Slashdot Mirror
First Embryonic Stem Cell Clinical Trial Imminent
An anonymous reader writes "California-based Geron has announced that the first embryonic stem cell trial may be in the not-so-distant future. Tom Okarma, Geron's CEO, recently announced that the company will be seeking permission from the FDA to begin clinical trials. From the article: 'Geron's plan is to treat people that have acute spinal injuries with oligodendrocyte progenitor cells grown from human ESCs. Oligodendrocyte cells support neurons in the brain and spine by sheathing them in myelin, a fat that helps neurons to transmit signals.'"
I believe this was the result of propostion 71 that was passed in California last year. It allocated $3 billion over a period of ten years to fund stem cell research! Way to go California :)
http://religiousfreaks.com/ http://psychicfreaks.com/Ethanol does have an effect on transmission (specifically it reduces excitability and increases the effectiveness of GABA, an inhibitory neurotransmitter), but those are effects on action potential generation. Myelination from oligodendrocytes just increases the ability of an already generated action potential to reach the end of the axon and cause synaptic activity. So the oligodendrocytes' effect is sort of like plugging holes in a leaking pipe, whereas the effect of alcohol is more like decreasing the chance that water will actually enter the pipe in the first place. Which is to say: alcohol's work is already done before the myelination comes into play, so increasing the latter won't much affect the former. (IAA neuroscientist, but admitedly this isn't my area of expertise so I may be slightly wrong).
"But Genentech does not want to license the drug for this use as it is. No sir, they will only sell a 'repackaged' version for 100X the original price. A real 'eye opener'."
Actually, that's not really it at all, but thanks for playing. Avastin has been used by retinal specialists to treat wet macular degeneration (and presumed ocular hisoplasmosis syndrome, but that affects far fewer people so there aren't any real studies done with it as yet.) When retinal specialists got the idea to use an angiogenesis inhibitor to treat MD, the real problem was the size of the Avastin molecule. They were concerned that it was too large to penetrate the retinal membrane and thus wouldn't be effective against MD. Genentech immediately went back to the drawing board and developed Lucentis which is a smaller molecule that can more easily penetrate the retinal membrane.
In the meantime, retinal specialists have been using Avastin with some success, but it's believed that Lucentis will be more successful because of the smaller molecule size. Genentech doesn't license the drug for a purpose, the FDA approves it for a purpose. The fact is that there have been no large scale trials with Avastin. The largest I know of is this one by Avery et.al. which had only 79 participants. But now that Lucentis is out, there are official trials being done with it and assuming it passes (which it appears all but certain that it will), it will probably be significantly better at treating MD than Avastin.
The parent is quite correct; but to clarify for those who *aren't* neuroscientists (and clear up a potential misunderstanding from TFA):
Myelin is rather like the insulation on a normal household electric cable. It doesn't actually carry the current, but stops the currrent from grounding out before it gets to its destination. So, to translate (and my apologies to the parent for any loss in translation):
"Myelination from oligodendrocytes just increases the ability of an already generated action potential to reach the end of the axon and cause synaptic activity"
Translation: Myelin sheaths just insulate the nerve signal from the surrounding tissue.
"the effect of alcohol is more like decreasing the chance that water will actually enter the pipe in the first place"
Translation: The effect of alcohol is more like making a dodgy connection at the wall socket.
Disclaimer: IANA neuroscientist (But IAA biochemist).