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Our World — 25 October 2008

MUSIC: "Our World" theme

This week on "Our World" ... A better way to treat people with HIV and TB ... Health care and the U.S. presidential candidates ... and studying forests to learn why wildfires are on the rise...

PIERCE: "If you have a tree that kind of is at the edge of its comfort zone, so to speak, it will be a more sensitive recorder of those environmental stresses."

Those stories, how rural migrants are clustering near protected environments, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

Study highlights best way to treat HIV-TB patients

In many parts of the world, patients with HIV arrive at a clinic not because they're sick with HIV, but because they've come down with tuberculosis. Now some new research is revealing the best way to treat these patients. Rose Hoban reports.

Tuberculosis is epidemic in many poor countries that have high rates of HIV. But Dr. Salim Abdul Karim from the University of KwaZulu-Natal in South Africa says there's no general agreement on how to treat the two diseases when a patient has them together.

KARIM: "And if you had to ask 10 medical practitioners how you would treat this patient who has these two conditions, you would get ten 10 different answers."

HOBAN: Anti-retroviral drugs used for treating HIV were created and tested in Western countries where there aren't many people with tuberculosis. As a result, researchers never studied the best way to treat HIV and TB together and the possible interactions among different drugs.

But in Southern Africa, patients frequently do have both diseases simultaneously, and doctors struggle to treat them. To begin with, Karim says medications for tuberculosis and HIV can interact with one another.

KARIM: "The TB drugs induce certain key enzymes in the liver that result in the antiretroviral drugs being metabolized more quickly. And the particular TB drug that does this is called rifampicin. And rifampicin is a key drug in TB, so you cannot exclude it from TB treatment."

HOBAN: Another problem is that some patients actually get sicker after taking their TB drugs. Karim says that's because the body's immune system goes into overdrive once it gets some help from medication. The third problem is that patients getting treated for TB and HIV simultaneously end up taking a lot of pills.

KARIM: "And each of these drugs has its own side effect profile. So we have a lot of concern that when you put patients on anti-retrovirals, that they might then stop taking their TB drugs because of side effects they're getting from the antiretroviral drugs. It's just the process of having to take seven drugs… I mean, handfuls of medication."

HOBAN: Karim and colleagues from Columbia University in the United States started a study to determine the best way to treat these patients. They recruited more than 600 people to try different ways of taking the drugs. The trial is still going on.

But in August, Karim and his colleagues reviewed the preliminary data. They found that patients waiting to complete TB treatment before getting HIV drugs were 50 percent more likely to die than patients being treated for both diseases simultaneously.

KARIM: "We should encourage all patients who have both tuberculosis and HIV to receive both therapies, both sets of drugs, at the same time. TB therapy, they have to start because they won't die from HIV, they'll die from the TB. Don't wait for them to finish their TB treatment. Start the antiretroviral drugs."

HOBAN: The study results were announced in a press release, rather than the usual publication in a medical journal. Karim says in the time it would take to publish these results, 10,000 people in South Africa alone could die from being treated for TB before getting any anti-retroviral drugs. So he says they've altered their study, and they're urging doctors who see these patients to get them started on anti-retrovirals before completing the six-month course of TB medications. I'm Rose Hoban.

Researchers identify lung cancer gene defect

Scientists say they have identified more than two-dozen genes that are frequently mutated in people with the most common form of lung cancer. The researchers say the findings open the possibility of developing individualized therapies to fight the disease. VOA's Jessica Berman reports.

BERMAN: Genetics researchers at three U.S. institutions have identified 26 genes that are frequently mutated in people with the most common form of lung cancer, adenocarcinoma.

Lung cancer is the number one cancer killer worldwide, accounting for one million deaths each year. About 90 percent of those stricken with the disease are smokers and former smokers.

In a study published this week in the journal Nature, the researchers describe using the latest genetic sequencing technology to sort through 625 genes taken from the tumors of 188 lung cancer patients.

The investigators then compared the tumor changes to the DNA in healthy tissue from the same patients.

In a teleconference with reporters, senior study author Matthew Meyerson of the Broad Institute at the Massachusetts Institute of Technology in Boston says the cancer genes, known as somatic cell mutations, are not inherited and occur nowhere else in the body.

