Spinal Confusion

...an attempt to clarify confusing and innacurate information in science articles

Friday, April 28, 2006

Novel stem cell technology leads to better spinal cord repair

The University of Rochester and Baylor University recently published a paper on a new approach to treating paralysis. They tested three sets of rats: untreated rats acted as controls, while the experimental groups consisted of those receiving transplants of undifferentiated embryonic stem cells or an embryonic derivative, named GDAs.

In order to prove beneficial, either of the two experimental groups had to show some improvement over the control group. The rats treated with undifferentiated embryonic stem cells showed no improvements, but those receiving GDA transplants demonstrated substantial recovery.

What are GDAs, you ask? Researchers start with embryonic stem cells and encourage them to differentiate into a cell type known as glial-restricted precursors, or GRPs. These GRPs are further differentiated into glial-restricted precursor derived astrocytes (GDAs), or GDAs.

Now, hopefully you'll be reading this and cringe at the use of embryonic stem cells (after all, I write this blog for people who oppose their use), but that's not really so important.

GRPs can be obtained from adult stem cells, too. Theoretically, these GDAs should be derivable from adult-derived GRPs.

The adult- and embryo-derived GDAs may share a common gene expression profile, or they may not. If they do, adult-derived GDAs should be as functional as their embryonic counterparts. If not, a differential analysis will show which genes are not common and allow researchers to pinpoint the genes that need to be expressed (or, conversely, repressed) to grant the adult-derived cells the power of the embryonic-derived GDAs.

More interestingly, if the effects are mediated by a select protein or two (remember: genes code for proteins), researchers can work on developing synthesized versions of these proteins and use these to mimic the effects, doing away with cells (adult or embryonic) entirely.

Isn't science wonderful?

Thursday, April 06, 2006

Safety or "Gimme!"?

A new story is out about a woman who lost her sight receiving a chip implant and regaining the ability to "see," if only in a crude manner. The article mentions that the surgery was performed in Portugal, with the final paragraph mentioning "[t]he surgery is not yet performed in the United States" due to some minor, seemingly unimportant issues.

A small thing called "safety" appears to be the primary concern. The neurosurgeon performing the surgery works in the US, but has no clinical trial registered at the national clinical trial database about this procedure.

This raises an interesting pair of questions: Should doctors who officially work in the US be legally allowed to ferry patients (who can come up with the exorbitant fee) to remote locations to perform untested, unproven therapies for them? If so, would it not be better to just allow them to take place inside the United States?

My gut says no, but what would happen if it was allowed? Let's play with the assumption that it was perfectly cool to do just that. What could happen?

For fun, let's narrow this allowance to only those suffering from untreatable diseases, disorders, and injuries to undergo proposed embryonic stem cell-based therapies. Everyone who reads the media knows *ahem* that ESCs can cure everything short of death itself. (This last point, it should be noted, is disputed. The former is too, but not quite as often.)

Editorializing over, back to the point.

The modern Hippocratic Oath no longer includes a provision to "do no harm," so let's say the FDA makes the above allowance.

A random physician, we'll call him Dr. Redar, sets up shop in the US and begins offering ESC-based therapies to help those suffering from paralysis. Dr. Redar is inundated with requests from wealthy individuals who want to be first. Rummaging through the submitted MRIs and medical history of these people, he stumbles upon a recently injured quadriplegic whose MRIs show a high degree of compression.

"Decompression will help this guy out, regardless of whether the ESCs do," the kind doctor says. "My first surgery needs to show impressive results to grab others' interest, so this guy looks like the perfect marketing device!"

The surgery, including decompression, is performed and the patient improves as Dr. Redar anticipated. The results are trumpeted throughout the media, bringing Redar more clients than he could have hoped for. Three months later, he has treated 35patients and only two more have demonstrated any significant improvements.

One of the patients decides she was scammed and decides to take Redar to court, but no lawyer will take her case. "Remember that release of liability form you signed? There was a clause in there stating you understood that, due to a lack of credible prior human studies, the therapy does not carry with it any promises."

Three months more pass and there's an uh-oh: a patient dies as a result of... well, the doctor really doesn't know. The lack of regulation allowed the doctor to move forward without maintaining strict, complete documentation of each client.

The media grabs this story and runs with it. "ESC-based therapy kills patient" is the headline on most major news outlets for an extended period of time. Similar to the Jesse Gelsinger situation, private entitites would shy away from funding research into this young field, further delaying any benefit ESC-based therapies may one day bring to patients.


An attempt to help could backfire in such a devastating disaster. Granted, death is an extreme example and is possible with any procedure -- proven or not -- but the risk of damaging the field is too great.

Another problem would be that, even if the treatment worked, the uncontrolled environment it was produced under would not allow insurances to cover it for others. This would prevent widespread adoption of the treatment, adding further delays for patients in need.

All-in-all, it's a bad deal. As Robin Williams said in Aladdin, "it's not a pretty picture. I don't like doing it!"

Personally, I'll wait for structured trials that have defined safety protocols. Losing what ability I have to breathe independently would truly suck.