How far should science go to help the sick and the suffering

　　Jackie: Welcome to BBC Learning English dot com and Insight Plus - a series first broadcast in 2001 that looks at the language of issues you hear about in the news. How far should science go to help the sick and the suffering? Today on Insight Plus, Lyse Doucet looks into the cloning debate.
　　Lyse: Cloning is copying, it can be applied¹ to many things but here we are talking about copy of a living organism. We are all made from billions of cells, and at the centre of each one are the instructions - the blueprint² - for building our bodies which is stored in the form of a chemical called DNA³. There are two types of cloning, reproductive cloning （生殖克隆）where a new baby would be created or therapeutic⁴ cloning（治疗性克隆）, that’s about copying just some of the cells. Therapeutic cloning concentrates on some special cells called stem cells - they’re the powerfully adaptable⁵ 'master cells'. Opinion is deeply divided about whether or not we should develop this technology. The BBC World Service has been reporting the developments made in this most sensitive of issues, we hear first from Dr Robin⁶ Lovell-Badge of Britain's Medical Research Council.
　　ClipThese cells exist naturally in the body and they are there to replace cells that are lost through natural processes, so you lose skin cells all the time, you lose cells from your intestines（肠） - your guts⁷ - and there are stem cells in the brain to replace a few cells which are lost. And normally the stem cells divide just the right amount to maintain the organ in a good state. But in the cases where there's accidental damage（意外损害） or a disease which affects a tissue or an organ, then quite frequently the stem cells aren't able to divide fast enough to replace the damaged tissue. So it's hoped that by growing them in a test tube, if you like, that they can be now used to replace lost cells in a personLyse:  As Dr Robin Lovell-Badge explained, stem cells regenerate⁸（更新） tissue. They repair and maintain our kidneys, liver and other organs. By introducing new stem cells into the body, scientists hope to renew damaged tissue and even fight illnesses such as heart disease and Parkinson's - a disease of the brain.
　　In 1998, American scientists succeeded in isolating⁹ and culturing - growing - stem cells. They unlocked their potential for medical research and treatment. In future stem cells could be a vital tool in the war to keep everyone well and healthy.
　　Doctors know that adult stem cells can develop into different cell types. In Sweden, for example, the neural（神经的） cells - cells taken from the brain of adult mice - have been used to generate kidney, heart and liver cells. But researchers aren’t sure whether adult stem cells are as perfectly¹⁰ adaptable as those found in embryos¹² - newly created lives. When an egg is fertilised（施肥） by a sperm¹³, it forms a ball of cells, any of them can develop into almost any cell in the body. These 'master' cells - embryonic¹⁴ stem cells - are at the centre of much of the current research.
　　Why is the procedure is causing so much anxiety? Well, one way of harvesting - collecting -stem cells is to actually create embryosm, through a process known as therapeutic cloning. It’s based on a technique pioneered at the Roslin Institute in Edinburgh, in 1996, Dolly the sheep was born. Dolly was the first mammal cloned from an adult cell - a nucleus¹⁵ taken from an adult sheep cell and inserted into an empty egg. The egg's development into an embryo¹¹ was triggered by a revolutionary new technique which makes it possible to clone existing animals - and it could be used to produce human clones.
　　Once we have perfect copies of ourselves we’ll be able to repair and renew faulty parts of our body. The transplant techniques we have now sometimes fail - in the US, for example, twelve percent of patients receiving organs from dead donors¹⁷ die within a year of the operation. That’s partly because our bodies work hard to reject anything alien that is grafted¹⁹ （接枝，贪污）onto it - anything that is imported into the body, even if it’s a new lung, a liver or a new heart.  Chronic²⁰ （慢性的）rejection²¹, which usually occurs three or four years after the operation, causes even more deaths. In Britain, heart transplant survival rates fall from 81% in the first year to 65% of patients surviving five years after the operation. Professor Richard Gardner believes therapeutic cloning could solve this problem.
　　ClipAs with all organ transplants, just using the stem cells that were available you would not always have a perfect match and you'd have to treat patients with drugs to stop the graft¹⁸ being rejected. And that is why people are talking about going beyond this. And that would be taking a human egg, putting the nucleus（核） from the patient into that egg and instead of fertilising it, activating²² it to grow just to the stage where you can derive（派生，导出） embryonic stem cells, because they would be genetically²⁴ identical with the patient and you wouldn't have the problem of graft rejection.
