December 16, 2011
NIH Podcast Episode #0149
Balintfy: Welcome to the episode 149 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, which is our last of the year by the way: the risk of cancer in people who receive organ transplants, certain cells that super-size our guts, finding out about your family health history during the holidays, and our continuing series on women in science. But first, this news update. Here’s Craig Fritz.
Fritz: Cigarette and alcohol use by 8th, 10th and 12th-graders are at their lowest point since NIH’s Monitoring the Future survey began polling teenagers in 1975. However, this positive news is tempered by a slowing rate of decline in teen smoking as well as continued high rates of abuse of other tobacco products such as hookahs, small cigars, and smokeless tobacco. Additionally, the use of marijuana and prescription drugs continues to be high. The survey results show that more teens continue to abuse marijuana than cigarettes; and alcohol is still the drug of choice among all three age groups. Monitoring the Future is an annual survey and was conducted in classrooms earlier this year.
An NIH health network analysis of 5 previous studies has uncovered additional evidence of the effectiveness of progesterone in reducing the rate of preterm birth among a high-risk category of women. Progesterone is a naturally occurring hormone. Pregnant women in this category have a short cervix, and are at increased risk of delivering early. Preterm infants born 3 weeks or more before a full 40-week term, are at increased risk for death, breathing difficulties, cerebral palsy, learning disabilities, blindness and deafness. The current study used a statistical technique that combines the data from several similar studies. The researchers found that progesterone reduced preterm delivery before week 28 by half, a substantial reduction in risk.
For this NIH news update – I’m Craig Fritz
Balintfy: Thanks Craig. News updates are compiled from information at www.nih.gov/news. Coming up stories to make you think about your holiday eating, and about considering a career in science. Also, organ transplant recipients’ cancer risk. That’s next on NIH Research Radio.
Happy Holidays from all of us at NIH Research Radio! An important end of year program note for you: We’re skipping an episode for the year-end holidays. Our Friday, December 30th episode, number 150, will be available on Friday, January 13th of 2012. We’ll return to our every-other-Friday schedule then so be sure to keep tuning in starting January 13th. Thanks for listening and Happy Holidays again from all of us at NIH Research Radio!
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NIH study finds broad spectrum of cancer risk for organ transplant recipients in US
Balintfy: People who receive organ transplant in the United States are at risk of developing 32 different types of cancer. Wally Akinso has this report.
Akinso: According to an NIH, study, organ transplant recipients in the US have a high risk of developing cancer.
Engels: We looked at about 50 different cancers in the study. And we found that transplant recipients had an increase risk for 32 types of cancer.
Akinso: NIH researcher Dr. Eric A. Engels is the lead author of the study.
Engels: There were 175,000 transplant recipients included in this study. We were able to include that many people because we collected data from large national and state data bases called registries.
Akinso: In 2010, over 28,000 transplants were performed in the US. Dr. Engels explains why transplant recipients may be at a high risk of developing cancer.
Engels: The major reason why transplant recipients have an increase risk of cancer is because their immune system is weakened.
Akinso: It has been well documented that transplant recipients are at a higher risk for developing cancer than the general population. But past studies of cancer risk in transplant recipients focused mainly on those who received kidney transplants, and other studies were too small to accurately estimate risk for all but the most common cancer types. Dr. Engels says this current study is much larger than prior studies.
Engels: And we included a very representative sample of the U.S. transplant population. So we had recipients of all of the major types of transplant organs, whereas some of the previous studies only included kidney recipients. So our study was larger and more representative and we can get a better picture of the cancer risk.
Akinso: Researchers carried out additional analyses on four cancers based on known risk and their new study.
Engels: The most common of these was non-Hodgkin lymphoma which is a cancer of the immune system. We saw an increase risk of lung cancer. We're not exactly sure why all those lung cancers are developing. A big part of that is smoking and the risk was most common among lung recipients who have damage lungs. We saw an increase risk of liver cancer that was really restricted to liver recipients. And we think part of the risk is related to hepatitis virus infections particularly hepatitis C. And then finally we saw an increase risk of kidney cancer.
