October 24, 2006, 5:48 PM CT

Virtual Colonoscopy More Expensive

Wake Forest University Baptist Medical Center researchers have found that "virtual" colonoscopy using a computer tomography (CT) scanner is considerably more expensive than the traditional procedure due to the detection of suspicious images outside of the colon.

"Virtual colonoscopy will certainly play a role in the future of colon cancer screening," said gastroenterologist Richard S. Bloomfeld, M.S., M.D., assistant professor of medicine at Wake Forest Baptist and a member of the research team. "It is important to understand the implications of findings outside the colon before we advocate wide-spread use of this technology".

Virtual colonoscopy, also known as CT-colonography (CTC), was developed at Wake Forest Baptist. It allows doctors to use CT scanners to look at the colon to detect polyps (small growths in the colon that may become cancerous if they are not removed) and cancers. Virtual reality software allows them to look inside the body without having to insert a long tube (conventional colonoscopy) into the colon or without having to fill the colon with liquid barium (barium enema).

Research performed at Wake Forest Baptist and elsewhere has shown that CTC is better able to see polyps than barium enemas and is nearly as accurate as conventional colonoscopy. Most patients report that CTC is more comfortable than either procedure.........

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October 22, 2006, 8:13 PM CT

Heart Surgery For Atrial Fibrillation Simplified

Heart surgeons at Washington University School of Medicine in St. Louis have helped usher in a new era in the surgical treatment of atrial fibrillation. Using radiofrequency devices - rather than a scalpel - they've greatly shortened the surgery and made it significantly easier to perform.

"Because of the devices, the procedure - called the Cox-Maze procedure - has gone from an operation that hardly anyone was doing to one that 80 to 90 percent of U.S. heart surgeons are now performing," says Ralph J. Damiano Jr., M.D., the John Shoenberg Professor of Surgery and chief of cardiac surgery at the School of Medicine and a cardiac surgeon at Barnes-Jewish Hospital.

Adults older than 40 have a 25 percent risk of eventually developing atrial fibrillation in which the upper chambers of the heart twitch rapidly instead of contracting fully and regularly. The condition can lead to stroke or heart failure.

For some patients, medications can control the abnormal heart rhythms and the risk of clotting associated with atrial fibrillation, but they do not cure the disorder. The Cox-Maze procedure has a greater than 90 percent cure rate.

Damiano and his colleagues have played a vital role in the development and testing of radiofrequency devices for treating atrial fibrillation. The devices deliver high-energy radiofrequency waves to heart tissue and very quickly create scars or ablations, which replace most of the complex incisions required by the Cox-Maze procedure. The ablations disrupt the atria's abnormal electrical activity and normalize heart rhythm.........

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October 19, 2006, 9:36 PM CT

Immune System And Fight Against TB

A key aspect of how the body kicks the immune system into action against tuberculosis is revealed in research published recently. The authors, writing in Science, hope that their research could aid the development of novel vaccines and immunotherapies to combat TB, which is responsible for two million deaths each year.

The cause of TB is a slow-growing bacterium known as Mycobacterium tuberculosis. Scientists have known for some time that when host cells are invaded by this bacterium, the host cells are able to call up additional immune cells such as lymphocytes to fight them and try to limit the damage which the bacteria can cause.

The new research, by scientists from Imperial College London, the Universities of Cambridge and Oxford, and other international institutions, identifies a receptor on the host cells which triggers the immune cells' response to tuberculosis. The scientists demonstrated that without this receptor, known as CCR5, mycobacteria were able to thrive inside host cells, as the immune cells did not receive the signal from CCR5 to attack them.

The scientists hope that their findings could enable a novel vaccine or immunotherapy to be developed which could artificially kick the immune cells into action in the same way as CCR5. This could boost the immune response to TB.........

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October 19, 2006, 8:59 PM CT

Affymetrix 500K Array And Memory Gene

Affymetrix Inc. announced recently that scientists at the Translational Genomics Research Institute (TGen) in Phoenix, Arizona have used the Affymetrix 500K Array to discover a gene--called Kibra--linked to memory performance in humans. The team's findings may be used to develop new medicines for memory-based diseases such as Alzheimer's and Parkinson's by providing researchers with a better understanding of how memory works at the molecular level.

