September 10, 2010
NIH Podcast Episode #0117
Balintfy: Welcome to the 117th 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. Coming up in this episode: learning about how we learn, childhood obesity awareness, and understanding nanotechnology’s role in fighting cancer. But first, this news update; here’s Craig Fritz.
Fritz: A recent study funded by the National Institute on Aging found that men are more likely than women to experience mild cognitive impairment earlier in life. The condition, often a precursor to Alzheimer’s disease, is marked by memory problems. It appeared earlier than normal for 19 percent of men in a study of nearly 2,000 dementia-free adults. Comparatively, only 14 percent of women in the study showed signs of early decline. This notable difference between the sexes may push future research to determine why men show earlier cognitive impairment. Experts note that because evidence shows Alzheimer’s disease may cause changes in the brain one or two decades before the first symptoms appear, there is intense interest in investigating the earliest stages of cognitive decline.
Researchers at the Eunice Kennedy Shriver National Institute of Child Health And Human Development have found that exposure to lead - and cadmium - in childhood may delay the onset of puberty in young girls, with higher doses increasing the chance for later maturation. The researchers analyzed blood drawn from more than 700 girls ages 6 to 11. They found that girls with elevated levels of lead were 75 percent less likely to have key adolescent hormones at levels that indicate the beginning of puberty. In girls with elevated levels of both lead and cadmium, this pattern was even more pronounced. Scientists speculate that the heavy metals might suppress the ovary’s production of hormones that prepare a young girl’s body to ovulate for the first time.
For this NIH news update, I’m Craig Fritz
Balintfy: News updates are compiled from information at www.nih.gov/news. Coming up: childhood obesity and nanotechnology. But learning about learning is next.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
White Matter and Learning in the Brain
Balintfy: Welcome back. Our first feature is about the brain and where learning happens in the brain. Traditionally, neuroscientists who have studied learning and memory have focused their attention on processes between neurons – the main kind of brain cell. But new research demonstrates that we have more to learn about how we learn. Anahita Hamidi reports.
Hamidi: Dr. Douglas Fields is a neuroscientist at the Eunice Kennedy Shriver National Institute of Child and Health Development (NICHD). Research from his lab has shown that white matter may play a more important role in facilitating learning in the brain than may have previously been thought.
Fields: Brain is composed of two tissues: gray matter and white matter. Gray matter, most people have heard of—that's the surface layer of the brain where the neurons and synapses and dendrites are located—but the connections between neurons are made possible through wire-like axons, so this is the white matter region of the brain which is composed of millions of bundles of axons that connect neurons and gray matter together.
Hamidi: Traditionally, learning has primarily been understood to be a function of new connections made at synapses and the connections made between neurons depends on the pattern of neuronal firing, or as any neuroscientist will tell you, neurons that fire together, wire together.
Fields: And this goes to the fundamental mechanism of learning, which is that neurons that fire together, wire together. Pavlov's dog is a good example where the food had to be presented at the same time as the bell to have the neuron that controls saliva become conditioned to respond to the bell. Neurons that fire together wire together.
Hamidi: So the question still stands: what does white matter or myelin have to do with anything? Well, in order to help neurons fire together, impulses must arrive at the neuron at the same time. In large brains, the distance between neurons can be quite large and to help the neurons fire together, the speed of impulse must be increased.
Fields: And what controls the speed of impulse flow in the brain is myelin. Myelin can increase the speed of conduction a hundred fold.
Hamidi: Increasing the speed of conduction is important, of course, but it's ialso mportant to keep in mind that faster is not always better. What's more relevant, Dr. Fields explains, is the synchrony of neuronal firing.
Fields: So we now realize that it's important, especially in higher-level cognitive function that the speed of impulse transmission between different parts of the brain involved in a complex cognitive function, that that speed be synchronized and optimized, just like a train system has to be highly synchronized.
Hamidi: Neuroscientists interested in studying learning have used various techniques for investigation. One such technique, used to study the brains of humans non-invasively is brain imaging. At first, Dr. Fields explains, scientists focused all their attention, yet again, on gray matter—since this was where the bulk of neurons are located.
