November 17, 2009, 7:59 AM CT
Structural brain changes in Alzheimer's disease
Serial MRI brain scans, taken six months apart, show progression from mild cognitive impairment to Alzheimer's disease, with significant atrophy (blue) and ventricle enlargement (orange/red).
Credit: University of California, San Diego, UCSD
In a study that promises to improve diagnosis and monitoring of Alzheimer's disease, researchers at the University of California, San Diego have developed a fast and accurate method for quantifying subtle, sub-regional brain volume loss using magnetic resonance imaging (MRI). The study will be published the week of November 16 in the Proceedings of the National Academy of Sciences
By applying the techniques to the newly completed dataset of the multi-institution Alzheimer's Disease Neuroimaging Initiative (ADNI), the researchers demonstrated that such sub-regional brain volume measurements outperform available measures for tracking severity of Alzheimer's disease, including widely used cognitive testing and measures of global brain-volume loss.
The general pattern of brain atrophy resulting from Alzheimer's disease has long been known through autopsy studies, but exploiting this knowledge toward accurate diagnosis and monitoring of the disease has only recently been made possible by improvements in computational algorithms that automate identification of brain structures with MRI. The new methods described in the study provide rapid identification of brain sub-regions combined with measures of change in these regions across time. The methods require at least two brain scans to be performed on the same MRI scanner over a period of several months. The new research shows that changes in the brain's memory regions, in particular a region of the temporal lobe called the entorhinal cortex, offer sensitive measures of the early stages of the disease.........
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November 17, 2009, 7:55 AM CT
Nanoparticles causes DNA damage in mice
Titanium dioxide (TiO2) nanoparticles, found in everything from cosmetics to sunscreen to paint to vitamins, caused systemic genetic damage in mice, as per a comprehensive study conducted by scientists at UCLA's Jonsson Comprehensive Cancer Center.
The TiO2 nanoparticles induced single- and double-strand DNA breaks and also caused chromosomal damage as well as inflammation, all of which increase the risk for cancer. The UCLA study is the first to show that the nanoparticles had such an effect, said Robert Schiestl, a professor of pathology, radiation oncology and environmental health sciences, a Jonsson Cancer Center scientist and the study's senior author.
Once in the system, the TiO2 nanoparticles accumulate in different organs because the body has no way to eliminate them. And because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms.
The study appears this week in the journal Cancer Research
In the past, these TiO2 nanoparticles have been considered non-toxic in that they do not incite a chemical reaction. Instead, it is surface interactions that the nanoparticles have within their environment- in this case inside a mouse - that is causing the genetic damage, Schiestl said. They wander throughout the body causing oxidative stress, which can lead to cell death.........
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November 17, 2009, 7:47 AM CT
What makes pandemic H1N1 tick?
Dr. Richard Scheuermann, professor of pathology and clinical sciences at UT Southwestern Medical Center.
As the number of deaths correlation to the pandemic H1N1 virus, usually known as "swine flu," continues to rise, scientists have been scrambling to decipher its inner workings and explain why the incidence is lower than expected in elderly adults.
In a study available online and appearing in a future issue of Proceedings of the National Academy of Sciences, a UT Southwestern Medical Center researcher and his collaborators in California show that the molecular makeup of the current H1N1 flu strain is strikingly different from prior H1N1 strains as well as the normal seasonal flu, particularly in structural parts of the virus normally recognized by the immune system.
Previous research has shown that an individual's immune system is triggered to fight off pathogens such as influenza when specific components of the immune system - namely antibodies, B-cells and T cells - recognize parts of a virus known as epitopes. An individual's ability to recognize those epitopes - spurred by past infections or vaccinations - helps prevent future infections. The challenge is that these epitopes vary among flu strains.
"We hypothesize that older people are somewhat protected because the epitopes present in flu strains before 1957 appears to be similar to those found in the current H1N1 strain, or at least similar enough that the immune system of the previously infected person recognizes the pathogen and knows to attack," said Dr. Richard Scheuermann, professor of pathology and clinical sciences at UT Southwestern and a co-author of the paper. "Those born more recently have virtually no pre-existing immunity to this pandemic H1N1 strain because they have never been exposed to anything like it".........
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November 17, 2009, 7:44 AM CT
US gets D on the March of Dimes Premature Birth Report Card
The US again earned a "D" on the second annual Premature Birth Report Card. No State earned an "A," and only Vermont earned a "B."
