356 research outputs found

    Usefulness of 3D-PISA as compared to guideline endorsed parameters for mitral regurgitation quantification.

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    This study was intended to evaluate the diagnostic value of three dimensional proximal isovelocity surface area (3D PISA) derived effective regurgitant orifice area (EROA) and the accuracy of automatic 3D PISA detection in a population resembling clinical practice. Quantification of mitral regurgitation (MR) remains challenging and 3D PISA EROA is a novel diagnostic tool with promising results. However its' usefulness compared to guideline endorsed parameters has not been shown. In 93 consecutive patients examined in routine practice conventional parameters and 3D-datasets for offline 3D PISA evaluation were recorded. EROA was determined from the largest (peak) PISA and also averaged over systole for meanEROA. Results of 3D PISA calculation were compared with a combination of expert grading by two examiners and two scores for MR grading. In receiver operator characteristic-analysis the meanEROA as determined by 3D PISA had the best diagnostic value (AUC = 0.907 CI 0.832-0.983) as compared to peakEROA (AUC 0.840 CI 0.739-0.941), vena contracta width (AUC 0.831 CI 0.745-0.918) and 2D PISA (AUC 0.747 CI 0.644-0.850). A meanEROA of 0.15 cm2 had a sensitivity of 88.2 % and a specificity of 81.4 % for distinguishing severe from non-severe MR. Semiautomatic 3D PISA detection correlated very well with manually corrected values (r = 0.955). Semiautomatic 3D PISA measurement is feasible in a clinical population and has better diagnostic value compared to 2D PISA. Calculation of mean EROA throughout systole further improves diagnostic value compared to conventional parameters

    Aspirin inhibits the acute venodilator response to furosemide in patients with chronic heart failure

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    OBJECTIVES: We sought to determine the effect of aspirin on the venodilator effect of furosemide in patients with chronic heart failure (CHF) BACKGROUND: Furosemide has an acute venodilator effect preceding its diuretic action, which is blocked by nonsteroidal anti-inflammatory drugs. The ability of therapeutic doses of aspirin to block this effect of furosemide in patients with CHF has not been studied. For comparison, the venodilator response to nitroglycerin (NTG) was also studied. METHODS: Eleven patients with CHF were randomized to receive placebo, aspirin at 75 mg/day or aspirin at 300 mg/day for 14 days in a double-blind, crossover study. The effect of these pretreatments on the change in forearm venous capacitance (FVC) after 20 mg of intravenous furosemide was measured over 20 min by using venous occlusion plethysmography. In a second study, the effect of 400 μg of sublingual NTG on FVC was documented in 11 similar patients (nine participated in the first study). RESULTS: Mean arterial pressure, heart rate and forearm blood flow did not change in response to furosemide. After placebo pretreatment, furosemide caused an increase in FVC of 2.2% (95% confidence interval [CI] −0.9% to 5.2%; mean response over 20 min). By comparison, FVC fell by −1.1% (95% CI −4.2% to 1.9%) after pretreatment with aspirin at 75 mg/day, and by −3.7% (95% CI −6.8% to −0.7%) after aspirin at 300 mg/day (p = 0.020). In the second study, NTG increased FVC by 2.1% (95% CI −1.6% to 5.8%) (p = 0.95 vs. furosemide). CONCLUSIONS: In patients with CHF, venodilation occurs within minutes of the administration of intravenous dose of furosemide. Our observation that aspirin inhibits this effect further questions the use of aspirin in patients with CHF

    Mitochondrial oxidative stress and nitrate tolerance – comparison of nitroglycerin and pentaerithrityl tetranitrate in Mn-SOD(+/- )mice

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    BACKGROUND: Chronic therapy with nitroglycerin (GTN) results in a rapid development of nitrate tolerance which is associated with an increased production of reactive oxygen species (ROS). According to recent studies, mitochondrial ROS formation and oxidative inactivation of the organic nitrate bioactivating enzyme mitochondrial aldehyde dehydrogenase (ALDH-2) play an important role for the development of nitrate and cross-tolerance. METHODS: Tolerance was induced by infusion of wild type (WT) and heterozygous manganese superoxide dismutase mice (Mn-SOD(+/-)) with ethanolic solution of GTN (12.5 μg/min/kg for 4 d). For comparison, the tolerance-free pentaerithrityl tetranitrate (PETN, 17.5 μg/min/kg for 4 d) was infused in DMSO. Vascular reactivity was measured by isometric tension studies of isolated aortic rings. ROS formation and aldehyde dehydrogenase (ALDH-2) activity was measured in isolated heart mitochondria. RESULTS: Chronic GTN infusion lead to impaired vascular responses to GTN and acetylcholine (ACh), increased the ROS formation in mitochondria and decreased ALDH-2 activity in Mn-SOD(+/- )mice. In contrast, PETN infusion did not increase mitochondrial ROS formation, did not decrease ALDH-2 activity and accordingly did not lead to tolerance and cross-tolerance in Mn-SOD(+/- )mice. PETN but not GTN increased heme oxygenase-1 mRNA in EA.hy 926 cells and bilirubin efficiently scavenged GTN-derived ROS. CONCLUSION: Chronic GTN infusion stimulates mitochondrial ROS production which is an important mechanism leading to tolerance and cross-tolerance. The tetranitrate PETN is devoid of mitochondrial oxidative stress induction and according to the present animal study as well as numerous previous clinical studies can be used without limitations due to tolerance and cross-tolerance

