January 28, 2009, 6:13 AM CT

How memories change in the brain over time

A new brain imaging study illustrates what happens to memories as time goes by. The study, in the January 28 issue of The Journal of Neuroscience, shows that distinct brain structures are involved in recalling recent and older events.

The findings support earlier studies of memory-impaired patients with damage limited to the hippocampus. These patients show deficits in learning new information and in recalling events that occurred just previous to their injuries. However, they are able to recall older events, which are thought to involve other regions of the brain, especially the cortex.

"It has long been known that older memories are more resistant to hippocampal damage than newer memories, and this was thought to reflect the fact that the hippocampus becomes less involved in remembering as a memory gets older," said Russell Poldrack, PhD, an expert on the cognitive and neural mechanisms of memory at the University of California, Los Angeles, who was not involved in the study. "However, there has been a recent debate over whether the hippocampus ever really stops being involved, even for older memories," Poldrack said.

To address this debate, Christine Smith, PhD, and Larry Squire, PhD, at the University of California, San Diego and the San Diego VA Medical Center, imaged study participants as they answered 160 questions about news events that occurred over the past 30 years. The hippocampus and related brain structures were most active when recalling recent events. Hippocampal activity gradually declined as participants recalled events that were 1-12 years old and remained low when they recalled events that were 13-30 years old......... Posted by: Daniel      Read more         Source

January 28, 2009, 6:11 AM CT

Poultry disease and its risks to human health

Biodesign Institute at Arizona State University associate research scientist Melha Mellata, a member of professor Roy Curtiss' team, is leading a USDA funded project to develop a vaccine against a leading poultry disease called avian pathogenic E. coli (APEC).

APEC is part of a large, diverse group of microbes called extra-intestinal pathogenic E. coli (ExPEC). They cause many complex brain, lung and urinary tract diseases in human, animals, and birds. There is also considerable concern in the scientific community that APEC strains are becoming an emergent food pathogen. The poultry products are a suspected source of a suite of ExPEC infections, including those causing human disease.

The U.S. is the leading poultry industry in the world at an annual value of more than $50 billion, and E. coli infections are a big threat, causing millions in losses for the industry. As per the USDA, the two most common types of poultry infections are from the bacteria E. coli and Salmonella.

Antibiotics have long been the first line of defense to prevent APEC, but have lost their potency, as the bacteria have grown increasingly resistant to therapy.

How these microbes cause disease is poorly understood. Mellata and his colleagues in the institute's Center for Infectious Diseases and Vaccinology, led by Roy Curtiss, have been hard at work to understand the molecular tricks these bacteria use to evade a host's immune system......... Posted by: Janet      Read more         Source

January 28, 2009, 6:09 AM CT

Will acupuncture relieve your pain?

The pain relieving effects of acupuncture compared with placebo are small and seem to lack clinical relevance, as per a research studypublished on bmj.com today.

Scientists at the Nordic Cochrane Centre in Copenhagen analysed evidence from thirteen acupuncture pain trials involving over 3,000 patients. The trials compared three arms of therapy (real acupuncture, placebo or 'pretend' acupuncture or no acupuncture) for a broad range of common conditions such as knee osteoarthritis, migraine, low back pain and post-operative pain.

Before the analysis, differences in study design and quality were taken into account to minimise bias.

They found a small analgesic effect of real acupuncture in comparison to placebo acupuncture. This corresponded to a reduction in pain levels of about 4mm on a 100mm pain scoring scale. A 10mm reduction on this scale is classed as 'minimal' or 'little change' so the apparent analgesic effect of acupuncture seems to be below a clinically relevant pain improvement, say the authors.

They found a moderate difference between placebo acupuncture and no acupuncture (10mm on a 100mm pain scoring scale), but the effect of placebo acupuncture varied considerably. Some large trials reported effects of placebo that were of clear clinical relevance (24mm), whereas other large trials found effects that seemed clinically irrelevant (5mm)......... Posted by: Janet      Read more         Source

January 28, 2009, 6:06 AM CT

Neural mechanisms of empathy

Is it possible to share a pain that you observe in another but have never actually experienced yourself? A newly released study uses a sophisticated brain-imaging technique to try and answer this question. The research, published by Cell Press in the January 29th issue of the journal Neuron, provides insight into brain mechanisms involved in empathy.

