fetal tissue implant or fetal cell therapy, implantation of tissue from a fetus into a patient. In experimental procedures, fetal brain tissue has been implanted in the brains of patients with Parkinson's disease so that the fetal tissue will supply chemicals lacking in the diseased brain, but such therapy failed to show significant benefits in a controlled study. Because fetal cell therapy uses tissue from freshly aborted fetuses, the procedure is controversial. Both the Reagan and G. H. W. Bush administrations banned the use of federal funds for fetal-tissue research that used tissue from aborted fetuses. President Clinton lifted the ban early in his administration. The successful transplantation of eggs from fetal ovaries in experiments with mice led to the suggestion in 1994 that human fetal ovaries or eggs taken from such ovaries could be implanted in infertile women, a possibility that troubled many ethicists and others. Some fear the use of what they call "fetal farming," the conception in vitro or in vivo of embryos solely for their medical usefulness. Others point to the potential benefits in the treatment of Alzheimer's and Huntington's diseases, and possibly in cases of nerve injury.

breast implant, saline- or silicone-filled prosthesis used after mastectomy as a part of the breast reconstruction process or used cosmetically to augment small breasts. An implant consists of a fluid-filled, malleable pouch that is designed to mimic to the look and feel of natural breast tissue when inserted into a pocket created under the skin in a procedure called a mammoplasty. After reports that leakage from silicone-filled implants might be causing autoimmune diseases (e.g., lupus, arthritis, scleroderma) in some women, the Food and Drug Administration in 1992 called for a moratorium on their use outside clinical trials. The ensuing scare resulted in the largest product liability settlement in U.S. history and the Chapter-11 bankruptcy of Dow Corning Corporation, one of the makers of the implants. Despite legal settlements in the billions of dollars, the claims against silicone-filled implants remain anecdotal; numerous scientific studies have found no link or only a weak equivocal link between the implants and disease. The use of silicone-filled implants was again approved by the FDA for reconstructive surgery in 1998 and for cosmetic surgery in 2006.