National Geographic : 1991 Sep
Researchers need these clumps to study biological functions, trace gene mutations, and test new drugs. Alton Meister of Cornell University Medical College, for example, recently used a colony of human cells carrying the AIDS virus to show that a natural human molecule can actually suppress it. In May 1990 Solomon Snyder and Gabriele Ronnett (page 89), neuroscientists at Baltimore's Johns Hopkins University, announced they had grown human brain cells in the laboratory using cells from an 11-month-old girl who underwent brain surgery. This could lead to treatments for neurological diseases by allowing physicians to test possible drugs on these labora tory cells. "We were not involved in the child's care or in obtaining her parents' permission to use the tissue," Ronnett tells me. "We learned later that she died. I have a child the same age and would like to think I could show their courage." Human material also makes possible exploration that adds to the unknown. One example: Scientists believed that differ ent types of cells never "spoke" to one another. A new picture is emerging: Cells constantly manufacture and release chemical messengers- proteins called growth fac tors - that tell one another what to do. Nearly a hundred "I've gotten the quality of my life growth factors have been back," says Georgia school- discovered so far, each one a teacher Karen Petka, after bone Santa's bag of promises. transplants in both knees. Pic- "Osteoinductive factor," for tured with her daughter, Kari, example, induces new she adds gratefully, "I can take bone formation, and care of my family again." "epidermal growth fac tor" stimulates skin cells to heal much faster than is normally the case. Donations may also make it possible to find the causes of thousands of diseases -including muscular dystrophy, multiple sclerosis, and diabetes-many of them associated with gene defects. Such information often leads to screening, prevention, treatment, or cure. To find genes, researchers trace linkages and disease patterns within families. Some studies involve thousands of families; others try to go back five generations in a single family. Participating families, who rarely receive any direct benefit, often have "blood parties" during which they roll up their sleeves. Terrie Fargo of Banking on bones HROUGHOUT a person's lifetime specialized cells-osteoclasts, osteo blasts, and osteocytes-replace living bone with new bone tis sue. This natural process of regeneration allows the body to heal fractures or to accept grafts following the removal of dis eased bone. Grafts from a patient's own body heal faster, so are used whenever possible. But in those cases in which the patient has no "spare" parts, bone banks play a crucial role in acquiring, preserving, and sup plying vital bone for use in transplant operations.