Anti-rejection drug can prevent inflammation of pancreas

Exposure to an X-ray dye during a common procedure to treat gallstones causes some patients to develop inflammation of the pancreas, according to researchers at the School of Medicine and Children’s Hospital. In a study published online in Gastroenterology, the team noted that a single dose of FK506, an anti-rejection drug typically used after organ transplantation, might be able to prevent the complication.

During the endoscopic retrograde cholangiopancreatography (ERCP) procedure, doctors insert a fiber-optic endoscope through the mouth, esophagus, stomach and duodenum to access the bile ducts, where a gallstone might be lodged. The X-ray dye, also known as radiocontrast, is infused through a catheter so doctors can visualize the bile ducts and anything obstructing them, explained senior author and principal investigator Sohail Z. Husain, pediatrics faculty member.

Said Husain: “Thousands of ERCP procedures are performed every year, particularly for the removal of gallstones. But after the procedure, a fair number of patients develop acute pancreatitis, which is an exquisitely painful, life-threatening inflammation of the pancreas. Our findings provide the first explanation for why this complication occurs, namely through the signals that FK506 can block.”

The research team examined what happened to pancreatic cells in mice after they received infusions of two common radiocontrast agents. They found the agents elevated cellular calcium levels, in turn activating proteins, particularly calcineurin, involved in inflammatory pathways that cause tissue injury. Similar results were observed in experiments with human pancreatic cells. Also, mice that were genetically modified to lack calcineurin failed to develop pancreatitis after radiocontrast exposure.

Mice that were given the anti-rejection drug FK506, which is an inhibitor of calcineurin, before and after infusion of the X-ray dye also were protected from pancreatitis.

“In the future, we will test other radiocontrast agents to see if they, too, affect the same inflammatory pathways,” Husain said. “This study already sets the stage for a clinical trial to test whether calcineurin inhibitors alone or in combination with other drugs can prevent post-ERCP pancreatitis.”

The team included Pitt faculty members Shunqian Jin, Abrahim I. Orabi, Tianming Le, Tanveer A. Javed, Swati Sah and John F. Eisses, with researchers from Allegheny General Hospital and the University of Cincinnati.

The project was funded by the National Institutes of Health (NIH).

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Mosquito-borne viruses subject of $4M in grants

Scientists at the Center for Vaccine Research (CVR) recently received nearly $4 million through five federal grants to study a group of related mosquito-borne viruses. The ultimate goal is to develop vaccines and therapies against the deadly diseases.

The research will be conducted in the Regional Biocontainment Laboratory at Pitt, a high-security facility that allows scientists to safely contain and examine potentially dangerous pathogens.

William Klimstra is principal investigator on three of the grants and about half the funding. Kate D. Ryman is principal investigator on the other two grants. Both are faculty members in the School of Medicine’s microbiology and molecular genetics department.

Said Klimstra: “While the number of people who get these diseases is relatively small, the severity of the diseases and their potential emergence in larger populations or for use as bioweapons drive the necessity for development of countermeasures.”

Two of Klimstra’s grants, both from NIH and totaling $847,000, focus on Eastern equine encephalitis virus (EEEV), a rare disease that is found primarily in the Atlantic and Gulf states and kills about half of the people it infects. One of the grants will be used to examine a specific part of the genetic code of the virus that is largely responsible for the severity of human disease, while the other will go toward developing a novel, live-attenuated vaccine against the virus.

Klimstra’s other grant, which is a collaboration with colleagues at Washington University in St. Louis and Oregon Health and Sciences University, will provide $1.2 million to Klimstra and CVR colleagues from the Department of Defense (DOD). This will be used to develop a novel, inactivated vaccine against three strains of alphavirus, a group that comprises about 30 different viruses mainly transmitted by mosquitoes — including EEEV and Venezuelan (VEEV) and Western (WEEV) equine encephalitis viruses, which cause periodic outbreaks in the Americas.

