Embryonic Stem Cells Debut Amid Little Media Attention

STARTING POINT: Johns Hopkins' John Gearhart announced at a July meeting that he and a colleague had cultured human embryonic stem cells.

Last July, with repercussions from Scottish sheep clone Dolly yet to die down, came news of potentially even greater importance. At the 13th International Congress of Developmental Biology in Snowbird, Utah, held the week of July 12, John Gearhart, a professor of gynecology and obstetrics at Johns Hopkins University School of Medicine in Baltimore, reported that he and postdoctoral fellow Michael Shamblott for seven months had cultured human embryonic stem (ES) cells. Such cells theoretically can divide and become virtually any cell type-bone or muscle, nerve or fibroblast, for example. That suggests intriguing applications, including a new tool to view development and even made-to-order human replacement parts.

Developmental biologists, familiar with the central role of ES cells in making "knockout" mice, envisioned the ability to nurture human tissues...