89 research outputs found

    Prevalence and significance of alterations in cardiac structure and function in patients with heart failure and a preserved ejection fraction

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    <p><b>Background:</b> The purpose of this study was to examine the prevalence of abnormalities in cardiac structure and function present in patients with heart failure and a preserved ejection fraction (HFPEF) and to determine whether these alterations in structure and function were associated with cardiovascular morbidity and mortality.</p> <p><b>Methods and Results:</b> The Irbesartan in HFPEF trial (I-PRESERVE) enrolled 4128 patients; echocardiographic determination of left ventricular (LV) volume, mass, left atrial (LA) size, systolic function, and diastolic function were made at baseline in 745 patients. The primary end point was death or protocol-specific cardiovascular hospitalization. A secondary end point was the composite of heart failure death or heart failure hospitalization. Associations between baseline structure and function and patient outcomes were examined using univariate and multivariable Cox proportional hazard analyses. In this substudy, LV hypertrophy or concentric remodeling was present in 59%, LA enlargement was present in 66%, and diastolic dysfunction was present in 69% of the patients. Multivariable analyses controlling for 7 clinical variables (including log N-terminal pro-B–type natriuretic peptide) indicated that increased LV mass, mass/volume ratio, and LA size were independently associated with an increased risk of both primary and heart failure events (all P<0.05).</p> <p><b>Conclusions:</b> Left ventricular hypertrophy or concentric remodeling, LA enlargement, and diastolic dysfunction were present in the majority of patients with HFPEF. Left ventricular mass and LA size were independently associated with an increased risk of morbidity and mortality. The presence of structural remodeling and diastolic dysfunction may be useful additions to diagnostic criteria and provide important prognostic insights in patients with HFPEF.</p&gt

    Sonic diaspora, vibrations and rhythm: thinking through the sounding of the Jamaican dancehall session

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    The propagation of vibrations may provide a better way of understanding diasporic spread than the conventional focus on the circulation of products (Hall 1980, Appadurai 1986, 1996, Gilroy 1993a, Brah 1996). Jamaican sound systems operate as a broadcast medium and a source of CDs, DVDs and other commercial products (Henriques 2007a). But the dancehall sound system session also propagates a broad spectrum of frequencies diffused through a range of media and activities - described as “sounding” (following Small’s 1998 concept of “musicking”). These include the material vibrations of the signature low-pitched auditory frequencies of Reggae as a bass culture (Johnson 1980), at the loudness of “sonic dominance” (Henriques 2003). Secondly a session propagates the corporeal vibrations of rituals, dance routines and bass-line “riddims” (Veal 2007). Thirdly it propagates the ethereal vibrations (Henriques 2007b), “vibes” or atmosphere of the sexually charged popular subculture by which the crowd (audience) appreciate each dancehall session as part of the Dancehall scene (Cooper 2004). The paper concludes that thinking though vibrating frequencies makes it easier to appreciate how audiences with no direct or inherited connection with a particular music genre can be energetically infected and affected - to form a sonic diaspora

    Manual asymmetries in the preparation and control of goal-directed movements

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    The primary purpose of this experiment was to determine if left hand reaction time advantages in manual aiming result from a right hemisphere attentional advantage or an early right hemisphere role in movement preparation. Right-handed participants were required to either make rapid goal-directed movements to small targets or simply lift their hand upon target illumination. The amount of advance information about the target for a particular trial was manipulated by precuing a subset of potential targets prior to the reaction time interval. When participants were required to make aiming movements to targets in left space, the left hand enjoyed a reaction advantage that was not present for aiming in right space: or simple finger lifts. This advantage was independent of the amount or type of advance information provided by the precue. This finding supports the movement planning hypothesis. With respect to movement execution, participants completed their aiming movements more quickly when aiming with their right hand, particularly in right space. This right hand advantage in right space was due to the time required to decelerate the movement and to make feedback-based adjustments late in the movement trajectory. (C) 2001 Academic Press

    Inhibition of ruminal bacteria involved in lactic acid metabolism by extracts from Australian plants

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    Ethanolic extracts, essential oils and plant secondary compounds from selected Australian plants were tested in vitro for their potential to selectively inhibit bacteria associated with lactic acid production in ruminants. A combination of agar dilution and microbroth dilution assays were used to determine the minimum inhibitory concentration (MIC) of the plant extracts against a panel of ruminal bacteria. Ethanolic extract from Eremophila glabra inhibited lactate producers and all other rumen bacteria at 1.260. mg/ml, except for the ruminal lactate fermenter Megasphaera elsdenii (MIC 10. mg/ml). Extracts from Acacia decurrens, A. saligna, Kennedia eximia and K. prorepens inhibited ruminal lactate producer Lactobacillus spp. only (MIC from 5 to 10. mg/ml). The MIC of essential oils ranged from 0.003 to 0.020. mg/ml, but the inhibitory effect was not specific to lactate producers. E. glabra was identified as the plant with the most favourable effect and purified compounds from this plant were investigated for further analysis. Seven serrulatane diterpenes were isolated by chromatography and tested against the major ruminal lactate producer Streptococcus bovis and a lactate fermenter M. elsdenii in a microbroth dilution assay. All but one of these inhibited S. bovis, with the MIC ranging from 0.320 to 1.080. mg/ml, with only one compound also inhibiting M. elsdenii (MIC 1.080. mg/ml). Selective inhibition of lactate producing bacteria in the rumen by some Australian plant extracts and their secondary compounds was identified and may lead to further research into the application of bioactive plants in the management of lactic acidosis in ruminants

    Assessment of long-term effects of irbesartan on heart failure with preserved ejection fraction as measured by the Minnesota living with heart failure questionnaire in the Irbesartan in Heart Failure with Preserved Systolic Function (I-PRESERVE) trial

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    Background: The Minnesota Living with Heart Failure Questionnaire (MLHFQ) was used in a large, multinational, randomized, placebo-controlled trial to measure adverse effects of heart failure with preserved ejection fraction (HF-PEF) on patients' lives and the effects of irbesartan. <p/>Methods and Results: Patients with symptomatic HF-PEF were randomly assigned to irbesartan (up to 300 mg daily) or placebo. The MLHFQ was administered at baseline (n=3605), month 6 (n=3137), month 14 (n=2904), and the end of study (median, 56 months, n=2205). Baseline MLHFQ scores of 43±21 indicated that HF-PEF had a substantial adverse effects. Estimated retest reliability was 0.80. Baseline MLHFQ scores were associated with other measures of the severity of heart failure including symptoms, signs of congestion, cardiac structure, and time to hospitalizations or deaths attributed to heart failure. Slight improvement in shortness of breath or fatigue was associated with significant improvement in MLHFQ scores (−5.9 and −5.0, P<0.0001). Compared with placebo, further improvement in MLHFQ scores was not observed with irbesartan after 6 months (mean adjusted difference, 0.4; 95% confidence interval, −0.8 to 1.7), 14 months (0.5; 95% confidence interval, −0.9 to 1.8), or the end of study (2.0; 95% confidence interval, −4.1 to 0.01). <p/>Conclusions: The MLHFQ scores are a reliable, valid, and sensitive measure of the adverse impact of HF-PEF on patients' lives. Irbesartan did not substantially improve MLHFQ scores during a long period of follow-up
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