How Autoimmune Diseases Attack the Body’s Defenses
A look at lupus and other disorders of the immune system. Transcript of radio broadcast:
13 April 2009
VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I’m Bob Doughty.
VOICE TWO:
And I’m Barbara Klein. This week, we talk about a sickness called lupus and other autoimmune diseases. Autoimmune diseases affect the immune system – the body’s natural defenses for fighting disease.
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VOICE ONE:
The immune system normally protects the body against foreign materials, such as viruses and bacteria. Autoimmune diseases result from a failure of the body’s own defenses against disease. The immune system loses its ability to tell the difference between foreign materials and its own cells. So, the body starts attacking its own organs and tissues.
VOICE TWO:
There are three kinds of lupus. Discoid lupus affects only the skin and can be identified by red marks on the face or neck. These marks on the skin can also be a sign of another form of lupus called systemic lupus. Systemic lupus can affect almost any organ or organ system in the body. When people talk about lupus, they usually mean the systemic form of the disease.
Some kinds of medicines can cause what is called drug-induced lupus. This form of lupus usually goes away when the patient stops using the medicines.
VOICE ONE:
High body temperature and pain in the elbows or knees are common signs of lupus. Other signs are red marks on the skin, feelings of extreme tiredness and lack of iron in the body.
At different times, the effects of lupus can be either mild or serious. The signs of the disease can come and go. This makes identifying the disease difficult. There is no single laboratory test to tell if someone has lupus. Many people with lupus also suffer from depression.
Lupus can also lead to other health problems. Women with lupus are at greater risk of developing heart disease. And between thirty and fifty percent of lupus patients will develop lupus-related kidney disease.
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VOICE TWO:
Lupus affects an estimated one million five hundred thousand people in the United States. Experts are not sure what causes lupus. However, the disease has been known to attack members of the same family. Recently, scientists identified genes they believe are linked to lupus. They hope studying these genes more closely could help in development of new treatments for the disease, and possibly a cure. Recent studies also support a theory that a combination of genes is linked to the development of lupus.
VOICE ONE:
Other suspected causes include antibiotic drugs, mental or physical tension, infections and hormones. In fact, hormones might explain why lupus affects women far more often then men. The Lupus Foundation of America says more than ninety percent of the people with lupus are women. Scientists do not know why women are more at risk than men. They think it might involve female hormones, like estrogen. Another idea is that it could involve the foreign cells left in a woman’s body after a pregnancy.
VOICE TWO:
There is currently no cure for lupus. Yet doctors have developed ways of treating the disease. Treatments are based on the condition and needs of each patient. No two individuals have the exact same problems. A treatment could include a combination of stress-reduction methods and drugs such as painkillers and steroids. Anti-malaria drugs also have been effective. Recent research also suggests that supervised exercise training can improve the quality of life for lupus patients.
It has been about forty years since the United States Food and Drug Administration approved a drug especially for treating lupus. Several companies are working to make drugs that can help lupus patients. Groups like the Lupus Foundation of America are working to increase public understanding of the disease.
Lupus can be life threatening if left untreated. Yet, many patients can lead a normal and healthy life if they follow their doctor’s advice. Patients must take their medicines and keep looking for side effects or new signs of the disease.
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VOICE ONE:
Lupus is not the only autoimmune disease. Doctors and scientists have identified at least eighty other diseases in which the body attacks its own organs and cells. Some of the diseases attack just one area of the body, like the skin, eyes or muscles. Others affect an organ system or even the whole body.
Some of the diseases are well known, such as rheumatoid arthritis, multiple sclerosis and type-one diabetes. Others are more difficult to identify and not as well known.
VOICE TWO:
For example, celiac disease is difficult to identify because the signs of the disease are so common. Patients may have low iron levels and experience stomach pain. The uncontrolled release of bodily wastes is also a problem.
Doctors might treat those problems and not know they are caused by celiac disease. Some people develop celiac disease after eating gluten, a protein found in all wheat products. It is not always clear that eating something as harmless as wheat can be bad for a person’s health. For some patients, it can be years before the problem is correctly identified.
