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By Kristie Sullivan, M.P.H., and John J. Pippin, M.D.
ALTERNATIVES TO ANIMAL RESEARCH
Lab-Grown Bladders Help Sick Children
In a pioneering achievement in tissue engineering, researchers at Wake Forest University announced this spring that patients who received bladders grown from the patients’ own cells have been successfully using the implanted organs for about four years. The patients were all children who suffered from spina bifida, a disease that, among other complications, can result in shrunken, dysfunctional bladders.
The cells were taken by biopsy from the children’s nonfunctional bladders, and then allowed to grow in the laboratory into the shape of a bladder. After two months, the bladders were surgically grafted onto the patients’ own bladders. The researchers’ next goal is to grow an entire bladder, complete with a sphincter to regulate urine flow, and then, perhaps, develop more complex organs.
Though growing more complicated organs such as hearts or livers presents other obstacles, the victory is encouraging news for scientists and patients. It is also hopeful for animals, because it is a good replacement for experiments attempting to use animal organs in humans.
Source: New Scientist, Apr. 8, 2006, p. 10.
Pharmagene Changes Name, Keeps Ethical Testing
A company that made a name for itself testing new pharmaceuticals exclusively in human tissues, Pharmagene, has changed its name to Asterand. However, the company has not changed its commitment to effective and ethical safety testing of drugs. Many new treatments for cancer and other diseases are antibody-based. These treatments are designed to bind to a specific cell or receptor to enact their effect. However, if the antibody binds to other, nontarget tissues, patients can have a violent allergic reaction, similar to the recent disastrous trial in London with the drug known as TGN1412.
Asterand scientists have developed an antibody assay that, when applied to a range of tissues from the human body, will predict whether such unanticipated immune reactions, which cannot be predicted through animal tests, might occur. This means safer clinical trials and fewer animal tests.
Source: Asterand plc
Vioxx Users More Susceptible to Side Effects in First Weeks
As PCRM continues to pursue its lawsuit against the pharmaceutical giant Merck for the company’s reliance on animal tests for the pain-killer Vioxx, disturbing new information has surfaced about the drug, which was withdrawn from the market in 2004 because it doubled the risk of heart attacks and stroke. A new study by researchers at McGill University Medical Centre in Montreal recently found that some patients using Vioxx are most susceptible to the drug’s cardiotoxic effects immediately after starting to take it. One-quarter of the participants in the epidemiological study experienced a heart attack within 14 days of starting a Vioxx prescription.
This data further highlights how poorly predictive animal “safety” tests can be; Vioxx was certified safe in FDA-required animal tests, and was even shown to be cardio-protective in mice. It has the opposite effect in people.
Source: Levesque, et al. 2006; Canadian Medical Association Journal. 174(11).
By Dulcie Ward, R.D., and Susan Levin, M.S., R.D.
Arsenic Found in Chicken
Chicken often contains dangerous amounts of arsenic, according to a new report. Researchers from the Institute of Agriculture and Trade Policy tested for arsenic in 151 samples of raw chicken from supermarkets and 90 samples of cooked chicken from 10 different well-known fast-food restaurants. Arsenic is a known carcinogen and is linked to neurological, cardiovascular, and immune problems. It is commonly added to chicken feed to improve feed efficiency, improve pigmentation, promote faster weight gain, or prevent intestinal infection caused by parasites.
The study found that 55 percent of uncooked chicken products contained detectable arsenic, and 100 percent of the fast-food brands had detectable levels of the toxic element. The arsenic content varied, although many samples were well above the Environmental Protection Agency’s 10 parts per billion standard allowable in public drinking water.
Institute for Agriculture and Trade Policy. Playing Chicken: Avoiding Arsenic in Your Meat. Minneapolis, Minnesota: Institute for Agriculture and Trade Policy 2006.
Vegan Diet for Diabetes
A new study presented at the American Diabetes Association’s (ADA) annual scientific conference in Washington, D.C., suggests that people with type 2 diabetes improve significantly with a low-fat, plant-based diet. In a controlled trial, conducted by investigators from PCRM, the George Washington University, and the University of Toronto, 99 participants were randomly assigned to follow either a low-fat, vegan diet or a more standard ADA diet. ADA guidelines allow for all food types but in limited quantities. Many participants were able to reduce their medication in the course of the study. Among participants whose medications stayed constant, the vegan diet improved patients’ hemoglobin A1c, the main indicator of long-term blood glucose control, by an average reduction of 1.2 points, a drop significantly greater than the effect of most diabetes drugs and three times greater than experienced by those following the ADA diet.
Other benefits for the vegan group were greater reductions in low density lipoprotein (LDL, or “bad”) cholesterol levels and greater weight loss. Among medication-stable participants, body weight fell an average of 14.3 pounds in the vegan group and 6.8 pounds in the ADA group.
Barnard ND, Cohen J, Jenkins D, Turner-McGrievy G. Effect of a plant-based diet on glycemic control and cardiovascular risk factors in individuals with type 2 diabetes: a randomized clinical trial. Presented at: American Diabetes Association 66th Scientific Sessions; June 9, 2006; Washington, D.C.
Obesity Fuels Diabetes
A new study confirms the role of obesity in diabetes risk. The Centers for Disease Control and Prevention compiled national health survey data from 1997 to 2003 to examine trends in the incidence of diagnosed diabetes among U.S. adults. Of those with diabetes in 2003, 89 percent were overweight or obese (30 percent and 59 percent, respectively). The total increase in diagnosed diabetes was 41 percent.
While this study did not distinguish between type 1 (formerly called “childhood-onset”) diabetes and type 2 (“adult-onset”) diabetes, type 2 accounts for 90 percent to 95 percent of all diabetes cases. Because type 2 diabetes often relates to body weight, a change in diet and lifestyle can reduce the risk of the disease and aid in its treatment.
Geiss LS, Pan L, Cadwell B, Gregg EW, Benjamin SM, Engelgau MM. Changes in incidence of diabetes in U.S. adults, 1997-2003. Am J Prev Med. 2006;30:371-377.