Individuals with persistent stuttering have anatomic irregularities in the areas of the brain that control language and speech, according to a report in the July 24 Neurology. Using magnetic resonance imaging to measure the brains of 16 patients with persistent developmental stuttering (PDS) and 16 controls, researchers from Tulane University found that the right and left temporal lobes were significantly larger in the adults with PDS. In addition, irregularities in the shape of the brain were much more prevalent among patients with PDS than among controls.

The 1999 New York City outbreak of West Nile virus infection was greater than previously thought, according to a report in the July 28 Lancet. The study concluded that a substantial outbreak of West Nile fever accompanied the 59 cases of West Nile meningoencephalitis and that for every diagnosed case of meningoencephalitis there were likely to be 140 other infections, including 30 cases of an influenza-like illness.

Researchers have pinpointed the gene on chromosome 3 responsible for myotonic dystrophy type 2 (DM2). According to University of Minnesota investigators, the defect occurs in an intron, which provides strong evidence that RNA alone can cause disease. More specifically, the findings indicate that DM2 is triggered by an expansion located in intron 1 of the zinc finger protein 9 gene. Previous research had focused on protein abnormalities as the cause of genetic disorders. “For the first time there is indisputable evidence that RNA itself can cause disease,” said study coauthor John Day, MD, PhD. The findings were reported in the August 3 Science.

Hypertensive men who don’t manage stressful situations with composure may be at an increased risk of stroke, according to a report in the August Stroke. In a prospective study of the association between adaptation and stroke incidence, investigators found that strokes among hypertensive men who became flustered during a stress-inducing test—the Color Word Test—were nearly double compared with men who remained calmer. Researchers followed 238 elderly Swedish men from 1982 and 1983 until first stroke, death, or the predetermined date of the study’s close. Based on their findings, the researchers suggested that it may be possible to identify and offer behavior counseling to individuals who have difficulty handling stressful situations, thereby reducing their stroke risk.

While working with yeast, researchers have discovered that the presence of one prion protein can spark the formation of other unrelated prions similar to the protein thought to be responsible for Mad Cow disease and Creutzfeldt-Jakob disease (CJD). The finding that one prion can help start a chain reaction in a totally different protein is important, researchers reported in the July 27 Cell, because much more is known about how prions propagate than about how they initially appear. “It’s a great concern that humans can acquire [CJD] from infected cattle, but far, far more cases arise spontaneously,” said Dr. Susan Liebman, a biology professor at the University of Illinois at Chicago. Dr. Liebman and colleagues have also devised a screening test that can pinpoint unidentified prions.

Using a new vaccine, researchers have prevented the development of Alzheimer’s disease in mice genetically engineered with the human gene for the disease, according to a study in the August 2 American Journal of Pathology. Investigators from New York University’s School of Medicine are optimistic that this new vaccine is safer than one already being tested in early human clinical trials. The new vaccine, which utilizes a nontoxic, non-fibrillar amyloid-beta homologous peptide, reduced the amount of amyloid plaque in the brains of mice by 89% and reduced the amount of soluble amyloid beta in the brain by 57%. The researchers believe that early clinical trials of the new vaccine could begin within a year.

Feverfew, an herbal remedy commonly used for migraine, may be used to develop new anti-inflammatory drugs, according to a report in the August Chemistry and Biology. Researchers at Yale University have shown that parthenolide, an anti-inflammatory component in feverfew, targets the protein I kappa B kinase and halts that protein’s role in the inflammation process. “The results pave the way for the development of novel anti-inflammatory drugs for a variety of illnesses and symptoms, such as headache, swelling, redness, and inflammation,” said Craig Crews, PhD, who led the research team.

Voxel-compression mapping of serial magnetic resonance images provides a valuable technique for in vivo monitoring of the progression of Alzheimer’s disease and may be applied diagnostically to study the effects of therapeutic intervention, according to a report in the July 21 Lancet. Researchers said that because of its ability to localize differing patterns of cell loss, voxel-compression mapping may also be applicable to the study of other degenerative dementias. The voxel-compression maps localized progressive atrophy in patients with preclinical Alzheimer’s disease and confirmed early involvement of the medial temporal lobes but also showed posterior cingulate and temporoparietal cortical losses at the presymptomatic stage. According to the researchers, the ability to diagnose early and track the progression of Alzheimer’s disease from the earliest symptomatic stages has implications for the assessment of new treatments.

