260 research outputs found

    Is Acute High-Dose Secondhand Smoke Exposure Always Harmful to Microvascular Function in Healthy Adults?

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    Prev Cardiol.Long-term exposure to secondhand smoke (SHS) is associated with impaired vascular function. The authors investigated the vascular and blood pressure (BP) reactions to acute SHS exposure. Twenty-five healthy nonsmoking adults underwent a 1-hour exposure to SHS (mean fine particulate matter <2.5 μm level=315±116 μg/m 3 ). Microvascular endothelial-dependent vasodilatation (EDV) (EndoPAT, Itamar Medical, Caesarea, Israel) and aortic hemodynamics/compliance (SphygmoCor, AtCor Medical, West Ryde, Australia) were measured before and after the SHS exposure with BP measured every 15 minutes during and for a 24-hour period before and after the exposure. SHS exposure did not change EDV, aortic hemodynamics, arterial compliance, or 24-hour BP. However, diastolic BP significantly increased during the SHS exposure period by 3.4±5.6 mm Hg. Our brief SHS exposure did not impair microvascular endothelial function or arterial compliance in healthy nonsmoking adults, but brachial diastolic BP increased.Prev Cardiol. 2010;13:175–179. © 2010 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79199/1/j.1751-7141.2010.00074.x.pd

    Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-beta and Runx2 in bone is required for hearing

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    Publisher version: http://www.nature.com/embor/journal/v11/n10/full/embor2010135.htmlDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEPhysical cues, such as extracellular matrix stiffness, direct cell differentiation and support tissue-specific function. Perturbation of these cues underlies diverse pathologies, including osteoarthritis, cardiovascular disease and cancer. However, the molecular mechanisms that establish tissue-specific material properties and link them to healthy tissue function are unknown. We show that Runx2, a key lineage-specific transcription factor, regulates the material properties of bone matrix through the same transforming growth factor-beta (TGFbeta)-responsive pathway that controls osteoblast differentiation. Deregulated TGFbeta or Runx2 function compromises the distinctly hard cochlear bone matrix and causes hearing loss, as seen in human cleidocranial dysplasia. In Runx2(+/-) mice, inhibition of TGFbeta signalling rescues both the material properties of the defective matrix, and hearing. This study elucidates the unknown cause of hearing loss in cleidocranial dysplasia, and demonstrates that a molecular pathway controlling cell differentiation also defines material properties of extracellular matrix. Furthermore, our results suggest that the careful regulation of these properties is essential for healthy tissue functio

    Added sugar intake and metabolic syndrome in US adolescents: cross-sectional analysis of the National Health and Nutrition Examination Survey 2005–2012

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    ObjectiveTo examine the association between added sugar intake and metabolic syndrome among adolescents.DesignDietary, serum biomarker, anthropometric and physical activity data from the US National Health and Nutrition Examination Survey cycles between 2005 and 2012 were analysed using multivariate logistic regression models. Added sugar intake in grams per day was estimated from two 24 h standardized dietary recalls and then separated into quintiles from lowest to highest consumption. Multivariate logistic regression analyses were adjusted for physical activity, age, BMI Z-score and energy intake, and their interactions with race were included.SettingNationally representative sample, USA.SubjectsUS adolescents aged 12-19 years (n 1623).ResultsAdded sugar was significantly associated with metabolic syndrome. The adjusted prevalence odds ratios for having metabolic syndrome comparing adolescents in the third, fourth and fifth quintiles v. those in the lowest quintile of added sugar were 5·3 (95 % CI 1·4, 20·6), 9·9 (95 % CI 1·9, 50·9) and 8·7 (95 % CI 1·4, 54·9), respectively.ConclusionsOur findings suggest that higher added sugar intake, independent of total energy intake, physical activity or BMI Z-score, is associated with increased prevalence of metabolic syndrome in US adolescents. Further studies are needed to determine if reducing intake of added sugar may help US adolescents prevent or reverse metabolic syndrome

    Imaging Renal Urea Handling in Rats at Millimeter Resolution using Hyperpolarized Magnetic Resonance Relaxometry

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    \textit{In vivo} spin spin relaxation time (T2T_2) heterogeneity of hyperpolarized \textsuperscript{13}C urea in the rat kidney was investigated. Selective quenching of the vascular hyperpolarized \textsuperscript{13}C signal with a macromolecular relaxation agent revealed that a long-T2T_2 component of the \textsuperscript{13}C urea signal originated from the renal extravascular space, thus allowing the vascular and renal filtrate contrast agent pools of the \textsuperscript{13}C urea to be distinguished via multi-exponential analysis. The T2T_2 response to induced diuresis and antidiuresis was performed with two imaging agents: hyperpolarized \textsuperscript{13}C urea and a control agent hyperpolarized bis-1,1-(hydroxymethyl)-1-\textsuperscript{13}C-cyclopropane-2H8^2\textrm{H}_8. Large T2T_2 increases in the inner-medullar and papilla were observed with the former agent and not the latter during antidiuresis suggesting that T2T_2 relaxometry may be used to monitor the inner-medullary urea transporter (UT)-A1 and UT-A3 mediated urea concentrating process. Two high resolution imaging techniques - multiple echo time averaging and ultra-long echo time sub-2 mm3^3 resolution 3D imaging - were developed to exploit the particularly long relaxation times observed

    Long-Term Memory for the Terrorist Attack of September 11: Flashbulb Memories, Event Memories, and the Factors That Influence Their Retention

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    More than 3,000 individuals from 7 U.S. cities reported on their memories of learning of the terrorist attacks of September 11, as well as details about the attack, 1 week, 11 months, and/or 35 months after the assault. Some studies of flashbulb memories examining long-term retention show slowing in the rate of forgetting after a year, whereas others demonstrate accelerated forgetting. This article indicates that (a) the rate of forgetting for flashbulb memories and event memory (memory for details about the event itself) slows after a year, (b) the strong emotional reactions elicited by flashbulb events are remembered poorly, worse than nonemotional features such as where and from whom one learned of the attack, and (c) the content of flashbulb and event memories stabilizes after a year. The results are discussed in terms of community memory practices.James S. McDonnell FoundationNational Institutes of Health (U.S.) (grant R01- MH0066972

    The Critical Juncture Concept’s Evolving Capacity to Explain Policy Change

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    This article examines the evolution of our understanding of the critical junctures concept. The concept finds its origins in historical intuitionalism, being employed in the context of path dependence to account for sudden and jarring institutional or policy changes. We argue that the concept and the literature surrounding it—now incorporating ideas, discourse, and agency—have gradually become more comprehensive and nuanced as historical institutionalism was followed by ideational historical institutionalism and constructivist and discursive institutionalism. The prime position of contingency has been supplanted by the role of ideas and agency in explaining critical junctures and other instances of less than transformative change. Consequently, the concept is now capable of providing more comprehensive explanations for policy change
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