　　Lyse: That was Professor Richard Gardner, chairman of Britain’s Royal Society Working Group on Therapeutic Cloning. He has great hopes for medical research in this field. Let’s take for example the case of a male patient who needs a heart transplant. Professor Gardner believes that one day it may be possible to extract the nucleus of a cell from the patient to briefly²⁵ clone an embryo of him and them to use the embryo's stem cells to treat him. So the patient’s body would then accept stem cells which perfectly matched his genetic²³ makeup²⁶ instead of rejecting a transplanted donor¹⁶ organ or a tissue graft. In future cell nuclear transfer could even be used to create a personalised bank of stem cells, they could be stored and used as and when the patient needs them.
　　ClipWhat we're looking for in the future is to get away from the situation where virtually all those requiring a graft have to wait until someone else dies to provide a healthy organ or tissue for them. The stem cells（干细胞） offer the prospect²⁷ of building up banks of cells that you can then grow them and make them become whatever cell type the patient requires.
　　Lyse: But treatments like these remain a distant prospect. When scientists understand and can control the development of stem cells, activating their growth into nerve cells, heart cells or blood cells, will they be able to use them in the treatment of disease.
　　Stem cell research is the subject of today’s Insight Plus from the BBC World Service - it’s your guide to the language and background to the stories that stay in the news. Some of the greatest medical advances of the 21st century may result from（起因于） stem cell research. The development and ethics²⁸ of therapeutic cloning will attract the attention of the world’s media for some time to come.
　　And governments around the world also face the ethical²⁹ dilemmas（道德困境） provoked by this field. Should scientists be allowed to harvest stem cells from embryos? Should the cloning of human embryos be permitted, even if reproductive cloning, the creation and birth of cloned human beings, is outlawed（失去法律保护的）? Very young embryos are now legally used in fertility research in many countries. The unwanted embryos used by some of the American scientists who first cultured stem cells came from fertility clinics. But in the United States public funds cannot be used for any research which involves killing³⁰ embryos.
　　Britain is one of the first countries to consider legislation which would allow therapeutic cloning and stem cell research on embryos up to 14 days old. A committee headed by Professor Liam Donaldson, Britain’s Chief Medical Officer, has spent a year preparing a report on stem cell research for the British Government. It’s a debate that’s being heard around the world.
　　ClipThe conclusions of the committee were that stem cells have an enormous potential to create new forms of treatment for diseases which are currently incurable… major, major medical potential. We need medical research to see if this potential can be realised. The potential benefits in this balancing exercise outweigh³¹ some of the concerns and would be justified³² by the potential benefits for future generations of patients - we are talking about here research at this stage, not treatment.
　　Lyse: The committee say that the benefits outweigh the ethical concerns. They believe research should continue, should go forward, but only if strict rules limit, or regulate, the research. Professor Donaldson would like to see the law tightened³³ to ensure no-one is allowed to create a human being.
　　ClipMost important of all and without room for any ambiguity（不明确的，含糊的） or doubt, that the creation of a human being through cloning should not be permitted under any circumstances and is illegal at the moment and should remain illegal, reinforced by even more legislation.
　　Lyse: Around the world, many who believe that an embryo, however young, is a human life remain deeply concerned by the new research. Dr Sandy Thomas from Britain’s ethics organisation³⁴, the Nuffield Council on Bioethics, explains their concerns.
　　ClipPeople are concerned of course about how we should use embryos, if at all we should use embryos for research. In some countries embryo research of any kind is prohibited. In others, a very limited amount of embryo research is allowed. And the reason that there are ethical concerns here is that obviously an embryo has the potential to become a human being and we therefore should accord it some respect. The problem for many people is how much respect? So much respect that we do no research at all on a one or two day old ball of cells, or for example, respect at some perhaps slightly later line when we would not allow research, perhaps fourteen days, as in the UK.
　　Lyse:Many who oppose embryo research believe scientists should only work with adult stem cells. But scientists argue that even if therapeutic cloning was banned, embryo research would still be needed to help them to understand how stem cells function.
　　Today we've been discussing stem cell research and the ethics of therapeutic cloning. One solution may lie in the pioneering technology used to create Dolly the sheep. In this case, scientists reprogrammed the adult cell used to clone her. The nucleus of the cell was taken to a near embryonic state before it was inserted into an empty egg cell, it was then allowed to develop again as an embryo. One day, scientists may be able to extract and 'reprogram' patient's cells before they re-insert them into the body, there they would begin to regenerate damaged tissue and organs. Such cells would never be implanted into an egg, the creation and destruction of an embryo would be avoided.

