Tuesday, November 29, 2005

Controversial Chinese Neurosurgeon Gives Hope to Paralysis Patients

BEIJING - When Leo Hallan woke up in a hospital and found out he was paralysed from his chest down from a motorcycle accident in 1976, he thought his life was over.

The 20-year-old had also lost sensation in both his arms and hands.

Doctors told him he would have to live with the disability for the rest of his life.

Sitting in a wheelchair in Dr Huang Hongyun's clinic in the Beijing Xishan Hospital recently, the 49-year-old American told of a miraculous moment when he was able to regain some of his sense for the first time in 29 years.

Shortly after Huang injected Olfactory Ensheathing Cells (OEC) into his spinal cord, he started noticing changes - within a week, he started perspiring below his chest and could feel the chill of the wind for the first time when he went outdoors in his wheelchair.

"When I was outside, I felt cold in my arm, the hair of my arm was moving, I had to look down to believe it," said a cheerful-looking Hallan. "Words cannot express my emotions.

"It was total amazement, just unbelievable," he said. "Twenty-nine years ago ... many doctors said I'd never walk again. At least now I can say there is quite a bit of hope."

Hallan is just one of some 800 patients who have been seen by Huang, whose controversial approach to treating Amyotrophic Lateral Sclerosis (ALS) and spinal cord injuries by injecting cells from aborted foetuses has been sceptically received by many western medical experts.

Almost all of his patients are foreign, from countries including Spain, Germany, France, Japan, New Zealand, Singapore and Pakistan, though most are from the United States.

Huang's centre said most of its spinal cord injury patients have regained some sensory and motor function, as well as the control of urine and bowel movement, while most ALS patients had seen indefinite stabilisation in their neurological function.

"Most of our patients have obtained significant functional improvement to various degrees and about 70 percent of the patients have obtained some improvement in the quality of their lives," his centre's website said.

But Huang's Western sceptics say the effectiveness of his approach has not gone through rigorous tests and some even accuse him of exploiting desperate patients as laboratory mice.

"I haven't come across anyone in the field who considers his procedures safe and effective," said Professor Geoffrey Raisman at the Institute of Neurology, University College of London, who is pioneering research on OECs.

"He is the only one who claims it works, other people who have examined some of his patients said they saw no improvement."

Moreover, western doctors say Huang doesn't systematically keep track of his patients so there is no statistical data on how many experience lasting benefits, and he fails to perform controlled studies considered necessary in western circles.

But that doesn't bother his hopeful patients.

Hallan, who had been told by western doctors his condition would never improve, swore by Huang's treatment.

He said didn't mind "at all" being a laboratory mouse and that many other patients like him were desperate to try out new treatments, even if they had not undergone enough tests.

"The fact that this has moved on from rat (to human) is one of the most exciting prospects," he said. "There is risk in anything. You have more chance of dying just walking on the street."

From his spartan office decorated with calligraphy extolling his work ("Miracle hands bring back life"), an exasperated Huang argued impassionately and defensively against the criticisms.

He said the placebo-controlled trials that some critics say he should conduct were unethical and not permitted under Chinese law because it would mean effectively deceiving patients into believing they had been treated when they hadn't.

"For someone like Mr Hallan who had been ill for 29 years, it would be cruelty to let him have that done to him," Huang said.

"What is the priority here? Science or the patients?"

He also lashed out at the hyprocrisy of those who criticise him for his use of nasal linings of aborted foetuses, arguing that western countries such as the US are already using embryonic cell implants to treat Parkinsons disease.

"So only you are allowed to do this and we are not allowed to do this?" he said.

Another American patient, Doug McGuiness, who had two tiny holes drilled into his skull and then an injection of two million OEC cells, said even if his improvements were only temporary, the US$20,000 treatment fee would still be worth it.

Eight years after being diagnosed with ALS, the 59-year-old engineer was overjoyed when he could button his own shirt and raise his legs without help just two days after the operation.

"This is a terminal disease, it's worth it even if it is three months, six months, a year," he said, remarking that most ALS patients only have three years to live.

Even though it is still unknown exactly how the foetal tissue might work on damaged brains and spinal cords, Huang argued that this shouldn't stop the technique being used when it has been proven to work.

"Why do we need to eat and sleep, do we know? Is that a reason to stop eating?" he challenged.

