Lab-animal alternatives are the new guinea pigs
by Melissa Suran
Aug 05, 2009
WASHINGTON – Scientific advancements in medical testing may reduce the need for animal subjects, eliminating the heated debate without another fight.
Although scientists are already carrying out many of the alternatives in major research, some believe there is still plenty of room for progress.
Dr. John Pippin, senior medical and research adviser of the Physicians Committee for Responsible Medicine, said animal experimentation should be completely banned for medical reasons as well as for the obvious ethical concerns.
According to Pippin, animal testing for human conditions can be misleading, and even dangerous, as the human anatomy is different from other animals – even our closest relatives – the great apes.
“There have been at least 85 successful vaccines to either cure or prevent HIV infection in animal models, mostly in monkeys,” said Pippin, a cardiologist. “Those vaccines… have been tested in approximately 200 human clinical trials. They have all failed.”
Additionally, Pippin said a recent trial conducted by Merck showed that people who received HIV vaccines that were originally tested on animals were more likely to contract HIV after taking the vaccine than people who took the placebo.
“That is fundamental proof that you’re on the wrong track,” said Pippin.
Theodora Capaldo, president of the New England Anti-Vivisection Society, also known as NEAVS, said many people have the dangerous misconception that experimenting on animals such as chimpanzees, who share many genetic similarities with humans, will help find cures for human-related ailments. In reality, Capaldo said he believes if animal experimentation was outlawed, humans would benefit.
“Yes, the genetic similarities between Homo sapiens and chimpanzees is even as little a difference as 2 to 3 percent, but it is enormous when it come to how disease occurs, progresses and what the outcome is,” Capaldo said.
Looking at HIV for example, Capaldo said chimpanzees are extremely poor models for testing for human cures. Chimpanzees cannot contract HIV, but only a virus similar to it. Additionally, because of our genetic differences, what does not effect a chimpanzee adversely may cause critical harm to a human.
And the evidence doesn’t stop there.
“There are more than two dozen cures for diabetes in animals; there is nothing successful in people,” Pippin said.
Once a professor of medicine at Harvard University, Pippin testified before the FDA and the Institute of Medicine in 2005 on the repercussions of animal experimentation, stating that such research led to life-threatening products, such as Vioxx, being released on the market.
Pippin admitted to once using animal models, mostly dogs, in his cardiovascular research. However, he stopped using them, he said, once he realized that caninesweren’t the most reliable models when trying to discover new ways to help people.
Fortunately, Pippin said there are many new, more humane and effective ways to conduct research. For example – using stem cells.
“You can already create human cell cultures and tissues that can be used for testing drugs in a way that’s more accurate than animal testing,” he said.
Additionally, Pippin said scientists can use microdosing, where humans are administered low, non-life threatening doses of a chemical that are still high enough to study how it is effective on a cellular level. The goal is to figure out what dose of a certain chemical should be added to new drugs.
In-vitro testing is also a popular alternate method, where human cells are placed in a test tube or Petri dish along with a chemical of choice to measure everything from toxicity to effectiveness.
These are only a few examples of the new and improved research methods, according to Pippin.
But not everyone agrees.
Amanda Banks, the president of the California Biomedical Research Association, said although scientists are making progress when it comes to alternatives, animal research is still critical to scientific advancements, especially when it comes to diseases.
Banks said many people think biomedical research is about “mascara on bunny rabbits.”
“We’re not talking about consumer products – we’re talking about human health, which is not frivolous,” she said in a telephone interview from Sacramento.
Researchers need to see how a compound is going to affect an entire live system, especially when it comes to toxicity testing, according to Banks.
Although she said in vitro is a good first step in drug testing, it should not be the only step.
“Once it works in the dish, will it work in the whole system?” she asked. “We don’t know if it won’t kill cells in the dish and not in the human. We need to know if it will knock out the kidney…drugs are a mild form of poison.”
But that doesn’t mean that the animals used should be subjected to cruelty.
“Bad animal care is bad science,” Banks said. “You won’t get good science results if your animal is distressed or in pain.”
