Overcoming cardiac pacemaker "source-sink mismatch"

Instead of complication-prone electronic cardiac pacemakers, biomedical engineers at Georgia Tech and Emory envision the creation of “biological Read more

Hope Clinic part of push to optimize HIV vaccine components

Ten years ago, the results of the RV144 trial– conducted in Thailand with the help of the US Army -- re-energized the HIV vaccine field, which had been down in the Read more

Invasive cancer cells marked by distinctive mutations

What does it take to be a leader – of cancer cells? Adam Marcus and colleagues at Winship Cancer Institute are back, with an analysis of mutations that drive metastatic behavior among groups of lung cancer cells. The findings were published this week on the cover of Journal of Cell Science, and suggest pharmacological strategies to intervene against or prevent metastasis. Marcus and former graduate student Jessica Konen previously developed a technique for selectively labeling “leader” Read more

News

Clinical trial for patients with atrial fibrillation tests implantable device in place of blood-thinning drug

Clinical Trial for Patients with A-fib

A new clinical trial underway for patients with atrial fibrillation will test an implantable device in place of a common blood-thinning medication, according to researchers at Emory University Hospital Midtown.

Atrial fibrillation (commonly called A-fib) is a heart condition in which the upper chambers of the heart beat too fast, causing an irregular heartbeat and ineffective pumping action. This condition can cause blood to pool and form clots in the left atrial appendage (LAA). If a clot forms in this area, it can increase the chances of having a stroke.

Many patients with A-fib are prescribed blood-thinning medications, such as warfarin (brand name Coumadin), to prevent blood from clotting. This medication is effective in reducing the risk of stroke, but may cause side effects such as bleeding. It also requires frequent blood draws to monitor dosage levels.

The trial, called PREVAIL (Prospective Randomized EVAluation of the Watchman LAA Closure Device In Patients with Atrial Fibrillation Versus Long Term Warfarin Therapy), involves implanting a small, umbrella-shaped mesh device called the Watchman closure device, into the heart chamber via catheter. This is a confirmatory study (and the third study testing the implant), which will also look at safety and efficacy of the device.

David De Lurgio, MD, associate professor of medicine in the Division of Cardiology, Emory University School of Medicine, is the principal investigator of the trial. He explains that by implanting this device into the left atrial appendage of the heart, it closes that area off. That, in turn, prevents blood clots from escaping and entering the blood stream, which could lead to a stroke.

Patients are randomly selected by computer to either receive the device or remain on Coumadin without the device (control group). Those selected to receive the device will remain on Coumadin for 45 days following implant. If the heart tissue has healed after those 45 days, participants will be taken off Coumadin and placed on aspirin therapy and possibly clopidogrel (Plavix), an anti-platelet medication.

Researchers will then follow study patients with and without the device for five years, monitoring those who are no longer taking Coumadin very closely. If the FDA approves the device at the end of this clinical trial, participants in the control group will then have the option to receive the device.

De Lurgio and his colleagues have had five years of experience with this technology, thus far. Emory Healthcare is the only health system in Georgia providing access to this device through participation in this clinical trial.

For more information, please call 404-686-2504.

Posted on by Janet Christenbury in Uncategorized Leave a comment

One reason why SIV-infected sooty mangabeys can avoid AIDS

Sooty mangabeys are a variety of Old World monkey that can be infected by HIV’s cousin SIV, but do not get AIDS. Emory immunologist and Georgia Research Alliance Eminent Scholar Guido Silvestri, MD, has been a strong advocate for examining non-human primates such as the sooty mangabey, which manage to handle SIV infection without crippling their immune systems. Silvestri is division chief of microbiology and immunology at Yerkes National Primate Research Center.

Research shows sooty mangabeys have T cells that can do the same job as those targeted by SIV, even if they don't have the same molecules on their surfaces

A recent paper in the Journal of Clinical Investigation reveals that sooty mangabeys have T cells that perform the same functions as those targeted by SIV and HIV, but have different clothing.

Silvestri and James Else, the animal resources division chief at Yerkes, are co-authors on the paper, while Donald Sodora at Seattle Biomedical Research Institute is senior author.

One main target for SIV and HIV is the group of T cells with the molecule CD4 on their surfaces. These are the “helper” T cells that keep the immune system humming. Doctors treating people with HIV infections tend to keep an eye on their CD4 T cell counts.

In the paper, the scientists show that sooty mangabeys infected with SIV lose their CD4 T cells, without losing the ability to regulate their immune systems. What’s remarkable here is that sooty mangabeys appear to have “double negative” or DN T cells that can perform the same functions as those lost to SIV infection, even though they don’t have CD4.

CD4 isn’t just decoration for T cells. It’s a part of how they recognize bits of host or pathogen protein in the context of MHC class II (the molecule that “presents” the bits on the outside of target cells). Somehow, the T cells in sooty mangabeys have a way to get around this requirement and still regulate the immune system competently. How they do this is the topic of ongoing research.

The authors write:

It will be important to assess DN T cells in HIV-infected patients, particularly to determine whether these cells are preserved and functional in long-term nonprogressors. These efforts may lead to future immune therapies or vaccine modalities designed to modulate DN T cell function. Indeed, the main lesson we have learned to date from this cohort of SIV-infected CD4-low mangabeys may be that managing immune activation and bolstering the function of nontarget T cells through better vaccines and therapeutics has the potential to contribute to preserved immune function and a nonprogressive outcome in HIV infection even when CD4+ T cell levels become low.

Posted on by Quinn Eastman in Immunology Leave a comment

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 Leave a comment

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.

Posted on by Wendy Darling in Uncategorized 1 Comment

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 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.

Posted on by Robin Tricoles in Uncategorized 1 Comment

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.

Posted on by Holly Korschun in Neuro Leave a comment

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.

Posted on by Wendy Darling in Uncategorized Leave a comment

Tobacco free cities project aims to curb smoking in China

Jeffrey Koplan, MD, MPH

Jeffrey Koplan, MD, MPH, director of the Emory Global Health Institute and vice president for Global Health at Emory University, is leading the second phase of the Tobacco Free Cities project in China, funded by the Bill and Melinda Gates Foundation. The project, which launched in 10 Chinese cities this week, is a partnership with the ThinkTank Research Center for Health Development in Beijing.

Vice mayors of each of the 10 cities signed an official pledge to strive to create tobacco-free cities for residents. China has more than 300 million smokers, the most of any country, and more than 500 million people in China are exposed to secondhand smoke.

“The two-year project aims to enhance the overall capacity in smoking-tobacco control of the cities and help ease the burden caused by tobacco to public health, the environment and the economy,” Koplan says in an article in China Daily.

The project launch was covered by other major Chinese news outlets, including Xinhua News Agency.

The first phase of the Tobacco Free Cities project launched in June 2009 in seven Chinese cities. The project is part of the Emory Global Health Institute-China Tobacco Partnership. In January 2009 Emory University received a $14 million, five-year grant from the Gates Foundation to establish the partnership.

Posted on by Holly Korschun in Uncategorized 2 Comments

Winter Storm 2011

Emory Healthcare puts patients first and provides 24 hour service to Atlanta Metro residents with doctors, nurses and staff staying in facilities to provide healthcare during one of the worst snow and ice storms to hit North Georgia in decades.

Here’s a television report that aired this evening at 5:24 pm on Atlanta’s WSB-TV Channel 2, (ABC affiliate).

WSB-TV report on Emory Healthcare during the January 2011 ice storm

Click for full report from WSB-TV, plus related article

Posted on by Wendy Darling in Uncategorized Leave a comment
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