Реферат по предмету "Иностранный язык"


Gene Therpy Essay Research Paper Human Gene

Gene Therpy Essay, Research Paper

Human Gene Therapy “To much of the general public, genetic engineering is a vague notion of high tech manipulation of plants and animals. Its results too difficult to understand” (Cowen 18). It was not until this century that humans were granted a glimpse into the possible origins of biological inheritance. Scientists have only been aware of the existence of the hereditary factors, known as genes, for a little more than one hundred years, and the molecular nature of the gene for about twenty-five years. For the rest of our history, we have lived in absolute ignorance of genetics. Genetic engineering is a growing area of science capable of delivering amazing treatments to many hereditary ailments. Doctors estimate that at least ten per cent of diseases are genetic in origin. There is at present no cure for genetic defects. Gene therapy is a tremendous breakthrough in modern technology, benefical only if it is used to aid the medically inflicted. Although human gene therapy is a relatively new branch of science, there are unlimited potential benefits; therefore, the genetically imperfect individual should have the option to assume these risks and undergo experimental procedures to improve his or her overall health. As a result of recent advances in medical science, researchers believe that a gene can be transplanted into humans suffering from severe diseases. Such gene transplants can alleviate or perhaps even cure diseases for which no adequate treatment presently exists. The treatment is called human gene therapy, which is one of a series of emerging genetic techniques commonly called genetic engineering. These sciences are based on our emerging knowledge about how genes work. Genes, consisting of a chemical called DNA, direct the various traits of each individual’s body (Avigen). According to David Suzuki, Professor of Biology at the University of British Columbia, “The system may be thought of as a tinkertoy set, in which sticks, wheels, and blades can be snapped together into windmills, castles, cars, and a diversity of other forms limited only by the child’s imagination and patience” (22). Together, the total genetic information contained in genes comprises a genome, a unique genetic blueprint for each organism (Friedman 244).When the DNA information of a particular gene contains mistakes, the gene may not function properly. Sometimes the malfunction will not be serious, but other times it will result in a severe genetic disease. Examples of some genetic diseases are cystic fibrosis, sickle cell anemia, and hemophilia (Reuters Foundation). Hemophilia, for instance, is caused by the malfunctioning of the gene responsible for blood clotting (Chadwick 147). As more is learned about human genetics, scientists are discovering that diseases such as diabetes, cancer, heart disease, and some manic depressive illnesses result in part from faulty DNA information, and therefore also hold the potential of being remedied by human gene therapy. Human gene therapy is a possible alternative to the painful, expensive approach to the treatment of some genetic diseases. Gene therapy technologies are now making it possible to provide treatments that twenty years ago were hardly dreamed possible. These new technologies will bring about a whole new era in medicine. The basic idea behind gene therapy is to insert normal genes with correct information into the DNA of the cells that contain malfunctioning genes. Adding genes in this way is called gene insertion. The added genetic information allows these cells to function properly and can reduce or eliminate the signs or symptoms of the disease. For example, instead of repeatedly treating a hemophiliac with a blood coagulant, the insertion of the correct genetic material into his cells enables those cells to make their own clotting factor (Chadwick 147). Every year thousands of ailing children are born with cystic fibrosis, which leads to a clogging of the lungs, and to problems with digestion and other functions. Because a recessive gene possessed by one in every twenty Caucasians is responsible for the abnormality, one in every four hundred couples risks giving birth to afflicted progeny (Chadwick 135). Although improvements in care and treatment mean that people with cystic fibrosis can now live for up to twenty-five years, there is no cure. But there is gene therapy. Human gene therapy is capable of treating this disease which is stealing the lives of many young people. A much rarer but nevertheless well known genetic disease, is severe combined immunodeficiency (SCID). Children with this condition have a defect in both copies of a gene which is required for the proper functioning of the immune system. The children can be kept alive but they have to live in sterile plastic bubbles to isolate them from bacteria and viruses. These children live horrible lives then die of infections which only keep the healthy population in bed for a couple of days. Again, while there are treatments, there is no cure. However, the cure is obvious. If the children are ill because they have two bad copies of a gene, they could be given a good copy of the gene that would be healthy like their parents’. The new genetic technology also benefits these individuals because they are now less prone to pass the disease on to their offspring.Another disease treated through gene therapy is sickle cell anemia. This disease is caused by a single DNA base change in the genes of its sufferers. The substitution alters the codon for a single amino acid in a polypeptide chain of a single red blood protein so that it collapses when oxygen levels in the blood decrease, causing normally smooth, round red blood cells to crumple into the characteristic shape of a sickle. The sickled red blood cells impair blood circulation and cause obstructions, pain, and tissue damage (Friedman 246). With gene insertion, specialized doctors can correct the genetic substitution and allow the individual to live a life free of the discomfort many people take for granted.

