Xenotransplant: a surgical procedure in which tissue or whole organ is transplanted from one species to another. (www.encyclo.co.uk)
Immunosuppression: lowering the body’s normal immune response to invasion by foreign substances. This can be deliberate (as in lowering the immune response to prevent rejection of a transplanted organ) or incidental (as a side effect of radiotherapy or chemotherapy for cancer).
(www.encyclo.co.uk, )
Development in 1954
The first ever successful transplant - a kidney transplant between teo identical twins “But in 1954 at the Peter Bent Brigham Hospital in Boston, a special kidney transplant case would succeed and teach medicine a great deal by confirming Medawar's results. Richard and Ronald Herrick were identical twins, but Richard was dying of kidney disease. Ronald donated one of his kidneys, and it was successfully transplanted into Richard. Because they were identical twins, the organ did not appear foreign to Richard's body, which did not reject it.”
The development was the idea of rejection of transplants through the immune system -immune response. This then lead to the use of immunosuppressant’s such as cyclosporine.
Transplants are not the idea of the 21st or 20th century. Transplants have been mentioned in the myths of ancient Greeks, and the transplants of eyes and skin were the first to be attempted. The kidney was the first ever imbedded organ to be transplanted. The first kidney transplant patients had a good recovery at the start, but then died soon after.
It was only after Peter Medaw discovered that recipients formed antibodies against their transplants that the first successful transplant occurred- between two twins who would not reject their twins kidney as it was the same as theirs - not a foreign object.
After this, Doctors tried to find ways of “tricking” the body into not rejecting the transplanted new, healthy organ. The first way was by bombarding the patient with X-rays, but this lead to the death of many patients. Doctors then discovered that drugs, such as cyclosporine could be used to suppress the immune system. The above development of ideas and techniques led to today’s transplant success. (www.discoveriesinmedicine.com )
1) Trends by number of donors
The graph shows that the number of donors is staying at a similar figure from1995 to 2004 i.e. there isn’t much difference between the numbers of donors each year. The estimated mean of the number of donors between the years 1995 and 2004 is seven hundred and eighty eight [788]. There is a difference of one hundred and sixty-five [165] between the years 1996 and 2003, this shows the decrease in the number of donors in eight years. It can also be seen that as the number of donors increases, the number of transplants also increases.
2) Trends number of people receiving transplants
The graph shows that the number of people receiving transplants is staying the same. As the number of people receiving transplants increases the number of people on the waiting list decreases.
3) Trends number people on transplant list
The graph shows that the number of people needing transplants is increasing each year. The number of people needing transplants each year exceeds both the number of donors and the number of people receiving transplants. The estimated mean of the number of people on the transplant list is six thousand seven hundred and sixty two [6762].
What problems do these trends show?
The problems that the trends above show are that there are not enough organs and therefore the number of people who need transplants increases. This increases the chances of death as some patient may not be able to survive due to lack of organs. On the other hand some patient may live a bit longer if they are fortunate to get life support machines and other devices that do the job of certain organs e.g. someone who is in need of a kidney could be connected to a dialysis machine. If the number of donors is less than that of the people who need transplants, this will mean the government will have to spend more money on devices and machines. This means it is costing the NHS money ,as if all the patients who needed a transplant on 1 January 2007 - 6200 patients, received one; it would save the NHS £150m per year. The other economic factor is many of these patients who need a transplant die in waiting, meaning they are not earning money, not funding the economic life of Britain and not paying the taxes needed to fund the NHS.
How can present and future developments in Science and Technology overcome some of these problems?
Science and technology may help overcome these problems by the research being done intothe possibility of Xenotransplants, where a organ is transplanted from one species to another.
Originally it was thought that primates could be used, such as chimpanzees, as their genome is “98% identical with the human genome” but many scientists think this unethical as chimpanzees, and many other primates, are endangered species. The next, more likely alternative is to use pigs for this purpose, as they are of similar size and it would ethically ok as we already farm these animals and we already use heart valves successfully for replacing those damaged in humans.
However the human immune system will attack any pig tissue ruthlessly. The only way to overcome this is to genetically modify the pig, which is a possibility due to the advances in science.
What are the advantages of using animals as organ donors for humans?
- Animals are readily available, this means that the rate of people on the transplant list will decrease.
- It will save the government money.
- Easily make up for shortage.
- This could mean saving for NHS, more taxes to help pay for more research.
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No social damages as you know your relatives/friends organs are in someone else’s body. (www.yahoo.com)
What are the disadvantages of using animals as organ donors for humans?
- There is a small possibility that there could be a transfer of pig or primates diseases with the transplant to the human which could seriously harm the patient and could even cause a large epidemic
- Animals have rights. Many believe that animals too have rights, just like humans, and therefore have the right to live without fear of murder and not be killed of the purpose of helping humans by providing organs for transplants and therefore we should not exploit the animals for our benefit.
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Scientists are “playing God” by genetically modifying the animals, and as said with argument on GM crops, we have yet to know what affect this will have on the environment and future generations. (www.yahoo.com)
In my opinion, I think humans should not use other animals for organ transplant because some animals will be endangered and may later become extinct. Moreover humans could also be at risk because animal diseases could spread to humans because certain viruses could be introduced into the recipient’s body.
