Accomplishments

• Helped pediatricians and geneticists investigate a mental retardation syndrome known as "18Q minus." The disorder is one of the most common chromosomal deletions among children. It causes mental retardation or developmental delay.

  Imaging center specialists helped adapt magnetic resonance imaging (MRI) equipment for research by Charles T. Gay, MD, an assistant professor and pediatric neurologist. Brain images from "18Q minus" patients revealed abnormalities in their myelin, a fatty sheath that acts as an insulator for the brain's wiring. Myelin is laid down on the brain's circuitry starting at birth through a person's 20s, promoting brain maturation.

  Comparing brain scans to each individual's molecular makeup, Health Science Center geneticists were able to show that every "18Q minus" patient with abnormal myelin lacked a second copy of a gene involved in building myelin. Normal subjects have two copies.

  The discovery came in the laboratory of Robin J. Leach, PhD, assistant professor of cellular and structural biology, and involved Barbara R. Dupont, PhD, an assistant instructor, and doctoral student Jannine D. Cody, whose daughter has the syndrome. The geneticists and pediatricians have established further information that links growth hormone insufficiency to "18Q minus." Tests of growth hormone therapy as a potential treatment now are under way.

• Started the first PET, or positron-emission tomography, imaging of the brain function of Vietnam veterans with post-traumatic stress disorder. The project is for the Department of Veterans Affairs. Related studies of the disorder have identified bodily responses to the accompanying anxiety, such as elevated heart rates, but brain function has not been examined, said Stephen K. Brannan, MD, who heads the project. Dr. Brannan, an assistant professor of psychiatry, also is a psychiatrist at Audie L. Murphy Memorial Veterans Hospital in San Antonio. In the new study, which began in March, veterans with recurring episodes of anxiety listen to a script that describes their worst wartime experiences. The script is designed to trigger anxiety so that PET imagers can look in the brain for the origin of the disorder.

• Begun to prove that PET imaging can effectively detect reversible brain injury. Assisting Lt. Col. Stephen A. McGuire, MD, from Wilford Hall U.S. Air Force Medical Center in San Antonio, the RIC's researchers are performing PET and MRI scans of patients with closed-head injuries. Wilford Hall is one of seven U.S. sites working on the Defense Department project. The RIC is the only site performing PET scans.

• Joined in a rare study of schizophrenics who are having their first episode of the illness and hence are not taking anti-psychotic medication. Most PET studies involve patients who already are taking the medications, which experts say affect the accuracy of brain images. In a study supported by the Defense Department and directed by Maj. Richard M. Pico, MD, PhD, a Wilford Hall neuropsychiatrist, the RIC performs PET and MRI scans on Air Force recruits diagnosed as schizophrenic during their basic training at Lackland Air Force Base in San Antonio. About 20 recruits a year are diagnosed and scanned. Schizophrenia typically manifests itself in young adult life and under times of stress. Military basic training is a "treadmill for psychosis," Dr. Pico said. The project's goal is to advance the understanding of schizophrenia.