40 research outputs found

    Using molecular data for epidemiological inference: assessing the prevalence of Trypanosoma brucei rhodesiense in Tsetse in Serengeti, Tanzania

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    Background: Measuring the prevalence of transmissible Trypanosoma brucei rhodesiense in tsetse populations is essential for understanding transmission dynamics, assessing human disease risk and monitoring spatio-temporal trends and the impact of control interventions. Although an important epidemiological variable, identifying flies which carry transmissible infections is difficult, with challenges including low prevalence, presence of other trypanosome species in the same fly, and concurrent detection of immature non-transmissible infections. Diagnostic tests to measure the prevalence of T. b. rhodesiense in tsetse are applied and interpreted inconsistently, and discrepancies between studies suggest this value is not consistently estimated even to within an order of magnitude. Methodology/Principal Findings: Three approaches were used to estimate the prevalence of transmissible Trypanosoma brucei s.l. and T. b. rhodesiense in Glossina swynnertoni and G. pallidipes in Serengeti National Park, Tanzania: (i) dissection/microscopy; (ii) PCR on infected tsetse midguts; and (iii) inference from a mathematical model. Using dissection/microscopy the prevalence of transmissible T. brucei s.l. was 0% (95% CI 0–0.085) for G. swynnertoni and 0% (0–0.18) G. pallidipes; using PCR the prevalence of transmissible T. b. rhodesiense was 0.010% (0–0.054) and 0.0089% (0–0.059) respectively, and by model inference 0.0064% and 0.00085% respectively. Conclusions/Significance: The zero prevalence result by dissection/microscopy (likely really greater than zero given the results of other approaches) is not unusual by this technique, often ascribed to poor sensitivity. The application of additional techniques confirmed the very low prevalence of T. brucei suggesting the zero prevalence result was attributable to insufficient sample size (despite examination of 6000 tsetse). Given the prohibitively high sample sizes required to obtain meaningful results by dissection/microscopy, PCR-based approaches offer the current best option for assessing trypanosome prevalence in tsetse but inconsistencies in relating PCR results to transmissibility highlight the need for a consensus approach to generate meaningful and comparable data

    Bacterial Acquisition in Juveniles of Several Broadcast Spawning Coral Species

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    Coral animals harbor diverse microorganisms in their tissues, including archaea, bacteria, viruses, and zooxanthellae. The extent to which coral-bacterial associations are specific and the mechanisms for their maintenance across generations in the environment are unknown. The high diversity of bacteria in adult coral colonies has made it challenging to identify species-specific patterns. Localization of bacteria in gametes and larvae of corals presents an opportunity for determining when bacterial-coral associations are initiated and whether they are dynamic throughout early development. This study focuses on the early onset of bacterial associations in the mass spawning corals Montastraea annularis, M. franksi, M. faveolata, Acropora palmata, A. cervicornis, Diploria strigosa, and A. humilis. The presence of bacteria and timing of bacterial colonization was evaluated in gametes, swimming planulae, and newly settled polyps by fluorescence in situ hybridization (FISH) using general eubacterial probes and laser-scanning confocal microscopy. The coral species investigated in this study do not appear to transmit bacteria via their gametes, and bacteria are not detectable in or on the corals until after settlement and metamorphosis. This study suggests that mass-spawning corals do not acquire, or are not colonized by, detectable numbers of bacteria until after larval settlement and development of the juvenile polyp. This timing lays the groundwork for developing and testing new hypotheses regarding general regulatory mechanisms that control bacterial colonization and infection of corals, and how interactions among bacteria and juvenile polyps influence the structure of bacterial assemblages in corals

    Combinatorial discovery of polymers resistant to bacterial attachment

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    Bacterial attachment and subsequent biofilm formation are key challenges to the long term performance of many medical devices. Here, a high throughput approach coupled with the analysis of surface structure-property relationships using a chemometics approach has been developed to simultaneously investigate the interaction of bacteria with hundreds of polymeric materials on a microarray format. Using this system, a new group of materials comprising ester and hydrophobic moieties are identified that dramatically reduce the attachment of clinically relevant, pathogenic bacteria (Pseudomonas aeruginosa, Staphylococcus aureus and uropathogenic Escherichia coli). Hit materials coated on silicone catheters resulted in up to a 30 fold reduction in coverage compared to a commercial silver embedded catheter, which has been proven to half the incidence of clinically acquired infection. These polymers represent a new class of materials resistant to bacterial attachment that could not have been predicted from the current understanding of bacteria-surface interactions

    Assessing the efficacy of the healthy eating and lifestyle programme (HELP) compared with enhanced standard care of the obese adolescent in the community: study protocol for a randomized controlled trial

