Oil Spill Clean-up Agents Threaten Coral Reefs

Daily Science Journal (Jul. 31, 2007) — In a setback for efforts to protect endangered coral reefs from oil spills, researchers in Israel report that oil dispersants -- the best tool for treating oil spills in tropical areas --are significantly more toxic to coral than the oil they are used to clean up. Their study, which urges caution in the use of these materials, is scheduled for the August 1 issue of ACS' Environmental Science & Technology.

Oil-spill clean-up agents are a threat to coral reefs, researchers say. Credit: (Credit: Courtesy of Shai Shafir, The Hebrew University of Jerusalem)

Called the 'rainforests of the sea,' coral reefs are an endangered ecosystem and are disappearing at an alarming rate due to numerous threats, including over-fishing, global warming and pollution, particularly oil spills. Besides hosting a rich diversity of marine organisms, these habitats are also potential sources of life-saving medicines and food for humans. Scientists looking for better ways to protect this important habitat have recently focused on the environmental impact of oil dispersants, detergents used break down oil spills into smaller, less harmful droplets.

In the new report, Shai Shafir and colleagues evaluated the effects of both crude oil and six commercial oil dispersants under laboratory conditions on the growth and survival of two important species of reef corals. The dispersants and dispersed oil droplets were significantly more toxic to the coral than the crude oil itself, the scientists report. The dispersants caused "significant harm," including rapid, widespread death and delay in growth rates, to the coral colonies tested even at doses recommended by the manufacturers, they add.

"Decision-making authorities should carefully consider these results when evaluating possible use of oil dispersants as a mitigation tool against oil pollution near coral reef areas," the report said.

Article: "Short and Long Term Toxicity of Crude Oil and Oil Dispersants to Two Representative Coral Species"

Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

A Blueprint For 'Smart' Health Care

Daily Science Journal (Jul. 30, 2007) — Always on, connected, cheap and on sale everywhere.

A cell phone displays a patient's health information in this photo illustration of new technology for providing smart health care announced recently by the University of Florida and IBM. (Credit: Image courtesy of University of Florida)

What people have come to expect in cell phones and personal communicators may soon become common in health-care devices and products at home and in medical offices, thanks to new technology announced recently by the University of Florida and IBM.

The technology creates the first-ever roadmap for widespread commercial development of "smart" devices that, for example, take a person's blood pressure, temperature or respiration rate the minute a person steps into his or her house -- then transmit it immediately and automatically to doctors or family.

That could eliminate the need for many doctor's visits, which are often difficult for the elderly or sick. By enabling regular updates via text message or e-mail, the technology also could pave the way for people to share real-time information on their health or well-being with absent loved ones. And it could prove useful for doctors who need to keep tabs on many patients at one time by helping the doctors to prioritize whom to treat first.

"We call it quality-of-life engineering," said Sumi Helal, professor of computer engineering and the project's lead UF researcher. "It's really a change of mindset."

The idea of using technology to provide medical care at a distance is nothing new. Doctors have relied on "telemedicine" to communicate with specialists for years. More recently, telemedicine has been expanded to include, for example, surgeons performing robotic procedures on distant patients.

But the UF-IBM advance goes a step further: It provides the technological "stepstones" to make it easy for any company to manufacture and sell smart networked devices -- while also making them more user-friendly for consumers.

"UF and IBM both see the need and the opportunity to integrate the physical world of sensors and other devices directly into enterprise systems," said Richard Bakalar, Chief Medical Officer for IBM. "Doing so in an open environment will remove market inhibitors that impede innovation in critical industries like health care and open a broader device market that's fueled by uninterrupted networking."

Helal has devoted the past several years to developing smart devices for the elderly in a model home known as the "Gator Tech Smart Home" in Gainesville.

He and his students pioneered the "Smart Wave" microwave oven that can automatically determine how much time to cook a frozen meal or keep track of how much salt it contains. Among other devices, they also created an instrument that records how many steps a person takes, information that can tell absent caregivers how active its occupants are.

But these and other devices currently have a major shortcoming: They require "a team of engineers" to install them, Helal said. In a world where consumers are accustomed to electronics that require no more than a power outlet, that dramatically limits their appeal. "We decided to create a technology that self integrates," Helal said. "When you bring it in to the house and plug it in, it automatically provides its service and finds a path to the outside world."

With $60,000 in research funding from IBM, Helal designed "middleware," or software and hardware that glues together different systems, that can give his and any similar health-aid devices this independence and connectivity. Importantly, the software is based on open standards, or publicly available specifications useable by anyone, such as those now being made available by consortiums of technology companies including Eclipse, W3C and OSGi.

Open standards make it easy for product developers to tap the technology in any new smart assistive devices, Helal said. That, in turn, will make the devices more common.

The hardware component of the system is an inexpensive sensor platform about half the size of a business card. Developed at UF and licensed to Pervasa, a Gainesville-based UF spinoff company headed by Helal, the "Atlas" platform makes it easy to create a network of sensors and make their information available on a computer network.

The advance is crucial given the increasing number of elderly Americans. The number of people 85 and over is expected to rise from 4.2 million in 2000 to 6.1 million in 2010 and 9.6 million by 2030, according to federal government statistics. Meanwhile, the percentage of older Americans living alone will either remain high or continue to grow: About half of women and nearly a quarter of men aged 75 and older currently live alone.

But the UF-IBM technology may also prove useful in many other medical settings. For example, Helal said, it could help emergency rooms operate more safely. Rather than a standard waiting list, patients could be equipped with networked wireless monitors of their vital signs, allowing doctors to determine who in a waiting room needs the most immediate care.

Adapted from materials provided by University of Florida.

Read the rest of this entry »

Frequent Brain Stimulation In Old Age Reduces Risk Of Alzheimer's Disease

Daily Science Journal (Jul. 28, 2007) — How often old people read a newspaper, play chess, or engage in other mentally stimulating activities is related to risk of developing Alzheimer's disease, according to a new study.

For the study, more than 700 people in Chicago, IL, with an average age of 80 underwent yearly cognitive testing for up to five years. Participants were part of the Rush Memory and Aging Project, a longitudinal study of more than 1,200 older people. Of the participants, 90 developed Alzheimer's disease. Researchers also performed a brain autopsy on the 102 participants who died.

The study found a cognitively active person in old age was 2.6 times less likely to develop dementia and Alzheimer's disease than a cognitively inactive person in old age. This association remained after controlling for past cognitive activity, lifetime socioeconomic status, and current social and physical activity.

Researchers say the findings may be used to help prevent Alzheimer's disease.

"Alzheimer's disease is among the most feared consequences of old age," said study author Robert S. Wilson, PhD, with the Rush Alzheimer's Disease Center at Rush University Medical Center in Chicago. "The enormous public health problems posed by the disease are expected to increase during the coming decades as the proportion of old people in the United States increases. This underscores the urgent need for strategies to prevent the disease or delay its onset."

Wilson says the study also found frequent cognitive activity during old age, such as visiting a library or attending a play, was associated with reduced risk of mild cognitive impairment, a transitional stage between normal aging and dementia, and less rapid decline in cognitive function.

This research was published June 27, 2007, in the online edition of Neurology®, the medical journal of the American Academy of Neurology.

The study was supported by grants from the National Institute on Aging and the Illinois Department of Public Health.

Adapted from materials provided by American Academy of Neurology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

NASA'S Swift Sees Double Supernova In Galaxy

Daily Science Journal (Jun. 27, 2007) — In just the past six weeks, two supernovae have flared up in an obscure galaxy in the constellation Hercules. Never before have astronomers observed two of these powerful stellar explosions occurring in the same galaxy so close together in time.

