1,275 research outputs found

    Slice-illuminated optical projection tomography

    Get PDF
    To improve the imaging performance of optical projection tomography (OPT) in live samples, we have explored a parallelized implementation of semi-confocal line illumination and detection to discriminate against scattered photons. Slice-illuminated OPT (sl-OPT) improves reconstruction quality in scattering samples by reducing interpixel crosstalk at the cost of increased acquisition time. For in vivo imaging, this can be ameliorated through the use of compressed sensing on angularly undersampled OPT data sets. Here, we demonstrate sl-OPT applied to 3D imaging of bead phantoms and live adult zebrafish

    International Study to Predict Optimized Treatment for Depression (iSPOT-D), a randomized clinical trial: Rationale and protocol

    Get PDF
    Background: Clinically useful treatment moderators of Major Depressive Disorder (MDD) have not yet been identified, though some baseline predictors of treatment outcome have been proposed. The aim of iSPOT-D is to identify pretreatment measures that predict or moderate MDD treatment response or remission to escitalopram, sertraline or venlafaxine; and develop a model that incorporates multiple predictors and moderators.Methods/Design: The International Study to Predict Optimized Treatment - in Depression (iSPOT-D) is a multi-centre, international, randomized, prospective, open-label trial. It is enrolling 2016 MDD outpatients (ages 18-65) from primary or specialty care practices (672 per treatment arm; 672 age-, sex- and education-matched healthy controls). Study-eligible patients are antidepressant medication (ADM) naïve or willing to undergo a one-week wash-out of any non-protocol ADM, and cannot have had an inadequate response to protocol ADM. Baseline assessments include symptoms; distress; daily function; cognitive performance; electroencephalogram and event-related potentials; heart rate and genetic measures. A subset of these baseline assessments are repeated after eight weeks of treatment. Outcomes include the 17-item Hamilton Rating Scale for Depression (primary) and self-reported depressive symptoms, social functioning, quality of life, emotional regulation, and side-effect burden (secondary). Participants may then enter a naturalistic telephone follow-up at weeks 12, 16, 24 and 52. The first half of the sample will be used to identify potential predictors and moderators, and the second half to replicate and confirm.Discussion: First enrolment was in December 2008, and is ongoing. iSPOT-D evaluates clinical and biological predictors of treatment response in the largest known sample of MDD collected worldwide.Trial registration: International Study to Predict Optimised Treatment - in Depression (iSPOT-D) ClinicalTrials.gov Identifier: NCT00693849. URL: http://clinicaltrials.gov/ct2/show/NCT00693849?term=International+Study+to+Predict+Optimized+Treatment+for+Depression&rank=1. © 2011 Williams et al; licensee BioMed Central Ltd

    Deconstructing Weight Management Interventions for Young Adults: Looking Inside the Black Box of the EARLY Consortium Trials.

    Get PDF
    ObjectiveThe goal of the present study was to deconstruct the 17 treatment arms used in the Early Adult Reduction of weight through LifestYle (EARLY) weight management trials.MethodsIntervention materials were coded to reflect behavioral domains and behavior change techniques (BCTs) within those domains planned for each treatment arm. The analytical hierarchy process was employed to determine an emphasis profile of domains in each intervention.ResultsThe intervention arms used BCTs from all of the 16 domains, with an average of 29.3 BCTs per intervention arm. All 12 of the interventions included BCTs from the six domains of Goals and Planning, Feedback and Monitoring, Social Support, Shaping Knowledge, Natural Consequences, and Comparison of Outcomes; 11 of the 12 interventions shared 15 BCTs in common across those six domains.ConclusionsWeight management interventions are complex. The shared set of BCTs used in the EARLY trials may represent a core intervention that could be studied to determine the required emphases of BCTs and whether additional BCTs add to or detract from efficacy. Deconstructing interventions will aid in reproducibility and understanding of active ingredients

    Derivation and External Validation of a Prediction Rule for Five-Year Mortality in Patients With Early Diffuse Cutaneous Systemic Sclerosis

