Appetite and Attitude
Carbohydrates may cure a bad mood, says Judith Wurtman
By Mara E. Vatz
Its mid-afternoon. youre tired, cranky, and a little stressed. You reach for a cookie or some candy from the vending machine, and 30 minutes later, you feel a little better. Some might call this self-indulgence, but Judith Wurtman calls it self-medication.
Wurtman, a visiting scientist and director of the Program in Womens Health at the MIT Clinical Research Center (CRC), maintains that carbohydrate cravings are not only about meeting nutrient needs. She says eating carbohydrates can improve a persons mood and, in the right amounts, actually help regulate appetitea suggestion that may come as a surprise (or a relief) to people on popular low-carbohydrate/high-protein diets.
In studies she conducted with her husband in the late 1980s and early 1990s, Wurtman found that carbohydrate consumption can help women suffering from premenstrual syndrome, offering subtle improvements in their mood and ability to concentrate. Now, Wurtman is studying whether eating carbohydrates can help people suffering from seasonal affective disorder, a condition that leaves them feeling blue in the winter months.
Nutritional Science Pioneers
Wurtman and her husband, Richard Wurtman, who is director of the CRC, began studying carbohydrates more than 25 years ago, when research on factors that control eating behavior was scarce. In the early 1970s, Richard Wurtman was studying the synthesis of serotonina neurotransmitter that regulates mood, sleep, and appetite. He found that when a person eats carbohydrates, an amino acid called tryptophan is brought to the brain, which stimulates serotonin production. Serotonin, in turn, regulates carbohydrate intake: when serotonin levels are high enough, cravings for carbohydrates subside, while protein cravings go up.
When Richard made this discovery, it was like a little crack opened in the door, Wurtman says. We wondered together whether there might be a specific appetite for carbohydrates, and whether that might account for certain groups of people who are obese.
By the late 1970s, Wurtman had joined her husband at MIT to conduct a series of studies at the CRC. The pair observed the eating and behavioral patterns of volunteer patients, and over the next two decades, they found several examples of the connection between mood and carbohydrates. In one study, they discovered that women who suffer from mild to moderate premenstrual syndrome could alleviate their symptoms by eating carbohydrates. In the late 1990s, Wurtman developed a carbohydrate-rich drink called Serotrim, which contains a mix of carbohydratessome that the body quickly digests, and others that take it longer to digest. The drink is used as part of a weight-loss program to help boost serotonin levels and curb cravings.
Wurtman, who cofounded the Boston-based Adara weight-loss center in 2002, says serotonin is natures way of controlling how much we eat. It makes you feel fullnot in your stomach so much, but in your head, she says. Although carbohydrates have long been vilified for causing weight gain, Wurtman says that heeding carbohydrate cravings is just as important as heeding a craving for water. But its important to eat the right kinds of carbohydrates. When you have a carbohydrate craving, theres nothing that says you have to satisfy it with french fries or doughnuts, she says. Satisfy it with a potato, or satisfy it with brown rice.
Janine McDermott, who has worked with Wurtman both as associate director of the Program in Womens Health and as an Adara program manager, says people tend to be drawn to low-carb/high-protein diets because they show quick results. But she warns that those results may not be long lasting. People have this feeling that when youre dieting you cant be eating, she says. Wurtmans philosophy is unique in that her diet plans are trying to keep you stable and satiated throughout the day, McDermott says.
The Nutritional Frontier
In collaboration with David Mischoulon, a psychiatrist from Massachusetts General Hospital, Wurtman is now studying whether a dose of carbohydrates can help treat people with seasonal affective disorder. We want to see whether increasing serotonin with a dietary interventioncarbohydrateshas a beneficial effect on cravings and mood, she says.
She is also coauthoring a book on nutrition based on her recent clinical research and on weight-loss programs at Adara. The book is aimed at people who find they cant control their eating when they complete a low-carb/high-protein diet, people who overeat as a reaction to emotional stress, and people who have gained weight while on antidepressants. Other diets are based on things like blood sugar or on eliminating toxins, or eliminating entire categories of foods, and our diet is none of those, says Nina Marquis, Adaras medical director and Wurtmans writing partner. Its more about the timing of the foods you eat to optimize your brain chemistry.
For people who have failed on a diet because they felt unsatisfied and irritable, Wurtmans findings could help them lose weight and counteract emotional triggers at the same time.
Patches for the Perfect Pump
Mending broken hearts
By Stu Hutson
For durability, its hard to match human heart muscle. The hearts muscle tissue takes wear and tear well enough to circulate 200 million liters of blood in 80 years. That is, unless a blockage deprives the tissue of oxygen, killing part of the perfect pumping machine with potentially fatal results for its owner. Now, researchers from MIT and Harvard Medical School have taken a first step toward creating patches for dead heart tissue. Eventually, they hope to be able to grow patches from patients own cells.
