Search results for "topoi"
showing 10 items of 701 documents
The hematopoietic niche: a Drosophila model, at last.
2007
The niche provides a specialised microenvironment necessary for maintenance of stem cells in a non differentiated state. While the hematopoietic stem cell (HSC) niche in vertebrates was the first to be recognized, Drosophila niches supporting germline stem cells were characterised first. Recent evidence for the existence of a niche maintaining hematopoietic precursors in Drosophila opens the way to study in vivo the niche/hematopoietic precursors interactions. The availability of a large collection of cell markers, mutants and sophisticated genetic tools makes Drosophila an attractive model for investigating the cellular and molecular mechanisms that are involved in these interactions.
Manganese effects on haematopoietic cells and circulating coelomocytes of Asterias rubens (Linnaeus)
2008
Abstract Manganese (Mn) is a naturally abundant metal in marine sediments where it mainly occurs as MnO 2 . During hypoxic conditions it is converted into a bioavailable state, Mn 2+ , and can reach levels that previously have shown effects on immune competent cells of the crustacean, Nephrops norvegicus . Here we investigated if Mn also affects circulating coelomocytes and their renewal in the common sea star, Asterias rubens , when exposed to concentrations of Mn that can be found in nature. When the sea stars were exposed to Mn it accumulated in the coelomic fluid and the number of circulating coelomocytes, in contrast to what was recorded in Nephrops , increased significantly. By using …
Human CD8+ memory and EBV-specific T cells show low alloreactivity in vitro and in CD34+ stem cell–engrafted NOD/SCID/IL-2Rγcnull mice
2013
Current strategies in cellular immunotherapy of cancer and viral infections include the adoptive transfer of T cell receptor (TCR) and chimeric antigen receptor engineered T cells. When using transient RNA expression systems in clinical studies, multiple infusions with receptor-redirected T cells appear necessary. However, in allogeneic hematopoietic stem-cell transplantation, repeated transfer of donor-derived T cells increases the risk of alloreactive graft-versus-host disease. We investigated naive-derived (T N ), memory-derived (T M ), and Epstein Barr virus-specific (T EBV ) CD8 + T cell subsets for alloreactivity upon redirection with RNA encoding a cytomegalovirus-specific model TCR.…
Gene expression of stem cells at different stages of ontological human development.
2013
Abstract Objectives To compare multipotent mesenchymal stem cells (MSCs) obtained from chorionic villi (CV), amniotic fluid (AF) and placenta, with regard to their phenotype and gene expression, in order to understand if MSCs derived from different extra-embryonic tissues, at different stages of human ontological development, present distinct stemness characteristics. Study design MSCs obtained from 30 samples of CV, 30 of AF and 10 placentas (obtained from elective caesarean sections) were compared. MSCs at second confluence cultures were characterized by immunophenotypic analysis with flow cytometry using FACS CANTO II. The expression of the genes Oct-4 (Octamer-binding transcription fact…
Identification and characterization of the human leiomyoma side population as putative tumor-initiating cells.
2012
Objective To isolate and characterize human leiomyoma stem cells by the side population (SP) method. Design Prospective experimental human and animal study. Setting University research laboratory-affiliated infertility clinic. Patient(s) Women undergoing laparoscopic myomectomy. Animal(s) Female non-obese diabetic severe combined immune deficiency (NOD-SCID) mutation mice. Intervention(s) Obtainment of human leiomyoma SP cells as candidate tumor-initiating cells and establishment of two leiomyoma SP lines. Main Outcome Measure(s) Flow cytometry, semiquantitative polymerase chain reaction, clonogenicity assays, cDNA microarrays hybridization, cell culture, karyotype, molecular analysis, immu…
Cytomegalovirus and varicella–zoster virus vaccines in hematopoietic stem cell transplantation
2009
Impairment of cellular immunity upon hematopoietic stem cell transplantation (HSCT) may lead to serious clinical manifestations induced by human cytomegalovirus (HCMV) and varicella-zoster virus (VZV) infections. Although the clinical presentations, preferential organ involvement and clinical courses are different, infections with both herpesviruses are similar with respect to many pathophysiological aspects and the therapeutic strategies that are employed to combat them. Antiviral drug prophylaxis and therapy are successfully used to limit the risk of reactivated HCMV and VZV infections, but are unable to absolutely prevent episodes of virus disease in long-term follow-up after HSCT. Contr…
Evaluating Human T-Cell Therapy of Cytomegalovirus Organ Disease in HLA-Transgenic Mice
2015
Reactivation of human cytomegalovirus (HCMV) can cause severe disease in recipients of hematopoietic stem cell transplantation. Although preclinical research in murine models as well as clinical trials have provided 'proof of concept' for infection control by pre-emptive CD8 T-cell immunotherapy, there exists no predictive model to experimentally evaluate parameters that determine antiviral efficacy of human T cells in terms of virus control in functional organs, prevention of organ disease, and host survival benefit. We here introduce a novel mouse model for testing HCMV epitope-specific human T cells. The HCMV UL83/pp65-derived NLV-peptide was presented by transgenic HLA-A2.1 in the conte…
Clinically-based determination of safe DNAemia cutoff levels for preemptive therapy or human cytomegalovirus infections in solid organ and hematopoie…
2004
Transplantation Centers using human cytomegalovirus (HCMV) antigenemia-based preemptive therapy will need to replace in the near future the antigenemia assay with a more standardized and automatable assay, such as a molecular assay quantifying HCMV DNA in blood (DNAemia). Thus, in view of replacing antigenemia with clinically safe cutoff values, DNAemia levels corresponding to antigenemia cutoffs guiding HCMV preemptive therapy were determined retrospectively in solid organ and hematopoietic stem cell transplant recipients (HSCTR) using an "in-house" quantitative PCR (QPCR) method. Since preemptive therapy had prevented appearance of HCMV disease in all patients tested, DNA cutoffs determin…
Fotballklubbers forankring og betydning i det norske samfunn : en casestudie av Viking fotballklubb
2008
Masteroppgave i idrettsvitenskap- Universitetet i Agder 2008 Fotballklubbers lokale forankring og betydning vil ses nærmere på gjennom teoretisk refleksjon og empirisk observasjon der Viking FK er case. Teorien som anvendes er Luhmanns systemteori og det som danner det empiriske materialet er dokumenter og kvalitative intervjuer. Ifølge Luhmann (2000a) er sosiale fenomen, som eksemplifisert ved Viking FK i denne avhandlingen, sosiale system som danner seg selv gjennom å skille seg fra omverden. Skille mellom systemet selv og dets omverden danner en unik betraktning av seg selv som noe forskjellig fra omverden. Det utgjør systemets realitetsforståelse, dets mening som uttrykkes gjennom forve…
The Challenge of Using CB-HSCs As Source for Gene Therapy: Lentiviral Vector Transduction, Phenotypic Characterization and Global Gene Expression Pro…
2015
Abstract Introduction: Genetic modification of autologous hematopoietic stem and progenitor cells (HSPC) is a promising clinical intervention to cure inherited monogenic diseases. Successful gene therapy trials have already been conducted using CD34+ cells from bone marrow and from mobilized peripheral blood. In this regard, cord blood (CB) represents an attractive source of HSCs due to its high concentration of high proliferative HSPC and increased susceptibility to be transduced by lentiviral vectors. Unfortunately, the major disadvantage is the limited number of HSC in the CB collection. Consequently, ex-vivo expansion of CB-HSC is desirable to extend clinical applications. Purposes: To …