Scientists Build A Beating Heart

Researchers Say Beating Rat Heart Created From Scratch Could Aid In Preventing Organ Rejection

(AP)  Researchers seeking new treatments for heart disease managed to grow a rat heart in the lab and start it beating.

"While it still sounds like science fiction, we've hopefully opened a new door in the notion that we can build these tissues and one day provide options for patients with end-stage disease," said Dr. Doris Taylor, director of the Center for Cardiovascular Repair at the University of Minnesota. "We're not there yet, but at least now we have another tool in our tool belt."

Taylor led the team whose research appeared in Sunday's online edition of the journal Nature Medicine.

Scientists have worked for years for ways to grow body parts. Many efforts have focused on heart valves as an alternative to the plastic or animal valves that wear out after being implanted in humans.

An estimated 5 million people live with heart failure and about 550,000 new cases are diagnosed each year in the United States. Approximately 50,000 die annually waiting for a heart donor.

Taylor said in a telephone interview that her team began by trying to determine if it were possible to transplant rat heart cells. They took the hearts from eight newborn rats and removed all the cells. Left behind was a gelatin-like matrix shaped like a heart and containing conduits where the blood vessels had been. Scientists then injected cells back into this scaffold - muscle cells and endothelial cells, which line blood vessels.

The muscle cells covered the matrix walls and lined up together, while the endothelial cells found their way inside to coat the blood vessels, she said. Then the hearts were stimulated electrically.

"By two days we saw tiny, microscopic contractions, and by seven to eight days there were contractions large enough to see with the naked eye," she said. The tiny hearts could pump liquid at about one-fourth the rate of a normal fetal rat's heart.

"Obviously we have a long way to go," Taylor said. But the long-term hope, she said, is that a similar process could work with either human hearts from cadavers or pig hearts, with their cells stripped off and replaced by cells from the person needing a heart transplant to avoid rejection.

The next step is to take a pig heart, strip away the cells and repopulate it with cells from a pig to see if it will work in the larger heart.

Dr. John Mayer Jr., a heart specialist and researcher at Children's Hospital in Boston, said the report was an "important paper that advances the ball down the road." But, he added, "It's pretty long road."

Mayer, who was not part of Taylor's research team, noted that this was done in a small animal and it remains to be seen whether the same can be done in larger ones. He also wondered whether blood would flow freely, without clotting, through the reconstructed blood vessels.

"I think this is an important contribution, with more work to be done," Mayer said in a telephone interview.

In her research paper, Taylor also reports that the researchers are working on reseeding cells into other organs, including lungs, liver and kidneys.

The research was funded by the University of Minnesota and the Medtronic Foundation, the charitable arm of a medical company that makes heart devices such as stents and defibrillators.

[jimfinster]

ToolMangler:

Ya, likewise. Reasonable people can disagree reasonably :)

[toolmangler-2009]

I had forgotten that someone else on this planet ''thinks'' havent seen it in a while (grin)

[jimfinster]

Why? If I accept something on faith, that is up to me. I have not taken anything from you, have I? If you wish to accept on Faith, that is up to you. I can do nothing for you but tell ''''MY'''' truth.
Posted by ToolMangler

I am fine with that. But be careful not to confuse faith with fact. They might or might not be the same. That is the only point I was trying to make...

It does me no injury for my neighbor to say there are 20 gods, or no God. It neither picks my pocket nor breaks my leg. -- Thomas Jefferson

[toolmangler-2009]

You can''''t claim definitive knowledge without definitive proof.
Posted by jimfinster at 06:41 PM : Jan 14, 2008


Why? If I accept something on faith, that is up to me. I have not taken anything from you, have I? If you wish to accept on Faith, that is up to you. I can do nothing for you but tell ''MY'' truth.

[toolmangler-2009]

Posted by jimfinster at 06:43 PM : Jan 14, 2008


Here is the difference, The point I make is "I believe what I say" for me that is sufficient. If you wish you may accept that or search it out in your own way. If you say the the " Flying Spaghetti Monster" Is your GOD, I as a thinking person must now decide if your words have credence. That puts the pressure on me. The only thing that now affects you is "did you lie or not" (you can see where this will go, so I won''t belabor it.)

[jimfinster]

For example, I can claim that the Flying Spaghetti Monster controls the universe. I am free to make that claim. But clearly no one should believe me if I can''t support the claim with verifiable facts.

Not an attack on you by any means.

[jimfinster]

t requires no proof from me at all, I do not claim ownership or control of GOD, Were I selling (whatever)then I could be required to furnish some proof. The only thing I have done in my words is to show ''''my belief'''' through the conveyance of my words. You are entirely welcome to demand proof, but not from me. I do not ''''own'''' GOD, I belong to him. All I can tell you is ''''my'''' experience with GOD, nothing else.
Posted by ToolMangler

If you claim it, you must proof it. You can''t claim definitive knowledge without definitive proof.

[toolmangler-2009]

Descartes said "I think therfore ''I'' am!" This for him is a correct statement. All I can say is thats good for you, but what about ''me''. does your state of being define me, or merely suggest me? Each one of us (humans) must come to some agreement within himself that he exists, (because of a preponderance of evidence) or fail to accept it and curl into a ''fetal'' ball and die. By the same token, our perception of GOD is an inward thing that must be searched out and agreed on or rejected whereupon we die ''inwardly at first then outwardly'' near the end.

[toolmangler-2009]

Saying there is a God is extraordinary claim. And extraordinary claims require extraordinary proof.
Posted by jimfinster at 06:14 PM : Jan 14, 2008



It requires no proof from me at all, I do not claim ownership or control of GOD, Were I selling (whatever)then I could be required to furnish some proof. The only thing I have done in my words is to show ''my belief'' through the conveyance of my words. You are entirely welcome to demand proof, but not from me. I do not ''own'' GOD, I belong to him. All I can tell you is ''my'' experience with GOD, nothing else.

[jimfinster]

ToolMangler:

As Michael Shermer might say, I am a militant agnostic :)

That means "I don''t know and you don''t either!" If someone claims to know, my response is "prove it". Saying there is a God is extraordinary claim. And extraordinary claims require extraordinary proof.