Stem cells grow replacement joints in rabbits

CBC News

From: http://www.cbc.ca/

Rabbits were able to regrow a leg joint using their own stem cells, say scientists exploring the cells' potential to replace artificial joints in human patients.

Researchers removed the forelimb thigh joint from 10 rabbits and then coaxed the animals' stem cells to regenerate the bone and cartilage .

It’s the first time an entire joint surface has been regenerated with return of functions including weight bearing and locomotion, said study author Professor Jeremy Mao of Columbia University Medical Center in New York.

The experiment is described in Thursday's online issue of the journal The Lancet.

For the study, Mao and his colleagues removed the limbs from 10 rabbits that then received an artificial limb-shaped skeleton soaked in growth factors to attract bone and cartilage stem cells.

Another 10 rabbits received the limb implant without the growth factor, known as growth factor beta-3, but they were not able to move as well as the animals in the first group, the researchers reported.

Three other rabbits whose joints were surgically damaged and not repaired had a permanent limp.

The findings represent a proof of principle for patients who need a knee, shoulder, hip or knee joint regenerated, the researchers said, noting that scientific and regulatory issues remain.

Bioreactor 'renaissance'

Human patients may also have other conditions and medications that could affect the regeneration of their joints, which the animal models did not face.

Since humans use two legs rather than four like rabbits, people might need to be on bed rest for longer periods than the animals.

In a journal editorial accompanying the study, Dr. Patrick Warnke, a stem cell researcher and plastic surgeon at Bond University in Gold Coast, Australia, described the work as "a renaissance of use of the host as a bioreactor."

But he added not all patients would be able to regenerate tissues the same way, such as elderly people with diabetes who might benefit from standard metal joint replacement.

The recovery period of immobility while the joint regenerates would also be risky, Warnke said.

Warnke suggested cultivating the joint replacement inside a patient's muscle joint and then transplanting it to where needed to reduce regeneration time.

Metal joints last about 10 to 15 years. Demand for replacement joints is expected to grow as the population ages.

The study was funded by New York State Stem Cell Science and the U.S. National Institutes of Health.

Stockholm's rabbits burned to keep Sweden heated

The bodies of thousands of wild rabbits culled each year from Stockholm's parks are being used to fuel a heating plant in central Sweden.

By Allan Hall

Six thousand bunnies were killed last year Photo: GETTY IMAGES

Animal rights activists have claimed that domestic pets are also being rounded up and incinerated.

"Those who support the culling of rabbits think it's good to use the bodies for a good cause. But it feels like the power company is trying to turn the animals into an industry rather than look at the main problem," said Anna Johannesson of the Society for the Protection of Wild Rabbits.

The rabbits going up in smoke are the inhabitants of Stockholm's parks who are culled to protect the shrubs and trees on which they gorge. But many of them are tame domestic pets turned loose by owners who no longer want them.

Six thousand bunnies were killed last year. The corpses were frozen and then sent to a special heating plant at Karlskoga, in central Sweden, where the cadavers were burnt in order to help heat the homes of residents of Värmland.

But animal rights activists have called for better treatment for the wild rabbits.

Mrs. Johannesson told local newspaper Vart Kungsholmen; "We want to see them start looking at other solutions for the rabbits. Helsinki in Finland sprays the plants to make them unappetizing and they have also set up a system of shelters for animals to be donated to. They have come much further along than us."ra

Easter Gifts, Multiplying on the Loose

Karena Cawthon for The New York Times

The rabbit population is booming on Okaloosa Island, Fla., and some have been hanging out in the backyard of Phil and Shirley Dykes, left. Trapping has begun.

By DAMIEN CAVE

Published: April 17, 2009

OKALOOSA ISLAND, Fla. — What is it about Florida that inspires pet owners to set their captives free?

Green iguanas released decades ago now splash in the pools of Palm Beach. Peacocks roam free in parts of Miami, Burmese pythons are spreading through the entire state — and here, on this two-mile shoelace of beachfront land, the bunny problem keeps multiplying.

Dozens of rabbits, the spawn of Easter gifts from as far back as 2002, now run wild in a field of two-story condominiums.

Actually, wild is an exaggeration. “I have two that let me pet them,” said Denise Callahan, 55, out for a walk on Wednesday with her dog, Gigi. “One’s Peter; the other’s Mama.”

A few feet to her right, a snow-white rabbit with dark eyes sniffed the sand near a boat trailer. Behind her, a chubby brown one hopped past a parked Hyundai. Clearly, in a neighborhood of mostly parking lots and small apartments, these bunnies felt at home.

John Wagnon, 45, a bartender working on a bicycle in his garage, said they often cheered him up. “Some days,” he said, “you have a bad day at work, you turn the corner and you say, ‘Bunnies!’ ”

He pointed excitedly, mimicking his usual reaction. “It’s like the homeless situation,” he said. “Where else would they want to live?”

Next door, Russell Beasley just shook his head. He had been building cabinets in his garage when he felt compelled to offer an opinion. “They’re a pain,” he said, revealing a Massachusetts accent. Antibunny bile followed: He compared them to rats; he said they would attract snakes; he said they would cause car accidents because drivers would swerve to miss them. “People might think they’re cute, but they’re a menace,” said Mr. Beasley, 61. “They’re multiplying like crazy — that’s what they do.”

Previous cases of unintended fertility in Florida have led government officials to step in. State rules that took effect last year force anyone who buys a python to purchase a $100 annual permit, and the slithery reptile gets a mandatory microchip that would let officials track the animal back to its owner.

Palm Beach County Commissioners have pushed for the same policy to deal with its leathery iguanas.

Here in Okaloosa Island, the solution has been a little more old-school: wire traps with carrots as bait. The local animal shelter put them out after Easter this year, and the first rabbit was caught on Wednesday, in the front yard of Phil and Shirley Dykes. Their little patch of green had already become ground zero for all things bunny because they lacked a dog and provided a delicacy — healthy rose bushes.

Even with a large, confused brown rabbit in the cage, a half dozen others sat nearby, including a black, furry baby that would fit in a child’s hand. “This is an animal friendly environment,” said Mr. Dykes, 68, a retired engineer who once worked for NASA.

Standing on his front porch, he admitted that his wife had to convince him to host the trap. His soft spot for animals was well-known; recently he let a group of doves nest in his garage. He even left the door partly open so they could come and go as they pleased.

The rabbits initially received the same warm welcome.

“It’s amusing to watch them play in the yard,” he said, adding, “I didn’t mind them until they ate the shrubbery.”

His wife was less generous. “I just had three in the garage, and one came right up to me,” she said. “No thank you.”

Mr. Dykes insisted, however, that they not be killed — a common request here that previously kept the Panhandle Animal Welfare Society at bay. Dee Thompson, director of animal control at the agency, said a solution emerged only in the last few days: a man with lot of land in Walton County volunteered to take them after seeing an article about them in The Northwest Florida Daily News.

“He already has rabbits on his property,” Ms. Thompson said. “He said he wouldn’t eat them.”

Residents here are likely to miss the bunnies if too many disappear. Cassandra Higgins, 25, said they did not cause much harm, and even her dogs, Lady and Rugar, seemed to like them.

When told about the traps, Ms. Callahan said, “Oh no.” Come to think of it, she said she had not seen Mama — “a huge brown rabbit with scars all over her like she’d been through the mill” — in days. And as she walked Gigi down the road during a gorgeous coastal sunset, she turned around with a final call to action.

“Save the rabbits!” she said, laughing, knowing it sounded a bit ridiculous. “Save the rabbits!”