时差N小时 帮助治疗白血病的干细胞

Yael: Hey, Don, name three types of stem cells in your body?

雅艾尔：嘿，唐，你能说出你体内三种干细胞的名称吗?

Don: I've thought stem cells were from Embryos¹, Yael, do adult have them, too?

唐：我一直以为干细胞来自于胚胎，雅艾尔，成人体内也有吗？

Yael: We've got a few kinds of stem cells, each with a different role. The term “potency” is used to describe the capacity of cells to change, or differentiate², into different cell types when they divide. There are totipotent, pluripotent, multipotent, oligopotent and unipotent cells.

雅艾尔：我们体内有一些不同种类的干细胞，每种都有不同的作用。“效能”这个术语是用来描述细胞分裂时，分化成为不同类型细胞的能力。按“功效”可分为全能性干细胞、多能性干细胞、专能性干细胞和单能性干细胞。

Don: Wow! How about some examples?

唐：哇！能举些例子么？

Yael: Sure, a fertilized³ egg cell as it divides makes every kind of cell in the human body. That one cell can create an entire person. So a fertilized egg is an example of totipotency. Embryonic⁴ stem cells are almost as flexible. They can differentiate into almost any cell type, like lung, muscle, liver, skin or brain cells. But a single embryonic stem cell can never grow into an entire organism. This is an example of pluripotency.

雅艾尔：当然，人体内的一个受精卵细胞在分裂的时候会产生很多种不同的细胞。一个细胞创造了完整的人体。所以受精卵就是一种全能性干细胞。胚胎干细胞与之同样灵活。胚胎干细胞能够分化成几乎所有的细胞类型，像肺、肌肉、肝脏、皮肤或者脑细胞。但一个胚胎干细胞不能长成一个完整的器官。因此它是多能性干细胞的一个例子。

Don: My friend had a Stem Cell Transplants as a treatment for leukemia. What kind of stem cells of those?

唐：我的朋友在治疗白血病的时候接受了干细胞移植，这又是哪一种干细胞呢？

Yael: She probably received a donation of blood stem cells, like those found in bone marrow⁵. Blood stem cells are multipotent. They can make all the different blood cell types, like red and white blood cells or platelets. But they can't create other kinds of cells. An example of oligopotency lurks⁶ in your lymph nodes. Lymphoid stem cells can produce a few, but not all, kinds of blood cells. Finally, cells that only produce identical copies of themselves are called unipotent. Like skin cells, when they divide, they only make more skin cells.

雅艾尔：她可能接受的是骨髓中的造血干细胞。造血干细胞是多能性干细胞，它们可以生产各种类型的血细胞，例如红细胞、白细胞或者血小板。但是不能生产其他种类的细胞。专能性干细胞的一个例子潜伏在你的淋巴结里。淋巴干细胞能制造一些、但非全部的血细胞。最后，只能复制自己的干细胞被称为单能性干细胞，例如表皮细胞，这些细胞再分裂时只能形成表皮细胞。

1 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

2 differentiate   

vi.(between)区分；vt.区别；使不同

参考例句：

• You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
• He never learned to differentiate between good and evil.他从未学会分辨善恶。

3 Fertilized   

v.施肥( fertilize的过去式和过去分词 )

参考例句：

• The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。
• Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。

4 embryonic   

adj.胚胎的

参考例句：

• It is still in an embryonic stage.它还处于萌芽阶段。
• The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。

5 marrow   

n.骨髓；精华；活力

参考例句：

• It was so cold that he felt frozen to the marrow. 天气太冷了，他感到寒冷刺骨。
• He was tired to the marrow of his bones.他真是累得筋疲力尽了。

6 lurks   

n.潜在，潜伏；（lurk的复数形式）vi.潜伏，埋伏（lurk的第三人称单数形式）

参考例句：

• Behind his cool exterior lurks a reckless and frustrated person. 在冷酷的外表背后，他是一个鲁莽又不得志的人。 来自《简明英汉词典》
• Good fortune lies within Bad, Bad fortune lurks within good. 福兮祸所倚，祸兮福所伏。 来自互联网