The scientists reported that they grew pieces of living, beating heart tissue from a few cells culled from rats. Our ultimate idea is to be able to build a patch that could replace damaged tissue and keep the mechanism working, says Gordana Vunjak-Novakovic, a researcher in the Harvard-MIT Division of Health Sciences and Technology who worked on the project with postdoc Milica Radisic, the papers lead author.
The patent-pending process involves growing rat heart tissue on a scaffold of collagen, a fibrous protein. After the researchers cover the structure with rat cells, they immerse it in a bath of nutrients. The scaffold slowly disintegrates as the heart cells begin to form connections, taking on a structure of their own.
One of the teams most significant discoveries is that the developing cells are erratic and uncoördinated unless coached by an electric shock. In an embryo, nascent heart cells begin to contract when shocked periodically by the bodys pacemaker, the sinoatrial node. Over time, the contractions become more coördinated, and the heart is able to pump blood effectively. The team replicated sinoatrial-node pulses by using a pacemaker. After eight days of preparation, their collection of cells developed into a solid piece of twitching tissue.
The researchers are now trying to determine how to effectively transplant these pieces of tissue into host rats. Human tissue patches are also in the works. The team has been attempting to build human patches using adult stem cells for more than a year, and they began using embryonic stem cells at the end of last year. Their ultimate goal is to build patches from a patients own cells, so that the repair tissue will always be compatible with the patients immune system and wont carry diseases the patient doesnt already have.
Another application might pop up before then. For example, the tissue samples may provide an ideal way to pretest new heart medications, says Frederick Schoen, a Harvard University professor of pathology who participated in the study. One of the commonly overlooked benefits of this type of tissue engineering is that it will allow us to screen on a lab bench what could be too expensive or dangerous to screen in the human body, he says.
MIT dancers experiment with off-balance choreography
By Catherine Nichols
During the independent Activities Period (IAP) in January, MITs Kinaesthetics Lab was issued a four-day mechanical-engineering challenge. It wasnt to design a solar-powered car or a remote-controlled robot, however, but to build a swaying dance platform. The Kinaesthetics Lab, you see, is a student choreography group. The challenge came as Paula Josa-Jones, a Boston-based choreographer, and Ellen Sebring, SM 86, a research associate in MITs Visualizing Cultures project, worked with the students to choreograph a dance based on the concepts of altered gravity and lost balance.
Josa-Jones began to conceive the project in the early spring of 2001. She asked Sebring to join her in filming two dancers walking along the sea wall near her Marthas Vineyard home. The camera circled around the dancers, creating the illusion that the ground itself was swaying. Following the events of September 11, 2001, their work seemed well timed to reflect the internal turbulence that the nation was experiencing. The film was later shown at the 2004 Dance on Camera Festival in New York City.
During IAP, Josa-Jones and Sebring wanted to take their project a step further and literally make dancers lose their balance. The artists and the Kinaesthetics Lab students explored the mechanical aspects of balance as well as the artistic challenges of blending video with live dance. Their work culminated in a performance on January 22.
At the performance, two women danced on the platform, which was rocked by the Kinaesthetics students, as Sebring and Josa-Joness video played behind them. The dancers movements were dreamlike as they swayed with and against the gyrations of the platform. Only their tense ankle muscles and hasty foot placement revealed how difficult it was for them to maintain their balance.
Sebring says she was pleased with the performance, and particularly with the beauty in the Atlas role of the [platform] movers, wonderfully performed by the MIT students, who shifted the mechanism and thereby the dancers world. Their success has made the workshop a launching point for further projects, Sebring says. She imagines using a broader swatch of stage in the future, for example, creating a sense of walking through air.
Computer models may reveal the protein collagens role in disease
By Stu Hudson
Assistant professor collin Stultz is taking a bottom-up approach to understanding diseases such as arthritis, cancer, and heart disease. A researcher in electrical engineering and computer science and health sciences and technology, Stultz has trained his sights on a protein best known as an ingredient in beauty products: collagen.
All three diseases involve enzymes that break down collagen, which provides the scaffolding for our skin, cartilage, bone, and connective tissue. For example, some tumors expel enzymes that destroy surrounding tissue, freeing malignant cells to spread. Right now, little is known about how these enzymes interact with collagen at the molecular level. But Stultz may have found the key to a deeper understanding. He has created a new computer model of collagen that might reveal its Achilles heel.
When Stultz began his work almost five years ago, computer simulations showed only how collagen looked in the crystalline state of samples prepared for x-ray diffraction, an imaging method used to determine protein structures. After examining the amino acid chains that make up collagen, Stultz guessed that the winding, kinked protein partially unfolds at higher temperatures or in the presence of other molecules in the bodyrevealing a part of its anatomy that is vulnerable to enzymes that can degrade it.
