Here’s something to smile about: a Japanese team has successfully grown replacement teeth and implanted them into the mouths of adult mice, suggesting that a similar technique could replace missing teeth in humans.

Takashi Tsuji at the Tokyo University of Science, Japan, and his colleagues took single-tooth mesenchymal and epithelial cells – the two cell types that develop into a tooth – from mouse embryos. They stimulated these cells to multiply before injecting them into a drop of collagen gel. Within days, the cells formed tooth buds – the early stage of normal tooth formation.

Full story. (via.)

Yes. Regrowable fingers too: Those superheroes just won’t stop.

There’s the guy who sliced off a fingertip but grew it back, after he treated the wound with an extract of pig bladder. And the scientists who grow extra arms on salamanders. And the laboratory mice with the eerie ability to heal themselves.

This summer, scientists are planning to see whether the powdered pig extract can help injured soldiers regrow parts of their fingers. And a large federally funded project is trying to unlock the secrets of how some animals regrow body parts so well, with hopes of applying the the lessons to humans.

Michael Ritter, an associate press science writer can almost smell the Pulitzer with this paragraph:

The implications for regrowing fingers go beyond the cosmetic. People who are missing all or most of their fingers, as from an explosion or a fire, often can’t pick things up, brush their teeth or button a button. If they could grow even a small stub, it could make a huge difference in their lives.

I see. I thought people who wanted their fingers were back were just selfish. Full story.