(本文由在线英语听力室整理编辑)

1 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

2 blueprint   

n.蓝图，设计图，计划；vt.制成蓝图，计划

参考例句：

• All the machine parts on a blueprint must answer each other.设计图上所有的机器部件都应互相配合。
• The documents contain a blueprint for a nuclear device.文件内附有一张核装置的设计蓝图。

3 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

4 therapeutic   

adj.治疗的，起治疗作用的；对身心健康有益的

参考例句：

• Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
• When I was sad,music had a therapeutic effect.我悲伤的时候，音乐有治疗效力。

5 adaptable   

adj.能适应的，适应性强的，可改编的

参考例句：

• He is an adaptable man and will soon learn the new work.他是个适应性很强的人，很快就将学会这种工作。
• The soil is adaptable to the growth of peanuts.这土壤适宜于花生的生长。

6 robin   

n.知更鸟，红襟鸟

参考例句：

• The robin is the messenger of spring.知更鸟是报春的使者。
• We knew spring was coming as we had seen a robin.我们看见了一只知更鸟，知道春天要到了。

7 guts   

v.狼吞虎咽，贪婪地吃，飞碟游戏（比赛双方每组5人，相距15码，互相掷接飞碟）；毁坏（建筑物等）的内部( gut的第三人称单数 )；取出…的内脏n.勇气( gut的名词复数 )；内脏；消化道的下段；肠

参考例句：

• I'll only cook fish if the guts have been removed. 鱼若已收拾干净，我只需烧一下即可。
• Barbara hasn't got the guts to leave her mother. 巴巴拉没有勇气离开她妈妈。 来自《简明英汉词典》

8 regenerate   

vt.使恢复，使新生；vi.恢复，再生；adj.恢复的

参考例句：

• Their aim is to regenerate British industry.他们的目的是复兴英国的工业。
• Although it is not easy,you have the power to regenerate your life.尽管这不容易，但你有使生活重获新生的能力。

9 isolating   

adj.孤立的，绝缘的v.使隔离( isolate的现在分词 )；将…剔出（以便看清和单独处理）；使（某物质、细胞等）分离；使离析

参考例句：

• Colour filters are not very effective in isolating narrow spectral bands. 一些滤色片不能很有效地分离狭窄的光谱带。 来自辞典例句
• This became known as the streak method for isolating bacteria. 这个方法以后就称为分离细菌的划线法。 来自辞典例句

10 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

11 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

12 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

13 sperm   

n.精子，精液

参考例句：

• Only one sperm fertilises an egg.只有一个精子使卵子受精。
• In human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中，一个精子使一个卵子受精。

14 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。

15 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

16 donor   

n.捐献者；赠送人；(组织、器官等的)供体

参考例句：

• In these cases,the recipient usually takes care of the donor afterwards.在这类情况下，接受捐献者以后通常会照顾捐赠者。
• The Doctor transplanted the donor's heart to Mike's chest cavity.医生将捐赠者的心脏移植进麦克的胸腔。

