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MUSIC: "Our World" theme
Straight ahead on "Our World" ... a new drug to battle cholera ... the disease-fighting properties of fruit ... and the promise of gene therapy
RONCAROLO: "And there are now more than 60 patients in the world treated with gene therapy, and more than 30 are completely cured and can have a normal life thanks to gene therapy."
Those stories, a little bug with lots and lots and lots of legs, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Researchers in Bangladesh have tested a drug that cures cholera in most patients, showing that it is a useful new weapon in an arsenal that has grown weak against the cholera organism's growing drug resistance. But VOA's David McAlary reports that drugs alone cannot halt the advance of cholera across the globe.
McALARY: The world is in the midst of a cholera pandemic that began 45 years ago in Indonesia. Cholera is an infectious disease of the small intestine that causes watery diarrhea, vomiting and muscle cramps. In severe cases, rapid loss of body fluids leads to dehydration and shock. Without treatment, death can occur within hours. The disease thrives in contaminated water and United Nations figures show that one-sixth of humanity, one billion people, do not have access to clean water. Another two-and-a-half billion are without sanitation. The World Health Organization says that by 1992, the cholera pandemic feeding on these conditions had swept across the developing world, invading regions that had not seen it in a century.
But medicines that have been a mainstay against this diarrheal illness are growing less effective because of overuse. Physician Michael Bennish of the University of Oxford in England says the vibrio bacterium that causes epidemic cholera has been adapting to the drugs.
BENNISH: "Resistance is developing faster than we can identify new agents and new treatments. We don't have many options left. It's a very meager set of options at this point."
McALARY: Just 10 years ago, Bennish and colleagues found that a single dose of an antibiotic called ciprofloxacin was very effective in treating severe cholera in adults in Bangladesh. But like other cholera drugs, it has weakened against the disease since then, causing the team to test a newer antibiotic called azithromycin.
The results published in the New England Journal of Medicine are hopeful. A single $0.95 dose of azithromycin ended watery diarrhea in two days for three-fourths of the patients who took it. In contrast, ciprofloxacin succeeded in only one-fourth of patients.
BENNISH: "The good news is that we've found a new, effective antimicrobial regimen that is inexpensive and extremely effective. The bad news is that the drug that we've come to rely on for the last 15 years, ciprofloxacin, has all of a sudden proved ineffective because resistance has developed to it."
McALARY: But time may be running out for azithromycin, too. Bennish says the vibrio bacterium is starting to become resistant to this newer drug — at least in Bangladesh.
BENNISH: "If we get widespread resistance to both azithromycin and ciprofloxacin, we're really in a very, very difficult position and there is no easy answer."
McALARY: Bennish says there is a great need to develop new affordable drugs. But he and others acknowledge that drugs cannot hold the line against cholera in a world where billions live in unclean conditions.
The director of the University of Virginia's Center for Global Health, Dr. Richard Guerrant says in developing countries, there is too much emphasis on antimicrobial drugs and oral rehydration therapy — a solution of salts and other substances, such as sugars, which is administered orally.
GUERRANT: "Clearly, the problem is one of lack of adequate water and sanitation. That has created the huge need not only for oral rehydration, but for the antimicrobials that we are rapidly losing. The antibiotic approach is obviously life-saving and tremendously important. Oral rehydration therapy is perhaps the greatest medical advance and perhaps also the greatest indictment of 20th century medicine because we have basically done that instead of the sanitary revolution."
McALARY: Six years ago, United Nations member states set a goal of reducing the percentage of people lacking clean water and sanitation by half as one of several Millennium Development Goals to be met by 2015.
But an analysis by the Center for Strategic and International Studies in Washington says the effort is underfunded and will require an extra $15 to $30 billion in addition to the $30 billion already invested each year in development. David McAlary, VOA News, Washington.
