1,721,011 research outputs found
Oxidative stress biomarkers as predictors of cardiovascular disease
Evidence for the role of oxidative stress in the pathogenesis of cardiovascular disease (CVD) is primarily based on experimental and observational human studies. The aim of this review is to examine the observational longitudinal studies that have investigated the relationship between oxidative stress biomarkers and CVD. Fifty-one studies were identified with twenty-six of these measuring oxidized (Ox)-LDL, fifteen assessing myeloperoxidase, seven using lipid peroxidation measures and three quantifying protein oxidation. Results of studies using Ox-LDL have been equivocal with sixteen of the twenty-six studies reporting that this measure is predictive of cardiovascular events. These inconsistent results are not explained by differences in the study populations (primary or secondary CVD) or the type of assay used (auto or monoclonal antibodies). Six of the seven lipid peroxidation, and two of three protein oxidation studies found associations. Twelve of fifteen studies assessing the role of myeloperoxidase reported it to be predictive of CVD. However, issues surrounding the specificity of myeloperoxidase as a marker of oxidative stress and the small number of research groups reporting these results, limit this finding. In summary, the ability of oxidative stress biomarkers to predict CVD has yet to be established. Furthermore, it is important to note that the methods used to assess oxidative stress in these studies are indirect, and the evidence that the various methods actually reflect oxidative stress in vivo is limited. (C) 2010 Elsevier Ireland Ltd. All rights reserved
Assessing HRQL among Chinese patients with coronary heart disease: Angina, myocardial infarction and heart failure
Objective: To perform a psychometric evaluation of the Myocardial Infarction Dimensional Assessment Scale (MIDAS) in Chinese patients with coronary heart disease. Design and setting: Patients with angina (n = 162), MI (n = 124) or heart failure (n = 95) were recruited from a regional university-affiliated hospital. The Chinese version of the MIDAS (C-MIDAS), the Hospital Anxiety and Depression Scale (HADS) and the Short-Form 36 Health Survey (SF-36) were administered to all patients at baseline and the C-MIDAS was also administered seven day (n = 92) and three months (n = 363) later. Results: The C-MIDAS conforms to the 7-factor structure as proposed in the original version. It is reliable with Cronbach's alphas from 0.73 to 0.94 and test-retest reliabilities from 0.76 to 0.92. Four of its subscales (physical activity, insecurity, emotional reaction and dependency) correlated significantly with the SF-36 and the HADS in each diagnostic group and had good discriminative properties in terms of gender, emotional disturbance and perceived health deterioration, with responsiveness supported by medium-high effect sizes (0.43-0.83) and standardize response means (0.46-0.82). The other three subscales measuring treatment-related impacts added little to the validity and responsiveness of the C-MIDAS. Conclusion: To render the C-MIDAS a core health-related quality of life measure for Chinese-speaking patients with coronary heart disease, further studies need to clarify the content adequacy and cultural relevancy of those subscales measuring treatment-related impact.</p
“Prehabilitation” prior to CABG surgery improves physical functioning and depression
Background: Many patients demonstrate psychological distress and reduced physical activity before coronary artery bypass graft surgery (CABG). Here we evaluated the addition of a brief, cognitive-behavioural intervention (the HeartOp Programme) to routine nurse counselling for people waiting for CABG surgery.
Methods: Randomised controlled trial comparing nurse counselling with the HeartOp programme to routine nurse counselling in 204 patients awaiting first time elective CABG. Primary outcome measures were: anxiety and length of hospital stay; secondary outcome measures were: depression, physical functioning, cardiac misconceptions and cost utility. Measures were collected prior to randomisation and after 8 weeks of their intervention prior to surgery, excepting length of hospital stay which was collected after discharge following surgery.
Results: 100 patients were randomised to intervention, 104 to control. At follow-up there were no differences in anxiety or length of hospital stay. There were significant differences in depression (difference=7.79, p=0.008, 95% CI=2.04–13.54), physical functioning (difference=0.82, p=0.001, 95%CI=0.34–1.3) and cardiac misconceptions (difference=2.56, pb0.001, 95%CI=1.64–3.48) in favour of the HeartOp Programme. The only difference to be maintained following surgery was in cardiac misconceptions. The HeartOp Programme was found to have an Incremental Cost Effectiveness Ratio (ICER) of £288.83 per Quality-Adjusted Life Year.
Conclusions: Nurse counselling with the HeartOp Programme reduces depression and cardiac misconceptions and improves physical functioning before bypass surgery significantly more than nurse counselling alone and meets the accepted criteria for cost efficacy.
© 2008 Elsevier Ireland Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effect of atorvastatin on cardiac remodelling and mortality in rats following hyperglycemia and myocardial infarction
Effect of HMGCoA Reductase Inhibitors on Cardiac Remodelling and Mortality in Rats. Following Hyperglycemia and Myocardial Infarction
Mapping the emergence of heart disease in a black, urban population in Africa: The Heart of Soweto Study
Background: There is increasing evidence that many populations in the developing world are in epidemiologic transition with the subsequent emergence of more affluent disease states. The Heart of Soweto Study will systematically investigate the emergence of heart disease (HD) in a large urban population in South Africa. Methods: Part of the conurbation of Johannesburg, South Africa, Soweto is a predominantly Black African community of I million individuals. During an initial two year period, all individuals presenting to the local Baragwanath Hospital (3500 beds) with any form of HD will be studied. Demographic and diagnostic coding data in those with pre-established HD will form an abbreviated clinical registry of > 12,000 prevalent cases. Similarly, socio-demographic, clinical and diagnostic data (e.g. echocardiography and ECG) in newly diagnosed patients will form a more detailed clinical registry of > 5000 incident cases. Sub-studies of the relationship between HIV status and H D and the optimal management of chronic heart failure will also be performed. Results: These data will provide a unique insight into the causes and consequences of a broad spectrum of HD-related conditions in a developing world community in epidemiologic transition. Initially documented Population rates, in addition to detailed examinations of the underlying risk factors and causes of HD-related morbidity/mortality will provide an important platform for future stages of the study: a community-based, population screening program and culturally specific primary and secondary programs of care. Conclusion: There is an urgent need to systematically track the emergence of HD in the developing world. Initially involving more than 15,000 individuals, the unique Heart of Soweto Study has the potential to provide a wealth of information in this regard. (c) 2006 Elsevier Ireland Ltd. All rights reserved
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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