August 21, 2009, 7:16 AM CT

Why sleep?

Bats, birds, box turtles, humans and a number of other animals share at least one thing in common: They sleep. Humans, in fact, spend roughly one-third of their lives asleep, but sleep scientists still don't know why.

As per the journal Science, the function of sleep is one of the 125 greatest unsolved mysteries in science. Theories range from brain "maintenance" including memory consolidation and pruning to reversing damage from oxidative stress suffered while awake, to promoting longevity. None of these theories are well established, and a number of are mutually exclusive.

Now, a new analysis by Jerome Siegel, UCLA professor of psychiatry and director of the Center for Sleep Research at the Semel Institute for Neuroscience and Human Behavior at UCLA and the Sepulveda Veterans Affairs Medical Center, has concluded that sleep's primary function is to increase animals' efficiency and minimize their risk by regulating the duration and timing of their behavior.

The research appears in the current online edition of the journal Nature Reviews Neuroscience

"Sleep has normally been viewed as something negative for survival because sleeping animals appears to be vulnerable to predation and they can't perform the behaviors that ensure survival," Siegel said. These behaviors include eating, procreating, caring for family members, monitoring the environment for danger and scouting for prey......... Posted by: Daniel      Read more         Source

August 21, 2009, 7:14 AM CT

Visits Nana's with your toddlers

It's easy to list the negative stereotypes attributed to the elderly: they are considered forgetful, hard-of-hearing, absent-minded and confused.

What's unsettling is that those stereotypes can be present in children as young as two or three.

Research conducted by the University of Alberta's Sheree Kwong See, a psychology researcher, has identified that those stereotypes exist in some children at that age, which could adversely affect them when they are older.

"We've been able to show really early on that kids, when they're just starting to talk, have established beliefs about older people," said Kwong See. "We're seeing what we could call ageism by about age three".

In a recent study to be reported in the journal Educational Gerontology, Kwong See and fellow researcher Elena Nicoladis measured the reactions of young children after being quizzed on vocabulary words by either an older or younger adult. Results showed that children who had less exposure to elderly adults had a stronger language bias against the older person in the experiment than those who had more exposure to older people.

"If you are interacting with 'nana' more frequently, you'll start to see that she's a pretty good teacher of words even though she's old," said Kwong See. "When you have little contact dominant negative cultural stereotypes emerge. You think an older person isn't as alert or in-the-know as a young person and maybe is not as good a teacher"......... Posted by: JoAnn      Read more         Source

August 21, 2009, 7:11 AM CT

Universal Influenza Vaccination

We all know that influenza vaccination helps prevent disease, but a newly released study from Canada suggests it may also prevent another public health problem: inappropriate antibiotic use. The findings come from a newly released study in the September 1, 2009 issue of Clinical Infectious Disease, which is now available online.

Starting in 2000, the Canadian province of Ontario introduced a universal immunization program offering free influenza vaccines to anyone 6 months of age or older. Other provinces continued to target only high-risk groups and their contacts for vaccination. The authors compared prescription rates for influenza-associated respiratory antibiotics before and after the Ontario program began, and compared the Ontario prescription rates with those of other provinces.

The broader immunization effort in Ontario was linked to a 64 percent decline in these antibiotic prescriptions compared with the other provinces that maintained targeted vaccination programs. Additionally, influenza-associated mortality fell 39 percent. Flu-related hospitalizations, emergency department use, and doctors' office visits also fell an average of 52 percent.

Influenza and upper respiratory conditions account for a substantial number of antibiotic prescriptions, even though antibiotics don't work against viruses such as the flu. The overuse of antibiotics and the development of antibiotic-resistant bacteria continue to be serious public health problems. As per study author Fawziah Marra, PharmD, of the University of British Columbia, the study's findings suggest that "jurisdictions wishing to decrease antibiotic use might consider programs to increase influenza vaccination"......... Posted by: Mark      Read more         Source

August 21, 2009, 7:10 AM CT

Alcohol advertising reaching too many teens on cable

A newly released study from the Center on Alcohol Marketing and Youth, in collaboration with UCLA, has found a striking connection between teenage viewership and the frequency of alcohol advertising on cable television. The findings show that ads for beer, spirits and "alcopop" aired much more frequently when more teens were watching.

