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This week on Our World: A promising stem cell treatment for diabetes ... a genetic key that might help unlock the cause of stroke ... and a community of microbes living in the dark under a half-kilometer of Antarctic ice ...
MIKUCKI: "The first time I saw it ... I knew that this rust or this stain on the glacier was due to iron. I thought about, hmm, what microbes are there taking advantage of that energy source."
Those stories, an Earth Day story on building with greener concrete, and more.
I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Adult stem cell treatment for diabetes shows promise
Hundreds of millions of people around the world have diabetes. Many of them live a relatively normal life. But there's potential trouble when patients are not careful about what they eat or when they fail to take their medication, which may include a daily insulin injection. Diabetics are at greater risk for heart attack, blindness, amputation.
Diabetes is linked to obesity and a lack of exercise, and it used to be seen mainly in the rich, industrialized countries. But as more people around the world adapt a western diet and lifestyle, diabetes has spread.
DeANGELIS: "I don't think I need to tell you that diabetes mellitus - type 2, especially - is a pandemic right now. In just a matter of 25 years, we've gone from 35 million to 235 million [cases] worldwide. So we're in trouble."
Dr. Catherine DeAngelis is editor of the journal of the American Medical Association, JAMA, which this week published a special issue devoted to diabetes.
Most diabetics can do a pretty good job of controlling the disease with diet and often with a daily injection of insulin. The ultimate goal for diabetes, though, is a cure, or at least a one-time treatment that will work for an extended period of time.
Since diabetes is usually caused by the failure of the body to produce enough insulin, some researchers have been trying to figure out how to get the body's insulin factory back up to speed. Insulin is produced in the pancreas, in cells called islet cells.
One approach that is showing some promise involves using the body's own adult stem cells to promote islet growth. Dr. Richard Burt of Northwestern University described the results from a small study conducted in Brazil with colleagues from the University of São Paulo.
They separated stem cells from the blood of the diabetics in their study, then suppressed the immune system, so the re-injected stem cells could build up the pancreatic islet cells.
BURT: "We do what's called mobilization, and that's collecting the stem cells from the blood. And then we preserve it, freeze it down and give the patient what we call 'conditioning regimen,' and that is to condition your immune system, to knock it down. And then we infuse, reinfuse these stem cells, let the patient recover, and then they're discharged from the hospital."
There were only 23 people in the study, but after just one treatment most of the patients were able to live without insulin for more than a year, averaging two and a half years.
BURT: "This is the first time in the history of treating Type 1 diabetes that patients have normal blood sugar and are drug-free - no drugs at all, no other treatments - after one intervention."
There were only a few, mostly mild side effects. But the treatment typically required two to three weeks in the hospital.
Burt says a larger test of the procedure is planned for both Chicago and Sao Paolo, pending approval.
People with diabetes are at risk for a number of other diseases.
So Frans Wackers of Yale University wanted to see if diabetics who had no symptoms of heart disease could benefit from screening for cardiovascular illness.
In an separate paper also published this Dr. Wackers described a study in which he took a group of diabetics who had no symptoms of heart disease and screened half of them for hidden heart problems.
WACKERS: "And so the notion is that patients with diabetes are walking around with a 'time bomb' that ticks and can go off any time, but we don't know when."
The other half got no screening. The group that was screened were given their results, but there was no requirement that they get any additional treatment.
The researchers figured that diabetics who were informed of possible heart problems would get treatment - maybe take drugs to lower blood pressure or cholesterol - and that they would be less likely to have a heart attack or die.
But Wackers told reporters in fact there was little difference between the two.
WACKERS: "And after five years the total incidence of cardiac event is 2.7 percent - again, much lower, actually, than we anticipated. Now is this due to screening? Well, here's the group which had no screening whatsoever, and the two curves of events over time are almost superimposable, and there was no statistical difference."
So there were fewer cardiac events - including heart attacks - and fewer people died than they expected, and there was no significant difference between the diabetics who were specifically told that they may have a heart condition, and those who were not screened.
So what explains this? Frans Wackers says that midway through the study the American Diabetes Association came out with a recommendation that all patients with diabetes should be treated like they have heart disease: get aspirin and cholesterol-lowering drugs, control their blood pressure, and so on.
