30 research outputs found

    Lung cancer risk in never-smokers: a population-based case-control study of epidemiologic risk factors

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    <p>Abstract</p> <p>Background</p> <p>We conducted a case-control study in the greater Toronto area to evaluate potential lung cancer risk factors including environmental tobacco smoke (ETS) exposure, family history of cancer, indoor air pollution, workplace exposures and history of previous respiratory diseases with special consideration given to never smokers.</p> <p>Methods</p> <p>445 cases (35% of which were never smokers oversampled by design) between the ages of 20-84 were identified through four major tertiary care hospitals in metropolitan Toronto between 1997 and 2002 and were frequency matched on sex and ethnicity with 425 population controls and 523 hospital controls. Unconditional logistic regression models were used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the associations between exposures and lung cancer risk.</p> <p>Results</p> <p>Any previous exposure to occupational exposures (OR total population 1.6, 95% CI 1.4-2.1, OR never smokers 2.1, 95% CI 1.3-3.3), a previous diagnosis of emphysema in the total population (OR 4.8, 95% CI 2.0-11.1) or a first degree family member with a previous cancer diagnosis before age 50 among never smokers (OR 1.8, 95% CI 1.0-3.2) were associated with increased lung cancer risk.</p> <p>Conclusions</p> <p>Occupational exposures and family history of cancer with young onset were important risk factors among never smokers.</p

    Modeling CICR in rat ventricular myocytes: voltage clamp studies

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    <p>Abstract</p> <p>Background</p> <p>The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR) in cardiac myocytes, with voltage clamp (VC) studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect <it>Ca</it><sup>2+ </sup>loading of the sarcoplasmic reticulum (SR), and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR <it>Ca</it><sup>2+ </sup>release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic <it>Ca</it><sup>2+ </sup>concentration ([<it>Ca</it><sup>2+</sup>]<it><sub>myo</sub></it>).</p> <p>Methods</p> <p>The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU), in which resides the mechanistic basis of CICR). The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed <it>Ca</it><sup>2+ </sup>channels (trigger-channel and release-channel). It releases <it>Ca</it><sup>2+ </sup>flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[<it>Ca</it><sup>2+</sup>]<it><sub>myo</sub></it>.</p> <p>Results</p> <p>Our model reproduces measured VC data published by several laboratories, and generates graded <it>Ca</it><sup>2+ </sup>release at high <it>Ca</it><sup>2+ </sup>gain in a homeostatically-controlled environment where [<it>Ca</it><sup>2+</sup>]<it><sub>myo </sub></it>is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR <it>Ca</it><sup>2+ </sup>release, its activation by trigger <it>Ca</it><sup>2+</sup>, and its refractory characteristics mediated by the luminal SR <it>Ca</it><sup>2+ </sup>sensor. Proper functioning of the DCU, sodium-calcium exchangers and SERCA pump are important in achieving negative feedback control and hence <it>Ca</it><sup>2+ </sup>homeostasis.</p> <p>Conclusions</p> <p>We examine the role of the above <it>Ca</it><sup>2+ </sup>regulating mechanisms in handling various types of induced disturbances in <it>Ca</it><sup>2+ </sup>levels by quantifying cellular <it>Ca</it><sup>2+ </sup>balance. Our model provides biophysically-based explanations of phenomena associated with CICR generating useful and testable hypotheses.</p

    Hispanic health in the USA: a scoping review of the literature

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    Hispanics are the largest minority group in the USA. They contribute to the economy, cultural diversity, and health of the nation. Assessing their health status and health needs is key to inform health policy formulation and program implementation. To this end, we conducted a scoping review of the literature and national statistics on Hispanic health in the USA using a modified social-ecological framework that includes social determinants of health, health disparities, risk factors, and health services, as they shape the leading causes of morbidity and mortality. These social, environmental, and biological forces have modified the epidemiologic profile of Hispanics in the USA, with cancer being the leading cause of mortality, followed by cardiovascular diseases and unintentional injuries. Implementation of the Affordable Care Act has resulted in improved access to health services for Hispanics, but challenges remain due to limited cultural sensitivity, health literacy, and a shortage of Hispanic health care providers. Acculturation barriers and underinsured or uninsured status remain as major obstacles to health care access. Advantageous health outcomes from the “Hispanic Mortality Paradox” and the “Latina Birth Outcomes Paradox” persist, but health gains may be offset in the future by increasing rates of obesity and diabetes. Recommendations focus on the adoption of the Health in All Policies framework, expanding access to health care, developing cultural sensitivity in the health care workforce, and generating and disseminating research findings on Hispanic health

    Improving Carob Flour Performance for Making Gluten-Free Breads by Particle Size Fractionation and Jet Milling

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    Many different raw materials have been proposed for producing nutritious gluten-free breads, but rarely, there is a parallel analysis of the effect of physical treatment on those ingredients. The aim of this study was to incorporate carob flour fractions of varying particle size on rice gluten-free breads prepared with carob/rice (15:85) flour blends. Carob flour particle size was controlled by fractionation or jet milling application. Quality features of gluten-free breads containing carob flour and commercially available gluten-free breads were compared. Carob flour addition led to breads with improved colour parameters, crumb structure, retarded firming and lower moisture loss compared to rice bread. Further improvement in specific volume, crumb hardness, protein and ash content and estimated glycaemic index (eGI) could be obtained by a careful selection of the particle size distribution of the carob flour. Carob breads prepared either with the coarsest or the finest fraction prepared using jet milling led to end products with the highest specific volume (≈2.2 g/cm3) and the lowest crumb hardness (≈5.5 N), although they had lower specific volume and harder crumbs than breads from commercial blends (≈3–4 g/cm3, 0.6–3.8 N). Nevertheless, rice-based bread made with the finest carob flour was superior considering its slower firming, protein content and lower eGI. The incorporation of carob flour obtained by jet milling in rice-based gluten-free breads led to end products with quality characteristics and sensory acceptance resembling commercial breads and high nutritional value.Financial support of the Spanish Ministry of Economy and Competitiveness (Project AGL2014-52928-C2-1-R) and the European Regional Development Fund (FEDER)Peer reviewe
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