VOICE ONE:
The United States National Institutes of Health says autoimmune diseases affect an estimated five to eight percent of the country’s population. Other groups disagree. For example, the American Autoimmune Related Disease Association says autoimmune diseases affect about fifty million Americans. That represents about one-sixth of the population.
The physical, emotional and financial cost of autoimmune diseases is huge. Most of those affected are women. While people of all ages are affected, women who are old enough to have children are especially at risk.
Some autoimmune diseases like lupus and scleroderma are more common in African-Americans. Diseases such as multiple sclerosis and type-one diabetes are more common among whites. Doctors do not yet know why this is true.
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VOICE TWO:
New drugs are being tested to help treat autoimmune diseases. Some drugs can be a problem because they suppress the immune system. This means the body is less able to defend itself against infections. As a result, the side effects of the drugs can be as dangerous as the disease itself.
Newer drugs attempt to suppress only one small part of the immune system, not all of it. For example, drugs like Enbrel and Remicade block tumor necrosis factor. This is a protein that causes inflammation, a physical reaction to infection, injury or other causes. These drugs have been useful in treating autoimmune diseases like rheumatoid arthritis, psoriasis, and Crohn’s disease. However, the drugs are very costly. They have also been found to increase the risk of cancer.
VOICE ONE:
Scientists continue searching for other methods of treatment. For example, some scientists hope to use stem cells to replace tissues damaged by disease. Stem cells have the ability to grow other cells, such as heart, nerve or brain cells.
Medical experts also are working together to improve the way autoimmune diseases are identified and treated. Less than ten years ago, the Johns Hopkins Autoimmune Disease Research Center was formed in the state of Maryland. The aim of the center is to bring together experts to improve the study of autoimmune diseases.
Private groups like the center show how important it is for scientists to share information about such diseases. Because each disease often affects different organs, many experts might be needed to treat the disorder. Experts need to know about the most recent research and technology. By sharing information about their patients, doctors also can learn from other cases.
VOICE TWO:
Government agencies are also working to increase knowledge about autoimmune diseases. In the United States, the National Institutes of Health created an autoimmune disease research plan in two thousand two. The plan urges agencies from different areas to work together.
Both private and government organizations are working to increase public understanding of such diseases. This can help individuals better understand what to do should they develop a health problem. At the same time, researchers continue working to help patients have a better quality of life.
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VOICE ONE:
This SCIENCE IN THE NEWS program written and produced by Brianna Blake. I’m Bob Doughty.
VOICE TWO:
And I’m Barbara Klein. Join us again next week for more news about science in Special English on the Voice of America.
Parkinson’s Disease: A Movement Disorder, and a Mystery of the Brain
New research and treatment for a disease mostly in older people. Transcript of radio broadcast:
06 April 2009
VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I’m Barbara Klein.
VOICE TWO:
And I’m Bob Doughty. Today we tell about the latest research and treatments for Parkinson’s disease.
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VOICE ONE:
In some patients, doctors place electrical devices into the brain to reduce the effects of Parkinson’s disease.
In some patients, doctors place electrical devices into the brain to reduce the effects of Parkinson’s disease
Parkinson’s is a disease of the central nervous system. It is a progressive disorder. It gets worse over time. The disease affects a small area of cells in the middle of the brain. This area is called the substantia nigra. The cells slowly lose their ability to produce a chemical called dopamine.
The decrease in the amount of dopamine can result in one or more general signs of Parkinson’s disease. These include shaking of the hands, arms and legs. They also include difficulty moving or keeping balanced while walking or standing. Also, there may be emotional changes, like feeling depressed or worried. The symptoms of Parkinson’s differ from person to person. They also differ in their intensity.
VOICE TWO:
The disease is named after James Parkinson. He was a British doctor who first described this condition in eighteen seventeen. Doctor Parkinson did not know what caused it. During the nineteen sixties, medical researchers discovered changes in the brains of people with the disease. These discoveries led to medicines to treat the effects of the disease. There is no cure for Parkinson’s and no way to prevent it. And doctors still are not sure about the cause.
Parkinson’s affects more than four million people around the world. It affects more than one million people in North America. Most are older adults.
