On the mass‐to‐light ratios of fossil groups. Are they simply dark clusters?

Defined as X‐ray bright galaxy groups with large differences between the luminosities of their brightest and second brightest galaxies, ‘fossil groups’ are believed to be some of the oldest galaxy systems in the Universe. They have therefore been the subject of much recent research. In this work we present a study of 10 fossil group candidates with an average of 33 spectroscopically confirmed members per group, making this the deepest study of its type to date. We also use these data to perform an analysis of the luminosity function of our sample of fossil groups. We confirm the high masses previously reported for many of fossil systems, finding values more similar to those of clusters than of groups. We also confirm the high dynamical mass‐to‐light ratios reported in many previous studies. While our results are consistent with previous studies in many ways, our interpretation is not. This is because we show that, while the luminosities of the bright central galaxies (BCGs) in these systems are consistent with their high dynamical masses, their richnesses (total number of galaxies above some canonical value) are extremely low. This leads us to suggest a new interpretation of fossil systems in which the large differences between the luminosities of their brightest and second brightest galaxies are simply the result of the high BCG luminosities and low richnesses, while the high masses and low richnesses also explain the high mass‐to‐light ratios. Our results therefore suggest that fossil systems can be characterized as cluster‐like in their masses and BCG luminosities, but possessing the richnesses and optical luminosities of relatively poor groups. These findings are not predicted by any of the current models for the formation of fossil groups. Therefore, if this picture is confirmed, current ideas about the formation and evolution of fossil systems will need to be reformulated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89559/1/j.1365-2966.2011.19625.x.pd

Repeated Measurements of Cardiac Biomarkers in Atrial Fibrillation and Validation of the ABC Stroke Score Over Time

Background--Cardiac biomarkers are independent risk markers in atrial fibrillation, and the novel biomarker-based ABC stroke score (age, biomarkers, and clinical history of prior stroke) was recently shown to improve the prediction of stroke risk in patients with atrial fibrillation. Our aim was to investigate the short-term variability of the cardiac biomarkers and evaluate whether the ABC stroke risk score provides a stable short- term risk estimate. Methods and Results--According to the study protocol, samples were obtained at entry and also at 2 months in 4796 patients with atrial fibrillation followed for a median of 1.8 years in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. Cardiac troponin I, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide were measured with high-sensitivity immunoassays. Associations with outcomes were evaluated by Cox regression. C indices and calibration plots were used to evaluate the ABC stroke score at 2 months. The average changes in biomarker levels during 2 months were small ( median change cardiac troponin T +2.8%, troponin I +2.0%, and N-terminal pro-B-type natriuretic peptide +13.5%) and within-subject correlation was high ( all >= 0.82). Repeated measurement of cardiac biomarkers provided some incremental prognostic value for mortality but not for stroke when combined with clinical risk factors and baseline levels of the biomarkers. Based on 8702 person-years of follow-up and 96 stroke/systemic embolic events, the ABC stroke score at 2 months achieved a similar C index of 0.70 (95% CI, 0.65-0.76) as compared with 0.70 (95% CI, 0.65-0.75) at baseline. The ABC stroke score remained well calibrated using predefined risk classes. Conclusions--In patients with stable atrial fibrillation, the variability of the cardiac biomarkers and the biomarker- based ABC stroke score during 2 months are small. The prognostic information by the ABC stroke score remains consistent and well calibrated with similar good predictive performance if patients are retested after 2 months. Clinical Trial Registration --URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984.Peer reviewe

Pandemonium During the Pandemic: What is the Role of Health and Science Professionals?

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A multifaceted intervention to narrow the evidence-based gap in the treatment of acute coronary syndromes: Rationale and design of the Brazilian Intervention to Increase Evidence Usage in Acute Coronary Syndromes (BRIDGE-ACS) cluster-randomized trial

