20190702

Tue Jul 2 09:08:17 EDT 2019 Slept from ten to six. Woke briefly around one. High of ninety-two and thunderstorms today. Work: - Order monitor and printer for Central Done. - Finish planning Everest hardware purchase Done. - Compile prop mgmt questions Done. - Work on leasing desktop Ansible playbook No. Twenty-minute walk at lunch. Hot. Saw numerous dragon flies — maybe a dozen — all zooming around. Home: - Phone in prescription refill Done. - Play with D&D adventure design A bit. https://news.ycombinator.com/item?id=20337868 http://worrydream.com/ https://www.nytimes.com/2019/07/02/magazine/dead-pig-brains-reanimation.html > In the course of his research, Sestan, an expert in developmental neurobiology, regularly ordered slices of animal and human brain tissue from various brain banks, which shipped the specimens to Yale in coolers full of ice. Sometimes the tissue arrived within three or four hours of the donor’s death. Sometimes it took more than a day. Still, Sestan and his team were able to culture, or grow, active cells from that tissue — tissue that was, for all practical purposes, entirely dead. In the right circumstances, they could actually keep the cells alive for several weeks at a stretch. > If you could restore activity to individual post-mortem brain cells, he reasoned to himself, what was to stop you from restoring activity to entire slices of post-mortem brain? > Through the spring of 2014, the scientists, often laboring in time they stole from other projects, managed to develop a customized fluid that could preserve centimeter-thick chunks of mouse, pig and human brain for long periods. “Six days was our record,” Sestan recalled. “Six days, and the cells were still culturable.” But there was a hitch: The tissue stayed intact only when the samples were stored in a fridge. Once they were removed and brought to room temperature (any accurate modeling of neuronal function would have to occur at 98.6 degrees Fahrenheit), decomposition rapidly set in. > One afternoon, he dropped by Yale’s pathology department to discuss an unrelated issue with a colleague, Art Belanger, the manager of the university’s morgue at the time. “I look over, and there’s this human brain in a sink, mounted upside-down,” Sestan recalled. As he watched, preservative from a nearby plastic bottle dripped through a few lines of tubing and into the organ’s arteries. The rig, a so-called gravity feed, was being used to “fix” the brain, Belanger explained — to preserve it for further study. Sestan nodded. In his lab, he frequently fixed organs, usually by freezing the specimens or immersing them in formaldehyde. “Trust me,” Belanger told Sestan. “Perfusion is much more effective.” > In contrast to immersion, perfusion leverages the existing vascular network — it mimics the flow of blood through the organ. The resulting fixation is more uniform and drastically faster than traditional methods. And if it’s done quickly enough post-mortem, it can prevent cellular decomposition. “You don’t see any breakdown of tissue; you don’t see any bacterial growth,” Belanger told me recently. “Everything just sort of gets put on pause.” > Sestan stopped in front of the gravity feed, eyes wide. Maybe, he thought, he had been thinking about the problem in the wrong way. Maybe the solution didn’t lie in slices of brain, but in an entire brain, perfused the way Belanger was perfusing this one, with hemoglobin-rich fluid standing in for a preservative. “It was my light-bulb moment,” he said. (Belanger told me: “For 30 years, I’d waited to see a scientist go screaming down the hallway, screaming, ‘Eureka!’ That was the moment. Finally.”) But soon enough, Sestan’s euphoria was followed by a dawning awareness of where the experiment might take him. If the path to cellular restoration really did lie in the perfusion of a whole brain, his experiment would be entering entirely unexplored territory. “It’s kind of amazing, considering everything that came later, but that was the origin,” Sestan told me. “We didn’t want to restart life, you know?” > Still, as Sestan acknowledged to me, the project was an outlier for him. He felt compelled to put certain safeguards in place: He added “blockers” to the perfusate, to prevent the rise of electrical activity should the experiment succeed in restoring the neurons to do anything resembling consciousness; later, for the same reason, he began keeping a syringe full of a powerful anesthetic in his lab. > Sestan did acknowledge that, yes, theoretically there is nothing stopping a scientist from immediately building a perfusion machine that could support a human brain. The BrainEx technology is open-source, and pig and homo sapiens brains have a fair amount in common. And there are plenty of conceivable applications for a human-optimized BrainEx. > Consider, Greely suggested, the case of the Italian neurosurgeon Sergio Canavero and his associate, the Chinese scientist Xiaoping Ren, who claim to have transplanted a head from one cadaver to another. Undoubtedly, a scientist with fewer scruples than Sestan, fewer moral qualms about human experimentation, will emerge. “Somebody will perfuse a dead human brain, and I think it will be in an unconventional setting, not necessarily in a pure research manner,” Greely told me. “It will be somebody with a lot of money, and he’ll find a scientist willing to do it.” > In 2016, Sestan employed a machine known as a BIS, or a bispectral index monitor, which is used in hospitals to measure how deeply a patient is “under” during surgery. BIS results are categorized on a scale from zero to 100: Zero is the absence of electrical activity — a chunk of wood would score a zero on the bispectral index — while 90 to 100 is consistent with full cerebral function in a living human. (A person between 40 and 60, target numbers for general anesthesia, will be unresponsive to most stimuli.) > That summer, Sestan was preparing a grant application when Vrselja and Daniele summoned him to the perfusion room. The BIS readout had just hit 10 — at the low end of what is called burst suppression, a stuttering pattern often observed in human patients in a deep coma. “That level, it’s not associated with any kind of cognition,” Daniele told me. “The brain is considered to be entirely inactive. Dead.” > And yet as low as the score was, it wasn’t zero. “I just thought, Yeah, O.K., forget it,” Sestan recalled. “I’m not taking any chances. I said: ‘Unplug the machine. Stop the experiment until we can figure out what’s happening.’ ” That same day, he wrote two emails. The first was to a contact at the National Institutes of Health. The second was to Stephen Latham, the director of the Yale Interdisciplinary Center for Bioethics. > Sestan did acknowledge that, yes, theoretically there is nothing stopping a scientist from immediately building a perfusion machine that could support a human brain. The BrainEx technology is open-source, and pig and homo sapiens brains have a fair amount in common. > Consider, Greely suggested, the case of the Italian neurosurgeon Sergio Canavero and his associate, the Chinese scientist Xiaoping Ren, who claim to have transplanted a head from one cadaver to another. Undoubtedly, a scientist with fewer scruples than Sestan, fewer moral qualms about human experimentation, will emerge. “Somebody will perfuse a dead human brain, and I think it will be in an unconventional setting, not necessarily in a pure research manner,” Greely told me. “It will be somebody with a lot of money, and he’ll find a scientist willing to do it.” https://news.ycombinator.com/item?id=20337716 Interesting, brilliant, and deeply horrifying. Watched some anime. A loud summer thunderstorm in the evening, brought brief respite from the heat. Servings: grains 3/6, fruit 2/4, vegetables 4/4, dairy 2/2, meat 3/3, nuts 0/0.5 Brunch: celery, banana, yogurt, coffee Lunch: migas, Mandarin, avocado Afternoon snack: coffee Dinner: hamburger, fries 109/55

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