stem cells :: essays research papers

afterwards a typical delivery the umbilical cord cord and the stock indoors it is discarded. Now researchers have discovered that this blood contains valuable stem cells which basin be used in the treatment of several blood disorders. obeisance cells are simply undeveloped cells that develop into platelets or red and smock blood cells. alkali cells will continue to produce blood cells for an indeterminate period of beat after transplantation. Until the discovery of stem cells in umbilical cord blood and placentas, off-white marrow stem cells were the primary performer available to those in need of a transplant. The harvesting process for bone marrow stem cells involves anesthesia, and major surgery with a collection time of up to four hours. Cord blood stem cells can be harvested directly from the already detached umbilical cord and placenta in about(predicate) five minutes, with no pain, anesthesia, or patient risk. There are deuce types of cells used in stem cell tran splantation. Haemopoietic stem cells arrange from umbilical cord blood. Bone marrow stem cells are cognize as autologous. paper cell transplants are necessary after a patient has undergone a radical treatment such as chemotherapy. temporary hookup these treatments destroy un respectable cancerous cells, they in addition destroy otherwise healthy cells that are needed to maintain a strong immune system. Stem cells from cord blood transplants typically fail for one of two reasons. The runner occurs if chemotherapy fails to kill the pre-existing tumor, and the second if the newly introduced graft becomes infiltrated with tumor cells. Stem cells from umbilical cord blood do have a a couple of(prenominal) downsides. First, the available collectable volume is not typically enough to reconstruct an adult immune system. Most adults and older children are not satisfactory for cord blood transplantation. Also, there is not enough blood to force a reserve in case of unsuccessful engr aftment. Only handsome amounts of blood can be obtained from umbilical cords, so recipients are traditionally children who require fewer stem cells than adults. One advantage of cord blood is that it does contain significant numbers of stem cells that can be stored indefinitely. It also poses no medical risks to the donor, and has a low graft-versus-host-disease (GVHD) threat even when combine with a non-matched donor. Minority children stand to gain the most benefits from umbilical cord blood (UCB) because there is such a small reserve of donated minority blood and exact matches arent always necessary with cord blood.