Fields: But it also became apparent, eventually, that there were changes in white matter regions of the brain. So it’s the new human brain imaging that has shown differences in white matter and originally, in terms of pathology, and differences in ability, for example learning to play the piano, is associated with increases in white matter in specific tracts of the brain associated with these mental processes that are involved in, for example, musical ability, finger coordination.
Hamidi: Dr. Fields’ own research has demonstrated on a cellular level that experience helps to drive changes in myelin which is further evidence that white matter is involved in learning.
Fields: Some of those glial cells that form myelin, were of particular interest and our work showed that when we made impulses, when we generated impulses in axons, myelin was increased.
Hamidi: All in all, it seems like neuroscientists are learning that white matter really does matter. For more information regarding the research from Dr. Fields’ lab visit http://nsdps.nichd.nih.gov/. This is Anahita Hamidi, National Institutes of Health, Bethesda, Maryland.
We Can! and National Childhood Obesity Awareness MonthBalintfy: September is not only back-to-school time, it also is National Childhood Obesity Awareness Month. With us today we have Karen Donato, Coordinator of Overweight and Obesity Research Applications in the Division for the Application of Research Discoveries at the National Heart, Lung, and Blood Institute. Ms. Donato also serves as the Coordinator for We Can! Ms. Donato, what exactly is We Can!?
Donato: We Can! stands for Ways to Enhance Children’s Activity & Nutrition, and it is science-based education program from the National Institutes of Health. And it has been really designed to give parents, caregivers, and even entire communities a way to help children 8 to 13 years old stay at a healthy weight. WeCan! has three key behavioral objectives: and those include eating right, increasing physical activity, and reducing screen time. And the program actually provide tools, tips, and resources to help parents and families deal with these behavior objectives.
Balintfy: You mention reducing screen time. Can you explain what that is?
Donato: Sure, reducing screen time means that a lot of children are spending excessive amounts of time in front of the television and video games. And we recommend that parents limit the time in front of a TV – or computer – to less than two hours a day.
Balintfy: OK. Why is awareness about childhood obesity crucial, especially now?
Donato: Well, we feel that awareness is really the first step in solving this problem of childhood obesity. The launch of the First Lady’s Let’s Move campaign actually has garnered more attention to the issue. September is marking National Childhood Obesity Awareness Month, and we really have an opportunity to reinforce the message that childhood obesity is a serious national problem.
We know from the statistics National Health and Nutrition Examination Surveys that over the past 30 years, prevalence of childhood obesity has more than doubled among children ages 2-5; it’s tripled among youth ages 6-11, and has more than tripled among adolescents and teens ages 12-19.
Currently, the latest data from 2007-2008, indicate that 17 percent of children ages 2-19 years are considered obese with an additional 15 percent are considered overweight. We also know that these children who are overweight or obese are at high risk of become obese as adults; and as obesity increases in adults, adults are at increased risk of heart disease, high blood pressure, type 2 diabetes, certain types of cancers and other really serious chronic conditions.
Balintfy: So even though the WeCan program focus on children 8-13, childhood obesity is something to start being aware of even earlier - a 2-5 year old can be obese?
Donato: Yes, we know that children ages 2-5 are at increased risk for obesity today. And we are also thinking about ways to help parents of children within that age bracket within the WeCan! to take the necessary steps to make sure that we prevent obesity in these kids while also allowing for adequate growth and development because that’s also key at those ages.
Balintfy: So what are some things parents do to help children lead healthier lives?
Donato: We’d like to provide parents with some ideas to think about ways to promote healthy choices not only for their children but for the whole family. And when you’re planning lunches not only for your children but for yourself – perhaps going off to work - there are some simple ideas that you could put healthy twists on things. One popular one is this inside-out sandwich where you actually use lettuce instead of bread. And you use the lettuce to wrap the turkey and the cheese and you make your sandwich out of that.
Another one is peanut butter and jelly: by using peanut butter on a whole-wheat tortilla and put a banana in there for fruit and fiber. It makes for quite a nice alternative for children.
It is also really important though, in addition to eating even right, that parents really begin to plan and schedule time for the whole family to become physically active. It’s recommended that children get at least 60 minutes of physical activity each and every day. And it’s also kind of difficult with parents with busy schedules to make sure that happens. So if they really plan for that activity, and put it on the calendar and make sure the family is being active together, it’s more likely to happen.
