MUSIC: "Our World" theme
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.
MUSIC: "Our World" theme
That's our show for this week.
If you'd like to get in touch with us, our email address is ourworld@voanews.com. Or use the postal address -
Our World
Voice of America
Washington, DC 20237 USA
Rob Sivak is our editor. Bob Doughty is the technical director.
