October 1, 2007, 8:57 PM CT
Light on human aging
Microscopic worms used for scientific research are living longer despite cellular defects, a discovery that is shedding light on how the human body ages and how doctors could one day limit or reverse genetic mutations that cause inherited diseases, as per a new University of Colorado at Boulder study.
In the first formal study of its kind, scientists manipulated the metabolic state of genetically engineered lab worms called C. elegans and discovered a window of high-efficiency cellular processing that enabled the worms to slow their rate of aging. The findings could one day contribute to the creation of gene therapies to reverse or lessen the effects of mitochondrial diseases, the largest family of human genetic diseases, said lead study author Shane Rea of CU-Boulder's Institute for Behavioral Genetics.
Diseases labeled as mitochondrial are those that affect the mitochondria, the membrane-enclosed power sources present in all cells, Rea said. Scientists believe their insights might find application in treating diseases associated with mitochondrial dysfunction such as Huntington's, Parkinson's and Alzheimer's.
"We appear to have found a window where life is able to preserve itself even better than when operating in the absence of any cellular defects," said Rea. "It's a metabolic state where cells are probably getting close to the best they can be for long life and good health".........
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September 25, 2007, 5:04 AM CT
Eye Movement Can Affect Problem-solving
A pair of Beckman Institute scientists has discovered that by directing the eye movements of test subjects they were able to affect the participants' ability to solve a problem, demonstrating that eye movement is not just a function of cognition but can actually affect our cognitive processes.
Prior research (Grant and Spivey, 2003) has shown a relationship between eye movements and problem-solving but Psychology Professor Alejandro Lleras, a member of the Human Perception and Performance group, and Ph.D. candidate Laura Thomas have taken that work in a groundbreaking direction.
They report in the current (Aug., 2007) issue of Psychonomic Bulletin and Review that by occasionally guiding the eye movements of participants with a tracking task uncorrelation to the problem, they were able to "substantially affect their chances of problem-solving success" to the point where those groups outperformed every control group at solving the problem. These results, they conclude, demonstrate that "it is now clear that not only do eye movements reflect what we are thinking, they can also influence how we think".
The prior work of Grant and Spivey suggested a relationship between eye movements and problem-solving by showing that certain patterns of eye movement were reflected as participants got closer to solving the problem.........
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September 24, 2007, 9:58 PM CT
New treatment for shoulder pain
Inflammation of a tendon triggered by calcium deposits, or calcific tendinitis, can effectively be treated with a simple and cost effective percutaneous method as per a recent study conducted by scientists from the Hospital de Basurto in Bilbao, Spain.
We started treating calcific tendinitis as the result of the request of several members of our hospital staff that were suffering with this condition, said Jose Luis del Cura, MD, lead author of the study. The results we obtained in these few cases encouraged us to offer this therapy to our patients. Later, in collaboration with the rheumatology department of our hospital, we conducted a study to evaluate the efficacy of the procedure, said Dr. del Cura.
The study consisted of 67 shoulders that were treated with sonographically guided percutaneous needle lavage i.e. injections of lydocaine or saline. As per the study, one year after therapy, 91% of shoulders had considerably or completely improved. Of the 67 shoulders treated, 64% had perfect motion and the calcifications had resolved completely or nearly completely in 89% of the patients.
A significant amount of the patients (about half of them) experienced a transitory limited recurrence about two months after the therapy, which we found surprising, said Dr. del Cura. When the recurrence did occur, the symptoms were different; milder and predominately at night, lasted several weeks and finally disappeared, commonly without sequels. We hypothesized that this may have been the result of reparative changes inside the tendon, he said.........
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September 23, 2007, 12:09 AM CT
Is there really a 'mommy' gene in women?
Basic principles of biology rather than women's newfound economic independence can explain why fewer of them are getting married and having children, and why the trend may only be temporary, says a Queen's researcher.
