Emory Vaccine Center researcher Cynthia Derdeyn and her colleagues have a new paper in PLOS Pathogens that is a reality check for researchers designing possible HIV vaccines. The results come from a collaboration with the Rwanda Zambia HIV Research Group. (Although the patients in this paper are from Zambia only.)
Red and green depict the parts of the HIV envelope protein that mutated in two patients (185F and 205F) in response to pressure from their immune systems.
Recently there has been some excitement over the discovery of robust neutralizing antibodies in patients.
The bottom line, according to Derdeyn’s team: even if a vaccine succeeds in stimulating antibodies that can neutralize HIV, the virus is still going to mutate furiously and may escape those antibodies. To resist HIV, someone’s immune system may need to have several types of antibodies ready to go, their results suggest.
A companion paper in the same issue of PLOS Pathogens from South African scientists has similarly bracing results.
Today is World Alzheimer’s Day 2009 and Emoryâ€™s Alzheimer’s Disease Research Center is part of an effort nationwide to address this disease through research and state-of-the-art care for patients.
Allan Levey, MD, PhD, chair of Emoryâ€™s Department of Neurology and an Alzheimerâ€™s researcher and clinician, says millions of baby boomers are entering late adulthood and experts expect the number of patients with Alzheimer’s disease to increase drastically over the next several decades. Prevention and early detection are extremely important, he says.
Emory’s Center is a National Institute on Aging funded center focused on clinical trials and research for Alzheimer’s disease. It is the only comprehensive program in Georgia and one of only 32 nationwide.
Levey, who directs the Center, offers the tips for good brain health:
Stay socially active
Remaining socially engaged in activities that stimulate the mind and body can reduce stress levels and help maintain healthy connections among brain cells.
Stay active, say experts
Be physically active
Exercising your body regularly is vital for maintaining good blood flow to the brain and encouraging the growth of new brain cells.
Stay mentally active
Your brain needs mental stimulation to allow it to function at its peak. Research shows that keeping the brain active helps increase its vigor and may strengthen brain cells and the connections between them, and may even generate new ones.
Protect your head
Injury to the head can increase your risk of dementia as you get older. Make sure you wear a helmet when you ride a bike, skate, ski or engage in any activity where you may injure yourself.
Eat brain healthy foods
The brain, like the heart, needs the proper balance of nutrients, including protein and sugar, to optimally function. According to current research, certain foods appear to protect brain cells so increase your intake of these protective foods.
Levey says scientists are finding more clues that high blood pressure, high cholesterol and diabetes may increase a person’s risk of getting Alzheimer’s disease. He says to keep your weight in a healthy range, lower your cholesterol if it is high and maintain control of your blood glucose and blood pressure.
Emory’s Cheryl Williams, RD, LD, clinical nutritionist for the Emory Heart & Vascular Center and Emory HeartWise Cardiac Risk Reduction Program, says you should make it a priority to know your cholesterol levels and learn how what you eat can impact cholesterol and your heartâ€™s health.
Since diets high in saturated fat and trans fat have been linked to chronic disease, specifically, heart disease, this knowledge could save your life.
During National Cholesterol Month Williams notes in her blog for the Atlanta Journal-Constitution’s “Doctor Is In” that eating too many fatty foods â€“ especially those high in saturated fat and trans fat â€“ is the primary cause of high cholesterol. Thin, active people may not be aware of how much bad fat they consume, she says.
According to Williams, “Saturated fats are derived primarily from animal products and are known to raise cholesterol levels. They are found in common foods like butter, cheese, whole milk, pork and red meat. Lower-fat versions of these foods usually contain saturated fats, but typically in smaller quantities than the regular versions. Certain plant oils, like palm and coconut oils, are another source of saturated fats. You may not use these oils when you cook, but they are often added to commercially baked foods, such as cookies, cakes, doughnuts and pies.
