917 research outputs found

    Benefits of Incentives for Breastfeeding and Smoking cessation in pregnancy (BIBS): a mixed-methods study to inform trial design

    Get PDF
    Background: Smoking in pregnancy and/or not breastfeeding have considerable negative health outcomes for mother and baby. Aim: To understand incentive mechanisms of action for smoking cessation in pregnancy and breastfeeding, develop a taxonomy and identify promising, acceptable and feasible interventions to inform trial design. Design: Evidence syntheses, primary qualitative survey, and discrete choice experiment (DCE) research using multidisciplinary, mixed methods. Two mother-and-baby groups in disadvantaged areas collaborated throughout. Setting: UK. Participants: The qualitative study included 88 pregnant women/recent mothers/partners, 53 service providers, 24 experts/decision-makers and 63 conference attendees. The surveys included 1144 members of the general public and 497 health professionals. The DCE study included 320 women with a history of smoking. Methods: (1) Evidence syntheses: incentive effectiveness (including meta-analysis and effect size estimates), delivery processes, barriers to and facilitators of smoking cessation in pregnancy and/or breastfeeding, scoping review of incentives for lifestyle behaviours; (2) qualitative research: grounded theory to understand incentive mechanisms of action and a framework approach for trial design; (3) survey: multivariable ordered logit models; (4) DCE: conditional logit regression and the log-likelihood ratio test. Results: Out of 1469 smoking cessation and 5408 breastfeeding multicomponent studies identified, 23 smoking cessation and 19 breastfeeding studies were included in the review. Vouchers contingent on biochemically proven smoking cessation in pregnancy were effective, with a relative risk of 2.58 (95% confidence interval 1.63 to 4.07) compared with non-contingent incentives for participation (four studies, 344 participants). Effects continued until 3 months post partum. Inconclusive effects were found for breastfeeding incentives compared with no/smaller incentives (13 studies) but provider commitment contracts for breastfeeding show promise. Intervention intensity is a possible confounder. The acceptability of seven promising incentives was mixed. Women (for vouchers) and those with a lower level of education (except for breastfeeding incentives) were more likely to disagree. Those aged ≤ 44 years and ethnic minority groups were more likely to agree. Agreement was greatest for a free breast pump and least for vouchers for breastfeeding. Universal incentives were preferred to those targeting low-income women. Initial daily text/telephone support, a quitting pal, vouchers for > £20.00 per month and values up to £80.00 increase the likelihood of smoking cessation. Doctors disagreed with provider incentives. A ‘ladder’ logic model emerged through data synthesis and had face validity with service users. It combined an incentive typology and behaviour change taxonomy. Autonomy and well-being matter. Personal difficulties, emotions, socialising and attitudes of others are challenges to climbing a metaphorical ‘ladder’ towards smoking cessation and breastfeeding. Incentive interventions provide opportunity ‘rungs’ to help, including regular skilled flexible support, a pal, setting goals, monitoring and outcome verification. Individually tailored and non-judgemental continuity of care can bolster women’s capabilities to succeed. Rigid, prescriptive interventions placing the onus on women to behave ‘healthily’ risk them feeling pressurised and failing. To avoid ‘losing face’, women may disengage. Limitations: Included studies were heterogeneous and of variable quality, limiting the assessment of incentive effectiveness. No cost-effectiveness data were reported. In surveys, selection bias and confounding are possible. The validity and utility of the ladder logic model requires evaluation with more diverse samples of the target population. Conclusions: Incentives provided with other tailored components show promise but reach is a concern. Formal evaluation is recommended. Collaborative service-user involvement is importan

    Quantification of macrophage-driven inflammation during myocardial infarction with 18F-LW223, a novel TSPO radiotracer with binding independent of the rs6971 human polymorphism