Supernova 2007ck (left) is a Type II event, and Supernova 2007co (right) is a Type Ia event. The image is a combination of red, green, and blue pictures taken on June 9 and 12 by the Ultraviolet/Optical Telescope on NASA’s Swift satellite, which was designed primarily to study another type of stellar explosion – gamma ray bursts. (Credit: Stefan Immler NASA/GSFC, Swift Science Team.)

The galaxy, known as MCG +05-43-16, is 380 million light-years from Earth. Until this year, astronomers had never sighted a supernova popping off in this stellar congregation. A supernova is an extremely energetic and life-ending explosion of a star.

Making the event even more unusual is the fact that the two supernovae belong to different types. Supernova 2007ck is a Type II event – which is triggered when the core of a massive star runs out of nuclear fuel and collapses gravitationally, producing a shock wave that blows the star to smithereens. Supernova 2007ck was first observed on May 19.

In contrast, Supernova 2007co is a Type Ia event, which occurs when a white dwarf star accretes so much material from a binary companion star that it blows up like a giant thermonuclear bomb. It was discovered on June 4, 2007. A white dwarf is the exposed core of a star after it has ejected its atmosphere; it’s approximately the size of Earth but with the mass of our Sun.

"Most galaxies have a supernova every 25 to 100 years, so it’s remarkable to have a galaxy with two supernovae discovered just 16 days apart," says Stefan Immler of NASA’s Goddard Space Flight Center. In 2006 Immler used NASA’s Swift satellite to image two supernovae in the elliptical galaxy NGC 1316, but both of those explosions were Type Ia events, and they were discovered six months apart.

The simultaneous appearance of two supernovae in one galaxy is an extremely rare occurrence, but it’s merely a coincidence and does not imply anything unusual about MCG +05-43-16. Because the two supernovae are tens of thousands of light-years from each other, and because light travels at a finite speed, astronomers in the galaxy itself, or in a different galaxy, might record the two supernovae exploding thousands of years apart.

Adapted from materials provided by NASA/Goddard Space Flight Center.

Read the rest of this entry »

Interactive Social Robots To Participate In Annual Mobile Robot Challenge

Daily Science Journal (Jul. 26, 2007) — PITTSBURGH - Grace and George, a pair of socially skilled robots developed by a team of researchers from Carnegie Mellon University, the Naval Research Laboratory and Swarthmore College, will participate in the American Association for Artificial Intelligence (AAAI) annual Mobile Robot Competition and Exhibition July 27-29, at the San Jose Convention Center in San Jose, Calif.

GRACE, shown above, is a B21R Mobile Robot built by RWI. She has an expressive face on a panning platform as well as a large array of sensors. The sensors include a microphone, touch sensors, infrared sensors, sonar sensors, a scanning laser range finder, a stereo camera head on a pan-tilt unit, and a single color camera with pan-tilt-zoom capability. GRACE can speak using a high-quality speech synthesizer, and understand responses using her microphone and speech recognition software. (Photo courtesy of Carnegie Mellon University)

Grace and George are six-foot-tall, socially adept, autonomous talking robots with digitally animated faces. The robots will work as a team to complete AAAI's Open Interaction Task, which involves interacting with conference attendees in an unstructured environment.

Grace will "work" at a booth, communicating information about the conference and schedule, while George circulates among the crowd, interacting with people, answering their questions and escorting them to conference locations. Grace will contact George and schedule times for "him" to meet and escort people to various locations. Those being escorted will put on a specially colored hat, and George will lead them to their destinations.

Though the robots have participated in AAAI's challenge since 2002, their role in this year's conference poses a new challenge.

"Having George and Grace operating throughout the conference ? not just for an hour, but working throughout the duration ? is more of a challenge," said project coordinator Reid Simmons, research professor in Carnegie Mellon's Robotics Institute. "We're pushing for a sustained presence by the robots so people can interact with them at their leisure."

He added that the group chose to participate in Open Interaction Task instead of the Robot challenge because they wanted to showcase the human-robot interaction focus of the Grace and George project.

Grace competed in AAAI's Robot Challenge in 2002 where she acted as a conference attendee. She managed to find her way to the registration booth at the Edmonton Convention Center, Alberta, Canada, register for the conference, navigate to an elevator, and find the third-floor conference room where she gave a PowerPoint presentation about herself.

At future conferences, Simmons says the team will continue to focus on human-robot interaction, with hopes of developing reliable speech recognition and creating robots that would fill the role of volunteer workers at the conference.

For more information on Grace and George, see http://www.ri.cmu.edu/projects/project_522.html.

For more information on AAAI and the Robot Challenge, see http://www.aaai.org.

Adapted from materials provided by Carnegie Mellon University.

Read the rest of this entry »

Portable Tech/Emory Device Checks For Concussions

Daily Science Journal (Jul. 25, 2007) — ATLANTA (April 26, 2005) -- A player just took a hard knock to the head and is lying on the field. A coach rushes to his side, but the player sits up and seems fine.

Biomedical Engineering Assistant Professor Michelle LaPlaca demonstrates DETECT with the help of Bryan Williams. The device helps quickly detect mild concussions in virtually any setting. (Image courtesy of Georgia Institute Of Technology)

He knows who the president is and how many fingers the coach is holding up. But is he ready to get back in the game?

More than 750,000 mild traumatic brain injuries (mTBI) occur in the United States each year. When a player or soldier with even a mild concussion is sent back to the field, another blow to the head can lead to additional life long problems or even second impact syndrome, which has a mortality rate of up to 50 percent. But the injury is difficult to diagnose, even with a quiet room and a several-hour-long test.

Michelle LaPlaca, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, and David Wright, assistant director of Emory University's Emergency Medicine Research Center, have developed a new device to detect brain injuries right on the sidelines of a football game, on a battlefield or in the emergency room.

Called DETECT (Display Enhanced Testing for Concussions and mTBI system), the device is a fast, easy to administer and sensitive system for assessing problems associated with concussions. The DETECT device is an integrated system that includes software applications, a portable computer and an LCD display in the headgear.

While a typical mTBI test requires a quiet room and 1-2 hours of testing, DETECT performs neuropsychological tests in an immersive environment in about 7 minutes, regardless of surrounding noise and movement. So, a football player or soldier who just took a hard hit to the head can take the test and either be safely cleared to get back on the field or sent to receive medical attention.

The device blocks external stimuli that could interfere with testing, such as light and sound. This allows the test to be given in virtually any setting, even a bright football field with a roaring crowd.

When suffering from mTBI, a person will have difficulty with certain types of thinking controlled by a different areas of the brain, such as working memory, complex reaction and multi-tasking. DETECT runs the wearer through three types of neuropsychological tests that measure the function of several parts of the brain as it attempts to perform the tests.

For example, the first shows the wearer a series of shapes with different colors and textures and gives voice instructions. The wearer uses a simple controller similar to a video game controller to respond to the commands. The device then measures the wearer's response times and answer selections. If the response time is too slow or the incorrect answers were provided, it indicates impairment.

The DETECT system includes a laptop to run the software, a head-mounted display, earmuffs that also act as headphones and an input device (controller). The display projects the visual aspect of the test, the headphones provide the verbal instructions and the controller records the wearer's response.

In addition to the advantages of its speed and portability, DETECT can also be administered by a non-medical personnel such as a coach or parent rather than a trained neurophysiologist.

While the device has already been tested in the lab and in a hospital emergency room, the Georgia Tech football program recognizes the need for improved concussion assessment and plans to test this new technology.

DETECT may have other potential cognitive testing applications, such as helping assess cognitive impairment related to Alzheimer's disease or drug use. The test would be brief and could be performed in a general physician's office.