Even more detrimental to cholesterol levels are trans fats, artificially created during food processing when liquid oils are converted into solid fats â€” a process called hydrogenation. Many fried restaurant foods and commercially baked goods contain trans fats, as well as vegetable shortening and stick margarine. Read labels and avoid foods that contain partially or fully hydrogenated oils.”
The case report describes a woman with diabetes who needed surgery because of loss of blood flow to abdominal organs. While she is in intensive care after surgery, it becomes clear that a feeding tube leading from her nose to her stomach is not working. That makes her a good candidate for parenteral nutrition, or bypassing the digestive system and delivering nutrients directly into her blood.
Malnutrition is common in patients who are critically ill and often worsens with prolonged hospitalization. Some patients can’t eat normal food or benefit from a feeding tube into the stomach.
Thomas Ziegler, MD, Director, Center for Clinical and Molecular Nutrition, Department of Medicine
Yet few well-designed clinical trials studying parenteral nutrition have been conducted, Ziegler writes. He also notes that there is considerable debate over when parenteral nutrition is appropriate during critical care and how to administer it.
Ziegler’s own research has shown the beneficial effects of the amino acid glutamine, which must be added fresh to feeding formulas, for some critical care patients.
Several of the questions Ziegler outlines in his article will be issues investigators at Emory’s new Center for Critical Care will tackle. Recently, Timothy Buchman, MD, PhD, joined Emory to lead the critical care team.
With the sad news today of the death of actor Patrick Swayze, the public is again focused on pancreatic cancer and searching for more information on this aggressive cancer.
Recently, David Kooby, MD, Emory Winship Cancer Institute, and an assistant professor, Department of Surgical Oncology, authored a blog for the Atlanta Journal-Constitution’s “Doctor Is In” on this topic.
Pancreatic cancer is an aggressive malignancy that begins in the cells of the duct (or tube) running along the length of the pancreas. Each year about 42,000 new cases of pancreatic cancer are diagnosed and more than 35,000 people die from this cancer. A diagnosis of pancreatic cancer is usually made after discovery of a mass or a dilated duct in the pancreas.
Pancreatic cancer can be difficult to diagnose. Patients often come in for a doctorâ€™s visit with non-specific symptoms such as abdominal or back pain or weight loss. Some patients will develop jaundice (yellowing of the skin) as a result of the tumor blocking the duct draining bile from the liver
No one knows the exact causes of pancreatic cancer, although some risk factors are known through research that has been done.
A new study has shown that prairie voles may be a useful model in understanding the neurochemistry of social behavior. By influencing early social experience in prairie voles, researchers hope to gain greater insight into what aspects of early social experience drive diversity in adult social behavior.
Prairie voles are small, highly social rodents that often form stable, life-long bonds between mates. In the wild, there is striking diversity in how offspring are reared. Some pups are reared by single-mothers, some by both parents (with the father providing much of the same care as the mother) and some in communal family groups.
Researchers Todd Ahern, a graduate student in the Emory Neuroscience Program, and Larry Young, PhD, professor of psychiatry and behavioral sciences at the Yerkes National Primate Research Center and Emory School of Medicine, compared pups raised by single mothers (SM) to pups raised by both parents (BP) to determine the effects of these types of early social environments on adult social behavior.
The study showed SM- and BP-reared animals experienced different levels of care during the neonatal period and that these differences significantly influenced bonding social behaviors in adulthood. Pups raised by single mothers were slower to make life-long partnerships, and they showed less interest in nurturing pups in their communal families.
Researchers also found differences in the oxytocin system. Oxytocin is best known for its roles in maternal labor and suckling, but, more recently, it has been tied to prosocial behavior, such as bonding, trust and social awareness. Very simply, altering their early social experience influenced adult bonding.
Further studies will look at the altered oxytocin levels in the brain to determine how these hormonal changes affect relationships.
Emory’s Center for Health and Aging is addressing health care issues affecting the rapidly growing senior population in the United States through research, clinical care, community outreach and education.
