Accessibility links

Our World — 8 December 2007


MUSIC: "Our World" theme

Straight ahead on "Our World" ... another milestone in harnessing stem cells to cure disease ... how fat children can become adults with heart problems ... and new treatment for amputees:

SMITH: "It doesn't bring the part back by any means. It doesn't begin to make up for the loss that they have. But it's been really exciting to see a small way to connect with the part that's gone."

Restoring some sensation despite the loss of a hand, saving lives by changing diet, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

Scientists reported this week that they have used modified skin cells to cure a blood disorder known as sickle cell disease in mice.

The mouse skin cells were genetically modified to act like embryonic stem cells, which have the potential to become any kind of cell in the body.

The modified cells are similar to the ones announced by American and Japanese researchers two weeks ago. Those researchers used human cells, but did not attempt to treat disease.

In a paper published online Thursday in SciencExpress, a team led by Rudolph Jaenisch of the Massachusetts Institute of Technology described how they implanted cells in a kind of bone marrow transplant.

The result was a fresh supply of healthy blood cells that crowded out the diseased sickle cells.

A member of the research team, Tim Townes of the University of Alabama, said in a Science magazine podcast that they hope to adapt the procedure to treat human patients.

TOWNES: "Our goal is to cure sickle cell disease in human patients, and we've worked on the disease for over 20 years. So we're committed to correcting sickle cell disease, absolutely."

Embryonic stem cells are unspecialized cells that have the potential to develop into any kind of cell in the body. If that ability can be harnessed, stem cells may represent an entirely new way of treating many diseases, from diabetes to Parkinson's.

Research on embryonic stem cells in the United States has been limited by ethical concerns because the cells come from human embryos, which are destroyed in the process, which is why the work of the Japanese and American researchers two weeks ago got so much attention.

In the experimental treatment of the sick mice, the animals' immune system was knocked out with radiation, creating one big advantage for this new type of treatment: because the mouse is getting stem cell-like cells that come from its own body, there is no risk of rejection.

TOWNES: "And I think, of course, that's the most promising part of the procedure. It's that the recipient is getting his or her own cells back. They're genetically identical. And so the immunosupression, in the end, I think, in humans will not have to be as severe."

Right now, the process for converting ordinary skin cells into so-called induced pleuripotent stem cells is not safe enough for humans. But several research teams are working on that problem.

Two weeks ago, Kyoto University researcher Shinya Yamanaka told me he expects the first human patients to be treated in the near future.

YAMANAKA: "I would say it should be less than five years."
Q: Less than five years before this is clinically used?
YAMANAKA: "Well, in some case of clinical usage, at least for clinical trial."
Q: That's pretty remarkable.
YAMANAKA: "That's what we hope. We'll do our best."

Hard to say at this point whether we'll look back and consider Prof. Yamanaka wildly optimistic ... or overly conservative.

In many countries, children are eating more and exercising less, causing them to gain weight. So many children have become obese that medical experts call this widespread increase in obesity an epidemic. And some researchers suspect this weight gain in childhood might lead to the earlier onset of adult diseases. Health reporter Rose Hoban has the details.

HOBAN: Danish researchers say they've found a relationship between childhood obesity and the risk of adult heart disease. They examined health records of children born between 1930 and 1976 and calculated their body mass index — or BMI — for each one through their lifespan.

BMI is a measure that takes into account both height and weight. The researchers found children with higher BMIs grew up to have higher rates of heart attack — and at earlier ages.

In a commentary accompanying the research, U.S. physician David Ludwig discusses the implications of the Danish findings.

LUDWIG: "It's one thing for an overweight 45 year old to develop type 2 diabetes at age 55 and suffer a stroke, a heart attack or renal failure at age 65. It's a very different thing if the clock starts ticking at age ten."

HOBAN: Ludwig says he treats many overweight children in his practice in Boston, Massachusetts, and sees them developing problems ranging from heart disease to bone loss and even psychological disorders — at younger ages.

LUDWIG: "And the potentially most frightening aspect of the epidemic is the possibility that obesity itself in one generation can accelerate the rates of obesity in the next generation."

HOBAN: Researchers now believe that babies developing inside an obese or diabetic woman are exposed to altered blood sugar and hormone levels. This creates changes in the metabolism of the child. And Ludwig says says it's possible those changes even affect the structure and function of the child's body — increasing the risk for obesity and related diseases for the child throughout its entire life.

