Thursday, 7 September,
2000, 11:26 GMT 12:26 UK
Stem cell
Injection for stroke on the way
By BBC News Online's Jonathan Amos
UK scientists are to trial a single injection therapy for stroke
patients using stem cells next year.
The researchers hope the treatment will help restore brain function and
any personality lost by the patients.
If successful, the scientists plan to develop similar approaches for
treating Parkinson's disease and Alzheimer's.
Dr John Sinden, of ReNeuron
Limited, told the British Association's Festival of
Science: "The trial will involve a small number of patients but we
expect that within six years we will have a drug on the market."
The injection will use neural stem cells, "master cells" that
have yet to develop into specialised brain tissue.
...
In the laboratory, ReNeuron has shown that the stem cells will develop
into different and important brain cell types. When injected into the
brain, the cells migrate to areas of damage and start to repair it.
"The damaged adult brain still retains the capacity to use stem
cells. So what we've been doing is developing human neural stem cells that
we can inject into the brain for the brain to then use for
regeneration." ...mer/more...
Relaterte linker / Related links
- Adult Brain Stem Cells Multiply In
Vitro
Autologue, adult, neurons
- ReNeuron's
Cell
Transplantation
Centre
for Neuro Skills
Rewiring
the Damaged Brain
A study by Adelaide University scientists suggesting that the brain can
be 'rewired' could lead to a new therapy for stroke victims. The study
shows that healthy brain areas may be recruited to take over the functions
of areas damaged by stroke or trauma.
Observations of patients who suffer stroke or brain injury and regain
only limited function had led to a view of the brain as 'hard wired,' with
neural circuits laid down by puberty and remaining unchanged thereafter.
Among other things, the brain's cortex controls voluntary movement,
speech and reasoning. Research now suggests that neural connections of the
cortex are not fixed, but continuously modified by experience and
learning.
Earlier studies have revealed that practising a simple finger movement
can change the size of the area of motor cortex that controls specific
finger muscles, and even alter its neural connections.
In blind Braille readers, the cortical area for the reading finger is
much larger than for a non-reading finger. Amputees show the reverse
effect; cortical areas of missing muscles being taken over by those that
are unaffected.
In a study published in Experimental Brain Research, researchers from
the Department of Physiology at Adelaide University have discovered that
stimulating the nerve from a muscle to the brain can alter the size of
responses from the area of cortex that supplies the muscle. Furthermore,
these changes last for some time after the stimulation has stopped.
"Our findings are quite exciting as they have implications for
understanding phenomena such as skill learning and motor memory" said
Dr. Mike Ridding, a Florey Postdoctoral Fellow and lead investigator on
the study, "It also suggests new directions for developing potential
therapeutic approaches to disordered brain function in such debilitating
conditions as stroke."...
mer/more...
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Melbourne, Australia
Keeping
you informed…
Q: What are embryonic stem
cells?
A: Embryonic stem cells are derived
from very early embryos. They are “totipotent” – that is, they are
capable of generating all types of cell in the body during normal
development. Working with embryonic stem cells from mice, scientists are
trying to understand the chemical signals needed to generate nerve, blood
and other cell types.
Q: What are adult neural
stem cells? Why are they important?
A: Adult neural stem cells have been
identified in the human brain in small numbers. It seems that adult neural
stem cells may have the ability to develop into mature neurons or nerve
cells. If a person suffers a particular brain injury or has a
neurodegenerative disease such as Alzheimer’s or Parkinson’s, normal
brain function is impaired because nerve cells die progressively. Such
diseases might be treated effectively if a patient’s own neural stem
cells could be activated to develop into new nerve cells.
Q: What is the current
stage of research into adult neural stem cells? What happens next?
A: Adult neural stem cells from the
brains of mice can now be identified and separated from other nerve cells.
This allows the scientists to begin the search for molecules that can
activate them to replace nerve cells lost after disease. Since the brains
of mice are in many ways quite similar to human brains, scientists believe
that their findings will be directly applicable to human adult neural stem
cells. To verify this, research is also being undertaken using human brain
tissue that has been removed during routine brain surgery, with the
consent of the patients involved. When a trial drug has been developed, it
will be tested on mice and human brain tissue to assess its effectiveness
and any side effects. When a drug is found to be effective with minimal
side effects, human trials may then begin – subject, as always, to
strict ethical approval and regulation by various independent authorities.
