Cure for Apnea, Back to China
Drugs versus malaria, AIDS use old Chinese remedies
SURGERY FOR APNEA
SINGAPORE
Singapore doctors claim they have developed a world-first surgery technique to cure severe sleep disorders without changing the facial structure of patients.
Surgeons from the Singapore General Hospital (SGH) and the National Dental Center said the new technique to treat obstructive sleep apnea (OSA) should benefit Asian patients who are more likely to have their profiles altered under the old method.
OSA is caused mainly by a narrowing of the upper air passageway to the nose due to the collapse of bulky soft palate tissue and the falling back of the tongue when a person sleeps.
Loud snoring, breathing pauses, choking in sleep, and frequent awakening are among its symptoms. Medical complications include high blood pressure, heart attack, stroke, depression, and dementia.
An estimated 15 percent of the adult population in Singapore and in Asia are deemed affected by this condition, the doctors said. Severe cases are treated through surgery.
Under the old surgery method, which has been employed in the US over the past 16 years, the lower and upper jaws are broken and brought forward by 10 millimeters to enlarge the air passageway. However, this has resulted in altered facial profiles, especially among Asians who emerged with more protruded jaws after the surgery, said surgeon Goh Yau Hong, a consultant with the Department of Otolaryngology at SGH.
To correct the imbalance, the Singapore surgeons also moved the jaws by 10 millimeters but developed a new technique to prevent the protrusion. It involves extracting four teeth from the upper and lower jaws. The front segment of the upper and lower jaws is then pushed backward to minimize the front protrusion.
"In bringing back the front portion of the jaw, we will have to extract some teeth generally, and we will close the gap by removing the bone in between and at the same time we are also able to advance the upper and lower jaws by the stipulated 10 millimeters and yet achieve a very flattened profile," Goh said.
"This has never been done anywhere else in the world for the treatment of obstructive sleep apnea. This is certainly a breakthrough," he said of the eight-hour operation that could cost US$7,800.
HOPE FOR MAD-COW DISEASE
PARIS
Experiments using mice have boosted hopes that antibodies can be a useful weapon in the fight against the human form of mad-cow disease.
Called variant Creutzfeldt-Jakob disease (vCJD), it is one of a family of incurable, fatal disorders in which a prion protein folds over and runs amok in the brain, destroying cells.
Mice that were infected with scrapie, a vCJD relative that affects sheep, were protected by an injection of antibodies that identify and attack scrapie prions. They remained healthy for more than 300 days, while mice that had not been treated fell sick and died. The downside, however, was that the antibodies did not work on animals already showing clinical signs of scrapie.
The findings are "encouraging and provide an important impetus for pursuing prion immunotherapeutics," the authors led by Simon Hawke of Imperial College London say.
As of February, 130 people in Britain had been diagnosed with vCJD, 122 of whom had died, according to the web site of Britain's National CJD Surveillance Unit. France has recorded six cases, five of whom have died. Ireland, Italy, and Canada have had one death. One case has been diagnosed in the US involving a Briton who had lived in the United Kingdom.
Mounting evidence has linked vCJD to eating beef infected with an animal equivalent of the disease called bovine spongiform encephalopathy (BSE). Among animals, prion diseases are known to affect sheep, mink, elk, and cows. Among humans, the prion diseases are vCJD and standard Creutzfeld-Jacob disease; Gerstmann-Straussler-Scheinker syndrome; Kuru, uncovered among cannibals in Papua New Guinea in the 1950s; and Alpers syndrome.
DNA-BASED RABIES VACCINE
BANGALORE, India
Indian scientists are set to start human trials of a DNA-based rabies vaccine after successful experiments on animals.
"Experiments on animals have been very successful and human trials are likely soon, maybe within a few months," said S.N. Madhusudanan, chief of the department of virology at the National Institute of Mental Health and Sciences (NIMHANS).
The vaccine to target rabies, a major scourge in India, was developed at the Indian Institute of Science.
"In the DNA vaccine a particular protein-inducing protection against the virus is attached to the animal or human DNA and gets integrated to the system. It starts producing antibodies for the rest of the lifetime," he said.
Madhusudanan said that in earlier vaccines, the rabies virus was inactivated before being administered, and chances of harmful proteins going into the system were higher. "Now the DNA that coded the protein or the naked DNA can be more effective," he said.
It will take at least a decade for the vaccine to be commercially available, said V. Ravi, a microbiology professor at NIMHANS. "It has to be studied whether the injected DNA induces mutation in animals," he said.
