--Nadia S. Halim
--Nadia S. Halim
In the ongoing quest to chart the human body's storehouses of stem cells, a duo of dermatologists and their co-workers have identified progenitor cells in the "bulge" region of the hair follicle in mice that apparently give rise to both hair and epidermis (G. Taylor et al., "Involvement of follicular stem cells in forming not only the follicle but also the epidermis," Cell, 102:451-61, Aug. 18, 2000). In 1990, Robert M. Lavker, professor of dermatology at the University of Pennsylvania School of Medicine, and Tung-Tien Sun, professor of dermatology at the New York University School of Medicine, traced the progeny of bulge cells downward, where they give rise to the hair shaft. The observation that new skin in severely burned patients arises from surviving hair follicles led them to suspect that perhaps these "young transient amplifying cells" had another talent--regenerating the outer skin layer. ...