Ryman received $1 million from DOD to study how these three encephalitic alphaviruses and another mosquito-borne virus, Rift Valley Fever virus (RVFV), enter the brain. The RVFV component is led by Amy Hartman, infectious diseases and microbiology faculty member in the Graduate School of Public Health. The goal is to develop ways to limit brain entry by the virus and identify biological markers of disease severity to use as a measure of the effects of the vaccines and therapeutics. This grant also involves studies with collaborators at the University of Wisconsin.

Ryman also received $725,000 from DOD in collaboration with investigators at the Naval Medical Research Center to raise anti-VEEV antibodies by immunizing cows that have been genetically altered to produce human antibodies. These antibodies will be assessed for their potential use in protection against alphavirus diseases, similar to convalescent sera, which is derived from the blood of people whose immune systems successfully fought off an infection.

Several of the grants have option periods that, given successful results in initial studies, will result in an additional $3 million in funding.

Said Ryman: “The technologies used in these studies and the systematic manner in which vaccines and therapeutics for the alphaviruses are being developed are novel and, given positive results, these approaches can be readily applied to other emerging infectious diseases.”
Pitt faculty members Simon Watkins and Douglas Reed are involved in some of these studies.

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Pitt leads $1.5M trial of antimicrobial resistance

The School of Medicine will be leading a $1.5 million national trial to examine methods to reduce unnecessary use of antibiotics in post-acute and long-term care (PA/LTC) facilities.

The three-year study, funded by the Department of Health and Human Services’ Agency for Healthcare Research and Quality (AHRQ), will investigate guidelines and tools to help PA/LTC facilities better manage urinary tract infections (UTIs), which often are misdiagnosed and incorrectly treated.

Said David A. Nace, medicine department faculty member, director of long-term care and flu programs in the Division of Geriatric Medicine, and primary investigator on the AHRQ grant: “Antimicrobial resistance is a hot-button issue in health care nationally and internationally — and improper overutilization of antibiotics is the single largest culprit. It is critically important that we find ways to cut unnecessary use of antibiotics.”

The World Health Organization and the White House, among others, recently made announcements declaring efforts to address antimicrobial resistance top priorities. JAMA Internal Medicine published an article recently reporting that antibiotic use is highly variable across nursing homes, exposing residents to an increased risk of antibiotic-related harms and indicating a need to improve antibiotic stewardship in PA/LTC facilities.

The leading reason for antibiotic use at PA/LTC facilities is to treat a suspected UTI. Antibiotics often are started before a correct diagnosis is made. However, as many as two-thirds of those suspected cases turn out not to be UTIs, and the patients don’t benefit from — and could be harmed by— the antibiotics.

When used incorrectly, antibiotics can kill good bacteria and allow harmful, drug-resistant bacteria to flourish. Antibiotics also can cause allergic reactions or side effects and are the leading cause of adverse drug reactions in long-term care facilities.

Nace, also chief medical officer for UPMC Senior Communities, and his co-investigators at AMDA-The Society for Post-Acute and Long-Term Care Medicine and the University of Wisconsin, are looking at existing guidance and research on UTIs to develop comprehensive guidelines and tools geared toward easy implementation at PA/LTC facilities.

In 2016, the team will enroll 40 PA/LTC facilities from Pennsylvania, Texas, North Carolina and Wisconsin in the trial. Half will receive the guidelines, as well as ongoing mentoring and education, while the other half will operate as normal.

For a year, the team will collect data on the number of UTIs before and after the trial, the rate of appropriate and inappropriate treatment, and adverse outcomes. Once the trial concludes, all the facilities will be given the guidelines, tools, mentoring and education.

“There’s a lot of pressure across both agriculture and medicine to rein in use of antibiotics,” said Nace. “We are very quickly running out of antibiotics to do the job for us, and the problem is only going to grow worse. New antibiotics are not being created and licensed fast enough to keep pace with bacterium’s ability to develop drug resistance. Efforts like ours to become better stewards of existing antibiotics are among the few solutions left at our disposal.”

