Pumping Marvellous

Progress in repairing Hearts

The Heart by Pumping Marvellous

Scientists have turned back the hands of a biological clock to rejuvenate ageing and damaged human heart cells. Using stem cells, they reset a molecular mechanism that determines the rate at which cells age. Although the work on human cells was confined to the laboratory, the same technique has been successfully tested in mice and pigs.Researchers in the US managed to get new heart tissue to grow in the animals in just four weeks. They hope the advance will lead to new treatments for heart failure.

“Modifying aged human cardiac cells from elderly patients adds to the cell’s ability to regenerate damaged heart muscle, making stem cell engineering a viable option,” said lead scientist Dr Sadia Mohsin, from San Diego State University in California.

In the laboratory studies, Dr Mohsin’s team worked on heart tissue surgically removed from elderly patients. Stem cells from the samples were treated with a growth protein called PIM-1.

The effect was to boost activity of an enzyme called telomerase, which has a direct impact on ageing. The research was presented at a meeting of the American Heart Association in New Orleans and published in the Journal of the American College of Cardiology.

Beating Skin Cells

A very interesting piece of research which could transform the way we currently treat Heart Failure

Scientists have for the first  time succeeded in taking skin cells from patients with heart  failure and transforming them into healthy, beating heart tissue  that could one day be used to treat the condition. The researchers, based in Haifa, Israel, said there were  still many years of testing and refining ahead. But the results  meant they might eventually be able to reprogram patients’ cells  to repair their own damaged hearts. “We have shown that it’s possible to take skin cells from an  elderly patient with advanced heart failure and end up with his  own beating cells in a laboratory dish that are healthy and  young – the equivalent to the stage of his heart cells when he  was just born,” said Lior Gepstein from the Technion-Israel  Institute of Technology, who led the work.
The researchers, whose study was published in the European  Heart Journal on Wednesday, said clinical trials of the  technique could begin within 10 years. Heart failure is a debilitating condition in which the heart  is unable to pump enough blood around the body. It has become  more prevalent in recent decades as advances medical science  mean many more people survive heart attacks.
Researchers have been studying stem cells from various  sources for more than a decade, hoping to capitalise on their  ability to transform into a wide variety of other kinds of cell  to treat a range of health conditions. There are two main forms of stem cells – embryonic stem  cells, which are harvested from embryos, and reprogrammed “human  induced pluripotent stem cells” (hiPSCs), often originally from  skin or blood.

TISSUES BEATING TOGETHER
Gepstein’s  team took skin cells from two men with heart  failure – aged 51 and 61 – and transformed them by adding three  genes and then a small molecule called valproic acid to the cell  nucleus. They found that the resulting hiPSCs were able to  differentiate to become heart muscle cells, or cardiomyocytes,  just as effectively as hiPSCs that had been developed from  healthy, young volunteers who acted as controls for the study. The team was then able to make the cardiomyocytes develop  into heart muscle tissue, which they grew in a laboratory dish  together with existing cardiac tissue. Within 24 to 48 hours the two types of tissue were beating  together, they said. In a final step of the study, the new tissue was  transplanted into healthy rat hearts and the researchers found  it began to establish connections with cells in the host tissue. “We hope that hiPSCs derived cardiomyocytes will not be  rejected following transplantation into the same patients from  which they were derived,” Gepstein said. “Whether this will be  the case or not is the focus of active investigation.” Experts in stem cell and cardiac medicine who were not  involved in Gepstein’s work praised it but also said there was a  lot to do before it had a chance of becoming an effective  treatment. “This is an interesting paper, but very early and it’s  really important for patients that the promise of such a  technique is not over-sold,” said John Martin a professor of  cardiovascular medicine at University College London. “The chances of translation are slim and if it does work it  would take around 15 years to come to clinic.” Nicholas Mills, a consultant cardiologist at Edinburgh  University said the technology needs to be refined before it  could be used for patients with heart failure, but added: “These  findings are encouraging and take us a step closer to …  identifying an effective means of repairing the heart.”