Translating evidence into clinical practice in the management of acute coronary syndromes (ACS) is challenging. Few ACS quality improvement interventions have been rigorously evaluated to determine their impact on patient care and clinical outcomes. We designed a pragmatic, 2-arm, cluster-randomized trial involving 34 clusters (Brazilian public hospitals). Clusters were randomized to receive a multifaceted quality improvement intervention (experimental group) or routine practice (control group). the 6-month educational intervention included reminders, care algorithms, a case manager, and distribution of educational materials to health care providers. the primary end point was a composite of evidence-based post-ACS therapies within 24 hours of admission, with the secondary measure of major cardiovascular clinical events (death, nonfatal myocardial infarction, nonfatal cardiac arrest, and nonfatal stroke). Prescription of evidence-based therapies at hospital discharge were also evaluated as part of the secondary outcomes. All analyses were performed by the intention-to-treat principle and took the cluster design into account using individual-level regression modeling (generalized estimating equations). If proven effective, this multifaceted intervention would have wide use as a means of promoting optimal use of evidence-based interventions for the management of ACS. (Am Heart J 2012;163:323-329.e1.)Brazilian Ministry of HealthHospital do Coracao (HCor)Res Inst HCor Hosp Coracao, São Paulo, BrazilDuke Univ, Med Ctr, Duke Clin Res Inst, Durham, NC USAUniversidade Federal de São Paulo, Brazilian Clin Res Inst, Paulista Sch Med, São Paulo, BrazilUniversidade Federal de São Paulo, Brazilian Clin Res Inst, Paulista Sch Med, São Paulo, BrazilWeb of Scienc

Highlights from the III International Symposium of Thrombosis and Anticoagulation (ISTA), October 14-16, 2010, São Paulo, Brazil

To discuss and share knowledge around advances in the care of patients with thrombotic disorders, the Third International Symposium of Thrombosis and Anticoagulation was held in So Paulo, Brazil, from October 14-16, 2010. This scientific program was developed by clinicians for clinicians, and was promoted by four major clinical research institutes: the Brazilian Clinical Research Institute, the Duke Clinical Research Institute of the Duke University School of Medicine, the Canadian VIGOUR Centre, and the Uppsala Clinical Research Center. Comprising 3 days of academic presentations and open discussion, the symposium had as its primary goal to educate, motivate, and inspire internists, cardiologists, hematologists, and other physicians by convening national and international visionaries, thought-leaders, and dedicated clinician-scientists. This paper summarizes the symposium proceedings.AlexiumAstraZenecaBoehringer IngelheimBristol-Myers SquibbCSL BehringDaiichi SankyoLeo PharmaSanofi-aventisDuke Univ, Med Ctr, Duke Clin Res Inst, Durham, NC 27705 USAUniversidade Federal de São Paulo, Paulista Sch Med, São Paulo, BrazilUniv Alberta, Edmonton, AB, CanadaNatl Univ, Ctr Heart, Singapore, SingaporeMcMaster Univ, Hamilton, ON, CanadaBoston Univ, Boston, MA 02215 USAUppsala Univ, Uppsala, SwedenUniv Montreal, Montreal Heart Inst, Montreal, PQ, CanadaKatholieke Univ Leuven Hosp, Louvain, BelgiumGreen Lane Cardiovasc Res Unit, Auckland, New ZealandUniv São Paulo, Sch Med, São Paulo, BrazilFed Univ Hlth Sci Porto Alegre, Porto Alegre, RS, BrazilUniv Estadual Campinas, São Paulo, BrazilUniv New Mexico, Hlth Sci Ctr, Albuquerque, NM 87131 USAUniversidade Federal de São Paulo, Paulista Sch Med, São Paulo, BrazilWeb of Scienc

Direct oral anticoagulants for stroke prevention in patients with device-detected atrial fibrillation: assessing net clinical benefit

Subclinical, device-detected atrial fibrillation (AF) is frequently recorded by pacemakers and other implanted cardiac rhythm devices. Patients with device-detected AF have an elevated risk of stroke, but a lower risk of stroke than similar patients with clinical AF captured with surface electrocardiogram. Two randomized clinical trials (NOAH-AFNET 6 and ARTESiA) have tested a direct oral anticoagulant (DOAC) against aspirin or placebo. A study-level meta-analysis of the two trials found that treatment with a DOAC resulted in a 32\2\ the results of the two trials were consistent. The annualized rate of stroke in the control arms was ∼1\detected AF. Strokes in ARTESiA were frequently fatal or disabling and bleeds were rarely lethal. The higher absolute rates of major bleeding compared with ischaemic stroke while on treatment with a DOAC in the two trials are consistent with the ratio of bleeds to strokes seen in the pivotal DOAC vs. warfarin trials in patients with clinical AF. Prior research has concluded that patients place a higher emphasis on stroke prevention than on bleeding. Further research is needed to identify the characteristics that will help identify patients with device-detected AF who will receive the greatest benefit from DOAC treatment

