11.   Gortex, a chemical sibling of Teflon, provides an inert mesh of porous scaffolding on which replacement bone cells can be grown in desired patterns.

12.   Growing the cells, scientists said, is a procedure done routinely in diagnostic laboratories and clinics, particularly in the Third World.

13.   He removes them from a patient and then grows the cells in culture.

14.   He said he worried about long-term effects, noting that normal cells become cancerous in a manner similar to the way these cells were grown in the laboratory.

15.   In May, Fred Gage from the Salk Institute in La Jolla, Calif., and colleagues announced that they had grown brain cells from cadavers.

16.   It then grows human cells in a culture to produce the drug.

17.   Now, researchers have learned how to grow progenitor cells in the laboratory so that they divide but do not differentiate.

18.   Often, the human cells are grown in the laboratory and then draped onto a fibrous, biodegradable scaffolding made in the shape of the desired tissue or organ.

19.   Okarma held out the prospect that one day, cells grown in petri dish cultures could be layered on to ailing hearts to restore their ability to pump blood.

20.   Other organs, like the skin, constantly grow new cells to replace old and damaged ones and still leave scars, Anversa said.