Developments to Watch
A Virus in Armor Could Be a Boon to Nanomedicine
Viruses are pesky germs that have evolved a battery of strategies to outwit the body's defenses. Now scientists have discovered that one virus, HK97, does battle in a coat of armor similar to the chain-mail suits worn by medieval knights. The research, which was reported in the Sept. 22 issue of Science, has major implications for nanomedicine, a rapidly growing research area that uses tiny machines to repair the body on the molecular level.
An international team of scientists used special micro-imaging techniques to analyze HK97's outer shell. "The proteins in the coat loop through each other--much like the Olympic rings," says lead author William R. Wikoff of the Scripps Research Institute in La Jolla, Calif. Wikoff calls these interlocking protein rings "catenanes" and believes they could be the secret to the virus' toughness. Just as chain mail is designed to deflect arrows, these catenanes are built to repel insults from the body's immune system and the environment.
Wikoff believes that researchers will one day use HK97 to carry drugs or chemicals to specific locations in the body. Empty it of its DNA, and the virus is a "molecular balloon--big and thin-walled--that can be filled up with anything," he says.Edited by Ellen LickingReturn to top
Return to top
This Gene Puzzle May Be Simpler Than We Thought
Geneticists have made progress identifying the genes responsible for such illnesses as muscular dystrophy and cystic fibrosis. Both are brought on by a defect in a single gene. But finding the many genes responsible for brain diseases such as anxiety and schizophrenia has proved to be far more challenging.
Researchers at the Salk Institute for Biological Studies in La Jolla, Calif., are now closer to solving that puzzle. Using "gene chips" from Affymetrix Inc. to analyze 10,000 genes at once, they have found a group of genes that seem responsible for sharp differences in behavior between two strains of laboratory mice.
One strain of mice is prone to anxiety and likes to drink alcohol. The other is not anxious and won't take a drink. The surprise is that these differences are explained by only a handful of genes--about 70 of the 10,000 that the researchers looked at. "The implication is that it doesn't take thousands of genes to give rise to a disorder like anxiety," says the study's senior author, Dr. Carrolee Barlow, an endocrinologist at the Salk Institute.
That's good news: It means that the puzzle of gene interactions in brain disorders might not be as difficult to solve as researchers had feared.By Paul Raeburn; Edited by Ellen LickingReturn to top
Getting a Jump on Diabetes
Diabetes can have dire side effects, among them blindness, kidney failure, and heart disease. Now, an experimental blood test seems able to pinpoint which patients are most likely to develop these complications by measuring the size of a certain protein.
The high blood sugar that plagues diabetics releases free radicals in the blood that can damage the eyes, kidneys and arteries--but only in some patients. A research team at the Technion-Israel Institute of Technology in Haifa say that patients without such complications are protected by very small molecules of the blood protein haptoglobin, which are particularly effective at cleaning up free radicals. Diabetics with complications tend to have larger haptoglobin molecules.
In a test of 53 diabetics reported in the New England Journal of Medicine, researchers found that 83% of those patients with the larger molecules suffered heart disease, 60% eye damage, and 34% kidney damage. None of those with the smaller molecules had heart or kidney damage, and only one had eye damage. The test, researchers said, would provide guidance to doctors in choosing the proper treatment. "If we can pinpoint at an early stage those predisposed to [blindness], we can introduce intensive treatments early to reduce or eliminate the onset on blindness," says Dr. Robert S. Sherwin of the American Diabetes Assn.By Catherine Arnst; Edited by Ellen LickingReturn to top