Fat Cells for Broken Hearts

A company is testing whether stem cells from fat could help prevent long-term damage after a heart attack.

Too much fat around the waist may be bad for your health, but the stem cells it contains might one day save your life. Starting this month, a new European trial aims to determine whether stem cells harvested from a person's own fat, delivered shortly after a heart attack, could prevent some of the cardiac muscle damage that results from blocked arteries.

During a heart attack, blood vessels that deliver blood to the heart muscle are blocked, and the lack of oxygen slowly kills the tissue. San Diego-based Cytoryi Therapeutics has developed a treatment that aims to prevent much of that muscle damage before it starts. It works by injecting a concentrated slurry of stem cells and other regenerative cells isolated from the patient's body directly into the heart's main artery within 24 hours after an attack. "Time is muscle. The quicker you get in, the better," says Christopher Calhoun, Cytori's chief executive officer. "You can't do anything about dead tissue, but tissue that's bruised and damaged—that's revitalizable. If you can get new blood flow in there, that tissue comes back to life."

Adult stem cells, which exist in small populations throughout the body, can differentiate to form specific tissue types and are responsible for repairing injuries and replacing dying cells. The prospect of using them to heal damaged heart muscle has tantalized biomedical researchers for more than two decades. If the stem cells come from a patient's own body, there is no risk of rejection. A number of clinical trials in recent years have focused on using stem cells collected from bone marrow, since this potent population can differentiate into both cardiac muscle cells and blood vessel cells, among other types. But marrow stem cells are difficult to collect and somewhat scarce; they must be isolated and then grown in culture before they're injected back into an injured heart. The process can take weeks.

Cytori has created a portable machine that, in less than an hour, can reduce a sample of fat "about the size of a can of Coke," Calhoun says, to less than a teaspoon of concentrated slurry that Cytori believes contains its most vital elements: stem cells, smooth muscle cells, cells that line blood vessels, and a number of other regenerative cells that can promote growth healing.

Cytori began a large-scale trial this month and hopes to test the procedure on 360 patients. The company aims to start large-scale clinical trials on heart attack patients in the United States by 2014 and on patients with chronic heart failure even earlier than that.

But it's still early. Clinical trials of stem cells derived from bone marrow have shown mixed results in treating heart disease, and it's unclear whether fat-derived cells will fare better. "If it works, it would be wonderful to have a ready-made source of autologous stem cells," says Richard Schatz, research director of cardiovascular interventions at Scripps Health in San Diego, one of the inventors of the coronary stent. But he and others note that it will take many more trials to determine how effective Cytori's methods are compared with treatments based on marrow stem cells.

Woman Born With Half a Brain is Living a Full Life.

Michelle Mack has turned medical thinking upside down.

The right side of Michelle Mack's brain rewired itself to take over functions controlled by the left.

Born with only half a brain, Mack can speak normally, graduated from high school and has an uncanny knack for dates.

At 27, doctors determined that the right side of her brain had essentially rewired itself to make up for function that was likely lost during pre-birth stroke. But her childhood and young adult years were fraught with frustration.

"It was very hard for me" Mack said. "It was very hard for me growing up. No one knew the truth about my brain."

Mack's parents, Carol and Wally, realized shortly after her birth that something was wrong.

"There wasn't a group to turn to" said Carol Mack. "Michelle didn't have cerebral palsy, I knew that. She didn't have Down's syndrome, I knew that. I had no place to turn."

Ten years ago, Dr. Jordan Grafman, chief of the Cognitive Neuroscience Section at the National Institutes of Health, finally diagnosed the problem.

An MRI scan revealed she was missing nearly half of the left side of her brain. While it was clear Mack has some problems, Grafman said he and the family were shocked by the extent of the damage.

"We were surprised to see the extent of the lesion in her brain, which basically took away the left side of her brain" said Grafman. "There's some very deep structures remaining, but the surface of her brain, the cortex is 95 percent gone and some of the deeper structures, structures that control movement, are missing. These are all structures that are important for movement, behavior, cognition."

The only answer, Grafman said, was that Mack's brain has rewired itself. The remaining half took over some of the essential functions that are normally done by the left, such as speaking and reading. That rewiring, however, came at a cost.

"Michelle has fairly normal language abilities, certainly basic language abilities, she can construct a sentence, she can understand instructions, she can find words when she's talking, but actually she has some trouble in some aspects of visual-spatial processing" said Grafman.

"It's quite possible that in her learning, in her development, when the right hemisphere either took over or developed some of the language abilities that it cost her in some of the skills that are normally mediated by the right side of the brain" added Grafman.

In the 10 years since Grafman first diagnosed Mack, she has seen some intellectual functions improve, the doctor said. Recovery has not been perfect, however. Mack still struggles with abstract concepts and becomes easily lost in unfamiliar surroundings.

The diagnosis explained why Mack had experienced a lifetime of difficulty controlling her emotions.

"He's helped us understand the reason why I tend to throw fits, temper tantrums" she said. "It was because I was missing half my brain."

Mack will always have some problems, but dad Wally Mack said that Grafman's diagnosis and treatment answered a lot of questions and gave him hope.

"Dr. Grafman explained that the right hemisphere is taking over, and it might take her a little while longer to get there with all the rewiring that has to take place" he said. "But that told us all these bad days are behind us and there are nothing but good days ahead."

Michelle Mack is now 37 and lives with her mother and father. She works from home doing data entry for her church. She is fairly independent, pays rent and can do most household chores. She realizes she'll need help for the rest of her life but wanted to tell her story to make it clear that she is not helpless.

"I wanted to do this so people like producers, photographers and security guards and police officers learn about people like me" she said, "that I'm normal but have special needs, and that there are a lot people like me, so that they could be more understanding."