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Different immune response found in severe asthma

The immune response that occurs in patients with severe asthma is markedly different than what occurs in milder forms of the lung condition, according to researchers from the School of Medicine. Those unique features could point the way to new treatments, they said in an article published online in the Journal of Clinical Investigation.

People with severe asthma, in which the airways become inflamed and constrict to impair breathing, do not get better even with high doses of corticosteroids, the mainstay of treatment for typical asthma, explained Anuradha Ray, medicine faculty member.

Said Ray: “About 10 percent of asthma patients have a severe form of the disease, but they account for up to half of asthma costs in the U.S. and Europe. That’s because these patients frequently need to go to the emergency room or be hospitalized when they have an acute asthma episode.”

For the study, conducted as part of the doctoral thesis of Mahesh Raundhal, a graduate student in the laboratory of Prabir Ray, a faculty member in medicine and co-senior author, the research team examined lung cell samples obtained from patients also participating in the severe asthma research program (SARP), which is sponsored by the National Heart, Lung and Blood Institute of NIH to improve the understanding of severe asthma. Sally Wenzel, medicine faculty member and director of the University of Pittsburgh Asthma Institute of UPMC, is the Pitt SARP principal investigator.

Researchers observed that the immune cells, called CD4 T-cells, in the airways of severe asthmatics secreted different inflammatory proteins than those in mild disease, particularly interferon gamma. The analysis of human samples helped them to develop a mouse model of the disease by introducing an allergen and a bacterial product to induce an immune profile and airway hyper-reactivity that were poorly controlled by corticosteroids, comparable to human severe asthma patients.

When they subjected mice that lacked the interferon gamma gene to the severe asthma model, they found that the mice could not be induced to develop severe asthma. Using computer modeling to identify links between interferon gamma and asthma-associated genes, they learned that as interferon gamma levels rose, the levels of a protein called secretory leukocyte protease inhibitor (SLPI) dropped.

In follow-up experiments, the team found that boosting SLPI levels reduced airway hyper-reactivity in the animal model.

“We’d like to better understand why severe asthma occurs in most people right from the start,” Anuradha Ray said. “We also want to find agents that can raise SLPI levels for clinical use.”

In a new project that began this month, she and Wenzel will continue studying the immune response and genetic roots of severe asthma in 120 patients and in animal models through a five-year, $8 million grant from the National Institute of Allergy and Infectious Diseases, also part of the NIH.

Other Pitt project leaders were Timothy B. Oriss and Jay Kolls, who co-authored the paper.  University faculty Fernando Holguin, Douglas Landsittel and Donald DeFranco also were part of the team.

NIH and the Cystic Fibrosis Foundation research development program funded the project.

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Why does teen brain value rewards over risks?

Why does the promise of a reward — basically any kind of fun — cause teens to throw caution to the wind?

Contemporary scientific theory suggests that teenagers are risk takers because they crave the feel-good rush of dopamine, a neurotransmitter that helps control the brain’s reward and pleasure centers. That theory, however, has been based on a long line of studies on the adult brain.

Bita Moghaddam, neuroscience faculty member in the Dietrich School of Arts and Sciences, and her research group have taken a look at the teen brain — the teen rat’s brain, specifically — and found that scientists’ presumptions may be off base.

Said Moghaddam: “The adolescent brain doesn’t work the way we think it does. We have a set of predictions about it that keep proving to be wrong, that they seek pleasure because dopamine is more active. This study shows that may not be the case.”

She recently published a paper in Biological Psychiatry showing that when adolescents are faced with the prospect of a reward, their dopamine neurons are actually activated less than in adults.

This may seem counterintuitive, but, to Moghaddam, it makes perfect sense. The study shows that adult rats get a small dopamine rush from simply anticipating a reward, while adolescent rats don’t get the same level of dopamine-based satisfaction. In humans, this is reflected in teenagers needing to do something, even a risky something, to get that dopamine rush. Anticipation isn’t enough for teens.

