1,721,036 research outputs found
XXXI National Conference of the Italian Society of Cytometry (GIC) October 8–11, 2013, Lucca, Italy
No full textThis year, the Conference has been preceded by a half a day satellite event devoted to the establishment of the “Professional Certification GIC Register” which will be committed to test, train, certify, and monitor the professional levels of the “Italian Cytometrists” under the responsibility of GIC.As dfar as "Professional Qualification” is concerned, authors summarized the strategic importance in Italy (as everywhere in the world)
to apply a “formal-serious-system” to take care and guarantee the high Professional level of people (Beginners as well as Seniors) involved in the area of analytical cytometry especially those having clinical impacts. The “national governance” should have in mind the patients’ care and the scientific society will have a crucial role in these initiatives.
With regard to “The role of Flow Cytometry in the immunophenotyping of Acute Leukemia.” authors delivered extensive details of what the board of this Project did in the recent past and what the enrolled “Expert Committee” is doing in the evaluation of the selected literature, in order to define future steps of the activity, which is the real impact of Flow Cytometry in this very important and promising area of this technology application
Inhibition of mesenchymal stromal cells by pre-activated lymphocytes and their culture media.
No full textIntroduction:
Despite having a proven immunosuppressive potential in vitro, human mesenchymal stromal cells (MSCs) are reported to display variable efficacy in vivo and, in fact, their proven benefit in the clinical practice is still limited and controversial.
Methods:
The interplay between clinical grade MSCs and pre-activated donor lymphocytes or selected lymphocyte subsets was studied in vitro. The kinetics of MSC growth and viability was evaluated by adhesion-dependent changes of culture plate impedance and biochemically by a colorimetric assay. Activation of natural killer (NK) cells was assessed as well, using a flow cytometry assay.
Results:
A strong inhibition of MSC growth was rapidly induced by the addition of pre-activated lymphocytes but not of resting lymphocytes. Inhibition seems not to be attributable to a single cell population, as similar results can be obtained by depleting NK cells or by using either selected CD4+ or CD8+ lymphocytes. In addition, conditioned medium (CM) from activated lymphocytes was able to inhibit MSC growth in a dose-dependent manner. Furthermore, licensing with IFN-γ partially protected MSCs from pre-activated lymphocytes but not from their CM. These results suggest an inhibitory role of lymphocyte-activation-derived substances. However, the identification of a single molecule responsible for MSC inhibition remained elusive, even if preliminary experiments showed that ATP and, to a lesser extent, TNF-α might play a role.
Conclusions:
These results suggest that survival of MSCs can be affected by soluble mediators released by activated lymphocytes. Thus it can be hypothesized that MSC immunosuppressive action in vivo could be impaired by ongoing immune activation through the release of inflammatory mediators
STAT5 Phosphorylation Status by Flow Cytometry Is a Rapid and Reliable Tool for Diagnosis and Follow up of Juvenile Myelomonocytic Leukemia
No full textIntroduction. Juvenile myelomonocytic leukemia (JMML) is a rare clonal myeloproliferative disorder of infancy and early childhood characterized by overproduction of myeloid cells (Aricò M et al., Blood, 1997) and selective hypersensitivity of the hematopoietic precursor cells to GM-CSF (Emanuel PD et al., Blood, 1991). Current diagnostic criteria are based on matched clinical presenting features and laboratory findings according to established international criteria (reviewed in Emanuel PD, Leukemia, 2008). Sometimes though, in the absence of some of these specific conditions, arriving to a conclusive diagnosis may be challenging. When a novel rapid phospho-specific flow cytometric assay (phospho-flow) is used, we and others have reported in vitro specific phosphorylated STAT5 (p-STAT5) signaling signature in JMML. (Gaipa G et al., Leukemia, 2008; Kotecha N et al., Cancer Cell, 2008). Aim and Methods. Here, in order to validate the p-STAT5 phospho-flow assay as a new integrated tool in the diagnostic work-up of JMML we analyzed mononuclear cells from 14 JMML patients at diagnosis, 39 control subjects and 6 patients diagnosed with suspected JMML which were subsequently not confirmed. Samples were stimulated with GM-CSF at 0, 0.01, 0.1, 1.0, and 10 ng/mL. p-STAT5-responsive cells were identified within the CD34+/CD33+ subset, and quantified by scaling the maximum % of p-STAT5+ cells at 100 and the % of unstimulated p-STAT5+ cells to 0 (Kotecha N et al.). JMMLs and controls were compared at each dose using Wilcoxon’s test in order to identify the best dose with lowest significative p-value after correction for multiplicity with a Bonferroni’s method. Discriminating p-STAT5 % value was identified as the mean between the lowest of the JMML p-STAT5 values and the highest of the control subjects. Results. We found that a threshold of 18.9 % of p-STAT5+ cells, after stimulation with 0.1 ng/mL GM-CSF (p <0.01) , was the best condition to discriminate JMMLs (n 8) from control subjects (n 27). This algorithm was then applied on an independent cohort of JMMLs (n 6), control subject (n 12) and patients with suspected diagnosis of JMML subsequently not confirmed (n 6) and reached concordant results with a sensitivity of 0.83 and a specificity of 1.0 was reached. Positive and negative predictive values were 1.0 and 0.94, respectively. We also applied p-STAT5 phospho-flow assay in bone marrow aspirates from 3 JMML patients during one-year post- transplantation follow-up. Two of these 3 patients showed p-STAT5 value below the diagnostic threshold at any of time point (mean 9.71% [range 4.3%-10.6%], and 4.26% [range 0.26%-13.6%]), chimerism analysis and morphology examinations confirmed the remission status. The third patients relapsed 3 months after transplantation with a p-STAT5 value of 21.5% which increased to 41.1% one month later together with clinical disease progression. Conclusions. Patients with JMML show p-STAT5 hyper-responsiveness, and this condition can be rapidly assayed by phospho-flow technology in routine diagnostic work-up with high sensitivity and specificity, under appropriated technical standardization. Although we tested a very limited series of patients, our results also show that p-STAT5 response may represent a surrogate marker of disease activity in post-transplantation follow-up of JMML patients with potential clinical impact
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
ABERRANT GM-CSF SIGNAL TRANSDUCTION PATHWAY IN JUVENILE MYELOMONOCYTIC LEUKEMIA BY FLOW CYTOMETRY: RELIABILITY OF A RETROSPECTIVE STUDY
No full textDispelling 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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