Brain
‘Scaffolding’ Protein Changes in Heart Strengthen Link Between Alzheimer’s Disease
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A team of U.S., Canadian and Italian scientists led by researchers at Johns Hopkins report evidence from studies in animals and humans supporting a link between Alzheimer’s disease and chronic heart failure, two of the 10 leading causes of death in the United States.
The international team of biochemists and cardiologists say they have identified three changes in the chemical make-up of a key structural protein, called desmin, in heart muscle cells in dogs. The changes led to the formation of debris-like protein clusters, or amyloid-like oligomers containing desmin, in heart muscle, similar to the amyloid plaques seen in the brain tissue of Alzheimer’s patients. The protein alterations, which were reversed by surgically repairing the heart, occurred at the onset of heart failure. Further experiments by the Hopkins scientists found the same chemical modifications to desmin in the heart muscle in four people already diagnosed with the disease.
Hybrid molecules show promise for exploring, treating Alzheimer’s
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One of the many mysteries of Alzheimer’s disease is how protein-like snippets called amyloid-beta peptides, which clump together to form plaques in the brain, may cause cell death, leading to the disease’s devastating symptoms of memory loss and other mental difficulties.
In order to answer that key question and develop new approaches to preventing the damage, scientists must first understand how amyloid-beta forms the telltale clumps.
University of Michigan researchers have developed new molecular tools that can be used to investigate the process. The molecules also hold promise in Alzheimer’s disease treatment. The research, led by assistant professor Mi Hee Lim, was published online this week in the Journal of the American Chemical Society.
Though the exact mechanism for amyloid-beta clump formation isn’t known, scientists do know that copper and zinc ions are somehow involved, not only in the aggregation process, but apparently also in the resulting injury. Copper, in particular, has been implicated in generating reactive oxygen species, which can cause cell damage.
Diabetics with Alzheimer’s have slower memory loss
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People who have both Alzheimer’s disease and diabetes have slower rates of memory loss than people who just have Alzheimer’s disease, French researchers said on Tuesday.
They studied 600 Alzheimer’s patients for four years and found those who had both Alzheimer’s and diabetes—about 10 percent of the total—scored far better on twice yearly memory and thinking tests than those with Alzheimer’s who did not have diabetes.
“This result was surprising,” said Dr. Caroline Sanz of the French National Institute for Health and Medical Research, whose study appears in the journal Neurology.
Treatment of severe burn injuries
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Almost three quarters of patients with extensive burns die of the consequences of a severe infection. In the current edition of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2009; 106[38]: 607-13), Timo A. Spanholtz of the Cologne-Merheim Burn Center and his coauthors discuss the acute therapy and follow-up care of burn disease.
Optimal treatment of severely burned patients necessitates collaboration between primary care physicians, emergency physicians and specialist departments for plastic surgery. During first aid from the emergency physician, the patient is removed from the danger zone and is administered adequate fluid, and drugs, over several intravenous accesses. Additional first aid measures include cooling and sterile covering of the burned skin.
The Central Office for Burn Injuries in Hamburg then organizes the necessary transfer to a specialist department.
Yale team finds mechanism that constructs key brain structure
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Yale University researchers have found a molecular mechanism that allows the proper mixing of neurons during the formation of columns essential for the operation of the cerebral cortex, they report in the Sept. 16 online issue of the journal Nature.
Scientists have known for years that information processing in the cerebral cortex depends upon groupings of neurons that assemble in the shape of vertical columns. If the number and mix of neurons in the column are wrong, severe cognitive problems can result. For instance, malformations of these columns have been implicated in some forms of autism and mental retardation. Scientists, however, have not been able to find the molecular mechanism responsible for this intermixing.
In the Nature paper, a team led by Pasko Rakic, professor and chairman of the Department of Neurobiology and head of the Kavli Institute for Neuroscience, describes one of the molecular mechanisms essential to the organizations of these key structures.
