Tuesday, July 31, 2007

Adult Stem Cell Successes: Patients and Doctors to Speak Out

Adult Stem Cell Successes: Patients and Doctors to Speak Out

This is a good list of some great things that are being done with adult stem cells. It is probably being used in the old and tired and wrong-headed argument that since adult stem cells are being successfully used in therapy embryonic stem cells are not necessary and take resources from successful techniques. This is a false idea generally. It also has the dangerous limitation that when embryonic stem cells are shown to provide theraputic value in some specific situations the ignorance of the argument can be pointed out.

Tissue scaffolds can replace knockout mice



Genetically modified animals play a huge role in helping researchers to understand the role of specific genes in human disease. Now, Paul Genever at the University of York, UK, and his colleagues are developing an alternative based on human tissue, that could cut the number of animals used in research.


The team has already grown a 3D "tissue scaffold" from mesenchymal stem cells taken from human bone marrow, and is now trying to "knock out" individual genes in the stem cells, enabling them to discover the precise roles the missing genes play. Genever's team is just one of those to receive a grant from non-animal medical research charity the Dr Hadwen Trust, in Hitchin, UK.





Link

This is an example of ways stem cells will speed up developments in other areas of medicine.


Tags: ,


Powered by Qumana


Monday, July 30, 2007

Stem cells may mend a broken heart


The study, which was done on mice, shows that stem cells play a limited, but significant role in repairing damaged hearts. However, it remains unclear whether it is heart cells that are doing the repair, or cells from elsewhere in the body.


Richard Lee of the Harvard Medical School in Boston and colleagues genetically engineered mice so their heart muscle cells could be stained with a fluorescent protein.


Around 80 per cent of the heart muscle cells in young mice picked up the stain. As the mice aged, this level remained the same, which the researchers say demonstrates that heart muscle cells are not normally replaced in life.


However, when they induced heart attacks in the mice, the number of stained cells dropped to 70 per cent, suggesting that new muscle cells are formed in response to injury.



Link

This article implies that hearts have a limited ability to regenerate themselves.  More must be found out.


Tags: , , ,



Powered by Qumana


Friday, July 27, 2007

Nano mechanism to control protein

Link

UCLA scientists have created a mechanism at the nanoscale to externally control the function and action of a protein.

“We can switch a protein on and off, and while we have controlled a specific protein, we believe our approach will work with virtually any protein,” said Giovanni Zocchi, assistant professor of physics at UCLA, member of the California NanoSystems Institute and leader of the research effort. “This research has the potential to start a new approach to protein engineering.”

The research, published in the journal Physical Review Letters, potentially could lead to a new generation of targeted “smart” pharmaceutical drugs that are active only in cells where a certain gene is expressed, or a certain DNA sequence is present, Zocchi said. Such drugs would have reduced side effects. The research, federally funded by the National Science Foundation, also may lead to a deeper understanding of proteins’ molecular architecture

The first applications Zocchi foresees for the new molecules are as amplified molecular probes. Currently it is difficult for scientists to study a single live cell and find what gene it is expressing, but with an amplified molecular probe, in principle one could inject the probe into a single cell and detect that the cell is expressing a particular gene, Zocchi said.




It seems to me that external switching of proteins could be weaponized into a very selective poison. Like all extremely powerful techniques, this one has the potential to kill.

Saturday, July 21, 2007

Benefits of stem-cell engraftment may not last


The good news is that real, beating cardiomyocytes can be grown from undifferentiated stem cells, and large quantities of these cells with distinctly human characteristics can be obtained from human embryonic stem cells, as Mummery's talk proved. These differentiated cells will permit screens for drugs that bolster the numbers of cardiomyocytes produced and that help cardiomyocytes engraft and survive. Thus, although this progress may not signal the arrival of effective therapies, it may mark the true beginning of their development.


Link



The good news is also that the real work of heart repair is beginning.  The tough answers are beginning to come out.  Now, we can suspect that varying results might be caused by mis-labeling cells. Now, we know that the heart is a difficult but not impossible place to use stem cells, and that stem cells can form heart cells.



Tags: , , ,


Powered by Qumana


Tuesday, July 17, 2007

Benefits of stem-cell engraftment may not last

The Article covers some of the road blocks, there seem to be many, to heart repair using stem cells.




Not only do hearts recover poorly after injury, the prevalence of and morbidity from heart damage is high. Not surprisingly, cardiac regeneration is seen as among the most important applications of stem cell research. But although cell replacement therapy, or the successful engraftment of stem cells, works for bone marrow transplantation, this kind of cell therapy will be much more difficult in solid organs, at least according to results, presented at the June 2007 meeting of the ISSCR. Indeed, not only does heart tissue fail to promote integration of transplanted cardiomyocytes, it may even provide a hostile environment.



Link


Tags: , ,



Powered by Qumana