"Only in recent times have women acquired significant control over their own fertility, and a number of are preferring not to be saddled with the burden of raising children," says Lonnie Aarssen, a Biology professor who specializes in reproductive ecology. "The question is whether this is just a result of economic factors and socio-cultural conditioning, as most analysts claim, or whether the choices that women are making about parenthood are influenced by genetic inheritance from maternal ancestors that were dominated by paternal ancestors." .
In a paper reported in the current issue of Oikos - an international journal of ecology - Dr. Aarssen suggests that because of inherited inclinations, a number of women when empowered by financial independence are driven to pursue leisure and other personal goals that distract from parenthood.
"The drive to leave a legacy through offspring can be side-tracked by an attraction to legacy through other things like career, fame, and fortune - distractions that, until recently, were only widely available to men".........
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September 23, 2007, 11:01 AM CT
Genetic risk for fetal alcohol disorders
New research in primates suggests that infants and children who carry a certain gene variant may be more vulnerable to the ill effects of fetal alcohol exposure.
Reported online today (Sept. Typically 21) in biological psychiatry, the findings represent the first evidence of a genetic risk for fetal alcohol spectrum disorder - a condition that is characterized by profound mental retardation in its most severe form, but which is also linked to deficits in learning, attention, memory and impulse control.
By identifying a genetic marker that might signal susceptibility to these more subtle fetal alcohol-induced problems, the research fills a pressing need, says Mary Schneider, the University of Wisconsin-Madison professor of kinesiology and psychology who led the study.
"The big concern used to be the link between fetal alcohol exposure and mental retardation, but today there is increased concern over behavioral problems in these children," says Schneider. "If this genetic marker could provide a way of recognizing the most vulnerable fetal alcohol-exposed children early in life, perhaps we could help them to live more successful and satisfying lives".
The study's results may also help to explain why some children of mothers who drink during pregnancy suffer birth defects, while others seem to escape unharmed.........
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September 23, 2007, 10:57 AM CT
Hundreds of genes controlling female fertility
Scientists at UT Southwestern Medical Center have found nearly 350 genes correlation to female fertility. Their research may open the door to much wider study in the poorly understood field of infertility.
This study gives us a way to begin to understand the causes of female infertility, said Dr. Diego Castrillon, assistant professor of pathology and senior author of a study appearing in the recent issue of the journal Genetics
It gives us a much more complete list of candidate genes to explore. Before, we didnt even know where to look.
The study was done in mice, but at the molecular level, ovarian biology is very similar in mice and humans, Dr. Castrillon said.
These discoveries might lead the way to eventually allowing clinicians to test whether an infertile woman has problems with a specific gene, allowing for improved diagnostic tests and tailored treatment in the future, said Dr. Castrillon, a specialist in the diagnosis of infertility and other diseases of women.
About 13 percent of women suffer from infertility, with the most common cause being dysfunction of the ovary. Scientists suspected genetic links in a number of cases, Dr. Castrillon said.
In mammals, the ovaries go through a developmental stage after birth in which egg cells become nestled in dormant nests called primordial follicles. Later in development, the follicles become activated by a process that scientists dont fully understand, and at puberty, egg cells begin being released for fertilization.........
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September 23, 2007, 10:55 AM CT
Vitamin E trials 'fatally flawed'
Generations of studies on vitamin E may be largely meaningless, researchers say, because new research has demonstrated that the levels of this micronutrient necessary to reduce oxidative stress are far higher than those that have been usually used in clinical trials.
In a new study and commentary in Free Radical Biology and Medicine, scientists concluded that the levels of vitamin E necessary to reduce oxidative stress as measured by accepted biomarkers of lipid peroxidation are about 1,600 to 3,200 I.U. daily, or four to eight times higher than those used in almost all past clinical trials.
This could help explain the inconsistent results of a number of vitamin E trials for its value in preventing or treating cardiovascular disease, said Balz Frei, professor and director of the Linus Pauling Institute at Oregon State University, and co-author of the new commentary along with Jeffrey Blumberg, at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.