To explore this conjecture, he constructed a computer model of the unfolded protein and used it to estimate the readings that the protein would give when subjected to certain spectroscopic techniques. He tested these predictions experimentally and found that the data closely matched his model. Stultz achieved a working model of collagen last fall.
Stultz and his team hope that by further refining the model to reflect collagens reactions to specific diseases, they can discover how to maintain the proteins integrity, thus staving off the progression of arthritis, cancer, and heart disease.
Testing the Waters
An MIT robot maps the chemical composition of local lakes
By Mara E. Vatz
On a typical spring afternoon on the Mystic Lakes in Medford, MA, the only disturbance in the water comes from darting sailboats. But this spring, there is excitement below the surface. A group of MIT scientists is using an autonomous underwater vehicle to create a three-dimensional map of the lakes chemical composition.
Researchers from MIT Sea Grants Autonomous Underwater Vehicle (AUV) Laboratory have joined forces with the Parsons water resources lab in the Department of Civil and Environmental Engineering to develop a chemical-sensing network that will monitor the generation, transport, and ultimate fate of the environmental chemicals in the lakesand particularly of methane. A greenhouse gas, methane is a by-product of bacteria that feed on algae and zoöplankton. The Mystic Lakes are particularly methane rich, says Harold Hemond, one of the projects principal investigators. Hemond says this is because of all the fertilizer and nutrient runoff from suburban lawns and former industrial sites in the Mystic watershed. Nutrients get into the lake, and they promote lots of algae growth, he says.
One way to study the methane cycle in the water is to create a three-dimensional picture of how chemical concentrations change over time. Gathering this data, however, is usually a labor-intensive and inefficient process. Geochemists in the past have measured methane by going out in a boat, collecting samples, and taking them back to the lab, says Hemond. If they happened to find a chemically interesting area, he says, they wouldnt know it until they viewed the data in the lab. But now, using the AUV Labs chemical-sensing network, scientists stationed on shore will be able to collect and view data in real time and make on-the-spot decisions about where to take more measurements.
The network consists of a shore station, an array of buoys, and a 2.2-meter-long, teardrop-shaped robot, called Xanthos, equipped with a mass spectrometer to measure chemical concentrations. Essentially, were putting a giant nose in the water and having it go swim around and sniff things, says Rob Damus, an AUV Lab research engineer. While the robot is underwater, it transmits data to the buoys using acoustic signals. The buoys then use radio signals to relay the data to scientists on shore, who can then steer the robot toward areas of interest. If the robot finds an unexpected concentration of methane, for example, the scientists can send it instructions to investigate the area further.
Eventually, the researchers would like to enable the robot to make search decisions on its own. But that would mean endowing it with a certain amount of artificial intelligence, Damus says, and were nowhere near that. For now, the AUV Lab is testing just the basic system. Those tests will begin this spring and continue into the summer.
Further down the road, other projects, such as monitoring drinking water reservoirs or tracking sources of pollutants, may also benefit from deploying the system. The bottom line is, any time there is a chemical released into a natural water system, you come back to the need for a three-dimensional picture, says Hemond. And that is something that has been, until now, unattainable.
Can magnets help protect astronauts?
By Mara E. Vatz
Researchers in mits aeronautics/astronautics and physics departments are developing a new way to protect astronauts from cosmic radiation by adapting an age-old mechanism: the magnetic shield. The earths magnetic field has protected the planet from cosmic rays for billions of years; but according to former astronaut Jeffrey Hoffman, one of the projects lead researchers, scientists have only recently developed the superconducting magnetic technology necessary to replicate its protective effects.
Now, Hoffman is studying whether this technology can be made light enough to be launched into space. A magnetic shielding system will require a significant additional load of electrical, cooling, and structural apparatus and may turn out to be just as heavy as a system that blocks cosmic rays with thick layers of aluminum. If the masses turn out to be similar, then theres no point going to the trouble of building a complex magnetic system, says Hoffman. But preliminary calculations done by other researchers are promising.
The research, made possible by funding from the NASA Institute for Advanced Concepts, wont be put into use until astronauts travel farther from the earth than they have yet done. Short trips to the moon, for example, dont usually pose real radiation risks, says Hoffman. Its during eventual trips to Marsand beyondthat you really have to start worrying about radiation protection. Thats because a single solar flare can dish out a lethal dose of radiation, and theres also a possibility that chronic exposure to nonlethal radiation doses could shorten crew members life spans. However, if magnetic shields are ever put into use, Hoffman says, they would really enable people to go into regions where theyve never gone before.
