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Stem Cell Sources (stem + cell_source)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Early bacteremia in pediatric hematopoietic stem cell transplant patients on oral antibiotic prophylaxis

PEDIATRIC BLOOD & CANCER, Issue 2 2005
Leslie S. Kersun MD, MSCE
Abstract Background Bacteremia occurs during hematopoietic stem cell transplant (HSCT) in 20%,25% of patients and the use of gut decontamination (GD) to decrease this risk is controversial. Our purpose was to determine the incidence of bacteremia and antimicrobial resistance post-HSCT in pediatric patients receiving GD, and to identify risk factors associated with infection. Procedures This was a retrospective cohort study of 182 pediatric patients undergoing first HSCT for malignant disease at The Children's Hospital of Philadelphia from January, 1999 to December, 2002. We examined the impact of age, sex, race, diagnosis, disease status, conditioning regimen, recent bacteremia, stem cell source, donor, graft versus host disease prophylaxis agents, and mucositis severity using Cox proportional hazard models. GD consisted of amoxicillin (azithromycin, if penicillin allergic) and oral gentamicin. Outcome was first episode of bacteremia prior to absolute neutrophil count (ANC) 500/mm3. Antibiotic susceptibilities were performed on all isolates. Results Seventy-four patients (41%) developed bacteremia. The majority were Gram-positive cocci, with Staphylococcal (50%) and Streptococcal species (28%) the most common. Gram-negative organisms were identified in 22% with Pseudomonas (5.7%) and Klebsiella species (3.4%) the most common. Of the Streptococcal infections, 72% were resistant to ampicillin; only 25% of the Gram-negative bacteria were resistant to gentamicin. Race was the only factor associated with early bacteremia (hazard ratio 2.3 for non-Caucasian, non-African-American patients, CI 1.3,4.3, P,=,0.007) Conclusions Early bacteremia is common after HSCT, despite the use of GD. Resistant Gram-positive organisms predominate, consistent with recent trends in immunocompromised patients. Although used in practice, there is no clear evidence for the efficacy of GD and this study provides the basis upon which to develop a randomized clinical trial evaluating the current GD regimen with placebo. © 2004 Wiley-Liss, Inc. [source]

Alternative haematopoietic stem cell sources for transplantation: place of umbilical cord blood

BRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2009
Angela R. Smith
Summary Umbilical cord blood has rapidly become a valuable alternative stem cell source for allogeneic haematopoietic stem cell transplantation. Extensive research over the last 20 years has established the safety and efficacy of umbilical cord blood transplantation in both children and adults with a variety of malignant and non-malignant diseases. This research has clearly shown that this stem cell source has several unique characteristics resulting in distinct advantages and disadvantages when compared to transplantation with unrelated bone marrow or peripheral blood stem cells. This article reviews the most recent literature comparing the outcomes after umbilical cord blood transplantation with other alternative stem cell sources. [source]

Glucose-responsive insulin-producing cells from stem cells

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2002
David J. Kaczorowski
Abstract Recent success with immunosuppression following islet cell transplantation offers hope that a cell transplantation treatment for type 1 (juvenile) diabetes may be possible if sufficient quantities of safe and effective cells can be produced. For the treatment of type 1 diabetes, the two therapeutically essential functions are the ability to monitor blood glucose levels and the production of corresponding and sufficient levels of mature insulin to maintain glycemic control. Stem cells can replicate themselves and produce cells that take on more specialized functions. If a source of stem cells capable of yielding glucose-responsive insulin-producing (GRIP) cells can be identified, then transplantation-based treatment for type 1 diabetes may become widely available. Currently, stem cells from embryonic and adult sources are being investigated for their ability to proliferate and differentiate into cells with GRIP function. Human embryonic pluripotent stem cells, commonly referred to as embryonic stem (ES) cells and embryonic germ (EG) cells, have received significant attention owing to their broad capacity to differentiate and ability to proliferate well in culture. Their application to diabetes research is of particular promise, as it has been demonstrated that mouse ES cells are capable of producing cells able to normalize glucose levels of diabetic mice, and human ES cells can differentiate into cells capable of insulin production. Cells with GRIP function have also been derived from stem cells residing in adult organisms, here referred to as endogenous stem cell sources. Independent of source, stem cells capable of producing cells with GRIP function may provide a widely available cell transplantation treatment for type 1 diabetes. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Stem cells and diabetes treatment,

APMIS, Issue 11-12 2005
OLE DRAGSBÆK MADSEN
Diabetes mellitus types 1 and 2 are characterized by absolute versus relative lack of insulin-producing , cells, respectively. Reconstitution of a functional ,-cell mass by cell therapy , using organ donor islets of Langerhans , has been demonstrated to restore euglycaemia in the absence of insulin treatment. This remarkable achievement has stimulated the search for appropriate stem cell sources from which adequate expansion and maturation of therapeutic , cells can be achieved. This recent activity is reviewed and presented with particular focus on directed differentiation from pluripotent embryonic stem cells (versus other stem/progenitor cell sources) based on knowledge from pancreatic ,-cell development and the parallel approach to controlling endogenous ,-cell neogenesis. [source]