DETECT is expected to be commercially available in the next three to five years.

Adapted from materials provided by Georgia Institute Of Technology.

Read the rest of this entry »

New Chemical Effective Against Anthrax

Daily Science Journal (Jul. 23, 2007) — Scientists have identified a chemical that could be used as a new drug against anthrax.

Anthrax is a deadly disease caused by spores that germinate into bacteria, which then release a deadly toxin. Spores that are inhaled by animals or people germinate in the lungs to form bacteria, which then spread throughout the body, releasing the toxin and triggering the disease. Since spore germination is needed to cause infection, preventing germination is a potentially efficient way to stop the infection.

Jurgen Brojatsch, Ernesto Abel-Santos, and colleagues identified seven chemicals that block the germination of cultured anthrax spores. They also showed that one of these compounds, 6-thioguanosine, blocked the spores' germination inside mammalian cells, thus blocking anthrax infection. The scientists are now planning to test 6-thioguanosine in mice infected with the anthrax bacterium. This compound is a known anticancer agent with well-studied pharmacological properties, which could help save time and money if it is used in clinical trials.

Article: "Identification of an in Vivo Inhibitor of Bacillus anthracis Spore Germination" by Monique Akoachere, Raynal C. Squires, Adel M. Nour, Ludmyl Angelov, Jurgen Brojatsch, and Ernesto Abel-Santos

Adapted from materials provided by American Society for Biochemistry and Molecular Biology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Treatment Causes Short-term, Modest Delay In Alzheimer's Onset In Patients With Mild Cog Impairment

Daily Science Journal (Jul. 20, 2007) — ROCHESTER, Minn. -- For the first time, a drug appears to have a slowing effect -- though limited -- on the progression from mild cognitive impairment, a memory disorder considered a strong early predictor of Alzheimer's disease, to Alzheimer's.

This randomized, double-blind, placebo-controlled, multicenter study compared vitamin E; donepezil, an Alzheimer's treatment drug; and placebo for delay or prevention of progression to Alzheimer's disease in mild cognitive impairment patients. The study's results will be presented at the 9th International Conference on Alzheimer's Disease and Related Disorders in Philadelphia on Sunday, July 18. The Alzheimer's Association described the trial as "among the most anticipated studies" to be presented at the conference.

"This is the first study to demonstrate any positive treatment effect on mild cognitive impairment with respect to progression to Alzheimer's disease," says Ronald Petersen, M.D., Ph.D., Mayo Clinic neurologist and lead investigator of the trial. "We are optimistic because this means we have begun to make progress toward delaying the development of Alzheimer's disease and the cognitive decline that accompanies it."

The study investigators report that vitamin E did not have an effect on slowing the progression to Alzheimer's disease. However, over the first half, or 18 months, of the three-year trial, mild cognitive impairment patients treated with donepezil had a reduced risk of progressing to Alzheimer's disease compared to patients who took placebo; the average delay in disease progression was about six months in those subjects who progressed to Alzheimer's disease. Although the patients treated with donepezil initially progressed to Alzheimer's disease at a slower rate than patients treated with vitamin E or placebo, this risk-reduction effect was short term. By the end of the study, the risk of progression to Alzheimer's disease was the same among all three treatment groups.

"Donepezil appeared to exert its effect during the first half of the study," says Dr. Petersen. "There were a lot of complicating factors, however, and there was no overall risk reduction effect of donepezil by the end of the study. It looks like donepezil had a time-limited, modest effect."

The investigators do not know exactly why donepezil's effect dropped off over time. Theories are that the drug's effect wore off after 18 months, or that the drug exerts a modest effect and then the disease process outweighs the chemical effect of the drug, indicates Dr. Petersen.

Previous studies show that without treatment, about 10 to 15 percent of individuals with mild cognitive impairment progress to Alzheimer's disease each year. Not every patient with mild cognitive impairment will progress to Alzheimer's disease, however.

During the three-year study, the trial participants developed Alzheimer's disease at a rate of 13 percent per year. Among those who progressed to Alzheimer's disease, patients treated with donepezil averaged 661 days until diagnosed with Alzheimer's disease, while those treated with vitamin E averaged 540 days until Alzheimer's diagnosis and those treated with placebo averaged 484 days to Alzheimer's disease.

Due to the complexity of the study's results, the investigators point out that more analysis will be critical to assess the practical implications of the new information and make recommendations for clinical practice.

This study involved 769 participants at 69 medical centers in the United States and Canada. All participants met established criteria for mild cognitive impairment and were randomized to receive vitamin E, donepezil or placebo treatment. Patients who received donepezil were given 5 mg per day for the initial six weeks and then 10 mg till the study's end, and those treated with vitamin E were given 1000 IU per day for the first six weeks and then 2000 IU per day until the study's end. The other participants were given an inactive pill, or placebo. The investigators designed the study to compare the rate of progression from mild cognitive impairment to Alzheimer's disease in each participant group.

The FDA has not approved any treatments for mild cognitive impairment. Vitamin E and donepezil were selected for testing because vitamin E has been shown to delay disease progression in Alzheimer's disease patients and donepezil relieves symptoms of Alzheimer's disease, according to Brad Boeve, M.D., also a Mayo Clinic neurologist and a co-investigator of the trial.

According to the investigators, patients who have mild cognitive impairment have memory impairment that is out of proportion to that expected for their age, yet they do not meet commonly accepted criteria for Alzheimer's disease or other types of dementia. These patients are in a transitional state between early aging and Alzheimer's disease. They can think and reason well, but recent memory is deficient for their age. Researchers have also found that those who have mild cognitive impairment show brain volume loss in the hippocampus, the area of the brain that controls the sorting, storage and recall of information. The condition can be diagnosed on the basis of five criteria:

* Memory complaints

* Abnormal memory for age

* Ability to carry out normal activities of daily living

* Normal general cognitive function

* Lack of dementia

-------

The National Institute on Aging funded this study, with additional support from Pfizer, Eisai and DSM Nutritional Products.

Adapted from materials provided by Mayo Clinic.

Read the rest of this entry »

Cluster Hits The Magnetic Bull's-eye

Daily Science Journal (Jul. 19, 2006) — The European Space Agency's spacecraft constellation Cluster has hit the magnetic bull's-eye. The four spacecraft surrounded a region within which the Earth’s magnetic field was spontaneously reconfiguring itself.

This artist's impression shows the four Cluster spacecraft encompassing a 'magnetic null' region. A magnetic null region is a three dimensional zone where the magnetic fields break and reconnect. (Credits: Dr. Xiao/Chinese Academy of Sciences (Beijing))

This is the first time such an observation has been made and gives astronomers a unique insight into the physical process responsible for the most powerful explosions that can occur in the Solar System: the magnetic reconnection.

When looking at the static pattern of iron filings around a bar magnet, it is difficult to imagine how changeable and violent magnetic fields can be in other situations.

In space, different regions of magnetism behave somewhat like large magnetic bubbles, each containing electrified gas known as plasma. When the bubbles meet and are pushed together, their magnetic fields can break and reconnect, forming a more stable magnetic configuration. This reconnection of magnetic fields generates jets of particles and heats the plasma.

At the very heart of a reconnection event, there must be a three dimensional zone where the magnetic fields break and reconnect. Scientists call this region the null point but, until now, have never been able to positively identify one, as it requires at least four simultaneous points of measurements.

On 15 September 2001, the four Cluster spacecraft were passing behind the Earth. They were flying in a tetrahedral formation with separations between the spacecraft of over 1 000 kilometres. As they flew through the Earth’s magnetotail, which stretches out behind the night-time side of our planet, they surrounded one of the suspected null points.