“The study also shows that preactivation [of the dopamine neurons] — pausing for a millisecond or two before doing something — is missing in the adolescents,” Moghaddam adds. “So they actually go into action and start seeking reward without that sort of pause that the adult brain may have.”

Moghaddam’s study also sheds some light on why adolescents seem prone to doing the same thing again and again even if it ends badly every time.

“When adults learn that there will be no reward, their dopamine cells stop responding. But adolescent dopamine cells retain memories of past rewards,” she says.

Evolutionarily speaking, this may have been a useful survival trait. “At that age, ‘This did something good, and maybe it will again,’ is very important,” Moghaddam says. “Those years were very critical for [ancient] humans, an important time to secure food and to find a mate, to be proactive. ‘Maybe I can go back to find food where I found it once even though it wasn’t there the last time.’ That memory is there and helps motivate a person to look for a reward where they found it before.” But that property of adolescents’ brains also can make them vulnerable to drug seeking and disadvantageous risk-taking, Moghaddam says.

Other authors were Pitt postdoctoral associates Yunbok Kim and Nicholas Simon and postdoctoral fellow Jesse Wood.

The National Institute of Mental Health funded the research.

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Computer simulation of pressure sores developed

Researchers at the School of Medicine have devised a computational model that could enhance understanding, diagnosis and treatment of pressure ulcers related to spinal cord injury.

In a report published online in PLOS Computational Biology, the team also described results of virtual clinical trials that showed that for effective treatment of the lesions, anti-inflammatory measures had to be applied well before the earliest clinical signs of ulcer formation.

Pressure ulcers affect more than 2.5 million Americans annually and patients who have spinal cord injuries that impair movement are more vulnerable to developing them, said senior investigator Yoram Vodovotz, surgery faculty member and director of the Center for Inflammation and Regenerative Modeling at the school.

Said Vodovotz: “These lesions are thought to develop because immobility disrupts adequate oxygenation of tissues where the patient is lying down, followed by sudden resumption of blood flow when the patient is turned in bed to change positions. This is accompanied by an inflammatory response that sometimes leads to further tissue damage and breakdown of the skin.”

Added co-author Gwendolyn A. Sowa, physical medicine and rehabilitation faculty member in the school: “Pressure ulcers are an unfortunately common complication after spinal cord injury and cause discomfort and functional limitations. Improving the individual diagnosis and treatment of pressure ulcers has the potential to reduce the cost of care and improve quality of life for persons living with spinal cord injury.”

To address the complexity of the biologic pathways that create and respond to pressure sore development, the researchers designed a computational, or in silico, model of the process based on serial photographs of developing ulcers from spinal cord-injured patients enrolled in studies at the Rehabilitation Engineering Research Center on Spinal Cord Injury. Photos were taken when the ulcer was initially diagnosed, three times per week in the acute stage and once a week as it resolved.

Researchers then validated the model, finding that if they started with a single small round area over a virtual bony protuberance and altered factors such as inflammatory mediators and tissue oxygenation, they could recreate a variety of irregularly shaped ulcers that mimic what is seen in reality.

They also conducted two virtual trials of potential interventions, finding that anti-inflammatory interventions could not prevent ulcers unless applied very early in their development.

In the future, perhaps a nurse or caregiver could simply send in a photo of a patient’s reddened skin to a doctor using the model to find out whether it was likely to develop into a pressure sore for quick and aggressive treatment to keep it from getting far worse, Vodovotz speculated.

“Computational models like this one might one day be able to predict the clinical course of a disease or injury, as well as make it possible to do less expensive testing of experimental drugs and interventions to see whether they are worth pursuing with human trials,” he said.

The team included Pitt’s Cordelia Ziraldo, Alexey Solovyev, Ana Allegretti, Shilpa Krishnan, David Brienza and Qi Mi, plus researchers from the University of Chicago and the Louis Stokes Cleveland Veterans Affairs Medical Center.

