Quantification of coronary artery calcium by electron beam computed tomography for determination of severity of angiographic coronary artery disease in younger patients

Objectives.This study attempted to 1) evaluate five quantitative measures of coronary artery calcium and determine which best agreed with coronary artery disease severity at angiography; and 2) determine optimal quantity cutpoints to distinguish among no, mild and significant disease.Background.Coronary artery calcium identified noninvasively by electron beam computed tomography is a sensitive marker for atherosclerosis. Quantitative assessments of calcium could distinguish among patients with no, mild and significant disease in clinical, screening and research settings.Methods.One hundred sixty patients, 23 to 59 years old, underwent coronary angiography and electron beam computed tomography. Coronary artery calciumwas defined as dense (> 130 Hounsfield units) foci ≥2 mm2on the tomogram. Regression and receiver operating characteristic analyses were used to evaluate five quantitative measures of calcium as predictors of the largest stenosis in the coronary arteries and to identify optimal cutpoints for distinguishing among disease categories. No diseasewas defined as no stenosis, mild diseaseas 10% to 49% diameter stenosis in one or more major branches and significant diseaseas ≥ 50% diameter stenosis in one or more major branches.Results.All measures evaluated performed well. With calcific area as the quantitative measure, the best cutpoint for discriminating between patients with and without disease was the presence of calcium: sensitivity 81%, specificity 86% and overall accuracy 83%. The best cutpoint for discriminating between patients with and without significant disease was 18 mm2: sensitivity 86%, specificity 81% and accuracy 83%.Conclusions.Because the ranges of calcium quantity overlapped across disease categories, no cutpoints would distinguish among categories with absolute certainty. However, selected cutpoints could rule out disease in most healthy subjects and identify most patients with significant disease

Constraints on the perturbed mutual motion in Didymos due to impact-induced deformation of its primary after the DART impact

Binary near-Earth asteroid (65803) Didymos is the target of the proposed NASA Double Asteroid Redirection Test (DART), part of the Asteroid Impact & Deflection Assessment (AIDA) mission concept. In this mission, the DART spacecraft is planned to impact the secondary body of Didymos, perturbing mutual dynamics of the system. The primary body is currently rotating at a spin period close to the spin barrier of asteroids, and materials ejected from the secondary due to the DART impact are likely to reach the primary. These conditions may cause the primary to reshape, due to landslides, or internal deformation, changing the permanent gravity field. Here, we propose that if shape deformation of the primary occurs, the mutual orbit of the system would be perturbed due to a change in the gravity field. We use a numerical simulation technique based on the full two-body problem to investigate the shape effect on the mutual dynamics in Didymos after the DART impact. The results show that under constant volume, shape deformation induces strong perturbation in the mutual motion. We find that the deformation process always causes the orbital period of the system to become shorter. If surface layers with a thickness greater than ~0.4 m on the poles of the primary move down to the equatorial region due to the DART impact, a change in the orbital period of the system and in the spin period of the primary will be detected by ground-based measurement.Comment: 8 pages, 7 figures, 2 tables, accepted for publication in MNRA

The association of cold weather and all-cause and cause-specific mortality in the island of Ireland between 1984 and 2007

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This article has been made available through the Brunel Open Access Publishing Fund.Background This study aimed to assess the relationship between cold temperature and daily mortality in the Republic of Ireland (ROI) and Northern Ireland (NI), and to explore any differences in the population responses between the two jurisdictions. Methods A time-stratified case-crossover approach was used to examine this relationship in two adult national populations, between 1984 and 2007. Daily mortality risk was examined in association with exposure to daily maximum temperatures on the same day and up to 6 weeks preceding death, during the winter (December-February) and cold period (October-March), using distributed lag models. Model stratification by age and gender assessed for modification of the cold weather-mortality relationship. Results In the ROI, the impact of cold weather in winter persisted up to 35 days, with a cumulative mortality increase for all-causes of 6.4% (95%CI=4.8%-7.9%) in relation to every 1oC drop in daily maximum temperature, similar increases for cardiovascular disease (CVD) and stroke, and twice as much for respiratory causes. In NI, these associations were less pronounced for CVD causes, and overall extended up to 28 days. Effects of cold weather on mortality increased with age in both jurisdictions, and some suggestive gender differences were observed. Conclusions The study findings indicated strong cold weather-mortality associations in the island of Ireland; these effects were less persistent, and for CVD mortality, smaller in NI than in the ROI. Together with suggestive differences in associations by age and gender between the two Irish jurisdictions, the findings suggest potential contribution of underlying societal differences, and require further exploration. The evidence provided here will hope to contribute to the current efforts to modify fuel policy and reduce winter mortality in Ireland

