Category: Health & Medicine

Breathing technique can reduce frequency, severity of asthma attacks

Post author By Margaret Allen
Post date August 14, 2009

Mueret10%2C-9-09%2Clr.jpg As the health care reform debate turns to cutting costs and improving treatment outcomes, two SMU professors are expanding a study that shows promise for reducing both the expense and suffering associated with chronic asthma.

Thomas Ritz and Alicia Meuret, both of SMU’s Psychology Department, have developed a four-week program to teach asthmatics how to better control their condition by changing the way they breathe.

With the help of a four-year, $1.4 million grant from the National Institutes of Health, they plan to engage 120 Dallas County patients in four weeks of breathing training by the study’s projected end in July 2012. Their co-investigators include David Rosenfield, also of SMU’s Psychology Department, and Mark Millard, M.D., of Baylor University Medical Center.

Mueret8%2C-9-09%2Clr.jpg More than 22 million Americans suffer from asthma at an estimated annual economic cost of more than $19 billion, according to the American Lung Association. The number of cases doubled between 1980 and 1995, prompting the U.S. Department of Health and Human Services to classify the disease as an epidemic in 2000.

During an attack, sufferers tend to hyperventilate, breathing fast and deep against constricted airways to fight an overwhelming feeling of oxygen deprivation.

Unfortunately, this makes the problem worse by lowering the body’s carbon dioxide levels, which restricts blood flow to the brain and can further irritate already hypersensitive bronchial passages.

Patients who “overbreathe” on a sustained basis risk chronic CO₂ deficiencies that make them even more vulnerable to future attacks. Rescue medications that relieve asthma symptoms do nothing to correct breathing difficulties associated with hyperventilation.

As part of SMU’s Stress, Anxiety and Chronic Disease Research Program, Ritz and Meuret use their biofeedback-based Capnometry-Assisted Respiratory Training (CART) to teach asthma patients to normalize and reverse chronic overbreathing. A hand-held device called a capnometer measures the amount of CO₂ exhaled. Using this device, patients learn how to breathe more slowly, shallowly and regularly.

Mueret4a%2C-9-09%2Clr.jpg CART techniques could have a positive impact on quality of asthma treatment even as they reduce the need for acute care, Ritz says.

“The research shows that this kind of respiratory therapy can limit both the severity and frequency of asthma attacks,” he says. “That means fewer doctor visits and less frequent use of rescue medications, with the associated savings of both time and money.”

And for those who count any year without a trip to the emergency room as a year with a good treatment outcome, that means a higher quality of life, says Meuret, who lives with asthma herself.

“The training gives patients new ways to deal with acute symptoms, and that helps them to feel more in control,” she says. — Kathleen Tibbetts

(Photos: SMU Professor Alicia Meuret uses biofeedback data to demonstrate the relationship between oxygen and carbon dioxide levels in hyperventilation.)

News coverage:
ScienceDaily
physorg.com
Health.am
e! Science News
RTMagazine.com
medindia.net
Bio-Medicine.org
medicalnewstoday.com

Tags Alicia E. Meuret, Dedman College, SMU Department of Psychology, Thomas Ritz

Health & Medicine Researcher news Technology

LA Times: Does amputee sprinter Pistorius have competitive edge?

Post author By Margaret Allen
Post date July 1, 2009

Peter Weyand, an SMU associate professor of applied physiology and biomechanics, was part of a team of experts in biomechanics and physiology that conducted experiments on Oscar Pistorius. The South African bilateral amputee track athlete has made world headlines trying to qualify for races against runners with intact limbs, including the Olympics.

The team just released their full findings in the “Journal of Applied Physiology.” Some of the findings were previously confidential and are being released now for the first time. The findings were presented earlier to the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland in May of 2008.

Reporter Jeannine Stein of the Los Angeles Times reported July 1 on the new findings.

Excerpt:

By Jeannine Stein
Los Angeles Times
Oscar Pistorius is faster on two prosthetic legs than many are on two intact legs, which makes some people believe those legs give the South African athlete an advantage.

While controversy has been simmering about the curved “Cheetah” carbon fiber legs for some time, a new study comparing various aspects of his athletic performance with able-bodied runners sheds some light on the situation. Ultimately, however, it might also make things even muddier.

