08-03-2018

HEALTH
THURSdaY, MaRCH 8, 2018
5
nice prize for
alzheimer’s work
a mother holding her lovely baby.
Photo: internet
is it shameful to breastfeed
in the open?
MiCHEllE RobERTS
Four dementia scientists have
shared this year's 1m Euro brain
prize for pivotal work that has
changed our understanding of
Alzheimer's disease.
Profs John Hardy, Bart De
Strooper, Michel Goedert, based in
the UK, and Prof Christian Haass,
from Germany, unpicked key protein
changes that lead to this most
common type of dementia. On getting
the award, Prof Hardy said he
hoped new treatments could be
found. He is donating some of his
prize money to care for Alzheimer's
patients.
Much of the drug discovery
research that's done today builds on
their pioneering work, looking for
ways to stop the build-up of damaging
proteins, such as amyloid and
tau. Alzheimer's and other dementias
affect 50 million people around
the world, and none of the treatments
currently available can stop
the disease. Prof Hardy's work
includes finding rare, faulty genes
linked to Alzheimer's disease. These
genetic errors implicated a build-up
of amyloid as the event that kickstarts
damage to nerve cells in
Alzheimer's.
This idea, known as the amyloid
cascade hypothesis, has been central
to Alzheimer's research for
nearly 30 years. Together with Prof
Haass, who is from the University
of Munich, Prof Hardy, who's now
at University College London, then
discovered how amyloid production
changes in people with rare inherited
forms of Alzheimer's dementia.
Prof Goedert's research at Cambridge
University, meanwhile,
revealed the importance of another
damaging protein, called tau, while
Prof De Stooper, who is the new
director of the UK Dementia
Research Institute at UCL, discovered
how genetic errors that alter
the activity of proteins called secretases
can lead to Alzheimer's
processes.
Dr David Reynolds, Chief Scientific
Officer at Alzheimer's Research
UK, said: "Our congratulations go
to all four of these outstanding scientists
whose vital contributions
have transformed our understanding
of the complex causes of
Alzheimer's disease. "The fact that
three of these researchers work in
the UK reflects the country's position
as a global leader in dementia
research."
Prof Hardy said he would be
donating around 5,000 euros of his
share of the 1m euros from the
Lundbeck Foundation to help campaigns
to keep Britain in the EU,
and called Brexit a "unmitigated
disaster" for scientific research. He
also pledged his thanks to all the
people with Alzheimer's who, over
the years, have volunteered to help
with dementia research.
CHiTRa RaMaSwaMY
Shock, horror! A woman has bared part of one of her
breasts (let's say 35% of total breast area) on a magazine
cover in the southern Indian state of Kerala. Not for the
sake of titillation but lactation: to feed a baby. The model
gazes out at the reader with a defiant half-smile. The
baby feeds on, blissfully unaware that its food source is
also an international site of objectification. The cover
line reads: "Mums tell Kerala: don't stare - we need to
breastfeed." The response? Lots of staring, debate, outrage,
accusations of sensationalism and one indecency
case launched against the magazine, Grihalakshmi.
Which is ironic because feeding a baby is pretty much
the definition of human decency.
The cover was inspired by a photo of an Indian
woman, Amritha, publicly breastfeeding her daughter,
which went viral on Facebook. Amritha says she was
told off for breastfeeding her baby in hospital and
advised that if she fed without covering her breasts, her
milk would dry up. But, before we start congratulating
ourselves for our more evolved attitudes, remember
that the UK has the lowest breastfeeding rates in the
world, and women are still not permitted to nurse in the
House of Commons chamber.
Breastfeeding is bloody hard work, and I write this
with my own seven-month-old on my breast, not for
authenticity's sake but because she is hungry. It takes
patience, practice, commitment, physical strength,
good humour, multiple tubes of Lansinoh cream, and
enough chutzpah to withstand the stares, unwanted
advice and general opprobrium that come your way
whenever you need to feed your baby while out and
about. This is why a third of women feel embarrassed
breastfeeding in public, according to one UK survey.
I've breastfed both my babies; my son until he was
nearly two (go on, judge me). This has meant feeding on
the bus, in cafes, on park benches, in front of my dad,
and - on one particularly fabulous occasion - on stage
while I was discussing Anne of Green Gables. I have felt
embarrassed, vulnerable and exposed. Once, I retreated
to the toilet. It's not easy whipping out an intimate and
sexualised part of your body that has doubled in size
and developed the ability to shoot multiple jets of hot
milk from its core. This should incite praise, compassion
and awe, as opposed to accusations of indecency.
The only shame in breastfeeding is in the misogynistic
attempt to turn the simple, free, loving and necessary
act of feeding our babies into a dirty secret.
alzheimer's disease brain (left) compared to normal (right).
Photo: Science Photo library
Human skin bacteria
could protect against
cancer
Professor Jeff gordon, one of the world's leading experts on the human microbiome, talks to his
students.
Photo: Mark Katzman
The surprising power of microbes
Ed Yong
'So, what's in the thermos?" I asked. I
was standing in a lift at Washington
University in St Louis, with Professor
Jeff Gordon and two of his students,
one of whom was holding a metal canister.
"Just some faecal pellets in tubes,"
she said. "They're microbes from
healthy children, and also from some
who are malnourished. We transplanted
them into mice," explained Gordon,
as if this was the most normal thing in
the world.
