Scientists Find Molecular Similarities in Brains of Those With Autism

WEDNESDAY, May 25 (HealthDay News) -- The symptoms and severity of autism vary widely, but new research shows remarkable similarities at the molecular level in the brains of people with the disorder.

Researchers from Los Angeles, Toronto and London analyzed post-mortem brain tissue samples from 19 people with autism and 17 without.

In the healthy brains, researchers saw distinct differences in the gene expression in the frontal lobe vs. the temporal lobe of the cerebral cortex -- differences that help determine the structure and function of the two brain regions.

Specifically, between the frontal and temporal lobes in the healthy brains, more than 500 genes were expressed at different levels. Gene expression is the process by which a gene's DNA sequence is copied into RNA to produce proteins, which perform specific tasks within the cell.

But researchers didn't find those same patterns in autistic brains. Instead, researchers found only eight differences in the gene expression in the frontal and temporal lobes.

"In a healthy brain, the frontal and temporal lobes can be differentiated," said principal investigator Dr. Daniel Geschwind, a distinguished professor of neurology, psychiatry and human genetics at the David Geffen School of Medicine at UCLA. "But in autism we didn't see that. Instead, the frontal lobe closely resembles the temporal lobe."

Many of those regional differences in the cerebral cortex are established during fetal development, researchers added.

The study is published in the May 25 online issue of Nature.

Over the past decade, researchers have discovered lots of gene variants that seem to play a role in some cases of autism, but none of the mutations were present in a large percentage of people with the disorder.

Prior research has also implicated regions of the cerebral cortex, which is highly developed in humans, in autism. The frontal lobe is involved with judgment, language, planning, social cognition and personality, while the temporal lobe is important for language and emotions, Geschwind said.

But this is the first study to show differences in the patterns of gene expression between brain regions. It's those patterns of gene expression that enable the brain to function normally and to communicate properly with other regions of the brain, explained Robert Ring, vice president for translational research for Autism Speaks.

"This study allows us to look at the complexity of what's going on at a molecular level in the brain, a step up from the gene," Ring said. "Here we have the opportunity to really see that the development of normal brain physiology requires differences in the regional activity of gene networks. This report provides evidence that the expected pattern of these differences is absent in autism."

Researchers say the findings may help in the development of medications that target the pathways. "The fact that it's shared says there is some hope of beginning to unwind this and develop some treatments that would target those pathways," Geschwind said.

Compared to the healthy brains, autistic brains had less activity in the genes responsible for neuron function and communication, and a heightened level of gene expression in genes involved in immune function and inflammatory response.

Some of those genes have also previously been implicated in autism, researchers noted.

An estimated one in 110 U.S. children -- including one in 70 boys -- has an autism spectrum disorder, according to background information in the study. Autism affects behavior and impairs the ability to communicate and establish social relationships. Diagnoses have increased tenfold in the past decade.

More information

The U.S. National Institutes of Health has more on autism.

SOURCES: Daniel Geschwind, M.D., Ph.D., distinguished professor, neurology, psychology and human genetics, University of California, Los Angeles; Robert Ring, Ph.D., vice president, translational research, Autism Speaks, New York City; May 25, 2011, online, NatureCopyright

Blood Pressure Drug Helps Those With Mild Heart Failure

SUNDAY, May 22 (HealthDay News) -- New Swedish research suggests that the drug Inspra reduces the threat of major cardiovascular complications among patients who have a mild form of heart failure.

This latest finding builds on earlier work that was published by the New England Journal of Medicine last fall. That study suggested that Inspra (eplerenone), an aldosterone antagonist, helps control cardiovascular complications among patients with a history of serious chronic heart failure.

Since far more people suffer from mild heart failure, this new finding could mean the drug might benefit a far broader group of patients, the researchers added.

The Swedish analysis makes an even stronger case for the use of Inspra in patients with mild heart failure because, in addition to reducing mortality, it also reduces the incidence of the irregular heart beat condition known as atrial fibrillation, study co-author Karl Swedberg, from the University of Gothenburg in Sweden, said in a news release from the European Society of Cardiology.

Atrial fibrillation "is a condition which both increases morbidity and complicates the care of patients with heart failure," he explained.

Swedberg and his colleagues were slated to present the findings Sunday in Gothenburg at the Heart Failure Congress 2011, organized by the Heart Failure Association of the European Society of Cardiology.

The study team noted that Inspra is currently approved for the control of high blood pressure as well as for the treatment of heart attack patients who experience congestive heart failure. It is not yet approved for the treatment of patients who experience mild heart failure. It is available generically in the United States, according to the news release.

Experts estimate that almost 6 million people in the United States suffer from heart failure.

The current finding stems from a re-analysis of a larger study that involved more than 2,700 heart failure patients being cared for at 278 different health centers.

Focusing specifically on those participants who had experienced mild (class 2) heart failure, the authors found that just 2.7 percent of those patients who were placed on a regimen of between 25 milligrams to 50 milligrams daily of Inspra for a little less than two years experienced atrial fibrillation.

This compared with 4.5 percent of those patients who were randomized to receive a sugar pill instead.

Dr. Byron K. Lee, director of the Electrophysiology Laboratories and Clinics within the division of cardiology at the University of California, San Francisco, noted that exactly how Inspra seems to help heart patients is not well understood.

"It is unclear how eplerenone works to lower the risk of abnormal heart rhythms like atrial fibrillation and atrial flutter," he said. "However, there are many potential mechanisms. One possibility is that eplerenone may help maintain potassium levels. Patients with heart failure are often on high-dose diuretics that remove fluid at the expense of removing potassium. Thats why heart failure patients need to watch their potassium level vigilantly."

More information

For more on atrial fibrillation, go to National Library of Medicine.

SOURCE: Byron K. Lee, M.D., director, Electrophysiology Laboratories and Clinics, division of cardiology, University of California, San Francisco; European Society of Cardiology, news release, May 22, 2011Copyright