Huang put the wide scepticism down to discrimination.

"They have a prejudiced attitude. They think it is implausible that a developing country like China can develop something that America and European countries haven't done yet.

"They can't accept that China is ahead of them."

With more trials of combinations of different techniques, Huang said it might be a possibility for his patients to walk in the future, but carefully emphasised that this was only one step in a very long process.

"Maybe eventually, but we don't have the solution here right now," Huang said.

But his critics remain unconvinced.

"I would be delighted if he would present evidence his OECs are working in his patients and ... it would have enormous impact on the field," Raisman said.

"But unless he can provide data to convince other experts in the field, it is pointless." - AFP/de
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Monday, November 14, 2005

Geron Wants to Test Stem Sell Spinal Cord Treatment in Humans

Scientists have made stunning progress helping paralyzed rats and mice walk again by injecting them with stem cells. Now researchers at Geron of Menlo Park want to take the next step -- in people.

They hope to get federal permission to inject those cells into damaged spinal cords. The procedure -- which Geron intends to do next year -- would be the first human tests of a treatment derived from human embryonic stem cells, the highly versatile body cells that can be coaxed into becoming almost any tissue in the body.

If the U.S. Food and Drug Administration gives its OK and the injections help, it could bring hope to many of the more than 250,000 people in this country with spinal disabilities.

"We don't have our hopes sky-high,'' said Don Reed of Fremont, whose son Roman Reed was left a quadriplegic after breaking his neck in a college football game 11 years ago. He also hopes the FDA and Geron don't rush into human tests until all safety concerns are resolved.

But if Geron's procedure helps patients, "it would be fantastic,'' Reed added. "Nobody should go through the hell that paralyzed people have to.''

Nonetheless, the plan has aroused concerns among some stem-cell researchers who claim Geron is moving too fast. They have urged the company to do more tests in non-human animals before trying it in people, because they fear cells could cause tumors or other health problems in those receiving the injections.

"Frankly, I cannot conceive of a human trial with the use of human embryonic stem cells following immediately from experiments in rodents only,'' said Jerry Silver, a neuroscience professor and stem-cell researcher at Case Western Reserve University in Cleveland. "Many treatments that work in rodents to alleviate disease fail miserably in humans.''

Stem cells are the body's basic building blocks and they essentially fall into two major categories: embryonic stem cells, which can grow into any tissue, and adult stem cells, which are more specialized and less flexible.

Treatments derived from adult stem cells already are being used to help people with everything from cancer to various blood disorders. But adult stem cells can be difficult to locate for study, are limited in the body and sometimes develop abnormalities that can hinder their medical usefulness.

Working with embryonic stem cells, first isolated in 1998, can pose problems, too. For one thing, they are highly controversial because the only way to obtain them for research is to destroy an embryo. As a result, President Bush in 2001 severely limited federal money for studies involving human embryonic stem cells.

More flexible

But because those cells are so versatile and easy to grow in large numbers in laboratories, they can be turned into treatments more easily and at less cost than is the case with adult stem cells, many scientists maintain. And given what has been learned from tests of human embryonic stem cells in rodents with spinal cord injuries, Geron executives believe it is time to see if the cells can be used on people, too.

Spinal cord injuries frequently damage one part of nerve cells called axons, the long wire-like extensions of the nerve cells. That damage disrupts the axon's ability to transmit information, resulting in paralysis.

For its test, Geron proposes to turn human embryonic stem cells into the precursors for specialized nerve cells, called oligodendrocyte progenitor cells. Surgeons then would inject the cells into the spinal injury with the help of a special stabilizing frame the company has developed.

If everything goes as planned, the progenitor cells would help form new axons and also turn into oligodendrocytes, which help form an insulating sheath for the axons, called myelin.

The test probably would involve a few dozen patients, all of whom would have irreversible spinal injuries. Initially, the idea would be to merely determine if the injections were safe. But Geron executives hope additional tests would demonstrate the procedure's effectiveness in repairing damaged axons and restoring motor function in less severely injured people.

Geron has been collaborating with researchers at the University of California-Irvine, who reported in October last year that paralyzed rats could walk nine weeks after being injected with oligodendrocyte progenitor cells derived from human embryonic stem cells.

The FDA did not return phone calls seeking comment on Geron's planned test.

