1,721,037 research outputs found
Il laboratorio nel trapianto di midollo. Tecniche immunodiagnostiche: leucemie e immunodeficienze
No full textIl Laboratorio nel trapianto di midollo. Tecniche immunodiagnostiche in pediatria:leucemie e immunodeficienze
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Surveillance of cytomegalovirus infections in bone marrow transplant in Trieste: seven years' experience.
No full textThe immunosuppressive effect of Wharton's jelly stromal cells depends on the timing of their licensing and on lymphocyte activation
No full textBACKGROUND: Mesenchymal stromal cells (MSC) have been proven to have potent immunosuppressive action and hence have been proposed for the treatment of severe Graft Versus Host Disease. However, in most models, MSC were added at the same time of lymphocyte stimulation, which is quite different from what occurs in vivo. AIMS: To investigate how the timing of lymphocyte activation and the exposure to activation-related cytokines (licensing) can influence the immunosuppressive action of Wharton's jelly stromal cells (WJSC). METHODS: WJSC, licensed or not with activation-related cytokines, were added lymphocytes the same time or 24 hours after their stimulation with phytohaemoagglutinin. Proliferation of lymphocytes and cytokines production was measured after three days co-culture. RESULTS: Lymphocytes stimulated in the presence of WJSC displayed a dramatic decrease in proliferation and production of cytokines, in spite of normal expression of activation markers. The suppression was weakened when targeted lymphocytes were seperated by a membrane and partially rescued by the addition of exogenous l-tryptophan, suggesting a major role for indoleamine 2,3-dioxigenase with a probable paracrine effect. Licensing of WJSC increased the immunosuppressive effect, in both contact and non-contact settings. The timing of WJSC licensing was crucial for the immunosuppressive action. Lymphocytes pre-stimulated alone for 24 h, and added afterwards to non-licensed WJSC, showed normal or even increased proliferation. On the other hand, their proliferation was strongly inhibited by licensed WJSC. CONCLUSIONS: WJSC have a potent immunosuppressive function best realized with direct contact, and increased by licensing signals before and during lymphocyte stimulation. Our results could contribute to the set up of new WJSC-based therapies for severe autoimmuno disorders
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
Hemorrhagic cystitis in children undergoing bone marrow transplantation: aputative role for simian virus 40
No full textBACKGROUND: Late-onset hemorrhagic cystitis (HC) is a well-known severe complication of bone marrow transplantation (BMT), both in adults and in children. Protracted postengraftment HC is associated with graft-versus-host disease and viral infections, mainly caused by BK virus (BKV) or adenovirus (AV). This study investigated whether simian virus 40 (SV40) DNA sequences can be detected in specimens from pediatric patients affected by severe postengraftment HC. METHODS: The clinical diagnosis of HC was made in 7 of 28 BMT children. DNA from peripheral blood mononuclear cells (PBMC) and urine sediment cells and supernatants was analyzed by polymerase chain reaction (PCR) for human cytomegalovirus (HCMV), AV, BKV, JC virus (JCV), and SV40. DNA filter hybridization and sequencing was carried out in SV40-positive samples. RESULTS: SV40 footprints were detected in two of seven cases of HC. Specific SV40 DNA sequences were detected by PCR and by filter hybridization both in urine and in PBMC samples at the HC onset and during the follow-up. The DNA sequencing proved that the amplicons belonged to the SV40 wild-type. Urine samples of the two HC cases tested negative by cell cultures, PCR, or both for HCMV, BKV, JCV, and AV. CONCLUSIONS: The detection of SV40 DNA sequences suggest that this simian polyomavirus could be involved, at least in some cases, in the HC occurring in children after BMT
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