A Double Whammy for the Common Cold
Scientists have come close, but there’s still no cure for the common cold. The problem isn’t just killing the virus--though that’s an important step--it’s also subduing the chemicals the body unleashes in response to the invasion.
Knowing this, University of Virginia researchers tried another strategy. They combined the antiviral drug interferon with two drugs (chlorphentramine and ibuprofen) that counteract chemicals such as histamines and prostaglandins, which cause the sneezing, runny nose, sore throat and lethargy that lay us low. In a study comparing that regimen with one consisting of the two pills and placebo drops and another consisting of placebo pills and drops, the new cold-fighting combo stopped the virus and reduced the symptoms by as much as 73%.
The first three days of a cold are when the symptoms are most severe. But when volunteers started their treatment 24 hours after cold viruses were placed in their nose, their rising symptom scores flattened and then declined. Those in the placebo groups continued to climb to a peak before dropping, though there was more improvement in those taking chlorphentramine and ibuprofen than the placebo drops and pills group.
“Overall [the combination] reduced the total symptom burden by about 50%, but it varied according to the symptom. Sneezing was reduced by about 80%, mucous production dropped 71% and sore throat was reduced 44%, compared to the groups taking the placebo [drops and pills],” says Jack M. Gwaltney Jr., a professor of internal medicine at UVA School of Medicine in Charlottesville. He says it’s not known if the drugs have an additive effect or if one enhances the effectiveness of the other.
Journal of Infectious Diseases 2002; 186:147-154
Rethinking Normal Blood Counts in Older Women
Elderly women may have mild anemia to blame for their frailty, according to a new study that casts doubt on what is considered a normal level of hemoglobin for those older than 70.
Anemia is a problem for up to a third of older women, contributing to fatigue, chest pain, shortness of breath and dizziness. But it may be even more pervasive than experts believe. According to the findings, women with a low-normal hemoglobin level (12 grams per deciliter) had 1 1/2 times the risk of mobility problems as those with levels in the mid-normal range (13 to 14 grams per deciliter). Hemoglobin is a substance in red blood cells that transports oxygen.
One or two grams per deciliter makes a big difference in hemoglobin levels, but Paulo Chaves, assistant professor of medicine and epidemiology at Johns Hopkins University School of Medicine, says he was surprised that the corresponding difference in women’s physical function was so great.
“This is the first study to show that a hemoglobin level of 12 grams/deciliter may not be normal ... and that it is a modifiable risk factor for physical disability,” says Chaves, who is also an assistant professor at Rio de Janeiro State University.
Since red blood cells transport oxygen from the lungs to the tissues, a diminished supply to the muscles can make it difficult for the woman to keep up with the mobility tasks of daily life that require exercise tolerance. Chaves says this leads to deconditioning and disability.
Journal of the American Geriatrics Society 50: 1257-1264
New Spinal Fusion Technique Uses Genetically Engineered Protein
Surgery is usually the last resort for back pain. Now, after two decades of research, the Food and Drug Administration has approved a spinal fusion technique that uses a natural protein to stimulate bone growth between vertebrae, welding them together and replacing the degenerated disc.
Since the protein can be mass-produced in the laboratory using genetic engineering techniques, in many cases it may not be necessary to retrieve bone from the patient’s hip to fill the gap between the vertebrae. The protein--called BMP-2, for bone morphoenetic protein-2--is placed in a collagen-sponge that is inserted into a tapered framework, or a cage, placed between the vertebrae. The protein signals the person’s own cells to begin forming bone.
Because the technique, the Infuse Bone Graft, may not require bone from a distant site, the pain, blood loss, operating time and the risk of complications are reduced. And because about a million times more BMP-2 can be placed between the vertebrae than is present in the person’s own bone, a successful fusion is more likely.
A study comparing the two methods in nearly 300 patients found that, at 24 months, fusion rates using Infuse alone were about 6% higher than the traditional methods. There was greater than 50% improvement in low-back pain relief in both groups.
Drug Could Give Healthy Brains a Memory Boost
A drug that’s been used for years to help people with Alzheimer’s disease may be a memory booster for healthy people. Though larger studies are needed before the drug, donepezil, might be prescribed to help students taking finals or to improve a chess player’s chances of winning a match, researchers have found in a study of general aviation pilots that their ability to retain complex training instructions was significantly improved by a daily dose of the drug.
Pilots are good guinea pigs for memory drugs because they use a range of skills that tend to decline with age, and their ability to perform can be objectively measured. They may also be among the first takers, should the drug ever be used in healthy people. Now pilots for commercial airlines must retire at age 60.
In the Stanford University study, 18 pilots, whose average age was 52, were trained on a flight simulator to do difficult and unusual tasks that required remembering and processing various types of information and commands. After the initial training, half of the pilots began taking donepezil. A month later, the pilots were put to the test again.
Overall the pilots who had taken the drug did just as well during the second flights as during the training sessions, but those taking the placebo did worse, especially in the emergency situations and approaches to landings. These situations involve processing visual information, such as data gleaned from scanning the instrument panel, and making judgments based on the readings. Both involve the kind of working memory that drugs like donepezil improve.
Neurology 59:123-125
