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
Some scientists have concluded that narcolepsy, a disease which disrupts sleep patterns, arises when unknown agents in th
Some scientists have concluded that narcolepsy, a disease which disrupts sleep patterns, arises when unknown agents in th
admin
2011-01-17
45
问题
Some scientists have concluded that narcolepsy, a disease which disrupts
sleep patterns, arises when unknown agents in the environment spur an
autoimmune reaction winding up damaging neurons in the brain circuits that Line
control arousal and muscle tone. Honda found that all members of a group of
(5) narcoleptics had one aspect of their tissue type in common, one of the human
leukocyte antigens (HLAs). Whereas the HLA type was clearly not sufficient to
induce narcolepsy, Honda’s finding indicated that HLA type greatly affected
susceptibility to the disease. HLA molecules are pitchfork-shaped structures that
cells of the body use to show pieces of the proteins they contain to the immune
(10) system, which ordinarily attacks foreign substances and cells infected by
viruses.
Evidence for an autoimmune cause of narcolepsy will most likely come from
studies of the brains of people who had the disorder. Ever since Gineau
correctly named narcolepsy as a distinct syndrome in 1880, researchers have
(15) examined the brains of patients in a futile search for neurological damage that
could explain the symptoms of the disease. Mignot observed that the brains of
narcoleptic dogs had more than the usual number of receptors for the
neurotransmitters acetylcholine, dopamine and norepinephrine and higher levels
of some of the neurotransmitters themselves, changes identical to those Aldrich
(20) later noted human narcoleptic brains.
Given that narcolepsy is not progressive but chronic—i.e. after the
establishment of symptoms, narcoleptics do not deteriorate or improve-
pathologists may have been focusing their efforts on the wrong stage of the
disease’s progression. This suggested that the damage might occur during a
(25) short time, roughly during the period in which a patient first develops signs of
the illness. Debris left over from degenerative processes that occurred at the
age of 20 would be removed by the brain’s support cells long before most
patients died, and any remaining clues would be obscured by the normal
degeneration of aging. As a loss of neurons would be undetectable unless the
(30) dead cells were concentrated in a particular area, as in Parkinson’s disease, or
unless many neurons died, as in Alzheimer’s disease, I therefore examined the
brains of narcoleptic dogs shortly after their symptoms had begun, and found
clear evidence that neurons in certain areas of the dogs’ brains were
degenerating between one and two months of age, just before and during the
(35) onset of symptoms. Evidence of the degeneration largely disappeared by the
time the dogs were six months old. At this moment, all we can give patients are
drugs to treat narcolepsy’s symptoms, even though this research promises the
definite potential of a cure.
The passage supplies information to answer which of the following questions?
选项
A、Which species, human or dog, has greater numbers of the neurotransmitters that have been hypothetically linked to narcolepsy?
B、At what age do human beings first experience the degenerative effects of narcolepsy?
C、What role do human leukocyte antigens perform for the human immune system?
D、Why did Honda initially suspect that HLAs played a role in narcolepsy?
E、Which of the researchers named in the passage isolated narcolepsy as a distinct syndrome?
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/rhjO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
Accordingtosociologists,thereareseveraldifferentwaysinwhichapersonmaybecomerecognizedastheleaderofasocialgr
Halfoftheworld’scoralreefs(珊瑚礁)havediedinthelast30years.Nowscientistsareracingtoensurethattherestsurvive
Usingextremelydifferentdecoratingschemesinadjoiningroomsmayresultin______andlackofunityinstyle.
Anengineerdesignedaballsothatwhenitwasdropped,itrosewitheachbounceexactlyone-halfashighasithadfallen.The
Sixdifferentnumbersaretobeselectedfromthe(0,1,2,3,4,5,6)tocomposea6-digitevennumberthatisgreaterthan300
Proteinsynthesisbeginswhenthegeneencodingaproteinisactivated.Thegene’ssequenceofnucleotidesistranscribedinto
ExperiencedgardenersadviseagainstplantingsnappeasafterlateAprilbecausepeasdonotdevelopproperlyinwarmweather.T
MarissauseswhichofthefollowingtechniquesinattemptingtorefuteWalter’sargument?
Radiointerferometryisatechniqueforstudyingdetailsofcelestialobjectsthatcombinessignalsinterceptedbywidelyspaced
CompletethesummarybelowwithwordstakenfromReadingPassage2.UseNOMORETHANTWOWORDSforeachanswer.Writeyo
随机试题
下列常识表述中,正确的是:
病原体侵入血流,在血中繁殖产生毒素,表现严重的中毒症状,诊断为:()
男,30岁,输精管结扎术后2天,手术切口部位疼痛、红肿、有脓性分泌物,最可能的诊断是
某患者,因外伤急性失血,血压降至60/40mmHg,尿量明显减少,其尿量减少的原因主要是
下列语句中没有语病的一句为()。
2005年1月1日,甲公司以105000元的价格(包括交易费用5000元)购入乙公司面值为100000元、3年期、10%利率的公司债券,准备持有至到期,则甲公司应计入此项投资的初始投资成本为()元。
社会主义初级阶段的不可逾越性主要是由()。
下列各种内存管理方案中,哪些可以与虚拟存储技术结合使用?()
A、Changethetopicofherresearchproject.B、Signupforadifferentpoliticalsciencecourse.C、AskMarytohelpherchoosea
A、Makeacopyofhisnotes.B、Askherprofessorforhelp.C、Attendthereviewsessions.D、Gotothechemistrylabthisevening.
最新回复
(
0
)