Akinso: Dr. Engels hopes that the findings will stimulate other research dealing with cancer risk associated with organ transplantation. For more information, visit www.cancer.gov. This is Wally Akinso at the NIH, Bethesda, Maryland.
Intestinal stem cells respond to food by supersizing the gut
Balintfy: You know many organs basically rebuild themselves many times over through our lives. In the case of our gut or intestine, we get a completely new one every three to five days. An NIH-funded study at the University of California, Berkeley, is showing that intestinal stem cells can also reshape the gut in response to food. The the current understanding of how stem cells work is that once they mature into adult stem cells, they simply replace cells that die or are injured. But that thinking is changing.
O'Brien: So what our team has found out is that the stem cells can do more than just maintain organs. They can actually cause organs to grow.
Balintfy: That's Lucy O'Brien, an assistant researcher in the lab of Professor David Bilder at UC Berkeley. She says this finding could have implications for diabetes and obesity. Before we get too far into those findings, what exactly are stem cells?
O’Brien: When most people hear the words "stem cell," they often think of embryonic stem cells, special stem cells that come from embryos that are able to make an entirely new animal. But it turns out that there is another whole category of stem cells and these are the adult stem cells. These adult stem cells are living in all of our bodies right now, and in fact, they're the reason that when we get up in the morning we look pretty much the way we did the day before. These adult stem cells are doing the daily maintenance of almost all the tissues in our body - our skin, our blood, our lungs, and our intestine.
Balintfy: Through NIH funded research with fruit flies, O’Brien and her research team have found that intestinal stem cells respond to increased food intake by making more intestinal cells.
O'Brien: What we found is that in flies, intestinal stem cells cause the intestine to grow when the animal eats. So the trigger for intestinal growth is feeding. When a fly eats a meal like a rotten banana and this banana arrives in the intestine, the intestinal stem cells sense this. They start to divide and divide and divide. They go into overdrive and they make extra intestinal cells which get added into the intestine and make a bigger organ.
Balintfy: She adds that a fly that has been eating has four times more cells in its intestine than a fly that hasn't been feeding; without food, the stem cells shut off, and over time the intestine will shrink back down. O'Brien says this research could have implications for obesity and diabetes.
O'Brien: These are diseases that often involve problems with insulin regulation, and it turns out that the way that fly intestinal stem cells go into growth-activating overdrive is through an insulin signal. When they fly eats and food arrives in the intestine, the intestine itself secretes insulin and its intestinal insulin talk to the stem cells and tells them that it's time to activate growth.
Balintfy: She also points out that it wasn't just the intestinal cells that were activated to grow.
O'Brien: And this was very surprising to us when we found this out -- when the stem cells are causing growth, not only are they making more intestinal cells but they're actually also at the same time making more of themselves. So they're increasing their own numbers.
Balintfy: Though working with fruit flies and intestinal stem cells, O'Brien says these findings may also have implications for other tissues as well, for example blood and mammary glands.
O'Brien: I think by expanding our view of what stem cells are capable of, it gives us more ideas about how we can harness the potential stem cells and apply them to human disease.
Balintfy: O'Brien and Bilder are coauthors on a paper in the journal Cell. For more information on this research, visit www.nigms.nih.gov.
Discussing your family health history during family holiday gatherings
Balintfy: From fruit flies to fruit cake. Family get-togethers during the holiday season are good times to discuss family health history. Knowing your family health history can help prevent serious health problems. Even though the month of December can be especially busy, and full of occasions to eat fruit cake and other goodies, it can also be an opportunity to focus on health.
Rodgers: Winter is a season of holiday celebrations and a time when families often get together to enjoy their traditions and festivities
Balintfy: Dr. Griffin Rodgers is an institute director at the NIH. He says the holiday season is an important opportunity for families to take time to talk about and even write down their family health history.
Rodgers: Many serious diseases, such as diabetes and kidney disease, as well as being overweight or obese, run in families. And knowing your family's health history is important to help you understand your chances of developing health problems.