MEYERSON: "Somatic mutations are important because the mutated genes can be targets for anti-cancer therapy. The reason is that the cancer gene is now different from the normal gene, and so some drugs can now specifically kill cells with the mutated cancer gene."

BERMAN: Senior-co-author Richard Wilson of Washington University School of Medicine in Saint Louis, Missouri, says the development could, in time, lead to targeted therapies for lung-cancer patients.

WILSON: "We should be able to develop much more effective chemo [chemotherapy] drugs, including drugs that also provide for a much better quality of life during treatment for the patients."

BERMAN: The researchers found that some adenocarcinoma genes have been implicated in a number of other cancers, including lymphoma, leukemia, and colon cancer.

Investigators say it is possible that some drugs that show promise against one type of tumor might work against adenocarcinoma.

The work is part of the Tumor Sequencing Project, funded by the National Human Genome Research Institute, to assemble a genome-wide catalog of all mutations involved in the lung disease. Jessica Berman, VOA News, Washington.

Millions of American children do not have health insurance

Nine million American children do not have any health insurance at all, and twice that number have health insurance for only part of the year.

Most children get health insurance coverage through their parents, and most parents get insurance through their jobs. But the number of jobs that don't provide health insurance has been increasing, and that means workers' kids likely don't have coverage either.

In other cases, coverage for children is available, but costs extra. Which means parents sometimes have to make hard choices.

PARENT: "There were times that we'd have to pick — let's see, the first of the month, do we pay the insurance or do we pay the water, sewer and electricity? I mean, if you have to choose between water and electricity, and insurance that you're not using on a daily basis, you know you have to pick your utilities."

That was the mother of an uninsured child, interviewed for a study published this week in JAMA, the journal of the American Medical Association.

Study author Jennifer DeVoe found that about four percent of U.S. children and adolescents do not have year-round health insurance, despite having at least one parent who does have health coverage.

DeVOE: "This is the group that I'm talking about: parent insured all year, child not insured all year. About three million U.S. children."

DeVoe says that gap exists despite a government program called SCHIP [State Children's Health Insurance Program], which is supposed to help.

DeVOE: "We need to expand the State Children's Health Insurance Program to provide relief to low and middle income families. They are falling into this gap. They're earning too much to qualify for public insurance in most cases, and not enough to afford private coverage."

DeVoe found that uninsured children and adolescents whose parents had health insurance were more likely to be of Hispanic origin, and more likely to live with a single parent. Uninsured children were also more likely to be in low-income families, though one-fifth of the uninsured kids were in high-income families.

Medical journal editor criticizes candidates' vague health plans

America's health care system is, at its highest level, perhaps the best in the world. But for providing regular care to regular people at regular prices ... well, the word most often used by critics to describe the system is "broken."

America's health care system has not been much of an issue in this year's presidential election. War and the economy have pushed it pretty much to the sidelines.

But the candidates do have their health proposals. Democratic candidate Barack Obama wants to require larger employers to provide workers with health insurance. His Republican counterpart, John McCain, is proposing a tax break to help people buy their own insurance.

Both candidates write about their plans in this week's issue of JAMA, the same journal that published Jennifer DeVoe's study.

On Tuesday, I asked JAMA editor Dr. Catherine DeAngelis why Americans should be paying more attention to the health insurance issue.

DeANGELIS: We're in deep trouble, and we're trying to bring attention to it, especially now with our election only two weeks away, we're trying to bring people to understand just how dire the situation is, and that if we don't do something very soon, our population's going to suffer so badly, that even though we think of ourselves as having the best health care in the world, guess what, people? We could have the best health care in the world. Right now we don't. I just looked at a statistic the other day. We now rank 43rd in the world in longevity. Two decades ago we were 11th. And we spend more per capita than any other country in the world. Now what is going on? Why can't we solve this issue?

In less than 1,500 words each, McCain and Obama describe their health programs. But DeAngelis says their positions are hard to evaluate in just a page and a half.