Both groups in the study apparently followed that advice, and that seems to account for the lower-than-expected number of heart attacks and other incidents.
Osteoporosis drug may also help heal broken bones
Broken bones that will not heal can be deadly, especially for older people. Now, it appears that a drug used to treat a degenerative bone disease may also help speed up the healing of bones that break. Jim Hawk reports.
HAWK: Some of the most amazing discoveries in medicine occur when researchers notice that a drug meant to treat one thing can treat something else. One of the best known examples is aspirin. While it is a commonly used painkiller, doctors discovered it also helps prevent heart attacks.
In a promising new case of medical serendipity, a drug approved for the treatment of osteoporosis has been found to jumpstart the healing process in elderly patients with broken bones.
PUZAS: "So if an old person breaks their bone, many times they cannot mount the stem cell stimulus and then eventually allow that bone to unite and knit itself back to normal. We've been able to show that this drug rapidly stimulates fracture healing."
HAWK: Dr. Edward Puzas, head of bone research at the University of Rochester Medical Center [in New York state], says the drug teriparatide normally helps build up and strengthen the bones of osteoporosis patients. But researchers began to notice that when it was given to patients who had bone fractures, the fractures began to close. Puzas says the drug appears to heal bone by stimulating the body's naturally occurring stem cells.
PUZAS: "It works likely through recruiting stem cells - stem cells in the body, and we're not talking about embryonic stem cells - the controversial stem cells that everybody is worried about - we're talking about adult stem cells. And these are cells that have the potential to differentiate into a few specific tissues, one of which is bone."
HAWK: Teripartide has been shown to speed the healing of bone in mice, and the National Institutes of Health in Washington is now funding a controlled human study. Final results are not expected until the end of the year, but Puzas says some of the subjects have shown remarkable improvement already in bone healing and levels of pain.
PUZAS: "But it is pretty amazing, actually, the results that we've seen. And if it turns out that those are the patients that were on the drug, I think we're going to find something here."
HAWK: It could be a life-saving find: one-fourth of all older women who suffer pelvic fractures have fatal complications. I'm Jim Hawk.
Scientists discover gene mutation that increases stroke risk
An international team of scientists has discovered a genetic mutation that increases the risk of stroke by 30 percent. Stroke is caused by a blood clot or other loss of blood supply to the brain, and it's a leading cause of paralysis and death. VOA's Jessica Berman reports.
BERMAN: Scientists long have understood the environmental risk factors that contribute to stroke, such as smoking and high-fat diets, but they've struggled to find the genes that underlie the heritable component of the disease - until now.
In a study examining the genetic material of 23,000 people, U.S. and Dutch researchers found that stroke victims were about one-third more likely to have a mutation in a gene called NINJ2.
Researcher Eric Boerwinkle says the mutated gene is not a death sentence for those who carry it.
BOERWINKLE: "I think what's important is if a person is now known to have this particular gene variation or gene mutations, that doesn't necessarily mean they are predestined to have a stroke. That's not true."
BERMAN: Boerwinkle is a researcher at the University of Texas in Houston, and co-author of the study which appears in this week's New England Journal of Medicine. He stresses that other factors contribute to stroke, including high blood pressure and a build-up of cholesterol that can choke off the blood supply, killing brain tissue.
Boerwinkle adds that, as with other diseases, no single gene is involved in stroke.
BOERWINKLE: "This discovery shows and documents that the science we have in place can identify the genes - the several genes -- that are contributing to stroke risk. When those genes are found and combined into a diagnostic test, then individuals can have that test and use it to guide their lifestyle choices."
BERMAN: But sophisticated genetic testing may not be necessary, says David Goldstein, a professor of molecular genetics at Duke University. He wrote an editorial in the New England Journal suggesting that large population studies like Boerwinkle's that pinpoint the location and distribution of abnormal genes don't offer much information on the cause of a disease or how to cure it.
GOLDSTEIN: "Most of the genetic findings are of such small effect that you would do as well or better just using family history, for example."
BERMAN: But Goldstein says population studies such as the one identifying the stroke mutation may be of more help to researchers than to patients, since they point to regions of the human genome where scientists can narrow their search for the heritable causes of disease. Jessica Berman, VOA News, Washington
The human body illustrated on our Website of the Week
Time again for our Website of the Week, when we showcase interesting and innovative online destinations.