    Jake Wells Enterprises and the Development of Urban Entertainments in the South, 1890-1925

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    This dissertation explores the development of commercial entertainments and film exhibition in the urban South around the turn of the last century through the growth and decline of Jake Wells Enterprises. A former professional baseball player, Wells invested in a wide variety of public amusements, with the core of his early business centered on establishing and organizing a string of vaudeville, popularly priced, and legitimate theaters throughout the largest cities in the region, a network he later transitioned to showing exclusively motion pictures. A thorough analysis of period newspapers, trade journals, and some business records covering Wells’ career provides much-needed evidence for film and cultural historians wishing to understand the genesis and evolution of public amusements in the region, and its negotiation of traditional social and cultural institutions. In the 1890s, Wells played and managed several professional baseball teams in the South. The sport educated players and spectators alike to both the values and creed of New South progress, and to rising tensions confronting the intersection of modern and traditional forms of culture. Using his experiences and contacts gained in baseball, Wells helped foster a culture of entrepreneurship and innovation required for the progress of media industries in the region, establishing social networks of knowledge and improving distribution flows of entertainment. The dissertation explores how race and the genteel emerged as regional characteristics most influential to the success of this conversion in many urban areas. Protestants and evangelical culture served as the bulkhead supporting opposition to new amusements. Wells’ expansion plans and violations of Sabbath day laws evoked a “spatial” battle between commercialism and religion where political, social, and cultural power drawn from place and identity were challenged and reconfigured. Another chapter explores the exhibition and reception of early Civil War films in the region. Wells and other exhibitors were influential in their production and circulation nationwide, and positioned cinema as an alternative shrine to commemorate the Lost Cause in many communities. The last chapter shows how Wells failed to meet local demands and consumer desires in competition with the rise of national chain theaters and Hollywood’s vertical integration

    The Choice of the Filtering Method in Microarrays Affects the Inference Regarding Dosage Compensation of the Active X-Chromosome

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    The hypothesis of dosage compensation of genes of the X chromosome, supported by previous microarray studies, was recently challenged by RNA-sequencing data. It was suggested that microarray studies were biased toward an over-estimation of X-linked expression levels as a consequence of the filtering of genes below the detection threshold of microarrays.To investigate this hypothesis, we used microarray expression data from circulating monocytes in 1,467 individuals. In total, 25,349 and 1,156 probes were unambiguously assigned to autosomes and the X chromosome, respectively. Globally, there was a clear shift of X-linked expressions toward lower levels than autosomes. We compared the ratio of expression levels of X-linked to autosomal transcripts (X∶AA) using two different filtering methods: 1. gene expressions were filtered out using a detection threshold irrespective of gene chromosomal location (the standard method in microarrays); 2. equal proportions of genes were filtered out separately on the X and on autosomes. For a wide range of filtering proportions, the X∶AA ratio estimated with the first method was not significantly different from 1, the value expected if dosage compensation was achieved, whereas it was significantly lower than 1 with the second method, leading to the rejection of the hypothesis of dosage compensation. We further showed in simulated data that the choice of the most appropriate method was dependent on biological assumptions regarding the proportion of actively expressed genes on the X chromosome comparative to the autosomes and the extent of dosage compensation.This study shows that the method used for filtering out lowly expressed genes in microarrays may have a major impact according to the hypothesis investigated. The hypothesis of dosage compensation of X-linked genes cannot be firmly accepted or rejected using microarray-based data

    Genomic mapping of 5-hydroxymethylcytosine in the human brain

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    Methylation at the 5-position of cytosine is a well-studied epigenetic pathway. In addition to 5-methylcytosine (5mC), substantial amounts of 5-hydroxymethylcytosine (5hmC) also referred to as the sixth DNA base have been detected in certain tissues, most notably the brain. However, the genomic distribution of this cytosine modification is unknown. Here, we have used an immunoprecipitation technique (5hmC-IP) to examine the occurrence of 5hmC in DNA from human brain frontal lobe tissue. The distribution of 5hmC was compared to that of 5mC. We show that 5hmC is more selectively targeted to genes than is 5mC. 5hmC is particularly enriched at promoters and in intragenic regions (gene bodies) but is largely absent from non-gene regions. 5hmC peaks at transcription start sites did not correlate with gene expression levels for promoters with intermediate or high CpG content. However, the presence of 5hmC in gene bodies was more positively correlated with gene expression levels than was the presence of 5mC. Promoters of testis-specific genes showed strong 5mC peaks in brain DNA but were almost completely devoid of 5hmC. Our data provide an overview of the genomic distribution of 5hmC in human brain and will set the stage for further functional characterization of this novel DNA modification

    Restricted Application of Insecticides: A Promising Tsetse Control Technique, but What Do the Farmers Think of It?

