1,720,975 research outputs found
In vivo measurements of fibrin formation and degradation in nephrotic patients
No full textIntraglomerular fibrin deposition has been implicated as an important pathogenetic mechanism in patients with glomerular diseases and the nephrotic syndrome. To investigate fibrin formation and degradation in nephrosis, we measured fibrinopeptide A by radioimmunoassay and D-dimer by enzyme-linked immunosorbent assay in the plasma of 30 consecutive adult patients with the nephrotic syndrome; in 10 the serum creatinine was more than 2 mg/dl. Both fibrinopeptide A and D-dimer were abnormally elevated in the majority of nephrotics (P < 0.001 vs. healthy controls), providing evidence of increased fibrin generation and lysis "in vivo." A positive correlation was found between fibrinopeptide A and D-dimer (correlation coefficient 0.64, P < 0.001), suggesting a close relationship between fibrin formation and degradation. Calcium heparin, administered to 12 nephrotics, caused a marked decrease in plasma fibrinopeptide A, due to a reduction of in vivo thrombin activity. As enhanced thrombin activity can favor fibrin deposition within the renal parenchyma, as well as vascular complications, it is reasonable to assume that an antithrombotic treatment aimed at controlling thrombin generation may ameliorate the natural history of nephrosis
Plasma parameters of the prothrombotic state in chronic uremia
No full textWe measured plasma parameters of the prothrombotic state, namely thrombin-antithrombin III complex (TAT), fibrinopeptide A (FPA). D-dimer (DD), von Willebrand factor (vWF), tissue-type plasminogen activator (tPA), beta-thromboglobulin (beta TG), platelet factor 4 (PF4) and serotonin (5HT) in a series of 51 adult patients with chronic uremia: 22 were on maintenance hemodialysis (MHD) and 29 on conservative dietary treatment. Serum tumor necrosis factor alpha (TNF) was determined as well. Uremics presented significantly higher levels of TAT, FPA, DD, vWF, TNF, beta TG and 5HT than normal controls. Patients on conservative treatment showed lower levels of TAT, DD, TNF and beta TG than patients on MHD. Our results provide evidence that a prothrombotic state exists in chronic uremia and that MHD patients have a higher degree of hypercoagulation. Both hemodialysis procedure and uremia-related factors are likely to contribute to the hemostatic derangement
The measurement of plasma D-dimer (DD) levels in the follow-up of patients with ovarian cancer
No full textPeripheral blood samples for the measurement of DD and CA 125 were drawn from 39 patients with ovarian cancer at different times from first surgery. Both median DD and CA 125 levels were significantly higher in the 20 samples drawn from patients with clinically evident disease than in the 37 samples from patients without clinical evidence of disease (477 vs 300 ng/ml p = 0.006, and 66 vs 11 U/ml, p < 0.0001, respectively). DD levels did not correlate with CA 125 levels. The sensitivity, specificity and diagnostic accuracy of the tests in the assessment of clinical disease status were as follows: 65%, 62% and 63% for DD (cut-off = 416 ng/ml); 70%, 92% and 84% for CA 125 (cut-off = 35 U/ml); 90%, 59% and 70% for DD "or" CA 125; and 45%, 95% and 77% for DD "and" CA 125. DD levels correlated with the clinical course of disease in ovarian cancer patients. However, the concomitant determination of DD and CA 125 did not improve the reliability of CA 125 assay alone in the follow-up of these patients
Preoperative D-dimer plasma assay is not a predictor of clinical outcome for patients with advanced ovarian cancer
No full textD-dimer (DD) plasma levels are significantly higher in patients with ovarian cancer than in those with benign ovarian masses. The aim of this paper is to assess whether preoperative DD plasma assay has a prognostic relevance for 35 patients with advanced ovarian cancer receiving platinum-based chemotherapy. Preoperative DD levels ranged from 162 to 3720 ng/ml. The 25, 50, and 75% quartiles of DD levels were 1600, 1894, and 2069 ng/ml, respectively. Preoperative DD levels correlated neither with the common clinicopathological prognostic variables nor with the disease status at the end of first-line chemotherapy. Survival was related to residual disease after initial surgery (> or =2 cm vs <2 cm, P = 0.003), but not to preoperative DD levels. In conclusion, the present data seem to show that preoperative DD plasma assay is not a predictor of clinical outcome for patients with advanced ovarian cancer
Preoperative evaluation of D-dimer and CA 125 levels in differentiating benign from malignant ovarian masses
No full textPlasma levels of D-dimer (DD) and CA 125 were measured preoperatively in 121 patients with ovarian masses submitted to laparotomy. DD and CA 125 levels were higher in the 56 patients with epithelial ovarian cancer than in the 65 patients with benign ovarian disease (P 416 ng/ml) in 73% of FIGO stage I patients, whereas CA 125 was above 65 U/ml in only 33.3%. Sensitivity, specificity, positive predictive value, and negative predictive value of the tests in differentiating benign from malignant ovarian masses were as follows: 76.8, 93.8, 91.5, and 82.4%, respectively, for CA 125; 94.6, 76.9, 77.9, and 94.3%, respectively, for the combination CA 125 or DD; and 73.2, 100.0, 100.0, and 81.3%, respectively, for the combination CA 125 and DD. The combination CA 125 and DD seems to be a useful diagnostic tool to differentiate benign from malignant ovarian masses. Elevated preoperative levels of both antigens are invariably associated with a postsurgical diagnosis of epithelial ovarian cancer
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
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