Itâ€™s not a silly question, when one sees how oxidative stress and reactive oxygen species have been implicated in so many diseases, ranging from hypertension and atherosclerosis to neurodegenerative disorders. Yet large-scale clinical trials supplementing participantsâ€™ diets with antioxidants have showed little benefit.
Emory University School of Medicine scientists have arrived at an essential insight: the cell isnâ€™t a tiny bucket with all the constituent chemicals sloshing around. To modulate reactive oxygen species effectively, an antioxidant needs to be targeted to the right place in the cell.
Sergei Dikalov and colleagues in the Division of Cardiology have a paper in the July 9 issue ofÂ Circulation Research, describing how targeting antioxidant molecules to mitochondria dramatically increases their effectiveness in tamping down hypertension.
Mitochondria are usually described as miniature power plants, but in the cells that line blood vessels, they have the potential to act as amplifiers. The authors describe a â€œvicious cycleâ€ of feedback between the cellular enzyme NADPH oxidase, which produces the reactive form of oxygen called superoxide, and the mitochondria, which can also make superoxide as a byproduct of their energy-producing function.
Kathy Griendling, PhD (in green), surrounded by members of her lab
On June 15, 2010, vascular biologist Kathy Griendling delivered the 2010 Dean’s Distinguished Faculty lecture at Emory University School of Medicine.
Some of Griendling’s publications have been cited thousands of times by fellow scientists around the world, making her the lead member of a small group of researchers at Emory called theÂ “Millipub Club.”
With her five children and one grandson watching in the back row, Griendling explained how she and her colleagues, over the course of more than two decades at Emory, have gradually revealed the functions of a family of enzymes called NADPH oxidases in vascular smooth muscle cells. Read more
Emory faculty-physicians were honored May 20 at the annual Health Care Heroes Awards celebration sponsored by the Atlanta Business Chronicle. All three are featured in this week’s edition of the newspaper.
She was nominated by the Georgia Cancer Coalition and honored for her work in reducing breast cancer mortality by increasing breast cancer awareness and leading the effort to diagnose the disease earlier in a high-risk population of minority women.
Last September the Avon Foundation awarded $750,000 to the Winship Cancer Institute at Emory and the Avon Comprehensive Breast Center. The grant is being used to continue community outreach, education, clinical access, and four research studies that directly affect care for the underserved populations in Atlanta. Since 2000, the Avon Foundation has awarded nearly $11 million to Winship and Grady to support leading-edge breast cancer research projects and improve outcomes for underserved women diagnosed with breast cancer in Atlanta.
Allen Dollar, MD, assistant professor of medicine (Division of Cardiology), Emory School of Medicine, andÂ Grady Chief of Cardiology, wanted to help those in developing countries long before he went to medical school. He’s donated his time and expertise in places like Cambodia, Vietnam, El Salvador and Sri Lanka, using his vacations to teach and heal. For the last decade, through Children’s Cross Connections, he’s held clinics and taught medical students in Ethiopia.
International Conference on Medical Volunteerism met at Emory in April
Vivian Pinn, MD, associate director for research on womenâ€™s health, and director of the Office of Research on Womenâ€™s Health at NIH, opened the meeting with Emoryâ€™s conference chair, Nanette Wenger, MD, professor of medicine (cardiology), Emory School of Medicine, and chief of cardiology at Grady Memorial Hospital.
Nanette K. Wenger, MD
In a career that spans more than 50 years, Wengerâ€™s dedication to reducing womenâ€™s disability and death from cardiovascular disease has made her one of the countryâ€™s most-respected experts on coronary heart disease in women. In 2009, Wenger received the Lifetime Achievement Award from the American College of Cardiology.
Although Wenger has earned dozens of awards in her celebrated career, she says her greatest professional achievement has been to help change a major paradigm in cardiology: the assumption that heart disease affects only men. A half a century ago heart disease was thought of as a “man’s disease.”
Emory University Hospital is one of about 20 hospitals nationwide, and the only site in Georgia, to study this new technology – with 75 patients receiving new valves at Emory since the clinical trial started in October 2007. Researchers hope to receive U.S. Food and Drug Administration approval in late 2011.
The life threatening heart condition affects tens of thousands of Americans each year when the aortic valve tightens or narrows, preventing blood from flowing through normally.
Peter Block, MD
Peter Block, MD, professor of medicine, Emory School of Medicine, and colleagues are performing percutaneous aortic valve replacement as part of a Phase II clinical trial, comparing this procedure with traditional, open-heart surgery or medical therapy in high-risk patients with aortic stenosis.