Endothelial function in patients with slow coronary flow and normal coronary angiography

Submitted by Cristina Damasceno ([email protected]) on 2012-12-12T00:09:10Z No. of bitstreams: 1 Endothelial function in patients with slow coronary flow and normal coronary angiography.pdf: 98888 bytes, checksum: aed454abc693219249d14f5e19b135af (MD5)Approved for entry into archive by Michele Fernanda([email protected]) on 2013-03-22T13:35:49Z (GMT) No. of bitstreams: 1 Endothelial function in patients with slow coronary flow and normal coronary angiography.pdf: 98888 bytes, checksum: aed454abc693219249d14f5e19b135af (MD5)Made available in DSpace on 2013-03-22T13:35:49Z (GMT). No. of bitstreams: 1 Endothelial function in patients with slow coronary flow and normal coronary angiography.pdf: 98888 bytes, checksum: aed454abc693219249d14f5e19b135af (MD5) Previous issue date: 201

Do Omega-3 fatty acids prevent atrial fibrillation after open heart surgery? A meta-analysis of randomized controlled trials

OBJECTIVES: N-3 polyunsaturated fatty acids have been proposed as a novel treatment for preventing postoperative atrial fibrillation due to their potential anti-inflammatory and anti-arrhythmic effects. However, randomized studies have yielded conflicting results. The objective of this study is to review randomized trials of N-3 polyunsaturated fatty acid use for postoperative atrial fibrillation. METHODS: Using the CENTRAL, PUBMED, EMBASE, and LILACS databases, a literature search was conducted to identify all of the studies in human subjects that reported the effects of N-3 polyunsaturated fatty acids on the prevention of postoperative atrial fibrillation in cardiac surgery patients. The final search was performed on January 30, 2011. There was no language restriction, and the search strategy only involved terms for N-3 polyunsaturated fatty acids (or fish oil), atrial fibrillation, and cardiac surgery. To be included, the studies had to be randomized (open or blinded), and the enrolled patients had to be >18 years of age. RESULTS: Four randomized studies (three double-blind, one open-label) that enrolled 538 patients were identified. The patients were predominantly male, the mean age was 62.3 years, and most of the patients exhibited a normal left atrial size and ejection fraction. N-3 polyunsaturated fatty acid use was not associated with a reduction in postoperative atrial fibrillation. Similar results were observed when the open-label study was excluded. CONCLUSIONS: There is insufficient evidence to suggest that treatment with N-3 polyunsaturated fatty acids reduces postoperative atrial fibrillation. Therefore, their routine use in patients undergoing cardiac surgery is not recommended

Pandemônio Durante a Pandemia: Qual o Papel dos Profissionais da Saúde e a Ciência?

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Analytical methods in photoelectrochemical treatment of phenol

The aim of the study was to propose a treatment of simulated wastewater containing phenol by photocatalytic and photolytic processes and analyze the toxicity of these phenolic solutions. Two treatment systems were performed with UV radiation, solid electrodes and electric potential. In the first system (S1) phenol concentration was determined by UV direct spectrophotometry (269 nm) and in the second (S2) by direct photometric method (4-aminoantipyrine). Toxicological tests were carried out using two microorganisms: Escherichia coli and Saccharomyces cerevisiae. S1 results showed that erroneous conclusions can be drawn by absorbance values increase at phenol peak. Nevertheless, direct photometric method was able to identify phenol reduction in S2 and the proposed treatments degraded phenol in solution. Also, in treatment using high energy ultraviolet radiation (UVC), the phenol degradation was mainly due to the photolytic process.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação para o Desenvolvimento da UNESP (FUNDUNESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Estadual Paulista, Dept Bioquim & Microbiol, Inst Biociencias, Rio Claro, SP, BrazilUniv Estadual Paulista, Dept Bioquim & Microbiol, Inst Biociencias, Rio Claro, SP, BrazilUNESP/Rio Claro: PRH-0