Balintfy: What is We Can! doing to mark National Childhood Obesity Awareness Month?
Donato: Well as you know We Can! has been around for about five years. We’ve grown as a national movement I think at this point into over than 1,300 community sites, from 14 which is what we started with. And to coincide with National Childhood Obesity Awareness Month, we want to really focus on the success that many of these community sites have had over the years in terms of what they’re doing at the local level.
So in order to commemorate their successes, we launched our first We Can! video contest where we asked community sites to give us videos of what’s going on in their communities. And they have highlighted our objectives—eating right, increasing physical activity, or decreasing screen time. We held a public vote on the We Can! Facebook page. And this was are really exciting opportunity for the community sites to showcase what they’re doing and to have actual public come into the YouTube and Facebook pages and vote for the most popular WeCan! video. And you can see all of that on our Facebook page at www.facebook.com/nihwecan.
Balintfy: I’ll go over those websites again. But is there anything that you think is worth reemphasizing?
Donato: Well, I’d like to also point out that WeCan! is a great collaboration of four institutes at NIH who really work together fabulously well in making sure that the public are getting consistent science-based messages on ways to help children prevent overweight and obesity.
Balintfy: Excellent, thank you very much.
Donato: You’re welcome.
Balintfy: That’s Karen Donato at the National Heart, Lung and Blood Institute. We Can! information can be found at the NHLBI Web site, at wecan.nhlbi.nih.gov, or by calling toll-free 1-866-35-WE-CAN. And don’t forget to check out the We Can! community site videos at www.facebook.com/nihwecan. Coming up next, nanotechnology and cancer.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Nanotechnology and Cancer - 1
Balintfy: An estimated 1.5 million adults were diagnosed with cancer in 2009, with more than 562,000 dying from it in that one year alone. About 11.4 million men and women alive today in the United States have been diagnosed with some form of cancer during their lifetimes. Those are some somber statistics, but mortality rates and incidence have decreased over the last decade and more people are surviving the disease; and now, nanotechnology is poised to further advance this progress through improved screening, diagnosis, monitoring and treatment of cancer.
We’re kicking off a series of interviews about nanotechnology and cancer. In this first, Calvin Jackson talks with Dr. Anna Barker, Deputy Director at the National Cancer Institute. They discuss where nanotechnology is since the launch of the Alliance for Nanotechnology five years ago. Calvin starts by asking what is nanotechnology and how can it be used to combat cancer?
Barker: So nanotechnology is a fairly simple concept: It’s a micro machine basically. And to put it in real perspective, a human hair—a nanometer’s about 50 thousand times smaller than that. So we’re talking at the range of 10 nanometers up to say a thousand nanometers as being, sort of, the range that we think about when we talk about nanotechnology. So, the thing about nanotechnology that’s really interesting, is that nanotechnology really employs functionality. So not only is it small, it’s functional.
And when it comes to cancer, this is a way to get things very specifically into cancer cells, and a way to understand how cancer evolves and develops in cells. And so it’s a very powerful technology for cancer.
Jackson: And I would imagine that using the nanotechnology to combat cancer would be much more efficient than traditional methods we have now such as chemotherapy or radiation, which destroy even healthy cells.
Barker: Yeah and that’s a very interesting question because one of the earliest applications for nanotechnology has been to take drugs that are already on the market—and by putting them in a new construct, a new nanotechnology delivery vehicle—where some of those drugs are actually performing much better. Why is that? Because you’re delivering the drug more directly to the cancer cell, you’re sparing the normal cells.
So, I mean, it’s a very interesting time right now because people are starting to think about this technology not just to build new drugs, but also to better utilize the drugs that we have. I think it’s a win-win.
Jackson: So, now why is collaboration among scientists so critical to nanotechnology and cancer research?
Barker: At a level where you get down below, say, a hundred nanometers, the size and shape and charge all those things are studied by physicists and predicted by mathematicians.
When you think about the behavior of cells and how they actually migrate in a body and what they do, that actually has been the domain of biologists.
So what happens in nanotechnology is those areas have to come together. So the physicists, the biologists, the mathematicians, the engineers, chemists, all have to come together to understand how do these tiny particles—and they’re very multifunctional sometimes—how do they behave, how can we make them behave the way we want them to behave by functionalizing them.
