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http://www.mprize.org/index.php?ctype=news&pagename=blogdetaildisplay&BID=2006042-17093018&detaildisplay=Y
Brief Quote:
Rejuvenating Aging Stem Cells ... Or Not
Posted on 04-17-2006 09:30:18 by Reason
You might recall work
published last year that suggested aging, non-responsive stem cells
responsible for muscle maintenance and repair could be brought
back into operation by suitable biochemical cues. Here is another
relevant study:
Satellite-cell pool size does matter: Defining the myogenic potency
of aging skeletal muscle
The deteriorating in
vivo environment is thought to play a major role in reduced stem
cell function with age. The capacity of stem cells to support tissue
maintenance depends not only on their response to cues from the
surrounding niche, but also on their abundance. Here, we investigate satellite
cell (myogenic stem cell) pool size and its potential to participate
in muscle maintenance through old age. The numbers and performance of
mouse satellite cells have been analyzed using molecular markers that
exclusively characterize quiescent satellite cells and their progeny as
they transit through proliferation, differentiation and generation of
reserve cells. The study establishes that abundance of resident
satellite cells declines with age in myofibers from both fast- and
slow-twitch muscles. Nevertheless, the inherent myogenic potential of
satellite cells does not diminish with age. Furthermore, the aging
satellite cell niche retains the capacity to support effective
myogenesis upon enrichment of the mitogenic milieu with FGF.
Altogether, satellite cell abundance, but not myogenic potential,
deteriorates with age. This study suggests that the population of
satellite cells that participate in myofiber maintenance during routine
muscle utilization is not fully replenished throughout life.
...
It is interesting to speculate on the sort of cell therapies that will
be developed to repair the damage that aging inflicts upon us -
intermediary therapies, really, that will be developed and used prior to
technologies capable of preventing this damage from occurring, or
repairing it in situ as it happens. It is not unreasonable to look at the
state of stem cell science, bioinformatics
and gene therapy
today and predict that medical researchers of 2020 will be culturing new
stem cell populations for individuals, correcting age-related damage to
genetic and cellular material before returning the new cells to the body.
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http://www.news-medical.net/?id=17347
Brief Quote:
The Notch effect steers stem cells into cells of the nervous system
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| Medical Science News |
| Published: Thursday, 13-Apr-2006 |
Embryonic stem cells have the potential to make all 200 cell
types in the body. The challenge is to restrain this diversity and
uncover the signals that commit stem cells to a single specialized
function. Sally Lowell and her colleagues have now established
that Notch gives embryonic stem cells the critical push towards
becoming cells of the nervous system.
The researchers show that when Notch is activated in embryonic
stem cells, up to 90% of the cells in the dish become nerve cells.
In any colony of embryonic stem cells, under normal conditions,
many never become cells of the nervous system: they spontaneously
change into other cell types or remain as embryonic stem cells.
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http://www.washingtontimes.com/metro/20060213-112517-5048r.htm
Brief Quote:
Rebuilding a damaged heart
By Jen Waters
THE WASHINGTON TIMES
February 14, 2006
Dr. Joshua Hare and his colleagues at the Johns Hopkins University School of
Medicine and its Heart Institute in Baltimore are hoping that dying hearts can
be made new. Because of recent research, many doctors believe the heart has
regenerative capacity.
Since March 2005, Dr. Hare, professor of medicine at the
school and institute, has been enrolling heart attack patients in a trial to see
if mesenchymal stem cells from bone marrow can regenerate a damaged heart. He
previously performed trials with pig hearts.
"The primary purpose of the study is to access the
safety of the procedure," Dr. Hare says. "We're thrilled with the
progress we've made. We should finish in 2006."
Five years ago, most doctors never would have considered
using stem cell therapy to help heart attack victims, but today, many experts
say the procedure could redefine the field of cardiology. Though much research
is still needed, cardiologists are excited about the possibilities it could
provide.
After people have a heart attack, if they are enrolled
in Dr. Hare's study, they are infused with mesenchymal stem cells from bone
marrow and followed for six months.
...
Making a new therapy available to the public is a
difficult and heavily regulated process, Dr. Hare says.
...
"The big race is on to find the best kind of stem cell," Dr.
Marban says. "We can take human cells from the heart and put them in mice,
and it improves the hearts of mice that had heart attacks."
Significant regrowth in the hearts of mice takes three
weeks, he says. He estimates that it may take two to four months to have the
same effect in human hearts.
...
Further, cardiologists have begun to consider that stem
cell therapy may be used preventively.
"There is no question that stem cell treatments are
going to change the way we practice cardiology," Dr. Marban says. "The
benefit need not be limited to the heart."
...
Apart from stem cell therapy, new methods for surgery
are being explored, says Dr. David D. Yuh, associate professor of surgery and
director of cardiac surgical research and robotic cardiac surgery at the medical
school and institute.
There is an effort to do the same operations through
smaller incisions, he says, and robotic surgery for mitral valve repairs is
becoming less experimental and more widely adopted.
"The jury is still out as to whether or not the
current robot will endure," Dr. Yuh says. "It's still very expensive.
The learning curve is steep. Many surgeons have backed off for that
reason."
Most patients are pleased by the better cosmetic
results, he says.
...
"I fully believe the surgical instrument for the
next generation is an Xbox controller," Dr. Brown says.
...
Rebuilding a damaged heart - Metropolitan - The Washington Times, America's Newspaper
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http://www.thestar.com/NASApp/cs/ContentServer?pagename=thestar/Layout/Article_Type1&c=Article&cid=1144187410760&call_pageid=970599119419
Brief Quote:
Stem cells may help our bodies heal themselves
Research aimed at degenerative diseases Labs across Canada take part in effort
Apr. 6, 2006. 01:00 AM
ELAINE CAREY
STAFF REPORTER
...
As chief of research at The Hospital for Sick Children, Rossant is
collaborating with labs across Canada to see whether human embryonic stem
cells can be useful tools for treating degenerative diseases. Her lab at Sick
Kids is looking at trying to get stem cells to form blood vessels that could
be transplanted into the damaged tissue of patients with heart disease.
...
One of the cells produces myelin, the sheath that wraps around most of the
nerves in the body and that's lost in multiple sclerosis and many traumatic
brain and spinal cord injuries.
The lab, in collaboration with the Rick Hansen Centre for spinal cord injury
research in British Columbia, has shown that you can put those cells in
animals and they produce functional myelin that encourages the growth of nerve
cells that have been damaged and injured.
...
Dr. Peter Dirks' lab made the breakthrough discovery that a small number of
cells in a brain tumour control its growth. They have been able to take those
cells, inject them into mice and replicate the human brain tumour. That has
led to research to define what those cells are and what drugs can be used to
destroy them.
...
Work on cancer stem cells is being hotly pursued in almost every type of human
cancer, he says.
"That's the real challenge now, to figure out what makes them tick and
how to shut them down. We have to find the tumour cells that really
matter."
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