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Research may lead to baldness remedies

WASHINGTON -- Mice with deep skin wounds can grow new hair, scientists said yesterday in a finding that offers hope for a baldness remedy for humans.

The mice regenerated hair at the site of the wound via molecular processes similar to those used in embryonic development, according to the research, published in the journal Nature.

The findings show mammals possess greater regenerative abilities than commonly believed. While some amphibians can regenerate limbs and some reptiles can regenerate tails, regeneration in mammals is far more limited.

Dr. George Cotsarelis, a dermatology professor at the University of Pennsylvania School of Medicine in Philadelphia who led the study, said the findings dispel the dogma that hair loss is permanent in people and other mammals.

Cotsarelis said the findings could pave the way for remedies for male-pattern baldness and other types of hair loss. He said the idea would be to apply compounds to get epidermal cells to turn into hair follicles.

The regenerated follicles functioned normally, cycling through the various stages of hair growth, and the hair was indistinguishable from neighboring hair with a key exception -- it lacked pigmentation and was white.

The otherwise brown-haired mice had patches of white hair marking the site of the wound.

Cotsarelis said the white-hair issue may not materialize in any baldness remedy in people because the human pigmentation system differs from that in mice.

The researchers also found a way to amplify the natural regeneration process, causing mice to grow twice as many new hairs by giving the skin a specific molecular signal.

Cotsarelis said it probably would be more than five years before a treatment for baldness was possible.