Stories tagged health

Nov
10
2005

Dr. Arthur Aufderheide, a teacher at the University of Minnesota at Duluth, helped to found the science of paleopathology-the study of ancient diseases. He autopsies mummies, salvaging and studying mummy organs from all over the world.

Aufderheide uses his collection of more than 6,000 samples of mummy tissue to identify the diseases that plagued ancient populations. His work helps to show where diseases evolved and how they spread, and may even help to cure modern ailments.

Traces of ancient diseases

Paleopathologists value tissue samples from mummies because they may still show signs of illnesses. Mummy eyes are usually well preserved, and can provide evidence of eye diseases as well as chronic conditions such as diabetes, high blood pressure, some kinds of cancer, nutritional deficiencies, and fetal alcohol syndrome. Scientists can also diagnose illnesses caused by bacteria and parasites-such as tuberculosis, malaria, and Chagas' disease-from mummy tissues.

Learning from the dead

Until very recently, paleopathologists looked at individual mummies and wrote case reports: they could sometimes prove the presence or absence of a disease in one person, but they couldn't test big hypotheses or compare modern populations to ancient ones.

Aufderheide, on the other hand, has tissue samples from 283 mummies from Peruvian and Andean coastal South America at different time periods. Today, many people in those areas suffer from Chagas' disease-an incurable illness caused by a parasite. Aufderheide and colleagues used DNA analysis to search for signs of the disease in the mummies. Because they had such a large number of samples, they were able to compare the mummies to modern-day populations and generate statistically significant results. They found the parasites in 41% of the samples, and the percentage was the same for both sexes, all ages, and all time periods. Their results suggest that people in coastal South America have been exposed to Chagas' disease for 9,000 years.

Oct
10
2005

It's in the news. People are dying from a relative of the 1918 Influenza virus half a world away, and scientists fear it may be the next pandemic. Sounds like science fiction, or the latest box-office smash, right? Unfortunately, it's real, and is happening right now.

chickens: (Photo courtesy Laura Hadden)
chickens: (Photo courtesy Laura Hadden)

In Southeast Asia, a virus known as avian influenza or avian flu has the potential to spread and kill humans with terrifying speed. Avian flu is also known as H5N1 for the proteins that bind, infect, and destroy its host cell to thrive. Chickens can die within hours of exposure, swollen and hemorrhaging, but it is just as lethal to mammals from lab mice to tigers. The virus has decimated bird flocks in 11 countries mostly in Asia, and has killed 62 people (half the known cases) to date, with highest fatalities occurring in Vietnam, Cambodia, and Thailand. So far, nearly all people infected contracted the sickness directly from infected poultry and at this point there is no confirmed evidence of efficient human-to-human transmission. However, health authorities fear that the H5N1 strain will likely mutate into a pathogen easily passed between humans if it continues to persist in the environment. If that happens, and authorities believe it's only a matter of time, the world could face a catastrophic pandemic.

Many health organizations and governments are stockpiling a drug (Tamiflu) to protect against this potential pandemic, but scientists are reporting that a strain of H5N1 avian flu virus is showing resistance to the antiviral drug. Scientists are working to avoid this disaster by detecting changes in the evolving H5N1 virus. As a first step, scientists have rebuilt the 1918 flu-a disease that killed as many as 50 million people-from pieces of genetic material retrieved from the lungs of people who died 87 years ago. Gene-swapping experiments are starting to give scientists some clues in the lab. When small substitutions were made, the reconstructed virus could no longer replicate in the lungs of mice, kill animals, or attach itself to human lung cells.

So far H5N1 has not yet learned the trick of racing from person to person like the ordinary flu and maybe never will. Nevertheless, experts fear that the risk could materialize and are urging the world to prepare for the worst.

United Nations Food and Agriculture Program

NPR Health and Science Report

Aug
22
2005

It's older than the plague, typhoid fever, or malaria. It's claimed the lives of literary greats John Keats, Emily Bronte, and Franz Kafka, and kills more than three million people around the world each year by attacking the lungs and producing symptoms like coughing, loss of appetite, fever, and night sweats. Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, is also re-emerging in areas like Eastern Europe, southeast Asia, and sub-Saharan Africa, where HIV is on the rise. Scientists now believe that TB may actually date back as far as three-million years, with current strains descended from a more ancient bacterial species that emerged in Africa. "Tuberculosis. . . might have affected early hominids," says researcher Veronique Vincent of the Institut Pasteur in Paris. Up until this point, scientists believed that TB arose a few tens of thousands of years ago and spread around the world. However, molecular analysis of a strain of TB from East Africa suggests that the disease is much, much older. Researchers hope this information will aid in the development of new treatments; Mycobacterium tuberculosis is rapidly growing resistant to the drugs currently used to treat it.

