2. 职称英语
  3. Two techniques have recently been developed to simplify research and reduce t

Two techniques have recently been developed to simplify research and reduce t

游客2025-01-05  18
问题    Two techniques have recently been developed to simplify research and reduce the number of nonhuman primates needed in studies of certain complex hormonal reactions. One technique involves the culturing of primate pituitary(垂体)cells and the cells of certain human tumors. In the other, animal oviduct (输卵管) tissue is transplanted under the skin of laboratory primates. Both culturing techniques complement existing methods of studying intact(完整的) animals.
   With an in vitro culturing technique, researchers are deciphering how biochemical agents regulate the secretion of prolactin(催乳激素), the pituitary hormone that promotes milk production. The cultured cells survive for as long as a month, and they do not require serum (血清), a commonly used culture ingredient that can influence cellular function and confound study results. One primate pituitary gland may yield enough cells for as many as 72 culture dishes, which otherwise would require as many animals.
   The other technique allows scientists to monitor cellular differentiation in the reproductive tracts of female monkeys.  While falling short of the long-sought goal of developing an in vitro model of the female reproductive system, the next-best alternative was achieved. The method involves transplanting oviduct tissue to an easily accessible site under the skin, where the grafted cells behave exactly as if they were in their normal environment. In about 80 percent of the grafts, blood vessels in surrounding abdominal skin grow into and begin nourishing the oviduct tissue. Otherwise, the tissue is largely isolated, walled off by the surrounding skin. A cyst(囊胞) forms that shrinks and swells in tandem(一前一后的串联) with stages of the menstrual cycle. With about 80 percent of the grafts reestablishing themselves in the new site, a single monkey may bear as many as 20 miniature oviducts that are easily accessible for study.  Because samples are removed with a simple procedure requiring only local anesthesia, scientists can track changes in oviduct cells over short intervals. In contrast, repeated analysis of cellular changes within the oviduct itself would require abdominal surgery every time a sample was taken a procedure that the animals could not tolerate.
   Scientists are using the grafting technique to study Chlamydia (衣原体)infections, a leading cause of infertility among women. By infecting oviduct tissues transplanted into the abdominal skin of rhesus (罗猴)monkeys, researchers hope to determine how the bacteria cause pelvic inflammatory disease and lesions(损害)that obstruct the oviduct. Such research could eventually lead to the development of antibodies to the infectious agent and a strategy for producing a Chlamydia vaccine. [br] According to the passage, the primary benefit of the new research is that ______.
选项 A、scientists can study the pituitary gland for the first time
B、the procedures are simpler and require fewer laboratory animals
C、the study of intact laboratory animals has now been rendered obsolete
D、researchers were able to discover prolactin
答案 B
解析 细节题，任务就是将具体的内容从文章中找出来。尽管本文几次提及新技术的优点，但文中的第一句话就完整地概括了这个问题。B的内容正是对新技术优点的总结，它是对的。A是错的，因为文中没有提及这是first time科学家能够研究pituitary gland。C是错的。文中确实提到了新技术减少了动物的需要量，但并没有说实验性的动物没有必要了。D的错误与A一样，文章没有讲到新技术导致discovery of prolactin。
转载请注明原文地址:http://tihaiku.com/zcyy/3899468.html
相关试题推荐
随机试题
最新回复(0)