Gene Analytical — the Substitute Organize Examination A blood

游客2023-11-14  21

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 is TRUE about the biopsies?

选项 A、It is usually carried out frequently after the transplant.
B、The piees of heart tissue are taken out from throat.
C、A tube is threaded to the heart by hand.
D、The examination is carried out by using magnifying glass.

答案 A

解析 事实细节题。文章第五段第一句提到: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.说明活组织检查是在进行移植以后有规律进行的。[B]、[C]、[D]与第五段第二句不符。活组织是通过从脖子插人血管的管子提取的,然后通过显微镜进行观察。
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