By now you may have read the Lenzen Aging Services, Inc. Mission/Vision statements and already gotten a taste of what we do here, which includes various active and proactive services. These blogs exist for a very different intent, which is to educate and tantalize by focusing on the “big picture” which will hopefully provide additional value for the 60+ crowd. Our motto is “Adding Light to Old Notions” which means we won’t necessarily replace the old with the new, as sometimes the old remains a better choice in many ways. When it doesn’t, additional knowledge may be obtained via a well performed study or by posing the right questions, exploring the different ramifications of that question, formulating reasonable conjectures and then using decades of learning (A priori/A posteriori knowledge) to come to a conclusion….. or not. Many times the deduction is not nearly as satisfying as the thought process itself.
One very important point to be made is that we choose not to use animal model studies for informational purposes. Many of you reading this will not agree since a Gallop poll shows that 2/3s of Americans believe medical testing on animals is morally acceptable and that their lives are worth the sacrifice. Let’s think this through since, for starters, we know that the age factor is important in that a 65 year old will respond very differently to certain drugs than a 30 yr. old. There are differences between the sexes, also. A 2015 study showed that female liver cells are more susceptible to the side effects of drugs at the cellular level than are males. There is plenty of evidence that animal studies may not translate to humans, since we are obviously different in many ways, biologically speaking. One of many examples is from a University of Utah study which determined that the amount of sugar toxic to mice cannot be equated to the same outcome in the human body, since many of these studies create an unlikely human scenario, according to Kenneth Litwak, D.V.M., Ph.D. PCRM also reviewed a study in the Proceedings of the National Academy of Sciences, which found data showing a response to inflammation in humans may not be reproduced in mice. More than 150 drugs tested on mice failed in patients with sepsis, for example. The author concluded that “New approaches need to be explored to improve the ways that human diseases are studied.” The New England Anti-Vivisection Society and the National Anti-Vivisection Society feel strongly that alternative scientific methods are not only humane and less wasteful, but give more “human relevant” results. Some alternatives could include Direct Peptide Reactivity Assay, human tissue sampling in a test tube, stem cell microchip technology, SynDavers, and Genome-wide profiling to name a few.
Last year, NEAVS stated that the reported 90-93% genetic similarity between us and monkeys does not result in “sufficient physiological similarity….to constitute good models for research, and that monkey data do not translate well… in clinical practice for humans.” There appears to be particularly poor extrapolations in research on Alzheimer’s disease, Parkinson’s disease and stroke since the “major molecular differences underlying these inter-species phenotypic disparities have been revealed by comparative genomics and molecular biology….” There are key differences in gene expression and protein function and other important widespread factors, which “show that the superficial similarity between human and monkey genetic sequences is of little benefit for biomedical research……and highly unreliable….particularly given the breadth and potential of alternative methods of enquiry that are currently available to scientists.”
The FDA animal programs are accredited by the Association for Assessment and Accreditation of Lab Animal Care Int’l, which promotes the humane treatment of animals in science, which is a good concept. But let’s couple the above information with the National Institutes of Health who stated in their own meta-analyses of all available animal data, that in certain drug studies there was found a “major discordance between the results of the animal experiments and human trials.” They discovered consistent methodological flaws throughout yet many did offer consistent results. However, in reviewing 76 highly cited animal studies, only about one third translated at the level of human randomized trials. They reasoned that methodological biases, lack of uniform requirements, not randomizing or blinding correctly, and inadequate size were the main culprits. Their second explanation, more important to our discussion, is that animal models may not adequately mimic human pathophysiology. At lyrica.com you’ll find an interesting statement referring to the drug which says, “a specific type of blood vessel tumor was seen in mice, but not in rats. The meaning of these findings in humans is not known,” which shows that rats and mice can respond differently. The point is that the next time you search for information or hear about breaking news in the media of a new study associating this risk or that benefit, keep this in mind……..a benefit or risk to you or a rat?
- Jane Alise
References
~http://www.gallup.com/poll/11767/Americans-Unruffled-Animal-Testing.aspx.
~http://www.pcrm.org.
~http://www.neavs.org & navs.org
~Bailey, J. (2014) Alternatives to Laboratory Animals, 42 (5).
~Hackam, D. G., Translating animal research into clinical benefit. British Medical Journal, 334 (7586) 163-164.
~http://www.lyrica.com