Teeth grown from single cells

Throw out the dentures Granny, ya gonna be able to get new teeth!

February 19, 2007 - JAPANESE researchers said yesterday they had grown normal-looking teeth from single cells in lab dishes, and transplanted them into mice.

They used primitive cells, not quite as early as stem cells, and injected them into a framework of collagen, the material that holds the body together. After growing them, they found their structures had matured into the components that make teeth, including dentin, enamel, dental pulp, blood vessels, and periodontal ligaments.

They were "arranged appropriately when compared with a natural tooth," the researchers reported in the journal Nature Methods. The teeth grew and developed normally when transplanted into a mouse, said Takashi Tsuji of the Tokyo University of Science in Chiba, Japan and colleagues.

They said their method was the first to show an entire organ could be replaced using just a few cells. "To restore the partial loss of organ function, stem cell transplantation therapies have been developed," they wrote.

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Science finding ways to regrow fingers
2/18/2007 — Researchers are trying to find ways to regrow fingers — and someday, even limbs — with tricks that sound like magic spells from a Harry Potter novel.

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.

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. And the lessons learned from studying regrowth of fingers and limbs could aid the larger field of regenerative medicine, perhaps someday helping people replace damaged parts of their hearts and spinal cords, and heal wounds and burns with new skin instead of scar.

But that's in the future. For now, consider the situation of Lee Spievack, a hobby-store salesman in Cincinnati, as he regarded his severed right middle finger one evening in August 2005. He had been helping a customer with an engine on a model airplane behind the shop. He knew the motor was risky because it required somebody to turn the prop backwards to make it run the right way.

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Granny says, "Brush yer teeth!"...

Brush your teeth to avoid heart attacks
September 11, 2008 - HERE's another reason to brush your teeth: poor dental hygiene boosts the risk of heart attacks and strokes, a pair of studies reported this week.

Heart disease is the No.1 killer worldwide, claiming upward of 17 million lives every year, according to the World Health Organisation. Smoking, obesity and high cholesterol are the most common culprits, but the new research shows that neglected gums can be added to the list. "We now recognise that bacterial infections are an independent risk factor for heart diseases,'' said Howard Jenkins of the University of Bristol in Britain, at a meeting of the Society for General Microbiology in Dublin.

"In other words, it doesn't matter how fit, slim or healthy you are, you're adding to your chances of getting heart disease by having bad teeth,'' the professor said. There are up to 700 different bacteria in the human mouth, and failing to scrub one's pearly whites helps those germs to flourish. Most are benign, and some are essential to good health. But a few can trigger a biological cascade leading to diseases of the arteries linked to heart attacks and stroke, according to the new research. "The mouth is probably the dirtiest place in the human body,'' Steve Kerrigan of the Royal College of Surgeons in Dublin said. "If you have an open blood vessel from bleeding gums, bacteria will gain entry to your bloodstream.''

Once inside the blood, certain bacteria stick onto cells called platelets, causing them to clot inside the vessel and thus decreasing blood flow to the heart. "We mimicked the pressure inside the blood vessels and in the heart, and demonstrated that bacteria use different mechanisms to cause platelets to clump together, allowing them to completely encase the bacteria,'' he said. This not only created conditions that can provoke heart attacks and strokes, it also shielded the bacteria from both, immune system cells and antibiotics. "These findings suggest why antibiotics do not always work in the treatment of infectious heart disease,'' Prof Jenkins said.

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