What is organ transplantation--论文代写范文精选

器官在事故中受损,医生首先评估这个人是否具备移植医学资格。移植中心评估病人的健康和精神状态以及社会支持,寻找可行的器官移植候选人。如果病人是一个移植候选人，必须找到一位器官捐赠者。下面的paper代写范文将对器官移植介绍。

Introduction 
  What is organ transplantation? An organ transplant is a surgical operation where a failing or damaged organ in the human body is removed and replaced with a new one. An organ is a mass of specialized cells and tissues that work together to perform a function in the body. The heart is an example of an organ. It is made up of tissues and cells that all work together to perform the function of pumping blood through the human body. Any part of the body that performs a specialized function is an organ. Therefore eyes are organs because their specialized function is to see, skin is an organ because its function is to protect and regulate the body, and the liver is an organ that functions to remove waste from the blood. A graft is similar to a transplant. It is the process of removing tissue from one part of a person’s body (or another person’s body) and surgically reimplanting it to replace or compensate for damaged tissue. Grafting is different from transplantation because it does not remove and replace an entire organ, but rather only a portion

 The transplant process 
  When a person falls ill because one of his or her organs is failing, or because the organ has been damaged in an accident or by disease, the doctor first assesses whether the person is medically eligible for a transplant. If so, the doctor then refers the individual to a local transplant center. The transplant center evaluates the patient’s health and mental status as well as the level of social support to see if the person is a viable candidate for an organ transplant. If the patient is a transplant candidate a donor organ must be found. There are two sources for donor organs. The first source for organs removes them from recently deceased people. These organs are called cadaveric organs. A person becomes a cadaveric organ donor by indicating that they would like to be an organ donor when they die. This decision can be expressed either on a driver’s license or in a health care directive. In Minnesota, designating your organ donation desires on a drivers license is legally binding.1

  In some states, when a person dies and he or she has not indicated organ donation preferences, the family is asked if they would be willing to donate their relatives’ organs. Some states’ hospitals have policies requiring family consent for organ removal, regardless of whether organ donation wishes are written down.2 Therefore, many organ donation advocacy organizations encourage people to discuss their organ donation preferences with their families to assure that their wishes are known and followed The second source for donor organs is a living person. Living donors are often related to the patient, but that is not always the case. Spouses and close friends frequently donate organs to ailing loved ones. Some people who wish to donate their organs may decide to donate to a stranger. A few not-for-profit organizations maintain lists of willing living donors. For example, the National Marrow Donor Program maintains a list of people willing to donate bone marrow to a stranger and there are a variety of non-related living kidney donor organizations that maintain regional lists of willing donors.3 Individuals who wish to donate one of their organs to a stranger may also initiate a nondirected donation (NDD). Nondirected donors approach either a transplant center or a nationally sponsored organ procurement organization and offer one of their organs for transplant to anyone who may need it.4

 Distributing cadaveric organs 
  If a person does not have a readily available living donor or is ineligible for a living donation because their predicted outcome is questionable, they are placed into a waiting pool for an organ from a cadaver by their transplant center. The United Network for Organ Sharing (UNOS) maintains the list for the national waiting pool. When donor organs become available after a person dies an organ procurement organization (OPO) takes the organs into custody. The OPO then matches the donor organs with the appropriate transplant patients by gathering information about the donor organs and entering it into a computer program. The program takes this information and compares it to information about the patients in the waiting pool.

  After the transplant, the patient embarks on a long road to recovery. If surgery goes well, the patient still must face the possibility of rejection. Rejection is the process where the body fights off the newly implanted organ. Rejection is harmful to transplant success because the body fights off the new organ as it would a virus or bacteria. In fact, the body’s immune system treats the organ as it would any other harmful foreign invader. The immune system makes proteins called antibodies that go to the transplanted organ and try to kill it. In order to hold back the antibodies that threaten the new organ, transplant patients have to take powerful immunosuppressant drugs to keep the level of antibodies down low enough for the organ to integrate into the body and start working.6

 A history of organ transplantation 
  The medical practice of organ transplantation has grown by leaps and bounds over the last 50 years. The major transplant-related medical advances in the last century include: • Successful transplantation of different kinds of organs What began with the kidney has now expanded to hearts, lungs, livers and other organs. 
  • Development of cadaveric and living organ donation practices Deciding who can donate organs has been a flexible and changing process, starting with living donors and then moving to include deceased and brain dead donors. The debate about increasing and restricting the pool of eligible donors continues today. In 2001, living donors outnumbered cadaveric donors for the first time in United States history.7 
  • Development of anti-rejection drugs to increase success Anti-rejection drugs have done wonders to increase the success of organ transplants. During the 1960s and 1970s, immunosuppressant drugs helped increase the success rate of organ transplants. In the 1980s, Cyclosporine was discovered and dramatically improved the success rate for transplant recipients and helped improve patient outcomes.8 
  • Using animal organs for human transplantation (called xenotransplantation) In 1986, the first xenotransplanted organ transplant was performed. This intriguing field of study becomes more attractive to some researchers as the number of people needing organ transplants continues to grow. • Invention and use of the first artificial organs The first artificial heart transplant in the 1980s was closely followed by the news media and the American public. 
  • Splitting organs into pieces (either from living donors or cadaveric donors) The first split liver transplant in 1996 allowed one cadaveric liver to be used among multiple transplant patients. 
  • Stem cell research Stem cell research is examining adult and human embryo cells in an attempt to discover how organs are developed and what stimulates their growth.

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