Balintfy: Nearly 26 million Americans have diabetes and of those, 7 million don't know they have the disease. Having a family history of diabetes, is a risk factor for developing the disease. But Dr. Rodgers points out that while a family history of diabetes can't be changed, there are things that can make a difference.
Rodgers: For instance, if you have a family member with diabetes or kidney disease – such as a mother, father, brother, or sister – talk to your family health care team about making a plan to maintain a healthy weight or lose some weight if you are overweight, as well how you can make healthy food choices and be more physically active each day. Doing so can help delay or prevent diseases like type 2 diabetes which can lead to serious health problems such as blindness, amputation, kidney disease, heart disease and stroke.
Balintfy: Dr. Rodgers adds that in addition to making a year-round plan, there are tips for this time of year.
Rodgers: As you push to fulfill the demands of the hectic holiday season, make sure you carve out time to move more and make healthy food choices, and here's a few tips: Eat a healthy snack before a big event to prevent overeating at the party or gathering. Focus on family, friends and activity instead of the food that's there at the gathering. Stay active. Encourage your family and friends to take walks, dance and play games. These are all fun events.
Balintfy: Dr. Rodgers points out that saving up for a big meal may actually do more harm than good.
Rodgers: If you sort of decide early in the morning that I'm not going to eat at all today, because there's this big celebration tonight, you probably in terms of amount of daily calories you take in, end up taking in much, much more because you justify in your own mind, you know, I haven't eaten all day and so. So if one eats normally and potentially has a snack right before, you'll enjoy the time with your family as you eat more modest numbers of calories.
Balintfy: Other tips he recommends include planning ahead by preparing or bringing a food that fits into your meal plan. Also, watch the alcohol – that can be a major source of hidden calories. Water is a healthy, no-calorie beverage. For more information and tips on having a healthy holiday, as well as understanding the importance of learning about family health history, visit www.niddk.nih.gov.
And coming up, why become a scientist or researcher? We’ll get a personal perspective. That’s next on NIH Research Radio.
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Women in Science
Balintfy: Back in episode 144 of NIH Research Radio, we had the first of an occasional series on women in science. Sarah Rhodes is a Ph.D research fellow at the National Institute of Mental Health and a member of the NIH Women Scientist Advisors Committee. She brings us this interview with Dr. Judith Walters.
Rhodes: Dr. Judith Walters is a senior Investigator in the Experimental Therapeutics Branch at the National Institute of Neurological Disorders and Stroke here at NIH. She has been selected to give one of the 2 esteemed NIH Anita Roberts Lectures in 2012. These lectures are organized by the NIH Women Scientist Advisors Committee and serve to highlight the outstanding research conducted by female scientists here at NIH. We are lucky to have Judy here with us today to talk a little about the personal story behind her career success. Thanks for joining us Judy.
Walters: Thank you.
Rhodes: Could you tell us a little bit about your research?
Walters: Well, since my graduate school days I have been interested in the role of dopamine, the neurotransmitter dopamine in the central nervous system. The dopamine system is really fun to study because it's relevant to so much of our interesting behavior -- attention and reward and movement and then there's addiction and schizophrenia and ADHD and Parkinson's disease, which is our major focus.
Rhodes: And why did you decide to become a scientist? Did you ever consider doing anything else?
Walters: When I think about this question I think about my childhood and I spent the summers from the time I was three until I was about 14 in a boys' camp in the mountains of New Hampshire. My father was the director of the boys' camp and there really weren’t any other little girls around to play with. So I had a lot of time in my hands and I read a lot, but I really got interested in nature. And my father was an avid fisherman and I was the one of the siblings that he took fishing. I think I realized a girl could do these things -- a girl could bait a hook, a girl could fish. I felt confident in that area and that sort of carried on. I went to science camp when I was in high school and a wonderful college, Mount Holyoke College for women where there were many women mentors who were very accomplished scientists. The message was even in those days where women weren’t doing much by way of going into scientific careers at least in the '60s, they were starting to, but it was okay to be a woman and to do this. And I love the brain. So how the brain works was always a fascination to me.