While prior studies have shown that the average adolescent is exposed to well over 200 alcohol ads on television each year, this is the first to demonstrate an association between ad placement and teen cable TV viewership. Cable TV attracts about 95 percent of all nationally televised alcohol ads.

The study would be reported in the recent issue of the American Journal of Public Health and is currently available online by subscription.

"Alcohol advertisers have pledged to avoid audiences made up of more than 30 percent underage viewers such as children's programming," said David H. Jernigan, director of the Center on Alcohol Marketing and Youth and an associate professor at the Johns Hopkins Bloomberg School of Public Health. "However, a number of other shows have adolescent appeal. This research suggests that ads are aimed at groups that include a disproportionate number of teens and that the alcohol industry's voluntary self-monitoring is not working to reduce adolescent exposure to ads."........ Posted by: Janet      Read more         Source

August 21, 2009, 7:08 AM CT

Evolution of the appendix

The lowly appendix, long-regarded as a useless evolutionary artifact, won newfound respect two years ago when scientists at Duke University Medical Center proposed that it actually serves a critical function. The appendix, they said, is a safe haven where good bacteria could hang out until they were needed to repopulate the gut after a nasty case of diarrhea, for example.

Now, some of those same scientists are back, reporting on the first-ever study of the appendix through the ages. Writing in the Journal of Evolutionary Biology, Duke researchers and collaborators from the University of Arizona and Arizona State University conclude that Charles Darwin was wrong: The appendix is a whole lot more than an evolutionary remnant. Not only does it appear in nature much more frequently than previously acknowledged, but it has been around much longer than anyone had suspected.

"Maybe it's time to correct the textbooks," says William Parker, Ph.D., assistant professor of surgical sciences at Duke and the senior author of the study. "A number of biology texts today still refer to the appendix as a 'vestigial organ.'".

Using a modern approach to evolutionary biology called cladistics, which utilizes genetic information in combination with a variety of other data to evaluate biological relationships that emerge over the ages, Parker and his colleagues observed that the appendix has evolved at least twice, once among Australian marsupials and another time among rats, lemmings and other rodents, selected primates and humans. "We also figure that the appendix has been around for at least 80 million years, much longer than we would estimate if Darwin's ideas about the appendix were correct"......... Posted by: Janet      Read more         Source

August 21, 2009, 7:05 AM CT

Off-label use: Oft not evidence based

In a recent national survey, a substantial minority of physicians erroneously believed that certain off-label uses of prescription drugs were approved by the Food and Drug Administration. This mistaken belief could encourage them to prescribe these drugs, despite the lack of scientific evidence supporting such use.

"Off-label prescribing is common, but scientists have not always known why. Our research shows that some off-label prescribing might be driven by mistaken beliefs about FDA approval and the level of evidence supporting off-label drug use," said G. Caleb Alexander, MD, MS, Assistant Professor of Medicine at the University of Chicago Medical Center and corresponding author of the research, which will be published under an embargo in Pharmacoepidemiology and Drug Safety on August 21, 2009. "The results indicate an urgent need for more effective methods of informing physicians about the level of evidence supporting off-label drug useparticularly for common off-label uses that are ineffective or carry unacceptable risks of harm".

Overall, physicians were able to correctly identify the FDA-approval status of just over half (mean 55%) of the 22 drug-indication pairs (i.e., a particular drug prescribed for a particular condition) that were included in the survey......... Posted by: Janet      Read more         Source

August 20, 2009, 7:04 AM CT

New targets for treatment of invasive breast cancer

Research led by Suresh Alahari, PhD, Associate Professor of Biochemistry and Molecular Biology at LSU Health Sciences Center New Orleans, has demonstrated for the first time that a tiny piece of RNA appears to play a major role in the development of invasive breast cancer and identified a gene that appears to inhibit invasive breast cancer. The research is reported in the August 21, 2009 issue of the Journal of Biological Chemistry

The LSUHSC scientists are the first to demonstrate that miR-27b, a novel microRNA, not only inactivates the ST14 gene which they found suppresses the growth of breast tumor cells, but also that miR-27b stimulates the breast cancer to invade other cells.

MicroRNAs are a new class of small, single-stranded RNA molecules which play an important regulatory role in cell biology. They bind to target genes and decrease their function. MicroRNAs may act as oncogenes (a gene that contributes to cancer development) or tumor suppressors.

