i on NIH Vodcast
May 11, 2009
“i on NIH” Vodcast Episode #0020
Welcome to “i on NIH”!
Featured in this month's episode are segments about the importance of eye exams, monitoring drug abuse in teens, and news about neural tube defects.
From the national institutes of health in Bethesda, Maryland - America’s premiere medical research agency - this is "i on NIH"!
Covering health-research topics important to you and the nation, this public service vodcast is your information source from inside all 27 institutes and centers at NIH.
Half an hour, once a month, we’ll show you the excitement of advances and the important information that comes from medical research. And now, here’s your host, Joe Balintfy.
Host: Welcome to the 20th edition of I on NIH, thanks for joining us. Coming up in this episode we have a series of in-depth interviews. The first explores healthy vision and the importance of getting your eyes checked. The second is a special interview by a teen about teen drug abuse. And we’ll wrap up the show with an interview about how neural tube defects can be reduced.
But first, our news update. Here’s Harrison Wein from the NIH news-desk. What do you have for us this month, Harrison?
Harrison: Fat that could help keep off weight. And what’s occupying kids with autism.
Joe: I thought fat adds weight. But this first story is about brown fat. What is that?
Harrison: There are a least 2 different kinds of fat. You’re probably familiar with white fat. When you take in too many calories, your body stores that extra energy in white fat. To lose weight, you have to use more energy than you take in, which makes your body tap into its stores and break down the white fat for energy.
Brown fat is different. It burns up chemical energy to create heat and help maintain body temperature. Small mammals like rodents have it throughout their lives. People have it when they’re born, but we lose brown fat as we age. By adulthood, researchers thought, our brown fat was essentially nonexistent. But it’s been difficult to actually measure brown fat.
A team of scientists in Boston supported by NIH set out to measure brown fat directly. They looked in almost 2,000 adults for the uptake of a labeled sugar molecule in whole-body scans. Cells that take up this sugar are metabolically active. In fat tissue, that means the presence of brown fat.
Joe: And they found some in these adults?
Harrison: They were able to spot it in many of the people-more in women than men. The most common area they saw it in was a region of the neck.
Here’s the really interesting part: The less brown fat the researchers detected, the more likely the person was to have some extra weight on them, especially in older people. That suggests a potential role of brown fat in adult metabolism.
Two other research groups published companion papers showing that brown fat seems to play a role in regulating body temperature in adults.
Joe: This seems pretty exciting.
Harrison: Absolutely, Joe. Now that we know adults have this stuff, if researchers could figure out how to stimulate the tissue to burn more energy, it could be a way to fight obesity.
Joe: That’s fascinating, Harrison. Now, the next story is about autism spectrum disorders.
Harrison: People with autism spectrum disorders generally have trouble with social interactions and communication. One of the hallmarks of these disorders is an unusual pattern of eye contact during social interactions, particularly a tendency to look toward people’s mouths rather than their eyes.
NIH-funded researchers at the Yale Child Study Center wanted to understand what children with autism spectrum disorders were paying attention to. They tracked eye movements of 2-year-olds with and without autism spectrum disorders while the toddlers looked at cartoons on split-screen displays. The cartoons played normally on one half of the screen, but upside-down and in reverse on the other half. The normal soundtrack of the actor’s voice, recorded when the animations were made, was playing along.
The typically developing toddlers and developmentally delayed but non-autistic toddlers clearly preferred the upright animations. The toddlers with autism spectrum disorders had no preference-except in one animation.
These toddlers shifted their attention to the upright figure 66% of the time-that’s a strong preference-during a game of pat-a-cake, where the figure claps his hands repeatedly. The researchers realized that what made this animation unique was that the movement seemed to cause the clapping sound. The synchrony of action and sound only existed on the upright side of the screen; the inverted figure on the other side was played in reverse and so its motions weren’t in sync with the soundtrack.
Now, if kids with autism spectrum disorders have a preference for audiovisual synchrony, that would explain why they look more at peoples’ mouths than their eyes. The mouth is the facial feature with the most audiovisual synchrony, with lip motion matching the sounds of speech.
So the researchers did follow-up experiments with new animations and confirmed that’s what was happening.
Joe: So how does this give us insight into how autism spectrum disorders actually develop?
Harrison: From within days of birth, children pay special attention to what researchers call biological motion, like human movement. By 3 months, infants already prefer to look more at a person’s eyes than other parts of the face. But toddlers with autism spectrum disorders don’t pay special attention to human movement. And researchers believe these toddlers are missing the rich social information that’s imparted by biological motion. That’s likely affecting the course of their development.
If scientists can design ways to redirect the visual attention of these children, it might prove effective in treating these disorders.