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    Background: The childhood obesity epidemic is one of the foremost UK health priorities. Childhood obesity tracks into adult life and places individuals at considerable risk for diabetes, cardiovascular disease, liver disease and other morbidities. There is widespread need for paediatric lifestyle programmes as change may be easier to accomplish in childhood than later in life. Study Design/Method: The study will evaluate the management of adolescent obesity by conducting a Medical Research Council complex intervention phase III efficacy randomised clinical trial of the Healthy Eating Lifestyle Programme within primary care. The study tests a community delivered multi-component intervention designed for adolescents developed from best practice as identified by National Institute for Health and Clinical Excellence. The hospital based pilot reduced body mass index and improved health-related quality of life. Subjects will be individually randomised to receiving either the Healthy Eating Lifestyle Programme (12 fortnightly family sessions) or enhanced standard care. Baseline and follow up assessments will be undertaken blind to allocation status. A health economic evaluation is also being conducted. 200 obese young people (13-17 years, body mass index > 98th centile for age and sex) will be recruited from primary care within the greater London area. The primary hypothesis is that a motivational and solution-focused family-based weight management programme delivered over 6 months is more efficacious in reducing body mass index in obese adolescents identified in the community than enhanced standard care. The primary outcome will be body mass index at the end of the intervention, adjusted for baseline body mass index, age and sex. The secondary hypothesis is that the Healthy Eating Lifestyle Programme is more efficacious in improving quality of life and psychological function and reducing waist circumference and cardiovascular risk factors in obese adolescents than enhanced standard care assessed at 6 and 12 months post baseline assessment. Improvement in quality of life predicts on-going lifestyle change and maximises the chances of long-term weight reduction. We will explore whether improvement in QOL may be intermediate on the pathway between the intervention and body mass index change

    A before-after implementation trial of smoking cessation guidelines in hospitalized veterans

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    Abstract Background Although most hospitalized smokers receive some form of cessation counseling during hospitalization, few receive outpatient cessation counseling and/or pharmacotherapy following discharge, which are key factors associated with long-term cessation. US Department of Veterans Affairs (VA) hospitals are challenged to find resources to implement and maintain the kind of high intensity cessation programs that have been shown to be effective in research studies. Few studies have applied the Chronic Care Model (CCM) to improve inpatient smoking cessation. Specific objectives The primary objective of this protocol is to determine the effect of a nurse-initiated intervention, which couples low-intensity inpatient counseling with sustained proactive telephone counseling, on smoking abstinence in hospitalized patients. Key secondary aims are to determine the impact of the intervention on staff nurses' attitudes toward providing smoking cessation counseling; to identify barriers and facilitators to implementation of smoking cessation guidelines in VA hospitals; and to determine the short-term cost-effectiveness of implementing the intervention. Design Pre-post study design in four VA hospitals Participants Hospitalized patients, aged 18 or older, who smoke at least one cigarette per day. Intervention The intervention will include: nurse training in delivery of bedside cessation counseling, electronic medical record tools (to streamline nursing assessment and documentation, to facilitate prescription of pharmacotherapy), computerized referral of motivated inpatients for proactive telephone counseling, and use of internal nursing facilitators to provide coaching to staff nurses practicing in non-critical care inpatient units. Outcomes The primary endpoint is seven-day point prevalence abstinence at six months following hospital admission and prolonged abstinence after a one-month grace period. To compare abstinence rates during the intervention and baseline periods, we will use random effects logistic regression models, which take the clustered nature of the data within nurses and hospitals into account. We will assess attitudes of staff nurses toward cessation counseling by questionnaire and will identify barriers and facilitators to implementation by using clinician focus groups. To determine the short-term incremental cost per quitter from the perspective of the VA health care system, we will calculate cessation-related costs incurred during the initial hospitalization and six-month follow-up period. Trial number NCT00816036http://deepblue.lib.umich.edu/bitstream/2027.42/112349/1/13012_2009_Article_190.pd

    An Updated Review of Interventions that Include Promotion of Physical Activity for Adult Men

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    The marked disparity in life expectancy between men and women suggests men are a vulnerable group requiring targeted health promotion programs. As such, there is an increasing need for health promotion strategies that effectively engage men with their health and/or illness management. Programs that promote physical activity could significantly improve the health of men. Although George et al. (Sports Med 42(3):281, 30) reviewed physical activity programs involving adult males published between 1990 and 2010, developments in men’s health have prompted the emergence of new sex- and gender-specific approaches targeting men. The purpose of this review was to: (1) extend and update the review undertaken by George et al. (Sports Med 42(3):281, 30) concerning the effectiveness of physical activity programs in males, and (2) evaluate the integration of gender-specific influences in the content, design, and delivery of men’s health promotion programs. A search of MEDLINE, CINAHL, ScienceDirect, Web of Science, PsycINFO, the Cochrane Library, and the SPORTDiscus databases for articles published between January 2010 and August 2014 was conducted. In total, 35 studies, involving evaluations of 31 programs, were identified. Findings revealed that a variety of techniques and modes of delivery could effectively promote physical activity among men. Though the majority of programs were offered exclusively to men, 12 programs explicitly integrated gender-related influences in male-specific programs in ways that recognized men’s interests and preferences. Innovations in male-only programs that focus on masculine ideals and gender influences to engage men in increasing their physical activity hold potential for informing strategies to promote other areas of men’s health

    Imaging biomarker roadmap for cancer studies.

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    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

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Acknowledgements

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    Firstly, utmost thanks to Simon King for his generosity. This thesis would never have reached fruition without his insight and guidance, and I count myself very lucky to have had someone with such an inspirational teaching style assume the role of my supervisor. Thanks also to all those who make the CSTR such a stimulating and supportive environ-ment to work in. Those deserving of a special mention include Korin Richmond for his attention to detail and willingness to discuss/share knowledge of matters ranging from computing to linguistics, through machine learning, onto pottery, politics and home-brew. Also Rob Clark for always making time to sort out my linux and system-related hiccups despite having plenty of his own work to do. Thanks to those who read all or parts of this thesis while it was in preparation – your comments and questions have been invaluable. Thanks to those who have given me useful feedback over the last years, or taken the trouble to answer queries which arose at odd times. I’ve benefited from the input of Pau
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