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Most patients have what is called idiopathic Parkinson’s disease. Idiopathic means the cause is unknown. People who develop the disease often want to link it to something they can identify. This might be a medical operation or extreme emotional tension.
Yet many doctors reject this idea of a direct link to Parkinson’s. They point to other people who have similar experiences and do not develop the disease.
Still, doctors say it is possible that such events might cause symptoms of Parkinson’s to appear earlier than they would have.
Studies have found a link between the disease and some chemical products. Last year, an American study showed such a link between Parkinson’s and pesticides, like those used for killing insects. The study compared three hundred nineteen Parkinson’s patients to more than two hundred family members.
VOICE TWO:
Two years ago, a European study showed a link between pesticide use and Parkinson’s. This study also found that serious head injuries also increased a person’s risk. Scientists at Aberdeen University in Scotland collected information about more than nine hundred people with Parkinson’s or similar conditions. They compared this group to almost two thousand people without the disorder. All the people were asked about their use of pesticides, chemical fluids and metals like iron. The researchers also collected information about family history of the disease and head injuries.
Farm workers and others who said they often used pesticides had a forty-one percent greater risk of Parkinson’s than other people. The disease was also two and one-half times more common among people who had been knocked unconscious more than once in their lives. These people temporarily lost consciousness after suffering a blow to the head.
VOICE ONE:
Another area of study is family genetics. There are examples of members of a family having the disease. The National Institutes of Health in the United States says about fifteen percent of people with Parkinson’s have a family history of the disease. But most cases involve people with no such family history.
A few years ago, researchers completed what they called the first large map to show genetic links with Parkinson’s disease. The map identifies changes in genes that may increase the risk in some people.
VOICE TWO:
Recently, a gene-testing company announced plans for a large genetic study of Parkinson’s patients. The company, 23andme, was the idea of Ann Wojcicki.
She is the wife of Sergey Brin, who helped create the Internet search engine Google. He has a gene that increases his risk of developing Parkinson’s. His mother has the disease. The company is working with two not-for-profit groups. They hope to collect DNA from ten thousand Parkinson’s patients. The goal is to search for common genes that may cause the disease.
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VOICE ONE:
There is no cure for Parkinson’s disease. But improved treatments to ease the effects of the disease make it possible for many patients to live almost normal lives. People who have lost their ability to do many things are sometimes able to regain some of these abilities with treatment.
The most commonly used drug is levodopa. The National Institutes of Health says levodopa is a chemical found naturally in plants and animals. When it reaches the brain, levodopa is changed into dopamine, the chemical that is lacking in people with the disease.
VOICE TWO:
Levodopa helps ease the symptoms of Parkinson’s. But it does not prevent more changes in the brain that are caused by the disease. Long-term use can produce unwanted effects in some people. These side effects include feeling sick to the stomach.
To prevent this from happening, levodopa can be combined with other substances, like carbidopa. The National Institutes of Health says carbidopa delays the changes in levodopa until it reaches the brain.
Other drugs used to treat Parkinson’s disease act like dopamine. They produce reactions in the nerve cells in the brain. They can be given alone or in combination with levodopa. Many of the possible side effects are similar to those linked with the use of levodopa. They include sleepiness, feeling sick or having bad dreams.
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VOICE ONE:
An operation called deep-brain stimulation also is used to treat Parkinson’s disease. Doctors place small electrical devices deep in the brain. The devices are connected to a piece of equipment called a pulse generator.
Deep brain stimulation can reduce the need for levodopa and other drugs. It also helps to reduce symptoms such as shaking and slowness of movement. Recently, a report in Science magazine showed how deep-brain stimulation works. It found that the treatment affects neural wires called axons.
The researchers were from Stanford University in California. They used light-sensitive molecules to turn on and off nerve cells in the deep brain structure of mice. Nothing happened when they turned on the light in cells in an area of the brain called the subthalamic nucleus. But bursts of electricity on the axons improved movement in the animals.