    Get PDF
    Myocardial infarction (MI) is one of the leading causes of death worldwide, and inflammation is central to tissue response and patient outcomes. The 18-kDa translocator protein (TSPO) has been used in PET as an inflammatory biomarker. The aims of this study were to screen novel, fluorinated, TSPO radiotracers for susceptibility to the rs6971 genetic polymorphism using in vitro competition binding assays in human brain and heart; assess whether the in vivo characteristics of our lead radiotracer, 18F-LW223, are suitable for clinical translation; and validate whether 18F-LW223 can detect macrophage-driven inflammation in a rat MI model. Methods: Fifty-one human brain and 29 human heart tissue samples were screened for the rs6971 polymorphism. Competition binding assays were conducted with 3H-PK11195 and the following ligands: PK11195, PBR28, and our novel compounds (AB5186 and LW223). Naïve rats and mice were used for in vivo PET kinetic studies, radiometabolite studies, and dosimetry experiments. Rats underwent permanent coronary artery ligation and were scanned using PET/CT with an invasive input function at 7 d after MI. For quantification of PET signal in the hypoperfused myocardium, K1 (rate constant for transfer from arterial plasma to tissues) was used as a surrogate marker of perfusion to correct the binding potential for impaired radiotracer transfer from plasma to tissue (BPTC). Results: LW223 binding to TSPO was not susceptible to the rs6971 genetic polymorphism in human brain and heart samples. In rodents, 18F-LW223 displayed a specific uptake consistent with TSPO expression, a slow metabolism in blood (69% of parent at 120 min), a high plasma free fraction of 38.5%, and a suitable dosimetry profile (effective dose of 20.5–24.5 μSv/MBq). 18F-LW223 BPTC was significantly higher in the MI cohort within the infarct territory of the anterior wall relative to the anterior wall of naïve animals (32.7 ± 5.0 vs. 10.0 ± 2.4 cm3/mL/min, P ≤ 0.001). Ex vivo immunofluorescent staining for TSPO and CD68 (macrophage marker) resulted in the same pattern seen with in vivo BPTC analysis. Conclusion: 18F-LW223 is not susceptible to the rs6971 genetic polymorphism in in vitro assays, has favorable in vivo characteristics, and is able to accurately map macrophage-driven inflammation after MI

    Norepinephrine Augments Salmonella enterica-Induced Enteritis in a Manner Associated with Increased Net Replication but Independent of the Putative Adrenergic Sensor Kinases QseC and QseE

    Get PDF
    Stress has long been correlated with susceptibility to microbial infection. One explanation for this phenomenon is the ability of pathogens to sense and respond to host stress-related catecholamines, such as norepinephrine (NE). In Gram-negative enteric pathogens, it has been proposed that NE may facilitate growth by mediating iron supply, or it may alter gene expression by activating adrenergic sensor kinases. The aim of this work was to investigate the relative importance of these processes in a model in which NE alters the outcome of Salmonella enterica serovar Typhimurium infection. A bovine ligated ileal loop model was used to study the effect of NE on enteritis induced by S. Typhimurium and on the bacterial in vivo replication rate. Mutants lacking putative adrenergic receptor genes were assessed in the loop model, in a calf intestinal colonization model, and in vitro. S. Typhimurium-induced enteritis was significantly enhanced by addition of 5 mM NE. This effect was associated with increased net bacterial replication in the same model. Exogenous ferric iron also stimulated bacterial replication in the medium used but not transcription of enteritis-associated loci. The putative adrenergic sensors QseC and QseE were not required for NE-enhanced enteritis, intestinal colonization of calves, or NE-dependent growth in iron-restricted medium and did not influence expression or secretion of enteritis-associated virulence factors. Our findings support a role for stress-related catecholamines in modulating the virulence of enteric bacterial pathogens in vivo but suggest that bacterial adrenergic sensors may not be the vital link in such interkingdom signaling in Salmonella

    Kinetic modelling and quantification bias in small animal PET studies with [18F]AB5186, a novel 18 kDa translocator protein radiotracer

    Get PDF
    Introduction: Positron Emission Tomography (PET) imaging with selective 18 kDa translocator protein (TSPO) radiotracers has contributed to our understanding on the role of inflammation in disease development and progression. With an increasing number of rodent models of human disease and expansion of the preclinical PET imaging base worldwide, accurate quantification of longitudinal rodent TSPO PET datasets is necessary. This is particularly relevant as TSPO PET quantification relies on invasive blood sampling due to lack of a suitable tissue reference region. Here we investigate the kinetics and quantification bias of a novel TSPO radiotracer [18F]AB5186 in rats using automatic, manual and image derived input functions. Methods: [18F]AB5186 was administered intravenously and dynamic PET imaging was acquired over 2 hours. Arterial blood was collected manually to derive a population based input function or using an automatic blood sampler to derive a plasma input function. Manually sampled blood was also used to analyze the [18F]AB5186 radiometabolite profile in plasma and applied to all groups as a population based dataset. Kinetic models were used to estimate distribution volumes (VT) and [18F]AB5186 outcome measure bias was determined. Results: [18F]AB5186 distribution in rats was consistent with TSPO expression and at 2 h post-injection 50% of parent compound was still present in plasma. Population based manual sampling methods and image derived input function (IDIF) underestimated VT by ~50% and 88% compared with automatic blood sampling, respectively. The VT variability was lower when using IDIF versus arterial blood sampling methods and analysis of the Bland-Altman plots showed a good agreement between methods of analysis. Conclusion: Quantification of TSPO PET rodent data using image-derived methods, which are more amenable for longitudinal scanning of small animals, yields outcome measures with reduced variability and good agreement, albeit biased, compared with invasive blood sampling methods

    Imaging biomarker roadmap for cancer studies.