There is inevitably, some pain that the animal will feel during the course of research and at the end of experiments. The animal subjects are usually euthanized.
Dr. Alan Leff, a pulmonary specialist at the University of Chicago Medical Center, agrees with Banks. For now, he said, animal testing still must play a big part in drug research.
“Research means discovery,” he said.
According to Leff, scientists need a live model to approximate what will happen in humans. The problem with computer models is that you can’t simulate life because of the multiple variables.
“People don’t do animal research because they like killing animals, they do it to discover what the possibilities will be,” Leff said.
Dr. David Jacobson-Kram, the associate director of pharmacology and toxicology in FDA’s Office of New Drugs, said that the FDA would not release drugs to the public that have not undergone some form of animal testing, at least in the preliminary stages.
“We need to do further research on mechanisms of toxicity to better understand how and why chemicals can be toxic to people,” he said, also mentioning that dogs are primarily used in such research due to the large, historical database of their results. “None of the drugs out on the market today would have been possible without animal testing.”
Although many may find animal testing to be inhumane, the FDA’s Jacobson-Kram assured that researchers must follow strict regulations to ensure that the animal is treated humanely, and if needed, euthanized humanely.
“I'm optimistic that science will be so advanced in the future that we will not need to test on animals,” he said. “For now, we do.”
According to Pippin, the FDA admitted that animal testing for drug safety can be inadequate when it responded to a report entitled “The Future of Drug Safety Promoting and Protecting the Health of the Public,” which was issued by the Institute of Medicine in September 2006.
Stuart Zola is director of the Yerkes National Primate Center at Emory University, a center that conducts biomedical and behavioral research on primates. Zola said that to abandon animal testing would be a disservice to those hoping to see a cure for diseases such as Alzheimer’s disease sooner rather than later.
“There are presumably some things you can do now using computer models or using cell cultures,” he said. “You can use cell cultures to ask questions about reactions to certain drugs…and impacts of drugs on neural activity…but those are just rather limited kinds of questions.”
Zola believes that scientists need live animals to study how their immune systems respond to new vaccines before clinical trials.
“While there are some things that you don’t need whole animal testing for, there are some things where we need whole animals,” Zola said.
Bioethicist Art Caplan said although he thinks significant progress has been made with animal-research alternatives, live models can’t be discredited across the board.
“We’ve gotten pretty far and I support that and I think for a lot of things you can use simulations and do better in some ways that try to get everyone to dissect their own cat or pig,” said Caplan, a professor at the University of Pennsylvania. “But for some things, you really do have to see the mess that is physiology.”
Caplan believes that anyone planning to become a surgeon, pathologist or anatomist needs hands-on physiological work.
“I don’t think you’d want a surgeon to operate on you yet, who only had simulation practice,” he said.
Even though Caplan said researchers cannot replace all animal experimentation with simulation at this point, “I think we will replace them all some day.”
That day is closer than we think, said Dr. Emad Aboud.
Aboud said he uses a special model when teaching surgery that works just as well as an animal model – if not better.
Aboud helped invent a model that pumps food-colored water into the vessels and arteries of a fresh human cadaver, which he said is much cheaper and more realistic than using an animal model.
“This is the perfect alternative to the use of live animals in surgical training,” said Aboud, a neurosurgeon fellow at the University of Arkansas for Medical Sciences in Little Rock.
Pippin, a fan of Aboud’s research, said he is also happy to see that the use of live animals has is disappearing from medical schools across the country.
“Of the 159 accredited U.S. medical schools, as of July 1, 2009, only eight continue to use any animal methods in training their students,” Pippin said. Canada is even farther ahead with only one medical school left using animals in student training, he said.
Pippin also noted that hundreds of millions of dollars are spent each year on animal-based research that may not even work – and this is nothing new.
“We have relied too heavily on animal testing, and we believed in it too strongly,” Marvin Pollard, the former president of the American Cancer Society, said in 1994. “Now, I think we are commencing to realize that what goes on in an animal may not necessarily be applicable to humans."
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