Unhealthy habits alter thinking, memory skills
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If you’re having trouble remembering where you left your keys or recalling a word, mull over the number of times and how many years you’ve continued unhealthy behaviors.
Previous research has linked declining thinking and memory skills with unhealthy behaviors such as smoking, abstaining completely from alcohol, not getting enough physical activity, and not eating enough fruits and vegetables daily.
In the current study, Dr. Severine Sabia and colleagues found the more each of the 5,123 adult participants reported these behaviors the greater their “risk of cognitive deficit,” Sabia told Reuters Health in an email.
New treatment option for ruptured brain aneurysms
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Researchers in Finland have identified an effective new treatment option for patients who have suffered a ruptured brain aneurysm, a potentially life-threatening event. Results of the new study on stent-assisted coil embolization were published today in the online edition of Radiology.
An aneurysm is a bulge or sac that develops in a weak area of a cerebral artery wall. Subarachnoid hemorrhage occurs when an aneurysm ruptures, diverting oxygen-rich blood from vital areas to the space between the brain and the skull. The ruptured vessel can be repaired surgically or through a minimally invasive procedure called embolization, in which the sac is filled with metal coils in order to prevent repeat bleeding from the aneurysm and to restore normal blood flow in the artery.
“The treatment decision is complicated in cases of acutely ruptured aneurysms,” said the study’s lead author, Olli Tähtinen, M.D., assistant professor of radiology at Tampere University Hospital in Tampere, Finland.
Strong link found between concussions and brain tissue injury
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Concussions, whether from an accident, sporting event, or combat, can lead to permanent loss of higher level mental processes. Scientists have debated for centuries whether concussions involve structural damage to brain tissue or whether physiological changes that merely impair the way brain cells function, explain this loss. Now, for the first time, researchers at Albert Einstein College of Medicine of Yeshiva University have linked areas of brain injury to specific altered mental processes caused by concussions.
The research, described in the August 26 edition of Radiology, provides compelling evidence that concussions involve brain damage. The findings suggest that diffusion tensor imaging (DTI), the brain scanning method used by the Einstein scientists, could help in diagnosing concussions and in assessing the effectiveness of treatments.
“DTI has been used to look at other brain disorders, but this is the first study to focus on concussions,” said Michael Lipton, M.D., Ph.D., associate director of the Gruss Magnetic Resonance Research Center (MRRC) and associate professor of radiology, of psychiatry and behavioral sciences, and of neuroscience at Einstein and lead author of the study. “It proved to be a powerful tool for detecting the subtle brain damage that we found to be associated with concussions.”
A Window into the Brain
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When we absorb new information, the human brain reshapes itself to store this newfound knowledge. But where exactly is the new knowledge kept, and how does that capacity to adapt reflect our risk for Alzheimer’s disease and other forms of senile dementia later in our lives?
Dr. Yaniv Assaf of Tel Aviv University’s Department of Neurobiology is pioneering a new way to track the effect of memory on brain structure. “With a specific MRI methodology called ‘Diffusion Imaging MRI,’ we can investigate the microstructure of the tissue without actually cutting into it,” he explains. “We can measure how much capacity our brain has to change structurally, what our memory reserve is and where that happens.”
His study, presented at the Annual Meeting of the Human Brain Mapping Organization in San Francisco, has been pivotal to the way scientists view the effect of memory on the brain. Scientists used to believe that the brain took days or weeks to change its microstructure. Dr. Assaf’s new observations demonstrate that the microstructure can change in mere hours.
Agent Orange linked to heart disease, Parkinson’s
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Agent Orange, used by U.S. forces to strip Vietnamese and Cambodian jungles during the Vietnam War, may raise the risk of heart disease and Parkinson’s disease, U.S. health advisers said on Friday.
But the evidence is only limited and far from definitive, the Institute of Medicine panel said.
“The report strongly recommends that studies examining the relationship between Parkinson’s incidence and exposures in the veteran population be performed,” the institute, an independent academy that guides federal policy, said in a statement.
