October
18,
1990
Vol.
9,
No.
7
tf
CANADIAN
SCIENCE
Executive
Editor:
Lydia
Dotto
Managing
Editor:
John
Holt
ISSN
0712-488
Published
by:
Canadian
Science
News
Service,
Room
H-02,
University
College,
University
of
Toronto,
Toronto,
Ont.
M5S
1
A1
(416)
595-7153
Canadian
Science
News
Service
acknowledges
a
grant
from
the
Science
Culture
Canada
Program
Drug
can
reduce
aluminum
in
Alzheimer's
My
Sully
Johnston
University
of
,
Toronto
medical
researchers
appear
to
have
taken
a
step
forward
in
the
fight
against
Alzheimer's
disease,
which
afflicts
at
least
300,000
Canadians.
The
team
of
scientists,
at
the
Centre
for
Research
in
Neurodegenerative
Diseases,
has
found
that
a
drug
called
desferoxamine
can
decrease
levels
of
aluminum
in
the
brain.
Aluminum
is
thought
to
play
a
role
in
Alzheimer's,
which
causes
mental
deterioration.
Dr.
Ted
Kruck.
one
of
the
researchers,
cautions
that
the
drug
is
not
a
potential
cure,
But
it
does
offer
a
-
hope
of
stabilizing
or
slowing
the
advance
of
the
disease,
he
adds.
"We
are
optimistic
that
the
drug
will
help
patients
to
maintain
quality
of
lile,".lie
says.
Alzheimer's,
an
insidious
disease,
causes
the
steady
death
of
brain
cells.
At
the
same
tune,
an
excessive
amount
of
a
certain
protein
accumulates
in
the
brain,
forming
a
mass
of
tangled,
twisted
filaments.
Gradually,
Alzheimer's
patients,
who
are
generally
elder
ly,
become
increasingly
forgetful
and
confused,
until
they
can
no
longer
look
after
themselves.
Kruck
says
that
post-mortem
tests
on
the
brains
of
about
50
Alzheimer's
victims
showed
that
all
contained
elevated
levels
of
aluminum.
Those
tested
had
about
four
micrograms
of
aluminum
per
gram
of
dried
brain
Alberta
heart
study
surveys
Hutterites
II)
John
KliiiU'i'
A
University
nl
Victoria
epidemiologist
who
is
surveying
ihe
cardiovascular
Imicss
and
incidence
of
heart
disease
among
Alberta
llutleriies
ha
found
lliey
hae
a
highcr-lhau-average
incidence
ol
risk
factors
for
heart
disease
but,
curiously,
appear
to
suiter
hc.u
I
disease
no
more
than
comparable
groups
of
other
Canadians.
The
study
may
help
sort
out
the
relative
iiupoilaikc
ol
genetic
versus
eiiviniiunenl.il
nvk
lailors
m
causing
heart
attacks
and
siiokes.
In
addition.
Die
inhumation
gained
will
provide
the
basis
for
lulure
health
promotion
campaigns
in
lluttente
communities,
say
Dr.
Howard
Drum,
an
associate
professor
in
the
I
acuity
of
human
and
social
development.
Alberta's
Hutterites
arc
descended
from
300
Eastern
Europeans
who
emigrated
to
North
America
in
the
late
1800s.
Fleeing
from
religious
persecution,
the
founding
population
soon
spjit
into
three
distinct
groups
or
'sects',
and
set
up
colonies
tliroughoul
die
prairie
provinces
and
northwestern
UniledSlalcs.
"They're
a
very
unique
people
in
being
both
socially
and
genetically
isolated
from
the
rest
of
society,"
says
Brunt.
Hutterites
rarely
marry
outsiders,
he
explains.
In
fact,
"there's
very
little
genetic
exchange
between
sects."
Despite
this,
the
different
sects
have
adopted
similar
lifestyles
-
a
factor
that
makes
it
possible
"to
tease
out
the
environmental
and
genetic
risk
factors
for
heart
disi;asc
at
die
same
lime."
