The Science Behind Tattooing

Once the social symbol of sailors and jail-hardened individuals, tattoos have surged in popularity among the global youth, with around 40% of adults between the ages of 18 and 29 sporting some ink. Tattoo artists spend years training and a lifetime honing their craft, often specializing in one of many forms of skin-based expression ranging anywhere from portraits to calligraphy to watercolor. Whether you’re a fan of the “I-Love-Mom” classics or elaborate Monet-esque mosaics, the practice of tattooing seems almost magical in nature – and like many other tattoo-lovers out there, you’ve probably found yourself wondering: how in the world do tattoos even work?

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The Ethically Hazy, Scientifically Controversial Potential of Head Transplantation Surgery

The Ethically Hazy, Scientifically Controversial Potential of Head Transplantation Surgery

In a somewhat creepy presentation, Italian neuro-surgeon, Dr Sergio Canavero announced at a TED event in 2015 that he would soon successfully transplant a live human head onto a donor body. While watching the video, I noticed that TED flagged the talk as not conforming to their guidelines and they note that his talk is speculative and ethically questionable. Canavero described how he partnered with Dr Xiaoping Ren of China and Canavero told the South China Morning Post in November of 2017 that, “Western bioethicists needed to stop patronizing the world. Chinese President Xi Jinping wants to restore China to greatness.” Contrarily, in another article published days later, a senior health official in China asserts that this procedure is not legal, will not happen and is a publicity stunt. However, Canavero and Ren have found a Guinea pig (pardon the term) in Valery Spiridonov, who suffers from Werdnig-Hoffman disease, also called Spinal Muscle Atrophy Disorder, is a autosomal recessive neuro-muscular disease that usually results in paralysis. Spiridonov, 31, is wheelchair-bound and reports a very low life quality. He has agreed to the head transplant surgery, no matter the outcome.

Image from:http://www.businessinsider.com/head-transplant-surgeon-frankenstein-2017-7

Why are Head Transplants So Darned Hard?

Head transplantation has been considered impossible for many reasons. The first reason is that severing the spinal cord, and then repairing it almost never works. Past attempts with animals typically ended with a paralyzed monkey, mouse or dog. Dr. Canavero argued that he could minimize damage to the cord by using a super-sharp diamond blade to cut the cord. He also claims that he can reconnect the severed cord using a chemical called polyethylene glycol (PEG) and electrical stimulation. Canavero claims that PEG accelerates spinal regeneration and is calling it a “fusogen.” Canavero has insisted that this technique has worked on animals, but there has yet to be any accepted evidence of his claims in peer-reviewed literature.

Image from: https://www.canihelpyouonline.com/the-worlds-first-successful-head-transplant-surgery/

Keeping the brain alive long enough to connect it to the new body (read: blood source) is also very difficult. The brain will degrade beyond repair in minutes without a blood source. Canavero claims to use a combination of cryogenics and silicone tubing to solve this problem. Again, this is a claim for which little evidence has been presented.

After a transplant surgery, the patient’s immune system will often reject and attack implanted foreign tissue, which is the third major problem for a head transplantation: How does the surgeon keep the donor body’s immune system from rejecting the new head? Transplant patients struggle with this problem even with the most common kinds of transplant surgeries but Canavera says that he has conquered this problem in the same way we battle immune rejection in heart or kidney transplant patients – with a cocktail of immune suppressant drugs.

Is it Ethical to Cut Off a Person’s Head and Sew it on to Another Person’s Body?

Image from: https://motherboard.vice.com/en_us/article/qkv5m3/reasons-to-take-a-human-head-transplant-seriously-these-mice

In the industry of scientific research, the scientific method is the primary way in which research moves from hypothesis to accepted theory. In a situation like Canavero’s research, a responsible researcher would start with a moderately large sample size of small rodents, such as mice. Canavero says he has performed the surgery on mice. It is uncertain whether or not the surgeries were successful, or how one might even define success in this case. He would perform the experimental procedure, document it in a legitimate scientific publication and subject it to peer review. examine the article and determine if the research is acceptable. Once peer review was established, Canavero might move on to larger animals, probably dogs (yes, I know it’s awful, but that’s another article) and repeat the process. After that work had been accepted, he might move on to non-human primates (monkeys). After monkeys, a responsible researcher might then move on to a human cadaver.

When a researcher is writing these articles, they should include excruciatingly detailed descriptions of their methods along with well-documented explanations of the results. Canavero and his colleagues have not done this. The articles he has published mention methods minimally, if at all. He does assert that the work was “successful,” without much of an explanation of what “successful” means in objective terms. Neurologists around the world have expressed a variety of sentiments about his research, from mere skepticism to stern disapproval. There is no legitimate ethics board that would approve this procedure, considering the lack of evidence and the ethical considerations. Dr James Fildes, NHS principal research scientist at the University Hospital of South Manchester’s Transplant Centre, said: “Unless Canavero or Ren provide real evidence that they can perform a head, or more appropriately, a whole-body transplant on a large animal that recovers sufficient function to improve quality of life, this entire project is morally wrong.”