One of the greatest challenges now facing the health care system in the United States is the rapid growth of the numbers of aging adults. It will have an unprecedented impact on the delivery of medical care, including supply of and demand for health care workers.
It is expected that the supply of health care providers may decrease at a time huge numbers of workers retire or reduce their working hours. And older adults consume a disproportionate share of American health care services, resulting in greater demand for services.
There are compelling demographic reasons to study aging. According to U.S. census records, a wave of 2.7 million Americans will turn 65 by 2011, and each succeeding year the swell gets higher until it peaks in 2025 with 4.2 million new 65-year-olds. By 2030, when the youngest boomers have become seniors, the number of Americans 65 and older is expected to be more than 70 million â€“ nearly twice as many as in 2005, according to a report by the National Academiesâ€™ Institute of Medicine
Ted Johnson, MD, MPH
Led by Theodore (Ted) Johnson II, MD, MPH, the Center benefits from well-established and successful programs in clinical care, aging research and education at Emoryâ€™s Wesley Woods Center, one of the nationâ€™s few campuses devoted to the health and well being of older adults.
Wesley Woods is one of the nationâ€™s most comprehensive centers for aging-related research, care and quality of life, serving more than 30,000 elderly and chronically ill patients each year through outpatient clinics, a hospital, skilled nursing care facility and residential retirement facility. In addition, Emory is affiliated with the Atlanta Veterans Affairs Medical Center, which has an extensive array of geriatric clinical, research and training programs.
The health care implications for seniors in Georgia and the U.S. are tremendous, according to Johnson. He says that the sheer numbers of older adults will place strains on our healthcare system and the family and professional caregivers who help them.
Johnson,who heads Emory’s Division of Geriatric Medicine and Gerontology, notes that itâ€™s the cumulative effect of that surge – plus the fact that people are living far longer than ever before – that poses a looming crisis for the health care system.
The idea that doctors could use stem cells to treat diseases ranging from amyotrophic lateral sclerosis (ALS) to stroke, spinal cord injury and heart disease has stimulated excitement and research funding over the last decade.
One critical obstacle is getting the stem cells to survive in the harsh environment of injured tissue and turn into the right kind of cell where they are needed. In both laboratory experiments and clinical trials, most of the stem cells usually die a few days after transplantation.
Exposing stem cells to reduced levels of oxygen may actually help protect them from the stressful process of being transplanted into the heart, according to recent research.
Shan Ping Yu and Ling Wei, who moved their laboratories about a year ago to Emoryâ€™s Department of Anesthesiology, were the first to show the effects of “hypoxic preconditioning.” Wei says the low oxygen strategy is a continuation of previous collaboration with Comprehensive Neurosciences Center director Dennis Choi. There, they had used the tactic of overexpressing BCl2, a gene that counteracts cell death, but the new approach avoids permanently altering the genes in stem cells, which may have long-term adverse effects.
Effects on mesenchymal stem cells' ability to implant into heart tissue in rats. In D, the stem cells were exposed to low oxygen but in C they were not. Blue shows all cell nuclei, while green shows implanted stem cells. The greater presence of yellow in C, a couple days after transplantation, displays the activation of an enzyme that leads to cell death. From the Journal of Thoracic and Cardiovascular Surgery.
In a way, this is consistent with the work of former Emory investigator Marie Csete, who showed that stem cells are happier and healthier in oxygen concentrations that reflect the levels they experience in the body: between 2 and 5%.
To achieve their protective effects, Yu and Wei are using oxygen concentrations of 0.5%. For comparison, room air has about 20% oxygen.
In an editorial, Yu, Wei and graduate student Molly Ogle discuss how they have been exploring whether inhibitors of enzymes that sense levels of oxygen in cells could have the same protective effects as exposure to low oxygen. Yu also reports that his group is studying how low oxygen helps stem cells home to target tissues better. Their hypothesis is that low oxygen stimulates cellsâ€™ motility — their ability to migrate into the right place. Wei’s research has shown that lower oxygen helps more stem cells to turn into neuronal cells.
