Communist
30th January 2010, 05:04
see also here (http://www.sciencedaily.com/releases/2010/01/100114081158.htm).
==========================
=================
Early Signs of Alzheimer's Are in the Eye (http://www.newscientist.com/article/dn18385-early-signs-of-alzheimers-are-in-the-eye.html)
by Jessica Hamzelou (http://newscientist.siruna.com/DSTWAR/Transcoder/_http/www.newscientist.com/search;jsessionid=492890E9610A7860FAC02ED08D147693 ?rbsection1=life&rbtype2=News&offset=0&rbauthors=Jessica+Hamzelou)
14 January 2010
Your eyes reveal a lot about you, and now that includes
the health of your brain. A new way of counting dying
eye cells could allow Alzheimer's disease to be
diagnosed and treated in its early stages.
Many neurological diseases - including Alzheimer's,
Parkinson's and Huntington's - involve the death of
neurons in the brain, but these events are extremely
hard to detect.
"It's difficult to diagnose these conditions before
considerable damage has taken place, because the
symptoms don't show up straight away," says Francesca
Cordeiro at University College London.
However, this cell death also tends to extend to cells
at the back of the eye, where it is much easier to
detect abnormalities. So Cordeiro and her colleagues
set about creating a way of detecting these eye neuron
deaths.
Exploding cells
Cell death can occur in one of two ways - a tidy
"suicide" known as apoptosis, or a messy cell
"explosion" called necrosis. In neurological disorders,
most neurons die by apoptosis early in the disease,
whilst necrosis happens later on.
In order to distinguish between these two types, the
researchers used a green dye that binds to a protein
expressed by cells undergoing apoptosis, and a red one
that binds to the insides of exploded cells.
The team injected the dyes into the eyes of healthy
mice and mice with a form of Alzheimer's disease and
waited until any unbound dye was washed away. Then the
researchers peered into the back of the mice's eyes
using an ophthalmoscope - the microscope that
optometrists use to look at human eyes.
Adding filters to the ophthalmoscope allowed the
researchers to see the dyes fluorescing as differently
coloured dots, each one announcing the death of a cell.
Cell rescue
They found that there were many more dots of both
colours in the mice with Alzheimer's than in healthy
mice, an indication that more cells were dying in both
ways in the eyes of these mice. Over time, they found
that as Alzheimer's progressed, the number of green
dots decreased and red dots increased.
The group hope that their technique could help doctors
and opticians to diagnose Alzheimer's and other
neurological diseases earlier than is currently
possible.
It might also be possible to use the technique to work
out how far a disease has progressed, allowing doctors
to prescribe the therapy that is most appropriate to
each patient.
"If most of the dying cells are undergoing apoptosis,
the disease is likely to be in an early stage, and
these cells could potentially be rescued," says
Cordeiro.
In the mice, her team managed to reverse the process of
apoptosis in eye cells that had started undergo it, by
giving them the Alzheimer's drug memantine.
Safe tagging
"If this method can be translated to humans, it would
be a major advance in our research tools," says Helen
Danesh-Meyer, professor of ophthalmology at the
University of Auckland in New Zealand. "I would be very
positive about using this new technique in my patients
if it became readily available."
However, Denise Valenti, an optometrist at Harvard
Vanguard Medical Associates, based in Braintree,
Massachusetts, is not convinced about a clinical
application.
"Techniques that involve tagging or injections can
create issues of access as well as cost and safety,"
she says. But she says the research is "very relevant,
especially for developing more effective animal studies
of drugs".
Cordeiro says the group hopes to develop a safe marker
that can be administered as eye drops and to test the
imaging technique in people later this year.
Journal reference: Cell Death and Disease, DOI:
10.1038/cddis.2009.3
_____________________________________________
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--------------------
--------------
---------
------
----
--
Portside aims to provide material of interest
to people on the left that will help them to
interpret the world and to change it.
==========================
=================
Early Signs of Alzheimer's Are in the Eye (http://www.newscientist.com/article/dn18385-early-signs-of-alzheimers-are-in-the-eye.html)
by Jessica Hamzelou (http://newscientist.siruna.com/DSTWAR/Transcoder/_http/www.newscientist.com/search;jsessionid=492890E9610A7860FAC02ED08D147693 ?rbsection1=life&rbtype2=News&offset=0&rbauthors=Jessica+Hamzelou)
14 January 2010
Your eyes reveal a lot about you, and now that includes
the health of your brain. A new way of counting dying
eye cells could allow Alzheimer's disease to be
diagnosed and treated in its early stages.
Many neurological diseases - including Alzheimer's,
Parkinson's and Huntington's - involve the death of
neurons in the brain, but these events are extremely
hard to detect.
"It's difficult to diagnose these conditions before
considerable damage has taken place, because the
symptoms don't show up straight away," says Francesca
Cordeiro at University College London.
However, this cell death also tends to extend to cells
at the back of the eye, where it is much easier to
detect abnormalities. So Cordeiro and her colleagues
set about creating a way of detecting these eye neuron
deaths.
Exploding cells
Cell death can occur in one of two ways - a tidy
"suicide" known as apoptosis, or a messy cell
"explosion" called necrosis. In neurological disorders,
most neurons die by apoptosis early in the disease,
whilst necrosis happens later on.
In order to distinguish between these two types, the
researchers used a green dye that binds to a protein
expressed by cells undergoing apoptosis, and a red one
that binds to the insides of exploded cells.
The team injected the dyes into the eyes of healthy
mice and mice with a form of Alzheimer's disease and
waited until any unbound dye was washed away. Then the
researchers peered into the back of the mice's eyes
using an ophthalmoscope - the microscope that
optometrists use to look at human eyes.
Adding filters to the ophthalmoscope allowed the
researchers to see the dyes fluorescing as differently
coloured dots, each one announcing the death of a cell.
Cell rescue
They found that there were many more dots of both
colours in the mice with Alzheimer's than in healthy
mice, an indication that more cells were dying in both
ways in the eyes of these mice. Over time, they found
that as Alzheimer's progressed, the number of green
dots decreased and red dots increased.
The group hope that their technique could help doctors
and opticians to diagnose Alzheimer's and other
neurological diseases earlier than is currently
possible.
It might also be possible to use the technique to work
out how far a disease has progressed, allowing doctors
to prescribe the therapy that is most appropriate to
each patient.
"If most of the dying cells are undergoing apoptosis,
the disease is likely to be in an early stage, and
these cells could potentially be rescued," says
Cordeiro.
In the mice, her team managed to reverse the process of
apoptosis in eye cells that had started undergo it, by
giving them the Alzheimer's drug memantine.
Safe tagging
"If this method can be translated to humans, it would
be a major advance in our research tools," says Helen
Danesh-Meyer, professor of ophthalmology at the
University of Auckland in New Zealand. "I would be very
positive about using this new technique in my patients
if it became readily available."
However, Denise Valenti, an optometrist at Harvard
Vanguard Medical Associates, based in Braintree,
Massachusetts, is not convinced about a clinical
application.
"Techniques that involve tagging or injections can
create issues of access as well as cost and safety,"
she says. But she says the research is "very relevant,
especially for developing more effective animal studies
of drugs".
Cordeiro says the group hopes to develop a safe marker
that can be administered as eye drops and to test the
imaging technique in people later this year.
Journal reference: Cell Death and Disease, DOI:
10.1038/cddis.2009.3
_____________________________________________
---------------------------------------
---------------------------------
--------------------------
--------------------
--------------
---------
------
----
--
Portside aims to provide material of interest
to people on the left that will help them to
interpret the world and to change it.