Ludwig says he advises his patients to eat a diet that minimizes the effects of food on blood sugar levels.

LUDWIG: "The diet that we recommend is based on an abundance of fruits, vegetables and legumes — grain products in their least processed state possible, which means going easy on the white bread, white rice, prepared breakfast cereals and potato products. And we actually recommend no particular reduction in fat content. As long as that fat is healthful — olive oil, flax, nuts, avocado, fatty fish."

HOBAN: The Danish article and Ludwig's commentary are published in this week's issue of the New England Journal of Medicine, which provided Dr. Ludwig's comments. I'm Rose Hoban.

And one more health story this week. Experts say the death toll from ailments such as cancer and heart disease can be reduced by almost 14 million over the next decade by reducing the amount of salt people eat and curbing their use of tobacco. VOA's Jessica Berman reports.

BERMAN: In 2005, the World Health Organization set a goal of reducing the death toll from chronic illnesses by two percent each year for the next 10 years. Chronic diseases are non-communicable illnesses that include heart disease, cancer and diabetes.

Toward that end, an international team of investigators looked to see what contribution salt intake reduction and stepped up tobacco control measures would make.

Researchers, led by Perviz Asaria of the British charitable organization King's Fund, in London, analyzed the impact of a 15 percent reduction in salt consumption in 23 countries, which carry 80 percent of the world's chronic disease burden. The countries include the United States, Russia, India, Vietnam, Ethiopia, Burma, and Nigeria.

Asaria says investigators looked at the results of other studies of people from societies with different levels of salt intake.

ASARIA: "Studies have looked at those societies and have shown in those societies where salt consumption is high, as you age your blood pressure goes up quite dramatically, which is interesting to see. So, in very tribal societies where salt isn't very easily available or not commonly used in food, people's blood pressure tends to stay about the same level they had when they were age 20."

BERMAN: Elevated blood pressure is a well-known risk factor for heart disease.

Researchers say 8.5 million deaths can be averted by 2015 if people consume three-to-four-point-five grams of kitchen salt per day, or around a 30 percent less salt than average.

Investigators say this can be achieved through small changes in diet, such as lowering the salt content of soy sauce, avoiding salty foods and using less of it to season food.

The study also looked at stepping up the enforcement of WHO's Framework Convention on Tobacco Control.

Asaria estimates 5.5 million lives could be saved each year if higher taxes on tobacco, anti-cigarette campaigns and smoking bans in the workplace and in public were vigorously enforced.

ASARIA: "Even when implemented at fairly low levels can reduce tobacco consumption by 20 percent, which once again has a impact on the health of the population."

BERMAN: With some simple changes in behavior, the authors estimate it would cost about 36 cents per year per individual to avert the millions of deaths per year caused by chronic diseases.

The results of the study were published in the British medical journal, the Lancet. Jessica Berman, VOA News, Washington.

Time again for our Website of the Week, when we showcase interesting and innovative online destinations.

This time it's an online library with a rather ambitious goal.

SHAMOS: "Universal Digital Library is a project started at Carnegie Mellon more than 10 years ago with the unabashed objective of digitizing all published works of man and making them freely accessible over the Internet at any time, any place, for anybody."

Professor Michael Shamos of Carnegie Mellon University in Pittsburgh is a director of the Universal Digital Library at u-l-i-b dot org. When he says "published works," he's not just talking about books. The library will eventually also include newspapers, magazines, photographs and other media.

Institutions in China, India and Egypt are also involved, and the library has digitized more than 1.5 million books so far in about 20 languages. Most of them are older works, no longer under copyright.

The priority for adding books to the digital library is pretty much based on what's available. Not every university library is willing to lend out thousands of books for months at a time while they are scanned.

SHAMOS: "We had many debates about this early in the project. Do you convene a committee of scholars to pick the million most important things there are on Earth? I don't think we could ever do that. So instead of doing that we said, look, the ultimate goal is to digitize everything. If you're going to do that, it doesn't matter what you do first."

Shamos says the Universal Digital Library will equalize opportunities for those who don't now have access to a great library or the means to buy lots of books.

SHAMOS: "If there happens to be some brilliant kid who lives in an impoverished town in India, and he doesn't have access to educational materials, he will never be able to develop into the kind of genius that he might be. And so, this is critical for dissemination of information to those who don't have access."