We try to cover a lot of subjects at Our World, but it's been a long time since we've had a story about bugs. So, here's one: Scientists have re-discovered a species of millipede in California that was last reported in the scientific literature almost 80 years ago. Despite the name, millipedes don't actually have a thousand legs, but this one comes pretty close
MAREK: "We rediscovered a population of the species illacme plenipes, which is the leggiest millipede and also the leggiest animal on the planet, out in San Benito County, California."
That's Paul Marek, a graduate student at East Carolina University, who found the elusive creepy-crawly in California last November.
Millipedes typically live about two years, and as they age they add segments ... and legs.
MAREK: "These types of millipedes continue to add legs throughout its life, and this can even occur after sexual maturity."
The illacme plenipes that Marek found crammed hundreds of legs into bodies little more than three centimeters long.
When scientists reported their discovery of this particular species of millipede in 1928, they described what they saw using the best tool available back then — an optical microscope. Today, Paul Marek and his co-author and faculty advisor, Jason Bond, can use a scanning electron microscope to see structures on the tiny body with startling clarity and detail.
MAREK: "What we saw was an amazing diversity on the exoskeleton of this millipede — spines and protuberances, and it's also clothed in these really bizarre hairs or 'setae' that produce — they're hollow at the end — and produce this really interesting silk that has kind of a mysterious purpose. We don't know what it does.
Other millipedes produce this silk just at the very end of their long bodies, but this one produces it over its entire length.
Illacme plenipes is known only in a small area in California south of San Francisco, which Paul Marek describes as a biodiversity hotspot, home of a particularly wide variety of life forms, including many — like this millipede — not known to live anywhere else.
Millipedes as a group are very common throughout the world. There are an estimated 80,000 different species that live in the soil, subsisting on plant material.
MAREK: "Millipedes are an extremely important part of the ecosystem because they recycle leaves, wood and other plant material into soil, and they also recycle nitrogen, carbon and oxygen back into the ecosystem. So they have a very important role. They're like the little garbage men of the ecosystem, if you will."
Paul Marek spoke with us from his office at East Carolina University, in Greenville, North Carolina. His paper appears in this week's edition of the journal "Nature."
Time again for our Website of the Week, when we showcase interesting and innovative online destinations. This time it's an example of how the power of the Internet can be harnessed to bring together resources and share information in the face of natural disasters and other emergencies.
LEIFSDOTTIR: "ReliefWeb is a website for providing timely and reliable information during crises to improve response and minimize human suffering."
Helga Leifsdottir is coordinator of Reliefweb.int, which is run by the U.N.'s Office for the Coordination of Humanitarian Affairs, known as OCHA. When there's a need for coordinated international response — an earthquake, perhaps, or drought — help can come from national governments, U.N. agencies, NGOs and private donors. Without coordination, good intentions may be squandered. Providing that coordination has been the aim of Reliefweb.int since it began 10 years ago.
LEIFSDOTTIR: "The overarching aim was to try to have a one-stop shop, where those who are working in this context of humanitarian assistance, would be able to go into one site and know what everyone was doing."
Although ReliefWeb is designed for those working in the humanitarian community, you don't have to be an aid worker to use it. In fact, at times of crisis, it provides current information from a broad range of on-the-ground sources.
LEIFSDOTTIR: "We are a broker of information from all of the sources, being it international or local NGOs, academia, international organizations, governments, etc., and of course the U.N. agencies. And we try to select carefully, from all sides, information on that particular emergency."
For example, take last month's deadly earthquake in Indonesia. Like many other disasters, it's been pushed out of the news by more recent developments, but you can still get daily updates from the Indonesian government, reports of the ongoing relief efforts in the region, maps and satellite images, detailed information about which governmental and non-governmental groups are helping, and so on. It's a real in-depth look at a crisis with a different perspective than you get in newspaper or broadcast reports.
That's typical of what's available on the U.N. website, ReliefWeb.int, or get the link from our site, voanews.com/ourworld.
MUSIC: John Lee Hooker, Jr.— "Stormy Monday"
And you're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
The annual meeting of the American Society of Gene Therapy wrapped up in Baltimore earlier this week.