A new study using brain imaging to study teen behavior indicates that adolescents who engage in dangerous activities have frontal white matter tracts that are more adult in form than their more conservative peers.
The brain goes through a course of maturation during adolescence and does not reach its adult form until the mid-twenties. A long-standing theory of adolescent behavior has assumed that this delayed brain maturation is the cause of impulsive and dangerous decisions in adolescence. The new study, using a new form of brain imaging, calls into question this theory.
In order to better understand the relationship between high risk-taking and the brain’s development, Emory University and Emory School of Medicine neuroscientists used a form of magnetic resonance imaging (MRI) called diffusion tensor imaging (DTI) to measure structural changes in white matter in the brain. The study’s findings are published in the Aug. 26, 2009 PLoS ONE.
“In the past, studies have focused on the pattern of gray matter density from childhood to early adulthood, says Gregory Berns, MD, PhD, principal investigator and professor of Psychiatry and Neuroeconomics at Emory University and director of the Center for Neuropolicy. “With new technology, we were able to develop the first study looking at how development of white matter relates to activities in the real world.”
Gray matter is the part of the brain made up of neurons, while white matter connects neurons to each other. As the brain matures, white matter becomes denser and more organized. Gray matter and white matter follow different trajectories. Both are important for understanding brain function.
Berns suggests that doing adult-like activities requires sophisticated skills.
“Society is a lot different now than it was 100 years ago when teens were expected to go to work and raise a family,” says Berns. “Now, adolescents aren’t expected to act like adults until they are in their twenties, when they have finished their education and found a career. Listen to Berns discuss the changing definition of adulthood.
An Emory project studying schizophrenia genetics is a good example of how geneticists are shifting from examining small, common mutations to “rare variants” when studying complex diseases.
From studies of twins, doctors have known for a long time that heredity plays a big role in causing schizophrenia. But dissecting out which genes are the most important has been a challenge.
Threelandmarkstudies on schizophrenia genetics published this summer illustrate the limitations of “genome wide association” studies. New York Times science reporter Nicholas Wade summarized the results in this way:
“The principal news from the three studies is that schizophrenia is caused by a very large number of errant genes, not a manageable and meaningful handful.”
The limitations from this type of study comes from the type of markers geneticists are looking at, says Steve Warren, chair of the human genetics department at Emory.
Genome wide association studies usually follow SNPs — single nucleotide polymorphisms. This is a one-letter change somewhere in the genetic code that is found in a fraction of the population. It’s not a big change in the genome, and in many cases, it will have a small effect on disease risk.
Researchers looking for the genes behind complex diseases such as schizophrenia and autism are starting to shift their efforts away from genome wide association studies, Warren says.
Think of a SNP like a misspelling of a word in a certain place in a book, he says. In contrast, the “rare variants” geneticists are starting to study more intensively are more like printers’ errors or missing pages. The rapid sequencing technology that allows scientists to investigate these changes easily is just now coming on line, he says.
One example of these rare variants is DiGeorge syndrome, a deletion that gets rid of dozens of genes on one copy of chromosome 22. Children who have this chromosomal alteration often have anatomical changes to their heart and palate. But it also substantially increases the risk of schizophrenia – to about 25% lifetime risk. That’s a lot more than any of the SNPs identified this summer.
Working with several Emory colleagues, researcher Brad Pearce is planning to examine the genes missing in DiGeorge syndrome in several groups of patients: people with DiGeorge, patients with “typical” schizophrenia and people at high risk of developing schizophrenia.
An article in this spring’s Emory Health describes genetic research on autism. Several of the researchers mentioned there, such as geneticist Joe Cubells and psychiatrist Opal Ousley, are involved in this schizophrenia project as well, because deletions on chromosome 22 also lead to an increased risk of autism.