A person's blood could someday provide replacement cells for that individual's damaged brain or liver, a provocative study suggests. Human blood contains so-called stem cells that can be transformed outside the body into a variety of cell types, according to the report. This unexpected, and accidental, discovery may add a new element to the politicized debate over whether stem cells that persist in adults can match the therapeutic potential of stem cells derived from human embryos.
The possible new source of adult stem cells came to light when a coworker became ill and couldn't attend to petri dishes containing human blood cells called monocytes, says Eliezer Huberman of Argonne (Ill.) National Laboratory. In the body, these white blood cells migrate into tissues and mature into specialized immune cells, such as macrophages. Huberman's team has been studying the cellular signals behind th