Men with constipation are nearly three times as likely to develop Parkinson’s disease later in life than are men without constipation, according to new research. Although constipation is a major gastrointestinal disorder among people already diagnosed with Parkinson’s disease, results of a prospective study reported in the August 14 Neurology show that constipation can predate symptoms of Parkinson’s disease by many years. The study involved 6,790 men ages 51 to 75 who were followed for 24 years. Men in that group who were constipated were 2.7 times more likely to develop Parkinson’s disease than were men who had an average of one bowel movement per day. According to the researchers, further study is needed to determine whether constipation is part of early Parkinson’s processes or is a marker of susceptibility or environmental factors that may cause Parkinson’s disease.

The placebo effect in Parkinson’s disease is mediated through activation of the already impaired dopamine system, a finding that may impact the interpretation of clinical trials, according to a report in the August 10 Science. Researchers from the University of British Columbia used positron emission tomography to study the release of dopamine in response to placebo, given along with apomorphine, in six patients with Parkinson’s disease. The investigators noted that dopamine release in the nigrostriatal system is linked to an expectation of a reward—in this case, the anticipation of therapeutic benefit. Placebo treatment brought significant decreases in raclopride binding, indicating increases in dopamine release. These decreases matched those seen in the same patients when they were treated with apomorphine.

Antioxidant vitamin supplements may nullify a key beneficial effect of the cholesterol-lowering drugs niacin and simvastatin, according to a new study. Compared to treatment with drugs alone, the combination of antioxidant vitamin supplements and cholesterol-lowering drugs resulted in a smaller increase in high-density lipoprotein (HDL) cholesterol, according to a report in the August issue of Atherosclerosis, Thrombosis, and Vascular Biology. The adverse effect on HDL appeared specific for the HDL(2) component, which is responsible for most of the risk-reducing benefits of HDL. An accompanying editorial urged physicians to advise their patients that the use of antioxidants could be hazardous, especially in combination with lipid-lowering drugs.

Researchers have discovered what appears to be a fifth photoreceptor in the eye that is responsible for regulating melatonin production and, in turn, the body’s biological clock. Investigators from Thomas Jefferson University have identified a novel photopigment in the eye responsible for reacting to light and controlling the production of melatonin. As reported in the August 15 Journal of Neuroscience, the researchers have also discovered that wavelengths of light in the blue region of the visible spectrum are the most effective in controlling melatonin production. The investigators believe that their discovery will impact the therapeutic use of light for treating winter depression and circadian disorders.

University of California, San Francisco, researchers have determined that two drugs currently approved to treat either malaria or certain psychotic illnesses—quinacrine and chlorpromazine—are effective in treating prion-infected mouse cells. Because the drugs have long been used, are known to cross the blood-brain barrier, and caused a dramatic response in the cells, the investigators advocate immediate clinical trials to study the efficacy of the drugs in patients dying of prion diseases. Results of the study were published in the August 14 Proceedings of the National Academy of Sciences.

A drug used to treat anemia, chronic kidney failure, and drug toxicity—and illegally used by some athletes to enhance performance—could provide a new treatment for Alzheimer’s disease, according to a report in the August 9 Nature. Researchers have found that the kidney hormone erythropoietin (EPO), which regulates the production of red blood cells, also protects certain neurons in the brain from apoptosis in response to the kind of damage caused by Alzheimer’s disease. Some athletes use a synthetic version of the hormone to increase the number of oxygen-carrying red blood cells in their bodies. Investigators from the Burnham Institute in La Jolla, California, subjected rat neurons in the laboratory to nitric oxide, a natural substance that in excess amounts can trigger cell suicide, and found EPO protected the cells and prevented them from dying.

A nonembryonic source of stem cells that can produce different cell types, including the type of neural cells needed to potentially help patients recover from a spinal cord injury or Parkinson’s disease, has been identified. According to a report in the September Nature Cell Biology, researchers from the Montreal Neurological Institute at McGill University have isolated stem cells from the dermis of adult rodents that will proliferate and differentiate in culture to produce very different cell types, including neurons, glia, smooth muscle cells, and fat cells. These novel stem cells, called SKPs, were isolated from the skin of juvenile and adult rodents—an accessible nonembryonic source. Human studies have indicated that similar cells are present in adult human skin.

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