Rhodes: Moving on to more personal aspects. How has your research career impacted on your personal life and vice versa or how have you managed to sort of maintain this balance between work and family?
Walters: Well, I have three sons and I'm here to say it's hard to find the balance --
Rhodes: Just having three sons?
Walters: No. Well, the three sons are great, but the balance is tough. When I had my children, in some ways it may have been easier because there were fewer women trying to do this, trying to manage infant care and full-time work, and so there were perhaps more people on the market available to help you. But on the other hand, now there are more institutions and organizations that are prepared to help women in this situation, but it's always hard.
I had my first son and I went back to work after two weeks because I had said I would and I had no idea how hard it was going to be. Every young mother will say it's much more wrenching than you think it's going to be. So after my second son, I said I'm going to work part-time -- or actually before I had my second son. I'm going to work part-time for a while. Then I realized that I would probably be working just as hard and only earning less money. But I do think the balance is very difficult.
Being at NIH was a big help because you could focus on research as opposed to being in an academic situation where you may also be required to teach. But it's not easy. I think we need to support women in trying to do this. Now, it's quite simple too because my sons are grown up and I think they're happy to have a researcher mother, but it's been a challenge.
Rhodes: So as a woman in science, can you comment on the advantages and disadvantages?
Walters: Well, I think for me personally, because of the age that I was at the time when the Women's Movement began, it has in some ways been an advantage to be a woman although overall I think there are certainly many obstacles when you're trying to forge a career in a heavily male-dominated field. But in my personal experience, I came into the workforce at a time when institutions were beginning to think "Oh, well, maybe we should hire a woman or two."
I had the model of the women in my all women's college, the women scientists there. I had those models to follow. But I was certainly aware that I was expected to live up to the male standards of behavior which was probably why I felt compelled to go back to work after a couple of weeks of having my first child.
It's always been a bit of a challenge, but I think women have come a long way since I started. I was the first woman -- oh, when I went to Yale, pharmacology department, one woman had graduated and a couple of others came along after that. Behind me it was 50/50 practically in that department.
So I feel I was right at the cusp of women coming into science as kind of a normal thing not an extraordinary thing, and it's been a very interesting time to live through. In that respect, I'm sorry, I haven’t had any daughters to pass this on with, but I try to make up for it by talking to my postdocs.
Rhodes: Do you believe that mentoring is important for young scientists and especially young female scientists?
Walters: Absolutely. I tank it's important to have a mentor who is interested, who is supportive, who helps guide your career, shares your excitement and passion for science. That's certainly critical.
Rhodes: What advice would you give a young scientist who is thinking about entering science?
Walters: Two thinks come to mind. First, if you're passionate about trying to find out how things work, if you find science fascinating, go for it. I think it's the satisfaction, the addressing your curiosity about how things work that's so important. And the other thing I think is start early. Read and see if you can get an internship somewhere. I have a couple of high school students working in my lab. Try to find experiences that will give you some insight into certain areas of science that are interesting to you.
I think it's too bad that they don’t teach in high school what drugs do to the brain. I think more neuroscience needs to be taught at all levels. Of course, I'm sure people would find it fascinating, and then we would have a bigger cadre of young people interested and educated about these things which would be a very good thing.
Rhodes: Well, thanks ever so much, Judith, for taking time out of your incredibly busy life to join us today.
Balintfy: That was Sarah Rhodes talking with Dr. Judith Walters at NINDS. Dr. Walters is scheduled to speak at the NIH Anita Roberts Lecture on Thursday, April 5 in 2012. You can find out more about the lecture series organized by the NIH Women Scientist Advisors Committee at the website sigs.nih.gov/wsa
Balintfy: And that’s it for this episode of NIH Research Radio. Please join us again on Friday, January 13 – remember, we’re skipping an episode for the year-end holidays. So our next edition will be available a month from now. If you have any questions or comments about this program, or have story suggestions for any future episodes next year, please let me know. Send me email—my address is email@example.com. I'm your host, Joe Balintfy Thanks for listening and have a very happy holiday and healthy New Year.
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