Source:
http://srs.wehi.edu.au/education/FAQ/stem_cells_FAQ.html
Science
Notes 2001
- By
- Louisa
Dalton
-
B.S.,
biochemistry, Brigham Young University
After three surgeries to open up the
blood vessels feeding his heart and three more for the arteries of his
legs, Douglas Cummings knows the routine. “It’s not an unpleasant
procedure at all,” says the 63-year-old Californian. “They administer
a tranquilizer. The doctor makes a very quick puncture in the groin. You
feel a little sting. It’s not much more than a shot.” The doctor
threads a small, limp balloon into the clogged artery and inflates it to
flatten the fat lining the vessel wall. It’s an easy, one-day operation.
But for the majority of cardiovascular patients, this procedure, called
angioplasty, is merely a stop-gap measure. It widens the narrowed passage,
but it doesn’t get rid of the blockage that’s already there, and it
doesn’t stop further build-up. Within six months, 10 to 30 percent of
patients require angioplasty again. As the fatty plaque deposits in the
vessels increase, patients may even require the far more drastic
open-heart surgery. And all too often, it’s just a matter of time before
a chunk of plaque from one narrowed artery breaks off and completely stops
up another artery, prompting a heart attack or stroke.
That’s why Cummings signed up to
try a new therapy this time—a therapy that scours the insides of clogged
arteries. ...mer/more...
Brazilians
to Widen Stem-Cell Study in Strokes
Av
Andrei Khalip
RIO DE JANEIRO,
Brasil (Reuters) - Brasililianske leger, som tilførte stamceller i
benmarg til hjernen hos en slagpasient uttalte fredag, at de vil prøve
behandlingen på flere etter å ha sett tegn på at det kan ha hjulpet
pasienten til å friskne til.
Dr. Hans Fernando
Dohmann, som er forskningskoordinator ved Hospital
Pró-Cardíaco (”the
Pro-Cardiac Hospital”) i Rio de Janeiro, fortalte Reuters at et fullt
testprogram med 15 pasienter nå vil bli igangsatt for å undersøke om
stamceller virkelig kan hjelpe slagrammede.
Dohman sa at selv om
pasientens bedring også kunne ha skjedd av seg selv, så var det godt
mulig at stamcellene hadde hjulpet til. Benmarg er en rik kilde til voksne
stamceller, som er blodceller som har beholdt evnen til å vokse til et
bredt spektrum av celletyper inkl. hvite blodceller og hjerteceller.
”Det vi synes er
mest spennende, er at det er biologisk aktivitet (i det området av
hjernen, som ble skadet av slaget)... at injiseringen av celler ikke forårsaket
noen elektiske forstyrrelser og at det det ikke oppsto noen
betennelsesreaksjon,” sa Dohman.
Forskningen utføres
i samarbeide med Det føderale universitetet i Rio de Janeiro.
”Vi har ikke sett
rapporter om slike eksperimenter andre steder, så vi antar at vi er de første,
” la Dohman til.
Pasienten, en 54 år
gammel kvinne, fikk et slag, som gikk
ut over den dominerende delen av hjernen i august. Hun mistet
bevegelsesevnen på høyre side av kroppen og kunne ikke forstå andre
mennesker, eller kommunisere med dem.
Benmarg-celler fra
hennes egen kropp ble langsomt injisert i den midtre cerebral-arterien
gjennom et kateter den 5. dagen etter slaget. Etter 17 dager, ble hun
utskrevet med gjenvunnet førlighet, oppfatningsevne og noe taleevne, med
ytterligere fremskritt rapportert i de følgende månedene.
I september sa
Dohmans forsker-team at tester viste at benmargceller kan få pasienters døende hjerter til å tilfriskne
til og generere
små nye arterier og nytt muskelvev, en behandling som en dag kan komme til å
gjøre mange hjertetransplantasjoner unødvendige.
Fire av de fem
hjertepasientene i studien hadde ikke lenger behov for
hjertetransplantasjon, etter å ha blitt behandlet med stamceller.
Voksne stamceller,
som dem i benmargen benyttes allerede i behandlingen av flere sykdommer.
De er forskjellige fra foster-stamceller, som forskere tror kan ha ennå
større medisink potensiale. Imidlertid har bruk av fosterstamceller blitt
møtt med motstand av moralske årsaker, siden å skaffe dem tilveie,
betyr at menneskelige fostre må tilintetgjøes.
©
Reuters 2004. All Rights Reserved.
-----
Dato: Fredag 19.11.2004-11-20
Kilde: http://www.reuters.com/newsArticle.jhtml?type=healthNews&storyID=6871057
-----
For egen del vil jeg tilføye at voksne stamceller fra egen benmarg jo
tilhører kroppen og derfor ikke gir avstøtningreaksjoner fra
immunsystemet, noe som vil kunne bli et stort problem med fremmede
stamceller fra fostre og navlestrenger, som injiseres. Det er altså mye
som taler for "voksne" stamceller selv om de ikke på
langt nær er så "fleksible og tilpasningsdyktige" som
fosterceller
Trond
14. Aug. 2005
A korean medical research team has made progress in treating cerebral infarction by transplanting healthy marrow stem cells into dead brain cells.
