Gene Analytical — the Substitute Organize Examination A blood

游客2023-11-14  22

问题               Gene Analytical — the Substitute Organize Examination
    A blood test that analyzes genetic activity could let heart transplant patients avoid many of the invasive (有扩散危害的) and uncomfortable biopsies (活组织检查) now used to monitor whether their immune systems are rejecting their new organs.
    The study found that patients who were monitored for rejection using the blood test had outcomes roughly equivalent to those of patients who were given frequent heart biopsies. The test, called AlloMap, was developed by XDx.
    Still, the authors of the study acknowledged that the trial was too small and too brief to allow for firm conclusions. It also excluded very recent transplant recipients, who have the highest risk of rejection.
    Despite the use of immune-suppressing drugs, about one-quarter of heart transplant recipients have a rejection episode requiring treatment in the first year after the transplant. While such episodes can be treated by drugs, they may damage the heart, especially if the treatment is not started soon enough. In some cases the rejections prove fatal.
    Some transplant centers perform biopsies as often as once a week after the transplant, and as often as every few months for the next several years. A tube is inserted into a vein in the neck and threaded to the heart to pick up pieces of heart tissue to be examined under a microscope.
    Efforts have been made to develop less invasive approaches to detect rejection, including use of imaging, and the AlloMap test was approved for this use by the Food and Drug Administration in 2008.
    The study involved 602 patients at 13 American transplant centers who had received a transplant from six months to five years earlier. Half were given periodic biopsies and the others the blood test at the same frequency.
    The least expensive approach might be to conduct less testing of either type. Only 6 of the 34 episodes of rejection in the group getting the genetic test were found solely by the test. The rest were detected by echocardiogram (超声心动图) or because of symptoms.
    Dr. Jarcho, in his commentary, said those results raised the question of whether routine screening for rejection was even needed. Some transplant centers have already scaled back the number of biopsies they do. [br] Which of the following statements is TRUE according to the passage?

选项 A、The study collects enough evidence to reach a final conclusion.
B、Only a minority of heart transplant recipients don’t have a rejetion episode.
C、301 of the patients in the study received a transplant over six months.
D、Routine screening is not so necessary to detect rejection by doctors.

答案 D

解析 推理判断题。文章倒数第二段提到34例排斥反应中只有6例是通过检查发现的。最后一段用Dr.Jarcho的话做总结,提到:...those results raised the question of whether routine screening for rejection was even needed.说明Dr.Jarcho认为常规的筛选检查也许是不必要的。常规的筛选检查即上文提到的blood test以及biopsy。[A]与第三段第一句不符,文中提到实验规模较小,所以得不出确切的结论;[B]由第4段首句大约1/4的病人出现排斥反应推断出大多数病人不会出现排斥反应;[C]由倒数第三段首名有效期不能推断出。
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