10 research outputs found

    Directed Polyvalent Display of Sulfated Ligands on Virus Nanoparticles Elicits Heparin-Like Anticoagulant Activity

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    Heparin is a sulfated glycosaminoglycan that is widely used as an anticoagulant. It is typically extracted from porcine or bovine sources to yield a heterogeneous mixture that varies both in molecular weight and in degree of sulfation. This heterogeneity, coupled with concern for contamination, has led to widespread interest in developing safer alternatives. Described herein are sulfated bacteriophage Qβ virus-like particles (VLPs) that elicit heparin-like anticoagulant activity. Sulfate groups were appended to the VLP by synthesis of single- and triple-sulfated ligands that also contained azide groups. Following conversion of VLP surface lysine groups to alkynes, the sulfated ligands were attached to the VLP via copper-catalyzed azide–alkyne cycloaddition (CuAAC). MALDI-MS analysis of the intermediate alkyne VLP indicated that the majority of the coat proteins contained 5–7 of the alkyne linkers; similar analysis of the intermediate alkyne particles conjugated to a fluorescein azide suggest that nearly the same number of attachment points (3–6) are modified via CuAAC. Analysis by SDS-PAGE with fluorescent staining indicated altered migration patterns for the various constructs: compared to the wild-type nanoparticle, the modified coat proteins appeared to migrate farther toward the positive pole in the gel, with coat proteins displaying the triple-sulfated ligand migrating significantly farther. Clotting activity analyzed by activated partial thrombin time (APTT) assay showed that the sulfated particles were able to perturb coagulation, with VLPs displaying the triple-sulfated ligand approximately as effective as heparin on a per mole basis; this activity could be partially reversed by protamine. ELISA experiments to assess the response of the complement system to the VLPs indicate that sulfating the particles may reduce complement activation

    BSR guideline on the management of adults with systemic lupus erythematosus (SLE) 2018: baseline multi-centre audit in the UK.

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    OBJECTIVES To assess the baseline care provided to patients with SLE attending UK Rheumatology units, audited against standards derived from the recently published BSR guideline for the management of adults with SLE, the NICE technology appraisal for belimumab, and NHS England's clinical commissioning policy for rituximab. METHODS SLE cases attending outpatient clinics during any 4-week period between February and June 2018 were retrospectively audited to assess care at the preceding visit. The effect of clinical environment (general vs dedicated CTD/vasculitis clinic and specialized vs non-specialized centre) were tested. Bonferroni's correction was applied to the significance level. RESULTS Fifty-one units participated. We audited 1021 episodes of care in 1003 patients (median age 48 years, 74% diagnosed >5 years ago). Despite this disease duration, 286 (28.5%) patients had active disease. Overall in 497 (49%) clinic visits, it was recorded that the patient was receiving prednisolone, including in 28.5% of visits where disease was assessed as inactive. Low documented compliance (<60% clinic visits) was identified for audit standards relating to formal disease-activity assessment, reduction of drug-related toxicity and protection against comorbidities and damage. Compared with general clinics, dedicated clinics had higher compliance with standards for appropriate urine protein quantification (85.1% vs 78.1%, P ≤ 0.001). Specialized centres had higher compliance with BILAG Biologics Register recruitment (89.4% vs 44.4%, P ≤ 0.001) and blood pressure recording (95.3% vs 84.1%). CONCLUSIONS This audit highlights significant unmet need for better disease control and reduction in corticosteroid toxicity and is an opportunity to improve compliance with national guidelines. Higher performance with nephritis screening in dedicated clinics supports wider adoption of this service-delivery model

    Estimation of the burden of shielding among a cross-section of patients attending rheumatology clinics with SLE-data from the BSR audit of systemic lupus erythematosus.