Professors Rha Hyoung-kyun and Lee Jong-wook of the medical college of the Catholic University of Korea said that they have performed brain blood vessel bypass surgeries on five cerebral infarction patients and transplanted their stem cells since February, and seen great improvement in the paralysis symptoms and speech disorders of three of them.
The research The research team abstracted mononuclear cells containing stem cells after extracting 200 cubic centimeters (cc) of marrow from the cerebral infarction patients’ pelvises.
Then they performed bypass surgeries on the patients to make blood flow in the part of the brain with the cerebral infarction, and injected 1 cc of stem cells each at some 10 damaged regions of the brain.
Two weeks after the surgery, the researchers injected an additional 30 cc of stem cells at the spots through the blood vessels made by the bypass surgery, and have observed the progress for six to eight months.
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Annen
interessant medisinsk forskning / Other medical research of general
interest
Cancer: Spontaneous regression
Kreft: Spontan regresjon
Scientists
Develop Colony of Mice That Fight Off Virulent Cancer
WINSTON-SALEM, N.C. – Scientists at the Comprehensive Cancer Center of
Wake Forest University have developed a colony of mice that successfully
fight off virulent transplanted cancers.
"The mice are healthy, cancer-free and have a normal life
span," the 10-member team reported in the Proceedings of the National
Academy of Sciences online edition to be published the week of April 28.
The transplantation of the cancer cells in these special mice provokes
a massive infiltration of white blood cells that destroy the cancer, said
Zheng Cui, M.D., Ph.D., associate professor of pathology at Wake Forest
University Baptist Medical Center and the lead scientist
"The destruction of cancer cells by these leukocytes is rapid and
specific without apparent damage to normal cells," Cui said.
"These observations suggest a previously unrecognized mechanism by
which the body can fight off cancer."
The discovery of a genetic protection from cancer in mice "may
have potential for better therapy or prevention of cancer in people,"
the team said. It also could help explain why some people are protected
against cancer despite prolonged and intense exposure to carcinogens..
The discovery also could help solve another mystery. For years,
scientists have been searching for the mechanism that permits spontaneous
regression of human cancers without treatment. Cui said these cases are
well-documented, but occur rarely. The new mouse colony gives the team the
opportunity to study the mechanism in an animal model. ...mer/more...
News-Medical.Net...
Medical
News
Medical Research News
Published: Thursday, 21-Oct-2004
Researchers are conducting a
groundbreaking new study that may help stroke patients regain greater use
of their hands or arms through treatment with electrical stimulation.
Preliminary results of the
feasibility study that precedes this new study have shown that the use of
electrical stimulation, called motor cortex stimulation, may be both safe
and effective, according to Robert Levy, M.D., Ph.D., a neurosurgeon at Northwestern
Memorial Hospital in Chicago. Dr. Levy presented this feasibility
trial data at the Congress of Neurological Surgeons Wednesday in San
Francisco.
The trial showed that study
participants - stroke survivors suffering impaired hand or arm movement -
who underwent physical rehabilitation accompanied by motor cortex
stimulation showed greater improvement than participants who received
physical rehabilitation alone. Twenty-four subjects participated in the
feasibility study, 12 in the electrical stimulation group and 12 in the
control group. "Participants in the electrical stimulation group
experienced meaningful motor recovery gains," Dr. Levy says.
The study, sponsored by Northstar
Neuroscience, Inc., is close to completing the follow-up period.
Ongoing and further research is needed to validate these findings. Other
sites in the study were the University
of Illinois-Chicago, Rush
University Medical Center, University
of Arizona, Wayne
State University, University
of Minnesota and Kansas
University.
"It is our hope that by
stimulating the surface of the brain we can permanently reverse paralysis
and rekindle patients' function, returning them to their normal
lifestyle," says Dr. Levy, who is a professor at the Feinberg School
of Medicine at Northwestern University and who is leading the study at
Northwestern Memorial, which is being conducted in tandem with the
Rehabilitation Institute of Chicago. "Unfortunately, when patients
have had a stroke, there is not much we can currently offer beyond
physical rehabilitation to improve their motor functions."
Researchers are testing the new
surgical procedure, involving the implantation of tiny investigational
electrodes on the surface of the brain, in hopes of "jump
starting" the growth of new nerve fibers, or retraining a new area of
the brain to take over functions impaired by stroke damage.
...mer/more....
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