Guest guest Posted March 6, 2002 Report Share Posted March 6, 2002 http://www.chron.com/cs/CDA/story.hts/front/1285017 -- " I'll lean on you and you lean on me and we'll be okay. " Dave s HoustonChronicle.com Pick a section Home Page Business Classifieds Columnists Comics Community Directory Entertainment Features Health Help Inside Story Marketplace Metropolitan Page 1 News Search Archives Site Map Space Sports Travel Weather Section: Front page Section: Local State Current stories in this section: Enron seeks extension to become profitable decries Israel's declaration of war Stem cells in bloodstream can grow into tissue Report: Deficits larger than Bush estimates Printer-friendly format March 6, 2002, 9:43PM Stem cells in bloodstream can grow into organ tissue M.D. finding may affect disease treatment By TODD ACKERMAN Copyright 2002 Houston Chronicle Medical Writer AP Human embryonic stem cell colonies in different stages of development. Researchers at the University of Texas M.D. Cancer Center have shown that stem cells that circulate in the bloodstream are capable of growing into liver, gut and skin tissue. The discovery suggests circulating stem cells play an active role in replacing normal tissue or repairing injured organ tissue -- and thus one day could be used to treat disease, the researchers said. "This discovery leads us into new knowledge of what happens in the body without intervention," said Dr. Zeev Estrov, a professor of bioimmunotherapy and one of the study's principal investigators. "If peripheral blood stem cells are capable of differentiating into many different organs, this may affect the treatment of many diseases." The study, published in today's New England Journal of Medicine, is the latest finding suggesting adult stem cells may share some of the properties that make embryonic stem cells a great hope as medicine's next frontier. While embryonic stem cells grow into any sort of tissue the body needs, adult stem cells were long thought to make only one kind of cell, depending on their location. The dogma was upset in 2001, when researchers reported adult stem cells in the bone marrow grew into skin, lung and gastrointestinal tissues. M.D. researchers noted that stem cells in the blood represent a major advance because, compared with bone marrow stem cells, they are more plentiful and can be easily collected from the blood by a routine blood-banking procedure. The two types of stem cells are virtually identical. The idea for the M.D. research came from two independent clinical studies that recently reported donor-derived liver cells were found in patients who had received bone marrow transplants. Since the bone marrow was not in direct physical contact with the liver, gastrointestinal tract or skin, M.D. researchers hypothesized that the circulating blood might be the "vehicle" that contains and distributes stem cells capable of morphing into various organ cells. So the M.D. researchers examined tissue collected from 12 cancer patients after stem cell transplants. They found evidence the stem cells manufactured new tissue in unlikely places within two weeks -- of the six women who got transplants from a brother, cells with a male chromosome accounted for up to 7 percent of tissue samples taken from the liver, gastrointestinal tract and skin. Estrov said the team's next step will be to learn the trigger mechanisms that reprogram circulating stem cells to become various organ cells, and then to take them out and try to reprogram them. He said potential trigger mechanisms include tissue damage from high-dose radiation or chemotherapy and when the immune system attacks organs following transplantation. There have been numerous other studies suggesting nonembryonic stem cells -- in animals and human umbilical cords, for instance -- have greater flexibility than previously thought. But M.D. researchers stopped short of saying their discovery represents a future treatment source free of the controversy that has surrounded fetal and embryonic tissue. "We don't know yet whether these adult blood stem cells have properties that are similar to embryonic stem cells," said Dr. Korbling, a professor of blood and marrow transplantation and the lead author of the paper. "There is no comparative study. But our findings constitute the first clinical evidence that circulating donor-derived stem cells generate organ-specific cells in humans." Return to top Point to the Advertiser's Logo for more options. Oil Changes, Tune-ups, Tires, and a Whole Lot More! Did You Take Fen-Phen? Explore Galveston. Click Here. Used Office Furniture-click Here For Details! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.