In this study working with a line of human breast cancer cells, Dr. Alahari's team observed that aggressively invasive breast tumor cells contain a large quantity f miR-27b molecules, while normal cells do not. Further analysis revealed that miR-27b increases during cancer progression, in direct proportion to the decrease in function of the ST14 gene. They observed that miR-27b promotes cell growth and cell invasion, suggesting that miR-27b acts as a breast cancer oncogene. They also observed that ST14 inhibits both cell growth and cell invasion, suggesting that ST14 is a breast cancer tumor suppressor gene and that it may also serve as a marker for the early detection of breast cancer......... Posted by: Janet      Read more         Source

August 20, 2009, 7:03 AM CT

Stem Cells Repair the Human Brain

There is no known cure for neurodegenerative diseases such as Huntington's, Alzheimer's and Parkinson's. But new hope, in the form of stem cells created from the patient's own bone marrow, can be found - and literally seen - in laboratories at Tel Aviv University.

Dr. Yoram Cohen of TAU's School of Chemistry has recently proven the viability of these innovative stem cells, called mesenchymal stem cells, using in-vivo MRI. Dr. Cohen has been able to track their progress within the brain, and initial studies indicate they can identify unhealthy or damaged tissues, migrate to them, and potentially repair or halt cell degeneration. His findings have been published in the journal Stem Cells.

"By monitoring the motion of these cells, you get information about how viable they are, and how they can benefit the tissue," he explains. "We have been able to prove that these stem cells travel within the brain, and only travel where they are needed. They read the chemical signalling of the tissue, which indicate areas of stress. And then they go and try to repair the situation".

Tracking live cells in the brain

To test the capabilities of this innovative new stem cells, Dr. Cohen created a study to track the activity of the live cells within the brain using the in-vivo MRI at the Strauss Centre for Computational Neuro-Imaging. Watching the live, active cells has been central to establishing their viability as a treatment for neurodegenerative disease......... Posted by: Scott      Read more         Source

August 20, 2009, 6:48 AM CT

Living longer and happier

A newly released study from the University of Missouri may shed light on how to increase the level and quality of activity in the elderly. In the study, published in this week's edition of Public Library of Science ONE, MU scientists observed that gene treatment with a proven "longevity" gene energized mice during exercise, and might be applicable to humans in the future.

"Aging is one of the biggest challenges to a modern society. A pressing issue in the elderly is the loss of activity. What one really wants is not a simple lifespan prolongation but rather a health span increase," said Dongsheng Duan, an associate professor of molecular microbiology and immunology. "After gene treatment with a 'longevity' gene, we studied how well the mice performed on treadmill exercises. We observed that the gene treatment worked well and the mice functioned better after the therapy".

Earlier studies have observed that mice would live longer when their genome was altered to carry a gene known as mitochondria-targeted catalase gene, or MCAT. However, such approaches would not be applicable to human. Duan and Dejia Li, a post-doctoral researcher working with Duan, took a different approach and placed the MCAT gene inside a non-malignant virus and injected the virus into the mice......... Posted by: Janet      Read more         Source

August 20, 2009, 6:45 AM CT

Anti-Aging Gene Linked to High Blood Pressure

Scientists at the University of Oklahoma Health Sciences Center have shown the first link between a newly discovered anti-aging gene and high blood pressure. The results, which appear this month in the journal Hypertension, offer new clues on how we age and how we might live longer.

Persistent hypertension, or high blood pressure, is a risk factor for stroke, heart attack, heart failure, arterial aneurysm and is the leading cause of chronic kidney failure. Even a modest elevation of arterial blood pressure leads to shortened life expectancy.

Researchers, led by principal investigator Zhongjie Sun, tested the effect of an anti-aging gene called klotho on reducing hypertension. They observed that by increasing the expression of the gene in laboratory models, they not only stopped blood pressure from continuing to rise, but succeeded in lowering it. Perhaps most impressive was the complete reversal of kidney damage, which is linked to prolonged hypertension and often leads to kidney failure.

"One single injection of the klotho gene can reduce high blood pressure for at least 12 weeks and possibly longer. Klotho is also available as a protein and, conceivably, we could ingest it as a powder much like we do with protein drinks," said Sun, M.D., Ph.D., a cardiovascular expert at the OU College of Medicine......... Posted by: Janet      Read more         Source