РефератыИностранный языкXeXenotransplantation Essay Research Paper XenotransplantationThere is a

Xenotransplantation Essay Research Paper XenotransplantationThere is a

Xenotransplantation Essay, Research Paper


Xenotransplantation


There is a shortage of organs for clinical transplantation all around the world.


Many patients waiting to receive new organs die because we are unable to receive enough


organs: there aren’t enough donors. We are now testing the implantation of other


species’organs into the human body, that would be a great solution in ending organ


shortage. There is a problem though, the human body does not cooperate well with other


non-human organs. Rejection is the worst problem we have encountered yet. New


researches are helping us understand the mechanisms of trasplanting organs without


rejection. Cells or tissues from other species can be very usefull to the human race. They


can help cure some very deadly deseases such as cancer, AIDS, diabetes and liver failure.


This great technology can also bring disaterous effects to the human races. The


transplanted tissue can cary an unknown infection that may not harm that specie in


particular but might be deadly to humans. Also as a worse case scenario, an infection can


start a life-threatening pandemic. “The transplanting of animal organs, tissues, and cells


into human beings is likely to become more common in the future but such transplants


raises crucial issues that merit further investigation and discussion.”(1)


There are atleast 50,000 patients waiting for transplant in the U.S.A but there are


less then 5,000 donors annually. If we can find a way to make our bodies accept organs


for other species, we will create a new “lifeline”. However, xenotransplantation also


raises some medical, legal, and ethical issues. The concern of most doctors is the


rejection of the organs from the body and the birth of a new infection or disease. To find


out more on these possibilities, we have to monitor all patients who receive organs and all


the species who donate the organs but the species will also need screening for


“pathogens”. A possible solution to minimize the risk of infection would be to raise


animals in an essentially germ free environment. However, if the animals are accidentally


released from the controlled environments, the whole experiment would be ruined.


Successful xenotransplantation would put an end to people on a waiting list.


People wouldn’t have to wait years to receive an organ and people shouldn’t die on a


waiting list. Some advocates say that successful xenotransplantation could save


thousands of lives because human organs aren’t keeping up with demand. Back in 1994, a


bit over 7,600 people donated organs but there was 37,000 people on waiting lists and


50% of these people waiting to received an organ died before they received their organ.


Advocates also say that some religions may forbid some people in participating to


xenotransplantation. It is not in their beliefs. Then there is also animal rights group that


would cause problems. They are totally against the use of animals in scientific research.


Also what some people are starting to think is that if xenotransplantation works out well,


no one would volounteer on donating their organs but why would we still want human


donors if we can now implant organs from other species? There are also financial issues


as how much the hospital should charge and if the insuurance cmopanies sho

uld cover


this operation.


“The food and Drug Administration has already established a broadly constituted


advisory committee, including both expert scientists and lay representatives to examine


xenotransplantation.However, due to the aspects of public risk associated with


xenotransplantation, initial discussions must be focused on the ethical issues.”(2)


There are a couple of things included in the legal issues. First of all there is the


Debate on the owner of the animal and the long term affect it will cause the animal. Also


if we artificially create an animal, how it will react to the natural world. Then, there will


also be some license fees for the use artificially created animals for their organs. This


types of laws are specifically excluded in U.S.A. and in Britain, but since the


“oncomouse” was patented in 1988, there now exist hundreds of laws for transgenic


procedures. Doctors are asking themselves if these are new inventions or rearrangements


of the genetic code. “Should laws of nature, animal, and human life be commodified in


this way?”(2)


We should always put up a caution on the possible long-term genetic problems.


Anything is possible and we have to be very cautious. Any little change in the genetic


code of animals is a cause for concern. The recent British experince of “the mad cow


disease” is evidence of this concern. To reduce these risks, we are now using transgenic


pigs as donors but there are only a few hospitals will be chosen as a center for


xenotransplant surgery. Other hospitals may be tempted to revive the xenotransplantation


program by using organs from baboons. It might advance their reputations, reduce the


cost to the patient and illiminate the license fees.


The biggest problem doctors are having with the transplant is that a body’s


immune system reacts to these strange tissues and organs by destroying them. The two


materials (human and animal) are not compatible. If we try implanting a pig’s liver in a


human body, within minutes it’ll become a swollen and a blody mess. As soon as there is


a new organ implanted, our antibodies rap the organ and begin the “hyper-acute”


rejection process. Doctors and scientists find this a great “pitty” because the structure and


size of a pig’s organ is a perfect replacement of a human organ.


A way that scientist are now using to control this rejection is to distract the


antibodies so they don’t see the transplanted organ. One of the test they tried was “using


extra doses of culpable sugars to mop up antibodies before these antibodies can stick to


the xenograft.” They got this idea because they had tried it on a baboon and it retained the


transplanted pig hart much longer then if they hadn’t received these sugars intravenously.


But on a human, the amount of sugar needed to distract the antibodies will be poisonous.


Up to this date, every experiment failed either because the organ was rejected or


failed to function. In some cases, the use of immunosuppressive drugs to prevent


infections, led to infections. We are unable to prolong human life with transplanted


organs. But we are able to treat some other human illness with the use of animals. Pig


heart valves are routinely used un cardiac surgery, and insulin from cattle is used to treat


diabetes.

Сохранить в соц. сетях:
Обсуждение:
comments powered by Disqus

Название реферата: Xenotransplantation Essay Research Paper XenotransplantationThere is a

Слов:1159
Символов:7677
Размер:14.99 Кб.