Heart Repair Shop

Stem cells grown from patients’ own cardiac tissue can heal damage once thought to be permanent after a heart attack, according to a study that suggests the experimental approach may one day help stave off heart failure.

In a trial of 25 heart-attack patients, 17 who got the stem cell treatment showed a 50 percent reduction in cardiac scar tissue compared with no improvement for the eight who received standard care. The results, from the first of three sets of clinical trials generally needed for regulatory approval, were published today in the medical journal Lancet.

“The findings in this paper are encouraging,” Deepak Srivastava, director of the San Francisco-based Gladstone Institute of Cardiovascular Disease, said in an interview. “There’s a dire need for new therapies for people with heart failure”

The study, by researchers from Cedars-Sinai Heart Institute in Los Angeles and Johns Hopkins University in Baltimore, tested the approach in patients who recently suffered a heart attack, with the goal that repairing the damage might help stave off failure. While patients getting the stem cells showed no more improvement in heart function than those who didn’t get the experimental therapy, the theory is that new tissue regenerated by the stem cells can strengthen the heart, said Eduardo Marban, the study’s lead author.

“What our trial was designed to do is to reverse the injury once it’s happened,” said Marban, director of Cedars- Sinai Heart Institute. “The quantitative outcome that we had in this paper is to shift patients from a high-risk group to a low- risk group.”

Minimally Invasive

The stem cells were implanted within five weeks after patients suffering heart attacks. Doctors removed heart tissue, about the size of half a raisin, using a minimally invasive procedure that involved a thin needle threaded through the veins. After cultivating the stem cells from the tissue, doctors reinserted them using a second minimally invasive procedure. Patients got 12.5 million cells to 25 million cells.

A year after the procedure, six patients in the stem cell group had serious side effects, including a heart attack, chest pain, a coronary bypass, implantation of a defibrillator, and two other events unrelated to the heart. One of patient’s side effects were possibly linked to the treatment, the study found.

While the main goal of the trial was to examine the safety of the procedure, the decrease in scar tissue in those treated merits a larger study that focuses on broader clinical outcomes, researchers said in the paper.

Heart Regeneration

“If we can regenerate the whole heart, then the patient would be completely normal,” Marban said. “We haven’t fulfilled that yet, but we’ve gotten rid of half of the injury, and that’s a good start.”

While the study resulted in patients having an increase in muscle mass and a shrinkage of scar size, the amount of blood flowing out of the heart, or the ejection fraction, wasn’t different between the control group and stem-cell therapy group. The measurement is important because poor blood flow deprives the body of oxygen and nutrients it needs to function properly, Srivastava said.

“The patients don’t have a functional benefit in this study,” said Srivastava, who wasn’t not involved in the trial. The technology is being developed by closely held Capricor Inc., which will further test it in 200 patients for the second of three trials typically required for regulatory approval.

Stem cells taken from a patient’s own heart have, for the first time, been used to repair damaged heart tissue, researchers claim. The study, published in the Lancet, was designed to test the procedure’s safety, but also reported improvements in the heart’s ability to pump blood.

The authors said the findings were “very encouraging”

Other experts said techniques with bone marrow stem cells were more advanced and that bigger trials were needed. The scientists say this is the first reported case of cardiac stem cells being used as a treatment in people after earlier studies had shown benefits in animals.

The preliminary trial was on patients with heart failure who were having heart bypass surgery. During the operation, a piece of heart tissue, from the right atrial appendage, was taken. While the patient was being sown up, researchers isolated cardiac stem cells from the sample and cultured them until they had about two million stem cells for each patient. The cells were injected about 100 days later. Doctors measured how efficiently the heart was pumping using the left ventricle ejection fraction – what percentage of blood was leaving one of the heart’s main chamber with every beat.  Dr Roberto Bolli University of Louisville said “We believe these finding are very significant”

In the 14 patients given the treatment, the percentage increased from 30.3% at the beginning of the trial, to 38.5% after four months.

