1,721,002 research outputs found
Use of stem cells from mismatched related donors.
No full textMismatched haploidentical bone marrow transplantations from a related donor have been the topic of clinical and laboratory research for more than 20 years. During that time, new treatment strategies have been designed based on animal experiments, and, since our group introduced the megadose inoculum which combines T-cell-depleted bone marrow cells with a large number of granulocyte colony-stimulating factor-mobilized peripheral blood stem cells and a more intensive conditioning regimen, have done much to overcome the problems of graft-versus-host disease and graft rejection. As most patients have a full haplotype mismatched relative available, this technique means that a far greater number of patients with hematologic malignancies can be offered a T-cell-depleted transplantation as curative therapy
Hematopoietic stem cell transplantation from alternative sources in adults with high-risk acute leukemia.
No full textSince 75% of patients with high-risk acute leukemia do not have a human leukocyte antigen (HLA)-identical sibling, alternative sources for hematopoietic stem cell transplantation (HSCT) are matched unrelated donors (MUD), unrelated umbilical cord blood (UD-UCB) and one HLA haplotype mismatched family members (haploidentical). The chance of finding a suitable donor in the international voluntary donor registries is limited by frequency of the HLA phenotype and the time required to identify the right donor from a potential panel, to establish eligibility and to harvest the cells. In adult MUD recipients, event-free survival ranges up to 50% and refers only to patients who undergo transplant, without taking into account those who do not find a donor. Umbilical cord blood offers the advantages of easy procurement, the absence of risks to donors, the reduced risk of transmitting infections, immediate availability of cryopreserved samples and acceptance of mismatches at two of the six antigens. Although UD-UCB transplantation is a viable option for children, it is seldom considered for adults. The great divergency between body weight and the number of hematopoietic cells in a standard cord blood unit, particularly if associated with a two-antigen mismatch, increases the risk of graft failure and delays hematopoietic reconstitution. Work on full-haplotype mismatched transplants has been proceeding for over 20 years. Originally, outcome in leukemia patients was disappointing because of high incidence of severe graft-vs.-host disease in T-replete transplants and high rejection rates in T-cell-depleted transplants. The breakthrough came with the use of a megadose of T-cell-depleted progenitor cells after a high-intensity conditioning regimen. Treating end-stage patients inevitably confounded clinical outcome in the early pilot studies. Today, high-risk acute leukemia patients are treated at less advanced stages of disease, receive a reasonably well tolerated conditioning regimen, and benefit from advances in post-transplant immunological reconstitution. All these factors contribute to markedly reduce transplant-related mortality. Overall, event-free survival and transplant-related mortality compare favorably with reports from unrelated matched transplants. T-cell-depleted megadose stem cell transplant from a mismatched family member, who is immediately available, can be offered as a viable option to candidates with high-risk acute leukemias
The haploidentical option for high-risk haematological malignancies.
No full textMuch progress has been made in the clinical, biological and technical aspects of the T-cell-depleted full-haplotype mismatched transplants for acute leukaemia. Our experience demonstrates that infusing a megadose of extensively T-cell-depleted haematopoietic peripheral blood stem cells after an immuno-myeloablative conditioning regimen in acute leukaemia patients ensures sustained engraftment with minimal GvHD without the need of any post-transplant immunosuppressive treatment. Since our first successful pilot study, our efforts have concentrated on developing new conditioning regimens, optimising the graft processing and improving the post-transplant immunological recovery. The results we have so far achieved in more than 200 high-risk acute leukaemia patients show that haploidentical transplantation is now a clinical reality. Because virtually all patients have a mismatched family member, who is immediately available, mismatched transplantation should be offered as a viable option to high-risk acute leukaemia patients who do not have, or cannot find, a matched donor
Haploidentical stem cell transplantation in leukemia.
No full textIn acute leukemia patients, infusing a megadose of extensively T-cell-depleted hematopoietic stem cells after an immuno-myeloablative conditioning regimen ensures sustained engraftment of full-haplotype mismatched transplants without graft-vs-host disease. Besides the conditioning regimen and the megadose of stem cells donor natural killer cell alloreactivity also plays a role in facilitating engraftment and in preventing relapse. Since our first successful pilot study, our efforts have concentrated on developing new conditioning regimens, optimizing the graft processing and improving the post-transplant immunological recovery. The results we have so far achieved in 112 very high-risk acute leukemia patients show that haploidentical transplantation is now a clinical reality. Because virtually all patients in need of a hematopoietic stem cell transplant have a full-haplotype mismatched donor, who is immediately available, a T-cell depleted mismatched transplant should be offered, not as a last resort, but as a viable option to high risk acute leukemia patients who do not have, or cannot find, a matched donor
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
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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