Insights into Parkinson's balance problems

In PD, disorganized sensorimotor signals cause muscles in the limbs to contract, such that both a muscle promoting a motion and its antagonist muscle are Read more

Cajoling brain cells to dance

“Flicker” treatment is a striking non-pharmaceutical approach aimed at slowing or reversing Alzheimer’s disease. It represents a reversal of EEG: not only recording brain waves, but reaching into the brain and cajoling cells to dance. One neuroscientist commentator called the process "almost too fantastic to believe." With flashing lights and buzzing sounds, researchers think they can get immune cells in the brain to gobble up more amyloid plaques, the characteristic clumps of protein seen in Read more

Research

Emory/Georgia Tech: partners in creating heart valve repair devices

Vinod Thourani, associate professor of cardiac surgery at Emory School of Medicine, along with Jorge Jimenez and Ajit Yoganathan, biomedical engineers at Georgia Tech and Emory, have been teaming up to invent new devices for making heart valve repair easier.

At the Georgia Bio and Atlanta Clinical and Translational Science Institute’s second annual conference on academic/industry partnerships, Thourani described how he and his colleagues developed technology that is now being commercialized.

Apica Cardiovascular co-founders (l-r) James Greene, Vinod Thourani, Jorge Jimenez and Ajit Yoganathan

Apica Cardiovascular was founded based on technology invented by Jimenez, Thourani, Yoganathan and Thomas Vassiliades, a former Emory surgeon.

Thourani is associate director of the Structural Heart Program at Emory.

Yoganathan is director of the Cardiovascular Fluid Mechanics Laboratory at Georgia Tech and the Center for Innovative Cardiovascular Technologies.

The technology simplifies and standardizes a technique for accessing the heart via the apex, the tip of the heart’s cone pointing down and to the left. This allows a surgeon to enter the heart, deliver devices such as heart valves or left ventricular assist devices, and get out again, all without loss of blood or sutures.

Schematic of transapical aortic valve implantation. The prosthesis is implanted within the native annulus by balloon inflation.

At the conference, Thourani recalled that the idea for the device came when he described a particularly difficult surgical case to Jimenez.  Thourani said that a principal motivation for the device came for the need to prevent bleeding after the valve repair procedure is completed.

With research and development support from the Coulter Foundation Translational Research Program and the Georgia Research Alliance VentureLab program, the company has already completed a series of pre-clinical studies to test the functionality of their device and its biocompatibility.

Posted on by Quinn Eastman in Heart 1 Comment

University-industry partnerships: a matter for cautious aggressiveness

Emory President James Wagner was keynote speaker last week at the 2011 Academic & Industry Intersection Conference sponsored by Georgia Bio and the Atlanta Clinical & Translational Science Institute (ACTSI). The conference focused on ethical issues in translating academic research into commercial drugs and medical devices.

Wagner pointed out the great power these relationships hold for the service of humanity, provided they are properly structured and managed. He recommended “cautious aggressiveness” by both universities and industry.

We should incorporate ethical considerations into our partnerships so that the practice of ethics is not “restrictive and paralyzing, but instead becomes part of the design criteria motivating our success, not restricting it.

Wagner is co-chair of President Obama’s Commission for the Study of Bioethical Issues. The commission lists five principles with broad application for biomedical translational research: public beneficence; responsible stewardship; intellectual freedom and responsibility; democratic deliberation; and justice and fairness.

He emphasized that researchers should guard against personal conflicts of interest and ensure against any compromise of research objectivity. But he cautioned against the temptation to value the process of ethics more highly than the ethical principles themselves, and the temptation to substitute compliance for true ethical practice.

Is it possible that we and our partners have come to place too much faith in documented protocols, and that excessive regulatory burden may give investigators a false sense of absolution of their own responsibility to exercise judgment and ethical practice? he asks.

“How does that square with the moral imperative to bring new knowledge that can benefit individuals and society to practice as soon as possible? Wouldn’t it be unethical to withhold the application of such knowledge if it is known to be able to do good?”

Ethical practice should not be an afterthought, Wagner emphasized, but instead a deeply understood and critical part of design and protocol and procedure — where the exercise of expert judgment goes beyond regulatory compliance.

“A challenge to all of our universities is to advance an ethics education that will bring heightened abilities to our investigators and their partners with the goal…of establishing even more trusting partnerships that can bring technology more safely and swiftly…from the minds of creative investigators, to the laboratory bench, to the manufacturing assembly line, to the vendor’s shelves, and to the bedside.”