Brain-imaging studies have shown similar patterns of brain activity when subjects feel their own emotions or observe the same emotions in others. It has been suggested that a person who has never experienced a specific feeling would have a difficult time directly empathizing with a person through a "mirror matching" mechanism that requires prior experience and would instead have to rely on a higher inferential processes called "perspective taking."

"Patients with congenital insensitivity to pain (CIP) offer a unique opportunity to test this model of empathy by exploring how the lack of self-pain representation might influence the perception of others' pain," explains main author Dr. Nicolas Danziger from the Department of Clinical Neurophysiology and Pain Center at the Pitie-Salpetriere in Paris, France.

Dr. Danziger and his colleagues had previously shown that CIP patients underestimated the pain of others when emotional cues were lacking and, in contrast with control subjects, the ability to fully acknowledge others' pain depended on a capacity for empathy. In this study, the scientists used functional magnetic resonance imaging (fMRI) to compare brain activation patterns in CIP patients and controls who were asked to imagine the feelings of a person in a photo that showed body parts in painful situations or facial expressions of pain......... Posted by: Daniel      Read more         Source

January 27, 2009, 6:25 AM CT

Differences in thinking styles

Consumers approach problems, products, and websites differently as per distinct thinking styles, says a newly released study in the Journal of Consumer Research

Authors Thomas P. Novak and Donna L. Hoffman (both University of California, Riverside) say consumers tend to think either rationally or experientially and marketers should design experiences for consumers that allow a good fit between the style and the task.

The authors describe rational thinking as "logical, effortful, and analytic," and experiential thinking as "associative, lower effort, and holistic." Examples of rational activities include work, carefully considered decisions, and goal-directed tasks, while experiential activities include playing, browsing, and impulse buying.

The authors developed a measure called the Situation-Specific-Thinking-Style measure (SSTS), which measured and predicted study participants' performance on many tasks, including vocabulary and geometry problems (rational) or activities such as suggesting ways to improve toys or websites (experiential).

"We observed that people who reported thinking rationally performed better on rational tasks, and people who reported thinking experientially performed better on experiential tasks," explain the authors. "In addition, the 'wrong type' of thinking actually hurt performance. People who approached a vocabulary or an IQ test problem in an experiential, intuitive manner actually had fewer correct answers than those who approached the problem logically."........ Posted by: JoAnn      Read more         Source

January 27, 2009, 6:24 AM CT

Huge burden of diabetes

In the United States, nearly 13 percent of adults age 20 and older have diabetes, but 40 percent of them have not been diagnosed, as per epidemiologists from the National Institutes of Health (NIH) and the Centers for Disease Control and Prevention (CDC), whose study includes newly available data from an Oral Glucose Tolerance Test (OGTT). Diabetes is particularly common in the elderly: nearly one-third of those age 65 and older have the disease. An additional 30 percent of adults have pre-diabetes, a condition marked by elevated blood sugar that is still not in the diabetic range. The scientists report these findings in the February 2009 issue of Diabetes Care, which posted a pre-print version of the article online at http://diabetes.org/diabetescare.

The study compared the results of two national surveys that included a fasting blood glucose (FBG) test and 2-hour glucose reading from an OGTT. The OGTT gives more information about blood glucose abnormalities than the FBG test, which measures blood glucose after an overnight fast. The FBG test is easier and less costly than the OGTT, but the 2-hour test is more sensitive in identifying diabetes and pre-diabetes, particularly in older people. Two-hour glucose readings that are high but still not diabetic indicate a greater risk of cardiovascular disease and of developing diabetes than a high, but still not diabetic, fasting glucose level......... Posted by: JoAnn      Read more         Source

January 27, 2009, 6:18 AM CT

Fast-food diet cancels out benefits of breastfeeding

A number of studies have shown that breastfeeding appears to reduce the chance of children developing asthma. But a newly published study led by a University of Alberta professor has observed that eating fast food more than once or twice a week negated the beneficial effects that breastfeeding has in protecting children from the respiratory disease.

The article appears online in the international journal Clinical and Experimental Allergy based in London, England. Many different findings led the scientists to their conclusion showing links between fast food and asthma, breastfeeding and asthma, and all three together.

"Like other studies, we observed that fast-food consumption was linked to asthma," said the senior author, Dr. Anita Kozyrskyj (pronounced koh-ZUHR-skee), an associate professor in the Department of Pediatrics in the U of A's Faculty of Medicine & Dentistry.

