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Cyclosporin A absorption profiles in pediatric renal transplant recipients predict the risk of acute rejection.
No full textCyclosporin A absorption profiles in pediatric renal transplant recipients predict the risk of acute rejection.
No full text
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
The pharmacokinetic-pharmacodynamic relationship for total and free mycophenolic acid in pediatric renal transplant recipients: A report of the German Study Group on Mycophenolate Mofetil Therapy
No full textIt is currently being debated whether pharmacokinetic monitoring of mycophenolic acid (MPA), the active constituent of mycophenolate mofetil (MMF), can optimize MMF therapy after organ transplantation. This open-label longitudinal Study in pediatric renal transplant recipients was designed to investigate the pharmacokinetic (PK)/pharmacodynamic relationship of total and free MPA and to establish PK values for the assessment of an individual's MPA PK parameters. Fifty-four children, aged 2.2 to 17.8 yr, on an immunosuppressive triple regimen consisting of cyclosporin A, prednisone, and MMF (600 mg/m(2) body surface area twice daily) were investigated 1 wk and 3 wk (initial phase) and 3 mo and 6 mo (stable phase) after renal transplantation. MPA was measured by reverse phase HPLC, free MPA by HPLC after separation by ultrafiltration. There was an association between the risk of acute rejection episodes and MPA-AUC(0.12) values or MPA predose levels; by receiver operating characteristic analysis, an AUC(0-12) of 33.8 mg x h/L in the initial phase posttransplant had a diagnostic sensitivity of 7517c and a diagnostic specificity of 64% for discrimination of patients with acute rejections. The respective discrimination threshold for the MPA predose concentration was 1.2 mg/L with a sensitivity of 83% and a specificity of 64%. In contrast, high free, but not total, MPA-AUC(0.12) values were associated with an increased risk of the MMF-related side effects leukopenia and/or infections. These data indicate that therapeutic drug monitoring of MPA has the potential for optimization of MMF efficacy in this patient population by steering patients away from the low values of MPA PK variables that are associated with an increased rejection risk. For the assessment of the toxic risk of MMF regarding leukopenia and/or infections, measurement of free MPA appears to be more appropriate
Cyclosporin A absorption profiles in pediatric renal transplant recipients predict the risk of acute rejection
No full textThe Current focus of cyclosporin A (CsA) monitoring in adult transplantation for optimized immunosuppression is on the early portion of the CsA area Under the concentration-time curve (AUC), particularly in the first 4 hours postdose, designated as AUC(0-4), and on the blood concentration 2 hours postdose (C-2) as a highly predictive marker for AUC(0-4). Because data in pediatric patients are scarce, full-time (12 hours) and absorption profiles of CsA were analyzed in relation to CsA effectiveness in 61 pediatric renal transplant recipients aged 3.2 to 17.4 years on an immunosuppressive triple regimen with CsA, mycophenolate mofetil, and methylprednisolone. CsA dosing was based on body surface area and adjusted to CsA trough levels. Pharmacokinetic (PK) profiles were obtained 1 and 3 weeks (initial period) and 3 and 6 months posttransplant (stable period). Patients with an AUC(0-4) < 4400 mug(.)h/L at both PK sampling periods in the first 3 weeks posttransplant had an adjusted relative risk of 48.4% to suffer an acute rejection episode (ARE), whereas in patients with at least 1 AUC(0-4) above this threshold, the adjusted relative risk for an ARE was only 13.1% (P < 0.02). The single PK parameters C-0 or C-2 did not discriminate between patients with and without acute rejection. The PK parameters C-1.25 (r(2) = 0.64) or C-2 (r(2) = 0.60) showed a stronger relationship to the absorption profile (AUC(0-4)) than C-0 (r(2) = 0.15). An abbreviated profile consisting of the PK variables C-0.5.2 or C-0;0.5;2 showed the closest correlation to the absorption profile (r(2) = 0.89) and the lowest percentage prediction error. These data indicate that absorption profiling in pediatric renal transplant recipients has the potential to optimize immunosuppressive therapy with CsA
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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