The National Institute of Environmental Health Sciences announced five-year grants totaling $20 million for three centers to conduct research on the relationship between exposure to environmental agents and Parkinson’s disease. The Parkinson’s Institute, in Sunnyvale, California, will examine possible protective effects of tobacco and caffeine, the underlying mechanisms of dopamine cell death, and genetically determined susceptibility traits. The Emory Collaborative Center for Parkinson’s Disease Environmental Research at Emory University, Atlanta, will focus on pesticide interaction with the proteins that package dopamine within nerves and the cellular machinery that degrades abnormal proteins. The Center for Gene-Environment Studies in Parkinson’s Disease at the University of California, Los Angeles, will study how variations in genes that regulate dopamine levels within neurons may play a role in the increased risk of Parkinson’s disease associated with pesticides. The three centers will conduct their research independently but will have the benefit of acting as a consortium.

Patients with motor neuron disease were more likely than matched controls to have been slim and to have been varsity athletes, reported a study in the September 9 Neurology. The case-control study examined variables including body mass index, age at onset of disease, sex, slimness, and participation in varsity athletics of 279 patients with motor neuron disease and 152 with other neurologic diseases. Lead author Nikolaos Scarmeas, MD, of Columbia University found “the odds of having motor neuron disease was 2.21 times higher in subjects who reported they had always been slim than in those who did not. Further, motor neuron disease was 1.70 times higher in patients who reported they had been varsity athletes.” Researchers hypothesized that vigorous physical activity might increase exposure to environmental toxins, facilitate the transport of toxins to the brain, increase the absorption of toxins, or increase the athlete’s susceptibility to motor neuron disease through added physical stress.

Researchers have identified one of the key proteins involved in communication within the central nervous system, according to the August 30 Science. The team, from the University of Texas Southwestern Medical Center at Dallas, found that the protein SynCAM (synaptic adhesion molecule) plays a major role in the formation of synapses. They identified the protein by searching the mouse genome for a candidate molecule that could form a bridge between neurons and recruit synaptic components. A model was created by artificially inducing synapses using cultured neurons from laboratory mice. When SynCAM was overexpressed, the researchers reported a nearly threefold increase in spontaneous synaptic structures and activity. When this function of SynCAM was interrupted, there was a decrease in the number of synapses and activity.

Increasing the dose of the diuretic drug mannitol may double the chances of survival for patients with serious head injuries, suggested a study in the September Neurosurgery. Researchers studied the effects of mannitol in high-risk patients with head injuries and cerebral hemorrhage. The patients were randomly assigned to receive high-dose or standard-dose mannitol. After six months, 19% of patients receiving high-dose mannitol had died, compared with 36% of those receiving the usual dose. Researchers discovered that patients who did not develop abnormal pupil widening until they arrived at the hospital had the best responses to high-dose mannitol. Patients whose pupils were already widened at the accident scene did not respond as well, suggesting that starting mannitol before the patient arrives at the hospital may have benefits.

Investigators have determined that N-acetylaspartate reduction in the occipital lobe may be a marker for dementia in Parkinson’s disease. Thirty-nine subjects (14 with Parkinson’s disease and a clinical diagnosis of dementia, 12 with Parkinson’s disease, and 13 controls) were recruited for the study. The three groups underwent clinical and neuropsychological assessment, and metabolite concentrations were acquired by proton magnetic resonance spectroscopy. Researchers found that in the occipital cortex, patients with Parkinson’s disease and dementia showed significantly lower N-acetylaspartate values than did patients with Parkinson’s disease or control subjects, indicating predominant neuronal cell dysfunction or death. The investigators found no other significant differences among the three groups. The study was published in the September Archives of Neurology.

A combination of leg crossing and muscle tensing may help prevent fainting, according to a report in the September 3 rapid access issue of Circulation. Researchers evaluated these maneuvers in 20 patients who had a history of vasovagal syncope, but were otherwise healthy. Each patient reclined on a table that was rotated to a 60-degree angle and was held in that position for 20 minutes, while researchers monitored their heart rate and blood pressure. During the tilt table test, investigators told patients to begin the maneuvers when blood pressure began to fall and syncope symptoms appeared. The maneuver stabilized blood pressure and heart rate in all patients, and in five patients, fainting was prevented.

Researchers have shown that they can detect fetal brain activity in response to flashes of light transmitted through the mother’s abdomen. The investigators tested the new device, called SARA (SQUID [Superconducting Quantum Interference Device] Array for Reproductive Assessment), on 10 fetuses with a gestational age of 28 to 36 weeks and no known risk factors for brain damage. Researchers used fiber-optic cable to deliver light pulses to the outside of the mother’s abdomen while recording the magnetoencephalography data. The investigators discovered that four of the 10 fetuses had measurable brain responses to the light pulses. Researchers stressed that more testing is needed to define what types of responses indicate normal and abnormal brain activity. The study was published in the September 9 Lancet.

A study in the September 10 Neurology challenged previous findings that patients undergoing elective coronary bypass grafting experience long-term cognitive decline. The study compared the cognitive abilities of 52 patients prior to coronary bypass grafting surgery and five years after the surgery. None of the patients showed clinically significant cognitive decline, defined as a decrease of one standard deviation or more in at least two of the seven-part Wilcoxon tests. Four patients (8%) showed a decline in two of the tests. Sixteen patients (31%) had lower follow-up test scores in one of the tests, and 46 (88%) had better results in at least one test.

Investigators have discovered critical clues that may explain why parts of the brain damaged by Parkinson’s disease are not repaired by dopamine replacement therapy. By studying rats, the researchers produced the first microelectrode functional map of the sensorimotor portion of the basal ganglia in a Parkinsonian brain. They found that clusters of neurons in the basal ganglia that control specific movements became smaller in size when dopamine- deprived. “Evidence showed that around the edges of the clusters some of the neurons changed their responsiveness and were thereby excluded from their original clusters,” said Mark West, PhD, of Rutgers, the State University of New Jersey. Moreover, the connection reorganization appears to be permanent, which may explain why drugs are unable to restore behaviors. The study was published in the October 7 Journal of Comparative Neurology.

A vaccine that interferes with blood vessel inflammation greatly reduces the frequency and severity of strokes in rats, according to a study published in the September Stroke. Researchers found that exposing the rats to the protein E-selectin programs lymphocytes to monitor the blood vessel lining for the protein, producing substances that suppress inflammation. The researchers tested 113 stroke-prone rats with genetically induced hypertension. Some of the rats received a single course of E-selectin every other day for 10 days, while others received the 10-day course of treatment every three weeks until they died or until the study was complete. The rats that received the repeated E-selectin vaccine treatment had 16 times fewer ischemic strokes during the year of study than did controls. Furthermore, none of the rats given repeated vaccine treatment had a hemorrhagic stroke. The researchers are now planning a clinical trial to test the effects of the vaccine in humans at high risk for stroke.

Bone marrow cell transplants improved the recovery from stroke in animal studies, according to a report published in the August 27 Neurology. Rats treated with an intravenous transplant of adult human stromal cells had significant improvements in their ability to function 14 days after stroke, compared with rats that did not receive transplants. Bone marrow cells were taken from healthy human donors, and injected into the rats one day after stroke was induced. The rats were tested on their motor and sensory abilities and on their reflexes before the stroke and at days 1, 7, and 14 after the stroke. A detailed neurologic examination showed that 14 days after the stroke the treated rats had a 30% improvement in overall neurologic score compared with the control rats.

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