VOICE TWO:
A separate study found that a less invasive treatment might reduce the symptoms of Parkinson’s. It showed that a treatment called dorsal column stimulation could re-establish movement in rodents with Parkinson’s-like problems. In the study, researchers fired bursts of electricity at the animals’ spinal cords. Romulo Fuentes of Duke University in North Carolina led the researchers. He noted that doctors already use spinal cord stimulation in people to help reduce long-lasting pain.
VOICE ONE:
Scientists are also exploring other experimental treatments. In March, President Obama ended restrictions on the use of federal money for research using human embryonic stem cells. Stem cells from very early embryos are able to grow into any tissue in the body. Scientists say such cells might be able to cure or treat diseases like Parkinson’s. But opponents say stem cell experiments are wrong because human embryos are destroyed. They say this is just like destroying a human life.
VOICE TWO:
American actor Michael J. Fox has had Parkinson’s disease for eighteen years. But unlike most patients, he got the disease as a young man. He is forty-seven now and has many symptoms of the disease. But Fox still acts on television, writes books and is an activist for Parkinson’s. The Michael J. Fox Foundation has raised more than one hundred forty-two million dollars to fund research for better treatments. Michael J. Fox says he is sure that a cure for Parkinson’s disease will be found in the future.
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VOICE ONE:
This SCIENCE IN THE NEWS was written by George Grow. Our producer was Brianna Blake. I’m Barbara Klein.
VOICE TWO:
And I’m Bob Doughty. Transcripts, MP3s and podcasts of our programs are at voaspecialenglish.com. Join us again next week for more news about science in Special English on the Voice of America.
Ancient Footprints Let Experts Step Back in Time
Also: A study finds that being hopeful about future events might help you stay healthy and live longer. And a mysterious sickness is reducing bat populations in the northeastern U.S. Transcript of radio broadcast:
30 March 2009
Correction attached
VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I’m Barbara Klein.
VOICE TWO:
And I’m Bob Doughty. This week, we will tell about evidence of early human ancestors. We also will tell about the health effects of hopeful feelings. And, we will tell about disappearing bat populations in the northeastern United States.
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VOICE ONE:
An international research team has discovered markings made by the ancestors of modern human beings more than one million years ago. The discovery is exciting because it shows the shape of the feet and walking method of the human ancestors.
Rutgers University Professor Jack Harris led the researchers and students who uncovered the marks during three years of digging. They found the ancient footprints near the village of Ileret in northern Kenya. A report about their findings was published last month in Science magazine.
VOICE TWO:
Early humans made the footprints as they walked on volcanic ash and soil that turned to rock over time. The team found two sets of prints in separate levels of rock that are about one million five hundred thousand years old.
The scientists say the prints were left by one of two human ancestors: either Homo erectus or Homo ergaster. However, many experts do not recognize a difference between the two. Homo erectus is the more commonly used name.
VOICE ONE:
Surprisingly, the footprints look much like those you would find on a sandy coastline today. In their report, the team said the discovery provides the oldest evidence of a foot structure that is generally the same as a modern human’s.
The prints show how the big toe of Homo erectus is close to the other toes. In earlier species, the big toe is separated widely from the other toes — as in the foot structure of apes. No Homo erectus foot bones have ever been found. This makes the well-preserved footprints especially valuable.
VOICE TWO:
Scientists have also learned how Homo erectus walked from the prints. Researcher Matthew Bennett of Bournemouth University used laser technology to make digital images of the footprints. These images suggest that Homo erectus walked by touching the ground first with the back of the foot and pushing off with the front — just as we do.
The researchers could even estimate the height of the ancient individuals. One was only about a meter tall. It is believed to have been a child. The others were about the average height of modern human adults.
VOICE ONE:
The findings provide more evidence that human ancestors were able to travel long distances. Homo erectus may have left Africa for other parts of the world as early as one million eight hundred years ago.
This is only the second time that early human footprints have been found. In nineteen seventy-eight, British anthropologist Mary Leaky discovered the prints of a possible human ancestor at Laetoli, Tanzania. They belonged to Australopithicus afarensis, a much earlier and smaller human-like creature that walked on two feet.
VOICE TWO:
Professor Harris says his team not only found footprints, but also many animal tracks in the rock. These include markings of hoofed animals that Homo erectus may have hunted for food. Other tracks belonged to meat-eaters. Such creatures were competitors or even threats to the early humans.