The study entitled, "Common KIBRA alleles are linked to human memory performance," would be reported in the Oct. 20, 2006 issue of Science. The research team was led by Dietrich Stephan, Ph.D., director of TGen's Neurogenomics Division. It included colleagues at the University of Zurich in Switzerland, Banner Alzheimer's Institute and Mayo Clinic Scottsdale.

"Using the latest Affymetrix 500K Array, we have shed light on the fundamental biological process of human memory performance," said Dr. Stephan. "We can use this new understanding to develop drugs that will improve memory function."

Until now, scientists did not have access to the high-density technology needed to examine the genetic components linked to memory performance. The team at TGen used Affymetrix Human Mapping 500K Arrays to analyze 500,000 DNA markers simultaneously, providing a genetic blueprint for the memory-study participants. The scientists discovered the Kibra gene by comparing the genetic blueprints of people with good memory vs. poor memory and looking for the genetic variations consistently present in one group, but not the other. They then validated their discovery by replicating the Kibra gene finding in two separate and distinct groups of subjects.........

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October 17, 2006, 9:22 PM CT

Virtual Colonoscopy saves lives

Three-dimensional computed tomography (CT) colonography, also known as virtual colonoscopy, is an accurate screening method for colorectal cancer, according to a study published in the recent issue of the journal Radiology. In addition, when covered by third-party payers, virtual colonoscopy may entice more people to be screened.

"Our positive experience with virtual colonoscopy screening covered by health insurance demonstrates its enormous potential for increasing compliance for colorectal cancer prevention and screening," said lead author Perry J. Pickhardt, M.D., associate professor of radiology at The University of Wisconsin Medical School in Madison. "In addition, recent technical improvements have resulted in even better performance results".

Colorectal cancer remains the second leading cause of cancer mortality in the United States, and the American Cancer Society (ACS) estimates that there will be 148,610 new cases diagnosed in 2006 and 55,170 deaths. The disease is largely preventable through screening for colon polyps, which are non-cancerous growths that may develop into cancer if not removed. ACS recommends that people at average risk for colorectal cancer begin regular colorectal cancer screening at age 50, but current compliance with this recommendation remains well below 50 percent. Many people resist screening because of the discomfort and inconvenience caused by the standard optical colonoscopy test.........

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October 16, 2006, 10:10 PM CT

Prescription Pain Medication Abuse On Increase

Researchers at Rush University Medical Center found prescription pain medicine (PPM) abuse is a rapidly growing problem with surprising and often unpredictable distribution patterns. The research was presented at the Annual Meeting of the American Society for Anesthesiologists in Chicago, October 13, 2006.

Mario Moric, PhD, a researcher in the department of Anesthesiology at Rush, and colleagues used survey data from the National Survey on Drug Use and Health for 2002-04 to estimate the prevalence of drug abuse across the United States for various illicit and prescription substances.

Moric found that PPM abuse did not follow traditional patterns. "Individual states with high levels of PPM abuse may not recognize the problem. The prevailing assumption that only those states with high levels of traditional illicit drug abuse should be vigilant is clearly misleading".

The researchers found distribution of PPM abuse across the United States varied greatly and differed from other seemingly similar drug abuse trends. PPM distribution differed substantially from inhalants, heroin and sedatives, was somewhat similar to cocaine and stimulants and was closely related to distribution of tranquilizers.

Furthermore, the researchers found that states with large metropolitan areas (New York, Illinois, Texas and California) did not have a high distribution of abuse, despite the common view that drug abuse is associated with the fast-paced lifestyle of city dwellers.........

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October 16, 2006, 9:53 PM CT

Women On Hormone Therapy Sensitive To Negative Events

Older women on hormone therapy are more sensitive to negative events, confirming speculation that age-related estrogen loss affects the brain's ability to process emotion, an Oregon Health & Science University study shows.

But that sensitivity to negative emotional events, such as viewing a photograph of a dead person, doesn't necessarily mean women taking estrogen remember those events any better.

In the study by researchers in the Cognition & Aging Laboratory at the OHSU School of Medicine's Department of Behavioral Neuroscience, hormone therapy in women appears to reverse the age-related loss of arousal to negative emotional events experienced by the elderly. It also points to specific changes in the brain's arousal system, in the regions that process emotion, and intensification of negative emotions.

