and they're talking about some new medical technology,

看到許多人在談論關於一些新興的醫學科技技術

Some breakthrough treating congestive heart failure or regrowing muscle tissue in wounded soldiers.

一些在治療堵塞性心臟衰竭或者在受傷士兵身上重新長出肌肉組織等

I bet you that that story is going to mention that this new type of therapy uses stem cells.

我打賭你一定看過他們提過這種使用幹細胞的新興療法

And I bet you, like most people, are going to listen along and just go [nods agreeably]

而且我打賭，你跟大多數人一樣會越聽越疑惑像是這樣（疑惑點頭狀）

Without actually knowing what stem cells are, because who has time to know what stem cells are?!?

我們其實對幹細胞一點都不認識，因為誰有時間去了解幹細胞是什麼阿？！

Today, we are making time.

今天，我們要擠出時間

You have lots of different types of cells in your body.

你身體裡有許多不同種類的細胞

You've got muscle cells, and skin cells, and liver cells, and brain cells,

有肌肉細胞，皮膚細胞，肝臟細胞以及腦細胞

Most of these cells have to be replaced every once in a while.

大多數的細胞都會在經過一段時間後汰換

Your tastebuds, for instance, are replaced every 10 days or so,

舉例來說，你的味蕾細胞約以10天的週期汰換

Skin cells are replaced every couple of weeks, and liver cells turn over every 300-500 days.

皮膚細胞會在每隔幾週更新，肝臟細胞會在約300至500天汰換更新

The cells that are doing the replacing of the old cells, and the repairing of the damaged tissue are adult stem cells, also called somatic stem cells.

那些執行汰換老細胞，修復損壞組織的是成熟的幹細胞，也被稱為體幹細胞

The different sort of cells, skin cells, liver cells, retina cells, muscle cells and intestine cells,

不同種類細胞如皮膚細胞、肝臟細胞、視網膜細胞、肌肉細胞和腸細胞

They all have very specific jobs and they're built in very specific ways to do those jobs.

都具有非常特殊專門的工作，而且它們是以非常特殊的方法形成以執行那些工作

Different shapes, sizes, contents, mean you can't just stick a muscle cell into a damaged liver an expect it to start breaking down your alcohol for you.

不同的形狀、大小、內部構造，代表你不能夠任意將肌肉細胞放到受損的肝臟細胞附近期待它們開始替你分解酒精

Somatic stem cells, on the other hand haven't decided what the heck they're gonna be.

另一方面，體幹細胞還未特化形成執行特定目的的細胞

They're undifferentiated. They haven't specialized yet.

它們處在一種未定的狀態。還沒特化的狀態下

Like a college freshman, or, let's face it, a recent college graduate. They have no idea what they're going to do with their lives.

就好比大學新鮮人或者，不爭的事實，一個剛畢業的大學生。根本不知道自己未來要做什麼

but just like there are different types of college graduates, there are different types of adult stem cells.

但就像大學畢業生也有不同的類型，成熟幹細胞也是一樣

Some can become more different kinds of things than others.

其中某些細胞能夠成為比其他細胞更為不同的型態

Pluripotent adult stem cells can become many different types of cells all over the body,

萬能成熟幹細胞能夠成為身體各個部位中許多不同種類的細胞

However, they're really hard to track down because there are so few of them in each organ or tissue.

然而，由於它們在各個器官或組織當中數量都相當的少所以很難去追蹤到

There also multi potent adult stem cells which are more common in the body,

也有更為常見的多功能幹細胞在體中

but restricted in the kind of cell they can become

但它們能夠分化成為的細胞種類就相對有限制

it is kinda like the difference between graduating from trade school where you have been trained to do a few different possible jobs

這有點像是你受到商學院訓練後未來有比較多選擇的路以及

and graduating with a degree in philosophy or something

從哲學系畢業的學生就比較少出路一般

equally unprepared for all jobs

或者從那些沒有很多出路的學系畢業一樣

so yeah , stick a Pluripotent cell in a damaged liver

所以是的，我們專心看萬能幹細胞在受損的肝臟中

and it just happily becomes a liver cell

並且看它們愉快地轉變成為一個肝臟細胞

pretty cool

這實在很酷

but there are some even better types of stem cells to be had

但有些更酷的幹細胞

embryonic stem cells

胚胎幹細胞

which are also Pluripotent

也是萬能幹細胞的一種

these are the cells inside a human embryo when it is a blastocyst

這些細胞是在人體胚胎處在胚泡期時

basically just a tiny nugget of human cells four or five days old

基本上就是一團才四、五天大，非常渺小的人體細胞

which is destroyed in the process of removing the stem cells from inside it

也正是幹細胞從裡頭被移除、摧毀的過程

these embryonic cells are obtained from in vitro fertilization clinics

這些胚胎細胞包含了在試管內培養

that fertilize eggs outside of the mother's body for couples who are having trouble conceiving

具有生育困難的夫妻裡，母親體中取出的受精卵

naturally, these clinics have some left over fertilized eggs

也就是自然地會帶有一些體內殘餘的細胞

so with the donor's permission they are given to scientists doing stem cell research

在醫生同意之下能夠給予科學家研究幹細胞的機會

now the main advantage of the embryonic stem cells is that

胚胎幹細胞主要的優點在於

while adult stem cells can be grown in culture for time

當成熟幹細胞在組織培養中成長一段時間後

meaning they can be made to multiply over and over in a nutrient solution

也就是說它們處在一個充滿營養液的環境中不斷地倍數成長

they can't grow as long or as fast as the embryonic stem cells

它們不再像以往是胚胎幹細胞時那樣成長快速

which can be maintained indefinitely into the right conditions

也就是不能無限期地維持在一個對的環境當中

after just six months in culture , a single wad of 30 embryonic stem cells will have yielded millions of stem cells

大約在組織培養六個月後，一個由30個胚胎幹細胞組成的單一小團會釋出百萬個幹細胞

which can go on to develop pretty much into any type of cell in the body

也就是大部分在之後能夠發展成為身體中個種類的細胞

also adult stem cells if used in some sorts of transplant therapies are more likely to be rejected than embryonic stem cells

同樣地成熟幹細胞如過用在某些種類的移植療法中常常會比使用胚胎幹細胞來得容易被排斥

stem cell research is currently pretty hopin

幹細胞的研究目前非常的夯

embryonic stem cells are being used by researchers all over the world

胚胎幹細胞被全世界科學家拿來研究

to figure out how to repair or replace damaged cells and organs and create new drugs

以了解如何修復或者更換受損細胞和器官，製造新藥

but regulations have taken their toll

但是法規嚴格規定使用數量上限

there are only about thirty five stem cell lines or families of identical pluripotent stem cells that are available for federally funded research in America

在美國只有約35條幹細胞生產線或同種類的萬能幹細胞由聯邦政府出資或者可供研究使用

whereas Europe has a couple thousand

歐洲則有約數千條產線

so there , now you never have to " nod along " your way through another news report about stem cells again

所以，你現在絕不會再只是「點頭如搗蒜」般鴨子聽雷地聽完談論幹細胞的新聞了

thanks for watching this episode of SciShow

謝謝你收看這集的SciShow

if you have any questions , comments or suggestions

若有任何問題，在下面評論或建議

you can find us on Facebook and twitter or of course down in the comments below

你可以在臉書或推特上找到我們或者也能在這部影片下留言

and if you wanna keep getting smarter with us here in SciShow

你若想要跟著SciShow一起變得越來越聰明

you can go to youtube.com/SciShow and subscribe

上YouTube.com/SciShow並訂閱我們

transcription by Dr.A

由Dr.A翻譯