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    OBJECTIVES We aimed to estimate what proportion of people with SLE attending UK rheumatology clinics would be categorized as being at high risk from coronavirus disease 2019 (COVID-19) and therefore asked to shield, and explore what implications this has for rheumatology clinical practice. METHODS We used data from the British Society for Rheumatology multicentre audit of SLE, which included a large, representative cross-sectional sample of patients attending UK Rheumatology clinics with SLE. We calculated who would receive shielding advice using the British Society for Rheumatology's risk stratification guidance and accompanying scoring grid, and assessed whether ethnicity and history of nephritis were over-represented in the shielding group. RESULTS The audit included 1003 patients from 51 centres across all 4 nations of the UK. Overall 344 (34.3%) patients had a shielding score ≥3 and would have been advised to shield. People with previous or current LN were 2.6 (1.9-3.4) times more likely to be in the shielding group than people with no previous LN (P < 0.001). Ethnicity was not evenly distributed between the groups (chi-squared P < 0.001). Compared with White people, people of Black ethnicity were 1.9 (1.3-2.8) and Asian 1.9 (1.3-2.7) times more likely to be in the shielding group. Increased risk persisted after controlling for LN. CONCLUSION Our study demonstrates the large number of people with SLE who are likely to be shielding. Implications for clinical practice include considering communication across language and cultural differences, and ways to conduct renal assessment including urinalysis, during telephone and video consultations for patients who are shielding

    Serotype-specific detection of dengue viruses in a nonstructural protein 1-based enzyme-linked immunosorbent assay validated with a multi-national cohort

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    © 2020 Bosch et al. Background Dengue virus (DENV) infections pose one of the largest global barriers to human health. The four serotypes (DENV 1–4) present different symptoms and influence immune response to subsequent DENV infections, rendering surveillance, risk assessments, and disease control particularly challenging. Early diagnosis and appropriate clinical management is critical and can be achieved by detecting DENV nonstructural protein 1 (NS1) in serum during the acute phase. However, few NS1-based tests have been developed that are capable of differentiat-ing DENV serotypes and none are currently commercially available. Methodology/Principle findings We developed an enzyme-linked immunosorbent assay (ELISA) to distinguish DENV-1-4 NS1 using serotype-specific pairs of monoclonal antibodies. A total of 1,046 antibodies were harvested from DENV-immunized mice and screened for antigen binding affinity. ELISA clinical performance was evaluated using 408 polymerase chain reaction-confirmed dengue samples obtained from patients in Brazil, Honduras, and India. The overall sensitiv-ity of the test for pan-DENV was 79.66% (325/408), and the sensitivities for DENV-1-4 sero-typing were 79.1% (38/48), 80.41% (78/97), 100% (45/45), and 79.6% (98/123), respectively. Specificity reached 94.07–100%. Significance Our study demonstrates a robust antibody screening strategy that enabled the development of a serotype NS1-based ELISA with maximized specific and sensitive antigen binding. This sensitive and specific assay also utilized the most expansive cohort to date, and of which about half are from Latin America, a geographic region severely underrepresented in previous similar studies. This ELISA test offers potential enhanced diagnostics during the acute phase of infection to help guide patient care and disease control. These results indicate that this ELISA is a promising aid in early DENV-1-4 diagnosis and surveillance in regions of endemicity in addition to offer convenient monitoring for future vaccine interventions

    Development and validation of a rapid lateral flow E1/E2-antigen test and ELISA in patients infected with emerging Asian strain of Chikungunya virus in the Americas

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    Since its 2013 emergence in the Americas, Chikungunya virus (CHIKV) has posed a serious threat to public health. Early and accurate diagnosis of the disease, though currently lacking in clinics, is integral to enable timely care and epidemiological response. We developed a dual detection system: a CHIKV antigen E1/E2-based enzyme-linked immunosorbent assay (ELISA) and a lateral flow test using high-affinity anti-CHIKV antibodies. The ELISA was validated with 100 PCR-tested acute Chikungunya fever samples from Honduras. The assay had an overall sensitivity and specificity of 51% and 96.67%, respectively, with accuracy reaching 95.45% sensitivity and 92.03% specificity at a cycle threshold (Ct) cutoff of 22. As the Ct value decreased from 35 to 22, the ELISA sensitivity increased. We then developed and validated two lateral flow tests using independent antibody pairs. The sensitivity and specificity reached 100% for both lateral flow tests using 39 samples from Colombia and Honduras at Ct cutoffs of 20 and 27, respectively. For both lateral flow tests, sensitivity decreased as the Ct increased after 27. Because CHIKV E1/E2 are exposed in the virion surfaces in serum during the acute infection phase, these sensitive and specific assays demonstrate opportunities for early detection of this emerging human pathogen.U.S. Public Health Service (award AI100190

