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RESEARCH ETHICS By Kristie Stoick, M.P.H., and John J. Pippin, M.D., F.A.C.C.
Microdosing Proves Superior to Animal Drug Tests
Preliminary data released in June as part of a European Union partnership project provides more evidence that microdosing will improve the safety assessment of drugs before clinical testing in a variety of different compounds.
Microdosing is a preclinical safety testing technique for pharmaceuticals that involves highly controlled trials of new drugs in humans, using ultralow doses tagged with a label. The technique allows researchers to get accurate information on the movement of the drug as it is absorbed and metabolized in the human body, which offers a much more accurate picture than such studies in animals. The ultralow doses ensure the trials will be safe.
Barnes, K. New data adds weight to case for microdosing. Outsourcing-Pharma.com Web site. June 24, 2008. Available at: http://www.outsourcing-pharma.com/news/ng.asp?n=86103-eumapp-xceleron-microdosing-preclinical-phase-i. Accessed August 17, 2008.
Draize Test Alternatives Accepted by Regulatory Authorities
The Environmental Protection Agency, Food and Drug Administration, Department of Transportation, and several other government agencies recently approved the first alternatives to the infamous Draize rabbit eye test. The test, which has been used since the 1940s, involves applying chemicals to rabbits’ eyes for four hours to test for corrosive or irritating damage.
A wide variety of replacements have been developed, including several test-tube methods. The newly approved tests use cow or chicken eyes from slaughterhouses and, while not completely animal-free, represent an important refinement from the use of live rabbits.
The tests were approved as part of a tiered strategy in the United States. Companies will now use this test first, and if the chemical is found to be corrosive, no further testing will take place. Chemicals not shown to be corrosive must still be tested in rabbits to double-check negative results and for irritation. While this is not a complete replacement, the most harmful chemicals will not be tested on rabbits, and the tiered strategy will reduce the number of rabbits used for eye toxicity testing by about 10 percent.
Progress in Europe has been considerably better. The tests were approved last year in Europe to fully replace rabbits for both positive and negative results.
Tests for eye irritation and tests that use no animal parts, but instead use human corneal tissue grown in a laboratory, are available but still require regulatory acceptance.
National Institutes of Health Press Release. June 23, 2008. Available at: http://iccvam.niehs.nih.gov/methods/ocutox/ivocutox/transmit/ OcularfinalJune23.pdf. Accessed August 17, 2008.
New Zealand Researchers Develop Award-Winning Nonanimal Toxin Test
A research team at New Zealand’s AgResearch Biomembrane Laboratory has developed the world’s first nonanimal test to identify toxins in drinking water or shellfish.
Mice are currently used in tests for neurotoxic chemicals from algal blooms. The toxins can cause sickness, pain, and paralysis, and at least half of the mice used for each test die.
The new method uses a membrane-receptor system isolated from human muscle tissue and measures electrical current across membranes that have been exposed to samples of water. Test results are more directly relevant to the effect being sought.
“It’s a physical reaction that enables us to predict actual toxicity to humans,” says Jim Dunlop, part of the laboratory team.
The new test is faster and cheaper than animal methods. For developing the test, the team won an award sponsored by the Health Research Council of New Zealand and has received funding for further commercial development.
AgResearch. New toxicity test could replace animal testing. In Touch. March 2008;36:7. Available at: http://www.agresearch.co.nz/publications/intouch/AgResearch_News_Mar2008.pdf. Accessed August 17, 2008.
NUTRITION By Dulcie Ward, R.D., and Susan Levin, M.S., R.D.
Overweight Teens Headed for Adult Health Problems
In an extensive long-term study, people who were obese or overweight in adolescence were found to be three to four times as likely to have died of heart disease by middle age as compared with their thinner peers, according to a study in the American Journal of Epidemiology. More than 200,000 Norwegian teens were measured for body mass index (BMI) as part of a compulsory national health survey and followed for an average of 34.9 years. Overweight teens were two to three times more likely to die from colon cancer or respiratory disease later in life. Women in the highest BMI category were at increased risk of death from cervical cancer, and both sexes were at increased risk for sudden death.
Bjørge T, Engeland A, Tverdal A, Smith GD. Body mass index in adolescence in relation to cause-specific mortality: a follow-up of 230,000 Norwegian adolescents. Am J Epidemiol. 2008;168:30-37.
90 Percent of Americans Could Be Overweight or Obese by 2030
If steady increases in the prevalence of overweight and obesity continue through the year 2030, 86.3 percent of adults will be overweight or obese, the prevalence of childhood overweight will double, and 1 of every 6 health care dollars will be used to pay for overweight and obesity-related costs.
Researchers at the Johns Hopkins Bloomberg School of Public Health based these projections on trends from the National Health and Nutrition Examination Study data collected over the past three decades. By 2030, the prevalence of overweight among African-American women and Mexican-American men will be 96.9 percent and 91.1 percent, respectively.
The problem is not primarily genetic. Rather, rapidly changing eating habits are expanding American waistlines.
Wang Y, Beydoun M, Liang L, Caballero B, Kumanyika S. Will all Americans become overweight or obese? Estimating the progression and cost of the US obesity epidemic. Obesity advance online publication, July 24, 2008 (DOI 10.1038/sj.oby.2008.351)
Fiber Reduces Risk of a Lethal Pregnancy Complication
Fiber—or plant roughage—is found in vegetables, fruits, beans, and grains. A new study shows that some of its benefits may be unexpected. According to the study, fiber consumption during the first three months of pregnancy can reduce the risk of developing preeclampsia, a condition with potentially lethal complications. Preeclampsia, characterized by high blood pressure and protein in the urine, develops during and immediately after pregnancy and can affect both women and their infants.
Researchers looked at the diets of more than 1,500 pregnant women in Washington state. Women who ate more than 21 grams of fiber per day were at 67 percent less risk than those who ate less than 12 grams of fiber per day. The study also found that women who ate more fiber consumed more fruits and vegetables, more vitamin C, and less fat. They also had higher levels of HDL (the good cholesterol), and lower plasma triglyceride levels—two key factors in preventing cardiovascular disease.
Qiu C, Coughlin KB, Frederick IO, Sorensen TK, Williams MA. Dietary fiber intake in early pregnancy and risk of subsequent preeclampsia. Am J of Hypertens. 2008;21:903-909.