环球英语 — 152：Changing Blood Groups

　　Voice 1
Hello, I’m Mike Procter.
Voice 2
And I’m Ruby¹ Jones. Welcome to Spotlight². This programme uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live.
Voice 3
“My name is Anna. I am just a normal person. But I help to save many people’s lives. How? Well, three times a year, I give blood. To do this, I go to my local blood donor³ centre. At the centre, the health worker asks me some questions. She wants to make sure that my blood is free from any harmful bacteria. Then, I lie down on a narrow bed. Another health worker places a needle into my arm. A tube leads from the needle to a machine. Slowly, the machine takes out some of my blood - almost half a litre! A system of tubes and plastic bags separates the blood into its different elements: red cells, white cells, platelets and plasma⁴. Doctors can use these four elements to treat different medical problems. So one half-litre of my blood could help four different people!”
Voice 1
There are many people around the world like Anna. They know that their blood can save lives. This is because doctors depend on a ready supply of blood when they operate. They may need to it to replace a patient’s blood, lost during the operation. And, some people suffer from unusual medical conditions. They often need new, clean blood because their own blood is infected. So, it is important for hospitals to have a large supply ready at all times. And there is always a demand for new people to give blood.
Voice 2
In theory, the process is simple. People give some blood. Health workers then store the blood under controlled conditions. It is then ready for use when the doctors need it. But in real life, it is not that easy. Doctors cannot just give any kind of blood to their patients. The reason for this is genetic⁵. The genes⁶ passed on to us from our parents dictate⁷ what our blood group will be. If a person receives blood from the wrong blood group, it could have a bad effect on their health. It may even result in death. Health workers must supply patients with blood that fits their blood group.
Voice 1
There are four kinds of blood group: O, A, B and AB. The most common blood kind, or type, is O. Any patient needing fresh blood can receive type O. Scientists believe that type O is the oldest blood group. They say that A and B groups developed from the O blood type as human history developed. Later, people moved around the world. They often married individuals with a very different genetic history. The scientists believe that group AB formed by genetic mixing among people with other types.
Voice 2
Type A blood contains a particular kind of sugar molecule⁸. This sugar molecule attaches itself to the surface of the red blood cells. And it is an antigen - it can make the body react as if it is being attacked by harmful bacteria. This is what would happen if doctors gave B or AB type blood to someone with blood type A.
Voice 1
Type B also has sugar molecules⁹ on its red blood cells - but a different kind of sugar from type A. These sugar molecules are also antigens. However, in a person with type B blood these antigens would reject type A or AB blood.
Voice 2
It may be no surprise to hear that AB blood contains both A and B type sugar molecules! And both sugar types act as antigens in AB blood too. People with type A or type B blood cannot accept type AB. But some people with type AB blood can accept any type of blood.
Voice 1
Well, we can see that different blood groups may cause problems when it comes to treating patients. But a new scientific discovery may be about to change all that. Doctors in Denmark and Sweden have developed a new medical process - a way to change blood types A, B and AB into type O. Remember, type O can be given to anyone. So, how is this change possible?
Voice 2
The process seems very simple. The scientists searched different bacteria for some enzymes¹⁰. Enzymes help to speed up chemical processes. The scientists mixed some of these enzymes with blood samples. And they found that two particular enzymes produced interesting results. These enzymes cut off the sugar molecules from the surface of the red blood cells. After one hour, blood samples of type A, B and AB were all free from sugar molecules. They had changed into type O blood.
Voice 1
The processed blood still needs to be tested on patients. But the scientists are very hopeful about the future of this discovery. Professor Henrik Clausen, from the University of Copenhagen in Denmark, led the research. He said,
Voice 4
“We hope that we can soon move this new process from the laboratory¹¹ to the hospital. This may improve blood supply. And it may also improve patients’ safety when they receive blood transfusions¹².”
Voice 2
People’s ethnic¹³ origin influences what blood group they may be. Most people on the American continent have type O. Type A blood is very common among people from Central and Eastern Europe. Many people of Chinese or Asian origin have type B. And in Japan, China and Pakistan, ten [10] percent have the most rare blood type, AB.
Voice 1
In the 1970s, a Japanese writer called Masahiko Nomi wrote a book. This book suggested that blood types influence the way that people think and act. For example, people with type O blood may be more friendly, type A people may be quieter, type B people - more independent and type AB people - more serious minded. Many Japanese people are very serious about this theory. They may even ask about a person’s blood group when they search for someone to marry! But others believe that blood group is purely¹⁴ a health matter.
Voice 2
Doctor Peter D’Adamo is from the U S A. He wrote a book called ‘Eat 4 Your Type’. The book says that our blood groups should influence what we eat. For example, people with O type blood should eat more meat, but people with type A blood should eat more vegetables, and so on. Many people follow Doctor D’Adamo’s diet ideas. But some scientists say that these ideas have yet to be proved.
 

1 ruby   

n.红宝石，红宝石色

参考例句：

• She is wearing a small ruby earring.她戴着一枚红宝石小耳环。
• On the handle of his sword sat the biggest ruby in the world.他的剑柄上镶有一颗世上最大的红宝石。

2 spotlight   

n.公众注意的中心，聚光灯，探照灯，视听，注意，醒目

参考例句：

• This week the spotlight is on the world of fashion.本周引人瞩目的是时装界。
• The spotlight followed her round the stage.聚光灯的光圈随着她在舞台上转。

3 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。

4 plasma   

n.血浆，细胞质，乳清

参考例句：

• Keep some blood plasma back for the serious cases.留一些血浆给重病号。
• The plasma is the liquid portion of blood that is free of cells .血浆是血液的液体部分，不包含各种细胞。

5 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。

6 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

7 dictate   

v.口授；(使)听写；指令，指示，命令

参考例句：

• It took him a long time to dictate this letter.口述这封信花了他很长时间。
• What right have you to dictate to others?你有什么资格向别人发号施令？

8 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

9 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

10 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

11 laboratory   

n.实验室，化验室

参考例句：

• She has donated money to establish a laboratory.她捐款成立了一个实验室。
• Our laboratory equipment isn't perfect,but we must make do.实验室设备是不够理想，但我们只好因陋就简。

12 transfusions   

n.输血( transfusion的名词复数 )；输液；倾注；渗透

参考例句：

• Still, transfusions have apparently never spread the disease, even among hemophiliacs. 还有，输血很明显从未传播过这种病，即使在血友病人之间也是如此。 来自英汉非文学 - 生命科学 - 口蹄疫疯牛病
• Blood transfusions are a special, limited example of tissue transplantation. 输血是一个特殊的、有限制的组织移植的例子。 来自辞典例句

13 ethnic   

adj.人种的，种族的，异教徒的

参考例句：

• This music would sound more ethnic if you played it in steel drums.如果你用钢鼓演奏，这首乐曲将更具民族特色。
• The plan is likely only to aggravate ethnic frictions.这一方案很有可能只会加剧种族冲突。

14 purely   

adv.纯粹地，完全地

参考例句：

• I helped him purely and simply out of friendship.我帮他纯粹是出于友情。
• This disproves the theory that children are purely imitative.这证明认为儿童只会单纯地模仿的理论是站不住脚的。