What are stem cells? - Craig A. Kohn

什么是干细胞? - 克雷格•科恩（Craig A. Kohn）

翻译人员: Yolanda Zhang 校对人员: Qingqing Mao

Imagine two people are listening to music.

想象一下有2个人在听音乐。

What are the odds

他们在听

that they are listening

同样一个播放列表

to the exact same playlist?

的几率有多大？

Probably pretty low.

很可能非常低。

After all, everyone has very different tastes in music.

毕竟每个人对音乐的喜好都不同。

Now, what are the odds

那么，你的身体

that your body will need

需要与另一个人

the exact same medical care and treatment

完全相同的医学治疗和处理

as another person's body?

的几率又有多大呢？

Even lower.

那就更低了。

As we go through our lives,

在我们的一生当中，

each of us will have very different needs

每个人在自己的医疗方面

for our own healthcare.

都有截然不同的需求。

Scientists and doctors are constantly researching ways

科学家和医生都在坚持不懈的寻找

to make medicine more personalized.

让医疗变得更有针对性的个性化方法。

One way they are doing this

其中一个方法就是

is by researching stem cells.

研究干细胞。

Stem cells are cells that are undifferentiated,

干细胞是未分化的细胞，

meaning they do not have a specific job or function.

也就是说它们还不具有某种特异作用或功能。

While skin cells protect your body,

表皮细胞可以保护我们的身体，

muscle cells contract,

肌细胞可以伸缩，

and nerve cells send signals,

神经细胞可以传递信号，

stem cells do not have any specific structures or functions.

而干细胞没有任何特异性的结构或者功能。

Stem cells do have the potential

但是干细胞具有成为体内

to become all other kinds of cells in your body.

所有其他细胞的潜力。

Your body uses stem cells

我们的身体利用干细胞

to replace worn-out cells when they die.

来取代无法正常发挥功能的死细胞。

For example, you completely replace

比方说，人体每4天就会

the lining of your intestines every four days.

更新一次肠壁细胞。

Stem cells beneath the lining of your intestines

肠壁下部的干细胞

replace these cells as they wear out.

会取代这些老化的细胞。

Scientists hope that stem cells could be used

科学家们希望可以用干细胞来

to create a very special kind of personalized medicine

创建一种非常特别的个性化医疗手段，

in which we could replace your own body parts with,

用我们自身的一部分，

well, your own body parts.

嗯，来代替身体的另一部分，自给自足。

Stem cell researchers are working hard

干细胞研究人员竭力想要找到一种方法，

to find ways in which to use stem cells

可以利用干细胞来

to create new tissue

培育新的组织，

to replace the parts of organs

代替器官中

that are damaged by injury or disease.

由于受伤或者疾病而受损的的部分。

Using stem cells to replace damaged bodily tissue

利用干细胞取代受损的人体组织的方法

is called regenerative medicine.

叫做再生医学。

For example, scientists currently use stem cells

比方说，现在科学家们正在利用干细胞

to treat patients with blood diseases

对患有血液疾病，

such as leukemia.

例如白血病的病人进行治疗。

Leukemia is a form of cancer

白血病是癌症的一种，

that affects your bone marrow.

可以影响骨髓的正常功能。

Bone marrow is the spongy tissue inside your bones

骨髓是骨头内部制造血细胞的

where your blood cells are created.

海绵状组织。

In leukemia, some of the cells inside your bone marrow

当患有白血病时，一部分骨髓内的细胞

grow uncontrollably, crowding out the healthy stem cells

开始不受控地生长，把生成血细胞的

that form your blood cells.

健康干细胞排挤出去。

Some leukemia patients can receive

一些白血病患者可以接受

a stem cell transplant.

干细胞移植。

These new stem cells will create

这些新的干细胞能够制造

the blood cells needed by the patient's body.

病人身体所需的血细胞。

There are actually multiple kinds

有很多种不同的干细胞

of stem cells that scientists can use

都可以被科学家用来

for medical treatments and research.

进行医疗和研究。

Adult stem cells or tissue-specific stem cells

人体大部分的组织中

are found in small numbers

都可以找到少量

in most of your body's tissues.

成体干细胞或者组织特异性干细胞。

Tissue-specific stem cells replace

组织特异性干细胞能够取代

the existing cells in your organs

器官中现有的

as they wear out and die.

老化或死亡的细胞。

Embryonic stem cells are created

胚胎干细胞可以从多余的胚胎细胞中获得，

from leftover embryos that are willingly donated

这些胚胎细胞是由生育诊所里

by patients from fertility clinics.

一些愿意捐赠的患者那里获得的。

Unlike tissue-specific stem cells,

与组织特异性干细胞不同，

embryonic stem cells are pluripotent.

胚胎干细胞有很多种功能。

This means that they can be grown

这就是说它们可以生长为

into any kind of tissue in the body.

身体中任何种类的组织。

A third kind of stem cells

第三种干细胞

is called induced pluripotent stem cells.

叫做诱导多功能干细胞。

These are regular skin, fat, liver, or other cells

这些细胞可以是普通的表皮、脂肪、 肝或者其他种类的细胞，

that scientists have changed

而科学家们已经能够将它们

to behave like embryonic stem cells.

转变为具有胚胎干细胞功能的细胞。

Like embryonic stem cells,

类似于胚胎干细胞，

they, too, can become any kind of cell in the body.

它们也能够成为身体里任何种类的细胞。

While scientists and doctors hope to use

科学家和医生们希望能够

all of these kinds of stem cells

利用所有这些种类的干细胞

to create new tissue to heal your body,

来制造新的组织，帮助身体创伤的愈合，

they can also use stem cells

同时他们也可以利用干细胞

to help understand how the body works.

来了解人体的工作原理。

Scientists can watch stem cells develop

科学家们还可以通过控制和调节来

into tissue to understand the mechnanisms

观察干细胞生成为组织的过程，

that the body uses to create new tissue

从而了解人体制造

in a controlled and regulated way.

新鲜组织的机理。

Scientists hope that with more research,

科学家们希望通过更多的研究，

they can not only develop specialized medicine

不但能够研发针对不同个体情况的

that is specific to your body

特异性药物，

but also better understand

而且能够更好地了解

how your body functions,

人体在

健康和非健康状态下

both when it's healthy

and when it's not.

是如何工作的。