1,720,992 research outputs found
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
Immunophenotypic and genotypic characterization of chronic lymphocytic leukemia patients from northern Italy
No full textBackground and methods: Immunoglobulin (Ig) gene expression and rearrangements provide information about cell lineage, clonality and differentiation of neoplastic lymphoid cells. We performed flow cytometry and Southern blot analysis in 25 patients with chronic lymphocytic leukemia (CLL) from the Po River delta region (Northern Italy), in order to correlate surface immunological phenotype and heavy and light chain gene rearrangements with clinical stages.
Results: In these 25 CLL cases, as in the larger group of 165, k-positive (k+) patients were more frequent than lambda-positive (lambda +) ones by a ratio of 59:41, with a predominance of lambda + in stage II (46:54) and of K+ in stage IV (77:23). However, the survival behavior of lambda + and k+ patients was not statistically different. Ig gene rearrangements were found in all patients in accordance with the immunophenotype. When Ig gene analysis was performed on two different occasions in 7 of the 8 who received chemotherapy, there was an increase in the percentage of the germline band. This variation was inversely related to changes in WBC count. In the treated subject who showed a reduction of both WBC count and the germline, there was rapid disease progression and short survival.
Conclusions: Analysis of Ig gene rearrangements in our CLL patients demonstrated: i) the monoclonality of neoplastic cells; ii) no correlation between rearrangements and clinical stages, and iii) that this analysis may be a useful tool in evaluating biological behavior in selected CLL cases showing a discrepancy between hematological data and clinical response to therapy
Flow cytochemical analysis of peripheral lymphocytes in chronic B-lymphocytic leukemia. Prognostic role of the blast count determined by the H1 system and its correlation with morphologic features
No full textPeripheral blood samples from 148 previously untreated patients with chronic B-lymphocytic leukemia (B-CLL) were analyzed with the Technicon H*1 flow cytometer. The absolute number and the percentage values of both LUCs (large unstained cells) and blasts were correlated with survival, as well as with well-known prognostic factors including morphological subtypes of lymphoid cells. Results showed that patients at the most advanced clinical stages (Rai: III and IV; Binet: C) had the highest percentage and count of both LUCs and blasts. Furthermore, the proportion of LUC positively correlated with the following prognostic factors: peripheral lymphocytosis (greater than 50 x 10(9)/l); marked splenomegaly (greater than 10 cm UCM); % of circulating prolymphocytes, % immunoblasts, and % LGL. Our data analysis further revealed that chemotherapy produced a greater reduction of both the LUCs and of the blast count than of that of small lymphocytes. An increase in LUC count was found to coincide with deterioration of clinical status (progressive changes in the clinical stages, occurrence of prolymphocytoid transformation). A rapid increase in blast count was found to occur in concomitance with the development of Richter's syndrome, and correlated positively with the number of peripheral immunoblasts determined by light microscopy. Moreover, a blast percentage higher than 7% had the strongest predictive relation to survival rate when compared with other hematological parameters (lymphocytosis greater than 50 x 10(9)/l, % of LUCs greater than 12%, LUC to lymphocyte ratio greater than 16%, LUCs count greater than 2.2 x 10(9)/l). In the light of these findings, it may be suggested that the presence both of larger proportions of LUCs and of blasts measured with the flow cytometry may be considered unfavorable prognostic factors in B-CLL. However, based on morphological and multivariate statistical analyses, the blast count proved to be the most important prognostic parameter determined by the H*1 system in B-CLL
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
Flow cytometric analysis of anti-platelet antibodies in idiopatic thrombocytopenic purpura