The results were presented today at Neuroscience 2006, the Society for Neuroscience's 36th annual meeting at the Georgia World Congress Center in Atlanta.

Scientists have suspected a link between sex hormones and emotion. Strengthening this theory is the fact that brain regions tuned for processing emotion and storing emotional memory - the amygdala and hippocampus - also respond to sex hormones and contain hormone receptors. Thus, changes in "emotional enhancement" people experience as they age, including a reduction in the ability to remember negative events, may be modified by age-related loss of sex hormones or hormone therapy.........

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October 15, 2006, 7:26 PM CT

Promise For Herpes Vaccine

A study by a Montana State University researcher suggests a new avenue for developing a vaccine against genital herpes and other diseases caused by herpes simplex viruses.

As per a research findings published earlier this year in the Virology Journal, MSU virologist William Halford showed that mice vaccinated with a live, genetically-modified herpes simplex virus type 1 (HSV-1) showed no signs of disease 30 days after being exposed to a especially lethal "wild-type" strain of the virus.

In contrast, a second group of mice that received a more conventional vaccine died within six days of being exposed to the same "wild-type" strain.

"We have a clear roadmap for producing an effective live vaccine against genital herpes," said Halford, who works in MSU's Department of Veterinary Molecular Biology. "Eventhough my studies were performed with HSV-1, the implications for HSV-2-induced genital herpes are clear. Overall the two viruses are about 99 percent genetically identical".

An estimated 55 million Americans carry herpes simplex virus type 2 (HSV-2), which causes genital herpes. Infection is life-long. Approximately 5 percent of those with genital herpes - 2 million to 3 million Americans - suffer outbreaks one to four times annually. A vaccine offering life-long protection does not exist.........

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October 15, 2006, 7:10 PM CT

Adolescent And Fluoxetine

A new study offers clues as to why some teenagers taking common anti-depressants may become more aggressive or kill themselves. The research is published in the October Behavioral Neuroscience, which is published by the American Psychological Association (APA).

Neuroscientists at the University of Texas at Austin found that juvenile hamsters given low doses of fluoxetine hydrochloride, which is sold in the United States as Prozac, became more aggressive on low doses of the drug. Juveniles given high doses became somewhat less aggressive, but not as much as adult hamsters, who calmed down on both high and low doses.

Doctoral student and lead author Kereshmeh Taravosh-Lahn, BA, says the findings confirm that juvenile and adult brains are different. Thus, she says, "It is unwise to expect a drug to work the same in juveniles as in adults." .

Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), is the only medicine approved to treat depression in children and adolescents. However, it has carried an FDA "black box" warning since Fall 2004 due to findings of increased risk of suicidal thoughts and behaviors in some children and adolescents on the drugs. Fluoxetine affects the regulation of serotonin, a naturally occuring neurotransmitter thought to be involved in depression, by keeping it available longer in the brain's synapses. It is known to inhibit aggression in adult hamsters. Hamsters are often used as an animal model for studying the neural basis of social behavior, given how the rodents' youthful play fighting develops in clearly understood stages into adult aggression.........

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October 15, 2006, 6:49 PM CT

High Blood Sugar Level Before Surgery Is Dangerous

Patients who have high blood sugar before undergoing surgery run an increased risk of developing blood clots, deep vein thrombosis and even pulmonary embolism after surgery.

Boris Mraovic, M.D., assistant professor of anesthesiology in the Artificial Pancreas Center at Jefferson Medical College of Thomas Jefferson University in Philadelphia, and his colleagues examined records of nearly 6,500 hip or knee replacement surgery patients at Thomas Jefferson University Hospital who were admitted between 2003 and 2005. They asked what happened to patients with high blood sugar that wasn't well controlled prior to surgery.

Of these patients, 38 had very high blood glucose more than 250 mg/dl on the day of preoperative testing and the day of surgery. The team found that approximately 10.5 percent of the patients with high blood sugar developed a pulmonary embolism, a life-threatening condition in which blood clots travel to the lungs, after surgery, a rate that is 6.2 times greater than would be expected in the general population. The researchers report their results on October 15, 2006 at the annual meeting of the American Society of Anesthesiologists in Chicago.

"These data suggest that if an individual has high blood glucose and is coming for surgery, he or she should correct it first and probably postpone the surgery," says Dr. Mraovic.........

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