Dr. Irving Weissman, director of the Stanford Institute for Stem Cell Biology and Regenerative Medicine, said he saw no reason the agency should turn down the company or demand that additional non-human tests be done first.

"They better not,'' Weissman said, "because then they're putting themselves right in the way of treating humans for disease.'' Weissman is also a board member and co-founder of StemCells, a Palo Alto company that won federal approval in October to transplant adult stem cells into the brains of children to correct a fatal disorder.

Other targets

If the Geron test gets the OK and proves effective, the company hopes to seek approval eventually for similar tests of human embryonic stem-cell therapies for congestive heart failure, Parkinson's disease, diabetes and osteoporosis, among other things.

But other scientists are skittish, including Evan Snyder, director of the stem cell and regeneration program at the Burnham Institute in La Jolla. He praised Geron for making great progress with its research. Nonetheless, he said the company should do more non-human tests, and make sure their tests precisely mimic the kinds of spinal cord injuries humans get.

"I'm not convinced they have done that yet,'' Snyder said.

Cancerous side effects are another worry. Because human embryonic stem cells can become any tissue, Arnold Kriegstein, director of the Institute for Stem Cell and Tissue Biology at UC-San Francisco, fears the injections might trigger tumors. As a result, he said, the FDA and Geron need to be especially cautious.

"The bar would have to be a little higher'' for human experiments, Kriegstein said. "There is a great potential for harm.''

Still others are nervous about Geron using a federally approved line of stem cells, many of which have been nourished in so-called feeder layers made from mouse or calf tissue. Studies have found such cells can be contaminated with a molecule that could prompt an immune system attack if injected into humans.

But Geron's chief executive, Dr. Tom Okarma, said none of those concerns warrant banning human tests.

For one thing, he said, Geron has developed feeder layers that are free of contamination. And to prove it, Geron published data last year that found no immune response in mice injected with its human embryonic stem cells.

Okarma said no cancer has turned up in any animals that have received the company's cells, either.

And although Geron is still compiling data in preparation for filing a formal request to the FDA to do the test, he's confident from the work already done at UC-Irvine and at his company that the procedure will be safe.

"We're turning over every stone,'' to avoid harming anyone in the experiment, Okarma said. "The last thing in the world a public company wants to do is fall on its nose in its first clinical trial.''

By: Steve Johnson - Mercury News
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Tuesday, November 01, 2005

Cyberknife Surgery Shows Promise in Spinal Metastases

PARIS, FRANCE - Cyberknife image-guided radiosurgery is effective and generally safe for managing spinal metastases, according to data announced on October 31st at the 13th Annual Meeting of the European Cancer Conference (ECCO).

Iris Gibbs, MD, Assistant Professor of Radiation Oncology, Stanford University Medical Center, Stanford, California, United States, described results obtained in 103 spinal metastases treated using Cyberknife image-guided radiosurgery.

The Cyberknife is a unique image-guided frameless stereotactic radiosurgery delivery system that consists of a lightweight linear accelerator mounted on a robotic arm. Real-time imaging allows for patient movement tracking with 1-mm spatial accuracy. The Cyberknife System is approved by the FDA to provide radiosurgery for lesions anywhere in the body when radiation treatment is indicated.

Dr. Gibbs and colleagues enrolled 74 patients; 84% were symptomatic, 92% received previous treatment, including 74% who received prior radiotherapy.

Using the Cyberknife inverse treatment planning algorithm, the researchers generated treatment plans of 16-25 Gy in 1-3 fractions. The limited volume of the spinal cord receiving greater than 8 Gy in a single fraction to less than 0.3 cm3. When this could not be achieved, the dose was fractionated in two to three fractions.

Patients were followed clinically and radiographically for at least 3 months or until they died. Pain was assessed using a visual analog scale.

After a mean follow-up of 9 month, 36 patients were alive and 38 were dead. No deaths were treatment-related.

Fifty (84%) of 62 symptomatic patients experienced improvement or resolution of symptoms after treatment.

There were three cases of treatment-related spinal cord injury.

Dr. Gibbs cautioned that the ease of radiosurgical treatment and its effectiveness in alleviating pain must be balanced against the possibility of spinal cord injury, especially for lesions of the thoracic spine.

By: Jill Stein
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