But you don't have to be a budding young genius to use the Universal Digital Library. All you need is an Internet connection to ulib.org, or get the link from our site, voanews.com/ourworld.

MUSIC: Jim Salestrom — "The Library Song"

You're tuned to VOA's universal digital science and technology magazine, Our World. I'm Art Chimes in Washington.

Researchers in Chicago say they've helped amputees to feel sensation — as if they still had their missing hands — by surgically re-routing the nerves that transmit that feeling. As Stephanie Lecci reports, they say that renewed sense of touch could lead to better prosthetic limbs.

LECCI: Nineteen months had passed since Claudia Mitchell lost her arm in a motorcycle accident.

But one day in 2005, she suddenly was able to feel her missing hand — through the skin of her chest.

MITCHELL: "So I'm in the shower, and you know, normal temperature hot water. And it hit my chest and I could actually feel my hand, and I was like, oh wow, it feels like something hot is on my hand."

LECCI: That sensation returned months after surgeons re-routed nerves that once went to her arm into her chest to help her move her prosthetic arm more smoothly.

A similar procedure on another patient had brought back the feeling of the missing hand.

Doctors hoped it would work for her as well.

Through the former hand nerves, now in her chest, Mitchell can feel heat and cold, soft and hard pressure, and even the sensation of her finger being bent back.

MITCHELL: "It's not the exact same feeling of touch on a normal part of my body. But I can identify there's this area on my chest, okay, that's my index finger, that's my pinky, that over there is my thumb, and when it's pressed on, it feels kind of, you know when your leg goes to sleep or your arm goes to sleep and it wakes up, that little kind of tingly feeling, it's a little bit like that."

LECCI: Mitchell's been working with sensory neurophysiologist Paul Marasco of the Rehabilitation Institute of Chicago.

He's co-author of a recent study on the restored hand sensations that occur after the nerve transfer surgery published in the Proceedings of the National Academy of Sciences.

LECCI: Today, Marasco is testing just what Mitchell can feel of her missing hand.

He places pronged instruments on her chest to see if she can tell which way they're pointed.

MARASCO: "Okay, ready?"
MITCHELL: "I'm ready."
MARASCO: "All righty."
MITCHELL: "Vertical."
MITCHELL: "Horizontal."
MITCHELL: "Hor- no, vertical."

MARASCO: "It appears that after being rewired the nerves that brought in the sensation, they actually grew through the muscle out into the skin and then re-established the sensation from the missing limb in the skin of the chest."

LECCI: Interestingly, he notes, the sensation in the chest isn't lost, so to the patient, touching the skin where the hand nerve has been relocated feels like a touch on both the chest and the hand.

Marasco says the rewiring surgery and the sensory feedback it restores could lead to better prosthetic limbs, by allowing improved connections between mechanical sensors on the prosthesis and an amputee's remaining nerves.

He says it's possible that one day, an artificial hand could give its owner something like the kind of feedback we get from a natural hand.

MARASCO: "We have sensors in fingertips of the experimental arms that we've worked with. And when they grab onto an object or touch an object, it sends a signal to this little plunger on their chest that pushes into, you know, say, the thumb and the pointer finger, and gives them a sense that they're squeezing."

MITCHELL: "To me, this is a revolution when it comes to the way prostheses are operated."

LECCI: Claudia Mitchell says sensors that relay feelings of touch would give her and other amputees more control over their prosthetic limbs.

MITCHELL: "You're not going to squeeze that banana until it gushes before you can open it. You would be able to feel a glass sliding in your hand with the condensation rather than it completely falling and breaking before you even knew it was going to fall. Being able to know that something you picked up with your prosthesis that you can't feel is hot, so you shouldn't reach over and grab it with your other hand. All those types of things that we really just don't even think about, it'll be nice to be able to have that back."

LECCI: Researchers are working on ways to achieve that level of sensitivity and control, and orthopedic surgeons, like Douglas Smith at Seattle's Harborview Medical Center, are watching developments carefully.

Smith, who was not involved in the study, has performed seven nerve relocation surgeries.

He says even if prostheses capable of such sophisticated movements are a while off, just being able to feel their missing hands is a true advance for amputees right now.