Brunt
says
the
problem
with
examining
more
mixed
groups
is
that
they
display
a
wide
range
of
risk
factors.
"Some
people
smoke,
some
doii'l.
Some
people
drink,
some
don't.
Arid
diets
lend
to
range
all
over
the
place."
Preliminary
results
indicate
the
prevalence
of
hypertension
(high
blood
pressure)
-
a
major
risk
factor
-
is
tissue,
compared
to
about
two
micrograms
in
ieople
who
died
of
oilier
causes,
including
oilier
dementia
patients.
"We
believe
aluminum
messes
up
the
normal
processes
of
the
brain,"
says
Kruck.
The
element
appears
to
adhere
to
certain
brain
cells,
causing
an
effect
a
bit
like
running
through
a
library
with
a
slick
of
glue,
he
adds.
If
the
pages
of
books
are
stuck
together,
the
book
no
longer
makes
sense.
hi
a
preliminary
lest,
the
researchers
used
desferoxamine
on
Alzheimer's
patients
whose
brains
were
examined
for
aluminum
afler
tliey
finally
died.
The
patients
who
had
taken
the
drug
had
brain
levels
of
aluminum
60
cr
cent
lower
than
those
who
had
not
taken
the
dnig.
Now
Kruck
has
recently
completed
a
two-year
study
Willi
50
Alzheimer's
patients,
half
of
whom
were
treated
with
desferoxamine.
At
regular
intervals
Uie
patients
were
given
simple
tests,
such
as
counting
change
and
putting
on
a
sweater.
The
tests
were
recoided
on
videotape
and
later
compared
to
see
if
ihe
patients
showed
signs
of
progressing
menial
deterioialiou.
"We
are
looking
for
an
indication
thai
Ihedrug
will
prevent
further
deterioration,"
says
Kruck.
"We
can't
hope
for
a
cure
localise
once
Ihe
brain
cells
are
dead
you
can't
bung
them
back."
Results
of
the
study
are
Iving
much
greater
among
llutleriies
than
in
society
ai
laige.
"Approximately
60
per
cent
ol
ihe
adult
males
and
30
er
cent
of
the
females
we
looked
at
had
high
blood
pressure,"
he
says.
"This
is
about
double
what
a
recent
Nova
Scotia
health
survey
found."
llutleriies
are
also
more
prone
to
high
cholesterol
levels
than
the
general
Hpulation.
And
lliey
lend
to
score
high
on
die
'body
mas
indekfs
a
measurement
of
weight
distribution.
"In
Canada,
a
Ixidy
mass
index
alxive
27
is
considered
to
put
someone
at
a
greatly
increased
risk
for
heart
disease,"
says
Drum.
Among
the
Hutterites
studied,
"52
ver
cent
of
the
males
and
53
per
cent
of
the
females
were
in
this
range."
Yet
their
medical
records
do
not
convey
ihis
reality.
Brunt
found
the
actual
incidence
of
heart
disease
among
his
subjects
was
no
higher
than
among
any
comparably-sized
group
of
ordinary
Canadians.
'The
fact
dial
less
titan
5
per
cent
of
Hutterites
smoke
may
in
part
explain
this
finding,"
he
says.
"Smoking
accounts
for
30
per
cent
of
die
total
risk
in
heart
disease."
On
the
other
hand,
it's
twssible
Hutlerile
medical
records
don't
tell
the
whole
story.
Brunt
suggests
dial
their
.high
incidence
of
hy)crtcnsion
may
put
litem
at
greater
risk
of
sudden
death
and,
being
rural
dwellers,
they
have
less
access
to
advanced
medical
care
in
emergencies.
To
lest
litis
hypothesis.
Brunt
intends
to
"wade
dirough
30
years
worth
of
death
certificates."
His
research
agenda
also
calls
for
a
comparison
of
two
Alberta
sects.