The data returned by the spacecraft have been extensively analysed by an international team of scientists led by Dr. C. Xiao from Chinese Academy of Sciences, Prof. Pu from Peking University, Prof. Wang from Dalian University of Technogy. Xiao and his colleagues used the Cluster data to deduce the three-dimensional structure and size of the null point, revealing a surprise.

The null point exists in an unexpected vortex structure about 500 kilometres across. "This characteristic size has never been reported before in observations, theory or simulations," say Xiao, Pu and Wang.

This result is a major achievement for the Cluster mission as it gives scientists their first look at the very heart of the reconnection process.

Throughout the Universe, magnetic reconnection is thought to be a fundamental process that drives many powerful phenomena, such as the jets of radiation seen escaping from distant black holes, and the powerful solar flares in our own Solar system that can release more energy than a billion atomic bombs.

On a smaller scale, reconnection at the dayside boundary of the Earth’s magnetic field allows solar gas through, triggering a specific type of aurora called 'proton aurora'.

Understanding what sparks magnetic reconnection will also help scientists trying to harness nuclear fusion for energy production. In tokamak fusion reactors, spontaneous magnetic reconfigurations rob the process of its controllability. By understanding how magnetic fields reconnect, fusion scientists hope to be able to design better reactors that prevent this from taking place.

Having identified one null point, the team now hopes to score future bull’s-eyes to compare nulls and see whether their first detection possessed a configuration that is rare or common.

Adapted from materials provided by European Space Agency.

Read the rest of this entry »

New Study Shows That Most Older People With Mild Cognitive Impairment Have Alzheimer’s Disease Or Cerebral Vascular Disease

Daily Science Journal (Jul. 17, 2007) — CHICAGO - Mild cognitive impairment in older people is not a normal part of growing old but rather appears to be an indicator of Alzheimer's disease or cerebral vascular disease, according to a study published in the March 8 issue of the journal, Neurology.

"The study shows that mild cognitive impairment is often the earliest clinical manifestation of one or both of two common age-related neurologic diseases," said Dr. David A. Bennett, director of the Rush Alzheimer's Disease Center at Rush University Medical Center and the principal author of the paper. "From a clinical standpoint, even mild loss of cognitive function in older people should not be viewed as normal, but as an indication of a disease process," said Bennett.

This is the first study involving a large number of subjects who were followed until they developed mild cognitive impairment or dementia, and then died.. The study involved examining brain tissue from 180 people, including 37 with mild cognitive impairment, 60 without cognitive impairment, and the rest with dementia. All were Catholic nuns, priest or brothers who agreed to participate in the National Institute on Aging (NIA) funded Religious Orders Study. Since 1993 more than 1000 persons have agreed to annual clinical evaluations and to donate their brains to the Rush investigators at the time of death.

Study participants took tests of memory, language, attention and other cognitive abilities each year to document their clinical status. The diagnosis of mild cognitive impairment (MCI) was made when impaired performance on these tests was not severe enough to warrant a diagnosis of dementia. After death, the investigators measured the amount of Alzheimer's disease pathology and cerebral infarcts (strokes) through brain autopsy. Of the 37 individuals with MCI, more than half (23) met pathologic criteria for Alzheimer's disease, and nearly a third (12) had cerebral infarcts (this include five with both). Less than a quarter (9) did not have either pathology.

"Because most people with mild cognitive impairment progress to dementia, it has been difficult to obtain brain tissue from persons who die while they still have the condition," said Bennett. "We now know that both clinically and pathologically, mild cognitive impairment patients are in the middle in terms of the disease process for Alzheimer's disease and cerebral vascular disease," said Bennett.

One positive finding from the study is that one-third (60) of the total study participants with an average age of 85 did not experience cognitive decline over several years of follow-up. Yet, about half of these persons had significant Alzheimer's disease pathology and nearly a quarter had cerebral vascular disease. "It is likely that these individuals have some type of 'reserve' capacity in their brains that allows them to escape the loss of memory despite the accumulation of pathology," said Bennett.

Bennett and his colleagues are involved in another NIA funded study at Rush, the Memory and Aging Project, trying to identify what keeps these individuals from becoming impaired. "Preventing the accumulation of disease pathology is a common approach to disease prevention," said Bennett. "Another way to prevent loss of cognition is to identify factors that protect us from becoming forgetful despite this pathology.

"From a public health perspective, the number of people with cognitive loss due to Alzheimer's disease and cerebral vascular disease is probably much larger than current estimates," said Bennett. He hopes that these data provide additional impetus to research efforts to develop treatments and, ultimately, prevention for these common diseases of aging.

The study is funded by the National Institute on Aging.

Adapted from materials provided by Rush University.

Read the rest of this entry »

Diamonds Unlikely In Gas Giants Like Uranus

Daily Science Journal (Jul. 16, 2007) — A new study finds that diamonds probably don't crystallize in the atmospheres of planets such as Uranus and Neptune. The conclusion is contrary to recent speculation that small diamonds would spontaneously form in carbon rich layers of the gas giant planets. White dwarf stars, according to the study, are veritable diamond factories.

A simulated snapshot of crystallizing carbon atoms under Uranus-like conditions. (Credit: L. M. Ghiringhelli, C. Valeriani, E. J. Meijer and D. Frenkel, Physical Review Letters)

Physicists at the Universtiet van Amsterdam and the FOM Institute for Atomic and Molecular Physics in the Netherlands performed a numerical analysis showing that at the temperatures and pressures in gas giant planets like Uranus, arrangements of carbon atoms would be much more suitable for creating tiny bits of graphite rather than diamond.

In white dwarfs, on the other hand, the simulation shows that the conditions would cause the carbon atoms to line up in configurations that are much more amenable for diamond crystallization. The conclusion is consistent with the 2004 discovery of a cooling white dwarf star that appears to have a solid diamond core 4000 kilometers across.

Although diamond formation in the atmospheres of gas giants is not strictly impossible, the Dutch physicists say that the odds are exceedingly slim that a diamond could have formed under the conditions that exist in Uranus in the entire lifetime of the universe.

Adapted from materials provided by American Physical Society, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Urine Test Predicts Alzheimer's Disease

Daily Science Journal (Jul. 14, 2007) — (Philadelphia, PA) – A urine sample taken at the doctor's office can be the step in determining your chances of developing Alzheimer's disease (AD), according to researchers at the University of Pennsylvania School of Medicine. They have determined that a urine test can reliably detect free radical damage associated with people with Mild Cognitive Impairment (MCI) – a recognized precursor to AD. The test detects isoprostanes, fatty acids that are formed as the result of free radical damage in the brain – damage that correlates with clinical diagnosis of AD.

"This is the first noninvasive test that can predict a clinical diagnosis of Alzheimer's disease," said Domenico Praticò, MD, assistant professor in Penn's Department of Pharmacology. "Since there is no cure for Alzheimer's disease, physicians could slow the course of the disease if it is caught early enough."

Within four years of initial diagnosis, up to 50% of people with MCI develop Alzheimer's disease. As AD progresses, it attacks the brain and causes severe damage in the areas important for memory, judgement, and language. This destruction leads to other clinical complications and, eventually, death.

In the study, published in the June edition of Archives of Neurology, Praticò and his colleagues measured isoprostane in blood and urine samples obtained from 50 patients with a clinical diagnosis of AD, 33 patients with MCI, and 40 healthy volunteers. Two weeks later, a CSF sample and a second urine sample were taken from 28 of the AD patients, 17 of the MCI patients, and 18 of the control subjects. The researchers found significantly higher levels of isoprostane in CSF, blood, and urine of MCI and AD subjects than in the volunteers. Remarkably, the samples taken from the MCI subjects and the volunteers differed only in respect to their isoprostane levels.