DeANGELIS: "If I were to take what I read in what they submitted to us? First of all, I don't know what they're talking about because there isn't enough detail in there for me to decipher exactly what they're going to do. Whichever of them gets in office, I want to see what he does, actually does. What attention he pays to this. And if he's just going to let it go by-the-by, we're going to be in trouble, because the health of our nation is crashing."

The assessment of Catherine DeAngelis, editor of the journal of the American Medical Association, JAMA.

People move to live near national parks and nature reserves

According to the United Nations, one-eighth of the world's territorial area — land and adjacent waters — has been designated as "protected areas."

These include a variety of natural environments, from nature reserves and wilderness areas to managed resource areas, where logging or fishing might be permitted.

In some cases, protected areas have been created and sustained with the help of donor countries and international organizations.

Protected areas such as national parks have sometimes been criticized as the creations of urban elites that don't benefit rural communities by depriving local residents of access to places to hunt, fish, or farm.

But a study published recently in the journal Science may undercut that critique.

Researchers from the University of California found higher population growth in buffer zones just outside protected areas than they did in similar, nearby rural areas. They conclude that the protected areas were actually attracting immigrants.

WITTEMYER: "Many, if not most of the protected areas that we looked at showed that there was much faster growth rates going around them than there were on background rural [growth] rates"

Co-author George Wittemyer is one of the lead authors of the study, which included more than 300 protected areas in 45 countries in Africa and Latin America.

His co-author, Justin Brashares, explained that infrastructure related to protected areas actually attracts migrants.

BRASHARES: "If the goal of the protected area is to sustain biodiversity for generations, then it only makes sense that when we're placing water treatment [facilities], schools, clinics, road networks, and other major amenities, that we think about the likely impacts of those amenities, those draws to human populations, for the protected areas."

The two spoke this week at a symposium sponsored by the Woodrow Wilson Center in Washington.

In some cases, facilities are created outside boundaries of the park or preserve to draw people out of the protected area, but they also apparently bring newcomers from elsewhere. People are also attracted by jobs such as park ranger, and in some cases in the tourist industry.

Wittemyer says the increasing population around the protected area can do environmental damage and possible hurt the new residents as well.

WITTEMYER: "A number of risks are occurring or emerging around these protected areas. And first of all, the obvious one is that biodiversity conservation objectives are being impacted by higher deforestation rates, increasing pressure around the protected area, increased isolation — but also there's a big health risk with emerging infectious disease and how that relates to human [population] densities."

The paper in Science combined a lot of data from a lot of different sources, and not all of it was a perfect fit for what the researchers wanted to measure. For example, the goal of the study was to analyze population growth in a 10-kilometer-wide buffer zone around park boundaries. But the buffer zones didn't exactly correspond to census districts ... and in many countries, population counts were irregular or unreliable anyway.

Jason Bremner of the Population Reference Bureau welcomed the study, but was critical of some aspects of the work, including the basis for the authors' conclusions.

BREMNER: "The reasons for migration I think are diverse, and I don't think the authors provide adequate evidence to show that conservation investments are driving migration to these areas."

That kind of criticism is not unusual. Most research is published exactly for this purpose: so the scientific community can openly evaluate it, criticize it, and provide a roadmap for further research.

Parks and other 'protected areas' on our Website of the Week

One of th sources of raw data for this study is the World Database on Protected Areas. It's just been published online at a brand new website. And we've chosen it as our Website of the Week, where we showcase interesting and innovative online destinations.

The site, at, features information about some 150,000 places on Earth that have some sort of protection against logging, mining, hunting, fishing, or development.

BESANÇON: "Most people think of them as national parks. So, the Grand Canyon. The Serengeti. Many World Heritage sites. And they also have many different objectives. The objectives are strict nature protection, where actually people aren't allowed to go, all the way to the other extreme, where sustainable use of natural resources is allowed by local and indigenous peoples."

Charles Besançon is an official with the United Nations Environment Program, which compiles the database.

The U.N. first began collecting this information 26 years ago, but the website was launched just a few weeks ago, which means it's too early to tell who will be using it, and for what. But Besançon has some ideas.