Joe: That’s encouraging news, Harrison. And where can people find out more about these studies?
Harrison: Read about these and other NIH research studies in "NIH Research Matters." Go to the NIH home page and click the link on the right-hand side, under "In the News" that says, "eColumn: NIH Research Matters."
Joe: And what’s in this month’s health newsletter?
Harrison: Joe, tobacco is the leading cause of preventable death nationwide. The May "NIH News in Health" cover story is about how to quit smoking. And among other things, we also have a story about the importance of getting regular eye exams.
Joe: And where can people find that?
Harrison: That’s at news-in-health-dot-nih-dot-gov.
Joe: Thank you Harrison
Harrison: Thank you Joe.
Host: May is Healthy Vision Month. For this interview, we talked with Dr. Janine Austin Clayton, an ophthalmologist and deputy director of NIH’s Office of Research on Women’s Health. The first question. . .
Q: Why is it important to pay attention to your eyes?
Dr. Clayton: So 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.
Q: Even when you aren’t having eye problems?
Dr. Clayton: One of the points that people often don’t understand is that eye symptoms can go unnoticed and without an eye exam by an eye care professional, a dilated, comprehensive eye exam that looks at all the aspects of the eye, you cannot be sure that your eyes are healthy.
Q: Are there symptoms of eye diseases to look for?
Dr. Clayton: Many eye diseases have no early warning signs, and that’s a very important point. You may not notice anything. So it’s critical to have a regular eye examine on a basis, the frequency is determined by your age and your family history, but a regular eye exam to determine if there are problems. A complete eye examine including all aspects of the eye.
Q: What is involved with a complete eye exam?
Dr. Clayton: Everything from eye movement, the reaction of the pupil in the eye to light, the front part of the eye with a machine that we call a slit lamp, the back of the eye, the inside of the eye, the retina, which is the part of the eye that you actually with, the vision sensing part of the eye, and to look at that completely it requires the pupil to be dilated so that the doctor or the eye care provider can see all parts of the eye: the retina, the optic nerve, which is the nerve that takes the message that you’re seeing from the eye to the brain. All of those are important parts of the eye and unless each of them is working well, they can affect your vision. 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.
Q: What is glaucoma?
Dr. Clayton: In glaucoma the eye pressure and other aspects of the eye structure including the blood vessels are affected and the optic nerve could be damaged.
Q: What are some other common vision problems?
Dr. Clayton: Some of the other common vision problems are refractive error. That is the need for glasses or correction of an error in the eye, that is the eye does not refract or bend light perfectly so that you have 20/20 vision. It’s like looking through a camera that’s out of focus either one way or the other. And that affects about 14 million Americans.
Q: What kind of refractive errors are there?
Dr. Clayton: The most common refractive error is nearsightedness, which is also called myopia. And people who are near-sighted have a difficulty seeing objects that are at a distance. Up close they’re fine. They can read small print, they can bring items closer to the eye and they can see them, but at a distance: street signs, small print, the theater, movie theaters, that’s difficult for people who are near-sighted or myopic.
Dr. Clayton: Another form of refractive error is kind of the opposite in that it is farsightedness or hyperopia, and people who are farsighted have difficulty, sometimes, seeing up close. Distance is fine, so often people who are farsighted don’t really know it, they can see up close but it’s difficult.
Q: Are eye diseases age related?
Dr. Clayton: Age is a risk factor for many eye diseases. Age related macular degeneration, which is the leading cause of blindness in white Americans, age is the number one risk factor. Age is a risk factor for glaucoma as well, and cataract is an aging problem. Cataract is a clouding of the lens of the eye, the part of the eye that’s like a lens on a camera that helps you focus, and it can become cloudy or hazy over time, and age is the primary risk factor for that.
Dr. Clayton: Age is a risk factor for presbyopia as well. Most of us as we become about 40 we notice that our arms aren’t long enough, and if we pull the material out farther away we look a distance, it becomes clearer, we have difficulty reading menus in restaurants, in darker conditions that can be more difficult.
Dr. Clayton: it’s just another thing that happens to your eyes and reason to see your eye care provider to make sure there’s nothing else going on, that there’s no other reason for that.
Q: What other eye-health issues are important to consider?
Dr. Clayton: Particularly important and common eye problems include diabetic retina or the diabetic eye disease. Diabetes can cause very serious problems in the eye: Bleeding in the back of the eye, swelling in different parts of the retina can promote cataract formation, and those are very, very serious causes of vision loss in this country.
Q: Do eye problems affect men and women differently?