SMITH: "The individuals that have developed this new sensation, it has been something very special to them. It doesn't bring the part back by any means, it doesn't begin to make up for the loss that they have, but it's been really exciting to see a small way to connect with the part that's gone."

LECCI: For Our World, I'm Stephanie Lecci in Chicago.

With international climate talks under way this week in Bali, Indonesia, the non-profit Pew Center on Global Climate Change released a report examining the impact climate change is having on different regions of the United States. The study argues that federal, state and local decision-makers must work both to mitigate global warming and to adapt to its consequences.

SKIRBLE: The report looks at specific impacts of climate change in four regions of the United States. Eileen Claussen, the president of the Pew Center for Global Climate Change, sums up the findings:

CLAUSSEN: "The report finds that Midwestern heat waves and western wildfires are both likely to become larger, more frequent and more intense as the result of climate change. Gulf Coast wetland loss and Chesapeake 'dead zones' are likely to be exacerbated by climate change making them more difficult to restore."

SKIRBLE: The case studies consider how non-climate factors like population growth, development and land management interact with the problems of a warming planet. For example, along Louisiana's Gulf of Mexico coastline, wetlands play an important role in the quality of life, helping to sustain the U.S. economy and protecting people and property from the dangers of storm surges.

Report co-author Robert Twilley, professor of environmental science at Louisiana State University, says continued coastal development, coupled with the anticipated rise in sea levels, could drown the wetlands.

TWILLEY: "The significance of this is that under storm events such as hurricanes these open waters increase the risk of coastal communities to flooding events and coastal hazards."

SKIRBLE: The Gulf Coast is also critical to domestic oil production. Twilley says what happens to the wetlands directly affects offshore industry and land-based operations in the region.

TWILLEY: "Some of the companies that are forward- thinking about this risk see that our [State of Louisiana] restoration program really represents a coupling where corporate sustainability is co-dependent on environmental sustainability. So they see the investments in our restoration program as investments in their industry as well."

SKIRBLE: Looking at evidence of climate change in the American west, the report notes that over the past decade, earlier spring snowmelt and hotter, drier summers have led to more wildfires. Report co-author Dominique Bachelet, director of Climate Change Science at the Nature Conservancy makes this prediction:

BACHELET: "I believe that the deadly combination of human behavior and climate change has created a scenario where we will likely see more severe wildfires like the ones we've seen in 2007."

SKIRBLE: Carbon dioxide - a greenhouse gas - also promotes tree growth. But that may be too good for the forest, unless the growth is managed properly to lessen fire risk. Blachelet says the situation is made worse when the forest ecosystem is fragmented by roads and buildings.

TWILLEY: "One thing that we have seen happening is that when you build roads, the roads open up a way through the forest to bring warm, dry air and may that may dry up the surrounding under story near the roads and [that] effects the fire vulnerability of these forests."

SKIRBLE: The report also focuses on the Chesapeake Bay on America's mid-Atlantic coast, the largest and most productive estuary in North America. Agricultural runoff, largely from farms, but from cities too, has led to hypoxia, or an inadequate level of oxygen in the coastal waters. That's created dead zones, which affect fisheries and recreation in the region. Report Co-author Donald Boesch, University of Maryland professor of marine science, says climate change will exacerbate the situation.

BOESCH: "Many of the anticipated changes, for example increased spring flow during the spring and winter, warmer temperatures, calmer summer winds and increasing [coastal water] depth due to sea level rise would move the ecosystem in the director of worsening hypoxia."

SKIRBLE: A growing number of scientific studies document these kinds of changes according to the Pew Center on Global Climate Change. Director Eileen Claussen wants decision-makers who read the report to understand that while climate change is a global problem, its effects are felt locally.

CLAUSSEN: "Every planner, every developer, every policy maker, will need to factor climate change into the equation, beginning now."

SKIRBLE: Claussen says getting the right policies in place now is essential to reducing the risk from current and future climate-change impacts. I'm Rosanne Skirble.

MUSIC: "Our World" theme

That's our show for this week. If you'd like to get in touch, email us at ourworld@voanews.com. Or use the postal address —

Our World
Voice of America
Washington, DC 20237 USA

Rob Sivak edited the program. Eva Nenicka is the technical director. And this is Art Chimes, inviting you to join us online at voanews.com/ourworld or on your radio next Saturday and Sunday as we check out the latest in science and technology ... in Our World.

XS
SM
MD
LG