July 03, 2013

Internet Reactions to Technical Hurdles overcome for Head Transplants

Recently Nextbigfuture wrote about technical hurdles being overcome for head transplants.

Quick list of the some of the reactions -
* Several have noted that they should really be called body transplants
* Someone tweeted that the top 1% will always get ahead
* The article made the front page of Reddit
* Fark - Giving and getting head just became easier .
* Humorist Dave Barry notes that the Weekly World News Had This Years Ago
* Some writers of fiction like Peter Adams Salomon - At this point I would like to say “Well, I told you so…”
* Various bioethics people are freaking out over the possibility.

One of the Case Western doctor (Dr Jerry Silver) who repaired rat spinal cord damage - “It’s complete fantasy, that you could use [PEG technology] in such a traumatic injury in an adult mammal,” Silver says. “But to severe a head and even contemplate the possibility of gluing axons back properly across the lesion to their neighbors is pure and utter fantasy in my opinion.”

* Qz.com had coverage.

Canavero (who wrote the paper) estimates that the total cost of a head transplant would be at least €10 million euros ($13 million.)

Telegraph UK - Canavero says a team of 100 could perform the operation in 36 hours. Both heads would have to be removed at the same time, and reconnected within an hour.

"This is no longer science fiction. This could be done today — now. If this operation is done it will provide a few people with a substantial amount of extra life,” he said. “The only reason I have not gone further is funding.

Canavero is most known for waking a woman (2008) who was in a vegetative state for two years.

The technical hurdles have now been cleared thanks to cell engineering. As described in a paper, the keystone to successful spinal cord linkage is the possibility to fuse the severed axons in the cord by exploiting the power of membrane fusogens/sealants. Agents exist that can reconstitute the membranes of a cut axon and animal data have accrued since 1999 that restoration of axonal function is possible. One such molecule is poly-ethylene glycol (PEG), a widely used molecule with many applications from industrial manufacturing to medicine, including as an excipient in many pharmaceutical products. Another is chitosan, a polysaccharide used in medicine and other fields.

Surgical Neurological International - HEAVEN: The head anastomosis venture Project outline for the first human head transplantation with spinal linkage (GEMINI)

* In 2000, guinea pigs had spinal cords surgically cut and then protected with PEG chemical (like what is proposed here) and they had over 90% of spinal nerve transmission restored with a lot of mobility and function restored
* a head of a monkey was transplanted in the 1970s but the spinal cord could not be repaired at the time
* Spinal cords have been regrown in rats.

* Effective repair of traumatically injured spinal cord by nanoscale block copolymer micelles (Nature Nanotechnology, 2009) These experiments treated the damage after about ten minutes and were able to get a lot of movement back in most cases. The damage was a crushing of the spinal cord, so the transplant procedure would have better results because it would be a careful separation of the spinal cord under cold conditions with immediate application of the protectant chemicals.

Spinal cord injury results in immediate disruption of neuronal membranes, followed by extensive secondary
neurodegenerative processes. A key approach for repairing injured spinal cord is to seal the damaged membranes at an early stage. Here, we show that axonal membranes injured by compression can be effectively repaired using self-assembled monomethoxy poly(ethylene glycol)-poly(D,L-lactic acid) di-block copolymer micelles. Injured spinal tissue incubated with micelles (60 nm diameter) showed rapid restoration of compound action potential and reduced calcium influx into axons for micelle concentrations much lower than the concentrations of polyethylene glycol, a known sealing agent for early-stage spinal cord injury. Intravenously injected micelles effectively recovered locomotor function and reduced the volume and inflammatory response of the lesion in injured rats, without any adverse effects. Our results show that copolymer micelles can interrupt the spread of primary spinal cord injury damage with minimal toxicity.

Improvement in the locomotor function in the micelle-treated group was evident by a more rapid increase of BBB scores in the first 14 days and continuation of improvement over the following two weeks. Specifically, at 28 days post-injury, the BBB scores were 12.5 + or minus 3.1. From a clinical perspective, an animal with a BBB score equal to or less than 11 lacks hindlimb and forelimb coordination, whereas a score of 12 to 13 corresponds to occasional to frequent forelimb and hindlimb coordination. Reaching a BBB score of 12 is significant in that it is a sign of axonal transduction through the lesion site

Illustration of the monkey head transplant from the 1970s.

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