The research confirmed the findings of a number of other studies about the benefits of breastfeeding in relation to asthma. Kozyrskyj et al. observed that breastfeeding for too short a time was associated with a higher risk of asthma, or on the other hand that children exclusively breastfed 12 weeks or longer as infants had a lower risk.

"But this beneficial effect was only seen in children who did not consume fast food, or only occasionally had fast food," she added......... Posted by: JoAnn      Read more         Source

January 26, 2009, 11:40 PM CT

'Happiness gap' in the US narrows

Happiness inequality in the U.S. has decreased since the 1970s, as per research published this month in the Journal of Legal Studies

The study, by University of Pennsylvania economists Betsey Stevenson and Justin Wolfers, observed that the American population as a whole is no happier than it was three decades ago. But happiness inequalitythe gap between the happy and the not-so-happyhas narrowed significantly.

"Americans are becoming more similar to each other in terms of reported happiness," says Stevenson. "It's an interesting finding because other research shows increasing gaps in income, consumption and leisure time".

The happiness gap between whites and non-whites has narrowed by two-thirds, the study found. Non-whites report being significantly happier than they were in the early part of 1970s, while whites are slightly less happy. The happiness gap between men and women closed as well. Women have become less happy, while men are a little more cheerful.

One demographic area where the happiness gap increased was in educational attainment. People with a college diploma have gotten happier, while those with a high school education or less report lower happiness levels.

Stevenson and Wolfers used data collected from 1972 to 2006 through the University of Chicago's General Social Survey. Each year, participants were asked, "Taken all together, how would you say things are these dayswould you say that you are very happy, pretty happy, or not too happy?"......... Posted by: JoAnn      Read more         Source

January 26, 2009, 11:37 PM CT

Statins may treat blood vessel disorder

In a finding that could save thousands of lives a year, University of Utah School of Medicine scientists have shown that a blood vessel disorder leading to unpredictable, sometimes fatal, hemorrhagic strokes, seizures, paralysis or other problems is treatable with the same statin drugs that millions of people take to control high cholesterol.

If the results of a study in mice are confirmed in a pilot trial with people, statins could provide a safe, inexpensive therapy for cerebral cavernous malformation (CCM), a disorder with no known drug treatment, as per U of U heart specialist Dean Y. Li, M.D., Ph.D., director of the Molecular Medicine Program and corresponding author of a study published Jan. 18 in Nature Medicine online.

"Brain surgery or radiation therapy has been the only option for CCM patients. But because of the risks in those operations, neurosurgeons are reluctant to perform them unless the patient is in immediate danger," Li said. "Our study proposes a potential strategy for a simple drug treatment that could cost only a few dollars a month at a pharmacy. However, our animal studies must first be reviewed in a pilot clinical trial being initiated".

Kevin J. Whitehead, M.D., also a heart specialist, assistant professor of internal medicine, and first author of the study, now is recruiting 50 to 100 people diagnosed with CCM to join a pilot trial of statins......... Posted by: Daniel      Read more         Source

January 26, 2009, 11:35 PM CT

Controversy of using stimulants to treat asthma

HOUSTON Just when the Food and Drug Administration is reconsidering the use of stimulants to treat asthma, a new research study offers further evidence to support a University of Houston professor's theory that an opposite approach to asthma treatment may be in order.

Richard A. Bond, professor of pharmacology at the University of Houston College of Pharmacy (UHCOP), has been investigating whether beta-2 adrenoreceptor antagonist drugs (or beta blockers) ultimately might be a safer, more effective strategy for long-term asthma management than the currently used beta-2 adrenoreceptor agonists (or stimulants).

The beta-2 adrenoreceptor is a receptor found in many cells, including the smooth muscle lining the airways, and has long been a target for asthma drugs. However, a recent study shows the absence of asthma-like symptoms in a mouse model that lacks the key gene that produces the receptor. This lends further evidence to Bond's theory that questions whether the pharmaceutical industry should be working to block or inhibit the receptor instead of the current approach of chronically stimulating it to reduce asthma symptoms.

The study, "Beta2-Adrenoreceptor Signaling is Required for the Development of an Asthma Phenotype in a Murine Model," is in the current online issue of the journal Proceedings of the National Academy of Sciences (PNAS), one of the world's most-cited multidisciplinary scientific serials. A follow-up commentary by an independent scientist in the field also would be published in the print issue of PNAS in February......... Posted by: JoAnn      Read more         Source