Researchers Discover Possible Therapeutic Target to Slow Parkinson’s Disease
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University of Medicine and Dentistry of New Jersey (UMDNJ) researchers have discovered a therapeutic target that, when manipulated, may slow the progression of or halt Parkinson’s disease, a debilitating neurodegenerative disorder that affects an estimated one million people in the U.S.
A team from the Center for Neurodegenerative and Neuroimmunologic Diseases in the Department of Neurology at the UMDNJ-Robert Wood Johnson Medical School carried out the study. M. Maral Mouradian, M.D., center director and William Dow Lovett Professor of Neurology, was its lead investigator. A paper on their findings, titled “Repression of a-synuclein expression and toxicity by microRNA-7,” appears in the July 20 edition of the Proceedings of the National Academy of Sciences (PNAS).
In this publication, the investigators report that the small RNA molecule microRNA-7, which is present in neurons, directly represses the expression of a-synuclein, a protein that, in excess, proves deleterious to certain types of brain cells.
Study singles out pesticide in Parkinson’s risk
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New research provides more evidence for a link between pesticide exposure and Parkinson’s disease and pinpoints a specific risky chemical.
Dr. Jason R. Richardson of the Robert Wood Johnson Medical School in Piscataway, New Jersey, and his colleagues found that Parkinson’s disease patients were more likely to have detectable levels of beta-hexachlorocyclohexane (beta-HCH) in their blood, and also had higher average levels, than healthy individuals or Alzheimer’s disease patients.
The first evidence suggesting an association between pesticides and the degenerative brain disease Parkinson’s came out in the 1990s, but the current findings are the first to finger a specific chemical, Richardson told Reuters Health.
Most take news of genetic Alzheimer’s risk well
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Adult children who have a parent with Alzheimer’s disease may want to know if they carry a gene that raises their risk of getting the mind-robbing disease. But can they handle the test result, psychologically? Findings from a study released today hint that most can handle the information.
The e4 version of the apolipoprotein E (APOE) gene is associated with an increased risk of Alzheimer’s disease, as well as impaired memory in people without dementia and with progression to Alzheimer’s disease in people with mild thinking impairment.
In the REVEAL study, researchers found that disclosing APOE test results to adult children of patients with Alzheimer’s disease “did not result in significant short-term psychological risks.”
Study Continues to Refine Most Effective Methods to Predict Alzheimer’s Disease
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A new Mayo Clinic study found that the clinical criteria for mild cognitive impairment is better at predicting who will develop Alzheimer’s disease than a single memory test. This is one more piece of information to aid in the identification and early treatment of individuals most likely to develop Alzheimer’s disease. This study will be presented at the Alzheimer’s Association International Conference on Alzheimer’s Disease on July 14 in Vienna.
Alzheimer’s disease is a degenerative disorder of the brain in which nerve cells die over time, resulting in a steady loss of memory and other thinking abilities. An estimated 5.3 million Americans are living with Alzheimer’s disease, and it is the sixth-leading cause of death in the U.S. Mild cognitive impairment is a transitional state between normal aging and the earliest features of Alzheimer’s disease.
“The goal of this research is to try to predict who is going to develop Alzheimer’s disease in the future,” says Ronald Petersen, M.D., Ph.D., a neurologist at Mayo Clinic and the lead author of this study. “Ideally, we’d like to identify individuals before any damage is done in the brain. The sooner we intervene on this process with medications or other therapies, the greater impact we can have on lessening the number of people who will ultimately develop Alzheimer’s disease.”
New tests may help spot early-stage Alzheimer’s
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New tests assessing brain changes and body chemistry are showing promise at diagnosing Alzheimer’s disease in its earliest stages, aiding the search for new drugs, researchers said on Tuesday.
In one study, Irish researchers found scans measuring brain volume and a combination of memory tests accurately identified nearly 95 percent of people who had progressed from mild cognitive impairment to early Alzheimer’s disease.
In another study, U.S. researchers found that a type of brain scan that measures glucose combined with low scores on memory tests was a strong predictor of disease progression.
