Sacrificed to Science?

　　Professor Colin Blakemore works at Oxford University Medical School doing research into eye problems and believes that animal research has given humans many benefits:The use of animals has been central to the development of anaesthetics, vaccines and treatments for diabetes, cancer, developmental disorders…most of the major medical advances have been based on a background of animal research and development.

　　There are those who think the tests are simply unnecessary. The International Association Against Painful Experiments on Animals is an organization that promotes the use of alternative methods of research which do not make animals suffer. Their spokesman Colin Smith says:

　　Animal research is irrelevant to our health and it can often produce misleading results. People and animals are different in their reactions to drugs and in the way their bodies work. We only have to look at some of the medical mistakes to see this is so.

　　But Professor Blackmore stresses:It would be completely irresponsible and unethical to use drugs on people that had not been thoroughly tested on animals. The famous example of thalidomide is a case for more animal testing, not less.

　　The birth defects that the drug produced were a result of inadequate testing. If thalidomide were invented today, it would never be released for human use because new tests on pregnant animals would reveal the dangers.

　　Another organization that is developing other methods of research is FRAME. This is the Fund for the Replacement of Animals in Medical Experiments. It recognises that many experiments still have to be done on animals and is aiming for Reduction, Refinement and Replacement of animals in experiments. In 1981, it established a research programme to improve and expand non-animal testing. Increasingly, new technology is making it easier for us to find alternative methods of testing.

　　Computer models can be used to simulate the way that cells work and to try to predict the toxicity of chemicals. Data from previous animal experiments is used to develop a computer model which will predict what will happen if you add a chemical with an unknown biological effect to a substance. The eventual aim of computer modeling is to reduce the number of animals used in experiments.

　　The Lethal Dose 50 test (LD50) may also be replaced. In the original test, all the animals in a test group are given a substance until half of them die. The test indicates toxicity. A method using a fixed amount, which gives the same eventual information but uses fewer animals and does not require that they die, may replace the LD50. Many other new techniques are now available that enable more research to be done in the test tube to see if chemicals produce harmful biological effects.

　　The number of animals used in laboratory tests has declined over the last 20 years. This is partly due to alternatives and partly to the fact that experiments are better disigned so fewer need to be used - healthier animals provide better experimental results. For example, it used to take 36 monkeys to test a sample of polio vaccine, now it takes only 22. Also, lack of money has reduced the number of animals used - they are expensive to buy and expensive to keep.

　　Birmingham University now has Britain's first department of Biomedical Ethics. Professor David Morton of the department is involved in animal research and is concerned with reducing animal suffering as much as possible. Animals spend 95% of their time in their cages and refinement also means making their lives better when not undergoing tests. This includes keeping them in more suitable cages, allowing social animals like dogs to live together and trying to reduce the boredom that these animals can experience.

　　In Professor Morton's laboratory, rabbits live together in large runs, filled with deep litter and boxes that they can hide in. The researchers have also refined some experiments. In the US, one experiment in nerve regeneration involves cutting a big nerve in a rat's leg, leaving its leg paralysed. In Morton's lab, the researcher cuts a small nerve in the foot. He can see if it can regrow and the rat can still run around its cage.

　　Even with these new developments in research, only a tiny proportion of all tests are done without using animals at some stage. The use of animals in experiments cannot stop immediately if medical research is to continue and consumer products are to be properly tested, and Professor Blakemore believes that sometimes there are no alternatives:

　　Wherever possible, for both ethical and scientific reasons, we do not use animals. But cells live in animals and we can only really see how they behave when they are inside animals. We cannot possibly reproduce in a test tube or a computer model all the complex reactions of the body to a drug or a disease. When it comes to research into heart disease and its effects on the body, or diseases of the brain for example, we do not have adequate substitutes for the use of animals.

　　As research techniques become more advanced, the number of animals used in experiments may decrease, but stopping testing on animals altogether is a long way away.

