1,720,957 research outputs found
Age related prolactin secretion in men after fentanyl anaesthesia
No full textThe aim of this study was to investigate the role of age in the hormonal response to opiate anaesthetic fentanyl. In 90 patients undergoing aortocoronary bypass, 59.69.2 years mean age, 35–81 age range, prolactin (PRL), thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), human growth hormone (HGH), insulin-like growth factor I (IGF I), glucagon and insulin were measured in venous blood samples drawn from fasting patients immediately before, at 8 h in the morning, and 60 min after the induction of anaesthesia with 30 g/kg intravenous fentanyl bolus, 30 min after a second 7 g/kg fentanyl bolus. Results showed a higher 60 min PRL peak in older, 65 years, in respect to younger, 50 years, patients (57.623.3 vs. 40.613.8 g/l, P0.005), with a significant upward trend with age across the entire age span (r=0.32; P0.002), while no difference by age was found for the basal concentrations. No differences were found between the respective basal and 60 min concentrations for the other hormones investigated. As expected, differences by age were found for FSH, higher in 65 and in 51–65-year-olds than in younger patients (for the basal values, respectively, P0.02 and P0.05); IGF I was lower in 65 in respect to50 (P0.02) and to 51–65-year-old patients (P0.05), with a significant negative correlation with age (r=−0.33; P0.005). The study shows an age related increase of PRL concentrations after fentanyl administration
The acute myocardial infarction in very elderly
No full textA total 325 patients were studied at admission for myocardial infarction, measuring plasma fibrinogen (FBG), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) and automatized hemocromocytometric parameters in order to contribute to explain the excess mortality reported in very elderly patients. It was found that age positively correlated with fibrinogen and LDH values and inversely with CPK, hemoglobin concentration and lymphocyte count. The unpaired comparison of the variables studied in age subgroups showed no differences between patients aged 65 or less than 65 years and patients aged 66-75 years. In patients aged over 75 years FBC, neutrophile count and LDH were significantly higher in respect to 65 or less and 66-75 years age subgroups and hemoglobin concentration, red blood cell count, hematocrit and lymphocyte count were lower. In the very elderly patients the study shows a biochemical feature suggesting delayed hospitalization for myocardial infarction, that may contribute to their poorer prognosis. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved
Association between fibrinogen plasma levels and platelet counts in an outpatient population and in patients with coronary heart disease
No full textAlthough numerous studies concern fibrinogen (FBG) associations, the relationship between platelet (PLT) count and FBG plasma levels has yet to be completely investigated. The present study concerns the association between FBG plasma levels and PLT count in 5891 patients (2831 men and 3060 women) attending our outpatients' laboratory. Of these, a subgroup of 4116 patients (1899 men and 2217 women) with normal values of the parameters investigated was selected. A group of 170 patients with coronary heart disease was also included. The parameters studied were FBG, PLT count, leukocyte count and age. Our results showed that, in the outpatient population, FBG was significantly correlated with the PLT count (P < 0.000001) and, as previously reported, with the leukocyte count and age. In the patients with coronary heart disease, there was a significant correlation between FBG and PLT count (P < 0.000001), to be considered very significant considering the limited number of patients, whereas no correlation with age or leukocyte count was found. The role of interleukin-6, both in FBG and PLT production, is well known and may explain the correlation between these two parameters. The association of FBG and PLT count has yet to be fully investigated in epidemiological studies, even though they play an important role as two of the major contributors to the pathogenesis and evolution of cardiovascular diseases. Blood Coagul Fibrinolysis 21:216-220 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins
Antithrombin III metabolism in the pulmonary vessel endothelium
No full textIn 85 patients undergoing aorto-coronary bypass for atherosclerotic coronary disease, we measured the antithrombin III activity levels and the thrombin-antithrombin III complex concentrations in blood from the pulmonary and the radial arteries, taken before the aorto-coronary bypass procedure, with the aim of investigating the role of the pulmonary endothelium in the metabolism of the inhibitor. Results showed significantly lower mean antithrombin III activity levels, expressed as a percentage of normal plasma, in blood from the radial artery with respect to levels from the pulmonary artery (0.78 +/- 0.12 versus 0.80 +/- 0.12, P < 0.0001), while no significant difference was found in thrombin-antithrombin III complex concentrations. The results seem to show that the pulmonary endothelium contributes to the antithrombin III metabolism with a 0.023 breakdown rate, corresponding to about a 0.1 fraction of the reported 0.22-0.25 total body catabolic rate, as well as the pulmonary endothelial surface (50-70 m(2)) corresponding to about a 0.1 fraction of the peripheral vessels' endothelial surface (500-700 m(2)). The data support the hypothesis of a main endothelial catabolism of antithrombin III
Fibrinogen metabolism in the lungs
No full textThe aim of this study was to evaluate the role of the pulmonary vessel endothelium in the metabolism of fibrinogen (FBG), by measuring the FBG, D-dimer, and fibrin(ogen) degradation product levels in the blood from pulmonary and radial arteries from 99 patients undergoing aortocoronary bypass. For comparison, protein C, protein S, and factor VII, were also measured. The results showed, with respect to the pulmonary arterial blood levels, significantly lower FBG levels (3.72 +/- 0.83 vs 3.66 +/- 0.81 g/L; P < .001) and higher fibrin(ogen) degradation product levels (7.36 +/- 1.53 vs 8.15 +/- 1.59 mg/L; P < .00001) in the radial arterial blood. No difference was found for D-dimer, protein C, protein S, and factor VII. The study demonstrated that the pulmonary capillary endothelium contributes to the FBG catabolism for about a 0.02 fractional rate and support the view of an endothelial FBG catabolic pathway as the main catabolic pathway, owing to the fact that the pulmonary endothelial surface is about a 0.1 fraction of the peripheral vessel endothelial surface. (C) 2005 Elsevier Inc. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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