1,721,007 research outputs found
Late effects in children after bone marrow transplantation: a review
No full textSince the number of children receiving a bone marrow transplantation (BMT) and becoming long-term survivors continues to increase, more attention has to be paid to detect long-term side effects in these unique patients. Follow-up studies to timely identify these untoward sequelae are a matter of particular concern for pediatricians due to the longer life expectancy of children cured by BMT. The more frequently recognized sequelae affecting lung, eyes, brain and the endocrine system have been analyzed in this review. The majority of long-term side effects could be related to the conditioning regimens employed to prepare children before marrow transplantation and radiotherapy has been indicated as the most important agent determining deleterious toxicities. Most children receiving BMT present a decreased growth velocity and this growth impairment is especially observed in patients receiving total body irradiation (TBI) and prophylactic cranial irradiation prior to marrow transplant. Growth hormone deficiency could be demonstrated in the majority of patients with a reduced growth rate, even though an impairment of liver somatomedin production or a direct radiation-induced skeletal dysplasia could not be excluded. Overt and compensated hypothyroidism have been reported after TBI and patients given single dose radiotherapy are at greater risk with an overall incidence of thyroid function abnormalities approaching 30-40%. Delayed puberty development was reported in boys and girls after a TBI-containing conditioning regimen, whereas patients given BMT for severe aplastic anaemia presented a normal puberty. The absence of pubertal growth spurt contributes to the growth impairment of prepubertal children. In post-pubertal patients amenorrhea, azoospermia and gonadal failure can be observed after radiotherapy and several patients can require hormonal substitutive therapy. Skin and mucosal abnormalities referred to teguments involvement by chronic graft-versus-host disease (GVHD). Moreover, alopecia or abnormal pigmentation of the skin are observed in patients given busulfan as part of their myeloablative therapy. Cataracts are a well recognized complication of children receiving ionizing radiations and chronic steroid therapy. Again, posterior subcapsular cataracts occur more frequently in patients given TB1 as single exposure. Decreased lacrimal gland function, with impairment of tear production is another late effect of irradiation to the eye. Lung function abnormalities are not rare after transplant and may cause late mortality and morbidity
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
Lung function abnormalities after bone marrow transplantation in children: has the trend recently changed?
No full textTo evaluate early and late lung function abnormalities and their predictors in a large sample of children who underwent bone marrow transplantation (BMT) for leukemias in the 1990s, highlighting changes with respect to the 1980s. Prospective cohort. Seventy-five consecutive children who underwent BMT were enrolled in the study (median age, 11 years; range, 6 to 19 years; 45 male and 30 female children). Twenty-three children received autologous BMT, and 52 children received allogeneic BMT; 50 children completed the study. Clinical examinations and lung function tests were performed before BMT, and 3 to 6 months, 12 months, and 24 months after BMT. Before BMT, at 3 to 6 months after BMT, and at 24 months after BMT, 44%, 85%, and 62% of children, respectively, had altered lung function in the absence of persistent respiratory symptoms. Between 3 months and 6 months after BMT, a restrictive pattern was the most frequent abnormality. The only predictive factors for late abnormalities were transplantation performed in the advanced disease phase (odds ratio [OR], 6.75; p = 0.005) and bronchopulmonary infections (OR, 3.9; p < 0.05). These data suggest that a significant proportion of children who undergo BMT, especially if for leukemia in advanced phase, have early and late pulmonary abnormalities. These abnormalities, especially the late ones, seem to be more severe than patients reported in studies analyzing children undergoing BMT in the 1980s. This could be due to the more intensive front-line treatment protocols employed for treatment of children with acute leukemia in the 1990s
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
Cord blood transplantation provides better reconstitution of hematopoietic reservoir as compared to bone marrow transplantation
No full textDelayed hematopoietic recovery is the main factor precluding a wider use of cord blood (CB) transplants. We hypothesized that this delayed engraftment might not be related to an insufficient number of stem cells in the graft, but to an intrinsic difficulty of these cells to undergo differentiation. To test our hypothesis, 2 groups of children were compared; 12 received a CB transplant and 12 an adult bone marrow (BM) transplant. We studied neutrophil and platelet recovery and, at a median time of approximately 1 year after transplantation, the frequency of colony-forming cells (CFCs) and long-term culture initiating cells (LTC-ICs) in the BM of the 2 groups. Recipients of BM transplants received 1-log more cells and had significantly faster neutrophil and platelet recovery. Conversely, the frequency of committed and early progenitors was significantly higher in the BM of children given CB cells compared with BM transplant recipients (median count of CFC/2 x 10(4) BM mononuclear cells, 20 versus 11, P =.007; median count of LTC-IC/10(6) BM mononuclear cells, 8.2 versus 0.2 P =.001). CB, but not adult BM stem cells, can better restore the host hematopoietic progenitor cell reservoir; the delayed engraftment after CB transplantation may reflect the difficulty of CB progenitors to reprogram themselves toward differentiation
Resolution of immune haemolytic anaemia with allogeneic bone marrow transplantation after unsuccessful autograft
No full textAutologous transplantation of lymphocyte-depleted peripheral blood stem cells (PBSC) has been proposed for treatment of patients with severe autoimmune disease. However, several patients have been reported to achieve only transient remissions. We report on a child with thalassaemia intermedia and immune-mediated haemolytic anaemia, given an autologous lymphocyte-depleted PBSC transplant, who relapsed 7 weeks after transplant. A complete remission, lasting 18 months to date, was obtained with allogeneic bone marrow transplantation (BMT) from an HLA-matched unrelated donor. This experience indicates that, in selected cases, allogeneic BMT may be the treatment of choice for life-threatening autoimmune disease. A graft-versus-autoimmunity effect may favour the eradication of the recipient autoaggressive lymphocytes
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