One Blog for the Kids!: Stem cell

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Monday, December 19, 2011

Broken heart fix with stem cells

Posted: 15 November 2011

PARIS: Stem cells from heart-attack patients helped improve blood-pumping ability and restore vitality in cardiac muscle, according to a small trial published on Monday.

It is the first time patients have been given an infusion of their own
cardiac stem cells in the aim of solving the impact of heart failure rather than simply treating the symptoms of it.

The findings are so promising that the study's chief investigator said a potential "revolution" was in the offing if larger trials succeeded.

Stem cells are infant cells that develop into the specialised tissues of the body.

They have sparked great excitement as they offer hopes of rebuilding organs damaged by disease or accident.

The new study, published online in The Lancet, tested cardiac stem cells on 16 patients who had been left gravely ill as a result of an acute myocardial infarction.

The index used for cardiac health is called the left ventricular ejection fraction (LVFV), which calculates the capacity of the left ventricle to expel blood in the space of a heartbeat.

For a person in normal health, the LVFV is 50 percent or higher.

Among the study patients, though, this had fallen to 40 percent or lower. At such a threshold, shortness of breath and fatigue are chronic and often disabling.

The stem cells were isolated from a coronary artery that had been removed when the patients underwent a coronary bypass.

Within four months of treatment, the LVFV rose by 8.5 percent and after a year by 12 percent - four times what the researchers had expected.

Scans of the patients' hearts also showed a reduction in the area of tissue that had been scarred by the infarction, a discovery that challenges conventional belief that once scarring occurs, heart tissue is permanently dead.

The volunteers also reported a substantial improvement in quality of life, and there were no significant side effects.

Seven patients with similar heart problems were enrolled as "controls", to serve as a comparison. There was no change in their LVFV, in scar tissue or in their quality of life.

"The results are striking," said lead investigator Roberto Bolli of the University of Louisville, Kentucky.

"While we do not know why the improvement occurs, we have no doubt now that 1/8LVFV 3/8 increased and scarring decreased.

"If these results hold up in future studies, I believe this could be the biggest revolution in cardiovascular medicine in my lifetime."

The team is seeking funding to launch a larger, or Phase II, trial - the second in the normal three-phase process of assessing a new treatment for safet and effectiveness.

Previous stem-cell work on heart damage has used cells harvested from bone marrow.

The interest in cardiac stem cells is that they are self-renewing, produce daughter cells and differentiate into all types of cells in the heart.

The results were presented concurrently at a meeting of the American Heart Association in Orlando, Florida.

-AFP/pn

Taken from ChannelNewsAsia.com; source article is below:
Broken heart fix with stem cells

Wednesday, June 3, 2009

Chinese researchers create pig stem cells

Posted: 03 June 2009 1700 hrs

Chinese researchers create pig stem cells

PARIS: Chinese researchers said on Wednesday they had created versatile stem cells from pigs, a groundbreaking achievement that could open up new paths for combatting human disease.

Doctors led by Lei Xiao, of the Shanghai Institute of Biochemistry and Cell Biology, took adult cells taken from a pig's ear and bone marrow and reprogrammed them so that they became so-called pluripotent stem cells.

These are cells that, like the coveted stem cells found in embryos, can differentiate into any type of cell in the body.

It is a technical exploit because until now, no-one has been able to achieve reprogramming using somatic cells -- cells that do not come from sperm or eggs -- from a hooved animal.

But the main interest lies in fundamental medical research, as it offers the hope of using the pig as a test bench for disease and a source of transplant material, Xiao said.

The pig is close to the human in many biological functions and with some organs that are similar in size.

"We could use embryonic stem cells or induced stem cells to modify the immune-related genes in the pig to make the pig organ compatible to the human immune system," he said in a press release.

"Then we could use these pigs as organ donors to provide organs for patients that won't trigger an adverse reaction from the patient's own immune system."

Another possibility would be to modify genes in lines of pig stem cells so that they replicate flaws in human genes that cause diabetes and other diseases, he suggested.

The modified stem cells could then be used to generate pigs with the same disorder, thus providing researchers with a model on which to test new therapies.

The Chinese team tucked a basket of reprogramming genes inside a virus to infect the adult cells and return them to their naive, versatile state.

Tests on the cells showed they were capable of differentiating into the three fundamental layers of tissue in an early embryo.

The paper is published in the Journal of Molecular Cell Biology.

Work on similar lines is being carried out on human cells, first achieved in 2007 by Shinya Yamanaka of Kyoto University.

- AFP/yt

From ChannelNewsAsia.com; see the source article here.