Cord blood, also known as placental blood, is the blood that remains in umbilical cord and placenta following a live birth. There are 3 sources of stem cells: umbilical cord blood, embryonic cells and bone marrow. Adult stem cells from bone marrow have limited uses while embryonic stem cell research is a major area of controversy. Umbilical cord blood stem cells are more proliferate and can be successfully substituted for embryonic stem cells in research and treatment.
Umbilical cord blood contains circulating stem/progenitor cells, and the cellular contents of umbilical cord blood are known to be quite distinct from those of bone marrow and adult peripheral blood. Over the past two decades, the presence and characteristics of hematopoietic stem cells in umbilical cord blood have been clarified. The frequency of umbilical cord blood hematopoietic stem/progenitor cells equals or exceeds that of bone marrow and greatly surpasses that of adult peripheral blood.
Compared with adult cells, umbilical cord blood hematopoietic stem cells produce larger hematopoietic colonies in vitro, have different growth factor requirements, are able to expand in long-term culture in vitro, and have longer telomeres. Umbilical cord blood transplantation for various hematopoietic reconstitutions and a lower incidence of graft-versus-host disease than expected with conventional therapies. Recently, it has been reported that umbilical cord blood contains mesenchymal progenitor cells capable of differentiating into marrow stroma, bone, cartilage, muscle, and connective tissues.
Furthermore, umbilical cord blood provides no ethical problems for basic suties and clinical applications. Umbilical cord blood cells can be collected without any harm to the newborn infant, and umbilical cord blood hematopoietic stem cell grafts can be cryopreserved and transplanted to a host after thawing without losing their repopulating ability. For these reasons, umbilical cord blood could be a prominent source of cells for transplantation in various diseases. It remains obscure, however, whether umbilical cord blood contains stem/progenitor cells leading to endodermal cells, including hepatocytes.
Moreover, in the cell-transplantation model into liver-injured severe combined immunodeficient mice, inoculated umbilical cord blood cells developed into functional hepatocytes in the liver, which released human albumin into the sera of the recipient mice. In conclusion, this study demonstrates that human umbilical cord blood is a source of transplantable hepatic progenitor cells. Our finding may have relevance to clinical application of umbilical cord blood derived cell transplantation as a novel therapeutic option for liver failure.
Umbilical cord blood is still in the early stages of use in scientific and medical research. Studying these cells will help researchers understand how they are able to transform into a wide array of more specialized cells that make up the human body. Some of the most serious medical conditions such as cancer and birth defects are caused by problems that occur somewhere in the cell process. A better understanding of how normal development occurs and disease processes can enable researchers to develop new and improved approaches to treating diseases and injuries.
0 comments:
Post a Comment