    Get PDF
    OBJECTIVE: Although diffuse cutaneous systemic sclerosis (dcSSc) is associated with a reduction in life expectancy, there are no validated prognostic models for determining 5-year mortality in patients with dcSSc. The objective of this study was to derive and validate a rule for predicting 5-year mortality in patients with early dcSSc. METHODS: We studied an inception cohort of 388 US Caucasian patients with early dcSSc (<2 years from the appearance of the first symptom). Predefined baseline variables were analyzed in a stepwise logistic regression model in order to identify factors independently associated with 5-year all-cause mortality. We rounded the beta weights to the nearest integer and summed the points assigned to each variable in order to stratify patients into low-risk (<0 points), moderate-risk (1-2 points), and high-risk (≥3 points) groups. We then applied this rule to an external validation cohort of 144 Caucasian patients with early dcSSc from the Royal Free Hospital cohort and compared stratum-specific 5-year mortality. RESULTS: Six independent predictors (rounded beta weight) comprised the model: age at first visit (points allotted: -1, 0, or 1), male sex (points allotted: 0 or 1), tendon friction rubs (points allotted: 0 or 1), gastrointestinal involvement (points allotted: 0 or 1), RNA polymerase III antibodies (points allotted: 0 or 1), and anemia (points allotted: 0 or 1). The 3-level risk stratification model performed well, with no significant differences between the US derivation cohort and the UK validation cohort. CONCLUSION: We derived and externally validated, in US and UK cohorts, an easy-to-use 6-variable prediction rule that assigns low-risk, moderate-risk, and high-risk categories for 5-year mortality in patients with early dcSSc. Only history, physical examination, and basic laboratory assessments are required

    Mirroring everyday clinical practice in clinical trial design: a new concept to improve the external validity of randomized double-blind placebo-controlled trials in the pharmacological treatment of major depression

    Get PDF
    Background: Randomized, double-blind, placebo-controlled trials constitute the gold standard in clinical research when testing the efficacy of new psychopharmacological interventions in the treatment of major depression. However, the blinded use of placebo has been found to influence clinical trial outcomes and may bias patient selection. Discussion: To improve clinical trial design in major depression so as to reflect clinical practice more closely we propose to present patients with a balanced view of the benefits of study participation irrespective of their assignment to placebo or active treatment. In addition every participant should be given the option to finally receive the active medication. A research agenda is outlined to evaluate the impact of the proposed changes on the efficacy of the drug to be evaluated and on the demographic and clinical characteristics of the enrollment fraction with regard to its representativeness of the eligible population. Summary: We propose a list of measures to be taken to improve the external validity of double-blind, placebocontrolled trials in major depression. The recommended changes to clinical trial design may also be relevant for other psychiatric as well as medical disorders in which expectations regarding treatment outcome may affect the outcome itself

    Challenges of Loss to Follow-up in Tuberculosis Research.

    Get PDF
    In studies evaluating methods for diagnosing tuberculosis (TB), follow-up to verify the presence or absence of active TB is crucial and high dropout rates may significantly affect the validity of the results. In a study assessing the diagnostic performance of the QuantiFERON®-TB Gold In-Tube test in TB suspect children in Tanzania, factors influencing patient adherence to attend follow-up examinations and reasons for not attending were examined. In 160 children who attended and 102 children who did not attend scheduled 2-month follow-up baseline health characteristics, demographic data and risk factors for not attending follow-up were determined. Qualitative interviews were used to understand patient and caretakers reasons for not returning for scheduled follow-up. Being treated for active tb in the dots program (OR: 4.14; 95% CI:1.99-8.62;p-value<0.001) and receiving money for the bus fare (OR:129; 95% CI 16->100;P-value<0.001) were positive predictors for attending follow-up at 2 months, and 21/85(25%) of children not attending scheduled follow-up had died. Interviews revealed that limited financial resources, i.e. lack of money for transportation and poor communication, were related to non-adherence. Patients lost to follow-up is a potential problem for TB research. Receiving money for transportation to the hospital and communication is crucial for adherence to follow-up conducted at a study facility. Strategies to ensure follow-up should be part of any study protocol

    "Summary Page": a novel tool that reduces omitted data in research databases

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Data entry errors are common in clinical research databases. Omitted data are of particular concern because they are more common than erroneously inserted data and therefore could potentially affect research findings. However, few affordable strategies for their prevention are available.</p> <p>Methods</p> <p>We have conducted a prospective observational study of the effect of a novel tool called "<it>Summary Page</it>" on the frequency of correction of omitted data errors in a radiation oncology research database between July 2008 and March 2009. "<it>Summary Page</it>" was implemented as an optionally accessed screen in the database that visually integrates key fields in the record. We assessed the frequency of omitted data on the example of the <it>Date of Relapse </it>field. We considered the data in this field to be omitted for all records that had empty <it>Date of Relapse </it>field and evidence of relapse elsewhere in the record.</p> <p>Results</p> <p>A total of 1,156 records were updated and 200 new records were entered in the database over the study period. "<it>Summary Page</it>" was accessed for 44% of all updated records and for 69% of newly entered records. Frequency of correction of the omitted date of cancer relapse was six-fold higher in records for which "<it>Summary Page</it>" was accessed (p = 0.0003).</p> <p>Conclusions</p> <p>"<it>Summary Page</it>" was strongly associated with an increased frequency of correction of omitted data errors. Further, controlled, studies are needed to confirm this finding and elucidate its mechanism of action.</p