Pistorius has competed (and won medals) for years in the Paralympics, but in 2007 he ran in an international competition against able-bodied runners. That year the International Assn. of Athletics Federations placed a ban on technical devices incorporating springs, wheels or other elements that could give a benefit to the user, although it denied the ban was linked to Pistorius.

Read the full story.

Tags Annette Caldwell Simmons School of Education & Human Development, Peter Weyand

Health & Medicine Technology

Released: Previously confidential study results of amputee sprinter Oscar Pistorius

Post author By Margaret Allen
Post date June 24, 2009

A team of experts in biomechanics and physiology that conducted experiments on Oscar Pistorius, the South African bilateral amputee track athlete, have just released their findings in the “Journal of Applied Physiology.” Some of their previously confidential findings were presented to the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland in May of 2008. Other findings are now being released for the first time.

A portion of the team’s findings had been presented at the CAS to appeal the eligibility ban that had been imposed on Pistorius by the International Association of Athletics Federations (IAAF) barring him from sanctioned competitions, including the Olympics and World Championships.

The IAAF had claimed that the Cheetah Flex-Foot prostheses (J-shaped, high-performance prostheses used for running) worn by Pistorius give him an advantage over able-bodied runners.

“I am pleased that we can now completely disclose our results as our study includes critical new data not presented in the CAS eligibility hearing,” said Peter Weyand, lead author of the study and an associate professor of applied physiology and biomechanics at SMU.

Photo: Weyand observes Pistorius on treadmill (Credit: Jeff Fitlow/Rice)

“In addition to informing an interested public, full disclosure is in the best interests of Oscar Pistorius, other athletes and the sport of Track and Field,” Weyand said. “The controversy raised by Oscar’s inspiring performances presents a pivotal case for the future regulation of prosthetic and other technology in organized athletics. Accordingly, disseminating all the available facts is essential, and I am relieved that all of our data are now available, particularly the mechanical data that are most relevant to the controversy and which were not part of the CAS hearing.”

The eligibility ban appeal was successfully presented on behalf of Pistorius by the international law firm of Dewey & LeBoeuf who took the case on a pro-bono basis.

The CAS concluded that the IAAF failed to prove that the biomechanical effects of the Cheetah prostheses give Pistorius an advantage over other athletes not using the prostheses.

The authors of the study are Weyand of Southern Methodist University; Matthew Bundle of the University of Wyoming; Craig McGowan of the University of Texas at Austin; Alena Grabowski and Hugh Herr of the Massachusetts Institute of Technology; Mary Beth Brown of Georgia Institute of Technology; and Rodger Kram of the University of Colorado at Boulder.

None received compensation for the research or work on behalf of the CAS hearing. The group agreed to conduct the experiments with the understanding that they would be able to publish their scientific findings after the CAS hearing.

The experiments were conducted at the Rice University Locomotion Laboratory in Houston.

The scientific team compared Oscar Pistorius to track athletes with intact limbs to evaluate their: energy cost of running; fatigue resistance; and sprinting mechanics.

The team concluded that:

Pistorius’ energy cost of running is similar to that of accomplished male distance runners, but 17 percent lower than that of performance-matched male sprinters.
Pistorius’ ability to hold his speed over longer sprint races is identical to that of intact-limb athletes.
Pistorius’ sprinting mechanics are markedly dissimilar to intact-limb track athletes. At top speed:
- Pistorius exerts considerably less force on the ground in relation to his body weight than intact-limb runners.
- His foot is in contact with the ground 14 percent longer on each sprinting step.
- He spends 34 percent less time in the air between steps.
- He takes 21 percent less time to reposition (swing) his legs between steps.

In summary, the team concluded that Pistorius’ physiology — energy cost and fatigability &#8212 is generally similar to that of intact-limb athletes, but his sprint running mechanics are markedly dissimilar.

