首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Two techniques have recently been developed to simplify research and reduce the number of nonhuman primates needed in studies of
Two techniques have recently been developed to simplify research and reduce the number of nonhuman primates needed in studies of
admin
2013-01-25
70
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 cells and the cells of certain human turnouts. In the other, animal oviduct tissue is transplanted under the skin of laboratory primates. Both culturing techniques complement existing methods of studying intact animals.
With an in vitro culturing technique, researchers are deciphering how biochemical agents regulate the secretion of prolactin, the pituitary hormone that promotes milk production. The cultured cells survive for as long as a month, and they do not require serum, 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 forms that shrinks and swells in tandem with stages of the menstrual cycle. With about 80 percent of the grafts re-establishing 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 anaesthesia, 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 infections, a leading cause of infertility among women. By infecting oviduct tissues transplanted into the abdominal skin of rhesus monkeys, researchers hope to determine how the bacteria cause pelvic inflammatory disease and lesions 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.
All of the following are true of the transplantation technique EXCEPT ______.
选项
A、It avoids the need for subjecting a laboratory subject to repeated major surgery
B、It permits scientists to monitor changes frequently
C、The transplanted cells grow as they would in their normal site
D、The transplanted cells can be easily grown in vitro
答案
D
解析
移植细胞很容易在试管中生长。第三段提到了A,B和C,没有提到 D。
转载请注明原文地址:https://kaotiyun.com/show/nL1O777K
0
考博英语
相关试题推荐
Overthepastfewyears,outcriesfromfoodactivistshavechangedmanyAmericans’eatinghabits:Criticismofwidespreadpestici
Thefridgeisconsideredanecessity.Ithasbeensosincethe1960swhenpackagedfoodfirstappearedwiththelabel:"storein
Ropepossessestheattributesofflexibilityand,perunitofweight,uncommonlygreatstrength.
The________ofthewordisunknown,butitiscertainlynotfromGreek.
Sometimesthestudentmaybeaskedtowriteabouthis____toacertainbookorarticlethathassomebearingonthesubjectbeing
ThemilitaryaspectoftheUnitedStatesCivilWarhasalwaysattractedthemostattentionfromscholars.Theroarofgunfire,
Researcherswhorefusetosharedatawithothersmay【51】otherstowithholdresultsfromthem,【52】astudybyhealth-policyanalys
Inancienttimes,somecatastrophicextinctionofspeciesoccurred______,butsuchcatastropheswerecomparativelyrare.
TheagreementisoverseenbytheCommitteeonAgriculturewhichreviewsprogressintheimplementationofcommitments,andisre
TheagreementisoverseenbytheCommitteeonAgriculturewhichreviewsprogressintheimplementationofcommitments,andisre
随机试题
课程计划、课程标准和教材均属于课程内容的文本表现形式,三者是并列的关系。
适合荧光分析法测定的无机离子()。
下列不属于货物进出口主要环节管理立法的是
男性,40岁,1周来发热,伴乏力;食欲很差,恶心,厌油,呕吐2次,近3天来尿黄。检查:体温已不高,皮肤巩膜中度黄染,肝肋下1.5cm,质软有触痛,脾未及,ALT15001U/L,TBil120μmol/L,DBil65μmol/L,AFP<25μg
2岁小儿,咳嗽3天,体温38℃,双肺有干性及不固定湿哕音,其诊断应首先考虑是
城市房屋拆迁过程中,拆迁人对被拆迁的()应依法予以补偿。[2004年考试真题]
(操作员:苏会计;账套:201账套;操作日期:2015年1月31日)1月8日,办公室杨颖用现金购买办公用品5500元,请填制记账凭证。
房地产开发项目质量管理应遵循()。
根据我国的法律效力层次,下列法律中效力最高的是()。
根据以下材料,回答下列小题。2010年全国废水排放总量617.3亿吨,比上年增加4.7%。其中,工业废水排放量237.5亿吨,比上年增加1.3%。城镇生活污水排放量379.8亿吨,比上年增加6.9%。废水中化学需氧量(COD)排放量1238.1万
最新回复
(
0
)