There was no change in the ejection fraction in the seven patients who were  not injected with stem cells.

“Our results indicate that cardiac stem cells can markedly improve the  contractile function of the heart.”

However the heart is not the only source of potentially useful stem cells. Trials have already taken place using stems cells from bone marrow.

Prof Anthony Mathur, from Barts and the London School of Medicine and Dentistry, and Prof John Martin, from University College London, are already conducting large randomised clinical trials. Prof Peter Weissberg British Heart Foundation “This is positive, but the crucial next steps are to see whether this improvement is confirmed in the final completed trial”

Prof Mathur said of the cardiac stem cell study: “Caveats very much apply. It’s a phase one trial so while the early results are great and promising, they need to design a big study to see if the results translate.”

He also cautioned that improvements in ejection fraction were not the same as increasing survival or quality of life.

Prof Martin said he was “concerned” that the seven patients in the control group showed no improvement in ejection fraction, which would normally be expected, and that they were not given a sham treatment to account for the placebo effect.

He said that was acceptable when just testing a procedure’s safety, but not when looking at effectiveness, which relies on the difference between the treated and control groups. Prof Peter Weissberg, medical director at the British Heart Foundation, argued that the improvement in heart function was similar to those in other studies.

“This is positive, but the crucial next steps are to see whether this improvement is confirmed in the final completed trial, and to understand whether the cells are actually replacing damaged heart cells or are secreting molecules that are helping to heal the heart,” he added.

Dr Bolli argues that stem cells from the heart might be more useful as “their natural function is to replace the cells that continuously die in the heart due to wear and tear”. He hopes to start the next phase of clinical trials in 2012

Excerpt taken from BBC Health Website

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Optimistic – We are!

The Sunday Times has reported the following information reference fixing damaged hearts. It goes to show that research and more interestingly practical steps are being made on stem cell development for injured hearts.

American researchers believe that artificial hearts developed in laboratories could start beating within weeks. The experiment is a major step towards the first ‘grow-your-own’ heart. The organs were created by removing muscle cells from donor organs to leave behind tough hearts of connective tissue. Researchers then injected stem cells which multiplied and grew around the structure, eventually turning into healthy heart cells. Dr Doris Taylor, an expert in regenerative medicine at the University of Minnesota in Minneapolis, said: ‘The hearts are growing, and we hope they will show signs of beating within the next few weeks.” ‘There are many hurdles to overcome to generate a fully functioning heart, but my prediction is that it may one day be possible to grow entire organs for transplant.’

Patients given normal heart transplants must take drugs to suppress their immune systems for the rest of their lives.

This can increase the risk of high blood pressure, kidney failure and diabetes.

If new hearts could be made using a patient’s own stem cells, it is less likely they would be rejected.

So how are they doing it…

The lab-grown organs have been created using these types of cells – the body’s immature ‘master cells’ which have the ability to turn into different types of tissue. The experiment follows a string of successes for researchers trying to create spare body parts for transplants.

In 2007, British doctors grew  a human heart valve using stem  cells taken from a patient’s  bone marrow

Grow your own heart

A year later, scientists grew a beating animal heart for the first time.

Dr Taylor’s team have already created beating rat and pig hearts. Although they were too weak to be used in animals, the work was an important step towards tailor-made organs. In their latest study, reported at the American College of Cardiology’s annual conference in New Orleans, researchers created new organs using human hearts taken from dead bodies. The scientists stripped the  cells from the dead hearts with a powerful detergent, leaving ‘ghost heart’ scaffolds made from the protein collagen.

The ghost hearts were then injected with millions of stem cells, which had been extracted from patients and supplied with nutrients. The stem cells ‘recognised’ the collagen heart structure and began to turn into heart muscle cells. The hearts have yet to start beating – but if they do, they could be strong enough to pump blood.