There are a lot of medical sites on the web, many of them offering thousands of pages of information about health and diseases. Our Website of the Week is different. It focuses on using spectacular videos and illustrations to explain how the body works.
TSIARAS: "The Visual MD is a new way of looking at health information on the Internet. By using visuals from real human data we can finally see the disease, the causes, the consequences and the solutions. And for the first time understanding those things that afflict us and pathways back to health."
Alexander Tsiaras is the founder of TheVisualMD.com. The images, which show blood cells coursing through the body or kidneys filtering out toxins, are based on actual medical data.
"The digital files from medical imaging devices like CAT scans, MRIs, and high-end microscopes are transformed into awe-inspiring pictures that reveal what is going on inside each of us."
The stunning pictures are the work of a team of artists and technicians working with powerful supercomputers. And medical experts insure the product is accurate.
TSIARAS: "Whenever we do a project, we always have a number of key opinion leaders - people who are tops in their field - in hypertension and in cancer [etc.] - and they review every piece of material to make sure that it's scientifically vetted. So nothing goes out unless it's been reviewed."
The site just launched a few weeks ago, and more enhancements are planned, including a customizable section called My VisualMD.
Learn about health and the human body with the help of some amazing pictures at TheVisualMD - that's theVisualMD.com, or get the link to this and more than 200 other Websites of the Week from our site, VOAnews.com/ourworld.
MUSIC: Laurie Lewis - :Visualize"
You're listening to VOA's anatomically correct science and technology magazine, Our World. I'm Art Chimes in Washington.
Million-year-old microbe colony discovered under Antarctic glacier
Scientists in Antarctica have discovered a colony of microbes that appear to have lived for millions of years under hundreds of meters of an ice formation called Taylor Glacier.
Jill Mikucki led the international team that discovered life in a place without light or oxygen, in a briny solution so salty that it doesn't freeze even at five degrees below zero.
MIKUCKI: "As a microbial ecologist, geomicrobioligist, it's hard for me to imagine a place where life can't take hold. As long as there's energy there, you're bound to find life."
At the nose, or front of Taylor Glacier is a well-known formation that sounds like something out of a horror movie: Blood Falls. But the red ice that gives Blood Falls its name didn't scare off Mikucki.
MIKUCKI: "It's a real intriguing curiosity, and the first time I saw it ... I knew that this rust or this stain on the glacier was due to iron. I thought about, hmm, what microbes are there taking advantage of that energy source."
The briny water that discharges at Blood Falls from beneath the glacier flows out only intermittently, so it took her several years of trying to get a fresh, uncontaminated sample. How the water got there, she thinks, is that seawater on the surface got trapped a million and a half or more years ago as the glacier advanced and covered it up, sealing it and all the microscopic life swimming around in it, under the ice.
MIKUCKI: "It's undergone some pretty dramatic change. It lost all its sunlight. It became permanently cold and dark. It's very salty. It's concentrated seawater. And so, only the strongest survived."
The briny liquid that's been trapped under the glacier is rich in iron, and minerals, and it supports what could be a very large ecosystem.
Q: Do you have any idea how large it is?
MIKUCKI: "Not- no. (laughs) There was one study where they did some ice-penetrating radar work, and they detected this anomaly in their data that suggested there was some liquid and it's in a depression that's 80 meters deep, 80 meters below sea level. So it has a potential to be a pretty large lake."
Q: How thick is the ice at this point?
MIKUCKI: "Four hundred meters thick"
The bacteria that live down under Taylor Glacier are adapted to the extreme conditions, but they're not so exotic that they can't thrive in warmer environments, too.
MIKUCKI: "Some of these bacteria are incredibly resilient, and I can actually grow them on a petri dish in the laboratory. They tolerate the cold and can grow in it, but they'll do just fine at higher temperatures as well.
Well, all this is interesting, but I asked Jill Mikucki exactly what's the point of studying an ecosystem full of microscopic life hundreds of meters beneath the Antarctic ice?
MIKUCKI: "We have a lot to learn from the microbes that survive in these kinds of environments and have adapted these cold, low-energy systems. They're very efficient. I think they're fabulous systems to study."