The methodology used in almost all past clinical trials of vitamin E has been fatally flawed, said Frei, one of the worlds leading experts on antioxidants and disease. These trials supposedly addressed the hypothesis that reducing oxidative stress could reduce cardiovascular disease. But oxidative stress was never measured in these trials, and therefore we dont know whether it was actually reduced or not. The hypothesis was never really tested.........
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September 18, 2007, 8:05 PM CT
Eat Smart. Play Hard
Christina Economos, PhD, principal investigator of Shape Up Somerville: Eat Smart. Play Hard, a large-scale community intervention to curb childhood obesity, will present her research at the second annual Friedman School Symposium at Tufts, October 29th to 31st in Boston.
Shape Up Somerville was a 3 year long obesity prevention intervention targeted at first through third graders in the culturally diverse Boston suburb of Somerville, Massachusetts.
Eager to turn the tide on childhood obesity, the town leaders of Somerville, community partners, and university scientists joined forces to spark community change and build an innovative, health-minded environment for the children. The Shape Up approach emphasized manageable and affordable changes in behavior and nutrition throughout the course of the day. Whats more, it worked. The intervention decreased BMI z score in children at high-risk for obesity, in comparison to the two control communities.
"There are lots of communities around the country attempting to make changes and what this study tells us is they should persevere," Economos said.
"A lot of people making a few small changes added up to produce significant results," says Dr. Economos. "We couldn't go to the kids and say you have to change your lifestyle. We had to change the environment and the community spirit first".........
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September 17, 2007, 5:10 AM CT
Linchpin gene and breast cancer therapies
University of Iowa scientists have discovered a gene that plays a linchpin role in the ability of breast cancer cells to respond to estrogen. The finding may lead to improved therapies for hormone-responsive breast cancers and may explain differences in the effectiveness of current therapys.
Estrogen causes hormone-responsive breast cancer cells to grow and divide by interacting with estrogen receptors made by cancer cells. Interfering with estrogen signaling is the basis of two common breast cancer therapies -- tamoxifen, which blocks estrogen's interaction with a primary estrogen receptor called ER-alpha, and aromatase inhibitors that reduce the amount of estrogen the body makes and therefore affect any pathway that uses estrogen.
The study, led by Ronald Weigel, M.D., Ph.D., professor and head of surgery at the University of Iowa Roy J. and Lucille A. Carver College of Medicine, reveals a central role for transcription factor AP2C (TFAP2C) in controlling multiple pathways of estrogen signaling. The findings appear in the Sept. 15 issue of Cancer Research.
"Estrogen binds to estrogen receptors and triggers a cascade of events including gene regulation," said Weigel, who also is a member of the Holden Comprehensive Cancer Center at the UI. "We observed that elimination of the TFAP2C from the cell causes all of those cascades that we associate with estrogen to go away. The treated cancer cells were not able to respond to estrogen by any normal pathway".........
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September 17, 2007, 5:02 AM CT
Genetic variant linked to odor perception
Why the same sweaty man smells pleasant to one person and repellant to another comes down to the smellers genes.
Duke University Medical Center scientists demonstrated that genetic variants of odor receptors within the nose determine how a particular odor is perceived. The researchers, led by Dukes Hiroaki Matsunami, Ph.D., assistant professor of molecular genetics and microbiology, published the results of their experiments early online Sept. 16 in the journal Nature.
The scientists focused on two chemicals androstenone and androstadienone that are created naturally by the body during the breakdown of the male sex hormone testosterone and are excreted in sweat and urine.
We observed that genetic variations of a specific odor receptor determine, to a significant degree, why the same chemicals smell pleasant or unpleasant to different people, Matsunami said. These results demonstrate the first link between the functioning of a human odor receptor gene and how that odor is perceived.
Humans have about 400 odor receptors within the nose that detect various odors or chemicals. Smells typically bind to their corresponding receptors, and the information is then relayed to the brain for processing.
The scientists wanted to uncover the reasons why people react differently when they smell these two sex steroid-derived chemicals. Hanyi Zhuang, a student in the Matsunami laboratory, tested all the known smell receptors in the laboratory and found one that reacted strongly with the two chemicals.........
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