The project was funded by the U.S. Department of Education; NIH’s National Institute on Disability and Rehabilitation, and IBM.

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Hybrid has potential for “materials that compute”

Moving closer to the possibility of “materials that compute” and wearing your computer on your sleeve, researchers at the Swanson School of Engineering have designed a responsive hybrid material that is fueled by an oscillatory chemical reaction and can perform computations based on changes in the environment or movement, and potentially even respond to human vital signs. The material system is sufficiently small and flexible that it could be integrated into a fabric or introduced as an inset into a shoe.

Anna C. Balazs, Distinguished Professor of Chemical and Petroleum Engineering, and Steven P. Levitan, John A. Jurenko Professor of Electrical and Computer Engineering, integrated models for self-oscillating polymer gels and piezoelectric micro-electric-mechanical systems to devise a new reactive material system capable of performing computations without external energy inputs, amplification or computer mediation.

Their research appeared in Scientific Reports, published by Nature. The studies combine Balazs’ research in Belousov-Zhabotinsky (BZ) gels, a substance that oscillates in the absence of external stimuli, and Levitan’s expertise in computational modeling and oscillator-based computing systems.

By working with Victor V. Yashin, chemical and petroleum engineering faculty member and lead author on the paper, the researchers developed design rules for creating a hybrid “BZ-PZ” material.

Said Balazs: “The BZ reaction drives the periodic oxidation and reduction of a metal catalyst that is anchored to the gel; this, in turn, makes the gel swell and shrink. We put a thin piezoelectric (PZ) cantilever over the gel so that when the PZ is bent by the oscillating gel, it generates an electric potential (voltage).

“Conversely, an electric potential applied to the PZ cantilever causes it to bend. So, when a single BZ-PZ unit is wired to another such unit, the expansion of the oscillating BZ gel in the first unit deflects the piezoelectric cantilever, which produces an electrical voltage. The generated voltage in turn causes a deflection of the cantilever in the second unit; this deflection imposes a force on the underlying BZ gel that modifies its oscillations. The resulting see-saw-like oscillation permits communication and an exchange of information between the units.”

Multiple BZ-PZ units can be connected in serial or parallel, allowing more complicated patterns of oscillation to be generated and stored in the system. In effect, these different oscillatory patterns form a type of memory, allowing the material to be used for computation. Levitan adds, however, that the computations would not be general purpose, but rather specific to pattern-matching and recognition, or other non-Boolean operations.

Said Levitan: “Imagine a group of organ pipes, and each is a different chord. When you introduce a new chord, one resonates with that particular pattern. Similarly, let’s say you have an array of oscillators and they each have an oscillating pattern. Each set of oscillators would reflect a particular pattern. Then you introduce a new external input pattern, say from a touch or a heartbeat. The materials themselves recognize the pattern and respond accordingly, thereby performing the actual computing.”

Developing so-called “materials that compute” addresses limitations inherent to the systems researchers currently use to perform either chemical computing or oscillator-based computing. Chemical computing systems are limited by both the lack of an internal power system and the rate of diffusion as the chemical waves spread throughout the system, enabling only local coupling. Further, oscillator-based computing has not been translated into a potentially wearable material. The new hybrid BZ-PZ model solves these problems and points to the potential of designing self-powered synthetic material systems.

Balazs and Levitan note that the current BZ-PZ gel model oscillates in periods of tens of seconds, which would allow for simple non-Boolean operations or pattern recognition of patterns like human movement. The next step is to add an input layer for the pattern recognition, something that will be applied to self-oscillating gels and piezoelectric films for the first time.

The research is being funded by a National Science Foundation Integrated NSF Support Promoting Interdisciplinary Research and Education (INSPIRE) grant, which focuses on scientific problems that lie at the intersection of traditional disciplines.

—Compiled by Marty Levine

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The University Times Research Notes column reports on funding awarded to Pitt researchers as well as findings arising from University research.

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