The group’s paper in the “Journal of Applied Phsyiology” concludes:

“The mechanical dissimilarities observed between Pistorius and intact-limb runners result from functional trade-offs that are perhaps inevitable for artificial vs. biological limbs. The aerial and swing time reductions observed for Pistorius may be due to his light-weight prostheses. However, the meager forces he exerts on the ground may be a critical limitation for speed. Legs must perform different functions during the stance and swing phases of the stride, as well as during the start, acceleration and relatively constant-speed phases of sprint running. Collectively, the results underscore the difficulty of providing these multiple mechanical functions with a single, relatively simple prosthetic design, and the formidable challenges involved in engineering limbs that fully mimic those produced by nature.”

The study results were posted June 18 to the online site of the “Journal of Applied Physiology.” Read the article.

Pistorius competes in the 100-meter and 400-meter sprints. The Cheetah legs have earned him the nickname “blade runner.” While his time was such that he just missed qualifying for the 2008 Beijing Olympics, Pistorius reportedly will try to compete in the London Olympics in 2012.

Weyand is an associate professor of applied physiology and biomechanics in SMU’s Department of Applied Physiology and Wellness in the Annette Caldwell Simmons School of Education and Human Development.

Tags Annette Caldwell Simmons School of Education & Human Development, Peter Weyand

Health & Medicine Learning & Education Mind & Brain

Déjà Vu research pushes around memory, creates illusion of past encounter

Post author By Margaret Allen
Post date June 19, 2009

Brown%2C%20Alan2%206-19-09%20photoshopped.jpg

A new study by research psychologists Alan S. Brown of SMU and Elizabeth Marsh of Duke University provides new clues about déjà vu, that eerie sense of experiencing a moment for the second time.

These clues, in turn, could help unlock the secrets of the human brain.

“Déjà vu is inappropriate behavior by the brain,” says Brown, professor in SMU’s Department of Psychology and a leading researcher on memory. “By shedding light on this odd phenomenon, we can better understand normal memory processes.”

Published in the May issue of “Psychological Science,” the study significantly extends research on the déjà vu theory of “double perception,” which suggests that a quick glance at a scene can make it appear strangely familiar when it is fully perceived moments later.

“This is easy to imagine in today’s distracted society,” Brown says. “Let’s say you enter a new museum, glancing at artwork while talking on your cell phone. Upon hanging up, you look around and sense you’ve been there long ago.”

According to double perception theory, the initial glance created a mushy memory without time-space context, Brown says. “When you then consciously register the scene, the brain connects the two memories — and you get that spooky feeling.”

Brown and Marsh re-created this experience in the laboratory using unique symbols. In their trials, a symbol was flashed at a subliminal level on a computer screen, followed by a longer view of the same or a different symbol, or no symbol.

When a flash was followed by its identical symbol, participants were five times more likely to say they had seen that symbol sometime before the experiment.

“We pushed memory around,” Brown says. “We changed people’s views of their personal past by instilling a false sense of a previous encounter.”

In pushing its participants’ memories to a time and place outside the laboratory, the new study goes beyond the few previous studies of double perception that have been conducted in the past 100 years. Those studies used words or names, rather than symbols.

“Words and names are contaminated because study participants actually could have encountered them before the experiment,” Brown says, “but it’s extremely unlikely that they ever had encountered our symbols. Our study more closely parallels a quick glance at an unfamiliar object in the real world.”

In addition to double perception, researchers have other theories about the cause of déjà vu, which is French for “already seen.” These theories include a brief dysfunction in the brain, such as a seizure, and “episodic familiarity,” when a forgotten memory connects with part of the present experience.

Brown and Marsh tested episodic familiarity in a 2008 study published in “Psychonomic Bulletin & Review,” in which participants were quickly shown photos of college campuses they had never visited. Upon returning to the laboratory several weeks later, they viewed a series of new and old campus photos and judged whether they had been to the locations. The study showed that the initial brief exposure increased participants’ beliefs that they had visited these colleges — when, in fact, they hadn’t.

“Déjà vu is such a rare event, with potentially numerous causes,” Brown says. “If we can nudge people a little bit in that direction, we can learn the mechanisms behind it.” — Sarah Hanan

Tags Alan S. Brown, Dedman College, Elizabeth Marsh, SMU Department of Psychology

Health & Medicine Mind & Brain

Chemical exposure now linked to Gulf War syndrome

Post author By Margaret Allen
Post date March 20, 2009

The following story published March 20, 2009 on www.sciencedaily.com

A new study by researchers from UT Southwestern Medical Center and Southern Methodist University is the first to pinpoint damage inside the brains of veterans suffering from Gulf War syndrome. The finding links the illness to chemical exposures and may lead to diagnostic tests and treatments.