17 donors   

n.捐赠者( donor的名词复数 )；献血者；捐血者；器官捐献者

参考例句：

• Please email us to be removed from our active list of blood donors. 假如你想把自己的名字从献血联系人名单中删去，请给我们发电子邮件。
• About half this amount comes from individual donors and bequests. 这笔钱大约有一半来自个人捐赠及遗赠。 来自《简明英汉词典》

18 graft   

n.移植，嫁接，艰苦工作，贪污；v.移植，嫁接

参考例句：

• I am having a skin graft on my arm soon.我马上就要接受手臂的皮肤移植手术。
• The minister became rich through graft.这位部长透过贪污受贿致富。

19 grafted   

移植( graft的过去式和过去分词 )； 嫁接； 使（思想、制度等）成为（…的一部份）； 植根

参考例句：

• No art can be grafted with success on another art. 没有哪种艺术能成功地嫁接到另一种艺术上。
• Apples are easily grafted. 苹果树很容易嫁接。

20 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

21 rejection   

n.拒绝，被拒，抛弃，被弃

参考例句：

• He decided not to approach her for fear of rejection.他因怕遭拒绝决定不再去找她。
• The rejection plunged her into the dark depths of despair.遭到拒绝使她陷入了绝望的深渊。

22 activating   

活动的，活性的

参考例句：

• "I didn't say we'd got to stop activating the masses! “我并没说就此不发动！ 来自子夜部分
• Presumably both the very small size and activating influence of fluorine atoms contribute to this exception. 这大概是由于氟原子半径小和活性高这两个原因的影响，氟原子对这种例外做出了贡献。

23 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

24 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

25 briefly   

adv.简单地，简短地

参考例句：

• I want to touch briefly on another aspect of the problem.我想简单地谈一下这个问题的另一方面。
• He was kidnapped and briefly detained by a terrorist group.他被一个恐怖组织绑架并短暂拘禁。

26 makeup   

n.组织；性格；化装品

参考例句：

• Those who failed the exam take a makeup exam.这次考试不及格的人必须参加补考。
• Do you think her beauty could makeup for her stupidity?你认为她的美丽能弥补她的愚蠢吗？

27 prospect   

n.前景，前途；景色，视野

参考例句：

• This state of things holds out a cheerful prospect.事态呈现出可喜的前景。
• The prospect became more evident.前景变得更加明朗了。

28 ethics   

n.伦理学；伦理观，道德标准

参考例句：

• The ethics of his profession don't permit him to do that.他的职业道德不允许他那样做。
• Personal ethics and professional ethics sometimes conflict.个人道德和职业道德有时会相互抵触。

29 ethical   

adj.伦理的，道德的，合乎道德的

参考例句：

• It is necessary to get the youth to have a high ethical concept.必须使青年具有高度的道德观念。
• It was a debate which aroused fervent ethical arguments.那是一场引发强烈的伦理道德争论的辩论。

30 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

31 outweigh   

vt.比...更重，...更重要

参考例句：

• The merits of your plan outweigh the defects.你制定的计划其优点胜过缺点。
• One's merits outweigh one's short-comings.功大于过。

32 justified   

a.正当的，有理的

参考例句：

• She felt fully justified in asking for her money back. 她认为有充分的理由要求退款。
• The prisoner has certainly justified his claims by his actions. 那个囚犯确实已用自己的行动表明他的要求是正当的。

33 tightened   

收紧( tighten的过去式和过去分词 )； （使）变紧； （使）绷紧； 加紧

参考例句：

• The rope holding the boat suddenly tightened and broke. 系船的绳子突然绷断了。
• His index finger tightened on the trigger but then relaxed again. 他的食指扣住扳机，然后又松开了。

34 organisation   

n.组织，安排，团体，有机休

参考例句：

• The method of his organisation work is worth commending.他的组织工作的方法值得称道。
• His application for membership of the organisation was rejected.他想要加入该组织的申请遭到了拒绝。