Dr. Clayton: Despite some of the issues that we do understand about differences between men and women, there are many things we don’t understand about why the fact is that there are more women affected by many of these eye diseases than men, and worldwide if you look at the number of people that are visually impaired or even blind, legal blindness or other categories, there are more women than men in those groups. Some of the cases we understand that because women live longer than men, there are more older women than older men and age is a primary risk factor as we discussed for glaucoma, age-related macular degeneration, cataract, which are leading causes of visual impairment, but some of the time we don’t understand why it is that there are more women that are visual impaired than men.
Dr. Clayton: One of the other points is that many of us take care of a lot of other people in our families, especially women. We tend to take care of our spouses, our partners, our friends, our children, our grandparents, our parents, everybody and often leave ourselves for last. And one of the problems with that is that you’re not going to be in a position to really take care of others that you care about if you’re not healthy yourself.
Joe: For more information about the importance of eye health, visit www.nei.nih.gov/healthyeyes.
Host: There are signs that the ongoing decline in teen marijuana use in recent years has stalled; however the downward trend in cigarette and alcohol use continues, according to the most recent annual survey of teen drug abuse, called "Monitoring the Future." For this special interview, high school senior Lillian Rosen talks to the Director of the National Institute on Drug Abuse, Dr. Nora Volkow.
Lillian: Hi, I’m Lillian Rosen and I’m here to interview you and ask you a couple questions about the Monitoring the Future survey.
Dr. Volkow: Hi-how are you? Nice to meet you.
Lillian: Can you tell me what exactly Monitoring the Future is?
Dr. Volkow: Monitoring the Future is a project that was started at the National Institute on Drug Abuse in 1975, and the idea is to survey schools across the United States to get an indication about what are the trends of drug use, and it started in 1975 and we currently survey on an annual basis 48,000 kids, approximately 380 schools — the whole United States gets surveyed. And we had some questions about have they taken drugs, licit, illicit, how frequently have they taken, once in a lifetime, yearly, daily. And we also ask them about attitude — that is to say, do you think these drugs are harmful? Do you think that other kids are taking drugs?
Dr. Volkow: The idea is to conduct a survey that is representative of all genders and socioeconomical classes and backgrounds. It targets eighth, and 10th, and 12th graders, but there is a lot of work that goes on in order to select schools that are representative of the diversity that we have in high school students in the United States.
Lillian: How will the study prevent or eliminate teen drug abuse?
Dr. Volkow: The study does not prevent or eliminate, but gives us information that as an institute and as a country can guide us where there may be worrisome trends. For example, for the past, I would say, five years, we have seen a significant increase in the abuse of prescription medication, which was not something that high school students did in the past. Had we not done this survey, we would be still believing that the only thing that high school students are using are the classical illegal substances — marijuana, perhaps cocaine, perhaps a little bit of LSD, perhaps methamphetamines — whereas what we’re now seeing is that the number two drug in terms of frequency of abuse are prescription medications.
Lillian: Were there any sharp increases in data regarding tobacco usage and marijuana usage?
Dr. Volkow: Well, you know, over the past five years we’ve been seeing declines in the use of marijuana and most illicit substances. But this year, it seems to have stabilized. The major illicit substance abused by kids is marijuana. And 12th-graders, for example, have 33 percent of them report that they have used it in the past year; 33 percent, more than one in three. So that’s a big number. Now, even though that has gone down, it’s still very high and that has stabilized.
Lillian: Was there anything surprising in the data? If so, what was it?
Dr. Volkow: Not in the data — I was not surprised, actually. As I say, the rates this year have stabilized for the illicit substances. And we have seen this decline in cigarette smoking, so I was delighted that we’re still seeing it going down, because even though it has been going down, you can always look at it, I think still we have an enormous amount of work to go ahead of us. Still, 10 percent of your seniors are smoking cigarettes regularly, close to six percent smokes more than half a pack a day. So that’s a lot. You think in terms of numbers and consequences, that’s a lot.
Lillian: Over the counter medication usage is becoming a national epidemic. Has anything changed?
Dr. Volkow: Unfortunately, no. It’s an area that we’ve made very little dents. We’ve been aware that there’s been increases in the use of these medications, psychoactive medications — these are medications that are used for a wide variety of disorders. And there are three types actually, that are abused by high school students, but also by the general population. One of them are painkillers that have opiates, strong painkillers like Vicodin or OxyContin. The second type are stimulant medications, and these are medications that are used for attention deficit disorder, like the Ritalin or the Aderol.
Dr. Volkow: And the third one are medications that we call sedative-hypnotics, like benzodiazepines, that are utilized, for example, for people with sleep disorders to help them sleep, to help relax, as muscle relaxants. So these three classes of drugs are the ones that are being favored by high school students. The number one of those are pain medications.
Lillian: How does drug abuse affect development? Brain development?