Subtle
differences
in
the
cardiovascular
fitness
of
die
two
groups
may
point
to
genetic
factors
at
work,
he
says.
Brunt's
research
is
supxrtcd
by
a
grant
from
Health
and
Welfare
Canada.
(Canadian
Science
News)
evaluated
and
will
be
published
soon.
Ahh
.igh
the
human
body
needs
some
trace
elements
-
for
example,
iron
in
the
blood
-
aluminum
has
no
biological
activity
other
than
being
loxic,
Kruck
says.
But
because
humans
arc
constantly
exposed
to
aluminum
-
one-third
of
the
Earth's
crust
contains
the
clement
in
one
form
or
another,
so
it's
in
many
foods
the
body
has
built
up
an
"excellent
resistance,"
he
says.
'There's
a
billion
to
one
chance
of
any
aluminum
you
swallow
gelling
from
your
stomach
to
your
Wain.
Normally,
it's
washed
out
when
you
pee."
Ultrasonic
welding
technique
can
join
almost
any
materials
Mtfev
ma
"
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,
t
M
l
i
IV
jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjift
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iHK
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t?lyBHlSfe44L!P
Researcher
Nao
Talelshl
with
ultrasonic
welding
device
developed
by
a
team
ul
University
of
Toronto,
(Photo
courtesy
Nuo
TateUhi,
U
of
Toronto)
By
John
Kberlte
University
of
Toronto
researchers
have
developed
a
process
for
welding
just
about
any
two
rigid
materials
by
Using
ultrasonic
energy.
Professor
Kay
Woodhams,
a
chemical
engineer,
and
his
colleague
Tom
North,
a
professor
of
metallurgy,
have
found
that,
by
aiming
high
frequency
sounds
at
a
sound-absorbing
adhesive
sandwiched
between
the
materials
to
be
joined,
they
can
weld
plastics,
wood,
ceramics,
glass,
steel
and
other
metals
to
each
other.
Previously,
ultrasound
has
only
been
used
to
join
plasties.
The
process
could
be
used
for
many
things
-
for
example,
sticking
the
parts
of
plastic
cigarette
lighters
together,
welding
plastic
body
panels
on
cars,
even
slicking
together
plaslic-composilc
panels
on
aircraft
or
welding
structural
steel
beams.
Woodhams
says
the
U
of
T
process
takes
less
than
half
a
second
and
results
in
"perfect
joining.
In
other
words,
the
bond
becomes
stronger
than
die
materials
themselves."
The
technique
is
less
expensive
than
some
commercial
processes,
such
as
Still,
over
a
lifetime,
some
aluminum
does
accumulate
in
everyone's
brain.
The
body
seems
able
to
cope
with
it
up
to
alxwl
two
micrograms
per
gram
of
brain
tissue.
Why
Alzheimer's
patients
accumulate
more
aluminum,
pushing
them
beyond
the
tolerable
limit,
is
not
fully
understood,
says
Kruck.
Scientists
suspect
it
may
be
a
genetic
trail,
causing
'leaks'
in
Ihe
body's
resistance.
Some
processed
foods
may
also
contain
forms
of
aluminum
that
arc
able
to
"by-pass,
the
barriers,"
says
Kruck.
electromagnetic
welding,
he
adds.
"It's
very
energy-efficient.
There's
very
little
heal
loss
al
die
weld,
so
energy
cosls
are
low."
The
new
welding
process
evolved
out
of
his
discovery,
several
years
ago,
dial
plastics
containing
Tine
rubber
particles
make
effective
sound
barriers.
"We
found
you
don't
need
heavy
Eggshells
reused
A
Winnipeg
egg-processing
firm
has
hatched
a
profitable
plan
to
recycle
millions
of
waste
egg
shells
it
grinds
diem
into
feed
for
chickens.
Export
Packers
Company
Ltd.
uses
1.3
million
eggs
a
day
in
the
extraction
of
enzymes
and
manufacture
of
dehydrated
egg
powders.