So now all of a sudden it requires entirely new teams of people and the Nanotechnology Alliance for Cancer in its first five years has brought together some unbelievably powerful teams of physicists, mathematicians, cancer biologists, oncologists even, people treating, taking care of patients in the clinics. So it requires a new sort of approach to science which is in the first five years of Nanotechnology Alliance for Cancer, we very effectively have done that by bringing some very unique teams together.
Jackson: Speaking of the alliance, I understand the NCI has just recently decided to continue to invest in the program for another five years. What is NCI’s goal for nanotechnology over this time period?
Barker: When we started the alliance, we had a lot of goals, I mean, as you always do for programs like this. This was the largest initiative ever undertaken in medical nanotechnology. This is medical nanotechnology. There is a National Nanotechnology Initiative which we’re part of, but this is focused on medical nanotechnology, specifically cancer.
So how have we done in five years? Well, we’ve done pretty well.
In these first five years we’ve developed a field, we’ve got a lot of new agents coming out of the alliance already in clinical trials and we have many in the pipeline coming into clinical trials. So by putting the patients at the center and saying we want you to transfer your technology has been very effective.
So, we decided to give this program another five years because we really want to see this science really translate into patients in the next five years. And so that’s the focus for the next five years: translate, translate, translate.
Jackson: You sort have answered my next question. I know it’s always hard to predict what’s going to happen in research, but what Alliance for Nanotechnology breakthroughs can we expect in the future?
Barker: Well I think it’s always hard to predict the future, but we can at least go with the present in terms of what we know is going on from alliance investigators. For example, we have breakthroughs that I think are going to be coming fairly quickly in imaging.
Nanotechnology is used pretty effectively to improve and enhance imaging. For example, Dr. Ralph Wislider at Harvard has actually created a new nanoparticle that is able to detect as few as two cancer cells in one microliter of biospecimens and that’s patient materials. And that’s pretty amazing because that means you’ll be able to with imaging to look at exactly what you’re delivering to cells.
We have a lot of things going on at early detections so I would predict that in the next five years we are going to see a lot of progress in terms of new technologies to detect cancer very early and actually detect its recurrence very early.
In terms of drug development, I think the earliest winds, which are already occurring in nanotechnology, are in delivery of drugs. Well it turns out that one of our—Dr. Mark Davis actually—one of our investigators in the alliance is actually able to deliver RNAI in a nanoparticle and it’s never been done before. I mean ranging all the way from established drugs to very new drugs, I think you’ll be able to see some real advances in the way we deliver drugs to patients.
Then last, there are some of the alliance investigators that are actually putting together combinations of diagnostics and drugs.
So I think you’re going to see real progress in this area of very complex constructs that can detect disease, deliver drug, monitor patients.
Jackson: I just have one final question for you. And again, this is an open ended question, but how much longer before we begin to see nanotechnology being commonly used in the clinic to diagnose, treat, and maybe even prevent cancer?
Barker: Well it’s a very interesting question because although people aren’t thinking much about it, we already use nanotechnology in the clinic pretty broadly. This isn’t a new chapter for us.
What you will see though, I think, is see these new constructs coming forward that are either entirely new particles that are actually things like Mark Davis’s particle, for example, delivering something like RNAI to patients. But I think in the next five years, the most progress may occur in early diagnosis. Right behind that is going to be these very combined—these very complex, combined constructs. These combinations of diagnostics and therapeutics—this about the only way we can do this. So I think nanotechnology is going to be a leader in that area. It’s a longer time frame but I think in five years, you’re going to see real progress in that area.
But we don’t want to over promise, but by the same token we want to make sure that we’re communicating about it regularly because we are doing everything we can to make sure that these approaches are safe for patients, but also that if they’re better for patients they get to patients as effectively and as efficiently as we possibly can. So we’ll continue to push our investigators to translate the science to patients.
Balintfy: That was Dr. Anna Barker at NCI speaking with Calvin Jackson. For more about nanotechnology and cancer, visit www.cancer.gov. Also, be sure to tune in to future episodes as this series on nanotechnology continues. For now, that’s it for this episode of NIH Research Radio. Please join us again on Friday, September 24th when our next edition will be available. I'm your host, Joe Balintfy. Thanks for listening.
Announcer: 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.