The footprints found in Kenya have let scientists step back in time to find new details about our distant ancestors and their environment.
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VOICE ONE:
An American study has shown that being hopeful about future events might help you stay healthy and live longer. The study found links between people’s beliefs and their risks of cancer-related death, heart disease and early death.
Researchers studied one hundred thousand women during an eight-year period, beginning in nineteen ninety-four. All of the women were fifty years of age or older. The study was part of the Women’s Health Initiative, a continuing study organized by the National Institutes of Health. The findings were presented earlier this month at a meeting of the American Psychosomatic Society.
VOICE TWO:
For the study, the women were asked questions that measured their beliefs or ideas about the future. The researchers attempted to identify each woman’s personality eight years after gathering the information.
The study found that the hopeful individuals were fourteen percent less likely than other women to have died from any cause. The hopeful women were also thirty percent less likely to have died from heart disease after the eight years.
VOICE ONE:
Hilary Trindle was the lead writer of the report. She is an assistant professor of medicine at the University of Pittsburgh in Pennsylvania. She says the study confirms earlier research that also linked optimistic feelings to longer life. However, this study is different from earlier research on the subject.
The researchers also gathered information about people’s education, financial earnings, physical activity and use of alcoholic drinks or cigarettes. Independent of those things, the findings still showed that optimists had less of a chance of dying during the eight-year period.
VOICE TWO:
Some women who answered the study’s questions were found to be cynically hostile, or highly untrusting of others. These women were sixteen percent more likely to die than the others. They also were twenty-three percent more likely to die of cancer.
The study also found that women who were not optimistic were more likely to smoke, have high blood pressure or diabetes. They were also more likely not to exercise.
Professor Tindle says the study did not confirm whether optimism leads to healthier choices, or if it actually affected a person’s physical health. She says the study does not prove that negative emotions or distrust lead to bad health effects, and shorter life. Yet there does appear to be a link between the two. More research is needed to discover the exact reasons for the findings.
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VOICE ONE:
In recent years, biologists have observed a sharp drop in bat populations in the northeastern United States. The biologists believe the drop has resulted from a mysterious sickness called white nose syndrome.
Little is known about the sickness. It is called white nose syndrome because of a white-colored fungus found on the faces of affected bats. The fungus seems to grow in cold weather. The affected animals were first observed in two thousand seven in New York State.
Scientists believe the disease causes bats to awaken early from their hibernation or yearly rest period. The scientists say the bats then leave their resting places in search of food during the winter when the insects they eat are not available. Without a food supply, the bats starve to death.
VOICE TWO:
Wildlife officials say white nose syndrome is not a direct threat to other animals or human beings. However, the bats’ continuing disappearance could have a far-reaching effect on the environment.
Bats have survived for about fifty million years. They eat large amounts of insects, up to twenty-five percent of their body weight in one night’s feeding. If fewer bats are available to eat the insects, farmers will have to use more insect-killing chemical products to protect their crops. Diseases that are spread by insects could also become more common.
VOICE ONE:
Cases of white nose syndrome have been confirmed in New York, New Jersey, Connecticut, Vermont, Massachusetts and Pennsylvania. It is difficult for scientists to know the exact number of bats that have died as a result of white nose syndrome. However, some estimate that hundreds of thousands of bats have already disappeared.
The United States Geological Survey says the disease has affected six bat species. They include little brown bats, northern bats, tricolored bats, Indiana bats, small-footed myotis and big brown bats.
Biologists are currently studying possible ways to keep the disease from spreading. Tests are needed to guarantee a plan that will be effective.
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VOICE TWO:
This SCIENCE IN THE NEWS program was written by Mario Ritter and Brianna Blake, who was also our producer. I’m Bob Doughty.
VOICE ONE:
And I’m Barbara Klein. Read and listen to our programs at voaspecialenglish.com. Join us again next week for more news about science in Special English on the Voice of America.
Correction: This story should have said that Homo erectus may have left Africa as early as one million eight hundred thousand years ago, not one million eight hundred years ago.
