All concepts, explanations, trials, and studies have been
re-written in plain English and may contain errors. I am
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Stem Cells

August 19, 2003 - Stem cells may be responsible for the
heart cell formation that is seen in enlarging human hearts.
The theory was that increases in adult heart mass could
only happen through increased heart cell size, not through
formation of more heart muscle cells. Now we know that
heart muscle cells can increase in number when the heart
is under stress.
	Dr. Piero Anversa studied heart tissue from 36
people with aortic stenosis who were having heart valves
replaced and from 12 controls collected within 24 hours
after death.
	The increased heart mass that occurs with aortic
stenosis is from heart cells increasing in size and from
increasing numbers of cells. Researchers found that this
heart muscle cell formation seems to come from stem cells
that were specifically "heart" stem cells, destined to
become heart muscle cells.
	These stem cells increased 13 times in number in
hearts with aortic stenosis compared to controls. The
heart's enlarged state seemed to stimulate these cells to
become heart muscle cells.
	That these primitive stem cells respond to heart
stress by becoming new heart muscle cells makes researchers
wonder if the heart can in fact regenerate damaged parts of
itself.

Source: Reuters Health
Source: Proc Natl Acad Sci USA 2003;August 18th early
        edition:000-000.

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Trial of adult stem cells in CHF shows benefit

April 26, 2004 - The idea behind this and other stem cell
trials for heart failure is simple in theory. Bone marrow
is taken from a person's hip bone. Stem cells that may work
in the heart are then extracted from the marrow. These
stem cells are injected into damaged areas of that same
person's heart. The stem cells hopefully change into real
heart muscle cells. Those cells should improve the heart's
ability to pump more strongly, and might encourage growth
of new blood vessels to better supply the heart with
oxygen.

The trial was done in South America. In this randomized
trial, 20 CAD patients with EFs less than 36% having
bypass surgery were studied. Each group was 8 men and 2
women. The control group only had bypass surgery. The
treatment group had both bypass surgery and stem cell
injection.
	Patients all had an echo, thallium stress test 
(SPECT), and a heart cath before surgery. These tests
identified areas of the heart damaged by lack of blood
supply. The images were used to map where to inject the
stem cells.
	Patients were put under anesthesia. Bone marrow
was taken from their hip bones. While bypass surgery was
being done, stem cells that influence blood vessel and
heart muscle growth (CD34+ and CD45- cells) were
extracted from other cells in their bone marrow. After
bypass surgery was finished, the stem cells were injected
into about 30 places in the heart where it was damaged.
	There were no serious adverse events. Follow-up
was at one, 3 and 6 months with echo, SPECT, and cath.
All bypasses were still open at 6 months as shown by cath.
Each follow-up showed improvement in blood flow in areas
injected with stem cells. EF for stem-cell patients
improved:

Follow-up	Control group	Treatment group

Before surgery	31%		29%
One month	36%		42%
Three months	37%		46%
Six months	37%		46%

Researchers studied tissue samples taken before and after
surgery to look for a protein that is a marker of "gap
junctions." Gap junctions are important for communication
between cells. The marker (called Connexin 43) is usually
reduced in CHFers. Six months after surgery, there was an
increase in this marker in treated patients compared to
controls.
	Researchers don't know if the increase was from
growth of new heart muscle cells or from the stem cells
coaxing existing cells to stop hibernating and start
working again.
	Lead author Dr. Amil Patel said that patients who
got stem cells improved functional class by almost two,
from class 3 or 4 to class one or class 2.

Source: University of Pittsburgh press release
Source: April 25, 2003 annual meeting of the American
        Association for Thoracic Surgery.