"We found that patients with MCI have increased brain oxidative damage before the onset of AD – damage that can be detected in the form of isoprostanes in urine, as this study shows," said Praticò. "In fact, five MCI subjects, all with high isoprostane levels, converted to AD during follow-up."

Patients that are diagnosed with Mild Cognitive Impairment typically present their physicians with persistent memory loss that is not normal for someone of their age and education. Although their memory is impaired, MCI patients are capable of living largely independent lives. At this stage, it is difficult to determine whether a person with MCI will eventually have Alzheimer's or whether they will progress to a form of unrelated dementia.

A urine sample taken in the doctor's office may be a first point of decision in gauging the risk of developing AD. Further tests could then determine the severity of a patient's condition and course of treatment. For example, studies have shown that the transition from MCI to AD occurs fastest in people who have a gene called apoE4 and whose brain's hippocampus region is shown to be smaller as measured in an MRI scan.

"One hypothesis is that, in AD, healthy brain tissue is damaged by the local formation of large amounts of free radicals," said Praticò. "Isoprostanes are the byproducts of fats in the human body that were warped by free radical attack. They then accumulate in CSF, blood, and urine as the body works to get rid of them."

While at the moment this test is not yet clinically available, the team is working on the development of a version of it that could be broadly and easily performed.

Unlike a spinal tap, a urine test is simple to do and provides a painless and noninvasive way of assessing the situation. "The advantages are clear: with an easier test, doctors can diagnose the disease sooner and respond better to the patient's needs," said Praticò.

This research was supported by grants from the National Institutes of Health and the American Heart Association. Trial participants were selected at the Memory Disorders Clinic of Penn's Alzheimer's Disease Center.

Adapted from materials provided by University Of Pennsylvania Medical Center.

Read the rest of this entry »

Distress-prone People More Likely To Develop Memory Problems

Daily Science Journal (Jul. 12, 2007) — People who are easily distressed and have more negative emotions are more likely to develop memory problems than more easygoing people, according to a new study.

In the study, those who most often experience negative emotions such as depression and anxiety were 40 percent more likely to develop mild cognitive impairment than those who were least prone to negative emotions. Mild cognitive impairment is a transitional stage between normal aging and dementia. People with mild cognitive impairment have mild memory or cognitive problems, but have no significant disability.

Researchers analyzed the results from two larger studies, the Religious Orders Study and the Memory and Aging Project, which involved 1,256 people with no cognitive impairment. During up to 12 years of follow-up, 482 people developed mild cognitive impairment. Participants were evaluated on their level of proneness to distress and negative emotions by rating their level of agreement with statements such as "I am not a worrier," "I often feel tense and jittery," and "I often get angry at the way people treat me."

"People differ in how they tend to experience and deal with negative emotions and psychological distress, and the way people respond tends to stay the same throughout their adult lives," said study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago, IL. "These findings suggest that, over a lifetime, chronic experience of stress affects the area of the brain that governs stress response. Unfortunately, that part of the brain also regulates memory."

An earlier study by Wilson and his colleagues showed that people who are easily distressed are more likely to develop Alzheimer's disease than more easygoing people.

Wilson said several factors lead researchers to believe that proneness to stress is a risk factor for memory problems and not an early sign of disease. For example, while the level of distress does not appear to increase in old age, the changes in the brain related to memory problems and Alzheimer's disease do increase with age.

This research was published in the June 12, 2007, issue of Neurology®, the scientific journal of the American Academy of Neurology. The study was supported by grants from the National Institute on Aging and the Illinois Department of Public Health.

Adapted from materials provided by American Academy of Neurology.

Read the rest of this entry »

Cosmetic Surgery Techniques Can Enhance Thyroid Surgery Results

Daily Science Journal (Jul. 11, 2007) — Cosmetic surgery techniques, such as having a patient sit or stand while incision sites are marked so they blend into natural lines of the body, can improve the aesthetic result of thyroid surgery as well, researchers say.

Dr. David Terris, a pioneer in minimally invasive techniques that have dramatically reduced the size of the hallmark base-of-the-neck incisions. (Credit: Image courtesy of Medical College of Georgia)

"We have found that while keeping the management of the underlying thyroid problem as the first priority, we can still achieve a maximal cosmetic result," says Dr. David Terris, a pioneer in minimally invasive techniques that have dramatically reduced the size of the hallmark base-of-the-neck incisions.

Dr. Terris, who chairs the Medical College of Georgia Department of Otolaryngology-Head and Neck Surgery, wanted to know if cosmetic surgery principles he learned in the facial plastic surgery part of his training could further improve results.

He did a prospective analysis of 248 patients who required varying approaches to thyroid surgery, from a standard, several-inch-long neck incision to remove huge thyroids to minimally invasive techniques that cut the incision size in half to endoscopic approaches that reduce incision size half again. Patients were operated on at MCG Medical Center between September 2003 and June 2006.

Most thyroid patients requiring surgery are women – 198 women compared to 50 men in this new study published in the July issue of The Laryngoscope – and many are concerned with the cosmetic result, says Dr. Terris. "It matters to them how big the scar is, if it's even, if it's hidden in a skin crease, if the edges are nicely aligned."

All patients sat up to have their incision sites marked. "You want the incision to be in a location that corresponds to a cosmetically favorable area when you are upright at a dinner party, not stretched out on an operating room table," says Dr. Terris.

Other techniques applied included:

• Trimming traumatized edges at the incision sites. "Especially with the minimal-access techniques, the idea is to customize the incision to the size of the disease rather than one size fits all, which is how thyroid surgery was done just five or six years ago, with a big incision for everybody," says Dr. Terris. "Sometimes we still make big incisions, but more often, we make a smaller incision just big enough to get the thyroid out." Skin edges sometimes get frayed as surgeons remove large nodules from relatively small incisions. "Rather than make a bigger incision, we excise that edge so you have nice, fresh dges that come together quite well."
• Using surgical glues instead of sutures. "You can line up edges and get them accurately apposed without any risk of railroad-tracking using the glue," he says, referencing tracks left by traditional sutures or staples. "It's also convenient for patients because they don't have to come back on a certain date to get the stitches removed; they just peel it off."
• Minimizing trauma to surrounding skin. "The conventional way to get to the thyroid gland is to raise up the skin to the hyoid bone above the Adam's apple and down to the clavicles, then start working on the muscles in the throat that surround the thyroid gland, separate those, then get down to the gland." But all that raising of tissue, called flaps, means hoping it will lie back down as it's supposed to. "What we recognized is that you don't need to raise those flaps all the way up and all the way down. We make our incision, we go right down to the muscles, separate them, do the work we need to do, then close them. It saves time during surgery, it saves dissection and we are not creating a big space that we hope sticks back down."
• Minimizing use of drains. Drains to manage post-surgery oozing have been used pretty much since thyroid surgery was invented. "It used to be common, rather than removing the entire thyroid, to leave a little rind, if you will, of the thyroid behind," says Dr. Terris. The hope was the remaining tissue might reduce or even eliminate the need for thyroid medicine afterward. The reality is the patients ended up on medicine and the rind often caused oozing and sometimes recurrent disease. Now doctors take out the whole thyroid or all of one side, depending on the extent of the disease. Also today, minimally invasive techniques and other surgical improvements such as the thin, ultrasonic harmonic scalpel, have reduced overall surgical trauma. In the study, only 111 of the 248 patients got drains, 60 of whom had conventional thyroidectomy.

Researchers reported that only one of the 248 patients required additional treatment for their surgery scar; she received steroid injections for hypertrophic scarring.