Credit: March of Dimes Foundation
For the second consecutive year, the United States earned only a "D" on the March of Dimes Premature Birth Report Card, demonstrating that more than half a million of our nation's newborns didn't get the healthy start they deserved.
In the 2009 Premature Birth Report card, seven states improved their performance by one letter grade and two fared worse. Criteria that affect preterm birth improved in a number of states:
- 33 states and the District of Columbia reduced the percentage of women of childbearing age who smoke;.
- 21 states and the District of Columbia reduced the percent of uninsured women of childbearing age;.
- 27 states, the District of Columbia, and Puerto Rico lowered the late preterm birth rate.
As in 2008, no state earned an "A," and only Vermont received a "B." The grades were determined by comparing preterm birth rates to the national Healthy People 2010 preterm birth objective, which is 7.6 percent of all live births. The U.S. preliminary preterm birth rate was 12.7 percent in 2007.
"Eventhough we don't yet understand all the factors that contribute to premature birth, we do know some interventions that can help prevent it, and we must consistently make use of all of these," said Dr. Jennifer L. Howse, President of the March of Dimes. She cited smoking cessation programs; health care before and during pregnancy; progesterone supplementation; and improved adherence to professional guidelines on fertility therapy and early Cesarean-sections and inductions.........
Posted by: JoAnn Read more Source
November 17, 2009, 7:36 AM CT
Those in coed college housing engage in more binge drinking
A newly released study in the Journal of American College Health finds that students placed by their universities in coed housing are 2.5 times more likely to binge drink each week than students placed in all-male or all-female housing.
More than 500 students from five college campuses around the country took part in the study:
- 42 percent of students in coed housing reported binge drinking on a weekly basis.
- 18 percent of students in gender-specific housing reported binge drinking weekly.
While that doesn't put coed housing on par with fraternity and sorority houses, the scientists note that binge drinking isn't exclusively a "Greek problem".
"In a time when college administrators and counselors pay a lot of attention to alcohol-related problems on their campuses, this is a call to more fully examine the influence of housing environment on student behavior," said Jason Carroll, a study coauthor and professor of family life at Brigham Young University. BYU was not one of the participating campuses.
Carroll's former student Brian Willoughby is the main author of the study, which will be published Nov. 17. Willoughby recently earned a Ph.D. from the University of Minnesota and returned to BYU as a visiting professor.........
Posted by: JoAnn Read more Source
November 16, 2009, 8:18 AM CT
Protein Might Prevent Cancer
Photo: Camilla Svensk
One difficulty with fighting cancer cells is that they are similar in a number of respects to the body's stem cells. By focusing on the differences, scientists at Karolinska Institutet have found a new way of tackling colon cancer. The study is presented in the prestigious journal Cell.
Molecular signal pathways that stimulate the division of stem cells are generally the same as those active in tumour growth. This limits the possibility of treating cancer as the drugs that kill cancer cells also often adversely affect the body's healthy cells, especially stem cells. A newly released study from Karolinska Institutet, conducted in collaboration with an international team of researchers led by Professor Jonas Frisen, is now focusing on an exception that can make it possible to treat a form of colon cancer.
The results concern a group of signal proteins called EphB receptors. These proteins stimulate the division of stem cells in the intestine and can contribute to the formation of adenoma (polyps), which are known to carry a risk of cancer. Paradoxically, these same proteins also prevent the adenoma from growing unchecked and becoming malignant.
The new results show that EphB controls two separate signal pathways, one of which stimulates cell division and the other that curbs the cells' ability to become malignant. Using this knowledge, the researchers have identified a drug substance called imatinib, which can inhibit the first signal pathway without affecting the other, protective, pathway.........
Posted by: Janet Read more Source
November 16, 2009, 8:12 AM CT
Just looking at your loved ones
"The very thought of you the mere idea of you".
from the song "The Very Thought of You" by Ray Noble.
Can the mere thought of your loved one reduce your pain? .
Yes, as per a newly released study by UCLA psychology experts that underscores the importance of social relationships and staying socially connected.
The study, which asked whether simply looking at a photograph of your significant other can reduce pain, involved 25 women, mostly UCLA students, who had boyfriends with whom they had been in a good relationship for more than six months.
The women received moderately painful heat stimuli to their forearms while they went through many different conditions. In one set of conditions, they viewed photographs of their boyfriend, a stranger and a chair.
"When the women were just looking at pictures of their partner, they actually reported less pain to the heat stimuli than when they were looking at pictures of an object or pictures of a stranger," said co-author of study Naomi Eisenberger, assistant professor of psychology and director of UCLA's Social and Affective Neuroscience Laboratory. "Thus, the mere reminder of one's partner through a simple photograph was capable of reducing pain." .
