Science Tracks How the Brain's 'Clock' Ticks

(HealthDay News) -- Scientists have developed a new model of how the brain tells time, which challenges the popular theory of an internal clock that generates and counts regular fixed moments.

Researchers at the University of California, Los Angeles, suggest that a series of physical changes to the brain's cells help it track the passage of time.

"If you toss a pebble into a lake, the ripples of water produced by the pebble's impact act like a signature of the pebble's entry time. The farther the ripples travel, the more time has passed," Dean Buonomano, associate professor of neurobiology and psychiatry at the David Geffen School of Medicine at UCLA, said in a prepared statement.

"We propose that a similar process takes place in the brain that allows it to track time. Every time the brain processes a sensory event, such as a sound or flash of light, it triggers a cascade of reactions between brain cells and their connections. Each reaction leaves a signature that enables the brain-cell network to encode time," said Buonomano, who is also a member of UCLA's Brain Research Institute.

Using a computer model, the researchers demonstrated that this kind of network could tell time. Their new model is outlined in an article in the Feb. 1 issue of the journal Neuron.

"The value of this research lies in understanding how the brain works. Many complex human behaviors -- from understanding speech to playing catch to performing music -- rely on the brain's ability to accurately tell time. Yet no one knows how the brain does it," Buonomano said.

More information
The U.S. Institute of Mental Health explains how biological clocks work.

Alphanate Approved for Clotting Disorder

(HealthDay News) -- The U.S. Food and Drug Administration has approved a biologic product called Alphanate for people with a bleeding disorder called von Willebrand disease (vWD) who require surgery.

People with vWD, the most common inherited bleeding disorder affecting about 1 percent of the U.S. population, have a missing or ineffective hormone called desmopressin. In most cases, people with the clotting disorder do not require treatment to stop bleeding after an injury or surgery, the FDA said.

But for some 2,000 people in the United States with moderate-to-severe forms of the disease, bleeding can be excessive if not treated.

Alphanate is made from purified human plasma that has been screened for blood-borne viruses, the agency said in a statement. But it conceded that transmission of certain viruses "while very low, cannot be totally eliminated."

Alphanate, made by Los Angeles-based Grifols Biologicals Inc., is already approved for other bleeding disorders including hemophilia A, the agency said.

More information
To learn more about vWD, visit the U.S. National Heart Lung and Blood Institute.

Conflicting Attitudes Hinder Women's Help in Clinical Trials

(HealthDay News) -- Conflicting attitudes may limit the participation of some groups of women in clinical trials, suggests a Wake Forest University School of Medicine study.

Researchers discussed clinical trials with 72 women (52 black women from different income levels and 20 low-income white women) and found that the women expressed uncertainties about trusting study investigators and fears about the trial itself, along with hopes that the research would help medical progress.

"The results of our study demonstrate the willingness of at least some African-American and low socioeconomic status white women to participate in research if it will benefit them or their families, advance scientific knowledge and help others in the future," the study authors wrote.

"But they must trust the researchers to be ethical and upfront with them about what is required, fully disclose what will happen to the health information they provide, and put their best interests first."

The researchers found that the women's fears were based on "not wanting to be a guinea pig or doing something that no one has done before."

The study is published in the February issue of the Journal of Health Care for the Poor and Underserved.

In order to alleviate the kinds of fears and concerns about clinical trials expressed by the women, the researchers suggested that academic medical centers boost their involvement with minority or low socioeconomic communities in order to make those people partners in research designed to help address their health problems and concerns.

More information
The U.S. National Institutes of Health has more about clinical trials.

Workouts Add Muscle to the Flu Shot

(HealthDay News) -- Pumping iron may pump up your response to a flu shot, British research suggests.

A study of 60 college students concluded that a brief muscle-building session before a flu shot can enhance the immune system's response to the vaccine. However, men and women had different responses.

In the study, the students either rested quietly or did upper arm exercises for about 25 minutes. Six hours later, all the students received a flu shot.

Over the next five months, blood samples were taken from the students in order to measure cellular immune response and longer-lasting development of antibodies to the viruses in the flu vaccine.

The cell-mediated response remained unchanged in women who exercised, while it increased in males. Antibody response was higher in women who exercised but was lower in men.

"We're trying to find something that could be very simple to do, which would benefit your vaccine response," study lead author Kate Edwards, of the University of Birmingham, said in a prepared statement.

The findings from this study help confirm earlier research by Edwards' team that found that the acute stress of exercise can enhance antibody production in humans.

The findings are published in the February issue of the journal Brains, Behavior and Immunity.

More information
The U.S. Centers for Disease Control and Prevention offers these flu prevention tips.