The lift doors opened, and I followed
Gordon, his students, and the thermos
of frozen pellets into a large room. It
was filled with rows of sealed chambers
made of transparent plastic. Peering
inside one of these chambers, I met the
eyes of one of the strangest animals on
the planet. It looked like just a mouse,
and that is precisely why it was so
weird. It was just a mouse, and nothing
more. Almost every other animal on
Earth, whether centipede or crocodile,
flatworm or flamingo, hippo or human,
is a teeming mass of bacteria and other
microbes. Each of these miniature
communities is known as a microbiome.
Every human hosts a microbiome
consisting of some 39 trillion microbes,
roughly one for each of their own cells.
Every ant in a colony is a colony itself.
Every resident in a zoo is a zoo in its
own right. Even the simplest of animals
such as sponges, whose static bodies
are never more than a few cells thick,
are home to thriving microbiomes.
But not the mice in Gordon's lab.
They spend their entire lives separated
from the outside world, and from
microbes. Their isolators contain everything
they need: drinking water, brown
nuggets of chow, straw chips for bedding,
and a white styrofoam hutch for
mating in privacy. Gordon's team irradiates
all of these items to sterilise them
before piling them into loading cylinders.
They sterilise the cylinders by
steaming them at a high temperature
and pressure, before hooking them to
portholes in the back of the isolators,
using connecting sleeves that they also
sterilise.
It is laborious work, but it ensures
that the mice are born into a world
without microbes, and grow up without
microbial contact. The term for this is
"gnotobiosis", from the Greek for
"known life". We know exactly what
lives in these animals - which is nothing.
Unlike every other mouse on the
planet, each of these rodents is a mouse
and nothing more. An empty vessel. A
silhouette, unfilled. An ecosystem of
one. Each isolator had a pair of black
rubber gloves affixed to two portholes,
through which the researchers could
manipulate what was inside. The gloves
were thick. When I stuck my hands in,
I quickly started sweating. I awkwardly
picked up one of the mice. It sat snugly
on my palm, white-furred and pinkeyed.
It was a strange feeling: I was
holding this animal but only via two
black protrusions into its hermetically
sealed world. It was sitting on me and
yet completely separated from me.
When I had shaken hands with Gordon
earlier, we had exchanged microbes.
When I stroked this mouse, we
exchanged nothing.
The mouse seemed normal, but it
was not. Growing up without microbes,
its gut had not developed properly - it
had less surface area for absorbing
nutrients, its walls were leakier, it
renewed itself at a slower pace, and the
blood vessels that supplied it with
nutrients were sparse. The rest of its
body hadn't fared much better. Compared
with its normal microbe-laden
peers, its bones were weaker, its
immune system was compromised,
and it probably behaved differently too.
It was, as microbiologist Theodor Rosebury
once wrote, "a miserable creature,
seeming at nearly every point to require
an artificial substitute for the germs it
lacks".
niCola daviS
A type of bacteria commonly found on
human skin produces a substance that
may help protect against skin cancer,
researchers have revealed. The scientists
say the surprise discovery regarding
a strain of Staphylococcus epidermidis
highlights the importance of the
community microbes found on and in
the body in preventing disease.
While it is not clear whether the
absence of this strain could increase the
risk of skin cancer in individuals, the
team say that it is possible the findings
might one day lead to preventive treatments
for patients. "The presence of
this strain may provide natural protection,
or it might be used therapeutically
to inhibit the growth of various forms of
cancer," said Prof Richard Gallo, a coauthor
of the research from the University
of California, San Diego.
The finding was somewhat serendipitous.
With previous research showing
that chemicals produced by Staphylococcus
species commonly found on
healthy human skin can kill off certain
harmful bacteria, the team looked at
numerous strains to explore their
antimicrobial powers.
Writing in the journal Science
Advances, Gallo and colleagues
describe how among their results, they
discovered a strain of Staphylococcus
epidermidis which produced a substance
that killed off a type harmful
bacteria responsible for infections such
as strep throat. While it was not the
only strain to do so, the chemical these
microbes produced was unusual,
boasting a structure similar to one of
the key components of DNA, called
adenine.
"The strain was originally detected in
a screen for antimicrobial activity, but
when we identified the nature of the
chemical produced by this strain we
proceeded with experiments to determine
if it might have activity against
tumours," said Gallo.
The researchers found that the
chemical, called 6-N-hydroxyaminopurine
(6-HAP), hindered the production
of DNA, with work in cell cultures
revealing that 6-HAP prevents several
types of tumour cells from growing
and multiplying.
By injecting mice with this substance,
the team found that 6-HAP is
not toxic. However, when melanoma
cells were introduced to mice, animals
which had received 6-HAP intravenously
ended up with tumours that
were more than 60% smaller than
those that had not received the substance.
The team also found application of
the 6-HAP-producing strain of Staphylococcus
epidermidis to the skin of
mice appeared to greatly reduce both
the number of pre-malignant skin
tumours formed when the creatures
were exposed to ultraviolet light, and
number of mice affected, compared to
those exposed to a strain that did not
produce the substance.
While Staphylococcus epidermidis is
commonly found on human skin, the
team say about 20% of the healthy
population is likely to have a strain
which produces 6-HAP. "Our study
found that it is common, but not on
everyone," said Gallo. Julian Marchesi,
professor of human microbiome
research at Cardiff University who was
not involved in the study, welcomed
the findings.
"This research further adds to a
growing understanding of how important
the human microbiota, and in this
case the skin microbiome, is to health.
We have evolved to need these
microbes and desperately need to
understand all the roles they play in
human biology and start to think more
The presence of Staphylococcus epidermidis may provide natural
protection against skin cancer. Photo: UC San diego Health
about what it is to be a human being,"
he said. "The next stage of this exciting
work, will be to translate it to human
clinical trials and show that this bacterially
produced chemical can protect
the host from skin cancers."