Stem cell potentiation

Despite many unresolved issues related to treatment dose, timing, and delivery, the clinical potential of stem cell therapy for cardiovascular disease is enormous. The expectations of both patients and clinicians for this new therapeutic modality, however, are high and to achieve the full potential stem cell therapy has to offer will require continued cooperation and future close collaboration between basic and clinical scientists. 

Non-Hodgkin s lymphomas are further classified as lymphocytic or histiocytic. Lymphocytic lymphomas may be poorly differentiated (according to the extent to which they have evolved from the pluri potential stem cell) they may also be nodular (concentrated) or diffuse. 

Growth of multi-potential stem cells, myeloid, erythroid, mast cells Increases MHC Class II expression on macrophages, promotes mast cell proliferation, promotes hematopoietic precursors, isotype switching in IgGl and IgE, T cell proliferation, activation of B cells from resting state, increased MHC Class II expression, proliferation in presence of Ag, increased IL-2R receptor expression... 

The potential for improved radioprotection by combining Tempol with growth factors such as stem cell factor (SGP), which protects by quite different mechanisms, has been examined in mice (82). Both SGP alone, given 20 and 4 h before and 4 h after TBI, and Tempol alone, given 10 min before TBI, increased 30-day survival, but protection was greater than additive when the two agents were combined. 

For patients with leukemia, the transfer of siRNA-based strategies into clinical applicability will certainly be both frustrating and time-consuming and many hurdles still have to be overcome in order to realize the therapeutic potential of siRNAs. Efficient delivery of siRNA into the leukemic stem cell and their unknown influence of the patient s immune system are the most challenging issues that need to be addressed. 

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potential cure for SCD. The best candidates are children with SCD who are younger than 16 years of age with severe complications who have an identical H LA-matched donor, usually a sibling. The transplant-related mortality rate is between 5% and 10%, and graft rejection is approximately 10%. Other risks include secondary malignancies, development of seizures or intracranial bleeding, and infection in the immediate posttransplant period.6,25,32,33... 

In HSCT, very high doses of chemotherapy with or without total-body radiation (TBI) are given in an attempt to potentiate leukemia cell kill. Hematopoiesis is restored by the infusion of stem cells harvested from an HLA-compatible donor, thereby rescuing the patient from the consequences of total aplasia.13 It is the most effective antileukemic therapy currently available. 

Molineux G, Pojda Z, Hampson IN, Lord BI, Dexter TM. Transplantation potential of peripheral blood stem cells induced by granulocyte colony-stimulating factor. 

Pittenger MF et al (1999) Multilineage potential of adult human mesenchymal stem cells. Science 284(5411) 143-147... 

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