BRAIN, NOT HEART
Researchers say protein called JAM-1, which jams blood and oxygen flow to the brain, is the cause of hypertension
Brain changes before memory loss
CHICAGO
People who develop Alzheimer's disease or dementia exhibit brain-structure changes years before they show any signs of memory loss, a finding that may allow doctors to identify people at risk for the cognitive problems that lead to the devastating brain disease.
The finding is based on a small study, published in Neurology in April, that involved 136 seniors over 65 who were given brain scans and cognitive testing on a regular basis over five years. By the end of the study, 23 of the volunteers had developed mild cognitive impairment (MCI) and, of those, nine went on to develop Alzheimer's disease. The researchers found that the 23 who went on to develop memory problems had lesser gray matter in areas of the brain involved with memory processing than the 113 volunteers who did not, even when their brain function was normal.
"We found that changes in brain structure are present in clinically normal people an average of four years before MCI diagnosis," said Charles Smith, author of the study and an expert on memory and ageing at the University of Kentucky Medical Center in Lexington. "We knew that people with MCI or Alzheimer's disease had less brain volume but before now we didn't know if these brain structure changes existed, and to what degree, before memory loss begins," he said.
Moreover, the individuals who later developed memory problems had lower cognitive-test scores at the beginning of the study than the other seniors in the study, although the scores were within normal range.
"These findings of structural changes in cognitively normal people before memory loss begins aren't surprising given that Alzheimer's disease may be present for many years before symptoms of the disease begin to appear," said Smith.
Tau may hold key to Alzheimer's treatment
SAN FRANCISCO
Experiments to reduce a key brain protein in mice could lead to possible treatment options for Alzheimer's disease. The Gladstone Institute of Neurological Disease in San Francisco has found that slashing the tau protein, which regulates the internal brain skeleton, can prevent seizures, memory loss, and defects related to Alzheimer disease.
"It appears that reducing tau has a protective effect on the brain," said Lennart Mucke, director of the Gladstone Institute, which led the study, published in Science.
Researchers cut tau production in mice brains in half by inactivating one gene that produces the protein. In other mice, tau production was eliminated by inactivating both genes.
Even in mice where tau production was reduced, mice genetically engineered to develop Alzheimer's lived a normal life span and retained their memory function. Reducing tau levels also make the mice more resistant to epileptic seizures.
Much of Alzheimer's research has focused on plaques that build up in the brains of patients and are widely thought to cause the brain-wasting disease. But by reducing tau, these plaques did not have the same destructive effects.
"Reduction of tau restricts the brain a little like a restriction plate on a race car prevents the car from spiraling out of control," Mucke said.
Preliminary drug trials have been successful in reducing tau in cell cultures but no drug therapies exist that target tau levels in humans.
Brain, not heart, causes high blood pressure
LONDON
The brain-not the heart-is responsible for high blood pressure, according to a study by British researchers who said that hypertension, which can lead to heart attacks, strokes, and kidney damage, is an inflammatory vascular disease of the brain rather than the heart, as previously thought.
The research, published in Hypertension, discovered that a protein in the brain called JAM-1 trapped white blood cells, which can then cause inflammation and obstruct blood flow, leading to poor oxygen supply to the brain.
Prof. Julian Paton, from Bristol University, western England, said the findings could lead to new ways of treating the condition. "We are looking at the possibility of treating those patients that fail to respond to conventional therapy for hypertension with drugs that reduce blood-vessel inflammation and increase blood flow within the brain," he added. "The future challenge will be to understand the type of inflammation within the vessels in the brain, so we know what drug to use and how to target them. JAM-1 could provide us with new clues as how to deal with this disease."
Prof. Jeremy Pearson, associate medical director of the British Heart Foundation, said: "This exciting study is important because it suggests there are unexpected causes of high blood pressure related to blood supply to the brain. It therefore opens up the possibility of new ways to treat this common, but often poorly managed condition."
Doctors to study human anatomy on holodeck
OTTAWA
Canadian scientists have created the world's first virtual computer model of a human body, translating a litany of complex medical and genomic data into 4D images to test drugs and surgeons' skills. The virtual man with his skin and skeleton removed to display every vein, artery, and organ, floating in a small, dark room with more than 3,000 body parts projected from walls and the floor, was unveiled at the University of Calgary in western Canada.
