Stem-cell medicine干细胞医学

Hope over hype希望高过炒作
A science writer analyses the history of stem-cell research
一位科普作家分析了干细胞的研究史
Jul 7th 2011 | from the print edition

The Stem Cell Hope. By Alice Park. Hudson Street Press; 318 pages; $25.95.
《干细胞的希望》 爱丽丝•帕克著；哈德逊街出版社；318页；25.95美元

The trouble stems from here
麻烦的干细胞源于这里

THE unrelenting pace of scientific accomplishment often outstrips the progress of moral thought, leaving people struggling to make sense, initially at least, of whether heart transplants are ethical or test-tube babies desirable. Over the past three decades scientists have begun to investigate a branch of medicine that offers astonishing promise—the ability to repair the human body and even grow new organs—but which destroys early-stage embryos to do so. In “The Stem Cell Hope” Alice Park, a science writer at Time magazine, chronicles the scientific, political, ethical and personal struggles of those involved in the work.

科学成就不屈不挠的步伐经常越过道德思想的进步，至少最初让人挣扎在取义之上：心脏移植手术是否符合伦理道德，或者试管婴儿是否值得向往。过去三十年来，科学家们已经开始研究一个医学分支，该分支提供了惊人的希望（能够修复人体，甚至长出新器官），但是这个分支做到这点要破坏早期胚胎。在《时代》杂志的科普作家爱丽丝•帕克所写的《干细胞的希望》中，记载了那些参与这项工作的人在科学、政治、伦理和个人方面的斗争。

Embryonic stem cells are pluripotent: they have the ability to change into any one of the 200-odd types of cell that compose the human body; but they can do so only at a very early stage. Once the bundle has reached more than about 150 cells, they start to specialise. Research into repairing severed spinal cords or growing new hearts has thus needed a supply of stem cells that come from entities that, given a more favourable environment, could instead grow into a baby.

胚胎干细胞是多能的干细胞：它们有能力转变为构成人体的200多种类型细胞中的任何一种；但它们只能在非常早期的阶段做到这点。一旦分裂的细胞束已达到大约150个细胞以上，它们就开始专门分化成一种类型的细胞了。因此，修复断开的脊髓或长出新的心脏的研究需要提供来自实体的干细胞，假如赋予这个实体更加有利的环境，那么它可以成长为一名婴儿。

Immediately after the announcement of the birth of Dolly the sheep—the clone of an adult ewe whose mammary cells Ian Wilmut had tricked into behaving like a developing embryo—American scientists were hauled before the nation’s politicians who were uneasy at the implication that people might also be cloned. Concern at the speed of scientific progress had previously stalled publicly funded research into contentious topics, for example, into in vitro fertilisation. But it did not stop the work from taking place: instead the IVF industry blossomed in the private sector, funded by couples desperate for a baby and investors who had spotted a lucrative new market.

伊恩•威尔莫特将一个成年母羊的乳腺细胞诱发成就象一个发育中的胚胎克隆了多莉羊。在宣布多莉羊诞生后不久，美国科学家纷纷转向这项研究，之后美国政要才对其中人也能克隆的含义感到不安。此前，对科学进步速度的关注让政府资助的研究不涉入有争议的课题，例如，体外授精。但这并没有停止这项工作的开展：取而代之的是试管婴儿行业在私营部门蓬勃发展，而私营部门由求子若渴的夫妇和发现了利润丰厚的新市场的投资者资助。

That is also what happened with human stem cells. After a protracted struggle over whether to ban research outright—which pitted Nancy Reagan, whose husband suffered from Alzheimer’s disease, against a father who asked George Bush’s advisers, “Which one of my children would you kill?”—Mr Bush blocked the use of government money to fund research on any new human embryonic stem-cell cultures. But research did not halt completely: Geron, a biopharmaceuticals company based in Menlo Park, California, had started “to mop up this orphaned innovation”, as Ms Park puts it, by recruiting researchers whose work brought them into conflict with the funding restrictions.

这也是人类干细胞的经历。在是否完全禁止研究的问题上进行了长期争论，南希•里根的丈夫患上了阿尔茨海默氏症，一位父亲问乔治•布什的顾问：“你要杀死我哪个孩子？”，南希杠上了这位父亲，之后布什禁止使用政府的金钱来资助任何新的人类胚胎干细胞培养的研究。但这项研究并没有完全终止：杰龙是一家总部设在美国加利福尼亚州门洛帕克的生物制药公司，正如帕克所说，杰龙的外聘研究人员已经开始“为这项孤儿般的创新做扫尾工作了”，这些研究人员的工作与资金限制有冲突。

Meanwhile, in South Korea a maverick scientist claimed not only to have cloned human embryos but also to have created patient-specific cultures that could, in theory, be used to patch up brain damage or grow a kidney. Alas, he was wrong. But a Japanese scientist did manage to persuade adult skin cells to act like stem cells. If it proves possible to scale up his techniques, that would remove the source of the controversy over stem-cell research.

同时，在韩国一个特立独行的科学家声称，不仅克隆了人类胚胎，而且也制成了特定病人的培养体，从理论上讲，该培养体可以用来修补脑损伤或长出肾脏。可叹的是，他错了。但日本科学家的确设法让成人的皮肤细胞起到干细胞一样的作用。如果证明他的技术可能上规模，将消除对干细胞研究的争论来源。

Three months after he took office, Barack Obama lifted restrictions on federal funding for research on new stem-cell cultures, saying that he thought sound science and moral values were consistent with one another. But progress has been slow: the first human trials in America, involving two people with spinal-cord injuries who have been injected with stem cells developed by Geron, are only just under way. The sick children who first inspired scientists to conduct research into stem cells in order to develop treatments that might help them are now young adults. As Ms Park notes, the fight over stem-cell research is not over, and those who might benefit from stem-cell medicine remain in need.

奥巴马上台三个月后，解除了对联邦资助新干细胞培养研究的限制。奥巴马说，他认为健全的科学和道德观彼此一致。但这方面的研究进展一直缓慢：在美国首次人体试验只是还在进行，有两个脊髓损伤的病人注射了杰龙开发的干细胞。最初促使科学家进行干细胞研究，以开发出可能对他们有所帮助的治疗方法的患病儿童现在已是青壮年。正如帕克指出的，对干细胞研究的战争没有结束，那些可能受益于干细胞药物的人仍然病魔缠身。