BESANÇON: "We're expecting that lots of armchair environmentalists will happen across it. We also know many, many people, of course, working in the conservation field, who use the data on a regular basis, and they're dying to get in and see the new online version. And if you're a scientist, you might want to do some analyses from it and make some determinations about biodiversity protection, for example, around the world."

The underlying database is words and numbers, which is key for scientists and other specialists who need the data.

BESANÇON: "But what it makes real and interesting is when you mix it with other data, like satellite imagery or aerial photography. And then you're looking at Mount Rainier [in Washington State] and flying around it. It makes it much more interesting."

National parks, nature preserves and more at the World Database on Protected Areas,, or get the link to this and more than 200 other Websites of the Week from our site,

MUSIC: Paul Winter — "Se é Tarde me Perdoa (Forgive Me If I'm Late)"

You're listening to VOA's fully-protected science and technology magazine, Our World. I'm Art Chimes in Washington.

Probing the link between wildfires and climate change

Finally today, wildfires have always been a part of life in the American West. But the problem seems to have gotten worse in recent years.

Some say it's because fires are now spotted and quickly put out, meaning that when fires do start, they're exceptionally large, dangerous, and destructive.

Others say that the increasing number and severity of wildfires is tied to climate change.

For the past couple of decades, researchers have been working to understand the relationship between climate and wildfire. Sadie Babits reports from the state of Idaho, where scientists are trying to understand more about this connection.

BABITS: Jennifer Pierce wears work boots as she plows down a steep slope in a ponderosa pine forest.

She and her colleague David Wilkins are professors who work for Boise State University's geosciences department. They're in the middle of tall pines in a forest just outside of Boise, Idaho. Suddenly she's crashing across the brambles and heads for this tree.

PIERCE: "Oh that's a great one! Wow! Sweet!"

BABITS: She drops to her knees and shows me how this tree has been scarred by fire.

PIERCE: "You see this little V-shaped, we call them cat face here at the bottom of the tree that's blackened? So during a fire when the bark of the tree gets damaged that preserves a record of that fire as a scar on the tree."

BABITS: Pierce says since the tree has annual growth rings, she can tell when the tree got burned.

It's one way Pierce and Wilkins reconstruct the fire history of this forest. It's also a key to understanding how climate has affected forest fires in the past.

PIERCE: "As we move into a likely warmer and drier future, it's going to be increasingly important to understand the relationship between climate and fire."

BABITS: She says climate is the primary control for wildfires. As the [Western United States] warms, there's less control. Recently, that's meant a lot more wildfires.

WILKINS: "There you go!"

BABITS: David Wilkins is twisting an auger into the tree.

WILKINS: "It's a good upper body workout!"

BABITS: It's a way to take a sample of the rings of this tree. Within a half-minute, Wilkins' auger is stuck. The tree is rotten inside.

Jennifer Pierce takes a look at this sample Wilkins twisted out. The rings — some light, some dark — reveal just how the tree has responded to moisture and temperature.

PIERCE: "If you have a tree that kind of is at the edge of its comfort zone, so to speak, it will be more of a sensitive recorder of those environmental stresses."

BABITS: Tree rings aren't the only clue these scientists use to reconstruct historic climates.

PIERCE: "I didn't bring my big shovel. I kind of feel naked without it."

BABITS: Pierce scrapes away dirt and she finds bits of charcoal. She can sometimes use charcoal for radiocarbon dating. But these won't do.

PIERCE: "But I wouldn't use them for dating because you want to make sure that the charcoal is stratigraphically in place and that you haven't had critters burrowing and mixing things up."

Charcoal can be dated much further back than the tree rings. It helps Pierce and Wilkins understand what happened here thousands of years ago. With samples from other scientists, they'll get a snapshot of ancient climate and how it affects wildfire.

And possibly determine what climate change will mean for forests in the future.

For The Environment Report, I'm Sadie Babits.

Support for The Environment Report comes from the Joyce Foundation, and the U.S. Dept. of Agriculture. Send your thoughts and ideas to feedback at

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

Our World
Voice of America
Washington, DC 20237 USA

Rob Sivak edited the show. Bob Doughty is the technical director.

And this is Art Chimes, inviting you to join us online at or on your radio next Saturday and Sunday as we check out the latest in science and technology ... in Our World.