conclusions FEES is an acceptable method of assessing patients for a prophylactic swallowing intervention and offers some additional information missing from VF. Barriers have been identified and should be taken into account in order to maximise recruitment for future trials

    RNA oligomers at atomic resolution containing 1‐methylpseudouridine, an essential building block of mRNA vaccines

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    All widely used mRNA vaccines against COVID‐19 contain in their sequence 1‐methylpseudouridine (m1Ψ) instead of uridine. In this publication, we report two high resolution crystal structures (at up to 1.01 and 1.32 Å, respectively) of one such double‐stranded 12‐mer RNA sequence crystallized in two crystal forms. The structures are compared with similar structures which do not contain this modification. Additionally, the X‐ray structure of 1‐methyl‐pseudouridine itself was determined

    Elevated ferritin, mediated by IL-18 is associated with systemic inflammation and mortality in acute respiratory distress syndrome (ARDS)

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    BACKGROUND: Inflammatory subphenotypes have been identified in acute respiratory distress syndrome (ARDS). Hyperferritinaemia in sepsis is associated with hyperinflammation, worse clinical outcomes, and may predict benefit with immunomodulation. Our aim was to determine if raised ferritin identified a subphenotype in patients with ARDS. METHODS: Baseline plasma ferritin concentrations were measured in patients with ARDS from two randomised controlled trials of simvastatin (Hydroxymethylglutaryl-CoA Reductase Inhibition with Simvastatin in Acute Lung Injury to Reduce Pulmonary Dysfunction-2 (HARP-2); discovery cohort, UK) and neuromuscular blockade (ROSE; validation cohort, USA). Results were analysed using a logistic regression model with restricted cubic splines, to determine the ferritin threshold associated with 28-day mortality. RESULTS: Ferritin was measured in 511 patients from HARP-2 (95% of patients enrolled) and 847 patients (84% of patients enrolled) from ROSE. Ferritin was consistently associated with 28-day mortality in both studies and following a meta-analysis, a log-fold increase in ferritin was associated with an OR 1.71 (95% CI 1.01 to 2.90) for 28-day mortality. Patients with ferritin >1380 ng/mL (HARP-2 28%, ROSE 24%) had a significantly higher 28-day mortality and fewer ventilator-free days in both studies. Mediation analysis, including confounders (acute physiology and chronic health evaluation-II score and ARDS aetiology) demonstrated a statistically significant contribution of interleukin (IL)-18 as an intermediate pathway between ferritin and mortality. CONCLUSIONS: Ferritin is a clinically useful biomarker in ARDS and is associated with worse patient outcomes. These results provide support for prospective interventional trials of immunomodulatory agents targeting IL-18 in this hyperferritinaemic subgroup of patients with ARDS

    Cardiorespiratory fitness levels and body mass index of pre-adolescent children and older adults during the COVID-19 pandemic

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    IntroductionThe social and behavioral effects of the COVID-19 pandemic have impacted the health and physiology of most people, including those never diagnosed with COVID-19. While the impact of the pandemic has been felt across the lifespan, its effects on cardiorespiratory fitness (commonly considered a reflection of total body health) of older adults and children may be particularly profound due to social distancing and stay-at-home advisories, as well as the closure of sport facilities and non-essential businesses. The objective of this investigation was to leverage baseline data from two ongoing clinical trials to determine if cardiorespiratory fitness and body mass index were different during COVID-19 relative to before COVID-19 in older adults and children.MethodsHealthy older individuals (N = 593; 65–80 years) and 200 typically developing children (8–10 years) completed a graded maximal exercise test and had their height and weight measured.ResultsResults revealed that older adults and children tested during COVID-19 had significantly lower cardiorespiratory fitness levels than those tested before COVID-19 shutdowns (older adults: 30% lower; children: 53% lower; p's ≤ 0.001). In addition, older adults and children tested during COVID-19 had significantly higher BMI (older adults: 31.34 ± 0.57 kg/m2, p = 0.004; children: 19.27 ± 0.44 kg/m2, p = 0.05) than those tested before COVID-19 shutdowns (older adults: 29.51 ± 0.26 kg/m2, children: 18.13 ± 0.35 kg/m2). However, these differences in BMI did not remain significant when controlling for cardiorespiratory fitness.DiscussionResults from this investigation indicate that the COVID-19 pandemic, and behavior changes taken to reduce potential exposure, may have led to lower cardiorespiratory fitness levels in older adults and children, as well as higher body mass index. These findings provide relevant public health information as lower cardiorespiratory fitness levels and higher body mass indexes recorded during the pandemic could have far-reaching and protracted health consequences. Public health guidance is needed to encourage physical activity to maintain cardiorespiratory fitness and healthy body composition.Clinical trial registrationOlder adults: https://clinicaltrials.gov/ct2/show/NCT02875301, identifier: NCT02875301; Children: https://clinicaltrials.gov/ct2/show/NCT03592238, identifier: NCT03592238

    Structural Basis of Gate-DNA Breakage and Resealing by Type II Topoisomerases

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    Type II DNA topoisomerases are ubiquitous enzymes with essential functions in DNA replication, recombination and transcription. They change DNA topology by forming a transient covalent cleavage complex with a gate-DNA duplex that allows transport of a second duplex though the gate. Despite its biological importance and targeting by anticancer and antibacterial drugs, cleavage complex formation and reversal is not understood for any type II enzyme. To address the mechanism, we have used X-ray crystallography to study sequential states in the formation and reversal of a DNA cleavage complex by topoisomerase IV from Streptococcus pneumoniae, the bacterial type II enzyme involved in chromosome segregation. A high resolution structure of the complex captured by a novel antibacterial dione reveals two drug molecules intercalated at a cleaved B-form DNA gate and anchored by drug-specific protein contacts. Dione release generated drug-free cleaved and resealed DNA complexes in which the DNA gate instead adopts an unusual A/B-form helical conformation with a Mg2+ ion repositioned to coordinate each scissile phosphodiester group and promote reversible cleavage by active-site tyrosines. These structures, the first for putative reaction intermediates of a type II topoisomerase, suggest how a type II enzyme reseals DNA during its normal reaction cycle and illuminate aspects of drug arrest important for the development of new topoisomerase-targeting therapeutics

    High-throughput crystallography reveals boron-containing inhibitors of a Penicillin-binding protein with di- and tricovalent binding modes

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    The effectiveness of β-lactam antibiotics is increasingly compromised by β-lactamases. Boron-containing inhibitors are potent serine-β-lactamase inhibitors, but the interactions of boron-based compounds with the penicillin-binding protein (PBP) β-lactam targets have not been extensively studied. We used high-throughput X-ray crystallography to explore reactions of a boron-containing fragment set with the PBP3 (PaPBP3). Multiple crystal structures reveal that boronic acids react with PBPs to give tricovalently linked complexes bonded to Ser294, Ser349, and Lys484 of PaPBP3; benzoxaboroles react with PaPBP3 via reaction with two nucleophilic serines (Ser294 and Ser349) to give dicovalently linked complexes; and vaborbactam reacts to give a monocovalently linked complex. Modifications of the benzoxaborole scaffold resulted in a moderately potent inhibition of PaPBP3, though no antibacterial activity was observed. Overall, the results further evidence the potential for the development of new classes of boron-based antibiotics, which are not compromised by β-lactamase-driven resistance

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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