"Although there continues to be enthusiasm for the use of these smaller incisions to accomplish thyroid surgery, it is likely that the application of well-known cosmetic principles is equally important to achieving optimal outcomes," Dr. Terris and his co-authors write.

Adapted from materials provided by Medical College of Georgia.

Read the rest of this entry »

Stellar Tiramisu: Astronomers Find Hints of Distant Planetary Pollution

Daily Science Journal (Jul. 10, 2007) — Looking at the chemical composition of stars that host planets, astronomers have found that while dwarf stars often show iron enrichment on their surface, giant stars do not. The astronomers think that the planetary debris falling onto the outer layer of the star produces a detectable effect in a dwarf star, but this pollution is diluted by the giant star and mixed into its interior.

Artist's impression of the structure of a solar-like star and a red giant. The two images are not to scale - the scale is given in the lower right corner. (Credit: Copyright ESO)

"It is a little bit like a Tiramisu or a Capuccino," says Luca Pasquini from ESO, lead-author of the paper reporting the results. "There is cocoa powder only on the top!'

Just a few years after the discovery of the first exoplanet it became evident that planets are preferentially found around stars that are enriched in iron. Planet-hosting stars are on average almost twice as rich in metals than their counterparts with no planetary system.

The immediate question is whether this richness in metals enhances planet formation, or whether it is caused by the presence of planets. The classic chicken and egg problem. In the first case, the stars would be metal-rich down to their centre. In the second case, debris from the planetary system would have polluted the star and only the external layers would be affected by this pollution.

When observing stars and taking spectra, astronomers indeed only see the outer layers and can't make sure the whole star has the same composition. When planetary debris fall onto a star, the material will stay in the outer parts, polluting it and leaving traces in the spectra taken.

A team of astronomers has decided to tackle this question by looking at a different kind of stars: red giants. These are stars that, as will the Sun in several billion years, have exhausted the hydrogen in their core. As a result, they have puffed up, becoming much larger and cooler.

Looking at the distribution of metals in fourteen planet-hosting giants, the astronomers found that their distribution was rather different from normal planet-hosting stars.

"We find that evolved stars are not enriched in metals, even when hosting planets," says Pasquini. "Thus, the anomalies found in planet-hosting stars seem to disappear when they get older and puff up!"

Looking at the various options, the astronomers conclude that the most likely explanation lies in the difference in the structure between red giants and solar-like stars: the size of the convective zone, the region where all the gas is completely mixed. In the Sun, this convective zone comprises only 2% of the star's mass. But in red giants, the convective zone is huge, encompassing 35 times more mass. The polluting material would thus be 35 times more diluted in a red giant than in a solar-like star.

"Although the interpretation of the data is not straightforward, the simplest explanation is that solar-like stars appear metal-rich because of the pollution of their atmospheres," says co-author Artie Hatzes, Director of the Thüringer Landessternwarte Tautenburg (Germany) where some of the data were obtained.

When the star was still surrounded by a proto-planetary disc, material enriched in more heavy elements would fall onto the star, thereby polluting its surface. The metal excess produced by this pollution, while visible in the thin atmospheres of solar-like stars, is completely diluted in the extended, massive atmospheres of the giants.

"Evolved stars hint to an external origin of enhanced metallicity in planet-hosting stars", by L. Pasquini et al. To appear in Astronomy and Astrophysics.

The team is composed of L. Pasquini and M.P. Döllinger (ESO), A. Weiss (Max-Planck-Institut für Astrophysik, Garching, Germany), L. Girardi (INAF-Osservatorio Astronomico di Padova, Italy), C. Chavero (Instituto de Astrofisica de Canarias, Tenerife, Spain, and Observatorio Nacional/MCT, Rio de Janeiro, Brasil), A. P. Hatzes (Thüringer Landessternwarte Tautenburg, Germany), L. da Silva (Observatorio Nacional/MCT, Rio de Janeiro, Brasil), and J. Setiawan (Max Planck Institute für Astronomie, Heidelberg, Germany).

The data have been partially collected at ESO, and partially at the 2-m telescope of the Thüringer Landessternwarte Tautenburg (TLS).

Adapted from materials provided by European Southern Observatory.

Read the rest of this entry »

Vitamin D And Flavonoids Examined For Impact On Breast And Ovarian Cancers

Daily Science Journal (Jul. 7, 2007) — While risk factors for breast and ovarian cancers include menopause, obesity, family history and specific genetic mutations, researchers also are looking at the role of diet in the development, as well as the treatment and prevention of these tumors. At the 97th Annual Meeting of the American Association for Cancer Research, two groups of scientists using sophisticated statistical techniques report their findings of possible preventive properties of Vitamin D against breast cancer. Two other groups of scientists present their work analyzing the possibility that natural antioxidants found in plants, substances called flavonoids, could play a powerful role in preventing both breast and ovarian cancer.

Potential Reduction in Breast Cancer Risk Associated with Vitamin D: Abstract No. 4009

Though scientists have suspected that Vitamin D helps to prevent and possibly even treat breast cancer, population-based studies on the possible link have been few and of limited scope.

Now, new studies by researchers at the Samuel Lunenfeld Research Institute at Mount Sinai Hospital in Toronto suggest the "sunshine" vitamin may play a significant role in reducing breast cancer risk. The results, based on population data, found the reduction was most apparent among subjects exposed to the highest levels of vitamin D when they were young.

By interviewing about 576 patients who had been diagnosed with breast cancer and 1,135 people who had no cancer, the scientists discovered that significant reductions in breast cancer were found in those who had either worked in an outdoor job, had taken part in outdoor activities when young, or consumed cod liver oil or milk.

Working an outdoor job between ages 10 to19 resulted in an estimated 40 percent reduced risk of breast cancer, while frequent outdoor activities between ages 10 to 29 lowered breast cancer risk by an estimated 35 percent.

"These outdoor activities included those that didn't involve physical activity," said Julie Knight, who headed the Mount Sinai research team. "And so we believe that this is evidence of a reduction of breast cancer risk, associated with earlier exposure to the sun."

For dietary influences on cancer development, taking cod liver oil between ages 10 to 19 reduced breast cancer risk by about 25 percent, and consuming at least nine glasses of milk every week between the ages of 10 to 29 reduced the risk by 35 percent. The dietary and lifestyle reductions were significant, even when adjusted for other risk factors for breast cancer such as age, ethnicity, close relatives with breast cancer, age at menarche and age at a woman's first birth.

"What you are exposed to during breast development may be particularly important in determining future breast cancer risk," Knight said. "Current thinking is that exposures during adolescence or before a full-term pregnancy may have a greater effect, as that is when breast tissue is going through the most rapid development."

Knight emphasizes that these findings are preliminary estimates of the risk reduction of breast cancer brought about by Vitamin D. The researchers are now looking to solidify these findings, and determine whether physical exercise while outdoors is in any way associated with breast cancer.

Evidence of Need for Increased Vitamin D Fortification of Food Based on Pooled Analysis of Studies of Serum 25-hydroxyvitamin D and Breast cancer: Abstract No. 4008

Increasing doses of dietary Vitamin D may help prevent breast cancer, with the optimal level of intake of Vitamin D more that three times the current average for Americans, according to a study conducted at the University of California, San Diego.

Previous studies have suggested a link between Vitamin D deficiency and higher incidence of breast cancer. Cedric Garland, Dr. P.H., and Edward Gorham, Ph.D., of UCSD, and their colleagues examined existing cancer studies to determine if higher Vitamin D levels in the blood could reduce the risk of cancer.