No full textAnti-platelet antibody measurement may be important in defining the pathogenesis of thrombocytopenic states. In this paper we compared three anti-human immunoglobulin reagents by using them to detect anti-platelet antibodies on the platelet surface and in the serum of 14 patients with chronic idiopathic thrombocytopenic purpura (ITP) and 22 thrombocytopenic disorders. Samples were analyzed by both flow cytometry and a fluorescence microscope. In ITP patients, the direct test was positive in 50% of the cases, while the indirect technique proved to be positive in a slightly higher number of those tested (56%). Furthermore, the number of positive cases was similar for the three reagents used in this study, although the mean percentage of positive platelets was higher for the kappa/lambda monoclonal reagent. These data further support the sensitivity and reproducibility of flow cytometry analysis, which was capable of detecting antiplatelet antibodies in all patients with transfused Cooley's disease (regarded as positive control), as well as in a significant number of patients with ITP or related diseases. On the basis of the data presented here, definitive proof regarding the presence of anti-platelet antibodies in patients with thrombocytopenia still has to be found, and further studies are needed in order to ascertain the autoimmune nature of these disorders
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
Comparative analysis of different permeabilization methods for the flow cytometry measurement of cytoplasmic MPO and lysozyme in normal and leukemic cells
No full textUsing a direct one-color (fluorescein isothiocyanate; FITC) staining method with a Facscan flow cytometer, we evaluated the intracellular expression of two granular constituents of myeloid cells [myeloperoxidase (MPO) and lysozyme] on leukemic cells from 21 patients with acute myeloid leukemia (AML), and 6 patients with acute lymphoblastic leukemia (ALL). Three different permeabilization techniques were used [FACS Lysing Solution (FLy), B.Dis; Ortho-PermeaFix (OPF); Fix and Perm (F&P), Caltag] prior to monoclonal antibody (McAb) staining, in order to verify the specificity and the sensitivity of the three labelling methods towards the two model antigens. Peripheral blood cells from 15 healthy subjects and Ortho Absolute Control served as controls. Data were expressed as percentage of positivity, net fluorescence intensity, ratio between mean fluorescence intensity (MFI) of positive cells and that of isotypic controls (P/N ratio; evaluated in both geometric and arithmetic scale), and, in 12 representatives cases (7 AML, 5 normal samples), in the form of both molecules of equivalent soluble fluorochromes (MESF) and antibody binding capacities (ABC). As far as the antigenic expression of MPO and lysozyme in normal samples is concerned, F&P resulted, in our hands, in the most specific and sensitive staining, followed by FLy solution and OPF, which showed positivity for MPO, and, to lesser extent, for lysozyme in a considerable manner of lymphocytes (means 64% and 54%, respectively, for OPF and FLy; range of ABC/cell: 0.9-5.2 x 10(3)) obtained from healthy subjects. With the reference F&P permeabilizing solution, 90% and 80% of FAB M1-M5 cases were found to be positive for MPO and lysozyme, respectively. However, M1, M2, and M3 AML FAB (French-American-British) subvarieties were characterized by a brighter expression for MPO (mean ABC/cell: 89 x 10(3)) than that of lysozyme (mean ABC/cell: 12.5 x 10(3D)), whereas blast cells from patients with M5a FAB subtypes showed higher levels of lysozyme (mean ABC/cell: 65 x 10(3)) than that of MPO (mean ABC/cell: 0.1 x 10(3)). One of five cases of FAB MO AML showed a dull positivity for MPO-7 McAb. Patients with ALL were MPO and lysozyme negative using both F&P and FLy reagents, although a certain degree of positivity was documented in some cases with OPF. Taking these data together, it can be stated that the use of anti-MPO McAbs may be of great value for the diagnosis and monitoring of acute leukemia and, along with lysozyme McAb, can provide useful information in the distinction of myeloid from monocytic leukemias and in the lineage assignment of apparently biphenotypic forms. However, the methodology used for the detection of these myeloid-associated antigens is critical for a correct interpretation of cytofluorimetric data and should be taken into account when evaluating data coming from multicenter trials dealing with leukemias. A standardization of cytofluorimetric analysis of intracellular antigens is needed in order to improve the reproducibility and comparability of results in multicenter studies
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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