The Rural Voice, 2003-08, Page 53The leading edge
British scientist says environmental
conditions, not feed, key to BSE
A British researcher claims neuro-
degenerative diseases like bovine
spongiform encephalopathy and
chronic wasting disease are likely
linked to environmental conditions
rather than contaminated feed as most
scientists believe.
Professor David Brown, a biochem-
ist at the University of Bath, has a re-
search team that looks at prion type
diseases and possible connect -ions to
copper deficiencies and manganese
overload in animals' brains. (Prions,
contain protein, but no genes. Normal
prions exist in all brain cells.�Abnorm-
al prions, the suspected agents of dis-
eases like BSE, have a different shape.)
While at Cambridge University
Brown discovered prions require
copper to develop properly. If copper
is low and exposure to high levels of
manganese occurs, the prion may bind
to manganese and turn into a fatal
aberration that wastes away the brain.
Brown is one of a small cluster of
scientists who argue low copper
supplies and high manganese levels
are common factors among cases of
BSE, scrapie or chronic wasting
disease around the world. He claims
this scenario exists in Colorado and
Wyoming, where about one per cent
of deer have been affected by CWD.
Manganese poisoning could be
linked to the soil, water or even
industrial emissions, Brown feels. A
genetic factor may also cause
susceptibility to the disease.
"Certain breeds of sheep are more
susceptible to scrapie than others. It
all depends on the prion genes."
The theory that feeding contam-
inated protein manufactured from
BSE -infected animals causes BSE in
cattle and its human equivalent
Creutzfeldt-Jakob disease doesn't
make sense to Brown from a
biological perspective.
"The intestine breaks down
proteins and degrades them into
smaller parts so it seems almost
impossible that any amount of protein
could get into the body and have an
effect in the brain simply by eating
meat," he said.
Still, he agrees with the British
decision to keep all animals older than
30 months out of the food chain.
Brown is also working on a blood
test that does not require slaughter to
diagnose the disease. "One day we
might have a test and that will
revolutionize things and animals can
be screened," he said.
One supporter of Brown's copper
theory is retired Alberta Agriculture
plant pathologist and virologist Ieuen
Evans. He spent a career advocating
copper supplementation for cereal
crops. He contends the probable
birthplace of Canada's lone BSE case
in northwestern Saskatchewan is
highly deficient in copper.0
—Source: Western Producer
Poultry disease study seeks human answers
A University of Guelph researcher is studying the highly -infectious poultry
disease Marek's disease in an effort to understand similar viruses that affect
humans as well.
Professor Shayan Sharif, Department of Pathobiology, is investigating the
immunogenetics — the study of the genetics behind the immune system — of
Marek's disease (MD), an infectious viral disease responsible for an estimated $1
billion annual loss in the poultry industry.
MD is caused by a herpes virus that is shed from feather follicles and spreads
as fluff or dust, infecting the birds as they inhale. It can remain alive in an
environment for up to eight months, but does not infect humans. MD resistance
is highly inheritable, so that makes it an ideal disease to monitor which genes are
responsible for disease resistance.
"Understanding the genetic resistance to viral invasions could be the answer
to controlling viral infections in animals and humans," Sharif said.0
—Source: University of Guelph Research Magazine
50 THE RURAL VOICE
Sweetening farm profits
from fuel uses
A team of University of Guelph
scientists is examining novel ways
to replace non-renewable
petroleum with something that
will come back year after year —
agricultural products such as corn
sugar, soybean and canola oil and
possibly even plant wastes such as
corn cobs.
Their ultimate goal is to use
corn sugars or glycerol — the
major byproduct of biodiesel
production from food oils —
instead of the usual crude oil and
petroleum in chemicals and
plastics manufacturing. That
would lessen global dependence
on petroleum, find new uses for
otherwise low -value plant
products and give farmers a tidy
profit in the bargain.
Professor Marcel Schlaf and
graduate student Zhi Xie of the
Department of Chemistry and
Biochemistry have their eye on
glucose, an abundantly -produced
sugar and source of energy in
plants of all stripes and an
inexpensive compound obtainable
from corn starch and sugar beets,
as a crude oil replacement.
"Glucose is probably the most
abundant biological molecule on
the planet, so that's the compound
we need to work on," Schlaf says.
"The question is, can we take
glucose and use it to replace crude
oil as a building block?"
The problem is that glucose
and other carbohydrate molecules
are highly "functionalized" which
means they contain too many
reactive chemical groups to
undergo the same reactions that
petroleum-based chemicals do. So
before agricultural products can be
used as building blocks in
manufacturing, Schlaf and Xie
will have to develop new methods
to "defunctionalize" glucose and
other carbohydrates into usable
starting points for manufacturing
chemicals and plastics.0
— Source: University of Guelph
Research Magazine