SCHOOL EDITION 3 MAY 2023 - Flipbook - Page 23
Wednesday, March 7, 2018
www.irishnews.com
37
Is this the
wonder drug
that could
finally halt
dementia?
By Lucy Elkins
D
EMENTIA is now the
disease we fear more
than any other, even
cancer.
As Dr James Pickett,
head of research at
the Alzheimer’s Society, explains:
‘It is currently the only one of the
top ten killers that we can’t cure,
prevent or even slow down.’
But a new trial is now under
way of a drug, miridesap, which, if
successful, could radically change
the outlook for those affected with
Alzheimer’s, the most common
form of dementia.
‘Potentially the biggest thing
since sliced bread,’ is how the man
who developed the drug, Professor
Sir Mark Pepys, an immunologist
and director of the Wolfson Drug
Discovery Unit at University
College London, describes it.
Miridesap targets a protein
called serum amyloid P
component (SAP) which is newly
suspected to play a key role in
Alzheimer’s. Most of the drugs
previously tested have targeted
amyloid plaques — microscopic
tangles of abnormal protein which
are found wrapped around brain
cells in great quantities in those
with Alzheimer’s.
The belief was that these tangles
play a key part in the death of
brain cells and the loss of memory
and cognition that characterise the
disease.
SAP is being targeted now as
it has a double negative effect —
destroying brain cells as well as
protecting (harmful) amyloid.
Professor Pepys believes that
SAP is a vital mechanism in
Alzheimer’s and might explain
why previous drugs that only
targeted amyloid have not worked.
Miridesap, it is hoped, will clear
the amyloid, too.
‘Amyloid should be cleared
from the body by macrophages
that eat up and destroy general
debris from around the cells,’ says
Professor Pepys. ‘But SAP puts a
protective coating on amyloid so it
can’t be cleared.’
Miridesap resembles the outer
coating of amyloid so SAP locks
Caption style to go ini n this space Caption style to go ini n this space Caption style to go ini n this space
onto it instead — and, deprived
of its protective cover, amyloid is
then ingested in the liver. A small
trial in 2005 found that miridesap
cleared all SAP from the blood
and also from the fluid around the
brain in those with dementia.
The hope is that in the absence
of SAP, macrophages will then get
to work on tackling the 100mg or
so of amyloid that accumulates
in the brains of people with
Alzheimer’s.
The plan is to recruit 100
volunteers with mild Alzheimer’s
who will try the drug or a placebo
for a year.
Those on the trial will be taught
how to self-inject the drug three
times a day.
During that year the volunteers
will undergo multiple tests
A vaccine made from the Zika virus has been
used to kill brain cancer cells. In a study at the
University of Texas, mice with glioblastoma brain
tumours that were injected with the Zika-derived
virus lived for 50 days (the average survival is
usually 30 days), reports the journal mBio.
including brain scans to check on
any shrinkage, and blood tests to
check on SAP levels.
Professor Pepys stresses that it
won’t be ‘some miracle cure — but
what we hope is that it might halt
the disease’.
The drug is also being tested
in a separate trial on those with
amyloidosis — a rare potentially
fatal disease in which amyloid
builds up in organs throughout the
body.
Clive Ballard, a professor of
age-related diseases at Exeter
University, believes that in
Alzheimer’s it may be that amyloid
is important early on in the
process and becomes less so later’.
This, he says, may explain why
previously amyloid-reducing drugs
have not shown much effect.
And it is why he believes that
miridesap may turn out to have a
preventative role. Lum
© Solo dmg media
Nose spray that calms a racing heart in minutes
By Pat Hagan
A
SPRAY squirted up the
nose could be a fastacting new treatment for
faulty heartbeats.
Tests show the spray
restores heart rate to
normal in less than three minutes,
compared with at least half an hour
with current medicines. Scientists
predict it could bring almost instant
relief to thousands of patients who
endure long and frightening episodes
where their pulse goes haywire.
The spray is designed to treat
supraventricular tachycardia (SVT),
a condition that affects more than
100,000 people in the UK, where the
heart suddenly starts to beat rapidly
due to an electrical abnormality in
the heart.
An attack can last several hours
and leave patients feeling dizzy
as the heart contracts too quickly
for its chambers to fill with blood
between beats, cutting blood flow to
the brain.
The heart has four chambers,
and the rate at which it beats is
controlled by the sinus node, a
group of nerves in the top-right
chamber, the right atrium.
It sends out electrical impulses
An attack can last several hours and
leave patients feeling dizzy as the heart
contracts too quickly for its chambers
to fill with blood between beats, cutting
blood flow to the brain.
Caption style to go ini n this space Caption style to go ini n this space
that kick-start each heartbeat.
The impulses travel to an area
called the atrioventricular node.
This node slows them down to
allow the bottom two chambers
(the ventricles) to fill with blood.
Once the ventricles are full, the node
releases the impulses again to pump
blood out to the body.
In SVT, this process goes haywire.
As a result, heart rate can soar to
250 beats a minute.
The condition can affect quality
of life if episodes are frequent and
lengthy. Most patients are treated
with prescription drugs called
calcium channel blockers, which
slow down the rate at which heart
muscle contracts. But these can
take 30 minutes or more to have an
effect.
Patients may also undergo
catheter ablation — where an
electric probe is used to destroy
faulty cells in the heart.
The nose spray could be a more
convenient and speedier treatment.
It contains etripamil, a calcium
channel blocker already used as a
tablet to treat SVTt. Nasal sprays
act more quickly because the liquid
drug is rapidly absorbed by tiny
blood vessels lining the nasal cavity.
In a recent study, researchers
gave the spray to 104 patients. The
results, published in the Journal of
the American College of Cardiology,
showed the spray restored normal
heart rhythm in up to 95 per cent
of patients. More than half were
better within three minutes and one
patient was back to normal in less
than two minutes.
Researchers hope the spray could
become widely available in the next
couple of years.
Commenting on the new
treatment, Emily McGrath, a senior
cardiac nurse at the British Heart
Foundation, said: ‘This study shows
promising results.
‘If patients had access to a
nasal spray which relieved their
symptoms in a matter of minutes,
it would make a huge difference to
their lives.’
