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;20:316-23.
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.
Visit http://cba.cpmc.columbia.edu.
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.
Bone Health:
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;165:1890-5.
Weight Loss
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;13:1344-53.
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;105:1365-72.
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