[ RadSafe ] RE: Sick cats in Australia from irradiated food... Possible cause

[Cary Renquist]

Saw this article and remembered a series of posts earlier in the year
about sick cats in 
Australia that was attributed to irradiated cat food.

Well, the exact cause is unknown, but...  
It appears that a diet of irradiated food causes the myelin layer of
nerves in cats to degrade.

Cary

http://www.sciencedaily.com/releases/2009/03/090330200722.htm

Nine Lives: Cats' Central Nervous System Can Repair Itself And Restore
Function

ScienceDaily (Mar. 31, 2009) - Scientists studying a mysterious
neurological affliction in cats have discovered a surprising ability of
the central nervous system to repair itself and restore function.

In a study published March 30, 2009 in the Proceedings of the National
Academy of Sciences, a team of researchers from the University of
Wisconsin-Madison reports that the restoration in cats of myelin - a
fatty insulator of nerve fibers that degrades in a host of human central
nervous system disorders, the most common of which is multiple sclerosis
- can lead to functional recovery.

"The fundamental point of the study is that it proves unequivocally that
extensive remyelination can lead to recovery from a severe neurological
disorder," says Ian Duncan, the UW-Madison neuroscientist who led the
research. "It indicates the profound ability of the central nervous
system to repair itself."

The finding is important because it underscores the validity of
strategies to reestablish myelin as a therapy for treating a range of
severe neurological diseases associated with the loss or damage of
myelin, but where the nerves themselves remain intact.

Myelin is a fatty substance that forms a sheath for nerve fibers, known
as axons, and facilitates the conduction of nerve signals. Its loss
through disease causes impairment of sensation, movement, cognition and
other functions, depending on which nerves are affected.

The new study arose from a mysterious affliction of pregnant cats. A
company testing the effects on growth and development in cats using
diets that had been irradiated reported that some cats developed severe
neurological dysfunction, including movement disorders, vision loss and
paralysis. Taken off the diet, the cats recovered slowly, but eventually
all lost functions were restored.

"After being on the diet for three to four months, the pregnant cats
started to develop progressive neurological disease," says Duncan, a
professor of medical sciences at the UW-Madison School of Veterinary
Medicine and an authority on demyelinating diseases. "Cats put back on a
normal diet recovered. It's a very puzzling demyelinating disease."

The afflicted cats were shown to have severe and widely distributed
demyelination of the central nervous system, according to Duncan. And
while the neurological symptoms exhibited by the cats are similar to
those experienced by humans with demyelination disorders, the malady
does not seem to be like any of the known myelin-related diseases of
humans.

In cats removed from the diet, recovery was slow, but all of the
previously demyelinated axons became remyelinated. The restored myelin
sheaths, however, were not as thick as healthy myelin, Duncan notes.

"It's not normal, but from a physiological standpoint, the thin myelin
membrane restores function," he says. "It's doing what it is supposed to
do."

Knowing that the central nervous system retains the ability to forge new
myelin sheaths anywhere the nerves themselves are preserved provides
strong support for the idea that if myelin can be restored in diseases
such as multiple sclerosis, it may be possible for patients to regain
lost or impaired functions: "The key thing is that it absolutely
confirms the notion that remyelinating strategies are clinically
important," Duncan says.

The exact cause of the neurological affliction in the cats on the
experimental diet is unknown, says Duncan, who was not involved in the
original study of diet.

"We think it is extremely unlikely that [irradiated food] could become a
human health problem," Duncan explains. "We think it is species
specific. It's important to note these cats were fed a diet of
irradiated food for a period of time."

In addition to Duncan, authors of the new PNAS study include Alexandra
Brower of the Wisconsin Veterinary Diagnostic Laboratory; Yoichi Kondo
and Ronald Schultz of the UW-Madison School of Veterinary Medicine; and
Joseph Curlee, Jr. of Harlan Laboratories in Madison.
Adapted from materials provided by University of Wisconsin-Madison, via
EurekAlert!, a service of AAAS.