May 1, 2009
NIH Podcast Episode #0083
Balintfy: Welcome to the 83rd episode of NIH Research Radio with news about the ongoing medical research at the National Institutes of Health—the nation's medical research agency. I'm your host Joe Balintfy and coming up in this episode: May is Healthy Vision Month, so we'll double cover this topic. Also, how prenatal exposure to smoking combined with genes, increases teens' risk for disruptive behavior problems. But first, some in-depth insight on influenza and flu pandemics. That's next on NIH Research Radio.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Understanding Influenza, Pandemic Flu
Balintfy: As we’re hearing more and more about the 2009 H1N1 influenza outbreak, now is a good time to get a refresher on exactly what influenza is, and what researchers are doing for future treatments. The flu, like the common cold, is a respiratory infection caused by viruses. But the flu differs in several ways from the common cold. For example, people with colds rarely get fevers or headaches or suffer from the extreme exhaustion that flu viruses cause. The most familiar aspect of the flu is the way it can "knock you off your feet" as it sweeps through entire communities.
Fauci: There are two reasons to be concerned about the flu.
Balintfy: Dr. Anthony Fauci is the director of the National Institute of Allergy and Infectious Diseases. He explains that one concern is that seasonal flu—a flu outbreak that occurs yearly—is itself a serious disease.
Fauci: And there’s also the threat of having what we call a pandemic flu.
Balintfy: Pandemic flu refers to particularly virulent strains of flu that spread rapidly from person to person to create a world-wide epidemic. Dr. Fauci says researchers are looking for ways to combat the flu.
Fauci: One of the best weapons against influenza is a vaccine that induces what we call neutralizing antibody. And a neutralizing antibody is an antibody that can actually block the virus in question. The trouble with the induction of neutralizing antibodies with flu is that they are usually directed against a component or portion of the virus that changes readily from strain to strain, and certainly changes when you have a pandemic virus or a pandemic strain. That’s the reason why each year we have to revaccinate people so that you can keep up with the drifting of the strains by mutations that occur.
Balintfy: The influenza virus is one of the most changeable of viruses with genes known for “drifting and shifting.” These genetic changes may be small and continuous or large and abrupt. Dr. Fauci points to a universal vaccine as a research target.
Fauci: The universal vaccine is one that you can give to an individual that would protect against an entire menu, as it were, of different strains of influenza.
(Scientists Identify Lab-Made Proteins That Neutralize Multiple Strains of Seasonal and Pandemic Flu Viruses)
Balintfy:Before this 2009 H1N1 influenza outbreak, scientists published a study about a small family of lab-made proteins that neutralize a broad range of influenza A viruses, including the H5N1 avian virus, the 1918 pandemic influenza virus and seasonal H1N1 flu viruses. Dorie Hightower has more in this report about seasonal flu and the latest research on fighting influenza.
Hightower: Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases says while very young infants and children, pregnant women, older individuals, and people whose immune systems are suppressed are especially vulnerable, even an otherwise young and healthy person can have a serious complication.
Dr. Fauci: There are 36,000 deaths per year in the United States, and more than 200—perhaps between 200,000 and 300,000 excess hospitalizations associated with the flu.
Hightower: Although vaccines are available, influenza viruses change quickly, creating new strains that require the development of new vaccines each year.
Fauci: So the goal of the kind of vaccine that you would want would be one that would induce an immune response against that part of that virus that doesn’t change readily.
Hightower: Scientists have now identified a small family of lab-made proteins that neutralize a broad range of influenza A viruses, including the H5N1 avian virus, the 1918 pandemic influenza virus and seasonal H1N1 flu viruses. These lab-made proteins potentially could be combined with antiviral drugs to prevent the flu, or even treat it during an outbreak.
Fauci: Now the study that was published has two components to it. One, it’s identified an antibody that one can make in large amounts that you could actually infuse into someone while you’re waiting to get the vaccine developed. That’s called passive immunization, and is more of a prophylactic treatment than it is a vaccine, because it’s not a vaccine. The other aspect of the paper that was interesting is that this particular antibody is able to identify the precise component of the virus to which you want to make a vaccine.