However, the race to create a working heart faces many obstacles. One of the biggest is getting enough oxygen to the organ through a complex network of blood vessels. Scientists also need to ensure the heart cells beat in time. Dr Taylor indicated that: ‘We are a long way off creating a heart for transplant, but we think we’ve opened a door to building any organ for human transplant.’

We are of course will be following the developments carefully especially with the British Heart Foundations “Mending Broken Hearts Campaign” in aid of raising £50 million for research into mending broken hearts.

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Can Heart Damage Improve after Stem Cell Treatment

According to a small clinical trial published in Circulation Research: Journal of the American Heart Association it can.

We hope you can read behind the medical speak but this is definitely a step in the right direction.

Researchers have shown for the first time that stem cells injected into enlarged hearts reduced heart size, reduced scar tissue and improved function to injured heart areas.

Researchers said that while this research is in the early stages, the findings are promising for the more than five million Americans who have enlarged hearts due to damage sustained from heart attacks. These patients can suffer premature death, have major disability and experience frequent hospitalizations. Options for treatment are limited to lifelong medications and major medical interventions, such as heart transplantation, according to Joshua M. Hare, M.D., the study’s senior author and professor of medicine and director of the Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, University of Miami in Miami, Florida.

Using catheters, researchers injected stem cells derived from the patient’s own bone marrow into the hearts of eight men (average age 57) with chronically enlarged, low-functioning hearts.

“The injections first improved function in the damaged area of the heart and then led to a reduction in the size of the heart. This was associated with a reduction in scar size. The effects lasted for a year after the injections, which was the full duration of the study,” Hare said.

Specifically, researchers found:

• Heart size decreased an average of 15 percent to 20 percent, which is about three times what is possible with current medical therapies.
• Scar tissue decreased by an average of 18.3 percent.
• And there was dramatic improvement in the function, or contraction, of specific heart areas that were damaged.

“This therapy improved even old cardiac injuries,” Hare said. “Some of the patients had damage to their hearts from heart attacks as long as 11 years before treatment.”

The researchers had used two different types of bone marrow stem cells in their study — mononuclear or mesenchymal stem cells. The study lacked the power to determine if one type of cell works better than the other. All patients in the study benefited from the therapy and tolerated the injections with no serious adverse events.

Hare’s study assessed the effect of stem cell injections differently from other studies of post-heart attack stem cell treatment. His team measured contractility, scar size and structural changes of the heart.

“Studies of bone marrow cell therapy for ischemic heart disease in animals have shown improved ejection fraction (the amount of blood the heart can pump). However, this measurement has not reliably translated to early phase studies in humans,” Hare said. “Ejection fraction may not be the best way to measure the success of stem cell therapy in the human heart.”

Hare also said their findings suggest that patients’ quality of life could improve as the result of this therapy because the heart is a more normal size and is better functioning. “But, we have yet to prove this clinical benefit – this is an experimental therapy in phase one studies. These findings support further clinical trials and give us hope that we can help people with enlarged hearts.”

Co-authors are Adam R. Williams, M.D.; Barry Trachtenberg, M.D.; Darcy L. Velazquez, R.N., B.S.N.; Ian McNiece, Ph.D.; Peter Altman, Ph.D.; Didier Rouy, M.D., Ph.D.; Adam M. Mendizabal, M.S.; Pradip M. Pattany, Ph.D.; Gustavo A. Lopera, M.D.; Joel Fishman, M.D., Ph.D.; Juan P. Zambrano, M.D. and Alan W. Heldman M.D. Author disclosures are on the manuscript.

The University of Miami Interdisciplinary Stem Cell Institute, BioCardia (makers of the catheter used) and the National Institutes of Health funded the study.

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Mending Broken Hearts

Britain’s leading heart charity the British Heart Foundation(BHF) has launched a £50 million ($80 million) research project on Tuesday into the potential of stem cells to regenerate heart tissue and “mend broken hearts”.

Scientists leading the work for the British Heart Foundation said they hope that within the next decade they may have experimental drugs in development that would give certain kinds of cells in the heart the ability to regenerate tissue, repair damage and therefore combat heart failure.

