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Alternatives to Animal Research
New Microchip Device Replaces Animals in Toxicity Tests
Scientists are well aware that different species respond to chemical toxins and pharmaceuticals very differently–so what’s safe for a mouse may be highly toxic for a human or vice versa. Scientists at Hurel Corporation in Beverly Hills, California, and Cornell University in Ithaca, New York, hope to avoid these variables with a new microchip system dubbed the Hurel cell. The miniature device consists of a network of interconnected reservoirs mimicking the organ systems of a living being.
Researchers can place lung, liver, fat, gastric, or heart cells inside these various reservoirs; add a particular drug; and then quickly evaluate how the chemical is absorbed, distributed, metabolized, and finally excreted. The Hurel cell enables scientists to see how a specific drug might affect multiple organs simultaneously in a human.
Finding important human effects early in the drug or chemical development process can not only weed out poor or toxic candidates, but also can give researchers an idea of what effects to look for in future clinical studies. As the company’s tag line says, Hurel is “Human-Relevant.”
Additional information on Hurel is available at www.hurelcorp.com.
Viravaidya K, Sin A, Shuler ML. Development of a microscale cell culture analog to probe naphthalene toxicity. Biotechnol Prog. 2004;20:316-323.
Columbia University Puts the Brain Online
Columbia University’s Department of Neuroscience has established a new Web site atlas, mapping neurotransmitter receptors and transporters that will help researchers studying neurological and psychiatric illnesses. The atlas data came from post-mortem tissue slices and will permit comparisons with PET or MRI scans.
Microdosing Could Reduce Animal Use and Speed Drug Development
Pharmaceutical companies looking for better ways to predict human reactions to new drugs are investigating a sophisticated new method called microdosing. Employed early on in the drug development process, the technique involves giving research participants miniscule dosages of an experimental drug—doses far too small to have any health effects—and then tracking the drug’s movement through the body. Researchers do this by radiolabeling a compound and then using high-tech software to see how the drug is distributed and metabolized in bodily fluids. The resulting data are far better than animal tests at enabling researchers to calculate the correct therapeutic dose and to understand drug kinetics before large-scale human clinical trials begin.
Recently, Seattle-based Radiant Research, Inc. completed microdosing tests re-evaluating the antiviral azidothymidine (AZT), a drug used by HIV patients. Researchers gave a group of healthy volunteers a dose approximately one-millionth the typical daily patient dose and were able to quantify drug concentrations in blood, urine, saliva, and white blood cells. Radiant’s chief executive officer, Michael Lester, says that microdosing will ensure that limited resources are focused on the best drug candidates, potentially saving time and money.
Soy May Promote Bone Health
A new study suggests that soy products may promote bone health. In a study of 24,000 postmenopausal women, followed for four years as part of the Shanghai Women’s Health Study, soy reduced the risk for fracture. Its protective effect was strongest among women in the early years of menopause, a time when rapid bone loss is common.
Zhang X, Shu XO, Li H, et al. Prospective cohort study of soy food consumption and risk of bone fracture among postmenopausal women. Arch Intern Med. 2005;165:1890-1895.
New Study Dispels Dairy/Weight-Loss Myth
One of the first long-term studies to analyze the relationship between dairy product consumption and weight refutes the controversial dairy industry claim that milk causes weight loss. Researchers randomly assigned 90 obese individuals to one of three groups, each instructed to consume various amounts of dairy products. One group consumed roughly 800 mg calcium per day; the other two consumed 1,400 mg calcium each, one with added fiber. All volunteers reduced their calorie intake by 500 calories per day. After one year, it was clear that milk had no effect. Researchers found no difference in weight loss or fat loss among the three groups.
Thompson WG, Rostad Holdman N, Janzow DJ, Slezak JM, Morris KL, Zemel MB. Effect of energy-reduced diets high in dairy products and fiber on weight loss in obese adults. Obes Res. 2005;13:1344-1353.
Want to Stay Slim? Fiber’s In, Fat’s Out
A high-fiber, low-fat diet protects women from becoming overweight, shows a new study by a team of scientists from the University of Hawaii, Tufts University, Bastyr University, and the U.S. Department of Agriculture. Using national survey data from more than 4,000 men and women aged 20 to 59, researchers investigated the relationship between dietary fiber and fat intake on body mass index (BMI) and the risk of becoming overweight. BMI is a measure of body weight adjusted for height. The researchers found that dietary fiber and a low-fat diet were both significant predictors for weight or BMI. In women, a low-fiber, high-fat diet was associated with a greater increase in risk for overweight compared with a high-fiber, low-fat diet. Fiber is found in beans, vegetables, fruits, and whole grains. Animal products never contain fiber.
Howarth NC, Huang TT, Roberts SB, McCrory MA. Dietary fiber and fat are associated with excess weight in young and middle-aged US adults. J Am Diet Assoc. 2005;105:1365-1372.