Prostate gene; Cryo vs. angioplasty; New kidney drug

[David]

fnaWife2AFVV

Registered to :Sep 26, 2001
Messages :198
From :
Posted 27-01-2002 at 02:55
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Couple of health tidbits from the last couple weeks:

http://www.cnn.com/2002/HEALTH/01/21...sty/index.html
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Cold as ice: Opening arteries with cryoplasty Experimental technique freezes away blockages
By Eleni Berger, CNN

(CNN) -- What if there were a way to improve on one of the most common treatments for heart disease? -- a method both easier on the body and requiring fewer repeat procedures?
Researchers say they may have found just that: a new way to clear blocked arteries that's less traumatic to the blood vessels and appears to have a lower incidence of restenosis, the reclogging of an artery that can necessitate repeat surgery.
The technique is called cryoplasty -- in effect, it's angioplasty on ice.
"Our preliminary research with cryoplasty is very promising," says Dr. James Joye, the interventional cardiologist who developed the procedure.

He and his colleagues are presenting the results of that research at the 14th annual International Symposium on Endovascular Therapy, going on this week in Miami Beach, Florida.

Laughing gas is the key
Angioplasty and cryoplasty are performed in essentially the same way: A catheter is threaded into the clogged artery, where a balloon is inflated to compress the blockage and reopen the vessel.
But there's one essential difference. In traditional angioplasty, the balloon is inflated with saline solution; in cryoplasty, the balloon is inflated with nitrous oxide -- commonly known as laughing gas.
The nitrous oxide cools to a temperature of -10 degrees Celsius, freezing the plaque and inducing a process called apoptosis, a type of cell death.
"It's almost like the cells have a switch that's like a self-destruct button," Joye says. In apoptosis, "the body compartmentalizes the cell -- sort of pinches off little pieces at a time -- and removes it."
That process is gentler on the artery wall than angioplasty, preventing much of the inflammation and scarring that contribute to restenosis, says Joye, director of peripheral vascular interventions at El Camino Hospital in Mountain View, California. He's also co-founder of CryoVascular Systems, the company that markets the device used in the procedure.

Promising early results
Cryoplasty also might eliminate the need for stents, the mesh tubes sometimes used to keep an artery propped open, Joye says. While the stents can reduce restenosis, having a foreign body in the artery can also spur more aggressive restenosis, he says.
Of the 15 patients treated in initial trials in Europe and South America, 12 have shown no signs of restenosis nine months after treatment, when renarrowing typically occurs. None has needed a stent to maintain a clear artery.

The patients were all treated in leg arteries, where restenosis rates with standard angioplasty typically approach 50 percent to 60 percent. In coronary arteries, the restenosis rate is about 20 percent to 30 percent.

"If in fact the cryoplasty continues to work as it has, what we're looking at is a very dramatic change in the outcomes of these procedures," says Joye.
With the approval of the Food and Drug Administration (FDA), Joye and his colleagues have begun a first-phase clinical trial to test cryoplasty in the coronary arteries of about 100 patients, 70 of them in the United States. Another FDA-approved trial of the technique on leg arteries is also beginning.
Joye says the cryoplasty technique is safe, with the same risks as standard angioplasty.
But he cautions that his work is in the early stages.

"It's 15 patients," he says. "It's a start. We're obviously very encouraged."

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2nd prostrate gene identified
http://www.cnn.com/2002/HEALTH/01/20....ap/index.html

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FDA OKs Drug to Fight Liver Disease
By LAURAN NEERGAARD
AP Medical Writer
WASHINGTON

Children born with a very rare but lethal liver disease _ it often kills by their first birthday _ have won the first drug that promises to help them live years longer.

The drug Orfadin amazingly is a failed weed killer that Swedish scientists discovered could fight a disease called hereditary tyrosinemia.

"This is a real breakthrough drug," said Dr. Marlene Haffner of the Food and Drug Administration, which just approved Orfadin's sale. She said scientists once referred to the drug as "Lazarene, because these kids were so sick and then they were well."

"This was an absolutely fatal disease until now," added Abbey Meyers, president of the National Organization for Rare Disorders, which is running a program for the drug's maker to ensure children who can't afford the super-expensive new therapy will get free or reduced-cost medicine.

Hereditary tyrosinemia type 1, or HT-1, is a genetic metabolic disorder that causes progressive liver failure and liver cancer in young children. It's very rare _ fewer than 100 American children, and a few hundred more worldwide, are estimated to be living with the disease.

It is not among the metabolic diseases that all newborns are tested for at birth, so often infants die undiagnosed, Meyers said.

For babies who are diagnosed, the only treatment is a special low-protein diet. The reason: When the body breaks down the amino acid tyrosine, HT-1's genetic defect causes it to produce toxins that in turn cause liver cancer. Babies can't avoid all tyrosine or they'd never grow, so the diet helps but doesn't stop the disease.

Those who survive infancy rarely live into the 20s without a liver transplant.

Orfadin may significantly improve those dismal statistics: In an ongoing study of 180 patients who began the drug in infancy, 88 percent have survived four years and counting _ far better than the normal 29 percent survival rate with diet alone.

It works by blocking formation of the liver-destroying toxins, Haffner said.

Orfadin didn't work for everyone and isn't a cure. Even in patients that the drug helped, no one yet knows if taking Orfadin for life could keep the disease at bay or if eventually they would need a liver transplant. Studies to determine that are continuing.

The drug's cost depends on the dose, which varies with the child's size: $12,000 a year for an infant, up to $60,000 a year for an older child, estimated Bo Allen, vice president of Orfadin's manufacturer, Rare Disease Therapeutics.

That's cheaper than a liver transplant, and thus many insurance companies are expected to pay for it, he said. But for families that can't afford the therapy, his company will provide it for free or at a lower cost in a program run by NORD. To enroll, families may call 1-800-999-NORD.

"We're not going to let any child go without the medication," Allen pledged.

About 10 years ago, scientists at Sweden's Gothenberg University discovered how HT-1 destroys the liver and began searching chemical databases for compounds that might block that disastrous action. They found a failed herbicide created by Zeneca Inc., which eventually donated the chemical for medical use, Allen said.

The tiny Nashville-based company won FDA approval under a special law that allows seven years of marketing exclusivity for products that treat rare diseases.
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On the Net:
Food and Drug Administration: http://www.fda.gov

Rare Disease Therapeutics: http://www.raretx.com

National Organization for Rare Disorders: http://www.rarediseases.org

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