The ability of heart tissue to regenerate already occurs in some animals, such as zebrafish, which can regrow portions of their own hearts if they are damaged.

At a briefing in London to launch a “mending broken hearts” fundraising campaign, scientists said research into stem cells and developmental biology may in future make this possible in people too.

“Scientifically, mending human hearts is an achievable goal and we really could make recovering from a heart attack as simple as getting over a broken leg,” said Professor Peter Weissberg, medical director at the BHF. Scientists in the United States reported last year that they had been able to turn structural heart cells into beating cells by identifying genes that, in a developing embryo, turn an immature cell into a beating heart cell or cardiomyocyte. One of the British teams, led by Professor Paul Riley of the Institute of Child Health at University College London (UCL) has already found a natural protein, called thymosin beta 4, that plays a role in developing heart tissue.

He said his researchers had already had some success in using this protein to “wake up” cells known as epicardial cells in mice with damaged hearts.

“We hope to find similar molecules or drug-like compounds that might be able to stimulate these cells further,” he told reporters at the briefing.

Another team of researchers at Imperial College London will be looking at a group of rare latent stem cells that can be harvested and then grown in the laboratory.

These cells are highly active in developing hearts and can grow into new functioning tissue, but something in them gets switched off soon after humans are born, meaning that the heart is no longer able to repair any damage, said Professor Michael Schneider, who leads this team.

His researchers will be trying to find ways of re-activating the cells in a controlled and safe way, so that they are able to repair damaged heart tissue but will not grow out of control.

“One strategy would be to give a drug that would activate this kind of process,” he said, adding that this “requires more knowledge about what signals trigger these cells”.

Weissberg said if the research was as successful as they hoped, it could one day reduce or even eliminate the need for heart transplants for patients whose hearts are damaged.

Cardiac Stem Cell Developments

Scientists have developed a scaffold that supports the growth and integration of stem cell-derived cardiac muscle cells-a feat that offers hope for achieving what the body can’t do- mending broken hearts.

The scaffold, built by engineers and physicians at the University of Washington, supports the growth of cardiac cells in the lab and encourages blood vessel growth in living animals.

“Your body can’t make new heart cells, but what if we can deliver vital new cells in that damaged portion of the heart?” he added.

Ratner and his colleagues built a tiny tubular porous scaffold that supports and stabilizes the fragile cardiac cells and can be injected into a damaged heart, where it will foster cell growth and eventually dissolve away.

The new scaffold not only supports cardiac muscle growth, but potentially accelerates the body’s ability to supply oxygen and nutrients to the transplanted tissue.

Eventually, the idea is that doctors would seed the scaffold with stem cells from either the patient or a donor, then implant it when the patient is treated for a heart attack, before scar tissue has formed.

Ratner’s scaffold is a flexible polymer with interconnected pores all of the same size.

This one also includes channels to accommodate cardiac cells’ preference for fusing together in long chains.

“We’re very optimistic that this scaffold will help keep the muscle cells alive after implantation and will help transition them to working heart muscles,” said a co-author.

The scaffold is made from a jelly-like hydrogel material developed by first author, UW bioengineering doctoral student Lauran Madden.

A needle is used to implant the tiny (third of a millimeter wide by 4 millimeters long) scaffold rods into the heart muscle.

But the scaffold can support growth of larger clumps of heart tissue, said Madden.

The next steps will involve adjusting the scaffold degradation time so that the scaffold degrades at the same rate that cardiac cells proliferate and that blood vessels and support fibers grow in, and then implant a cell-laden scaffold into a damaged heart.

“What we have now is a really good system going in the dish, and we’re working to transition it to in the body,” said Madden.

The study has been published in the Proceedings of the National Academy of Sciences. (ANI)

Cells Morphed to Muscle May Lead to Therapy for Heart Failure

This information has been taken from Bloomberg and has been written by Rob Waters. It really is an excellent article in demonstrating how much research is being put into stem cell research.

