Human Nature: Science, Technology, and Life.

Cyborg Seniors

If you get the Human Nature RSS feed but don't check the Slate home page, you may have missed an article worth reading: How seniors became cyborgs. It's about the mechanical and electronic components we've been putting into old people to replace failing body parts. It's part of our "Geezers" issue. Take a look.

Human Liquid

If you've been thinking lately about how to dispose of your corpse—and I know I have—there's good news. You may soon have a new option: being dissolved in lye. Well, let's not call it that. Let's call it "alkaline hydrolysis." According to AP reporter Norma Love (what a byline!), the process leaves a "brownish, syrupy residue":

It uses lye, 300-degree heat and 60 pounds of pressure per square inch to destroy bodies in big stainless-steel cylinders that are similar to pressure cookers. ... In addition to the liquid, the process leaves a dry bone residue similar in appearance and volume to cremated remains. It could be returned to the family in an urn or buried in a cemetery. The coffee-colored liquid has the consistency of motor oil and a strong ammonia smell. But proponents say it is sterile and can, in most cases, be safely poured down the drain, provided the operation has the necessary permits.

I know it sounds bad. Lye is what we use to dissolve dead animals, and. over the years, mass-murdering dictators have given it a bad name, using it to torture people and get rid of bodies. But think of the benefits: "Alkaline hydrolysis doesn't take up as much space in cemeteries as burial. And the process could ease concerns about crematorium emissions, including carbon dioxide as well as mercury from silver dental fillings."

Oh, and in case you're worried about ending up in your grandkids' water supply:

George Carlson, an industrial-waste manager for the New Hampshire Department of Environmental Services, said things the public might find more troubling routinely flow into sewage treatment plants in the U.S. all the time. That includes blood and spillover embalming fluid from funeral homes.

Given the alternatives -- incineration, rotting, being eaten by worms—is it really so bad?

No wonder the life-exit industry is so excited. Funeral Service Insider (yes, that's a real publication) calls it a "game-changing technology." Those funeral directors -- what a riot.

But, wait, there's a problem. Opponents in New Hampshire are trying to ban the practice before a local funeral home starts using it. A spokesman for the local Catholic diocese tells Love: "We believe this process, which enables a portion of human remains to be flushed down a drain, to be undignified."

Undignified?

Hey, I'm all for human dignity. When it comes to hand-wringing about messing with the human body, me and Leon Kass are like this (holds two fingers together). (That's a joke for all you liberals, libertarians, and transhumanists.) But, hey, c'mon. We're not talking about live bodies here. We're talking about dead ones.

Let's be serious. The more we learn and think about biology, sentience, and intelligence, the more we're going to have to rethink the relationship between "human" and "dignity." On the one hand, stem cells and other technologies, such as bio-artificial organs, will force us to ask whether human parts deserve the kind of respect we accord to whole human beings. On the other hand, discoveries about animal intelligence will force us to rethink the sharp line we've drawn between our species and others. Does a dead human deserve more respect than a live pig?

I won't even to try to answer that today. But feel free to go at it yourself.

The Bio-artificial Industry

How do you feel about mass-producing and selling human tissue in machine form? I hope you like the idea. Because it's on the way.

A few days ago, the University of Michigan trumpeted a study validating the efficacy of its "bioartificial kidneys." In a clinical trial involving people with acute renal injury and failure, the kidney boosters cut the usual death rate (compared to patients using conventional "continuous renal replacement therapy") from two in three patients to one in three.

Pretty amazing. But just what is a "bioartificial" kidney? Here's U-M's description:

The bioartificial kidney includes a cartridge that filters the blood as in traditional kidney dialysis. That cartridge is connected to a renal tubule assist device [RAD], which is made of hollow fibers lined with a type of kidney cell called renal proximal tubule cells. These cells are intended to reclaim vital electrolytes, salt, glucose and water, as well as control production of immune system molecules called cytokines, which the body needs to fight infection. Conventional kidney dialysis machines remove these important components of blood plasma, along with toxic waste products, and cannot provide the immune regulation function of living cells. Initial testing in animals ... found the cells in the RAD perform the metabolic and hormonal functions lost in acute renal failure.

This is the point I've made in recent posts about biological pacemakers and limb regeneration. Prosthetics are nice, but flesh is better. That's why the U.S. Army is now funding tissue regeneration. Instead of trying to reengineer everything in biology, we're learning to borrow, cultivate, and replicate it. Let Mother Nature do the work: She already knows how to filter toxins while keeping what your body needs and regulating your systems.

David Humes, the professor behind the U-M study, is also the scientific founder of the company that's preparing to commercialize the RAD. He envisions the new paradigm this way:

[T]he nature of our new approach -- using living cells as therapeutic agents -- argues for the feasibility of developing whole classes of new cell-based and tissue engineered therapies. The ability to harness vital processes of cells, to target their living molecular machinery on restoring critical substances which have become disordered by disease, has vast implications for the future of medicine. The apparently successful use of living cells in this way validates our approach and should encourage others to investigate cell therapies for a range of disorders.

Technologically, this is a sensible and powerful idea. It will save lives. But as an inflection point in our thinking about human flesh, it's, well, pretty RAD. What we're getting into is not just the commercialization but the mass-production of body parts. It's a bit like PETA's campaign to commercialize lab-grown meat -- except that in this case, the meat will be human.

Where do we get the cells in the cartridge from? According to the American Society of Nephrology, they're "grown from donor kidneys." So we're starting with somebody's donated organ. Instead of transplanting it to one person, we're growing cells from it, which can then be farmed out to multiple patients. We're not just distributing the cells; we're incorporating them into what U-M calls a "living cell cartridge." It's bio -- it's artificial -- it's bio-artificial.

Like lab-grown meat, the living tissue in the cartridge may run into spoilage problems. U-M notes that its researchers are still working on the "challenges of mass producing, storing and shipping a living-cell device." But the goal, according to the nephrology society, is definitely "mass production." And the next step will be to repackage it as a "wearable kidney that performs natural functions unachievable through man-made technology alone." Real flesh, grown from somebody else, mass-produced, packaged into a cartridge, and worn on your body. Good luck sorting the bio from the artificial.