title: Recent advances in hematopoietic stem cell biology.
abstract: OBJECTIVE
  Exciting advances have been made in the field of hematopoietic stem cell biology during the past year. This review summarizes recent progress in the identification, culture, and in vivo tracking of hematopoietic stem cells.
  
  
  RESULTS
  The roles of Wnt and Notch proteins in regulating stem cell renewal in the microenvironment, and how these molecules can be exploited in ex vivo stem cell culture, are reviewed. The importance of identification of stem cells using functional as well as phenotypic markers is discussed. The novel field of nanotechnology is then discussed in the context of stem cell tracking in vivo. This review concludes with a section on the unexpected potential of bone marrow-derived stem cells to contribute to the repair of damaged tissues. The contribution of cell fusion to explain the latter phenomenon is discussed.
  
  
  CONCLUSIONS
  Because of exciting discoveries made recently in the field of stem cell biology, researchers now have improved tools to define novel populations of stem cells, examine them ex vivo using conditions that promote self-renewal, track them into recipients, and determine whether they can contribute to the repair of damaged tissues. These discoveries will significantly advance the field of stem cell transplantation.
authors.affiliation: Department of Internal Medicine, Division of Oncology, Hematopoietic Development and Malignancy Program, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Jesper
authors.initials: J
authors.lastname: Bonde
authors.forename: David A
authors.initials: DA
authors.lastname: Hess
authors.forename: Jan A
authors.initials: JA
authors.lastname: Nolta
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D018929:Cell Culture Techniques; D002469:Cell Separation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051880:Receptors, Notch; D033581:Stem Cell Transplantation; D051153:Wnt Proteins
chemical_list: D015415:Biomarkers; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051880:Receptors, Notch; D051153:Wnt Proteins