Monday, October 23, 2006

The problem with stem cells

Nature has a story that explains the problems with attempted stem cell treatment of Parkinson's Disease, which always seems to be the disease most mentioned as being potentially curable by such treatment.

The problem is cancer caused as a side effect.

I also saw most of an SBS Insight program about therapeutic cloning and stem cell research a few weeks ago. It was interesting to see at least some medical experts expressing scepticism of stem cell treatment:

JENNY BROCKIE: Jack Martin, you're former director of St Vincent's Institute of Medical Research. Do you share this optimism about stem cell research?

JACK MARTIN, FMR. PROF. OF MEDICINE, MELBOURNE UNIVERSITY: No, I have to say I don't. And I would take issue with quite a number of things that Elizabeth Finkel has just said. She's implied that there has been proof of concept of efficacy of embryonic stem cell therapy in a number of diseases and mentioned Parkinson's disease, spinal cord injury and diabetes, and that is absolutely untrue. There are temporary and partial improvements in chemically induced Parkinson's disease in rodents and in a couple of monkey studies, and in no case has this been prolonged and in no case has it been a long enough.. It's either been associated with a serious complication of cancer teratoma formation or it's not been carried out for long enough to determine whether that's been avoided or not.

Of course, there were others present who were much more optimistic than this.

3 comments:

Anonymous said...

Embryoinic cells doe have a potentail. Here is a recent paper from Johns Hopkins;

Recovery from paralysis in adult rats using embryonic stem cells

Deshpande DM, Kim YS, Martinez T, Carmen J, Dike S, Shats I, Rubin LL, Drummond J, Krishnan C, Hoke A, Maragakis N, Shefner J, Rothstein JD, Kerr DA.
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-6965, USA.

OBJECTIVE: We explored the potential of embryonic stem cell-derived motor neurons to functionally replace those cells destroyed in paralyzed adult rats. METHODS: We administered a phosphodiesterase type 4 inhibitor and dibutyryl cyclic adenosine monophosphate to overcome myelin-mediated repulsion and provided glial cell-derived neurotrophic factor within the sciatic nerve to attract transplanted embryonic stem cell-derived axons toward skeletal muscle targets. RESULTS: We found that these strategies significantly increased the success of transplanted axons extending out of the spinal cord into ventral roots. Furthermore, transplant-derived axons reached muscle, formed neuromuscular junctions, were physiologically active, and mediated partial recovery from paralysis. INTERPRETATION: We conclude that restoration of functional motor units by embryonic stem cells is possible and represents a potential therapeutic strategy for patients with paralysis. To our knowledge, this is the first report of the anatomical and functional replacement of a motor neuron circuit within the adult mammalian host.

PMID: 16802299 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16802299&query_hl=2&itool=pubmed_docsum

Please also be informed that a company named Geron will start human clinical trials the first quarter in 2007 by using cells derived from human embryonic stem cells to treat acute spinal cord injuries. - hESC is known for their abilities to make neurons. Good stuff.

Anonymous said...

Here is more from Baylor College of Medicine. This also shows the potential embryonic stem cells have, see below.

I also did see the TV show, and this Martin does not tell everything, why would he not mention the Kerr study above or this study I am posting here. He must have known about it if he is a top notch researcher. So why does he act as the studies has not been performed? I feel he is full of shit and lying.

Novel stem cell technology promotes recovery after spinal cord injury

Using a new understanding of stem-cell technology, researchers at Baylor College of Medicine in Houston have identified a new way to promote recovery after spinal cord injury in rats, according to results published in a recent issue of the Journal of Biology.

The study reveals that rats recover from spinal cord injury following transplantation with immature support cells of the central nervous system. These support cells called astrocytes were generated from stem cells.

More... http://www.bcm.edu/fromthelab/vol05/is4/06may_n1.html

Steve said...

Thanks for the references. Will get around to them soon.