Coming of Age: Volume 1: Eternal Life by Thomas T. Thomas Page B

groups—”
    “—and negative Rh factor, which is even more limiting—”
    “—for O, it occurs in about seven percent of the population—”
    “—and for B … well, occurrence is less than two percent.”
    “In other words,” Praxis summed up, “I’m screwed.”
    “Let’s say the match will be difficult and take longer.”
    Praxis pointed to the machinery under the bed. “And what’s the warranty on this thing?”
    “People waiting for transplants have lived for hundreds of days with totally artificial hearts,” Peterson said.
    “But today we want to present you with an alternative,” Jamison concluded.
    He introduced the two strangers in the room as doctors Anderson and Adamson, colleagues from the Stanford Medical Center who specialized in the new field of cellular regeneration.
    “It’s all about taking stem cells from your own body,” Anderson explained. “We isolate them from skin and nerve tissues, muscle and connective tissues. We culture the stem cells in vitro and induce them to grow new organs to specification.”
    “With such an organ,” Adamson put it, “there’s no need for the waiting, searching, and tissue typing, because the implanted material originated in your own body and has all the right antigen signatures.”
    “And also no need for a regimen of immune-suppressing medications,” Anderson concluded. “We don’t interfere with the body’s defense system. That’s one of the major benefits of autonomous regeneration.”
    “You’re going to grow me a heart?” Praxis said. “I didn’t know that was possible.”
    “Well, it’s still in the experimental stage,” Jamison said. “Technically, you would be participating in a clinical trial.”
    “The procedure would not be covered by your insurance,” Peterson said. “And while there’s a modest stipend connected with the trials, we figured in your case—”
    “Screw the money?” Praxis suggested cheerfully.
    “Well, something like that,” Peterson said.
    “So, tell me what’s going to happen.”
    “In the early stages,” Anderson said, “we started with a heart donated from a cadaver. We washed it with various enzymes and detergents to remove the previous owner’s cells, leaving just the connective tissues—a set of intracellular proteins called collagens. This is simply the shape and structure of a human heart but totally inert.”
    “I’ll bet,” Praxis said.
    “We would then bathe this ‘empty’ heart in a solution of stem cells, hormones, chemicals to control cell development, and nutritive media. We place it inside a chamber that provides the appropriate conditions for growth—temperature, pressure, oxygen supply, carbon dioxide removal, et cetera. And the cells arrange themselves and grow into new, living tissue of the appropriate type.”
    “We used to think,” Adamson put in, “that it would be difficult to organize the different kinds of stem cells—muscle, artery, nerve—on such a scaffold and train them to grow into productive tissues. But the amazing thing is that the stem cells seem to be self-organizing, sending chemical signals into their immediate environment and calling forth the right kinds of tissue. It’s the same process that occurs in the womb during—”
    Praxis cut him short. “But you’re still going to put a dead man’s heart inside me?”
    “Not exactly,” Anderson said. “We were able to use the cadaverous hearts in experiments with baboons. But there were still issues of contamination—lingering traces of antigens, virus particles, and such. We actually found it easier to map out the heart’s internal structure, model it on a computer, and then ‘print’ it in three dimensions using layers of fresh, uncontaminated collagen that has been grown synthetically. We can also scale the organ’s size for the intended recipient. You will be getting a new heart made from your own cells that are grown on such an armature.”
    “How long?” Praxis