The low-pathogenic avian influenza virus commonly occurs in nature, but usually results in minor sickness or no noticeable disease for birds.

Low-pathogenic bird flu has been confirmed in the United States this year including in Michigan, Montana, Pennsylvania and Maryland.

In an effort to detect the high-pathogenic H5N1 strain that has killed 151 people overseas, USDA and the Department of the Interior are working with the states to collect between 75,000 and 100,000 wild bird samples in addition to more than 50,000 environmental tests throughout the United States.

"Just remember that a hamster is a hamster is a hamster," said Dr. Jon Shaw, director of child and adolescent psychiatry at the University of Miami Miller School of Medicine.

"There are a lot of studies on the maturation and evolution of the central nervous system structure through adolescence, and nobody thinks the adult brain is [the same as] the child's brain," Shaw added. "And this just reminds us that other studies are needed to try and understand what the difference means in terms of metabolism of drugs."

In October 2004, the U.S. Food and Drug Administration directed manufacturers of SSRIs, which include Celexa, Paxil, Prozac and Zoloft, to put a special "black-box" warning on the drugs' labeling. The warning alerts health-care providers about an increased risk of suicidality in children and teens using the medications.

In July 2005, the FDA issued a public health advisory that raised the possibility the risk of suicidality also applied to adults taking SSRIs, after several studies pointed to that possibility.

Other studies have found a lower incidence of youth suicide related to Prozac and other SSRIs. Prozac is the only medication approved to treat depression in children and adolescents.

Researchers at the University of Texas at Austin injected hamsters with either high or low doses of Prozac in the latest study.

They created a threatening situation two hours later by putting a younger hamster in the home cage of another same-sex hamster for 10 minutes. Usually, male hamsters respond to such situations with aggression.

In these scenarios, the adult hamsters injected with either the high or low dose of Prozac were calmer.

Juvenile hamsters, however, reacted differently to the different doses. Those on low doses were more aggressive while those on higher doses were less aggressive, though still not as calm as the adults.

"We do know from adolescent studies that the brain continues to mature during adolescence, and even the early adult years," Shaw said. "So, this study is an important study in that it reminds us that further research is really necessary to look at how an evolving central nervous system responds to different stimuli."

The findings are important to understanding and preventing the recurrence of the H1N1 influenza virus that caused the 1918 pandemic, and to protecting against future flu virus strains in the future, including the H5N1 avian flu virus, the researchers said.

The 1918-1919 pandemic, the most deadly flu outbreak in modern history, killed 30 million or more people worldwide. Scientists are afraid that a new flu virus strain would cause a similar disaster.

"A key to containing pandemic flu viruses is to understand their vulnerabilities and determine whether they can evade immune recognition," said Gary Nabel, director of the Vaccine Research Center at U.S. National Institute of Allergy and Infectious Diseases who led the study.

"What we learn about the H1N1 virus that caused the 1918 pandemic is pertinent to other pandemic viruses and to the development of effective and universal vaccines."

Using the genetic sequence information for the 1918 flu virus, the researchers created plasmids, small strands of DNA designed to express specific characteristics, carrying genes for the virus' hemagglutinin (HA) protein, the surface protein found in all flu viruses that allows the virus to stick to a cell and cause infection.

They created two types of plasmids: one to reflect the HA found in the original 1918 flu virus; the other an altered HA protein designed to weaken the virus.

Mice were then injected with a DNA vaccine containing both types of plasmids to determine whether they would generate immune responses to the 1918 virus.

The researchers found significant responses both in terms of production of T-cells, the white blood cells critical in the immune system's battle against invading viruses, as well as the production of neutralizing antibodies.

All of the 10 immunized mice survived when they were exposed to reconstructed 1918 virus 14 days later, and eight of the 10 mice that received antibodies from the immunized mice also survived the challenge, the researchers reported.

To evaluate the vaccine's antibody-inducing capabilities while minimizing exposure of lab personnel to the deadly virus, the researchers also created artificial viruses, or pseudoviruses, featuring the HA of the 1918 flu virus but stripped of the ability to cause infection.

The pseudoviruses were then incubated with antibody-containing blood samples from the mice immunized with the DNA vaccine and those that were not. The researchers found that the antibodies from the immunized mice neutralized the pseudoviruses while the blood samples from the mice that were not immunized had no effect.

This method was also effective in identifying neutralizing antibodies to the H5N1 avian flu virus and could be used to screen for monoclonal antibodies that may be used as an antiviral treatment, according to Nabel.

Lead author Kent Hatch from the university's Department of Integrative Biology said clinicians could use this as a tool to help diagnose such disorders as anorexia or bulimia because many sufferers lied or did not recognize their problems.

Current methods used to diagnose and monitor patients suffering from eating disorders relied heavily on questionnaires and interviews.

"Their self-evaluation is very impaired," said Jennifer Tolman, clinical director at Avalon Hills, a treatment facility in Cache County, Utah of the United States.

"We had a girl who was five feet and 10 inches tall and weighed 98 pounds and she wasn't even sure she had an eating disorder, although she could recognize it in others," Tolman said.

Hair grows by adding new proteins to the base of the strand, and pushing the strand up out of the hair follicle. The make-up of these proteins will be influenced by the nutritional state of the person at that moment. This nutritional state is in turn subtly affected by eating patterns associated with eating disorders. Because hair grows all the time, each strand consequently becomes a chemical diary, recording an individual's day-by-day nutrition, the researchers said.

The findings backed those of previous, less rigorous studies, according to Stanford.

Most disturbing was the discovery that some people hid their Internet surfing, or went online to cure foul moods in ways that mirrored alcoholics using booze, according to the study's lead author, Elias Aboujaoude.

"In a sense, they're using the Internet to self-medicate," Aboujaoude said. "And obviously something is wrong when people go out of their way to hide their Internet activity."

According to preliminary research, the typical Internet addict was a single, college-educated, white male in his 30s, who spends approximately 30 hours a week on non-essential computer use.