Mortality of Youth Offenders Along a Continuum of Justice System Involvement

Introduction Black male youth are at high risk of homicide and criminal justice involvement. This study aimed to determine how early mortality among youth offenders varies based on race; gender; and the continuum of justice system involvement: arrest, detention, incarceration, and transfer to adult courts. Methods Criminal and death records of 49,479 youth offenders (ages 10–18 years at first arrest) in Marion County, Indiana, from January 1, 1999, to December 31, 2011, were examined. Statistical analyses were completed in November 2014. Results From 1999 to 2011 (aggregate exposure, 386,709 person-years), 518 youth offender deaths occurred. The most common cause of death was homicide (48.2%). The mortality rate of youth offenders was nearly 1.5 times greater than that among community youth (standardized mortality ratio, 1.48). The youth offender mortality rate varied depending on the severity of justice system involvement. Arrested youth had the lowest rate of mortality (90/100,000), followed by detained youth (165/100,000); incarcerated youth (216/100,000); and youth transferred to adult court (313/100,000). A proportional hazards model demonstrated that older age, male gender, and more severe justice system involvement 5 years post-arrest predicted shorter time to mortality. Conclusions Youth offenders face greater risk for early death than community youth. Among these, black male youth face higher risk of early mortality than their white male counterparts. However, regardless of race/ethnicity, mortality rates for youth offenders increase as youth involvement in the justice system becomes more protracted and severe. Thus, justice system involvement is a significant factor to target for intervention

First clinical trial of nitinol self-expanding everolimus-eluting stent implantation for peripheral arterial occlusive disease

BackgroundA novel self-expanding drug-eluting stent was designed to slowly release everolimus to prevent restenosis following peripheral arterial intervention. The purpose of the first-in-human Superficial Femoral Artery Treatment with Drug-Eluting Stents (STRIDES) trial was to evaluate the safety and efficacy of this device for the treatment of symptomatic superficial femoral and proximal popliteal arterial occlusive disease.Methods and ResultsOne hundred four patients were enrolled at 11 European investigative centers in a prospective, nonrandomized, single-arm trial. The patients had severe symptomatic vascular disease, including a significant proportion of patients with critical limb ischemia (17%), diabetes (39%), and single-vessel outflow (26%). The mean lesion length was 9.0 ± 4.3 cm. Ninety-nine percent of patients were available for 12-month follow-up, including duplex imaging in 90% and arteriography in 83%. Clinical improvement, defined as a sustained decrease in Rutherford-Becker clinical category, was achieved in 80% of patients. Primary patency (freedom from ≥50% in-stent restenosis) was 94 ± 2.3% and 68 ± 4.6% at 6 and 12 months, respectively. Plain radiographic examination of 122 implanted devices at 12 months revealed no evidence for stent fracture.ConclusionsThe everolimus-eluting self-expanding nitinol stent can be successfully implanted in patients with severe peripheral arterial disease with favorable outcomes and clinical improvements observed in the majority of patients

Optically induced dynamic nuclear spin polarisation in diamond

The sensitivity of Magnetic Resonance Imaging (MRI) depends strongly on nuclear spin polarisation and, motivated by this observation, dynamical nuclear spin polarisation has recently been applied to enhance MRI protocols (Kurhanewicz, J., et al., Neoplasia 13, 81 (2011)). Nuclear spins associated with the 13 C carbon isotope (nuclear spin I = 1/2) in diamond possess uniquely long spin lattice relaxation times (Reynhardt, E.C. and G.L. High, Prog. in Nuc. Mag. Res. Sp. 38, 37 (2011)) If they are present in diamond nanocrystals, especially when strongly polarised, they form a promising contrast agent for MRI. Current schemes for achieving nuclear polarisation, however, require cryogenic temperatures. Here we demonstrate an efficient scheme that realises optically induced 13 C nuclear spin hyperpolarisation in diamond at room temperature and low ambient magnetic field. Optical pumping of a Nitrogen-Vacancy (NV) centre creates a continuously renewable electron spin polarisation which can be transferred to surrounding 13 C nuclear spins. Importantly for future applications we also realise polarisation protocols that are robust against an unknown misalignment between magnetic field and crystal axis.Comment: This is the revision submitted to NJ