    Get PDF
    Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution

    Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: Health-related quality of life outcomes, resource utilization, and cost-effectiveness analysis

    Get PDF
    BackgroundThe Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that survival in patients with severe lower limb ischemia (rest pain, tissue loss) who survived postintervention for >2 years after initial randomization to bypass surgery (BSX) vs balloon angioplasty (BAP) was associated with an improvement in subsequent amputation-free and overall survival of about 6 and 7 months, respectively. We now compare the effect on hospital costs and health-related quality of life (HRQOL) of the BSX-first and BAP-first revascularization strategies using a within-trial cost-effectiveness analysis.MethodsWe measured HRQOL using the Vascular Quality of Life Questionnaire (VascuQol), the Short Form 36 (SF-36), and the EuroQol (EQ-5D) health outcome measure up to 3 years from randomization. Hospital use was measured and valued using United Kingdom National Health Service hospital costs over 3 years. Analysis was by intention-to-treat. Incremental cost-effectiveness ratios were estimated for cost per quality-adjusted life-year (QALY) gained. Uncertainty was assessed using nonparametric bootstrapping of incremental costs and incremental effects.ResultsNo significant differences in HRQOL emerged when the two treatment strategies were compared. During the first year from randomization, the mean cost of inpatient hospital treatment in patients allocated to BSX (34,378)wasestimatedtobeabout34,378) was estimated to be about 8469 (95% confidence interval, 2,4172,417-14,522) greater than that of patients allocated to BAP (25,909).OwingtoincreasedcostssubsequentlyincurredbytheBAPpatients,thisdifferencedecreasedattheendoffollowupto25,909). Owing to increased costs subsequently incurred by the BAP patients, this difference decreased at the end of follow-up to 5521 (45,322forBSXvs45,322 for BSX vs 39,801 for BAP) and was no longer significant. The incremental cost-effectiveness ratio of a BSX-first strategy was $184,492 per QALY gained. The probability that BSX was more cost-effective than BAP was relatively low given the similar distributions in HRQOL, survival, and hospital costs.ConclusionsAdopting a BSX-first strategy for patients with severe limb ischemia does result in a modest increase in hospital costs, with a small positive but insignificant gain in disease-specific and generic HRQOL. However, the real-world choice between BSX-first and BAP-first revascularization strategies for severe limb ischemia due to infrainguinal disease cannot depend on costs alone and will require a more comprehensive consideration of individual patient preferences conditioned by expectations of survival and other health outcomes

    Floral sonication is an innate behaviour in bumblebees that can be fine-tuned with experience in manipulating flowers

    Get PDF
    Bumblebees demonstrate an extensive capacity for learning complex motor skills to maximise exploitation of floral rewards. This ability is well studied in nectar collection but its role in pollen foraging is less well understood. Floral sonication is used by bees to extract pollen from some plant species with anthers which must be vibrated (buzzed) to release pollen. Pollen removal is determined by sonication characteristics including frequency and amplitude, and thus the ability to optimise sonication should allow bees to maximise the pollen collection. We investigated the ability of the buff-tailed bumblebee (Bombus terrestris) to modify the frequency and amplitude of their buzzes with increasing experience manipulating flowers of the buzz-pollinated plantSolanum rostratum. We analysed flight and feeding vibrations generated by naïve workers across feeding bouts. Feeding buzzes were of a higher frequency and a lower amplitude than flight buzzes. Both flight and feeding buzzes had reduced amplitudes with increasing number of foraging trips. However, the frequency of their feeding buzzes was reduced significantly more than their flight buzzes as bumblebee workers gained experience manipulating flowers. These results suggest that bumblebees are able to modify the characteristics of their buzzes with experience manipulating buzz-pollinated flowers. We discuss our findings in the context of bumblebee learning, and the current understanding of the optimal sonication characteristics for releasing pollen in buzz-pollinated species. Our results present a tantalising insight into the potential role of learning in floral sonication, paving the way for future research in this area

    Imaging biomarker roadmap for cancer studies.

    Get PDF
    Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution
    corecore