Gene therapy is an exciting but still largely experimental field in which medical conditions are treated by actually changing the patient's DNA rather than using chemical medicines.
Mark Kay, president of the gene therapy society, says scientists are evaluating the treatment for use against a variety of conditions by supplying a missing gene, repairing a damaged gene, or silencing or turning off a gene.
KAY: "There are clinical trials that are currently ongoing for certain types of infectious disorders that cause pneumonia in children [and] age-related macular degeneration, using these methods to silence genes. And there will be clinical trials soon for HIV as well as hepetitis."
So gene therapy holds promise, not just for genetic disease — where you are essentially born with the condition — but also acquired disease, where external factors damage normal genetic function.
The corrective gene can be introduced into the body in a couple of different ways. Researchers are investigating ultra-tiny nano-particles, but so far the preferred method is generally through a deactivated virus.
KAY: "And the reason that this has caught so much attention is the fact that viruses have evolved over millions of years to be very effective vehicles at transferring genetic information into cells. So we as gene therapists take out the disease-causing genes of the virus and put in our theraputic genes to allow them to be delivered into our [patients'] cells."
Some of the most dramatic results of gene therapy have been seen in the case of so-called "bubble boy" disease, or more properly Severe Combined Immune Disorder, or SCID. Children with this genetic condition do not develop an immune system. Ordinary childhood diseases can kill them, and they are sometimes kept in a clear plastic isolation chamber to protect them from germs. Now, says Italian researcher Maria-Grazia Roncarolo, there are treatments.
RONCAROLO: "We have many therapeutic options today for these patients, from bone-marrow transplantation to gene therapy. Not for all of them, but definitely for some [of these diseases]. And there are now more than 60 patients in the world treated with gene therapy, and more than 30 are completely cured and can have a normal life thanks to gene therapy."
At a news briefing in conjunction with the gene therapy meeting, Dr. Roncarolo presented one of her star patients, a very cute four-year-old boy, Rafael Enrique Marcano. His father (Rafael Marcano) told reporters how the family's life had changed after his treatment.
MARCANO: "After four years we can say that the baby is cured. We want to say to the world that the gene therapy is true and it's safe. Before, our life is only doctors, only like in a bubble - the baby is in a bubble. But our life is changing, completely changing [to] a normal life."
That story is dramatic, but SCID is a very rare disease. Other researchers, including John Nemunaitis of the Mary Crowley Medical Research Center in Texas, are exploring the use of gene therapy for cancer, which he demonstrated, showing dramatic sets of before and after images
NEMUNAITIS: "What I've shown here are several patients who had cancer involving their lungs, and if you're not used to looking at these, these are called CT scans, and the black area is the inside of the lungs, and the white dots where the arrows are are where the cancer's at. But what I'm showing you here is the stage of the cancer and the stage after treatment — complete response, complete disappearance of all their cancer
WEST: "I'm Connie West. I believe those were my lungs that you saw just a moment ago. (laughter) I had my gene therapy in the fall of 2000. So as you can see, it's been six years. I'm in perfect health. I've just had a checkup with Dr. Nemunaitis recently. Without the gene therapy I guess I wouldn't be here talking to you today, and I can't say enough things about it. Thank you. (applause)"
Gene therapy tests involving humans have been underway since 1990. The death of an 18-year-old patient in one of those tests in 1999 made American regulators much more reluctant about approving human trials. Although gene therapy may hold vast promise, the U.S. National Cancer Institute highlights a number of challenges, including delivery of the injected genes to the right cells, and the fact that changes in genes will be passed on to future generations. Also, researchers say studies are hampered because they are testing gene therapies on only the very sickest patients, those who have exhausted all other treatments.
Still, the gene therapy society president, Mark Kay, says that one day he expects doctors to be using gene therapy, often in combination with conventional medicines, as a routine treatment for disease.
Even better than treating disease is preventing it.