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Study Finds Injection Drug Users Who Live Nearer to Syringe Exchange Programs Are Less Likely to Engage in HIV Risk Behaviors

Hannah Cooper

Hannah Cooper, ScD

Injecting drugs is one of the main ways people become infected with HIV in the United States. It is also the main way of becoming infected with the hepatitis C virus (HCV). Injection drug users (IDUs) become infected and transmit the viruses to others through sharing contaminated syringes and through high-risk sexual behaviors. Now a new study published in the American Journal of Public Health offers evidence that proximity to legal syringe exchange programs and pharmacies selling over the counter syringe plays a role in reducing the risk of HIV and Hepatitis C transmission in the U.S.

In a longitudinal study, Hannah Cooper, ScD assistant professor in the Department of Behavioral Sciences and Health Education at Emory University’s Rollins School of Public Health and colleagues studied the behaviors of more than 4000 drug injectors from across 42 New York City health districts beginning in 1995 to 2006. The scientists set out to determine if the relationship of spatial access to syringe exchange programs and pharmacies selling over-the-counter syringes affected the likelihood that local injectors engaged in less HIV risk behaviors.

“It is a well-established fact that syringe exchange programs reduce HIV and related risk behaviors among injection drug users. Here, what we find is that proximity to a syringe exchange program is a powerful determinant of whether injectors inject with sterile syringes,” says Cooper.

The CDC estimates an individual injection drug user injects as many as 1,000 times a year. This adds up to millions of injections across the country each year, creating an enormous need for reliable sources of sterile syringes. Syringe exchange programs provide a way for those IDUs who continue to inject, to safely dispose of used syringes and to obtain sterile syringes at no cost. Many U.S. cities have just one or two syringe exchange programs, but Cooper and her team found IDUs with access to these services in their local neighborhoods were more likely to inject with sterile syringes.

“Our findings suggest that having a syringe exchange program in your neighborhood matters. We need to dramatically scale up the number of syringe exchange programs operating in U.S. cities to increase the number of injectors who live near such a program,” says Cooper.

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Brain chemical linked to migraines could be anxiety target

Neuroscientist Michael Davis, PhD, and his colleagues have devoted years to mapping out the parts of the brain responsible for driving fear and anxiety. In a recent review article, they describe the differences between fear and anxiety in this way:

Fear is a generally adaptive state of apprehension that begins rapidly and dissipates quickly once the threat is removed (phasic fear). Anxiety is elicited by less specific and less predictable threats, or by those that are physically or psychologically more distant (sustained fear).

Michael Davis is an investigator at Yerkes National Primate Research Center and Emory School of Medicine

A host of their studies suggest that one part of the brain, the amygdala, is instrumental in producing “phasic fear,” while the bed nucleus of the stria terminalis (BNST) is important for “sustained fear.”

In a new report in the Journal of Neuroscience, Davis’ team describes the effects of a brain communication chemical, which is known primarily for its role in driving migraine headaches, in enhancing anxiety.

“This is the first study to show a role of this peptide, in a brain area we’ve identified as being important for anxiety.  This could lead to new drug targets to selectively reduce anxiety,” Davis says.

His team found that introducing calcitonin gene-related peptide (CGRP) into rats’ BNSTs can increase the anxiety they experience from loud noises or light, in that they startle more and avoid well-lit places. This peptide appears to activate other parts of the brain including the amygdala, hypothalamus and brainstem, producing fear-related symptoms.

Slice of rat brain showing the bed nucleus of the stria terminalis (BNST) and the central amygdala (Ce)

If Davis and his colleagues block CGRP’s function by introducing a short, decoy version of CGRP into the BNST, the reverse does not happen: the rats are not more relaxed. However, the short version does block the startle-enhancing effects of a smelly chemical produced by foxes that scientists use to heighten anxiety-like behavior in rats. This suggests that interfering with CGRP can reduce fear-related symptoms in situations where the rats are already under stress.

“Blockade of CGRP receptors may thus represent a novel therapeutic target for the treatment of stress-induced anxiety and related psychopathologies such as post-traumatic stress disorder,” says the paper’s first author, postdoctoral fellow Kelly Sink.

In fact, experimental drugs that work against CGRP are already in clinical trials to treat migraine headaches. But first, Sink reports that she and her colleagues are examining the relationship between CGRP and the stress hormone CRF (corticotropin-releasing factor) — another target of pharmacological interest — in the parts of the brain important for fear responses.

Posted on by Quinn Eastman in Neuro Leave a comment

HIV in metro Atlanta concentrated in four-county geographic cluster

The HIV epidemic in metropolitan Atlanta is concentrated mainly in one cluster of four metro area counties – Fulton, DeKalb, Clayton, and Gwinnett that includes 60 percent of Georgia’s HIV cases, according to a study by researchers in the Emory Center for AIDS Research (CFAR).

In a paper published in the Journal of Urban Health, the researchers found that the rate of HIV in the cluster is 1.34 percent. This fits the World Health Organization’s description of a “generalized epidemic” (>1 percent). Outside the cluster, the HIV prevalence in Georgia is 0.32 percent.