So, Just What are (some of) Those Ethical Quandaries?

Consideration 1 – Dr Canavero has announced in several venues that his plan is to use head transplantation to help those who can pay for it to achieve immortality. He sees a world in which rich people can buy a new, younger, healthier body, thus live forever. The two procedures central to the research are the GEMINI Spinal Cord Fusion protocol and HEAVEN (Head Anastomosis Venture Project). This is an ethical argument that could fill books. Is immortality ethical, or even sustainable? Is it fair that this would be an option for only the very wealthy? It sort of reminds me of Elysium.

Image from: https://www.healththoroughfare.com/science/the-first-head-transplant-in-the-world-might-be-more-than-90-successful/7432
Dr. Canavero and a head. I couldn’t say what he is doing with it.

Consideration 2 – In order to do a head transplant, a corpse with an appropriate body needs to be available. According to Organdonor.gov, 20 people die every day waiting for an organ to become available. At a time when wait list for donated organs are months or even years long, how will we handle the supply/demand problem for whole bodies? Is it realistic to donate an entire body for an iffy procedure when those organs can save as many as 8 people on organ donor waiting lists? If were talking about future immortality and wealthy people can live forever, who donates their body? The poor? Prisoners? Clones? It would take another book to even touch on the cloning ethics problems.

Consideration 3 – What kind of hellish scenario would it be for a live human if the head is rejected by the immune system? Currently, the most commonly transplanted organ is the kidney, though we can transplant hearts, lungs, faces, hands, arteries, penises, uteruses, and many other organs with a high likelihood of success. Tissues without a vascular system, such as tendons, cornea, or skin have a much smaller risk of rejection, according to the US Center for Disease Control (CDC). Despite the low likelihood of rejection, it still happens. A head transplant is vastly more complex than any kind of transplant we do currently. Transplantation of organs are typically followed by years of anti-rejection drugs designed to suppress the immune system. This raises the risk of the patient catching an infection that they can’t fight off. The CDC also reports that there is a risk of the transplanted organ having an undetected infection, such as HIV/AIDS, or Hepatitis.

Imge from: https://www.express.co.uk/news/science/933920/Head-transplant-sergio-canavero-Valery-Spiridonov-Werdnig-Hoffmann-disease
Is this a successful head transplant? These two don’t look so good.

Consideration 4 – Arthur Caplan, a professor of bioethics at New York University’s Langone Medical Center. “biochemical differences between the head and the donor body, the person would probably never be able to regain normal consciousness.  “It’s not like putting a light bulb into a new socket,” Caplan said. “If you move the head and the brain, you are putting it into a new chemical environment with new neurological input. I think it would drive the person crazy before they died.” It makes you wonder, how will all of those other person’s hormones and other chemicals change the new brain?

Consideration 5 – To whom will the new combination-body belong? Does the recovering patient become the head or the body? There will be 2 different sets of DNA at play, one from the head, and one from the body. What about identity? While the newly recovering patient has one person’s head, they have another person’s finger prints. What happens to the body’s property, debt, spouse, children? What about the heads personal and legal belongings and family?

This may seem obvious if you think the center of our consciousness is in our brain, but research shows that may not be the case. Much of our behavior and feelings are influenced by our hormones, gut microbiome, and other factors. The enteric nervous system, located in the lining of the gastrointestinal system, is the largest nerve bundle second to the brain, and for this reason the ENS is sometimes called the “second brain.” 95% of our serotonin is found in the ENS. Serotonin is a neurotransmitter that helps reduce depression and anxiety, referred to commonly as a happiness chemical. We don’t know enough about how consciousness, personality, and our feelings really work. We don’t know enough about the ENS or the human microbiome yet to determine where the seat of consciousness is located.

Image from: http://reillytop10.com/previous-lists/2016-list/head-transplants/

What Do You Think?

In a situation like Spiridonov’s, suffering from Spinal Atrophy Disease, I can see why he might risk death or worse for a chance for a better life. Canavero’s arrogant, self-assured attitude and flashy, circus-like handling of his work would seem to convince a vulnerable person that this procedure was indeed not only possible but inevitable. On the other hand, if a head transplant is possible it represents hope to people with conditions that limit their quality of life. Is it ethical to deny them the procedure because of its Frankenstein-esque qualities?  After all, any new surgery might have seemed pretty morbid and risky at one time. Let us know what you think in the comments!