    Breadth of Participation in Organized and Unstructured Leisure Activities Over Time and Rural Adolescents’ Functioning

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    Discretionary time outside of school offers a distinct context that can promote adolescent development; however, potential for growth depends in part on how this time is used. In this study, person-centered analyses were used to examine patterns of breadth of participation in both organized and unstructured leisure activities among rural adolescents (N = 276, 49 % female) across grades 7, 8, and 10. Adjusting for self-selection factors, the study associated these patterns with 10th grade outcomes. Three profiles of participation emerged: consistently low breadth, consistently average breadth, and consistently high breadth of involvement in both organized and unstructured leisure activities over time. The most popular activity types across profile groups were hanging out with friends, team sports, and outdoor activities. Adolescents involved in a greater breadth of organized activities reported the greatest breadth of involvement in unstructured leisure and the best functioning. Adolescents with low breadth of involvement in both organized and unstructured leisure activities consistently showed poorer outcomes. Adolescents in the high breadth of involvement profile were engaged in all activity types at higher rates than adolescents in the average and low breadth of involvement profiles. We advocate for continued efforts to increase adolescent participation in a variety of different types of out-of-school activities

    Nurture Early for Optimal Nutrition (NEON) participatory learning and action women’s groups to improve infant feeding and practices in South Asian infants: pilot randomised trial study protocol

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    Introduction Feeding practices developed in early life can impact a child’s nutrition, growth, dental health, cognitive development and lifetime risk of chronic diseases. Substantial evidence suggests ethnic health inequalities, and non-recommended complementary infant feeding practices among UK’s South Asian (SA) population. Nurture Early for Optimal Nutrition aims to use women’s group participatory learning and action (PLA) cycles to optimise infant feeding, care and dental hygiene practices in SA infants &lt;2 years in East London.Methods and analysis A three-arm pilot feasibility cluster randomised controlled trial will assess feasibility, acceptability, costs and explore preliminary effectiveness for proposed primary outcome (ie, reporting on body mass index (BMI) z-score). Multilingual SA community facilitators will deliver the intervention, group PLA Cycle, to mothers/carers in respective ethnic/language groups. 12 wards are randomised to face-to-face PLA, online PLA and usual care arms in 1:1:1 ratio. Primary outcomes are feasibility and process measures (ie, BMI z-score, study records, feedback questionnaires, direct observation of intervention and sustainability) for assessment against Go/Stop criteria. Secondary outcomes are cluster-level and economic outcomes (ie, eating behaviour, parental feeding practices, network diffusion, children development performance, level of dental caries, general practitioner utilisation, costs, staff time). Outcomes are measured at baseline, every 2 weeks during intervention, 14 weeks and at 6 months by blinded outcome assessors where possible. This study will use concurrent mixed-methods evaluation. Quantitative analyses include descriptive summary with 95% CI and sample size calculation for the definitive trial. The intervention effect with CI will be estimated for child BMI z-score. Implementation will be evaluated qualitatively using thematic framework analysis.Ethics and dissemination Ethics approval was obtained from University College London (UCL), National Health Service (Health Research Authority (HRA) and Health and Care Research Wales (HRCW)). Results will be published in peer-reviewed journals, presented at scientific conferences/workshops with commissioners, partners and participating communities. Plain language summaries will be disseminated through community groups, websites and social media.Trial registration number IRAS-ID-296259 (ISRCTN10234623)
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