说实话，一点也不喜欢这篇文章~

    Throughout the world there is a shortage of human organs for transplants. In Britain, for example, 6 O00 people are waiting for organs -- 5 000 for kidneys, and the remainder for hearts, lungs and livers. However, only about I 750 kidney, 500 heart or heart and lung, and 650 liver transplants are carried out each year. And the waiting list increases at five per cent a year. In the United States only half of the 30 000 in need of organs receive them.
    在整个世界，供人类移植的器官都相当短缺。例如，在英国，6000人在等待人体器官——5000人需要肾，其余的需要心脏、肺和肝脏。然而，每年只有大约1750个肾，500个心脏，或5000个肺和650个肝脏的移植能够实施。并且，等待的人每年正以5%的速度增加。在美国，等待人体器官的30000个人中只有一半人能够得到器官。


    Hence the great interest in animal-to-human transplants, known ax xenografts or xenotransplants (from the Greek word xenos, meaning strange or foreign), which most scientists believe ix the only long-term solution to the organ shortage. There have been attempts at xenotransplants since the beginning of this century but none has been successful; the longest survivor was a 20-day-old baby called Fae, who in 1984 was given the heart of a baboon.
    因此人们对动物和人之间的器官移植---即人们所熟知的异种移植或异种器官移植---非常感兴趣，许多科学家认为它们是解决人类长期以来器官移植短缺的唯一方法。从本世纪之初起，人们多次尝试了异种器官移植手术，但是没有一例成功。存活时间最长的幸存者是一个叫费依的刚出生20天的婴儿，他是在1984年被植入了狒狒的心脏。


The main problem with any organ transplant is that the immune system of the patient receiving the organ sees the transplant organ as an invader. The immune system therefore launches a massive attack on the invader, activating enzyme' enzymes known as complement, which attack the foreign body, eventually killing the patient as well. This rejection has been overcome when transplanting organs between humans by the close matching of tissue and the long-term use of drugs known as immuno-suppressants, first introduced just over ten years ago. With xenotransplants, however, rejection is even more severe; a normal pig's heart, for example, transfused with human blood can be destroyed in 15 minutes.
    任何器官移植的主要问题就是，接受器官移植的病人的免疫系统把植入器官看作是侵入者。因此，免疫系统会对入侵者发动大规模攻击，激活人称防御素的酶来攻击异体，最终也会杀死病人。对于人体间的器官移植，人们通过对的组织进行严格匹配和长期使用称作免疫抑制剂的药物，克服了排异现象。然而对于异种移植，排异现象更为严重，例如，要给一头正常猪的心脏输入人类的血液，它将在15分钟内死亡。


     So for the past few years a lot of research has gone into preparing animal organs by raising animals that have been genetically altered; they are known as transgenic breeds. Animal embryos are being injected with a human gene to produce human complement inhibitors, which control the release of complement, so that after a transplant the human complement "sees" the transgenic animal organ as if it were human.
    在过去的几年中，人们做了大量的研究，通过喂养遗传基因已经被改变了的动物来培养器官，这些动物被称作转起因动物。人们将人类的基因注入动物胚胎，正以产生人体的防御素的抑制剂，这种抑制剂可控制防御素的释放，在移植手术后，人体的防御素会把转基因动物的器官被看成是人类的器官。


     The preferred animals for xenotransplants are not other primates, once considered the best candidates for xenografts, but pigs. Ironically, other primates resemble humans too closely; the same viruses that infect monkeys and apes may infect humans, and a primate organ transplant could pass on fatal diseases; Aids probably originated as a monkey virus that somehow infected humans. Pigs' organs, though, are close in function and size to those of humans, yet distant enough not to carry viruses fatal to humans. And pigs are also cheap and easy to breed.
    适于异体器官移植的动物是猪而不是其他灵长目动物。灵长目动物曾经被认为是异体移植的最好的选择。具有讽刺意味的是，灵长目动物和人类的非常相似，传染给猴子和猿的病毒同样会传染给人类。而灵长目动物的器官移植可能会传播致命的疾病。艾滋病最初或许来源于猴子体内的一种病毒，并通过某种渠道传染给了人类。而猪的器官在大小和作用上和人类的器官非常相近，又足以相异到不会给人类带来致命的病毒，而且猪既便宜也比较容易饲养。


    A British biotechnology company called Imutran, which is based in Cambridge, is planning the world's first pig-to-human heart transplant some time this year as part of its clinical trials. Last year the Cambridge scientists successfully transplanted transgenic pigs' hearts into monkeys; some of the monkeys were still alive after 60 days, beating the previous best results of scientists in the United States who only achieved a maximum survival rate of 30 hours.
    一家设于剑桥的英国生物工程公司Zmutran公司，计划今年进行世界第一例猪---人的心脏移植，并将其作为临床试验的一部分。去年。剑桥科学家们成功地将转基因的猪心脏移植到猴子体内，其中的一些猴子存活超过60天。这一成绩打破了早先美国科学家所创造的最高存活率为30天的记录。


     If Imutran's research continues as expected, transgenic pigs' organs, including kidneys and lungs, could be generally available by the year 2000. '~This will give hope to hundreds of thousands of patients around the world who would otherwise die waiting for a heart, lung or kidney," said Christopher Sampler, Imutran's Chief Executive. The transplants of pigs' livers are not being considered at this stage.
    如果Imutran公司的研究如期进行下去，那么转基因猪的器官，包括肾脏和肺，到2000年就可以得到广泛利用。克里斯特夫·萨姆勒， “这将给世界上成千上万的病人带来希望，不然他们会在等待心脏、肺或者肾脏死去”。而猪的肝脏的移植在这个阶段尚未被考虑。


     然而，异体移植需要克服的不仅是科学上的障碍，还要克服道德上的障碍。猪的胰岛素已被用于治疗糖尿病患者，猪的心脏瓣膜也被用于心脏修复手术，因此，使用动物器官似乎不会招来太多的抗【度受河蟹器】议。但是，预计动物权利的倡导者不会接受饲养然后杀掉动物供医学使用的做法。而且，正如苏格兰倡导保护动物协会主任——莱斯·威尔德指出的，当猪的器官被取出后，怎么处理这只猪的其他部分呢？难道这些肉又用来被人类消费吗？“如果这样的话，请记住：猪的体内包含着人类的某些基因，这是否是同类相食呢？”

最后一段原文由于度受抽筋被视为广告，所以就以图片的形式发出来，大家就将就着看了哈
OVER~

谢谢咯

非常感谢楼主，楼主强大，跪谢。