Posts Tagged ‘University of Maryland’


Over the past 15 years, more than 330,000 US soldiers have suffered a traumatic brain injury. Many were evacuated by air for further treatment. A new study has found evidence that such air evacuations may pose a significant added risk, potentially causing more damage to already injured brains.

Over the past 15 years, more than 330,000 U.S. soldiers have suffered a traumatic brain injury (TBI). It is one of the leading causes of death and disability connected to the country’s recent conflicts in Afghanistan and Iraq. Many of these patients were evacuated by air from these countries to Europe and the U.S. for further treatment. In general, these patients were flown quickly to hospitals outside the battle zone, where more extensive treatment was available.

But now a new study by researchers at the University of Maryland School of Medicine has found evidence that such air evacuations may pose a significant added risk, potentially causing more damage to already injured brains. The study is the first to suggest that air evacuation may be hazardous for TBI patients. The study was published in the Journal of Neurotrauma.

“This research shows that exposure to reduced barometric pressure, as occurs on military planes used for evacuation, substantially worsens neurological function and increases brain cell loss after experimental TBI — even when oxygen levels are kept in the normal range. It suggests that we need to carefully re-evaluate the cost-benefit of air transport in the first days after injury,” said lead researcher Alan Faden, MD, the David S. Brown Professor in Trauma in the Departments of Anesthesiology, Anatomy & Neurobiology, Neurology, and Neurosurgery, and director, Shock, Trauma and Anesthesiology Research Center (STAR) as well as the National Study Center for Trauma and Emergency Medical Services.

About a quarter of all injured soldiers evacuated from Afghanistan and Iraq have suffered head injuries.

Faden and his colleagues tested rats that were subjected to TBI, using a model that simulates key aspects of human brain injury. Animals were exposed to six hours of lowered air pressure, known as hypobaria, at levels that simulated conditions during transport; control animals were exposed to normal pressure. All the animals received extra oxygen to restore normal oxygen concentrations in the blood. In another study, animals received oxygen, either as in the first study or at much higher 100 percent concentration, which is often used during military air evacuations. On its own, low air pressure worsened long-term cognitive function and increased chronic brain inflammation and brain tissue loss. Pure oxygen further worsened outcomes.

Faden and his colleagues believe the findings raise concerns about the increased use of relatively early air evacuation, and suggest that this potential risk should be weighed against the benefits of improved care after evacuation. It may be necessary, he says, to change the current policy for TBI patients and delaying air evacuation in many cases.

In an accompanying editorial, Patrick Kochanek, MD, a leading expert on TBI and trauma care at the University of Pittsburgh, called the findings “highly novel and eye-opening,” and said that they could have “impactful clinical relevance for the field of traumatic brain injury in both military and civilian applications.”

Faden and colleagues believe that one of the mechanisms by which hypobaria worsens TBI is by increasing persistent brain inflammation after injury. They are currently examining how this process occurs and have tested treatments that can reduce the risks of air evacuation. Early results are promising. Scientists suspect that breathing pure oxygen could worsen TBI by increasing production of dangerous free radicals in the brain. After brain injury, these free radicals flood the site of injury, and pure oxygen may further boost these levels. Several recent studies from trauma centers, including from the R Adams Cowley Shock Trauma Center at the University of Maryland Medical Center, have found evidence that using 100 percent oxygen in trauma patients may be counterproductive.

Journal Reference:

Jacob W Skovira, Shruti V Kabadi, Junfang Wu, Zaorui Zhao, Joseph DuBose, Robert E Rosenthal, Gary Fiskum, Alan I Faden. Simulated Aeromedical Evacuation Exacerbates Experimental Brain Injury. Journal of Neurotrauma, 2015; DOI: 10.1089/neu.2015.4189

http://www.sciencedaily.com/releases/2015/11/151130110013.htm

A new study by researchers at University of Maryland School of Medicine has identified promising compounds that could successfully treat depression in less than 24 hours while minimizing side effects. Although they have not yet been tested in people, the compounds could offer significant advantages over current antidepressant medications.

The research, led by Scott Thompson, PhD, Professor and Chair of the Department of Physiology at the University of Maryland School of Medicine (UM SOM), was published this month in the journal Neuropsychopharmacology.

“Our results open up a whole new class of potential antidepressant medications,” said Dr. Thompson. “We have evidence that these compounds can relieve the devastating symptoms of depression in less than one day, and can do so in a way that limits some of the key disadvantages of current approaches.”

Currently, most people with depression take medications that increase levels of the neurochemical serotonin in the brain. The most common of these drugs, such as Prozac and Lexapro, are selective serotonin reuptake inhibitors, or SSRIs. Unfortunately, SSRIs are effective in only a third of patients with depression. In addition, even when these drugs work, they typically take between three and eight weeks to relieve symptoms. As a result, patients often suffer for months before finding a medicine that makes them feel better. This is not only emotionally excruciating; in the case of patients who are suicidal, it can be deadly. Better treatments for depression are clearly needed.

Dr. Thompson and his team focused on another neurotransmitter besides serotonin, an inhibitory compound called GABA. Brain activity is determined by a balance of opposing excitatory and inhibitory communication between brain cells. Dr. Thompson and his team argue that in depression, excitatory messages in some brain regions are not strong enough. Because there is no safe way to directly strengthen excitatory communication, they examined a class of compounds that reduce the inhibitory messages sent via GABA. They predicted that these compounds would restore excitatory strength. These compounds, called GABA-NAMs, minimize unwanted side effects because they are precise: they work only in the parts of the brain that are essential for mood.

The researchers tested the compounds in rats that were subjected to chronic mild stress that caused the animals to act in ways that resemble human depression. Giving stressed rats GABA-NAMs successfully reversed experimental signs of a key symptom of depression, anhedonia, or the inability to feel pleasure. Remarkably, the beneficial effects of the compounds appeared within 24 hours – much faster than the multiple weeks needed for SSRIs to produce the same effects.

“These compounds produced the most dramatic effects in animal studies that we could have hoped for,” Dr. Thompson said. “It will now be tremendously exciting to find out whether they produce similar effects in depressed patients. If these compounds can quickly provide relief of the symptoms of human depression, such as suicidal thinking, it could revolutionize the way patients are treated.”

In tests on the rats’ brains, the researchers found that the compounds rapidly increased the strength of excitatory communication in regions that were weakened by stress and are thought to be weakened in human depression. No effects of the compound were detected in unstressed animals, raising hopes that they will not produce side effects in human patients.

“This work underscores the importance of basic research to our clinical future,” said Dean E. Albert Reece, MD, PhD, MBA, who is also the vice president for Medical Affairs, University of Maryland, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean of the School of Medicine. “Dr. Thompson’s work lays the crucial groundwork to transform the treatment of depression and reduce the tragic loss of lives to suicide.”

http://www.news-medical.net/news/20150714/New-study-identifies-potential-antidepressant-medications-with-few-side-effects.aspx