<P> In a bone marrow transplant, hematopoietic stem cells are removed from a person and infused into another person (allogenic) or into the same person at a later time (autologous). If the donor and recipient are compatible, these infused cells will then travel to the bone marrow and initiate blood cell production . Transplantation from one person to another is conducted for the treatment of severe bone marrow diseases, such as congenital defects, autoimmune diseases or malignancies . The patient's own marrow is first killed off with drugs or radiation, and then the new stem cells are introduced . Before radiation therapy or chemotherapy in cases of cancer, some of the patient's hematopoietic stem cells are sometimes harvested and later infused back when the therapy is finished to restore the immune system . </P> <P> Bone marrow stem cells can be induced to become neural cells to treat neurological illnesses, and can also potentially be used for the treatment of other illnesses, such as inflammatory bowel disease . In 2013, following a clinical trial, scientists proposed that bone marrow transplantation could be used to treat HIV in conjunction with antiretroviral drugs; however, it was later found that HIV remained in the bodies of the test subjects . </P> <P> The stem cells are typically harvested directly from the red marrow in the iliac crest, often under general anesthesia . The procedure is minimally invasive and does not require stitches afterwards . Depending on the donor's health and reaction to the procedure, the actual harvesting can be an outpatient procedure, or can require 1--2 days of recovery in the hospital . </P> <P> Another option is to administer certain drugs that stimulate the release of stem cells from the bone marrow into circulating blood . An intravenous catheter is inserted into the donor's arm, and the stem cells are then filtered out of the blood . This procedure is similar to that used in blood or platelet donation . In adults, bone marrow may also be taken from the sternum, while the tibia is often used when taking samples from infants . In newborns, stem cells may be retrieved from the umbilical cord . </P>

Where are developing red cells located in the bone marrow