“Tissue from the hearts of mice morphed into muscle cells with the ability to beat and form electrical connections, in an experiment that may lead to new therapy for more than 5 million Americans with heart failure.

Connective-tissue cells called fibroblasts make up about half the cells in the heart. Researchers led by Deepak Srivastava, director of the Gladstone Institute of Cardiovascular Disease in San Francisco, said they used a trial- and-error process to identify three genes able to turn fibroblasts into heart muscle.

The technique may enter clinical trials in as little as five years to test whether damaged areas of patients’ hearts can regenerate, Srivastava said. Heart failure has no cure and will cost the U.S. health-care system $39 billion this year, according to the American Heart Association, based in Dallas.

“It points to a whole new way of potentially doing therapy,” said Chad Cowan, an assistant professor in the department of stem cell and regenerative biology at Harvard University in Cambridge, Massachusetts. “This gives you the idea that you can take those fibroblasts, re-educate them to become heart muscle and thereby repair someone’s heart.”

The research, published today in the journal Cell, follows work by Shinya Yamanaka, of Kyoto University in Japan, who in 2007 identified genes that transformed skin cells into the equivalent of embryonic stem cells.

Dying Cells

After a heart attack, the blood supply to the organ is cut off, leaving sections without the oxygen they need. Cells in the oxygen-starved areas die, form scar tissue and no longer contract properly, impairing the heart’s pumping. Patients with this kind of damage, known as heart failure, can become exhausted by walking or climbing stairs.

Damaged parts of the heart can’t regenerate because they have no ability to make new muscle cells, Srivastava said in a telephone interview on Aug. 3. Researchers have hoped that stem cells might regrow heart muscle.

Efforts to transplant adult stem cells into patients’ hearts have led to modest improvements at best because the stem cells failed to form new heart muscle, Srivastava said. His technique may provide an alternative to stem-cell transplants by tapping into and converting a supply of cells already in the heart.

“The ability to take cells that are already in the organ and harness them to generate new muscle has the potential for regeneration from within,” he said. “People living with heart failure would have a chance to lead better lives. People who can’t walk up a flight of stairs might be able to do that with ease.”

Most Advanced

Srivastava’s research is the most advanced example so far of a new approach to altering the function and destiny of cells, a process known as directed differentiation. Instead of getting cells to revert back to an immature stem-cell state, then converting them to a particular cell type, scientists try to turn one kind of mature cell directly into another.

Transplanting heart cells made from embryonic stem cells carries the risk that immature cells able to form tumors also may be transferred, said Kenneth Chien, director of the Cardiovascular Research Center at Massachusetts General Hospital in Boston. An advantage of Srivastava’s technique is that it eliminates the risk from the immature cells, Chien said.

While Srivastava’s work is an “important scientific advance,” there are questions, Chien said.

“Will this work in human cells?” he said. “Will this work ‘in vivo,’” inside an animal or person?

Identifying Genes

Srivastava’s team began by identifying 14 genes that are especially active in heart muscle cells, and used a virus to insert them into fibroblasts. If the corresponding genes in the fibroblasts were turned on, the cells would glow green. Then they removed each gene one at a time until they found three that could convert the fibroblasts on their own.

In a second experiment, one day after inserting the three genes into fibroblasts, they injected the fibroblasts into the hearts of mice. Within two weeks, the fibroblasts turned into heart muscle cells that formed connections with other heart cells and transmitted electrical signals.

Yamanaka’s technique worked with mouse and human cells and Srivastava said is method may do so as well. A next step for both techniques will be to find chemicals that can perform the same function as the genes he used to transform the cells, cutting the risk of cancer that genes and viruses carry.

Since researchers have made progress finding chemicals to replace the genes used by Yamanaka, Srivastava said he is confident they can be found for his method too.

If chemicals that perform this function can be found, they may be used in stents, tiny wire-mesh devices that are inserted into arteries to prop them open. The stents would release the chemical into the heart, prompting the cells to transform, Srivastava said.