"This changes our notion of how social support influences people," she added. "Typically, we believe that in order for social support to make us feel good, it has to be the kind of support that is very responsive to our emotional needs. Here, however, we are seeing that just a photo of one's significant other can have the same effect." .........
Posted by: JoAnn Read more Source
November 16, 2009, 8:00 AM CT
Delivering antioxidant to injured heart cells
Fluorescent green polyketal particles stay in the heart three days after injection.
Credit: Michael Davis
Scientists at Emory University and the Georgia Institute of Technology have developed microscopic polymer beads that can deliver an antioxidant enzyme made naturally by the body into the heart.
Injecting the enzyme-containing particles into rats' hearts after a simulated heart attack reduced the number of dying cells and resulted in improved heart function days later.
Michael Davis, PhD, is presenting the results Sunday evening at the American Heart Association Scientific Sessions in Orlando. Davis is assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
The enzyme in the particles, called superoxide dismutase (SOD), soaks up toxic free radicals produced when cells are deprived of blood during a heart attack. Previously researchers have tried injecting SOD by itself into injured animals, but it doesn't seem to last long enough in the body to have any beneficial effects.
"Our goal is to have a treatment to blunt the permanent damage of a heart attack and reduce the probability of heart failure during the later part of life," Davis says. "This is a way to get extra amounts of a beneficial antioxidant protein to the cells that need it".
The simulated heart attacks caused a 20 percent decrease in the ability of the rats' hearts to pump blood that was completely prevented by the particles, he says.........
Posted by: Daniel Read more Source
November 16, 2009, 7:55 AM CT
Potential treatment for Huntington's disease
Dr. Stuart Lipton describes his Nov. 15, 2009, paper in Nature Medicine, in which he and colleagues show how synaptic activity protects the brain from the misfolded proteins that characterize Huntington's disease.
Credit: Burnham Institute for Medical Research
Investigators at Burnham Institute for Medical Research (Burnham), the University of British Columbia's Centre for Molecular Medicine and Therapeutics and the University of California, San Diego have observed that normal synaptic activity in nerve cells (the electrical activity in the brain that allows nerve cells to communicate with one another) protects the brain from the misfolded proteins linked to Huntington's disease. In contrast, excessive extrasynaptic activity (aberrant electrical activity in the brain, commonly not linked to communication between nerve cells) enhances the misfolded proteins' deadly effects. Scientists also observed that the drug Memantine, which is approved to treat Alzheimer's disease, successfully treated Huntington's disease in a mouse model by preserving normal synaptic electrical activity and suppressing excessive extrasynaptic electrical activity. The research was reported in the journal Nature Medicine
on November 15.
Huntington's disease is a hereditary condition caused by a mutated huntingtin gene that creates a misfolded, and therefore dysfunctional, protein. The new research shows that normal synaptic receptor activity makes nerve cells more resistant to the mutant proteins. However, excessive extrasynaptic activity contributed to increased nerve cell death. The research team observed that low doses of Memantine reduce extrasynaptic activity without impairing protective synaptic activity. The work was led by Stuart A. Lipton, M.D., Ph.D., director of the Del E. Webb Center for Neuroscience, Aging and Stem Cell Research at Burnham and professor in the department of Neurosciences and attending neurologist at the University of California, San Diego and Michael R. Hayden, M.D., Ph.D., University Killam professor in the department of Medical Genetics at UBC and director of the Centre for Molecular Medicine and Therapeutics at the Child & Family Research Institute.........
Posted by: Daniel Read more Source
November 16, 2009, 7:53 AM CT
Vitamin D deficiency and cardiovascular disease
While mothers have known that feeding their kids milk builds strong bones, a newly released study by scientists at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease.
For more than a year, the Intermountain Medical Center research team followed 27,686 patients who were 50 years of age or older with no previous history of cardiovascular disease. The participants had their blood Vitamin D levels tested during routine clinical care. The patients were divided into three groups based on their Vitamin D levels normal (over 30 nanograms per milliliter), low (15-30 ng/ml), or very low (less than 15 ng/ml). The patients were then followed to see if they developed some form of heart disease.
Scientists observed that patients with very low levels of Vitamin D were 77 percent more likely to die, 45 percent more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke than patients with normal levels. Patients with very low levels of Vitamin D were also twice as likely to develop heart failure than those with normal Vitamin D levels.........
Posted by: Daniel Read more Source