Research Briefs: Rakez Kayed, Bridget Hawkins, Sapna Kaul, Alex Bukreyev and Ashok Chopra

Feb 18, 2016, 10:17 AM by Donna Ramirez
Rakez Kayed, PhD, associate professor of Neurology, and Bridget Hawkins, PhD assistant professor of Anesthesiology, have filled an important gap in understanding the link between traumatic brain injury and neurodegenerative disorders such as Alzheimer’s disease. Previously, UTMB researchers found a toxic form of tau protein that increases after a traumatic brain injury and may contribute to development of chronic traumatic encephalopathy, a condition experienced by many professional athletes and military personnel. What remained a mystery was if this protein could cause dementia symptoms. The researchers isolated this protein from animals that had experienced a TBI and then injected it into another group of animals to see if they would develop impairments. The animals developed the same type of mental impairments caused by Alzheimer’s disease. These findings provide direct evidence that this form of toxic tau induces many TBI symptoms and may be responsible for the spread of impairments throughout the brain. These new findings can be found in the Journal of Neurotrauma.

Sapna Kaul, PhD, assistant professor of Preventive Medicine and Community Health, found that more than half of primary care providers admit to providing unnecessary referrals to a specialist because patients request it. Many physicians also said they yielded to patient requests for brand-name drug prescriptions when cheaper generics were available. Thirty percent of U.S. health care expenses each year are thought to be unnecessary. Physicians are increasingly expected to consider the costs of their treatment plans on the health care system when making medical decisions. However, little is known about how physicians balance cost-saving expectations in the face of patient requests. In this study, researchers used data from a nationally representative survey of 840 primary care physicians in Family Practice, Internal Medicine and Pediatrics. In response to patient requests, 52 percent of the surveyed physicians reported making what they considered unnecessary referrals for a specialist and 39 percent prescribed brand-name drugs despite generic alternatives. The study appears in the American Journal of Managed Care.

Alex Bukreyev, PhD, professor of Pathology, has learned that antibodies in the blood of people who have survived a strain of the Ebola virus can kill various types of Ebola. The findings are significant because it helps researchers further understand the immune response to a virus such as Ebola. In the study, researchers used the blood of seven people who survived Ebola Bundibugyo virus infection during the 2007 outbreak in Uganda to isolate a large number of B cells that produce antibodies, which are the small protein molecules capable of inactivating the virus. A portion of the isolated antibodies effectively protected mice and guinea pigs against a lethal Ebola Zaire infection. Bukreyev believes the results provide a roadmap to developing a single antibody-based treatment effective against not only infections caused by Ebola Zaire virus, but also those caused by related filoviruses. The study is currently available in the journal Cell.

Ashok Chopra, PhD, professor of Microbiology and Immunology, and colleagues have discovered different strains of deadly flesh-eating bacteria working together to spread infection. The findings give a better understanding of the role of the toxins they produce and could change how the illness and other diseases are treated. The bacteria Aeromonas hydrophila has been increasingly acknowledged as being responsible for necrotizing fasciitis, a rapidly-progressing skin and muscle tissue infection. The researchers studied a human case of necrotizing fasciitis and identified four strains of the bacteria that caused the infection. Three of the strains were closely related, but one was different from the others. They found that the three similar strains produced a toxin called ExoA that is responsible for breaking down muscle tissue, allowing the distinct strain to move to other parts of the body. This discovery could alter the way medical researchers think about this and other bacterial diseases that are commonly thought to be caused by a single species of bacterium. The study is published in the Proceedings of the National Academy of Sciences.

Compiled from press releases written by Donna Ramirez. Find out more at www.utmb.edu/newsroom.