HELP FOR
Brain Injuries A nanoparticle developed at Rice University and tested in collaboration with Baylor College of Medicine (BCM) may bring great benefits to the emergency treatment of brain-injury victims, even those with mild injuries. Combined polyethylene glycol-hydrophilic carbon clusters (PEG-HCC), already being tested to enhance cancer treatment, are also adept antioxidants. In animal studies, injections of PEGHCC during initial treatment after an injury helped restore balance to the brain’s vascular system. A PEG-HCC infusion that quickly stabilizes blood flow in the brain would be a significant advance for emergency-care workers and battlefield medics, said Rice chemist and co-author James Tour. “This might be a first line of defense against reactive oxygen species (ROS) that are always overstimulated during a medical trauma, whether that be to an accident victim or an injured soldier,” said Tour, Rice’s T.T. and W.F. Chao Professor of Chemistry as well as a professor of mechanical engineering and materials science and of computer science. “They’re certainly exacerbated when there’s trauma with massive blood loss.” In a traumatic brain injury, cells release an excessive amount of an ROS known as superoxide into the blood. Superoxides are toxic free radicals, molecules with one unpaired electron, that the immune system normally uses to kill invading microorganisms. “There are many facets of brain injury that ultimately determine how much damage there will be,” said Thomas Kent, the paper’s co-author, a BCM professor of neurology and chief of neurology at the Michael E. DeBakey Veterans Affairs Medical Center in Houston. “One is the initial injury, and that’s pretty much done in minutes. But a number of things that happen later often make things worse, and that’s when we can intervene.” In tests, the researchers found PEG-HCC nanoparticles immediately and completely quenched superoxide activity and allowed the autoregulatory system to quickly regain its balance. “This is an occasion where a nano-sized package is doing something that no small drug or protein could do, underscoring the efficacy of active nano-based drugs,” said Tour. “This is the most remarkably effective thing I’ve ever seen,” Kent said. The research was funded by the Department of Defense’s Mission Connect Mild Traumatic Brain Injury Translational Research Consortium, the National Science Foundation, the National Institutes of Health, and the National Heart, Lung and Blood Institute.
Predatory Bacteria Scientists ID a simple formula that allows bacteria to engulf food in waves. Move forward. High-five your neighbor. Turn around. Repeat. That’s the winning formula of one of the world’s smallest predators, the soil bacteria Myxococcus xanthus. A new study by scientists at Rice University and the University of Texas Health Science Center at Houston (UTHealth) Medical School shows how M. xanthus uses the formula to spread, engulf and devour other bacteria. Researchers found that simple motions of individual bacteria are amplified within colonies of M. xanthus to form millions-strong waves moving outward in unison. The findings answer long-standing questions about how the waves form and the competitive edge they provide M. xanthus. “When the cells at the edge of the colony are moving outward, they are unlikely to encounter another M. xanthus cell, so they keep moving forward,” said lead author Oleg Igoshin, assistant professor of bioengineering at Rice. “When they are traveling the other way, back toward the rest of the colony, they are likely to encounter other cells of their kind, and when they pass beside one of these and touch, they get the signal to turn around.” M. xanthus is an oft-studied model organism in biology, Igoshin said. As a computational biologist, Igoshin specializes in creating mathematical models that accurately describe the behavior of living systems. Such models are useful for understanding the cellular and even genetic basis of emergent phenomena. The research was supported by the National Science Foundation (NSF). The computer modeling was performed on three NSF-funded Rice supercomputers — STIC, SUG@R and DAVinCI — that are jointly managed and operated by Rice’s Ken Kennedy Institute for Information Technology and Rice’s Information Technology office. —Jade Boyd
—Mike Williams
Rice Magazine
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No. 15
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2013
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