そうね。
>>
In the year since the papers’ retraction, he and Kojima had tweaked the procedure, making small adjustments to the media and returning to the original chemical stimulus, ATP, which also fuelled the cells, instead of the hydrochloric acid indicated in the publications. For months, they had tried to make a teratoma, the first major step to indicating pluripotency.
(続き)
>>
Now we walked over to Vacanti’s lab to see the results. He wasn’t optimistic. Before my arrival, he told me, he had called an emergency phone meeting with Kojima and his brother Martin. “I said, ‘We have to have something to demonstrate that this is indeed real or we’re going to look really stupid.’ ” As it happened, he said, just a few days before, he had seen the best-looking spheres in many months. They had tested positive for the embryonic-stem-cell markers Oct4 and Nanog, calculated by a machine that is not subject to the vagaries of auto-fluorescence. He had broken the spheres apart and placed the cells in a medium that encouraged the growth of neurons. The new plan was to test them for a protein called nestin, which, he said, would show that a mature skin cell had been transformed into a neural stem cell—taken back down to the root and up another branch.
(続き)
"Compact and taciturn, Kojima looked up and said “Good data” before saying hello. The nestin levels were fifty to sixty times as high as the last time he had checked. “Ha!” Vacanti said, jumping up and down and cheering.
“It’s only one sample,” Kojima said.
“Doesn’t matter,” Vacanti replied cheerfully. “One’s good for me.”
"
(続き)
In the progress of their research, they were all the way back to 2008, before Obokata, but Vacanti still saw a cause for celebration. After calling his brother, he decided that it was time for lunch and a glass of wine; Kojima came along, and Vacanti kept exhorting him to make merry. “I’m excited,” Kojima said. “But I need correct data, otherwise—” He chopped his hand through the air.
(続き)
Vacanti was reluctant to ruin a good day, but eventually he couldn’t put off looking at the teratoma slides any longer. Back in the lab, he sat down at the microscope and examined them for a long time. I stole a glance: a view of pink bubbles and marbled swirls like the endpapers of a seventeenth-century Venetian book. After a while, Vacanti concluded that the cells had failed to form new tissues; the only tissues evident had clearly come from the host mouse. Months of work, without producing evidence of pluripotency. But he didn’t dwell on that troubling thought for long. “Koji, you know what I was thinking?” he said. “We had Oct4, we had Nanog, we had nestin. Let’s never do another test. Let’s let it be someone else’s problem!”