Yet another preventable, rare, and tragic disease cursing today’s youth is known as Lesch-Nyhan syndrome. Gene therapy is the only preventative therapy known at this time. The children appear healthy at birth, but within weeks or months they develop cerebral palsy. Prenatal genetic testing can be used to identify a carrier of this disease in the womb. The children are severely mentally handicapped, and they make constant writhing movements. The build up of purines in their blood stream brings continual pain. The children involuntarily mutilate themselves, often biting off parts of their tongue and lips. Sometimes the only way to prevent this is to remove all of their teeth. These children do not die until they are in their teenage years. Is it not simple to understand why people who want to be parents, but whose potential children are at high risk of such a disorder, may see genetic screening as a mercy? The genetic benefits are of special relevance when alternative therapies for a given disease are poor or nonexistent. Diseases such as AIDS and cancer, for which there is no cure, are currently being researched. Experiments are already being done with possible methods of gene therapy. Once these methods are developed further, they will revolutionize the health care system. Currently, a large amount of money is being apportioned to AIDS and cancer treatments. Once these diseases can be prevented through gene therapy they will no longer need to be treated. This will be a benefit to society through decreases health care costs.Human gene therapy is clearly the most cost efficient disease treatment in the market today. The cost of preventing disease with new genetic technology is minimal compared to the extended costs of repeated treatments of related symptoms. Also, if the patient is prevented from obtaining the disease, it follows that his offspring will not be as likely to carry the disease, thus reducing costs further.Not only is human gene therapy cost efficient, but it also results in a higher quality of life for the individual. When the disease is avoided altogether, the person is never subjected to the pain caused by the illness. Also, he is granted independence and freedom from following strict regimens currently prescribed to ease symptoms of the disease. And last but not least, the length of the individual’s expected life is increased dramatically. Most patients born with a genetic disease are not expected to live to see their thirtieth birthday. With gene therapy, this is no longer an issue. The benefits of this increased quality of life are priceless. The idea of developing a genetic therapy for disorders is founded on the principle that it will be in the best interest and may alleviate the suffering of the individual undergoing the therapy. Some people claim that tampering with genes to save lives can be compared to doctors and scientists “playing God.” These same people do not refuse medical treatment when they are ill. Whether prescribing antibiotics or inserting corrected genes doctors still are affecting the health of an individual. So, what is the difference? Attackers of gene therapy have yet to answer. The fact remains that gene therapy is a the most practical use of knowledge to treat disease.The goal of biomedical research is, and has always been to alleviate human suffering. Every previously mentioned disease and inherited disorder can be treated by the miraculous techniques of gene therapy. “Scientists believe that each of us carries at least three lethal genetic defects in a recessive state” (Mabie 24). “Desperately ill patients should have the right to assume risks in hope of improved health – just as others have the voluntary decision to submit their bodies to experimental drugs” (Walters and Palmer 25). The potential benefits are plain to see. Even if they were not, sheer curiosity makes the prospect of gene therapy hard to resist. “How can we not do it? We used to think the fate was in the stars,” observed James Watson. “Now we know, in large measure, our fate is in our genes” (Mabie 28).

Cowen, Robert C. “The Science, Genetic Engineering.” Christian Science Monitor. September 26, 1986: 18-19. Friedman, Theodore. “Progress Toward Human Gene Therapy.” Science. June 16, 1989: 244-250. “Introduction to Gene Therapy.” 25 January 1999. Avigen. http://www.avigen.com/gene_therapy.htm(13 March 1999) Mabie, Margot C. Bioethics & The New Medical Technology. New York: Athenaeum, 1993. “Genetic Testing: The Benefits.” Spring 1998. Reuterslink Extra :Issue No 8. Reuters Foundation. http://www.foundation.reuters.com/genben.htm(13 March 1999) Suzuki, David and Peter Knudtson. Genetics; The Clash Between the New Genetics and Human Values. Cambridge: Harvard University Press, 1989. Walters, LeRoy and Julie Gage Palmer. The Ethics of Human Gene Therapy. New York: Oxford University Press, 1997.




Не сдавайте скачаную работу преподавателю!
Данный реферат Вы можете использовать для подготовки курсовых проектов.

Поделись с друзьями, за репост + 100 мильонов к студенческой карме :

Пишем реферат самостоятельно:
! Как писать рефераты
Практические рекомендации по написанию студенческих рефератов.
! План реферата Краткий список разделов, отражающий структура и порядок работы над будующим рефератом.
! Введение реферата Вводная часть работы, в которой отражается цель и обозначается список задач.
! Заключение реферата В заключении подводятся итоги, описывается была ли достигнута поставленная цель, каковы результаты.
! Оформление рефератов Методические рекомендации по грамотному оформлению работы по ГОСТ.

Читайте также:
Виды рефератов Какими бывают рефераты по своему назначению и структуре.

Сейчас смотрят :

Реферат Народні традиції у вихованні учнів початкових класів
Реферат Белые цапли
Реферат Пріоритети і напрямки вдосконалення чинної макроекономічної політики
Реферат Fascisms In Germany And Italy Essay Research
Реферат Classroom Discipline Essay Research Paper Classroom DisciplineAt
Реферат Consequences Of The Mongol Inv Essay Research
Реферат Анализ хозяйственной деятельности предприятия общественного питания
Реферат Устав Интерпола и международное сотрудничество в сфере борьбы с преступностью
Реферат The Awakening Public Controversy Essay Research Paper
Реферат Разработка технологического процесса ЕО автомобиля ЗИЛ-130
Реферат Исторический портрет Ивана IV Васильевича Грозного
Реферат Рецензируя прочитанное по творчеству Михаила Лермонтова
Реферат Самостоятельность в математической деятельности
Реферат «Мы жили обычной жизнью»? Семья в Берлине в 30-е 40-е г г. ХХ в
Реферат Сравнительный анализ Северо-западного и Западно-Сибирского районов