U.S. regulators this week approved an expensive new vaccine against cervical cancer. Vaccines are great — that's how smallpox was eradicated — but low-tech strategies are important, too.
As we hear from VOA's Rosanne Skirble, scientists say many varieties of fruit have natural ingredients that may work to prevent diseases including heart disease and cancer.
SKIRBLE: The National Institutes of Health recommends people eat four to six helpings of fruits and vegetables a day. Public Health professor Gary Stoner at Ohio State University wants black raspberries to be top on your list. He's just published a study that found rats on a berry-rich diet had fewer malignant tumors than those not on the berry regimen.
STONER: "The reduction in tumor response to a carcinogen in the esophagus and the colon was between 40 and 60 percent. That is about as good as we have ever gotten with any pure compound."
SKIRBLE: Black raspberries contain vitamins, minerals and other valuable beneficial compounds known to prevent cancer in animals.
STONER: "We know now that the berries influenced the metabolism of carcinogens such that the end result is less genetic damage. And they do this by slowing the growth rate of pre-malignant pre-cancerous cells and they also stimulate these cells to die rather than grow."
SKIRBLE: And the berries inhibit formation of blood vessels in cancerous tumors which retard their growth.
Stoner says his research group has begun human trials with a focus on pre-cancerous lesions in the esophagus, mouth and colon, sites where the compounds can be absorbed most effectively.
SKIRBLE: Stoner says it is too early in the clinical trials to report any findings, however he hopes that the results will show the same protective effect found in the animal studies. The research appears in the current issue of the journal Nutrition and Cancer.
SKIRBLE: Chemist Darshan Kelly with the Western Human Nutrition Research Center in Davis, California says his work with cherries may give new hope to people who suffer arthritis and other inflammatory diseases.
For his research, healthy volunteers ate about 45 cherries a day for 28 days. During that time, Kelly's team studied specific biomarkers in their blood and urine related to inflammatory disease. By the end of the 4 weeks, researchers reported an 18–25 percent drop in the levels of the markers.
KELLY: "These markers are extremely important. Their concentrations are associated with the development of several chronic and inflammatory diseases."
SKIRBLE: Kelly says one of the most important biological markers is C-reactive protein or CRP, which is produced by the liver and increases rapidly during inflammation of the joints.
KELLY: "And, it is a significant risk factor for cardiovascular disease. Half of the people who have a heart attack don't have elevated cholesterol, but they [do] have elevated CRP. So, it is one of the most important risk factors for cardiovascular disease."
SKIRBLE: Kelly says the next step will be to reproduce the results and include people who are either overweight and at higher risk for a heart attack or already have elevated levels of CRP.
KELLY: "[With] one third of the population overweight or obese to reduce this in that population will be a big step forward to reduce the risk of cardiovascular disease and other inflammatory diseases."
SKIRBLE: The work appears in the Journal of Nutrition.
SKIRBLE: Keep drinking orange and grapefruit juice. Research from Texas A&M University finds that citrus may protect you from osteoporosis and other diseases. Co-author Bhimu Patil says rats that regularly consumed orange or grapefruit juice showed an increase in bone density and strength compared to those animals that did not drink juice.
PATIL: "We found both grapefruit juice and orange juice help increase the antioxidant activity, which in turn [promotes] bone density."
SKIRBLE: The antioxidants — vitamins, minerals and naturally occurring compounds — are thought to be effective in helping prevent cancer, heart disease and stroke. But Patil is not sure which compound in citrus is responsible for strengthening bones.
PATIL: "In citrus alone there are 400 active compounds. We need to go further in human beings to determine what happens [with the citrus compounds.]
SKIRBLE: Patil suspects the compound could be limonoid, which is the focus of several studies for its potential to prevent various human diseases. Patil says limonoids will be included in the next phase of his study, but notes that with at least 40 different types of the compound, it may take a while to identify the active agent. I'm Rosanne Skirble.
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Voice of America
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Faith Lapidus edits the show this week. Eva Nenicka is our 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.