Lab-grown bladders prove a success in dogs.Foreshadowing fore·shad·ow
tr.v. fore·shad·owed, fore·shad·ow·ing, fore·shad·ows
To present an indication or a suggestion of beforehand; presage.
fore·shad a time when a patient's own cells may be harvested, multiplied, and fashioned into a replacement organ, researchers in Boston have successfully transplanted laboratory-grown bladders into six beagles.
"This is the first demonstration that you can engineer a complete organ and replace the native organ with [it]," says David J David J. Haskins (b. April 24, 1957, in Northampton, England) is a British alternative rock musician. He was the bassist for the seminal gothic rock band Bauhaus. Life and work . Mooney of the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. in Ann Arbor Ann Arbor, city (1990 pop. 109,592), seat of Washtenaw co., S Mich., on the Huron River; inc. 1851. It is a research and educational center, with a large number of government and industrial research and development firms, many in high-technology fields such as , who is attempting to grow artificial livers.
For a century, physicians have replaced diseased or damaged bladders by removing sections of a person's intestines and shaping them into a substitute bladder. While the procedure offers some relief to patients, complications often develop because nature designed intestinal tissue for a purpose--absorbing nutrients--other than holding urine. "You start absorbing stuff that should be excreted," says Anthony Atala Anthony Atala, M.D., is the Director of the Wake Forest Institute for Regenerative Medicine, and Chair of the Department of Urology at the Wake Forest University School of Medicine in the state of North Carolina in the United States. of the Children's Hospital A children's hospital is a hospital which offers its services exclusively to children. The number of children's hospitals proliferated in the 20th century, as pediatric medical and surgical specialties separated from internal medicine and adult surgical specialties. in Boston.
Other physicians have turned to human-made materials to create artificial bladders, but those efforts have also run into problems. Consequently, to build a better bladder, Atala and his colleagues decided to employ the organ's own cells.
The bladder is essentially a hollow vessel with an outer layer of muscle cells and an inner lining of urothelial cells, which form an impermeable impermeable /im·per·me·a·ble/ (-per´me-ah-b'l) not permitting passage, as of fluid.
Impossible to permeate; not permitting passage. reservoir for urine. While bladder-muscle cells grow readily in the laboratory, urothelial cells have frustrated scientists for many years.
"The big step forward was finding the right soup--the right combination of growth factors--that would make these cells grow," says Atala. Indeed, he and his colleagues can now take a bladder sample no larger than a postage stamp postage stamp, government stamp affixed to mail to indicate payment of postage. The term includes stamps printed or embossed on postcards and envelopes as well as the adhesive labels. and, within 6 weeks, grow enough urothelial cells to cover a football field.
To turn the cells into an organ, the researchers first mold biodegradable plastic into a bladder-shaped shell. They then coat the outside with layers of muscle cells and the inside with urothelial cells.
To test this strategy, Atala's group procured bladder tissue from beagles and grew it into organs. After removing the dogs' bladders, the investigators implanted the artificial ones derived from the beagles' own cells. Within a month, the organs began to perform like normal bladders, the researchers report in the February NATURE BIOTECHNOLOGY.
Within 3 months, the plastic shells had degraded, and the transplanted organs were hard to distinguish from natural ones. Blood vessels Blood vessels
Tubular channels for blood transport, of which there are three principal types: arteries, capillaries, and veins. Only the larger arteries and veins in the body bear distinct names. quickly grew into them. Moreover, nerves seem to form proper connections with the new organs, allowing the dogs to regain normal control of their bladders. Some dogs have had the artificial bladders for nearly a year without any problems.
The beagles' recovery of bladder control was a pleasant surprise for Atala, who had expected that any dog receiving the artificial organ would need a catheter to drain away urine buildup. People with bladders made from intestinal tissue must use such catheters, he notes.
The new artificial bladders may prove useful for the many thousands of people whose own organ has been ravaged rav·age
v. rav·aged, rav·ag·ing, rav·ages
1. To bring heavy destruction on; devastate: A tornado ravaged the town.
2. by cancer or damaged by an infection or injury. Even people born with defective bladders might have a healthy one grown from their own cells, says Atala.
While the bladders of dogs closely resemble those of people, Atala cautions that more testing of this transplant strategy must occur before artificial bladders are ready for the clinic. "If you're a dog with a bladder problem, you may be set, but it's always a significant challenge to translate things you can do in an animal model to things you can do in people," agrees Mooney.