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    Restricted application of insecticides to cattle is a cheap and safe farmer-based method to control tsetse and the diseases they transmit, i.e. human and animal African trypanosomoses. The efficiency of this new control method has been demonstrated earlier but no data is available on its perception and adoption intensity by farmers. We studied these two features in Burkina Faso, where the method has diffused thanks to two development projects. The study allowed identifying three groups of farmers with various adoption intensities, of which one was modern and two traditional. The economic benefit and the farmers' knowledge of the epidemiological system appeared to have a low impact on the early adoption process whereas some modern practices, as well as social factors appeared critical. The quality of technical support provided to the farmers had also a great influence on the adoption rate. The study highlighted individual variations in risk perceptions and benefits, as well as the prominent role of the socio-technical network of cattle farmers. The results of the study are discussed to highlight the factors that should be taken into consideration, to move discoveries from bench to field for an improved control of trypanosomoses vectors

    The Defensive Role of Volatile Emission and Extrafloral Nectar Secretion for Lima Bean in Nature

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    Lima bean (Phaseolus lunatus) features two indirect anti-herbivore defenses—emission of volatile organic compounds (VOCs) and secretion of extrafloral nectar (EFN)—which are both inducible upon herbivore damage. In a previous field study, Lima bean benefited from the simultaneous induction of the two defenses, yet it remained unclear whether both had contributed to plant protection. Our experimental approach aimed at studying the defensive role of both indirect defenses simultaneously. Tendrils were sprayed with jasmonic acid (JA) to induce both defenses, and performance was compared to that of others that were treated with a synthetic blend of either EFN or VOCs. Confirming earlier results, JA treatment and application of the VOC mixture induced EFN secretion in treated tendrils in quantitatively similar amounts. The composition of the applied synthetic blend of EFN was adjusted to match the concentration of EFN secreted from JA- and VOC-treated tendrils. Repeated application of either enhanced the performance of several fitness-relevant plant parameters such as growth rate and flower production. Tendrils treated with JA showed a similar trend, yet some fitness-related parameters responded less to this treatment. This suggests a minor importance of any putative JA-dependent direct defense traits or higher costs of JA-elicited responses as compared to VOCS and EFN, as otherwise JA-treated tendrils should have outperformed VOC- and EFN-treated tendrils. Moreover, the beneficial effect of applying synthetic EFN alone equaled or exceeded that of VOCs and JA. Ants were by far the dominant group among the arthropods that was attracted to JA-, VOC-, or EFN-treated tendrils. The results suggest that EFN plays a more important role as an indirect defense of lima bean than VOCs or any other JA-responsive trait

    Impact of aspirin on takotsubo syndrome: a propensity score-based analysis of the InterTAK Registry

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    Aims: The aim of the present study was to investigate the impact of aspirin on prognosis in takotsubo syndrome (TTS). Methods and results: Patients from the International Takotsubo (InterTAK) Registry were categorized into two groups based on aspirin prescription at discharge. A comparison of clinical outcomes between groups was performed using an adjusted analysis with propensity score (PS) stratification; results from the unadjusted analysis were also reported to note the effect of the PS adjustment. Major adverse cardiac and cerebrovascular events (MACCE: a composite of death, myocardial infarction, TTS recurrence, stroke or transient ischaemic attack) were assessed at 30-day and 5-year follow-up. A total of 1533 TTS patients with known status regarding aspirin prescription at discharge were included. According to the adjusted analysis based on PS stratification, aspirin was not associated with a lower hazard of MACCE at 30-day [hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.50\u20133.04, P = 0.64] or 5-year follow-up (HR 1.11, 95% CI 0.78\u20131.58, P = 0.58). These results were confirmed by sensitivity analyses performed with alternative PS-based methods, i.e. covariate adjustment and inverse probability of treatment weighting. Conclusion: In the present study, no association was found between aspirin use in TTS patients and a reduced risk of MACCE at 30-day and 5-year follow-up. These findings should be confirmed in adequately powered randomized controlled trials. ClinicalTrials.gov Identifier: NCT01947621
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