"There is a strong inverse dose-response relationship between the serum concentration of 25-hydroxyvitamin D and the risk of breast cancer," Garland said. "It's a close fit to a linear model," meaning that higher amounts of 25-hydroxyvitamin D in the serum resulted in decreased risk of breast cancer. The evidence further pointed to a level of Vitamin D measured in blood that correlated with a 50 percent reduction in the incidence of breast cancer.

Garland, Gorham and their colleagues studied a serum Vitamin D metabolite known as 25 hydroxyvitamin D and its association with breast cancer occurrence in a pooled study that included 1,760 women. The studies that provided the data for the pooled analysis were conducted by Elizabeth R. Bertone-Johnson and colleagues at Harvard, and L.C. Lowe and associates at Saint George's Hospital Medical School in London.

According to the pooled analysis, Vitamin D in blood serum equal to 52 nanograms per milliliter was associated with a 50 percent reduced risk of breast cancer. To move closer to a serum concentration of 52 nanograms/milliliter, a typical individual would have to consume no less than 1,000 International Units (IU) of Vitamin D every day, through supplements or vitamin D-fortified foods. Currently, a typical American consumes only 320 International Units of Vitamin D a day. The upper limit for vitamin D intake established by the National Academy of Sciences is 2,400 IU/day, but no toxic effects of vitamin D intake have been reported for intakes below 3,800 IU per day.

"There is no substantial downside to a serum level of 52 nanograms per milliliter of Vitamin D," said Gorham. "Such levels are common in sunny climates. There is no known adverse effect of serum levels below 160 nanograms per milliliter."

However, since many people use sunscreens and are involved in indoor occupations or shift work, dietary supplements and vitamin D fortified foods are necessary to maintain optimal levels of Vitamin D, the scientists noted.

High intakes of calcium, which could occur with intake of Vitamin D supplements containing calcium, could increase the risk of kidney stones, they warn. However, the dosage level of vitamin D associated with kidney stones in patients far exceeded 3,800 IU/day. Until more studies are completed, the scientists recommended that everyone consume at least 1,000 IU/day of vitamin D3.

Dietary Flavonoid Intake and Breast Cancer Risk among Women in the Long Island Breast Cancer Study Project: Abstract No. 4014

Flavonoids, a class of antioxidants found in plants, is associated with a reduced risk of breast cancer among post-menopausal women, according to results of the Long Island breast cancer study project. The results are one of the first epidemiologic studies to suggest that these compounds could have a chemoprotective effect among women.

Brian Fink, Susan Steck and Marilie Gammon of the University of North Carolina, Chapel Hill, and other colleagues studied data from a large study of breast cancer incidence and risk factors conducted among women living during the mid-1990s on Long Island, N.Y.

Breast cancer risk was reduced for the highest percentages of total flavonoid intake, compared to the lowest intake of the plant antioxidants. The decreased risk was about 45 percent among post-menopausal women. Risk decreases were not seen in pre-menopausal women. Specific flavonoids -- including flavones, flavan-3-ols and lignans -- were associated with reduced cancer risks ranging from 26 to 39 percent; other flavonoids, such as flavanones, isoflavones and anthocyanidins, showed no relationship with reduced cancer risk.

"These results are consistent with other studies conducted among Mediterranean women," said Fink. "Few epidemiologic studies have examined whether there is a relationship between breast cancer and dietary flavonoids. Our study proposes that dietary flavonoids can help American post-menopausal women reduce their risk of breast cancer."

The researchers examined data from the Long Island study, which was conducted by Dr. Gammon and colleagues between August 1996 and July 1997. The team compared data from 1,434 women with breast cancer to data from 1,440 women who were not diagnosed with the disease.

Flavonols, flavones, lignans and anthocyanidins are all flavonoids, molecules that give plants protection from oxidative damage due to disease and environmental stresses. Flavonoids are classified according to chemical structure, and have been studied for their varying degrees of effectiveness against human diseases, both in treatment and prevention. They are found in green tea, red wine, soybeans, fruit and vegetables.

"There are no recommended dietary standards for ingestion of flavonoids, and we do not know exactly how these chemicals may work on a cellular level," said Fink, whose work was supported with funding from the National Institutes of Health and the Lance Armstrong Foundation. "Minute differences in chemical structure could determine how a certain natural antioxidant may work to prevent disease, including cancer. More study is needed to determine why certain flavonoids appear to be effective at reducing cancer risk, and others do not appear to have these properties."

A Prospective Analysis of Dietary Flavonoid Intake and Epithelial Ovarian Cancer Incidence: Abstract No. 4013

The incidence of ovarian cancer may be reduced with increased consumption of dietary flavonoids, plant chemicals that are found in tea, red wine, fruits and vegetables, according to researchers from Brigham and Women's Hospital and the Harvard School of Public Health.

The study, conducted by Margaret Gates, a doctoral candidate at the Harvard School of Public Health, looked at food intake surveys and ovarian cancer data from 66,384 participants in the Harvard Nurses' Health Study, which collected health data from 121,700 women over a period of 30 years. "This is the first prospective analysis of flavonoid intake and ovarian cancer incidence," Gates said.

Gates studied the association between flavonoid intake from food frequency questionnaires completed by the women in 1984, 1990, 1994 and 1998; and 344 confirmed cases of ovarian cancer diagnosed between 1984 and 2002. While there was a significant trend toward decreasing incidence of ovarian cancer with increasing total flavonoid intake, Gates warned that "because this is one of the first studies of the topic, this association needs to be evaluated in another prospective study population before conclusions can be made."

Gates also analyzed individual flavonoids to evaluate their impact on ovarian cancer incidence. The flavonoid kaempferol, which the nurses consumed primarily from caffeinated tea, broccoli and kale, was associated with decreased ovarian cancer risk. Women with the highest levels of kaempferol intake had a significant 38 percent decrease in ovarian cancer incidence, compared to women with the lowest levels of intake. Two other flavonoids, myricetin and quercetin, showed a possible inverse association with ovarian cancer risk, although the results were largely non-significant.

"The associations were stronger when exposure was defined as cumulative average flavonoid intake over a period of 14 years, which suggests that long-term intake of flavonoids may be important," Gates said.

But she cautioned that "these findings need to be confirmed by others before any public health recommendations can be made. However, if confirmed, consumption of flavonoids would provide another means for women to decrease their risk of ovarian cancer."

Adapted from materials provided by American Association for Cancer Research.

Read the rest of this entry »

The Elderberry Way To Perfect Skin

Daily Science Journal (Jul. 6, 2007) — Forget expensive moisturisers and cosmetic surgery, a compound found in the humble elderberry could give a natural boost to skin.

In the first study of its kind, researchers will explore whether the skin's condition is improved by a compound which gives berries their vibrant colour (called 'anthocyanin'). (Credit: iStockphoto)

In the first study of its kind, a team of researchers led by Prof Aedin Cassidy at the University of East Anglia and Dr Paul Kroon at the Institute of Food Research, will explore whether the skin's condition is improved by a compound which gives berries their vibrant colour (called 'anthocyanin').

In a 12-week trial starting in September, post-menopausal women will consume either extracts from elderberries or placebo capsules, and will have their skin's structure and appearance measured with state-of-the-art equipment used by experts in skin science. At the same time, researchers will also test whether the elderberry extract can reduce risk factors for heart disease.

"We already know that a healthy diet can help protect against heart disease and skin damage, and that a mixture of similar food components have been shown to improve the skin's structure. There is also evidence that the active components have anti-inflammatory properties, which may be important in helping people stay healthy," said UEA's Dr Peter Curtis who is leading the project.

"If the results of our study are positive, it may lead to innovations in skin health products and may also give us vital information about diets which promote healthier hearts."

