 Viruses, Bacteria, and Vaccines
Breakthrough in the race to find antidote to Alzheimer's
BACTERIA-EATING SYNTHETIC VIRUS
WASHINGTON
US researchers have created an artificial bacteria-eating virus from synthetic genes. The Phi-X174 bacteriophage was developed from its genetic code. It took the scientists just 14 days to make the artificial virus-against several years for other methods-according to the National Academy of Sciences.
The breakthrough could be the first step on a long path toward helping fight certain incurable diseases or gobbling up toxic waste, according to the experts. It could also help create organisms that can live in extreme conditions such as radioactivity and intense pollution.
The work was led by Craig Venter, head of the Institute for Biological Energy Alternatives (IBEA), who has also been closely involved in work on mapping the human genome sequence.
Scientists had previously built a poliovirus from parts of other living things in stages that can take months or years. However, Venter's team began "from scratch"-using commercially available products. They also used off-the-shelf techniques that scientists have been developing for 30 years.
To achieve such rapid results, scientists adapted a technique that produces a double-stranded copy of an individual gene sequence. The technique is used to decode DNA for forensic identification of criminals as well as for medical purposes. This polymerase chain reaction technique took 14 days to create an identical DNA of the virus.
The virus is not capable of attacking human cells, scientists were quick to point out.
"The potential for this research to revolutionize our future is enormous," US Secretary of Energy Spencer Abraham said. "Researchers have made an exciting scientific advance that may speed our ability to develop biology-based solutions for some of our most pressing energy and environmental challenges. With this advance it is easier to imagine-in the not-too-distant future-a colony of specially designed microbes living within the emission-control system of a coal-fired plant, consuming its pollution and its carbon dioxide, or employing microbes to radically reduce water pollution or to reduce the toxic effects of radioactive waste."
MUTANT CLUE ON CYSTIC FIBROSIS
PARIS
Experts believe they have found a molecular chink in cystic fibrosis. An inherited disease, cystic fibrosis is a disorder in which the lungs become clogged with thick, gluey mucus inhabited by Pseudomonas aeruginosa.
Infections by P. aeruginosa are the leading cause of death from cystic fibrosis. Patients with this disease usually have a life expectancy of just 20 to 30 years. One reason for this is that antibiotics often cannot attack the bug, because it is cocooned in a sugary "biofilm" in the lungs. Protected this way, the bacterium can be up to 1,000 times more difficult to kill than pathogens that are free-living.
Researchers led by George O'Toole at Dartmouth Medical School, New Hampshire, believe they may have found a way into this armor. They examined a newly isolated mutant strain of P. aeruginosa and found it produces a sugary protein called a periplasmic glucan that specifically binds to tobramycin, a frontline antibiotic in cystic fibrosis. Like a sticky shield, the glucan latches onto the antimicrobial agent, holding it within the biofilm to prevent it from getting to its target.
The discovery should open up new ways of attacking P. aeruginosa, using a "co-therapeutic approach" in which one drug deactivates the glucan to let the antibiotic reach the bacterium unhindered, said the study published in Nature.
EBOLA VACCINE UNDERGOES TESTING
WASHINGTON
The first human trial of a vaccine designed to prevent Ebola infection began mid-November in the United States. The US National Institutes of Health said 27 volunteers aged 18 to 44 will take part in the trials. Six of them will be injected placebo while 21 will receive the experimental vaccine, which does not contain any infectious material from the Ebola virus.
Those vaccinated will receive three injections in a space of two months. Doctors will monitor their condition for a year.
The vaccine is based on experiments conducted three years ago by Vaccine Research Center Director Gary Nabel, who demonstrated the vaccine's ability to fully protect monkeys from lethal infection by the virus.
NEW TB STRAIN FOUND IN SOUTH AFRICA
CAPE TOWN
A rare new "super" strain of tuberculosis that is costly and time-consuming to treat has been identified in South Africa's Western Cape province.
Tommie Victor, a professor of medical biotechnology at the University of Stellenbosch near Cape Town, said a team of scientists and health workers identified the strain after conducting research in 72 clinics in the Western Cape over the past three years. "We identified various strains of TB that are new to South Africa, one of them the DRF150, has never been identified anywhere in the world before," he said.
Victor said the team, which published its findings in the European Journal of Tubercle and Lung Disease, found that DRF150 was resistant to almost all antibiotics used to treat tuberculosis. "Usually five drugs are used to combat TB. The DRF150 strain is resistant to four of these," he said.
Victor said the new strain had its epicenter in the town of George, about 400 kilometers east of Cape Town, where about 60 cases had been identified. About 20 other cases have been identified in other parts of the Western Cape, but isolates of the new strain have also been found in the Mpumalanga province and in Nairobi, Kenya.
South Africa has the seventh-highest number of TB cases after India, China, Indonesia, Bangladesh, Nigeria, and Pakistan, according to the WHO. Last year it reported 224,420 cases of tuberculosis.
PROMISING VACCINE AGAINST PNEUMONIA
WASHINGTON
A vaccine against pneumonia has reduced by 25 percent the cases of the disease in 40,000 children in a clinical trial in South Africa. The three-year study published in the New England Journal of Medicine also found that the experimental vaccine reduced the incidence of pneumococcal bacteria in the bloodstream by more than 65 percent in children infected with HIV and by more than 83 percent in non-HIV-infected children.
"With the reduction in the incidence of pneumonia in the developing world, we could potentially save over 500,000 lives each year," said Keith Klugman, professor of international health at Emory University in Atlanta, Georgia, and principal author.
In Cuba, researchers say they have produced the first synthetic vaccine against pneumonia and meningitis. Vicente Verez, head of the University of Havana's Antigen Research Center, said the vaccine was designed to be administered to infants in three doses-at two, four, and six months-with a booster at 18 months. Clinical studies showed that more than 99 percent of babies vaccinated developed antibodies against the pneumonia and meningitis viruses, he said.
MEDIUM-FIRM IS BEST FOR BACK PAIN
PARIS
The widespread notion that firm mattresses are best for people with lower back pain has been demolished by a medical study published in The Lancet that says the problem is best tackled by mattresses of medium firmness.
Spanish researchers recruited 313 volunteers with lower back pain and replaced their mattresses either with a firm substitute or a medium-firm one. The individuals were asked to describe their degree of pain while lying in bed and rising in the morning, as well as their level of disability, both before the study and three months after. None was aware of the type of mattress they were lying on.
People with medium-firm mattresses (rated 5.6 on the European scale of firmness) were twice as likely to report improvements in pain level and disability and half as likely to need painkillers as those on the firm ones.
PROGRESS IN RACE FOR ALZHEIMER'S TREATMENT
SYDNEY
Researchers have developed a fast-track drug testing system that could cut decades off efforts to find a cure for Alzheimer's and other age-related diseases.
Ashley Bush of Melbourne University and Harvard Medical School said the breakthrough allows scientists to systematically screen thousands of drugs in a test tube situation to identify compounds effective in treating these illnesses.
The new process eliminates a significant step in the testing process of new drugs and should cut decades off the hunt for a treatment for Alzheimer's and chemically-similar diseases, he said. "This is a big step forward because now that our system allows us to predict drugs that work in animals, the next big step is to see whether these same drugs work in human beings."
Bush, one of the world's leading dementia experts, said the new testing system might also help develop treatments for diseases with chemical similarities to Alzheimer's. "Our team is now investigating whether the system can be applied to Parkinson's Disease and cataracts," he said.
The new process permits thousands of drugs to be tested systematically against other chemicals for positive reactions with the protein Amyloid, believed to cause Alzheimer's.
"Rather than looking for a needle in a haystack, we now have a system of identifying drugs by putting them in the test tube in large numbers and then picking out the candidates" for use in trials, he said.
The process has been developed over the past decade by a team of 35 scientists from Melbourne University, the Mental Health Research Institute, Harvard Medical School, and the Australian firm Prana Biotechnology.
The system has already led to clinical trials of the drug Clioquinol, an antibiotic that researchers have found shows early results of stopping the progression of Alzheimer's.
"Clioquinol itself is still in clinical trials and if all goes well that drug might be available as early as within three to five years," Bush said. The next generation of drugs developed by the new technology could be available within five to 10 years, he added.
Meanwhile, Berlex Pharmaceuticals, the US subsidiary of German pharmaceutical group Schering, said it had discovered a molecule that could enable the diagnosis of Alzheimer's disease at an early stage. The molecule, CCR1, is generally present on the surface of white blood cells and is "also detected in the brains of patients afflicted with Alzheimer's disease, even at a very early stage," said Meredith Halks-Miller, director of the firm's pharmaceutical branch. The number of such molecules appears to increase as the disease develops.
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