Keeping you up-to-date on recent headlines in neurology.
STAT3 gene focus of new study ... In a study published online in advance of print in Stem Cells, Tufts University School of Medicine (Boston) researchers report that the STAT3 gene regulates cancer stem cells in brain cancer. Cancer stem cells have many characteristics of stem cells and are thought to be the cells that drive tumor formation. The researchers report that STAT3 could become a target for cancer therapy, specifically in Glioblastoma multiforme (GBM), a type of malignant and aggressive brain tumor. Patients with GBM typically survive 12 to 14 months with treatment. Treatment options include radiation, chemotherapy, and surgery. "When STAT3 is inhibited, cancer stem cells in glioblastomas lose their stem-cell characteristics permanently, suggesting that STAT3 regulates growth and self-renewal of stem cells within glioblastomas. Strikingly, a single, acute treatment with STAT3 inhibitors was effective, implying that a STAT3 inhibitor could stop tumor formation," said senior author Brent Cochran, PhD, a professor at Tufts University School of Medicine and a member of the cellular & molecular physiology program faculty at the Sackler School of Biomedical Sciences at Tufts. "We are encouraged by the potential of STAT3 in our study," said Cochran. "Research has already demonstrated that STAT3 and cancer go hand in hand, but, until this study, we did not know that STAT3 regulates cancer stem cells, which are extremely resistant to conventional therapy. Given these findings, I hope that our future research investigating the mechanisms involved in inhibiting STAT3 will contribute to more effective and less invasive cancer therapies."
Neural pathway missing in tone-deaf people ... Nerve fibers that link perception and motor regions of the brain are disconnected in tone-deaf people, according to new research in the August 19 issue of The Journal of Neuroscience. Experts estimate that at least 10% of the population may be tone deaf unable to sing in tune. The new finding identifies a particular brain circuit that appears to be absent in these individuals. "The anomaly suggests that tone-deafness may be a previously undetected neurological syndrome similar to other speech and language disorders, in which connections between perceptual and motor regions are impaired," said Psyche Loui, PhD, of Beth Israel Deaconess Medical Center and Harvard Medical School (both Boston), one of the study's authors. The authors used an MRI-based technique called diffusion tensor imaging to examine connections between the right temporal and frontal lobes. This region, a neural "highway" called the arcuate fasciculus, is known to be involved in linking music and language perception with vocal production. Brain images of 20 people were taken, half of whom had been identified as tone-deaf through listening tests. The arcuate fasciculus was smaller in volume and had a lower fiber count in the tone-deaf individuals. More notably, the superior branch of the arcuate fasciculus in the right hemisphere could not be detected in the tone-deaf individuals. The researchers speculated that this could mean the branch is missing entirely, or is so abnormally deformed that it appears invisible to even the most advanced neuroimaging methods.
Seeking New Smoking Cessation Target ... The National Institutes of Health (NIH) has awarded a scientist at the Barrow Neurological Institute at St. Joseph's Hospital and Medical Center (Phoenix) a $275,000 grant to study a rare brain receptor that may be a new smoking cessation target. Throughout the next two years, researcher Paul Whiteaker, PhD, and other scientists in the Barrow Neurochemistry Laboratory will use the NIH Exploratory/Developmental grant to create an artificial system to produce the rare a6 nicotinic receptors normally found in the brain. They will then be able to study the way potential therapeutic drugs interact with this key receptor that has been implicated in diseases ranging from addictions to Parkinson's disease. Previous studies have been hindered because of the a6 receptors' scarcity and the complexity in studying them in isolation from other nicotinic receptor types. "By creating this artificial cell line we will have the opportunity to produce pure populations of these receptors on demand, examine drug interactions quickly and in great detail, and study specifically how a6 receptors interact with potential new smoking cessation therapies," says Dr. Whiteaker. "If we can precisely target the neurons that express a6 receptors without involving others, we can develop treatments that may be more effective and have fewer side effects than current smoking treatments."
Neurological complications of heart surgery ... Possible neurological complications of heart surgery, ranging from headaches to strokes, are detailed in a new report in the online journal MedLink Neurology. The review article, which compiled results of previously published studies, was written by Betsy Love, MD, Sara Hocker, MD, and senior author Jose Biller, MD, of Loyola University Chicago's Stritch School of Medicine. In the review, researchers list possible nervous system complications of bypass surgeries, aortic surgery, cardiac catheterizations, valve replacements, heart transplants and surgeries for congenital heart disease and heart tumors. For example, possible complications from bypass surgery include vision problems, paralysis, hoarseness, movement disorders and disturbances in learning, memory, attention, concentration and mental agility. Depending on the patient's age, the operating techniques used and other factors, the risk of stroke ranges from just under 1% to as high as 5%, according to studies cited in the article. "Neurologic complications of cardiac procedures can involve literally any part of the central and peripheral nervous systems," researchers wrote. Biller said that in cardiac surgery, there's always a risk of neurologic complications, especially in older patients who have other health problems. However, Biller said patients should not be afraid to undergo cardiac procedures. Many complications are rare. And despite the risks, cardiac surgeries generally "are highly beneficial and life saving," he said.
Study shows link between smoking, MS, and brain atrophy ... Persons with multiple sclerosis who smoked for a little as six months during their lifetime had more destruction of brain tissue and more brain atrophy than MS patients who never smoked, a study by neuroimaging specialists at the University at Buffalo has shown. Research published in the Aug. 18, 2009, issue of Neurology, the medical journal of the American Academy of Neurology (St. Paul, Minnestoa), showed that "ever-smokers" had more brain lesions and greater loss of brain volume, as well as higher scores on the Expanded Disability Status Scale (EDSS), than MS patients who had no history of smoking. The EDSS score is an average number derived from measures of various functions of the central nervous system. It is based on a scale from 0 to 10, with 10 representing greatest disability. Nonsmokers recorded an average EDSS score of 2.5, compared to 3.0 for ever-smokers. "Cigarette smoking is one of the most compelling environmental risk factors linked to the development and worsening of MS," said Robert Zivadinov, MD, PhD, UB professor of neurology, director of the Buffalo Neuroimaging Analysis Center (BNAC) where the research was conducted and first author on the study. "The biological basis of the potential link between smoking and MS has not yet been fully elucidated," Zivadinov said. "In addition to nicotine, cigarette smoke contains hundreds of potentially toxic components, including tar, carbon monoxide and polycyclic aromatic hydrocarbons."
— Compiled by Rob Kimball, MDD>