Dr. Volkow: We are starting to actually also investigate, not just in terms of "you get exposed to drugs, that makes you greater risk for drug addiction," but asking questions about, "Well, if I get exposed to drugs as an adolescent, how does that affect the way that my brain is going to function as an adult, for example, in my ability to pay attention, and my ability to receive pleasure in my motivation?" Those are things that we don’t know, and we couldn’t study them in the past because we didn’t have the tools. Now that we have imaging technologies that allow us to directly look at how the human brain functions, investigators are starting to ask those questions, so I don’t have answers yet, now.
Lillian: What is your goal for the future?
Dr. Volkow: So, what I like to is, in terms — as we gain more knowledge in why people take drugs and what makes a person vulnerable to drugs, we may be able to tailor better prevention messages that will protect individuals from taking drugs, and those that may be taking them, prevent them from becoming addicted. That’s my hope in terms of what science will lead us to. And I also think science will lead us into better treatments. So you have already someone that is taking drugs, and is addicted — we could have better medications to help them stop taking those drugs, like we have medications that help people that have hypertension or asthma — that can help them lead better lives and be more successful. So, those are my two hopes.
Lillian: Thank you very much, Dr. Volkow
Joe: And thanks to Lillian Rosen. Along with the National Survey on Drug Use and Health, and the Youth Risk Behavior Survey, the Monitoring the Future Survey is one of three major government-sponsored surveys that provide data on substance use among youth. More information on Monitoring the Future can be found at www.drugabuse.gov.
Host: Now for our last interview of this episode. A recent study shows that children born to women who have low blood levels of vitamin B-12 shortly before and after conception, may have an increased risk of a neural tube defect. To learn more, we talked to Dr. James Mills at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The first question:
Q: What are neural tube defects and how common are they?
Dr. Mills: The incidence rate, to start, is about one per 2,000. Now, it used to be one per thousand, and folic acid fortification of food has lowered the rate dramatically. And when the embryo is forming the central nervous system, it happens by folding a portion of the embryo into a tube, and that forms the brain and the spinal cord. And when that folding fails to be completed, and doesn’t close, then you can get a major defect in either the brain or the spinal cord. And these are both very devastating defects.
Q: What is this recent study showing about the connection between neural tube defects and vitamin B-12?
Dr. Mills: Well, as a little prelude, I should say that a major discovery a few years ago was that you could prevent a lot of neural tube defects by taking folic acid, and B12 is very closely related to folic acid bio chemically, and they are involved in one key reaction. And it’s been shown several times previously that people who have children with neural tube defects have lower vitamin B12 levels during pregnancy. So we wanted to pursue that, and find out just how high a level of B12 you needed to be protected from that risk.
Q: Was this study able to show that level?
Dr. Mills: Yes, and in fact, I think the most interesting thing about our findings it that women who have a deficiency level of B12 have about five times, a five hundred percent increase in the risk for having a baby with a neural tube defect. And women who have a level that’s sort of in the below normal, but not totally deficient range have about a three times increased rate. So that’s very important information for women who are trying to become pregnant.
Q: Why was the study conducted in Ireland?
Dr. Mills: Well, Ireland has traditionally had a very high level of neural tube defect problems in pregnancy. In fact, they call it "The Curse of the Celts," there, and it’s probably partially genetic, and partially because of diet. So we have been doing research there, because it’s an area where they have a lot of people with the problems, and it enabled us to find women who were not exposed to a lot of supplements that contained either folic acid or B12.
Q: What is the take home message for women who want to get pregnant?
Dr. Mills: Well, it’s very important that women get folic acid, because that is the major protective item, and although foods in the U.S. contain folic acid now, women should still take a supplement that has 400 micrograms of folic acid. The point that we’re making in our study, that’s new, is that women also should be aware of the fact that they need adequate B12. And two groups of women are at risk: those who are vegans, who may not be getting B12 in their diets; and women who have an absorption problem, any gastrointestinal problem that can interfere with vitamin absorption. And their physician should be able to tell them if they are at risk.
Joe: For more on this study, visit www.nichd.nih.gov. You can also find factsheets on folate and other dietary supplaments from NIH. Visit the website ods.od.nih.gov.
Host: And that’s it for another episode on I on NIH. If you’d like to see or forward individual segments from this program, they’re available on YouTube. Check out the NIHOD channel. Thanks for tuning in and please watch again next time. We’re working on stories about brain awareness and the relationship between sleep and cancer, plus much more. For I on NIH, I’m Joe Balintfy.
Narrator: "I on NIH" is a public service vodcast from the Department of Health and Human Servives. Produced by NIH News Media Branch, of the Office of the Director, Office of Communications and Public Liaison. Thanks for tuning in. We’ll be back again next month with another episode of "I on NIH."
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