Hightower: Dr. Fauci says these findings could assist vaccine developers, with the goal of developing a universal vaccine.
Fauci: They call it universal because it covers all the different strains, or if not all, at least a significant proportion of them, whereas the influenza vaccine that we take this year, when the virus changes a bit next year, it’s not going to cover that very well. So you want a vaccine that, even though the virus changes, the vaccine still will be protective.
Hightower: For more on these findings and the latest research on prevention and treatment of influenza, go to www.niaid.nih.gov. This is Dorie Hightower, National Institutes of Health, Bethesda, Maryland.
Balintfy: To learn more about the swine flu, visit the CDC website www.cdc.gov/swineflu.
Healthy Vision Month, Part 1
Balintfy: May is Healthy Vision Month, a national eye health observance. The goal of Healthy Vision Month is to promote the importance of getting eye exams.
Dr. Clayton: It’s critical to get a complete eye exam.
Balintfy: Dr. Janine Austin Clayton is an ophthalmologist and deputy director of NIH’s Office of Research on Women’s Health. She says a comprehensive dilated eye exam involves looking at all the parts of the eye. It also tests eye movement, reaction to light and the fluid pressure inside.
Dr. Clayton: Just because you don’t have any problems seeing or other discomfort in your eye or pain, doesn’t mean you’re not having an eye problem. Without a complete eye exam that also involves checking the eye pressure, which is one of the screening tests for glaucoma, you cannot be sure that your eyes are healthy.
Balintfy: Dr. Clayton adds that eye health is a reflection of overall health. For example, sometimes diabetes can be diagnosis from changes in the eye. She also points out that refractive error, like nearsightedness or farsightedness, is a very common problem that affects about 14 million Americans.
Dr. Clayton: That’s a very prevalent condition, and importantly, though, even though there are so many Americans affected, about 11 million Americans can have that improved by proper correction, either with glasses, contact lenses, refracted surgery or some other refracted modality that corrects that, and they can get good vision from that.
Balintfy: All too often, people don’t have their eye examined until they start noticing problems with their vision. Having regular eye exams can help detect diseases in their early stages, when they can still be treated.
Dr. Clayton: The eye is certainly the window to the soul, the eye is the window to your health, and it’s a really, really critical part of the overall health and people need to take that into consideration as they’re thinking about their overall health. You know, you get your physical, you need to get your eye exam.
Balintfy: How often to have your eyes examined depends on age, family history and other risk factors. For more information about eye health, visit www.nei.nih.gov/healthyeyes.
Genes and Prenatal Exposure to Smoking Increases Teens’ Risk of Disruptive Behavior
Balintfy: We’ll have more from Dr. Clayton at the end of the program. Now we hear from Wally Akinso on how some teens are at higher risk of behavior problems.
Akinso: A National Institute on Drug Abuse study shows that prenatal exposure to smoking combined with a specific genetic variant places teens at greatest risk for behavioral problems. To the surprise of researchers, the genetic variant that confers this increased risk differs between boys and girls. When comparing the differences between the effects that prenatal exposure to smoking has on teenage boys and girls, researchers found a difference in phenotypes, which is any observable characteristic or trait of an organism. Dr. Nora Volkow is the Director of NIDA and she examines the differences between teenage boys and girls in this study.
Volkow: What they found was actually fascinating because they did find their prediction that in males, those males who’s mothers smoked during pregnancy and who have the gene variant that led to lower concentrations were the ones that have the more aggressive phenotypes. So these were the ones who were with conduct disorders was much more prevalent. On the other hand to the surprise of everybody, females it was the opposite. The interaction that increased the risk was when the newborn was a female and had the mother had smoked the increase risk for the conduct disorder occur with they genotype that coded for the high expression monoamine oxidase gene.
Akinso: A team of researchers led by the Institute for Juvenile Research at the University of Illinois at Chicago identified a long-lasting influence on behavior of the monoamine oxidase A gene variant following tobacco exposure before birth. Monoamine oxidase A is an enzyme which regulates chemical messengers in the brain. Dr. Volkow says these findings illuminate how the interaction between genes and the environment can mold behavioral patterns very early in development.