Known as CAVEman, he is anatomically perfect and ready to be manipulated at the click of a button on a computer, holding the key to understanding complex diseases and human development, say its creators.
"The image almost comes alive," said Andrei Turinsky, a researcher at the University of Calgary's department of biochemistry and molecular biology. "It allows us for the first time to model the entire human body including anatomy, chemistry and tissue types."
Using Java 3-D technology, a commonly used web-based computer-programming language, images that can be detected with the use of special glasses allow doctors to pinpoint DNA defects and manipulate genes in a bid to find cures for diseases. This complete human atlas in four dimensions-length, width, height, and time-also allows researchers to observe the evolution of illnesses and to view the body's reaction to digital chemicals.
"A doctor or patient could be shown what is going on inside a body. For people not versed in medical terminology or medical data analysis, it helps them to see it visually," Turinsky said. "It's much better than a biology textbook. Initially, we would feed a person's medical data into the computer to show them what is happening in their body. Eventually, we hope to use it to predict what would happen if a patient didn't pursue a treatment or if certain genes act up."
The computer program could tell scientists if a drug has potential before heading into the lab to conduct tests on living cells, avoiding experiments on animals, people or cadavers before starting clinical trials. It could also be used to help doctors plan a surgery or develop new surgical techniques.
Initially, the project aimed to create computer models that could be used to train massage therapists. But researchers quickly realized its broader potential.
The 4D human atlas is built upon data from basic anatomy textbooks. Fundamental body systems and organs were rendered into animated drawings by a graphic artist, and converted into Java 3-D images to bring them to life in the university's "holodeck."
A team of computer scientists, biologists and mathematicians worked on the project for six years. Turinsky said he hopes to see it widely used within the next two years.
Vaccine developed to curb hypertension
LONDON
Scientists at a British pharmaceutical firm have developed a vaccine to curb high blood pressure, an advance over pills that cause side effects. The Daily Mail reported that Protherics in Cheshire, northwest England, has successfully tested the vaccine on people and plan to stage further tests with an improved formula, hoping to market the product within five years.
The vaccine would require just three injections with a booster every six months. The injection uses a protein found in limpets, a common shellfish, to attack angiotensin, a hormone produced by the liver that raises blood pressure by narrowing arteries. However, the vaccine turns the body's immune system against the hormone, the report newspaper said.
The company reported few side effects, although 10 percent of those who tried it complained of a brief flu-like illness.
Protherics said the drug will make it much easier for people-who have until now had to rely on pills that can cause side effects and prompt people to give up the treatment-to control their blood pressure. "Improving compliance in this way could save thousands from life-threatening complications such as heart attack or stroke," Andrew Heath, a company researcher, said.
Hoping to put its product on the market within five years, Protherics is planning trials of a new injection that is 10 times better at stimulating the immune system than its original formula, the newspaper said.
Prof. Graham MacGregor of Britain's Blood Pressure Association welcomed news of the vaccine. "If you have to take blood pressure tablets, you have to take them for the rest of your life and some people find that difficult. Finding other ways and better ways of trying to lower blood pressure without side effects would be very much welcome," he was quoted as saying.
Robot salamander helps understand spinal cord
WASHINGTON
Small steps for a robot salamander may just be a leap toward understanding spinal-cord injuries, according to a study by French and Swiss scientists. The robot can change speed and gait in response to electronic impulses, indicating that the distributed nervous function of the spinal cord may hold the key to understanding the complex locomotion of vertebrates, according to the study published in Science.
Scientists at France's University of Bordeaux and Switzerland's Ecole Polytechnique Federale de Lausanne (EPFL) created Salamandra Robotica, a four-legged yellow creature that follows the impulses of a simple computerized drive.
EPFL professor Auke Ijspeert said, "We used the robot to show that our model actually reflects reality. The robot was very useful to validate that our model could effectively modulate speed, direction and gait-aspects that need a mechanical 'body' to be properly evaluated-and also to verify that the generated movements are close to those of a real salamander."
Because the research may lead to better understanding of the human-spinal-cord circuitry, it may help remedy spinal-cord injuries.
"Nature found a nice way of making a sophisticated circuit in the spinal cord and then controlling the muscles from there," said Ijspeert. "It's a fantastic solution for coordinating multiple degrees of freedom in a simple distributed way."
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