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REPLY to “Association Between Plasmatic Oxidative Stress and Thrombosis in Primary Antiphospholipid Syndrome”
No full textWe read with great interest the article by Vaz et al. who investigated markers of oxidative stress in 70 thrombotic primary antiphospholipid patients (PAPS) and in 74 controls [1]: the authors were surprised not to fnd elevated plasma levels of such markers, amongst which 8-isoprostanes, in their PAPS population; this seem contrary to what was found in a recent meta-analysis, where pooled data from PAPS patients showed higher urinary/plasma concentrations of 8-isoprostanes compared to systemic lupus erythematosus with APS and to systemic lupus without APS [2]. There are potential explanations for the discrepancy noted by Vaz et al. in terms of methodology of 8-isoprostane measurement, patient population, comorbidities, treatment and expression of antiphospholipid antibody results. With regards to the frst issue, plain immunoassays for 8-isoprostane, not preceded by a purifcation step, are poorly reliable in plasma and less so in urine owing to the cross-reactivity between several prostaglandins and to the binding of the antibody that may be hampered by impurities, therefore underestimating true values [3]. In addition, total antioxidant capacity is a non-specifc method to assess oxidative imbalance; a more specifc assay evaluating specifc antioxidant pathways, such as the blood hydrogen peroxide break-down activity may provide more precise and reliable results
Eosinophilia and thrombophilia in churg strauss syndrome: A clinical and pathogenetic overview
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Earlier onset of peripheral arterial thrombosis in homozygous MTHFR C677T carriers than in other MTHFR genotypes: a cohort study
No full textTo investigate whether age at first presentation of pure peripheral arterial thrombosis (PAT) in lower and upper limbs and in the splanchnic circulation occurs earlier in carriers of the methylenetetrahydrofolate reductase (MTHFR) T677T genotype compared to the heterozygous and wild type and to identify predictors of a possible earlier onset. Retrospective cohort study on 27 MTHFR TT, 29 MTHFR TC and 29 MTHFR CC participants; data regarding age, sex, age at PAT, clinical history (dyslipidaemia, hypertension, smoking, obesity) and homocysteine (HC) measured by immunoassay were collected. Age at PAT was lower in MTHFR TT than MTHFR TC and CC (43 +/- 9 vs 47 +/- 9 vs 51 +/- 4 years, respectively, p = 0.02); plasma HC was higher in MTHFR TT than in the other groups (25 +/- 19 vs 12.7 +/- 6.7 vs 11.3 +/- 3.3 mu mol/l, respectively, p < 0.001) while the activated partial thromboplastin ratio (aPTTr) was lower in MTHFR TT than in other genotypes (0.90 +/- 0.10 vs 0.97 +/- 0.12 vs 0.97 +/- 0.08 mu mol/L p < 0.001). Among categorical variables, MTHFR TT and dyslipidaemia independently predicted age at AT (p = 0.01 & p = 0.03, respectively) whereas among the continuous variables HC independently predicted age at PAT (p = 0.02) as well as the aPTTr (p = 0.001); smoking predicted lower limb PAT (p = 0.005). MTHFR TT carriers develop their first PAT an average of 4 and 8 years earlier than MTHF CT and CC genotypes; MTHFR TT, dyslipidaemia and plasma HC contribute to the prematurity of the PAT while the interplay between elevated HC and smoking may affect type of arterial district occlusion
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Validity of coagulation activation markers in antiphospholipid syndrome: a systematic review and meta-analysis with a short data report
No full textProthrombin fragment F1 + 2 (F1 + 2) and thrombin-antithrombin (TAT) have been assessed in antiphospholipid syndrome (APS) but without evaluating a direct relationship with antiphospholipid (aPL) antibody titers. This article aims to investigate a direct relationship between aPL and F1 + 2 and perform a systematic review and meta-analysis of F1 + 2 and TAT in APS. Systematic search was performed using EMBASE and PubMed databases from January 1982 to December 2018 and random effects meta-analyses for continuous outcomes. This is a cross-sectional case-control study; immunoglobulin G/immunoglobulin M (IgG/IgM) anticardiolipin (aCL) anti-β 2 -glycoprotein-I, antiprothrombin (aPT) antibodies, F1 + 2, and lupus anticoagulants (LA) were measured in 25 thrombotic primary APS (PAPS), 9 nonthrombotic carriers of aPL, and 18 controls. The significant effect size (ES) for F1 + 2 between aPL +ve and aPL -ve systemic lupus erythematosus (SLE) and between aPL +ve SLE and control displayed high heterogeneity. The significant ES for F1 + 2 between aPL -ve SLE and controls displayed no heterogeneity. The ES for TAT between aPL +ve and aPL -ve SLE patients and between aPL -ve SLE and controls was low, without heterogeneity. Mean F1 + 2 was greater in PAPS (p < 0.0001), inversely correlated with IgG aCL, IgM aPT, and LA (p = 0.001, 0.03, and 0.01, respectively), though only IgG aCL negatively predicted F1 + 2 (p = 0.01). IgG aCL inversely predicts F1 + 2. IgG aCL positivity introduces heterogeneity in the F1 + 2 ES, whereas the lack of heterogeneity in the ES for TAT may indicate poor TAT formation in aPL +ve group. Thus, F1 + 2 measurements may be unfounded as already demonstrated for TAT in the 1990s
Intensity of immune/clotting assays relate to multiple antiphospholipid antibody positivity in thrombotic primary antiphospholipid syndrome
No full textThe dual positivity (DP) and triple positivity (TP) concepts bypass the poor comparability of immune/clotting assay for the laboratory classification of antiphospholipid syndrome (APS). To evaluate intensity of immune/clotting assays and DP/TP through different clinical severity groups (CSG) as follows: (1) non-thrombotic asymptomatic carriers of aPL (N-THR), thrombotic primary APS (THR), deceased (D) for recurrent and fatal thrombosis. Activated partial thromboplastin time ratio (aPTTr), dilute Russell viper venom time ratio (DRVVTr), IgG/IgM anticardiolipin (aCL) and anti β-2-glycoprotein-I (aβ2GPI). Participants: 33 N-THR, 64 THR and 11 D. The frequency of DP and TP (DRVVTr or aPTTr partnered with respective IgG aCL or aβ2GPI) increased across CSG (p = 0.006 and p = 0.003); mean DRVVTr and IgG aCL/aβ2GPI were always greater in TP versus non-TP within each CSG and progressively increased across the CSG. The intensity of individual lupus anticoagulants partnered with their corresponding IgG aPL related to the frequency of multiple positivity throughout CSG suggesting that of intensity of immune/clotting assays and multiple positivity are the different faces of the same diagnostic coin in our thrombotic PAPS cohort
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