bone marrow stem cells can help rebuild weakened heart muscle
- From: Jim Carter <spamfree@xxxxxxxxx>
- Date: Wed, 28 Sep 2005 13:24:26 -0400
27 September 2005 -- For the first time, scientists have
discovered that injections of bone marrow stem cells can help
rebuild weakened heart muscle, thanks to a technique pioneered by
Dr. Amit Patel, one of the leaders in stem cell therapy for heart
disease, at the University of Pittsburgh Medical Center.
Stem cells are primal undifferentiated cells which retain the
ability to differentiate into other cell types. This ability
allows them to act as a repair system for the body, replenishing
other cells as long as the organism is alive. Medical researchers
believe stem cell research, also called regenerative medicine,
has the potential to change the face of human disease by being
used to repair specific tissues or to grow organs. Still, as
government reports point out, "significant technical hurdles
remain that will only be overcome through years of intensive
research."
Patel is director of the Center for Cardiac Cell Therapy at UPMC
and the University of Pittsburgh McGowan Institute for
Regenerative Medicine and is making the news these days with his
pioneering work. .
For example, recently, it was discovered that a Pennsylvania
woman with heart failure has significantly improved after
undergoing a stem cell treatment in Thailand via the direct
injection technique pioneered by Dr. Patel.
Jeannine Lewis suffered from non-ischemic cardiomyopathy. She was
in Class III-IV heart failure (the borderline of needing a heart
transplant) and on maximal oral medical therapy. After three
months, MRI and echocardiogram results showed improvement and
doctors have reclassified her to Class I heart failure ? a
significant improvement. Her shortening fraction and stroke
volume have also increased.
In May Lewis became the first patient in the world to receive
therapy using minimally invasive, direct cell injections to the
heart. Dr. Patel accompanied Lewis to Bangkok in order to oversee
her procedure.
Post-treatment, Lewis was in less pain and her exercise tolerance
had increased greatly, ?within weeks, my symptoms had greatly
decreased while my energy level simultaneously increased. I am
now able to clean my house, do my shopping and actively care for
and play with my young child.? Lewis said. The recent
quantitative test results now confirm what Lewis seems to have
known from the beginning.
It's unclear if the stems cells used in the UPMC trials might
become transformed into new heart muscle tissue or instead fuse
with the patients' own damaged cells to help them work better.
Alternatively, the stem cells could act like homing signals to
attract other repair substances to the heart.
Last month, Dr Patel launched a second clinical trial to see if
injections of bone marrow stem cells can improve the function of
a weakened heart.
The trial will involve patients with ischemic heart disease who
are scheduled for off-pump (beating heart) coronary artery bypass
grafting surgery. In addition to assessing the safety and
feasibility of using a patient's own stem cells as a potential
therapy for heart disease, researchers also will be trying to
determine just how many stem cells are needed to produce the best
results.
Patients who give their consent to participate will be randomized
to one of four treatment groups and neither they nor the
researchers will know into which group they are assigned until
the conclusion of the study. Researchers hope to enroll a total
of 24 patients ? six in each group ? who they will follow over
the course of one year.
"Stem cell therapy as an adjuvant to traditional bypass surgery
is the next step to help determine the best way to help very sick
heart failure patients. This is the first randomized study in the
U.S. to evaluate the combination of cell therapy with traditional
surgical revascularization and may help answer a number of key
questions," explained Dr. Patel.
''When you inject these cells in, they act like a homing beacon
to the heart," said Dr. Patel. ''The heart's just sending out an
SOS signal saying 'Here! Come help me,' " he said. The adult stem
cells then enlist other cells that deliver building blocks needed
to partially restore heart function.
"Standard surgical and catheter-based treatments are reasonably
effective for treating chest pain, reducing the risk of heart
attack and improving heart function. But none has the ability to
actually restore or repair damaged heart tissue. The aim of stem
cell therapy is to repopulate the ailing heart muscle with cells
that may help restore blood supply and help the heart regain its
ability to contract more effectively and efficiently," added Joon
S. Lee, M.D., clinical director of UPMC's Cardiovascular
Institute and assistant professor of medicine and associate
chief, division of cardiology, University of Pittsburgh School of
Medicine.
Various studies that have been conducted around the world,
including a limited number performed in the United States, have
suggested that when patients with heart failure receive stem
cells taken from their bone marrow, their hearts show signs of
improved function and recovery. However, most of these clinical
studies did not control for variables that may have influenced
patients' clinical improvements, and all but a very few were
designed as a randomized and double-blinded trial, the most
rigorous method for evaluating clinical interventions.
UPMC researchers expect to ask about 75 patients to participate
in the new trial in order to enroll and randomize six patients
into each of the four study groups. A person not involved in the
study will select a card from 24 numbered one through four to
determine which group a patient is to be assigned. Then, with the
patient under anesthesia, Dr. Patel's team will harvest bone
marrow from the patient's hipbone. While the bypass operation is
taking place, the patient's stem cells will be isolated from the
bone marrow and prepared accordingly, depending on the patient's
random assignment. Patients may be randomly selected to one of
three groups that will receive varying concentrations of stem
cells or to a fourth group receiving their own blood serum void
of stem cells.
Though researchers have speculated that human embryonic stem
cells might someday be used to regenerate either the heart muscle
or the arteries feeding the heart muscle, the bone marrow stem
cells being used in the UPMC studies likely would not work that
way, Patel said. Rather, the stem cells may help the heart by
fusing with injured cells and helping them function better.
Another, even more likely mechanism -- but harder to prove -- is
that the injected stem cells secrete growth factors or other
substances that harness and redirect the body's healing powers.
Dallas-born Patel?s interest in Stem Cell research stems from
having seen "so many cardiac patients that we couldn't help with
surgery or with traditional medications." Patel, 33, earned his
undergraduate degree (B.S. 1993) and graduate (M.S. 1994) from
Youngstown State University and then went on to earn his M.D.
(1998) with distinction from Case Western Reserve University. He
received additional training at Baylor University Medical Center
and University of Pittsburgh Medical Center. Among the many
awards Patel has received, is the Most Distinguished Resident
Award from the American Association of Physicians of Indian
Origin (AAPI) at the 21st Annual Convention, Orlando, FL.
francisassisi@xxxxxxxxxxx
--
The opinions expressed are mine alone. My employer would crap if it
were known what I say here.
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