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Post-Polio Health (ISSN 1066-5331)

Vol. 18, No. 4, Fall 2002
Read selected articles from this issue ...

Mouse Model Developed for Post-Polio Research

Editor's Comments
Joan L. Headley, Executive Director, GINI

Pursuing Therapeutic Resources to Improve Your Health
Linda L. Bieniek, CEAP, La Grange, Illinois, and Karen Kennedy, MSW, RSW, Toronto, Canada

Treatment Approach Options Chart

The GINI Research Fund Awards Grant of $25,000

The GINI Research Fund First Award Recipient Releases Final Report


Editor's Comments ...

Joan L. Headley, Executive Director
Post-Polio Health International (editor@post-polio.org

It happened again. I received another phone call from a reporter who wanted to know "what polio survivors think." He wanted to know what polio survivors thoughs a stamp of approval for the work we are doing. Although you are not listed, those you chose to honor are. We thank you for your financial support and for letting us know "what you think."


Mouse Model Developed for Post-Polio Research

In the winter of 2001, Burk Jubelt, MD, and Jeremy Shefner, MD, of Upstate Medical University, Syracuse, New York, and Rob Morris, who had polio as an infant, sat down to discuss the existing therapeutic alternatives for the array of symptoms seen in post-polio syndrome.

The criteria for the diagnosis of post-polio syndrome (PPS) include:

It was clear that the current therapies are supportive and decrease weakness, pain and fatigue, etc., rather than halt or reverse the underlying pathology, or the cause.

Eventually, the conversation turned to the relatively recent developments in regenerative and neuro-protectant medical research. The obvious question was whether or not some of that work might be applicable to post-polio syndrome. The conclusion was that, in theory, certain combinations of pharmaceuticals, nerve growth factors and cellular therapies might result in useful therapies. However, in order to test any of the new therapies a reliable animal model of post-polio syndrome would have to be created, as trying such therapies first on human subjects would be unethical.

Morris agreed to provide funding for a research proposal crafted by Jubelt, Rapka and Shefner to develop a post-polio mouse model. A group of mice were infected with the poliovirus and then the researchers compared their neurological development with that of a group of mice that were not similarly infected with the poliovirus (a control).

The plan was to follow the mice for over a year and measure both their level of nerve damage and muscle function. Then, other studies would be performed on the mice to examine the three principal theories of the pathology of post-polio syndrome.

Degenerative theory, the most widely held theory, postulates that the new sprouts which grew to substitute for the sprouts killed by the original infection are dying back due to exhaustion from increased metabolic demand over years of use.

Viral theory hypothesizes that the old poliovirus has either lain dormant in the central nervous system or mutated into a form that is slowly destroying nerve tissue. No conclusive evidence for this theory has ever been established.

Immune mediated theory implies that inflammation or an auto-immune mechanism has led to the symptoms. Empirical evidence for this theory has been contradictory.2

An abstract published by Drs. Jubelt, Rapka, and Shefner in Neurology (Apr. 1, 2002, Suppl. 3) indicates that the mice exhibited electromyographic patterns similar to that seen in individuals with post-polio syndrome. (See figure 1, below) The mice had a decreased number of motor units (MUNE in Figure 1), and the remaining units were enlarged (SMUP Amplitude in Figure 1). Additionally, degenerative neurologic changes were seen in both symptomatic and asymptomatic mice.

Fig. 1. Mouse Model

During the summer of 2002, the mice were sacrificed and analyzed for inflammatory and viral evidence. The results of this work and the final EMG studies are expected to be completed and submitted for publication this fall.

Additional funding allowed the researchers to inoculate more mice to create a population of mature mice, analogous to a 40-year or older human experiencing post-polio syndrome. These mice will ready for further testing after additional funding for test materials is raised.

Burk JubeltDr. Jubelt commented, "We are very excited about the potential for the mouse model. We should be able to sort out the cause of the late weakness seen in post-polio syndrome. Once the cause is sorted out, many options are available for possible therapeutic benefit.

The model will allow us to test these different therapies."

Burk Jubelt, MD, Professor and Chairman of the Department of Neurology of SUNY Upstate Medical Center, Syracuse, New York, is also Director of the Post-Polio Clinic and the Post-Polio Research Program. Dr. Jubelt has researched post-polio syndrome for 18 years.

References

1. Jubelt, B., & Drucker J. (1999). Poliomyelitis and the post-polio syndrome. In: Younger D.S., Ed., Motor Disorders, 381-395. Philadelphia, PA: Lippincott Williams & Wilkins.

2. Jubelt, B., & Cashman, N.R. (1987). "Neurological manifestations of the post polio syndrome" Crit. Rev. Neurobiol. 3, 199-220. 

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