Aug
05
2005

A study based on the 1959-61 famine in China has shown that babies born into starvation have more than double the risk of developing schizophrenia later in life.

Schizophrenia occurs worldwide in about 1% of the population. For individuals who receive poor fetal nutrition, the risk may be as much as 2.3%.

Researchers in Australia and China studied the incidence of schizophrenia among those born before, during and after the
1959-61 period of famine in the Chinese province of Anhui. Their findings, that rates of schizophrenia jumped 2.3 times, are consistent with a Dutch study that uncovered the same increase for children born during the war-time famine in Holland, from 1944-45. The Chinese study, however, is statistically significant because Anhui's population of nearly 65 million inhabitants is so large.

Scientists still don't understand what causes the increase. "We don't yet know what the component of the nutritional deficiency is, or what the biological mechanism is that takes place in the brain resulting from the deficiency, although pre-natal folate deficiency has been implicated in neural defects in the past," says Feng Zhang at Aberdeen University.

The question remains whether the cause is general lack of nutrition in the womb or the lack of one specific nutrient. It's possible that the gene for schizophrenia is switched "on" or "off" when a chemical group is taken away from an individual's DNA. For example, the lack of folate could interfere with DNA and increase the expression of the gene for schizophrenia.

This may explain why the mental illness survives from generation-to-generation around the world, says Zhang: "There may be an evolutionary advantage for schizophrenia genes during famine."

Schizophrenia remains one of the world's most mysterious mental disorders, difficult to diagnose and sucessfully treat.

May
11
2005

Biotherapy is the use of animals to diagnose or treat diseases or to assist the ill or impaired.

A leech: it does a body good?
A leech: it does a body good?Courtesy Michael Jefferies

One biotherapy that many of us are familiar with is seeing eye dogs. A less common biotherapy is the use of household pets, such as dogs or cats, in long term care facilities to improve the mood of and provide companionship for the people living there.

But other, less familiar animals have been put to medicinal purposes, too. Leeches have been used for thousands of years for various "medical" uses, and have recently been approved as a medical device by the U.S. Food and Drug Administration (FDA). Doctors use leeches to restore blood circulation after cosmetic or reconstructive surgery.

Maggot therapy has also staged a comeback. Doctors use maggots to treat and clean problematic wounds.

Honey bee therapy (or apitherapy), is the use of honey bee venom—which contains anti-inflammatory substances—to relieve pain in patients suffering from rheumatoid arthritis. Apitherapy can also help treat some neurological syndromes, such as multiple sclerosis.

What do you think of biotherapy? How would you react if a doctor told you that they were going to treat you with leeches or maggots?

Want to learn more about biotherapy? The BTER Foundation is an organization dedicated to supporting patient care, education, and research in biotherapy and symbiotic medicine. The International Biotherapy Society is another organization devoted to supporting the use and understanding of living organisms in the treatment of human illnesses.

Mar
18
2005

Scientists at the annual meeting of the American Chemical Society announced this week that Hispanic herbal teas may be better for you than the much-touted green tea.

Researchers looked at three types of Hispanic teas: ardisia, roselle (hibiscus), and mate (MAH-tay). Mate, as it turns out, is especially high in antioxidants, which help the body protect itself from the damaging effects of oxygen. A few mate brands were higher in antioxidants than green tea, which has been widely publicized for its medicinal qualities.

Elvira de Mejia, Assistant Professor of Food and Nutrition at the University of Illiois at Urbana-Champaign, suggests that people interested in getting the health effects of mate drink three or four cups a day.

Are you likely to change your beverage habits based on information like this? Do you choose foods because they're healthy, because they're what you're used to, or because you like the taste? What other kinds of food/nutrition stories would you like to see here?

Mar
14
2005

As the Pioneer Press reports (and as was noted here earlier), life expectancy in the US continues to rise. The average American can now expect to live 77.6 years.

But how far can we push it? 100 years? 120? The Sunday Times of London offers a survey of current research and suggests that, at the rate medical science is advancing, it's possible that some children alive today may live a thousand years or more!