Volkow: This study is giving more evidence about the deleterious effects of smoking during pregnancy which is unfortunate still much more prevalent that we would want it to be. It is estimated that approximately 16 percent of women still smoke during pregnancy despite the fact there’s increasing evidence that smoking during pregnancy is deleterious to the newborn.
Akinso: Dr. Volkow says these findings provide researchers with clues to the possible mechanism by which prenatal exposure may exert its effects on the brain and behavior. For more information on these findings or other NIDA research visit www.drugabuse.gov. This is Wally Akinso at the National Institutes of Health, Bethesda, Maryland.
Balintfy: Stay tuned for some more, healthy-eye tips after this break.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Healthy Vision Month, Part 2
Balintfy: Dr. Janine Austin Clayton and I talked more about the importance of eye exams and eye health. One topic, was glaucoma.
Dr. Clayton: Glaucoma is a very important cause of blindness and visual impairment in the U.S., it’s particularly important in African Americans and in those who have a family history: Seven to eight times increased risk if you have a first degree relative with glaucoma, so that’s another point it’s important to know your eye family history as well as your family medical history. So often we’ll ask mom or pop or grandma if you have had cancer or heart disease, but we won’t think to ask, &quo;Well, have you ever had any eye problems? Is there a family history of glaucoma?&quo;
Balintfy: How would someone know if they have glaucoma, would they feel anything?
Dr. Clayton: Much like hypertension or high blood pressure can be painless, glaucoma can be painless. And unfortunately the type of vision that glaucoma affects first is the peripheral vision, the vision on the side and if the peripheral vision is affected often, we won’t notice that. And if you don’t notice it, the vision loss will continue to march centrally and at that point is often noticed but it is very—with progressed glaucoma you cannot regain the lost vision.
So you want to detect this early. You want to screen for it because there are many medications, surgical procedures, laser procedures, and other treatment modalities that can effectively treat glaucoma and present vision loss. So because it’s painless, because we can screen for it, because we have treatments, it’s critical for you to get your eyes checked and specifically to know your family history with glaucoma and to include an eye pressure test in your eye exam.
Balintfy: Most people probably think of an eye exam as checking for nearsightedness or farsightedness, but are there specific symptoms to refractive error?
Dr. Clayton: In any kind of refractive error there may be squinting, difficulty seeing, blurred vision, halos, just kind of unclear vision that is nonspecific, that doesn’t tell you what kind of refracted error. The only way to really determine that is to have the eye measured to have a refraction, which is the test where a machine is put in front of the eye, and we actually can calculate the error of the eye and what would need to be put into the glasses, spectacles, or contact lenses, or into the refractive laser treatment to correct the error in the eye.
Balintfy: Are there other areas of eye health that are worth emphasizing?
Dr. Clayton: There are categories of diseases, like autoimmune diseases, where the body’s immune system, which is supposed to help us fight infection, instead turns on itself and affects parts of the body including the eye. And dry eye is one example of one manifestation of an autoimmune disease, a specific one called Sjögren syndrome. Dry eye can also occur without autoimmune disease, but it is an inflammatory condition and in general inflammation disturbance in the immune cells of the body is more common in women than in men, and we don’t understand that.
So women have an added responsibility to get their eyes examined and we know that women are the portal to health for most of our families. We know that women are the ones that get their spouses, partners, friends, children to get their eyes examined, take them to the doctor, give eye protection to anybody working in their house with dangerous tasks, put eye protection on their children when they’re playing field hockey, lacrosse, or baseball. Women really can make a large impact on everyone by attending to these issues.
Balintfy: Thank you very much Dr. Janine Austin Clayton. You can see different parts of this interview in the NIH Vodcast, I on NIH. Check out I on NIH episode 20 on iTune or the NIH website, or look for the segment on YouTube, the NIHOD channel. For now, that’s it for this episode of NIH Research Radio. Please join us again on Friday, May 15 when our next edition will be available for download. I'm your host, Joe Balintfy. Thanks for listening.
NIH Research Radio is a presentation of the NIH Radio News Service, part of the News Media Branch, Office of Communications and Public Liaison in the Office of the Director at the National Institutes of Health in Bethesda, Maryland, an agency of the US Department of Health and Human Services.