More than 30,000 people die of rabies in India every year, 60 percent of them under 15 years old.
MORE ASPIRIN USE
WASHINGTON
A daily dose of aspirin helps prevent the development of polyps and benign tumors that can lead to colorectal cancer, as well as reduce their recurrence in high-risk patients.
A seven-year study of 1,100 patients concluded that taking aspirin every day reduces polyp formation by 19 percent, researchers at the Dartmouth Medical School in Lebanon, New Hampshire reported. A weaker dose of 81 milligrams is more beneficial than the normal adult dose of 325 milligrams, they said.
Another three-year study on 517 patients who had already undergone surgery for colorectal cancer showed that a daily dose of 325 milligrams reduced recurrence of polyps by 35 percent.
But lead author Dr. John Baron said aspirin "is not a magic bullet." "Although the incidence was reduced, all the polyps didn't go away in our study. Regular screenings, perhaps including colonoscopies, are still important," he pointed out.
Dr. Richard Schilsky, professor at the University of Chicago and an author of the second study, said aspirin "had a significant protective effect." He said "it clearly reduced the formation of polyps in this study of high-risk individuals, which is good news because it provides a new way to lower the risk of recurrence in patients who have had colon cancer."
The American Cancer Society says 147,500 people will be diagnosed in the US with colorectal cancer this year, and some 57,100 will die from it.
In an article published in the New England Journal of Medicine alongside the studies, Dr. Thomas Imperiale of Indiana University urged further research, saying "aspirin cannot yet be recommended for this indication and is not a substitute for screening and surveillance." The trials nonetheless "provide proof of the principle that aspirin moderately reduces the risk of recurrent colorectal neoplasia," he added.
MALARIA BREAKTHROUGH
GENEVA
Top international organizations fighting tropical diseases have signed an agreement with an Asian drug company to develop a "breakthrough" cure for malaria based on a Chinese traditional remedy.
The World Health Organization said it hoped the pyronadine-artesunate compound would be "an affordable, well-tolerated, efficacious medicine" capable of reversing the growing ineffectiveness of existing drugs against malaria. In recent years the parasite that carries the most deadly form of the disease, Plasmodium falciparum, has become increasingly resistant to the current range of antimalarial drugs.
"It is hoped the medicine will cure acute malaria in all patients in all countries affected by Plasmodium falciparum, and that, although the final price is not known, the combination will be affordable to malaria-endemic countries," WHO said.
It described the combination drug as "a breakthrough in malaria treatment." The drug, developed with South Korean-based Shin Poong pharmaceuticals, combines artesunate (derived from the sweet wormwood plant) with pyronaradine, a newer antimalarial first developed in China. Artesunate is a compound whose antimalarial effects were first discovered centuries ago in China.
WHO expects phase one clinical studies of the compound to begin in the second quarter this year, with approval of the new combination in 2006 if trials show it is safe and effective. The partners involved are the WHO, World Bank, UN Development Program, and Medicines for Malaria Venture.
CHINESE AIDS DRUG
BEIJING
A new anti-AIDS drug based on traditional Chinese healing has been approved for use in Chinese hospitals. Known as immunicin tonic, the low-cost and easy to administer drug was developed by Cao Heyang, a researcher at the Chinese Academy of Sciences in northern Xi'an province, and has been approved for use by the State Drug Administration of China.
"Different from other AIDS drugs, immunicin tonic is designed to prevent HIV from entering human body cells while increasing the quantity and quality of white blood cells and stimulating the immune system," Cao said. "Then it restrains viral activity by bringing the immune system back to normal."
Cao began with animal tests after having spent 11 years developing drugs, and then moved to human clinical trials, obtaining an 80-percent success rate with 31 AIDS patients in China's Henan province. Early clinical use in 350 patients achieved similar rates of success.
ARTHRITIS VACCINE
BRISBANE
Australian scientists have announced a breakthrough in efforts to develop a vaccine for rheumatoid arthritis. Researchers at the University of Queensland said they identified how to reverse a process in which a body's autoimmune system attacks its own tissues, causing arthritis.
"This is really the first time we have been able to specifically target the appropriate molecule in order to get the immune system to turn off after it has already started," scientist Ranjeny Thomas said.
Thomas, deputy director of the university's Center for Immunology and Cancer Research at Brisbane's Princess Alexandra Hospital, said testing had so far been confined to laboratory mice and human trials were about two years away.
If successful, the trials could pave the way for the development of a vaccine to prevent rheumatoid arthritis, although Thomas stressed doctors would be unable to reverse existing joint damage.
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