The procedure provides a new way for doctors to treat patients who are too ill or frail to endure the traditional surgical approach.
During the procedure, doctors create a small incision in the groin or chest wall and then feed the new valve, mounted on a wire mesh on a catheter, and place it where the new valve is needed.
Peripheral artery disease affects millions of people in the United States. It’s basically hardening of the arteries (atherosclerosis) leading to problems with getting enough blood to the limbs. Symptoms of severe PAD include leg pain that doesn’t go away once exertion stops and wounds that heal slowly or not at all.
Lifestyle changes, medication and surgery can address some cases of PAD, but often the disease is not recognized until it has advanced considerably. At Emory, cardiologist Arshed Quyyumi has been exploring whether a patient’s own bone marrow cells can repair the arteries in his or her limbs.
Between 1994 and 2006, in-hospital death rates decreased among all patients, but decreased more strikingly in women than in men. The decreased risk of death was largest in women younger than 55 years (a 52.9 percent reduction) and lowest in men of the same age (33.3 percent). The absolute reduction in the risk of death among patients younger than 55 was three times larger in women (2.7 percent) than men (0.9 percent).
Vaccarino and her colleagues say a large part (93 percent) of this sharper decrease in mortality of younger women compared with men in recent years is due to the improved risk profile of women compared with men at the time of the heart attack hospitalization, perhaps the result of better recognition and management of coronary heart disease and its risk factors in women before the acute heart event.
Whatever the reason, the improvement indicates that we are headed in the right direction, says Vaccarino. Increased and ongoing awareness to the prevention of cardiovascular risk factorsâ€”by healthy diet, regular physical activity and avoidance of smoke and smokingâ€”is saving lives, she notes.
Just like diabetes and hypertension, depression is a prevalent medical condition that is highly treatable. However, if ignored, it appears to increase the risk for heart disease. Researchers at Emory are continuing studies related to the link between depression and heart disease as a result of a 2-year, $1.5 million grant from the National Institutes of Health (NIH) through the 2009 American Recovery and Reinvestment Act.
Vaccarino says although depression has been implicated as a risk factor for heart disease for many years, there is still question whether this is a causal association or whether there are other reasons why people who are depressed may be more likely to get heart disease. Clarification of these mechanisms will improve our understanding of the disease and ultimately point to more effective primary prevention strategies for the identification and treatment of high-risk individuals.
Vaccarino and her team will study twin males born between 1946 and 1956 from the Vietnam Era Twin Registry comparing one twin who has depression and one who does not. She says this is almost a natural experiment, allowing researchers to separate out genetics and influences from the environment or behavior.
Vaccarino will be looking at myocardial blood flow measured with PET, a common imaging technique of the heart. It can quantify exactly how much blood is going to the coronary arteries in the heart and carefully determine if depression is associated with decreased blood flow to the heart.
This grant builds on a previous project looking at the same population of twins and allows researchers to bring these twins back and compare two time points. Researchers measured myocardial blood flow with PET a few years ago and will now be able to monitor progression of heart disease over time
A new option for heart valve replacement is under study at Emory University Hospital. Cardiologists at the Emory Heart & Vascular Center are conducting groundbreaking research to study a non-surgical treatment option for patients with severe aortic stenosis, a narrowing of the aortic valve opening that affects tens of thousands of people each year. It is most common among elderly patients over 70 years of age, but can surface earlier in life in those with rheumatic heart disease or congenital abnormalities of the valve. Patients often develop symptoms of chest pain, shortness of breath, fainting spells and heart failure.
Peter Block, MD
Emory cardiologists, led by Peter Block, MD, FACC, professor of medicine, Emory School of Medicine, are performing percutaneous aortic valve replacement as part of a clinical trial, comparing this procedure with traditional, open-heart surgery or medical therapy in high-risk patients with aortic stenosis. It provides a new way for doctors to treat patients who are too ill or frail to endure the traditional surgical approach. So far, 115 people have participated in the phase II clinical trial.
In this new procedure, doctors create a small incision in the groin or chest wall and then feed a wire mesh valve through a catheter and place it where the new valve is needed. The standard therapy, which has been used to treat aortic stenosis for more than 30 years, is to remove the diseased valve through open-heart surgery.
Block says the results seen so far in this clinical trial show great promise for this procedure. He says this is especially important since tens of thousands of Americans are diagnosed with failing valves each year and that number is expected to increase substantially in the coming years as baby boomers pass the age of 70.