The researchers matched HIV prevalence data from the Georgia Division of Public Health, as of October 2007, to census tracts. They also used data from the 2000 census to examine population characteristics such as poverty, race/ethnicity, and drug use.

The large Atlanta HIV cluster is characterized by a high prevalence of poverty along with behaviors that increase the risk of HIV exposure such as injection drug use and men having sex with men.

The investigators also found that 42 percent of HIV service providers in Atlanta are located in the concentrated cluster, which should facilitate prevention and treatment.

Paula Frew, MPH, PhD

“A major aim of our study was to improve public health practice by informing local planning efforts for HIV services,” says corresponding author Paula Frew, MPH, PhD, assistant professor of medicine at Emory University School of Medicine and an investigator in the Emory CFAR.

With more than 50,000 new HIV infections reported yearly in the United States, according to the Centers for Disease Control and Prevention, the HIV/AIDS epidemic continues to be a major public health problem. The number of HIV/AIDS cases is increasing faster in the South compared to other areas of the country. According to Kaiser State Health Facts, Georgia ranks 9th in the nation in the number of HIV/AIDS cases with more than 3,000 new HIV infections diagnosed in 2007.

The study showed differences between Atlanta and other large cities in the distribution of HIV cases. While cases in several other large cities were concentrated in specific neighborhoods, HIV cases in metro Atlanta are more generalized within the four-county metro area. All the cities, however, were similar in the link between HIV, poverty and men having sex with men.

“Prevention efforts targeted to the populations living in this identified area, including efforts to address their specific needs, may be most beneficial in curtailing the epidemic within this cluster,” Frew says.

Other authors of the paper include Emory CFAR members Brooke Hixson, MPH; Saad B. Omer, MBBS, MPH, PhD; and Carlos del Rio, MD.

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Another avenue of HIV trickery reveals opportunity

Emory and University of Rochester researchers have discovered an extra way by which HIV adapts to survive in a hiding spot in the human immune system. The results are published in the Journal of Biological Chemistry.

A team led by Baek Kim from the University of Rochester and Raymond Schinazi from Emory found that when HIV faces a shortage of the building blocks it usually uses to replicate, the virus adapts by using different building blocks. The discovery may offer scientists a new way to try to stop the virus.

One of HIV’s favorite hiding spots is an immune cell called a macrophage, whose job is to chew up and destroy foreign invaders and cellular debris. One can think of macrophages as worker bees: they don’t reproduce because they’re focused on getting stuff done.

Raymond Schinazi, PhD, DSc, is director of the Laboratory of Biochemical Pharmacology at Emory's Center for AIDS Research

Normally, HIV uses “dNTPs” (building blocks of DNA), but dNTPs are found at very low levels in macrophages because they’ve stopped dividing and making new DNA. Current drugs generally target dNTPs, and aim at the infection in a different type of cells: T cells.

Macrophages do have high levels of RNA building blocks (“rNTPs”). The team found that HIV uses primarily rNTPs instead of dNTPs to replicate inside macrophages. When the team blocked the ability of the virus to interact with rNTPs, its ability to replicate in macrophages was cut by more than 90 percent.

“The first cells that HIV infects in the genital tract are non-dividing target cell types such as macrophages,” Kim says. “Current drugs were developed to be effective only when the infection has already moved beyond these cells. Perhaps we can use this information to help create a microbicide to stop the virus or limit its activity much earlier.”

Compounds that interfere with the use of rNTPs already exist and have been tested as anti-cancer drugs.

“We are now developing new anti-HIV drugs jointly based on this novel approach that are essentially non-toxic and can be used to treat and prevent HIV infections,” Schinazi says.

Baek Kim, PhD

The first authors of the paper are graduate students Edward Kennedy from Rochester and Christina Gavegnano from Emory. Other authors include graduate students Laura Nguyen, Rebecca Slate and Amanda Lucas from Rochester, and postdoc Emilie Fromentin from Emory.

The research was funded by the National Institute of Allergy and Infectious Disease and the Department of Veterans Affairs.

University of Rochester press release

Posted on by Quinn Eastman in Immunology 1 Comment

What’s left when it comes to research?

Cesare Lombroso

In an editorial appearing in a recent issue of The Lancet, Emory Rollins School of Public Health professor Dr. Howard Kushner contends that the connection between left-handedness and a raft of mental and physical disorders has gained currency since the 1980s and ‘90s.

Although Kushner acknowledges a long history of suspicion surrounding left-handedness, he spotlights one Cesare Lombroso, a Turin physician who spent a great deal of time in and around the 19th century pointing a negative finger at left-handedness. Lombroso’s contemporaries mistakenly considered his studies, albeit mere observations, to be cutting-edge science.