Mar
09
2005

A new study published in The New England Journal of Medicine shows that low doses of aspirin do not prevent first heart attacks in women under 65, as they do in men.

Earlier research, which focused mostly or entirely on men, indicated that aspirin prevents heart attacks. But the 10-year Women's Health Study, which followed 40,000 women, showed that aspirin does not prevent heart attacks in women. However, it does prevent strokes caused by blood clots, a benefit that has not been conclusively proven in men.

Women in the control group had the same number of heart attacks as the women in the aspirin group. But the number of strokes in the aspirin group was 17% lower. And the aspirin takers had a whopping 24% lower risk of ischemic stroke—the most common kind, caused by a blood clot in an artery leading to the brain. However, the risk of hemorrhagic stroke—caused by bleeding—was slightly higher in the aspirin group. (This was expected, because aspirin reduces blood's ability to clot.)

Both ischemic strokes and heart attacks are caused by blood clots in arteries, so it isn't clear why aspirin only protects women against strokes. The explanation may have something to do with the size of the blood vessels that lead to the brain, which are smaller than those leading to the heart, but no one knows yet for sure.

Because aspirin therapy increases the risk of bleeding, doctors don't currently advise men or women with no risk of heart disease to take aspirin as a preventive measure. Women with risk factors for heart disease (they're over 65, they smoke, have high blood pressure, are diabetic, or have a family history of cardiovascular problems) are often told to take a baby aspirin every day. That probably won't change.

But now doctors can fine-tune the way they manage patients with cardiovascular risk, knowing that women under 65 are more vulnerable to certain kinds of stroke.

You can read the New York Times article about the study here

You can read an abstract of the article in The New England Journal of Medicine here

What do you think about research that shows that some drugs affect women differently than men? Should drug studies have to include equal numbers of men and women? Or should they look at men and women separately? How about different ethnic groups? Or children?

Feb
24
2005

"Mad cow disease"-also known as bovine spongiform encephalopathy (BSE)-is a fatal brain disorder in cows. It's spread by contact with brain or other nervous-system tissue from an animal with the disease. An animal can be infected but not have any symptoms for years. But once the disease is active, it kills brain cells, leaving large, spongy holes. It also causes large clumps of abnormal proteins in the brain and quickly kills the victim.

Scientists still don't know for sure what causes mad cow disease. But the most likely theory is that abnormal proteins called prions (PREE-ons) damage nerve cells, causing loss of brain function and eventual death.

You can read more about prions and how scientists think they might cause mad cow disease:
click here

Scientists think mad cow disease came from a similar disease in sheep called scrapie. We used to feed cows meat and bone meal-from other cows, but also animals such as sheep-leftover after processing for human consumption. Cows ate food contaminated with scrapie and developed BSE. At the time, people thought that neither scrapie nor BSE affected us, so meat from BSE-infected cows got into the human food supply. People who ate the infected meat-probably hamburger or other processed meats-developed a disease similar to the cows'.

You can find out a lot more about mad cow disease and its human manifestation:
click here

The US government has made some rules to try and protect people here from the disease. It has banned the import of cud-chewing animals (cows, sheep, goats) and products made from them from Europe. It prohibits the use of any mammal products in food for cows. Cows with unidentified neurological disorders cannot be eaten. Drug companies can't use animal tissues from countries with mad cow disease when they make vaccines or other products. And people who spent more than six months in the UK (where the mad cow disease epidemic was first identified) between 1980 and 1986 are not allowed to donate blood.

Do the new rules make you feel safer about eating meat? Have you changed any of your eating habits since mad cow reports came out in the media?

Feb
04
2005

Researchers at the Mayo Clinic have found a way to use measles to fight cancer.

Viruses are parasites. To reproduce, they seek out sites on a healthy cell, get inside, and then take over the host's cellular machinery. For years, researchers dreamed of using viruses to hijack cancer cells.

The Mayo team knew that measles kills most cancer cells, too. But to use the virus as an anti-cancer treatment, they had to change the virus so it wouldn't attack healthy cells. They eliminated the virus's ability to bind to its natural receptors, and retargeted it to zero in on ovarian cancer cells.

In lab animals implanted with human cancer cells, the virus hunted down and destroyed only infected cells. Clinical trials on patients with ovarian cancer began last summer, but it will be at least three years before the treatment is approved for use in hospitals.