　　為科學而獻身

　　科林·布萊克默教授在牛津大學醫學院工作，從事眼睛疾病的研究。他相信對動物的研究已使人類獲益匪淺。

　　使用動物對于麻醉學和疫苗的發展，對糖尿病、癌癥和紊亂的治療等極其重要。多數重要的醫學都是以動物研究和開發的背景為基礎的。

　　有些人認為這些實驗毫無必要。國際反動物痙實驗協會是一個提倡使用不使動物痙的替代方法的組織。他們的發言人科林·史密斯說：對動物的研究和我們的健康無關，它常常產生令人誤入歧途的結果。人和動物對藥物的反應及他們身體運作的方式都不同。我們只要看一看醫療失誤就會明白。但布萊克默說：沒有認真在動物身上實驗的藥物大人身上使用，是完全不負責和不合道理的。薩力多胺就是一個著名的例子。它證明需要更多的動物實驗而不是更少的動物實驗。這種藥物引起的先天性畸形是缺乏實驗的結果。如果薩力多胺是現在發明的，它就不會被批準為人類使用，因為在有孕的動物身上實驗會提示其危險。

　　另一個開發其他研究辦法的組織是FRAME，"替代動物醫學實驗基金會"的簡稱。它認識到許多實驗仍然不得不使用動物，該基金會旨在減少使用動物，改良使用動物，甚至替代動物。在1981年，它們設立了一個改進和擴大無動物實驗的研究項目。漸漸地，新科技使我們更易于找到進行實驗可供選擇的辦法。電腦模型可以用來模擬細胞的活動方式和預測化學制品的毒性。以前的動物數據用來開發一個電腦模型，它能預測如果一種物質中加入某種未知生物作用的化學藥品會發生什么。電腦模型的最終目標是減少用于實驗的動物數量。

　　致死計量50實驗(LD50)也可以被代替。在過去的實驗中，實驗群中所有的動物被喂給一種物質，直到其中一半死亡。這個實驗表明其毒性。一種用固定的數量可以得到相同的結論，但是使用較少動物而且不使它們死亡的方法可能代替LD50。現在已有許多其他的技術，可使更多的研究工作在試管中進行，從而發現化學藥品是否產生有害的生物作用。

　　過去的20年里，實驗室里實驗中使用的動物數量減少;其部分原因是由于可供選擇的方法多了，另外部分是由于實驗設計得更好，因為使用更健康的動物能產生更好的實驗結果，所以用的動物減少了。例如，過去常用36只猴子來實驗脊髓質炎疫苗樣本，現在只用22只。缺少資料已使所使用的動物數量減少了 ――購買和使用動物都很昂貴。

　　伯明翰大學現在設有英國首家生物醫學倫里學系。系里的大衛·莫頓教授從事動物研究，并對盡可能地減少動物的痙很關心。動物們在籠子里度過了他們 95%的時間，改良也意味闃不進行實驗時使它和得更好些。這包括在更舒適的籠子里喂養它們，允許像狗那類喜歡合群的動物生活在一起，盡量減少這些動物可能經歷的煩惱。

　　在莫頓教授的實驗室里，大批兔子一起生活，到處是厚厚的干草和箱子供它們躲藏。者們還改進了一些實驗。在美國，神經再生方面的發切斷鼠腳里的一條小神經。他可以看到神經是否可以再生，而老鼠仍在籠子里四處跑。

　　盡管這些研究有了新成果，所有的裕只有極少數在某一階段不使用動物。

　　如果醫學實驗研究還要繼續，消費性門牌號學要嚴格地進行檢驗，這樣在實驗中使用動物就不會立即停止。布萊克莫教授相信有時是無可選擇的。

　　無論在何處，有可能的話，基于倫理和科學的原因，我們不應使用動物做實驗。但是細胞生活在動物體內，只有當細胞在動物體內時我們才能真正看清它們是如何活動的。我們不可能在試管中或電腦模型里復制出身體對疾病或薌的所有復雜反應。涉及到研究心臟病和它對身體的影響時，例如腦內疾病，我們沒有代替使用動物的合適的替代物。

　　隨著研究技術變得更先進，實驗中使用的動物數量可能會減少，但完全停止在動物身上實驗還有很長的路要走。