Quality of life at the end of life

<p>Abstract</p> <p>Background</p> <p>Little is known about self-perceived quality of life (QOL) near the end of life, because such information is difficult to collect and to interpret. Here, we describe QOL in the weeks near death and determine correlates of QOL over time, with emphasis on accounting for death and missing data.</p> <p>Methods</p> <p>Data on QOL were collected approximately every week in an ongoing randomized trial involving persons at the end of life. We used these data to describe QOL in the 52 weeks after enrollment in the trial (prospective analysis, N = 115), and also in the 10 weeks just prior to death (retrospective analysis, N = 83). The analysis consisted of graphs and regressions that accounted explicitly for death and imputed missing data.</p> <p>Results</p> <p>QOL was better than expected until the final 3 weeks of life, when a terminal drop was observed. Gender, race, education, cancer, and baseline health status were not significantly related to the number of “weeks of good-quality life” (WQL) during the study period. Persons younger than 60 had significantly higher WQL than older persons in the prospective analysis, but significantly lower WQL in the retrospective analysis. The retrospective results were somewhat sensitive to the imputation model.</p> <p>Conclusion</p> <p>In this exploratory study, QOL was better than expected in persons at the end of life, but special interventions may be needed for persons approaching a premature death, and also for the last 3 weeks of life. Our descriptions of the trajectory of QOL at the end of life may help other investigators to plan and analyze future studies of QOL. Methodology for dealing with death and the high amount of missing data in longitudinal studies at the end of life needs further investigation.</p

Do 'good values' lead to 'good' health-behaviours? Longitudinal associations between young people's values and later substance-use

&lt;p&gt;Background: Past studies have linked certain values (traditional vs. individualistic) with adolescent substance-use. The aims of this study are to replicate cross-sectional research linking values and adolescent substance-use and to determine if such values predict future substance-use.&lt;/p&gt; &lt;p&gt;Methods: A longitudinal school-based survey of 2196 young people (age 15) followed up in early adulthood (age 18/19). Participants provided data about their beliefs and values at age 15, and their substance-use (smoking, alcohol and drug-use) at ages 15 and 18/19. In addition data were collected about their social background (gender, risk-taking, deprivation, religion, etc).&lt;/p&gt; &lt;p&gt;Results: Cross-sectionally, young people with anti-authority values were more likely to use various substances, e.g. 17-67% more likely to regularly smoke (daily), drink (most days), or use drugs (weekly) for each SD above typical levels. Adjusting for social background, associations were not substantially attenuated. However in the prospective analysis, adjusting for both background and substance-use at age 15, only two (anti-authoritarian and work ethic) values were (marginally) associated with substance-use at age 18/19.&lt;/p&gt; &lt;p&gt;Conclusions: While we replicated results found in prior cross-sectional studies, evidence from this study does not support the argument that holding certain 'pro-social' or 'good' values substantively protects against later substance-use and challenges the likely effectiveness of values-based interventions in relation to later substance-use.&lt;/p&gt

Chronic Pain in a Couples Context: A Review and Integration of Theoretical Models and Empirical Evidence

Researchers have become increasingly interested in the social context of chronic pain conditions. The purpose of this article is to provide an integrated review of the evidence linking marital functioning with chronic pain outcomes including pain severity, physical disability, pain behaviors, and psychological distress. We first present an overview of existing models that identify an association between marital functioning and pain variables. We then review the empirical evidence for a relationship between pain variables and several marital functioning variables including marital satisfaction, spousal support, spouse responses to pain, and marital interaction. On the basis of the evidence, we present a working model of marital and pain variables, identify gaps in the literature, and offer recommendations for research and clinical work