Although scientific standards have changed since Lombroso’s time and today’s studies do not portray left-handedness with such profound negativity, Kushner says, “general claims about the pathology of left-handedness persist.” This despite studies showing left-handers displaying exceptional intellectual and creative talents.

So, what are we to conclude about the connection between left-handedness and health? Kushner doesn’t say. Instead, he asks us to consider that despite all the advanced scientific tools we have at our disposal, researchers should keep in mind that these very tools may not enable us to conclusively explain the mystery behind left-handedness and its meaning. Yet, we should not stop trying. After all, he says, today’s researchers are making solid contributions to such research–while raising provocative questions along the way.

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New 3D MRI Technology Puts Young Athletes Back in Action

Emory MedicalHorizon
New technology has made it possible for surgeons to reconstruct ACL tears in young athletes without disturbing the growth plate.

John Xerogeanes, MD, chief of the Emory Sports Medicine Center and colleagues in the laboratory of Allen R. Tannenbaum, PhD, professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, have developed 3-D MRI technology that allows surgeons to pre-operatively plan and perform anatomic Anterior Cruciate Ligament (ACL) surgery.

Link to YouTube video

The ACL is one of the four major ligaments in the knee, somewhat like a rubber band, attached at two points to keep the knee stable. In order to replace a damaged ligament, surgeons create a tunnel in the upper and lower knee bones (femur and tibia), slide the new ACL between those two tunnels and attach it both ends.

Traditional treatment for ACL injuries in children has been a combination of rehabilitation, wearing a brace and staying out of athletics until the child stops growing – usually in the mid-teens – and ACL reconstruction surgery can safely be performed.  Surgery has not been an option with children for fear of damage to the growth plate that would cause serious problems later on.

Xerogeanes explains that prior to using the 3-D MRI technology, ACL operations were conducted with extensive use of X-Rays in the operating room, and left too much to chance when working around growth plates.

Preparation with the new 3-D MRI technology allows surgery to be completed in less time than the traditional surgery using X-Rays, and with complete confidence that the growth plates in young patients will not be damaged.

Video Answers to Questions on ACL Tears

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National Academy of Sciences recognizes Yerkes Primate Center neuroscientist

Elizabeth A. Buffalo, PhD

The National Academy of Sciences (NAS) has recognized 13 individuals with awards acknowledging extraordinary scientific achievements in the areas of biology, chemistry, physics, economics and psychology.

Elizabeth A. Buffalo, PhD, a researcher at the Yerkes National Primate Research Center, is one of two recipients of the Troland Research Awards. Buffalo is being honored for innovative, multidisciplinary study of the hippocampus and the neural basis of memory. Troland Research Awards of $50,000 are given annually to recognize unusual achievement by young investigators and to further empirical research in experimental psychology.

The recipients will be honored in a ceremony on Sunday, May 1, during the NAS 148th annual meeting.

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Renowned Scientist Recipient of Emory’s First Annual Neuroscience and Ethics Award

Michael Gazzaniga, PhD

Michael Gazzaniga, PhD, will deliver the lecture “Determinism, Consciousness and Free Will.”

Emory University Center for Ethics, Yerkes National Primate Research Center and The Neuroscience Initiative will present the First Annual Neuroscience and Ethics Award Lecture, “Determinism, Consciousness and Free Will” on January 18 at 4 pm at Emory’s Harland Cinema at the Dobbs University Center.

The guest speaker, and first to be recognized with this award, is Michael Gazzaniga, PhD, a scientist and author considered one of the pioneers in the emerging field of cognitive neuroscience.

“Dr. Gazzaniga is a world renowned scientists who, in addition to his other accomplishments, pioneered the study of split-brained patients and so revealed how the different hemispheres of our brains function,” says Paul Root Wolpe, PhD, director of the Emory University Center for Ethics.

“He has won our First Annual Emory Neuroscience and Ethics Award because, throughout his career, he has tried to apply his scientific understandings to improve the human condition, including serving on President Bush’s Bioethics Commission and publications such as his book The Ethical Brain.  I can think of no finer choice to be the first recipient of this Award.”

Gazzaniga founded and presides over the Cognitive Neuroscience Institute and is editor-in-chief emeritus of the Journal of Cognitive Neuroscience, which he also founded.  In addition, he is the one of the co-founders of the Cognitive Neuroscience Society, which was named in the late 1970’s.

In 1997, Gazzaniga was elected to the American Academy of Arts & Sciences.  He is the past-president of the Association for Psychological Science, served on the President’s Council on Bioethics and, in 2005, was elected to the National Academies Institute of Medicine. In 2009, he presented the Gifford Lectures at the University of Edinburgh.

Gazzaniga’s book The Ethical Brain describes in laymen’s language how the brain develops a value system, and the ethical dilemmas facing society as our comprehension of the brain expands.

For more information, contact Jamila Garrett-Bell.

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