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
The prospects for treating cystic fibrosis by gene therapy are looking brighter following successful tests with a safer type of
The prospects for treating cystic fibrosis by gene therapy are looking brighter following successful tests with a safer type of
admin
2011-01-06
98
问题
The prospects for treating cystic fibrosis by gene therapy are looking brighter following successful tests with a safer type of "shuttle"(短程梭运输工具)for ferrying(运送) replacement genes into a patient’s lungs. During the tests, a British-led research team inserted healthy copies of the cystic fibrosis(囊性纤维变性) gene into cells lining sufferers’ noses with the aid of microscopic droplets(水滴,飞沫) of fat called liposome
Other groups that have attempted to correct the genetic defect that causes cystic fibrosis have used viruses as "vectors" (媒介) to carry the healthy gene into target cells. Unfortunately, viruses can also cause inflammation in the lungs, an undesirable side effect in CF patients, whose lungs are already diseased. The new method for introducing corrective genes into the lungs of CF patients promises to be much safer.
Cystic fibrosis is caused by defects in a gene called CFTR, which plays a part in the transport of chloride ions(离子) out of the cells lining the lungs, airways and gut. Defects in this gene mean that patients have difficulty expelling mucus(黏液) and inhaled (吸入) microorganisms from their lungs. As a result, they are very susceptible to lung infections, and usually die at around 30 years old.
As an alternative to the viral vector, the researchers, linked loops (环)of DNA containing healthy copied of the CFTR gene to microscopic liposomes. When the liposomes come in contact with a cell, they fuse(融合) with its outer membrane, and release the DNA into the cell’s interior. To test the system, the team sprayed the liposomes into the noses of volunteers with cystic fibrosis. "The cells lining the nose are very similar to those lining the lung," explains David Porteous of the human genetics group in Edinburgh. But the ceils in the nose are easier to monitor, and the risks are lower if any nasal (鼻的)cells are damaged.
In the event(结果,到头来), none of the volunteers suffered any unpleasant side effects. And a single spraying partially corrected the cystic fibrosis defect. The researchers assessed the effectiveness of the treatment by measuring the voltage(电压,伏特) across the layer of cells lining the nose. This voltage is higher in cystic fibrosis sufferers than in healthy people. A single spraying reduced this difference by around 20 per cent. The re-searchers reported that the effect lasted for up to a week.
The British researchers have yet to test their spray in the lungs, but are confident that the liposomes will not cause inflammation. The question, however, is how effective the shuttle system is. In the nose, the researchers had to add more copies of the healthy CFTR gene to match the performance of the adenovirus. This is because adenoviruses carry genes directly to the cell’ s nucleus, ensuring that the instructions they carry are read. Genes carried by liposomes are only guaranteed a ride into the cell’s cytoplasm, and fewer will find their way to the nucleus. Many will be broken down by the cell’s waste disposal system before they get there.
Bob Williamson, who heads the group at St. Mary’s Hospital, says this will require much more efficient vectors. "People in 10 to 15 years will laugh at the crudity of the liposomes and viruses that we’re using today, " he says. The aim is to make customized vectors which combine the best aspects of both systems, and include other genetic sequences to ensure that the information carried by the healthy CFTR gene is used by the target cells lining the lungs.
The researchers have tested their spray in the lungs.
选项
A、Right
B、Wrong
C、Not mentioned
答案
B
解析
见第六段,“The British researchers have yet to test their spray in the lungs.”英国研究人员仍然要做试验将喷雾用在肺上。
转载请注明原文地址:https://kaotiyun.com/show/Zzmd777K
本试题收录于:
职称英语卫生类B级题库职称英语分类
0
职称英语卫生类B级
职称英语
相关试题推荐
Whatwillitmeantoknowthecompletehumangenome.EricLanderofMIT’sWhiteheadInstitutecomparesittothediscoveryofth
1.WhenChristopherColumbusLandonAmerica’sshores,heencounteredcopper-shinnedpeoplewhomhepromptlycalled"Indians".C
Itisnaturalforyoungpeopletobecriticaloftheirparentsattimesandtoblamethemforthemostofthemisunderstandings
Readthefollowingarticleandchoosethebestwordforeachspace.Forquestions26-45,markoneletterA,B,CorDonyou
Lookatthequestionsforthispart.Forquestions24-30,indicatewhichofthealternativesA,B,orCisthemostappropri
Somespeciesofbirdsarehighlysociableandnestindensecolonies.
A.ConfirmationoftheNewEffectB.Pain-relievingandFever-reducingEffectsofAspirinC.TheIgnoredSignificantObservation
Reliefworkerswereshockedbywhattheysaw.
Theeconomywillmaintainitshighgrowthlevelsandthegovernmentstillhasplentyofroomtofurthertightenmonetarypolicy.
RecentdiscoveriesinMontanaindicatethatsomedinosaursmayhaveresidedincolonies.
随机试题
下列哪一或哪些选项的表述可以成立?()
喷涂时在喷枪内至少存在()气。
标定高锰酸钾标准滴定溶液的基准物质有()。
企业总分类会计科目设置的基础是
事物阴阳属性错误表述的一项是
关于流行性脑脊髓膜炎的叙述,错误的是
反佐药的作用包括
关于地铁车站留置施工缝位置说法,正确的有()。
下列情形中,纳税人应进行土地增值税清算的是()。
中国近代史是一部屈辱史,又是一部抗争史。先进的中国人为了寻求救国救民的真理,不断向西方学习,开始了中国的近代化。为中国的近代化开辟了道路的历史事件是()。
最新回复
(
0
)