Health Highlights: Jan. 1, 2007
Scientists Develop Genetically Engineered Cattle Without Mad-Cow Prion Obstetrics Group Recommends Expanding Down Syndrome Tests Heart Disease Still Plagues Southern States Pet Owners Aren't Picture of Health: Study
Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
Scientists Develop Genetically Engineered Cattle Without Mad-Cow Prion
Scientists have used genetic engineering techniques to produce the first cattle biologically incapable of getting mad cow disease.
The breakthrough, published online in the journal Nature Biotechnology Sunday, was done by Hematech Inc., a unit of Japan's Kirin Brewery Co., and the U.S. Department of Agriculture, Bloomberg News reported.
Researchers found that cows bred without the so-called prion protein were healthy at age 20 months and their tissue showed signs of resistance to mad-cow disease, a brain-wasting illness that has been linked to almost 200 human deaths in the past decade.
The findings suggest that genetic modifications can protect cattle from mad-cow disease, potentially eradicating the threat to livestock and the people who eat them or use products made from them. James Robl, president of Hematech, told Bloomberg that the company hopes to sell its research to agriculture or industry groups.
Knocking out the gene for mad-cow disease, also called bovine spongiform encephalopathy, is a "side project'' for Hematech's efforts to develop human medicines in cows, Robl said. Kirin, Japan's largest beverage maker, announced in May 2004 that it planned to produce drugs based on human antibodies grown in cattle.
For the study, scientists bred a dozen prion-free bulls and then tested a sample of their tissue at age 20 months by mixing it in a lab with tissue from an animal that had died of mad-cow disease. The altered cows' tissue didn't become contaminated, while tissue from conventional cows did.
Robl said the final verdict on mad-cow immunity will come in the next year after scientists complete a study injecting contaminated tissue directly into the brains of live animals.
Obstetrics Group Recommends Expanding Down Syndrome Tests
Experts at the American College of Obstetricians and Gynecologists (ACOG) are recommending that maternal age no longer be a major criterium for testing pregnant women for Down syndrome. Currently, doctors don't routinely order the test for women under 35, due to risks linked to invasive amniocentesis, the Associated Press reported.
However, the advent of accurate, less invasive testing technologies means that younger women should now be screened for the birth defect, experts say. The new ACOG guidelines are published in the January issue of Obstetrics & Gynecology.
About 1 in every 800 babies is born with Down syndrome, which is caused by an extra chromosome. Risks rise gradually with maternal age: about one in every 1,200 pregnancies in women aged 25 are affected by Down syndrome compared to one in every 300 pregnancies for women aged 35.
New non-invasive tests -- such as a combination of first-trimester blood screening and detailed ultrasound of the fetal neck -- are more than 80 percent accurate in spotting Down syndrome, with very few false-positives, the AP reported. Routine use in all pregnant women could detect more cases much earlier, the ACOG experts say.
"The new recommendation makes a lot of sense," Dr. Nancy Green of the March of Dimes told the AP. "Maternal age no longer plays such an important role because the screening is better."
Heart Disease Still Plagues Southern States
Heart disease hits Americans who live in southern states harder than residents of other regions of the country, according to the latest annual survey of cardiovascular disease in the United States.
Cardiovascular disease accounted for more than one-third of all deaths nationwide in 2004, the most recent year for which statistics are available.
Mississippi had the highest fatality rate from cardiovascular disease and coronary heart disease, with nearly 406 deaths per 100,000 people. Oklahoma was next, with nearly 401 deaths per 100,000 people; Alabama, with 378 deaths; Tennessee, with nearly 374 deaths per 100,000; and West Virginia, with 373 deaths per 1,000 people, the Associated Press reported.
What's more, twice as many angioplasties were performed in southern states, compared to other regions of the country. There were similar trends in bypass surgery, open-heart surgeries and pacemaker implants, the AP said.
The yearly survey is conducted by the American Heart Association, which released the findings Friday, ahead of a January publication of the survey in its journal Circulation.
Wayne Rosamond, an epidemiologist at the University of North Carolina and chairman of the American Heart Association's Statistics Committee, said studies are under way to determine the reasons behind the regional differences, the news service said.
"What drives those shifts is not really well understood," he said. "There are a lot of things going on that are good, particularly on the prevention side."
Some of those encouraging signs, he said, are a drop in smoking rates among young people and a growing awareness of heart disease among women.
Pet Owners Aren't Picture of Health: Study
Pet owners tend to be in pretty good shape, given all the exercise they get walking their animals, right?
Wrong, says a new Finnish study, which found that pet owners -- particularly dog owners -- are actually less healthy than people who don't own pets.
Researchers at the University of Turku studied more than 21,000 working-aged people. They found that pet owners smoked slightly more often and exercised less often than those who didn't have pets, the researchers reported in the current online issue of PloS One.
Dog owners exercised more than those without dogs, but this did not have an effect on their body mass index, the researchers found, according to the Canadian Broadcasting Corporation.
Pet ownership was most common among people aged 40 or older, who tend to settle down as couples in single-family homes. Pet owners were also slightly more likely to have a low social standing or education, the CBC said.
"Pet owners had a slightly higher BMI (body mass index) than the rest, which indicates that people having a pet (particularly a dog) could use some exercise," the researchers concluded.
At Atlantic Veterinary College at the University of Prince Edward Island in Canada, researchers are testing whether fitting overweight dogs with pedometers will motivate dog owners to get more exercise for their pets and themselves, the CBC said.