Cambridge and MIT settle tax payment plan
By Sally Atwood
You can always count on death and taxes, but the city of Cambridge was not certain it could count on collecting taxes on MITs commercial properties forever. So in January 2001, the city asked MIT to enter into a binding agreement that would specify what taxes the Institute would pay if it converted commercial property into tax-exempt academic space. Just as President Charles M. Vest HM was stepping down last December, the city and the Institute together announced an agreement that places an annual cap on the amount of commercial property the Institute can remove from the city tax rolls. It also increases MITs voluntary payment in lieu of taxes from $1.2 million in fiscal year 2004 to $1.5 million in 2005 and stipulates a further 2.5 percent annual increase for the life of the 40-year agreement.
MIT owns 241 acres within the city, or 5.29 percent of the citys total land area. Of that property, 157 acres are tax exempt, but MIT is still the single largest taxpayer in Cambridge. In 2004 MIT paid $23.5 million in property taxes.
Under the new agreement, the property that MIT removes from the tax rolls in a given year must account for no more than .5 percent of the citys total tax levy. MIT will also phase out its property tax payments over three years to help the city adjust to the lost revenue. Over the life of the agreement, MIT can remove only 2.5 percent of the citys total tax levy from the rolls. If it exceeds that limit, it will pay full property taxes on the overage for 40 years from the year the conversion is made.
We have to keep pace with science, so we needed some flexibility that will allow us to convert property without being penalized all the time, says Sarah Gallop, codirector of MITs Office of Government and Community Relations. Cambridge, in turn, gains revenue protection and long-term predictability for its budgeting process.
MIT student prize winner develops stroke and cancer treatments
By Lisa Scanlon
At 27, david Berry 00 already has an impressive range of inventions to his credit: a novel protein for treating strokes, two new ways to attack cancer, and a method for enlisting bacteria to produce hydrogen. Thats why the MD/PhD candidate in the Harvard-MIT Division of Health Sciences and Technology and the Biological Engineering Division received this years Lemelson-MIT Student Prize, a $30,000 award given to an MIT senior or graduate student who demonstrates remarkable inventiveness.
Berry received the prize primarily for his stroke treatment, which grew out of his research on a complex sugar polymer called heparin and its interactions with a protein involved in forming blood vessels. Scientists had attempted to use the protein as a stroke treatment, but it failed in clinical trials because of serious side effects. So Berry and his colleagues engineered a similar protein that can be given in smaller doses but that still limits brain tissue damage from stroke. Unlike an existing drug that must be administered within three hours of a stroke, Berrys protein may prevent brain damage if given within 24 hours, he believes. And even when administered later, the compound may still help speed patients recovery, Berry says. The protein is moving toward clinical trials.
Dean of engineering Thomas L. Magnanti points to Berrys work as one of the many enormously exciting research projects at the Institute. He notes, however, that as the Council on Competitivenessa forum of industrial, university, and labor leadersstated in a recent report, the United States needs to do more to encourage students to become inventors. This is what the Lemelson-MIT prize is about, he says.
A Gridiron Great
Football standout Kevin Yurkerwich 06 is named an Academic All-American
By Kathryn Beaumont
Kevin yurkerwich 06 could have been a top-ranked skier. But as a senior in high school, he turned his attention toward his other athletic love, football. For MIT, its a good thing he switched. Since he walked onto the MIT playing fields in fall 2002, Yurkerwich has been a defensive standout, his accolades culminating in his designation as a 2004 Academic All-Americanthe highest collegiate honor a student-athlete can receive, and one that gives equal weight to academic and athletic performance. Its particularly fitting since Yurkerwich, a chemistry major, will graduate this spring after only three years at the Institute.
To graduate early, Yurkerwich took as many as 87 units a semesterthe equivalent of seven and a quarter standard classes. He managed his study time by doing lab research from 6:00 a.m. until classes began at 10:00 a.m. After class, football offered him an escape from the daily grind of problem sets and exams, he says.
Football may have been an escape, but Yurkerwich, a defensive end and a long-snapper, was as committed to his sport as to his studies. His teammates named him most valuable player. He also ranked first in tackles in the New England Football Conference, with 12 tackles per game, and third at MIT in career sacks (16.5).
In his 27 years at MIT, football coach Dwight Smith has coached 24 Academic All-Americans. He ranks Yurkerwich with the best of the best. Even though he was always taking heavier loads, he could refocus and get into football, Smith says.
Yurkerwich will attend graduate school next year to pursue a doctorate in chemistry. Already, he has been accepted at schools where he could potentially walk on as a long-snapper. Still, he knows that what he had at MIT was special: Yurkerwichs lab partner is teammate Matt Ramirez 06, the kicker and punter. Not only do we spend a million hours in lab together, Yurkerwich says, but I spend a million hours long-snapping to him. You dont see that at any other school.
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