I thought I would share this with you. It is a very simple explanation of where we are with Stem Cell research. It is a press release by Cryo-Cell International INC

Dr. Joshua Hare believes medicine is close to a goal long thought to be impossible: healing the human heart.

The way to get there? Stem cells.

“These could be as big as antibiotics were in the last century,” said Hare, who leads the University of Miami ‘s new Stem Cell Institute. “Stem cells have the potential to have that kind of impact. Diseases like heart attacks, strokes, kidney failure, liver failure and Heart Failure — we will be able to transition them into things you live with.”

Hare spends his days peering through powerful microscopes, recruiting scientists from top universities and attending to patients betting on improving their conditions through his clinical trials.

Stem cells, only one-thousandth the size of a grain of sand, are the master cells of the body, the source from which all other cells are created.

The most basic are embryonic stem cells, which are “totipotent,” meaning they can divide into any other type of cell — heart tissue, brain tissue, kidney tissue — all 220 cells that exist in the human body. They’re controversial because when they are harvested, the embryo is destroyed, ending potential life.

But coming into view are new kinds of stem cells — immature adult stem cells that can be extracted from bone marrow, from organs such as the heart or kidney or even from the skin. These can be taken without destroying embryos.

While researchers until recently believed adult stem cells were limited because they could develop only into cells similar to them — bone marrow cells only into cord blood stem cells, for example — evidence is growing that they, too, may become the tissue for hearts, brains, kidneys and other organs.

Hare expands on these developments:

Q. You’ve said that the basic idea behind your work is that a healthy human body is creating stem cells all the time to keep its organs healthy, and you’re trying to tap into this ability to expand its powers?

A: That’s the theory. It does sound fantastic. Actually, it happens in the body all the time, in tiny amounts. In our blood, to survive, we have red blood cells that carry oxygen, white cells that regulate the immune system and platelets, which are tiny cells that seal off cuts. They come from stem cells in the bone marrow. The marrow is the source for all red blood cells, platelets and some white blood cells.

The cells circulate in the blood all the time. Unless there’s a signal that says, “Come here and do this,” they will just keep circulating. If you get a cut, the cells will be recruited to that area to do what they do.

Q: Could such cells heal a heart attack all by themselves?

A: Experts believe the ability of the body to heal itself without help is limited. The system can slowly replace missing cells here and there, over a lifetime. But it’s not designed to repair a massive injury like a heart attack. That’s where we as doctors can intervene.

Q: In fact, you are intervening. You’ve led two studies at Johns Hopkins University and University of Miami in which you have harvested immature, or “mesenchymal” adult cord blood stem cells from the bone marrow, multiplied them many times in the lab, then injected them into the damaged heart. Is the idea that the bone marrow stem cells become heart cells?

A: This is where the biology gets somewhat murky. We don’t understand all the elements. We do have evidence that the cells differentiate, develop into healthy heart tissue.

Q: And this could be true with a damaged liver, kidney or brain?

A: In theory.

Q: You’ve said other kinds of adult stem cells are at work too?

A: Many cells are involved in the body’s attempts to heal itself. Some are from blood cells from bone marrow. But also, within the organs themselves, there are resident precursor cells that are stem cells. They’re sitting there like front-line soldiers in an injury. We think those stem cell cord blood collections that talk to each other and can go out and do healing. So we are engaging in a new study that will look at cardiac stem cells.

We can take pieces of heart tissue during surgery, multiply the stem cells in the lab and have a large amount to give back to the patient.

Q: Could an organ stem cell from, say, heart tissue, become a stem cell in the brain or kidney?

A: It’s possible, but not certain. We’re interested in studying how many degrees of freedom these cells have.

Q: And now researchers are getting stem cells even from the skin?

A: We’re starting to look at that. We know that stem cells in the skin replenish every 120 days. Researchers a year ago took regular stem cells from the skin and genetically reprogrammed them by introducing four genes. They were able to turn them into stem cells with a nearly unlimited capacity.

I hope enjoyed the read