    Abusive Head Trauma and Mortality-An Analysis From an International Comparative Effectiveness Study of Children With Severe Traumatic Brain Injury

    Get PDF
    Objectives: Small series have suggested that outcomes after abusive head trauma are less favorable than after other injury mechanisms. We sought to determine the impact of abusive head trauma on mortality and identify factors that differentiate children with abusive head trauma from those with traumatic brain injury from other mechanisms. Design: First 200 subjects from the Approaches and Decisions in Acute Pediatric Traumatic Brain Injury Trial—a comparative effectiveness study using an observational, cohort study design. Setting: PICUs in tertiary children’s hospitals in United States and abroad. Patients: Consecutive children (age < 18 yr) with severe traumatic brain injury (Glasgow Coma Scale ≤ 8; intracranial pressure monitoring). Interventions: None. Measurements and Main Results: Demographics, injury-related scores, prehospital, and resuscitation events were analyzed. Children were dichotomized based on likelihood of abusive head trauma. A total of 190 children were included (n = 35 with abusive head trauma). Abusive head trauma subjects were younger (1.87 ± 0.32 vs 9.23 ± 0.39 yr; p < 0.001) and a greater proportion were female (54.3% vs 34.8%; p = 0.032). Abusive head trauma were more likely to 1) be transported from home (60.0% vs 33.5%; p < 0.001), 2) have apnea (34.3% vs 12.3%; p = 0.002), and 3) have seizures (28.6% vs 7.7%; p < 0.001) during prehospital care. Abusive head trauma had a higher prevalence of seizures during resuscitation (31.4 vs 9.7%; p = 0.002). After adjusting for covariates, there was no difference in mortality (abusive head trauma, 25.7% vs nonabusive head trauma, 18.7%; hazard ratio, 1.758; p = 0.60). A similar proportion died due to refractory intracranial hypertension in each group (abusive head trauma, 66.7% vs nonabusive head trauma, 69.0%). Conclusions: In this large, multicenter series, children with abusive head trauma had differences in prehospital and in-hospital secondary injuries which could have therapeutic implications. Unlike other traumatic brain injury populations in children, female predominance was seen in abusive head trauma in our cohort. Similar mortality rates and refractory intracranial pressure deaths suggest that children with severe abusive head trauma may benefit from therapies including invasive monitoring and adherence to evidence-based guidelines

    Regression of target organ damage in children and adolescents with primary hypertension

    Get PDF
    We assessed the effects of 12 months of non-pharmacological and pharmacological therapy on 24-h ambulatory blood pressure, regression of target organ damage (TOD) and metabolic abnormalities in 86 children (14.1 ± 2.4 years) with primary hypertension. Twenty-four hour systolic and diastolic blood pressure (BP) decreased (130 ± 8 vs 126 ± 8, 73 ± 7 vs 70 ± 7, p = 0.0001 and 0.004 respectively). Body mass index (BMI) did not change, but waist-to-hip (0.85 ± 0.07 vs 0.83 ± 0.05, p = 0.01) and waist-to-height ratio (WHtR; 0.49 ± 0.07 vs 0.48 ± 0.05, p = 0.008) decreased. Left ventricular mass index (LVMi; 38.5 ± 10.7 vs 35.2 ± 7.5 g/m2.7, p = 0.0001), prevalence of left ventricular hypertrophy (46.5% vs 31.4%; p = 0.0001), carotid intima-media thickness (cIMT; 0.44 ± 0.05 vs 0.42 ± 0.04 mm, p = 0.0001), wall cross sectional area (WCSA; 7.5 ± 1.3 vs 6.9 ± 1.2 mm2, p = 0.002), hsCRP (1.1 ± 1.0 vs 0.7 ± 0.7 mg/l, p = 0.002), and LDL-cholesterol (115 ± 33 vs 107 ± 26 mg/dl, p = 0.001) decreased. Patients who had lowered BP had a lower cIMT at the second examination (0.41 ± 0.04 vs 0.43 ± 0.04 mm, p = 0.04) and lower initial hsCRP values (0.9 ± 0.7 vs 1.5 ± 1.3 mg/l, p = 0.04) in comparison to non-responders. Regression analysis revealed that the main predictor of LVMi decrease was a decrease in abdominal fat expressed as a decrease in waist circumference (WC) (R2 = 0.280, β = 0.558, p = 0.005), for WCSA-SDS a decrease in WC (R2 = 0.332, β = 0.611, p = 0.009) and for a cIMT-SDS decrease the main predictor was a decrease in hsCRP concentrations (R2 = 0.137, β = 0.412, p = 0.03). Standard antihypertensive treatment lowered BP and led to regression of TOD in hypertensive children. Lean body mass increase and decrease in abdominal obesity correlated with TOD regression
    corecore