That
leaves
Uiem
with
a
soggy
heap
of
waste
shells
dial
used
to
be
sent
to
the
local
garbage
dump.
Now
the
company
has
devised
a
process
to
turn
the
waste
shells
into
a
jHiullry
feed
supplement,
called
Egg
Shell
Meal,
a
rich
source
of
calcium
and
protein
for
chickens.
The
project
has
two
major
victims
Dried
pasta,
chocolate-flavoured
drinks
and
bottled
pickles
are
among
foods
that
may
have
added
aluminum
compounds
to
enhance
flavour
and
colour.
Most
brands
of
antacid
tablets
also
contain
aluminum
compounds,
says
Kruck.
At
present,
there
are
no
government
restrictions
on
the
use
of
aluminum
additives
in
food.
But
many
food
manufacturers
arc
dropping
their
use
as
scientific
evidence
builds
about
lite
dangers
of
aluminum
to
the
human
body,
Kruck
says.
(Canadian
Science
News)
concrete
walls
in
buildings
to
insulate
sound,"
he
says.
"You
can
actually
use
a
thin
film
of
rubberized
plastic
which
absorbs
sound
energy,
converting
it
into
heal."
Later,
while
exploring
iccltniqucs
for
welding
rigid
plastics,
Woodhams
and
North
noted
how
the
temperature
of
some
sound-absorbing
materials
will
reach
2000
degrees
C
in
one
second
-die
result
of
exposure
to
frequencies
beyond
the
upiwr
limit
of
human
hearing.
By
carefully
controlling
such
ultrasonic
bursts,
it's
possible
to
melt
a
thin
layer
ol
rubberized
xlypropylene,
let
it
cool,
and
effect
a
permanent
weld
within
half
a
second,
says
Woodhams.
Polypropylene
is
an
ideal
adhesive
because
"it
actually
becomes
entangled
will)
ihe
surface
molecules
of
whatever
it's
between."
Once
formed,
such
a
bond
resists
environmental
extremes
of
lenierature,
moisture
and
ultraviolet
radiation,
he
adds.
However,
if
the
weld
is
rc-cxposcd
to
uluasound,
it
separates
easily
-
an
advantage
over
oilier
processes
used
in
manufacturing.
"If
you
damage
a
car
panel,
you
jusl
have
to
re-expose
the
affected
area
and
die
panel
will
come
off,"
he
explains.
"Then
you
can
reweld
an
undamaged
panel
in
its
place."
However,
if
necessary
ihe
weld
can
le
made
permanent.
Adding
certain
chemicals
to
the
adhesive
causes
it
to
'set'
in
such
a
way
dial
neither
ultrasound
nor
extreme
heat
-
for
example,
a
blowtorch
-
will
undo
il.
He
says
the
only
limitation
of
ultrasonic
welding
is
its
performance
when
joining
materials
that
absorb
sound.
'The
process
works
best
on
materials
that
arc
transparent
to
ultrasonic
sound.
Thus,
it's
easier
to
weld
two
thick
steel
girders
titan
two
thick
pieces
of
polyethylene.''
Funding
for
this
research
came
from
the
Natural
Sciences
and
Engineering
Research
Council
and
the
Ontario
Ccntc
for
Materials
Research.
(Canadian
Science
News)
as
chicken
feed
environmental
benefits:
it
eliminates
die
pile
of
wet
egg
shells
thai
posed
a
health
hazard
to
the
food
processing
plant
by
attracting
insects
and
bacteria,
and
il
reduces
the
amount
of
waste
headed
for
landfill
sites
by
6.800
kilograms
daily.
Egg
Shell
Meal
has
turned
out
to
be
a
real
money
maker.
Annual
sales
of
the
poultry
feed
exceed
$110,000
and
lite
company
saves
more
than
$40,000
a
year
in
disposal
charges.
WiUt
an
expanded
egg-processing
plant
and
new
equipment,
all
the
former
waste
shells
are
now
processed
into
the
feed
supplement.
(Canadian
Science
News)