I reached Dr. Mikucki at her office at Dartmouth College in New Hampshire. Her paper on the discovery of a cold, dark, and very ancient colony of microbes was published this week in the journal Science.
Building with concrete: cheap, durable, and now getting greener
And finally today ... concrete has been prized as a building material for more than 2,000 years. It's a seemingly simple blend of inexpensive ingredients that's easily molded, strong, and flexible. So it's no wonder concrete is the most widely used man-made building material in the world. Unfortunately, making concrete is not an environmentally friendly process. So as we look ahead to Earth Day this week, VOA's Adam Phillips reports on what's being done to make concrete "greener," without sacrificing low cost and legendary durability.
MEYER: "It's very strong and, if it's done correctly, it can be very durable. The Romans built structures 2000 years ago like the Pantheon. It's still doing very well 2,000 years later."
PHILLIPS: That's Christian Meyer head of Columbia University's Department of Civil Engineering. He says concrete's so-called "mechanical properties" explain its universal popularity as a building material.
MEYER: "Also, it is very affordable, very cheap, compared to with other building materials. And you can get it everywhere. You make concrete in almost every country in the world because the ingredients that you need you find everywhere."
PHILLIPS: Every year, nearly a cubic meter of concrete is produced for every man, woman, and child on the planet. Meyer says satisfying that demand requires a lot of land.
MEYER: "If you want to produce ten billion cubic meters of concrete, you need ten billion meters of material, okay? That's the conservation of mass. And where do you get that? You have to quarry the stone, you have to quarry the aggregate and get the sand from sand pits. That's a huge amount of materials ."
PHILLIPS: But concrete's very durability is also one of its biggest drawbacks, according to architect and Columbia University professor Michael Bell.
BELL: "It's not a material that comes down easily when it's put up. So whatever we are building in Beijing, Shanghai, in India right now, those buildings are going to stay. Or if they aren't going to stay, getting them down is going to produce a massive amount of waste."
TEXT: Until recently, most of the world's used concrete went into landfills, at enormous environmental cost. But today, some manufacturers, especially in Europe, are crushing used concrete and recycling it for use as an ingredient in new concrete.
The greatest environmental threat associated with concrete is that the processing of one of its key ingredients, cement, releases large amounts of carbon dioxide, or CO2, a greenhouse gas associated with global warming. About a metric ton of CO2 is created for each metric ton of cement produced, and the process now accounts for as much as seven percent of the world's industrial CO2 emissions.
Why so much CO2?
First, CO2 is created as a natural chemical byproduct when the ingredients in traditional cement - called Portland cement - are combined. Second, cement is made by heating a chemical mixture - mostly limestone, clay, iron ore and other minerals - in a kiln to high temperatures usually exceeding 1500 degrees celsius. The energy for that heat usually comes from burning oil or coal, both of which release CO2 during combustion. Fortunately, says Christian Meyer, there are ways to reduce the carbon footprint of the cement we make and use.
MEYER: "The most common one is that we simply use less cement and replace it with some other material that has cementitious [cement-like] properties and happen to be byproducts of other industrial processes. The most common example that is well known is fly ash. Fly ash is a byproduct of coal combustion."
PHILLIPS: U.S. federal law now requires that power plants either capture this fly ash so it doesn't pollute the atmosphere, or pay a hefty fine for the fly ash that is released.
MEYER: "But it was found that this fly ash is an excellent cementitious material. Because it can react together with the cement and the water and produce better concrete if you use fly ash than if you don't use fly ash. Not only that, it's also cheaper than cement. So it's a win-win situation here."
PHILLIPS: It is projected that power plants in the future may be built alongside cement factories, so that the waste from one industry may be easily used as the raw material for another.
PHILLIPS: Also, new types of cement are being developed or are already in use. One is a white cement that is easily pigmented to create colorful visual alternatives to the drab gray of traditional cement. That reduces visual pollution. Another uses titanium-oxide particles that break down many of the organic pollutants already in the air, and help clean the atmosphere. In an era when nations around the world are industrializing, and cities are growing at an unprecedented pace, making the world's favorite building material a little greener is an achievement as solid as?concrete.
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Our World — 18 April 2009
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