Robert Haley, chief of epidemiology at UT Southwestern and lead author of the study, said the research uncovers and locates areas of the brain that function abnormally. Recent studies had shown evidence of chemical abnormalities and shrinkage of white matter in the brains of veterans exposed to certain toxic chemicals, such as sarin gas during the 1991 Persian Gulf War.

The research, was published in the March issue of the journal “Psychiatry Research: Neuroimaging.” Imaging enables investigators to visualize exact brain structures affected by these chemical exposures, Haley said.

Richard Gunst, Wayne Woodward and William Schucany, professors in SMU’s Statistical Science Department in Dedman College, are collaborating with the imaging specialists at UT Southwestern Medical Center to compare brain scans of veterans with the syndrome against a healthy control group.

“Before this study, we didn’t know exactly what parts of the brain were damaged and causing the symptoms,” Haley said.

Richard Gunst

“We designed an experiment to test areas of the brain that would have been damaged if the illness was caused by sarin or pesticides, and the results were positive,” he said.

In designing the study, Haley and his colleagues reasoned that if low-level sarin or pesticides had damaged Gulf War veterans’ brains, a likely target of the damage would be cholinergic receptors on cells in certain brain structures. If that was so, administering safe levels of medicines that stimulate cholinergic receptors would elicit an abnormal response in ill veterans.

In the study, 21 chronically ill Gulf War veterans and 17 well veterans were given small doses of physostigmine, a substance which briefly stimulates cholinergic receptors. Researchers then measured the study participants’ brain cell response with brain scans.

Pictured right: Wayne Woodward

“What we found was that some of the brain areas we previously suspected responded abnormally to the cholinergic challenge,” Haley said. “Those areas were in the basal ganglia, hippocampus, thalamus and amygdala, and the thalamus. Changes in functioning of these brain structures can certainly cause problems with concentration and memory, body pain, fatigue, abnormal emotional responses and personality changes that we commonly see in ill Gulf War veterans.”

A previous study funded by the U.S. Army found that repetitive exposure to low-level sarin nerve gas caused changes in cholinergic receptors in lab rats.

“An added bonus is a statistical formula combining the brain responses in 17 brain areas that separated the ill from the well veterans, and three different Gulf War syndrome variants from each other with a high degree of accuracy,” Haley said. “If this finding can be repeated in a larger group, we might have an objective test for Gulf War syndrome and its variants.”

An objective diagnostic test, he said, sets the stage for ongoing genetic studies to see why some people are affected by chemical exposures, and why others are not.

New studies would also allow the selection of homogenous groups of ill veterans in which to run efficient clinical trials for treatments. Haley first described Gulf War syndrome in a series of papers published in January 1997 in the “Journal of the American Medical Association.”

William Schucany

In previous studies, research from Haley showed that veterans suffering from Gulf War syndrome had lower levels of a protective blood enzyme called paraoxonase, which usually fights off the toxins found in sarin.

Veterans who served in the same geographical area and did not get sick had higher levels of this enzyme.

Haley and his colleagues have closely followed the same group of tests subjects since 1995. In 2006, UT Southwestern and the Department of Veterans Affairs established a dedicated, collaborative Gulf War illness research enterprise in Dallas, managed by UT Southwestern.

Texas Sen. Kay Bailey Hutchison, a longtime supporter of Gulf War research, facilitated that agreement and secured a $75 million appropriation over five years for Gulf War illness research.

The study was funded, in part, by the U.S. Army Medical Research and Materiel Command.

Other UT Southwestern researchers involved in the study included Jeffrey Spence and Patrick Carmack, assistant professors of clinical sciences; Michael Devous and Frederick Bonte, professors of radiology; and Madhukar Trivedi, professor of psychiatry.

Tags Dedman College, Richard Gunst, Robert Haley, SMU Department of Statistical Science, Wayne Woodward, William Schucany