According to background information in the article, "Neuroimaging studies are beginning to clarify the relationship between the brain's cortical and subcortical activity in regulating the emotional and cognitive functions of behavior." "A temperamental disposition toward the avoidance of novel and uncertain situations together with a set of behaviors that indicate shyness and discomfort in social interactions are comprehensively named childhood shyness, or behavioral inhibition (BI). Children with high indexes of shyness-BI are at a heightened risk of developing anxiety disorders, in particular social phobia."

Marco Battaglia, M.D., from the Istituto Scientifico San Raffaele, Milan, Italy, and colleagues analyzed the responses of 49 third- and fourth-grade schoolchildren (characterized as shy) to different emotional facial expressions. The researchers showed the study participants pictures of boys and girls with facial expressions that depicted joy, neutrality, and anger. The study participants were assessed through questionnaires and responses were also recorded with electrodes measuring brain wave activity.

The researchers found that the shyness-BI index and the presence of particular forms of the serotonin transporter promoter gene predicted smaller responses to overtly hostile and neutral facial expressions in certain regions of the brain. The researchers suggest that their findings indicate diminished brain involvement and partially impaired reading in response to some facial expressions. "Shy children have been shown to provide relatively distinct physiologic responses in a variety of contexts," the researchers write. "These data suggest that a biased pattern of processing emotional information of social relevance can be recognized and characterized early in life."

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Many cases of prostate cancer depend on androgens like testosterone for tumor growth and cancer cell proliferation, said Dr. Knudsen, the study's senior author. A common treatment for prostate cancer includes limiting testosterone synthesis. Patients with mutated androgen receptors may not respond to this therapy and according to this new study, exposure to BPA among these patients could potentially put them at higher risk for increased cancer cell growth.

"The results we see in cell culture in response to BPA are ready to be moved to appropriate animal models next," said Dr. Knudsen. The effect of the environmental non-steroidal BPA on human prostate cancer tumor implants in laboratory animal models will shed additional light on whether the synthetic pseudo-estrogen encourages tumor growth in whole animal systems.

"We'll know more about the 'hormone sensitizing' ability of BPA in prostate cancer cells from studies on animals. It is also important to note that our study demonstrates that the actual dose of BPA exposure may change the biological response," Dr. Knudsen said.

The safety of BPA has been under intense debate for several years, with some arguing that exposure to the chemical among humans is safe, with others contending that it may promote the growth of human tumor cells and alter the growth and development of animals.

Also participating in the study were Yelena Wetherill, Ph.D., Nicola Fisher, B.S., and Ann Staubach, B.S., all with the University of Cincinnati; Mark Danielsen, Ph.D., Georgetown University, Washington, D.C.; and Ralph De Vere White, M.D., the University of California, Davis.

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