Adapted from materials provided by University of East Anglia.

Read the rest of this entry »

Difficulty Identifying Odors May Predict Cognitive Decline

Daily Science Journal (Jul. 4, 2007) — Older adults who have difficulty identifying common odors may have a greater risk of developing problems with thinking, learning and memory, according to a report in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Mild cognitive impairment--or a decline in thinking, learning and memory abilities--is increasingly recognized as a precursor to Alzheimer's disease, according to background information in the article. Impairments in the ability to recognize odors have been associated with more rapid cognitive decline and also with the development transition from mild cognitive impairment to Alzheimer's disease. However, little is known about factors that predict the development of mild cognitive impairment.

Robert S. Wilson, Ph.D., of Rush University Medical Center, Chicago, and colleagues studied 589 older adults (average age 79.9) who did not have cognitive impairment in 1997. At that time, the participants took a smell identification test, during which time 12 familiar odors were placed under their nose. They were asked to match each odor to one of four possible alternatives, and were scored from one to 12 based on the number of correct responses. At the beginning of the study and again every year for up to five years, the participants underwent a clinical evaluation that included a medical history, neurological examination and testing of their cognitive function.

During the study, 177 individuals (30.1 percent) developed mild cognitive impairment. Risk of developing mild cognitive impairment increased as odor identification decreased, so that those who scored below average (eight) on the odor identification test were 50 percent more likely to develop the condition than those who scored above average (11). This association did not change when stroke, smoking habits or other factors that might influence smell or cognitive ability were considered. Impaired odor identification was also associated with lower cognitive scores at the beginning of the study and with a more rapid decline in episodic memory (memory of past experiences), semantic memory (memory of words and symbols) and perceptual speed.

"The neurobiological bases of age-associated olfactory dysfunction are uncertain," the authors write. Evidence suggests that even before the symptoms of Alzheimer's disease develop, hallmark tangles develop in certain areas of the brain that may be associated with the processing of smells. Because difficulty identifying odors is associated with other neurological diseases, including Parkinson's disease, other mechanisms are likely involved. "Further clinicopathological and clinicoradiological research on age-related olfactory dysfunction is needed," they continue.

"Among older persons without manifest cognitive impairment, difficulty in identifying odors predicts subsequent development of mild cognitive impairment," the authors conclude. "The findings suggest that olfactory dysfunction can be an early manifestation of Alzheimer's disease ... and that olfactory assessment may be useful for early disease identification."

Adapted from materials provided by JAMA and Archives Journals, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Pioneering 3D View Of Near-Earth Magnetic 'Dance'

Daily Science Journal (Jul. 1, 2007) — Scientists have obtained the first-ever 3D picture of interconnected magnetic ‘dances’ in near-Earth space, known as magnetic reconnection events.

A diagram illustrating the null-null line observed by Cluster's four spacecraft in the Earth's magnetotail on 1 October 2001. (Credit: Inset: Chinese Academy of Sciences (C. Xiao), background: NASA)

The data from ESA’s Cluster satellites will help to understand better magnetic reconnection, a process related to star formation, solar explosions and the entry of solar wind energy into the near-Earth environment.

Magnetic reconnection is the process whereby magnetic field lines from different magnetic domains collide and reconnect, mixing previously separated plasma. Plasma is a gas composed of ions and electrons but is electrically neutral, spread over large distances in space and guided by the action of magnetic and electric fields.

Magnetic reconnection converts the energy of the magnetic field into particle energy, generating jets and heating the plasma.

This affects us here on Earth because it can possibly affect telecom satellites and prevent the efficient production of electricity in controlled fusion reactors, potential sources of electricity for the future. On Earth, we can also see the effect in more intense displays of the Northern lights.

On 1 October 2001, the four Cluster spacecraft were flying in formation at approximately 110 000 km from Earth in the magnetotail, a long-tail-like structure on the night-side of Earth’s magnetic field. The satellites meandered around a reconnection region over a period of nearly 15 minutes.

During reconnection, the geometry of the magnetic field forms an X-shape, also called a ‘magnetic null’. Analysed in 2D, the magnetic field, plasma density and flow velocity data collected during this event showed that only one reconnection region with an X-shape, or a magnetic null, was seen by the satellites.

An international team of scientists led by Chinese researchers challenged this result, suggesting that it could be seen in 3D.

The researchers tested theoretical results published 20 years ago, which predicted that any small perturbation to such a reconnection site would produce not one, but two magnetically linked reconnection sites, a pair of magnetic nulls and magnetically linked reconnection geometry.

By analysing a subset of the same data in 3D with a higher temporal resolution, they found what they were looking for. Two magnetic reconnection sites jumped out, along with the null-null line which connects two magnetic nulls, a previously unobserved phenomenon.

The situation can be compared to viewing a cross section of a 3D volume in space. It is not possible, when looking into only one plane, to tell whether or not something is going on in another plane, in the same volume of space.

Only when seen in 3D, with Cluster’s multi-satellite viewpoints, could scientists determine that there actually were two, interlinked events occurring simultaneously.

When reduced to two dimensions, this complex 3D magnetic geometry is still consistent with past results obtained under the 2D assumption where the null-null line is seen as one X-point. It is also in agreement with past results found in the laboratory and by Cluster in space.

"For the first time, the link between two sites of magnetic reconnection has been observed in-situ, in 3-D. This result is another major scientific achievement of Cluster obtained owing to fruitful scientific collaborations between Chinese, American and European scientists", said Philippe Escoubet, Cluster and Double Star project scientist of the European Space Agency.

Notes for editors:

The article “Satellite Observations of Separator Line Geometry of Three-Dimensional Magnetic Reconnection” by C. Xiao, X. Wang, Z. Pu, Z. Ma, H. Zhao, G. Zhou, J. Wang, M. Kivelson, S. Fu, Z. Liu, Q. Zong, M. Dunlop, K-H. Glassmeier, E. Lucek, H. Rème, I. Dandouras, C. Escoubet appeared on 24 June 2007 in the advance online publication of Nature Physics.

Adapted from materials provided by European Space Agency.

Read the rest of this entry »

Researchers Explain Carbon Monoxide's Anti-inflammatory Effects

Daily Science Journal (Jul. 1, 2007) — In a study appearing in the April 2007 issue of The FASEB Journal, scientists from Harvard University and the University of Pittsburgh have shown for the first time that the anti-inflammatory effects of carbon monoxide originate within cells' own molecular engines, mitochondria.

Specifically, mitochondria react to low levels of carbon monoxide by releasing chemical signals that reduce or shut down the body's inflammatory response, raising the possibility for the development of new anti-inflammatory therapies, one of which may be low levels of inhaled carbon monoxide.

According to the study's first author, Brian S. Zuckerbraun, M.D. of the University of Pittsburgh, "this study may contribute to our understanding and development of controlled carbon monoxide as a therapeutic agent."

Inflammation is a normal defense mechanism used by the body to ward off infection, but over time, severe or chronic inflammation can damage tissues. In some cases, such as in organ transplantation, the body's inflammatory response over the short-term also can cause more harm than good. Current approaches to controlling inflammation are not always successful, making the need for new approaches urgent. In particular, inhaled medical grade carbon monoxide has been shown to be useful in animal models for organ transplantation, vascular injury, inflammatory bowel disease, organ injury resulting from severe blood loss, as well as experimental hepatitis and experimental pulmonary hypertension.

"The findings described in this study are particularly relevant, given that April is National Donate Life Month," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Transplants are rejected because of inflammation gone awry. If we block inflammation, as with carbon monoxide or agents that release it in a controlled fashion, we can not only make transplantation safer, but extend its benefits to many more who need it."

Adapted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »