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
68
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.
It may be inferred from the passage that by studying the brains of narcoleptic dogs, the author learned that
选项
A、neural degeneration may occur too early for scientists to be able draw many useful conclusions about it
B、a loss of neurons would be undetectable unless the dead cells were concentrated in a particular area of the brain
C、pathologists not only were researching the wrong stage of the disease process, but ignoring its unique effects on different species
D、the brain tends through its natural processing to remove the effects of neural degeneration
E、the theories of Aldrich and Mignot were largely correct, at least as far as dogs are concerned
答案
A
解析
转载请注明原文地址:https://www.kaotiyun.com/show/uhjO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
Halfoftheworld’scoralreefs(珊瑚礁)havediedinthelast30years.Nowscientistsareracingtoensurethattherestsurvive
Itwasconsideredimpolitebymanytodiscussbusinessonsocial______.
Dina:Youlookrun-down,Brian.Brian:Yeah.I’vebeenfeelingundertheweatherrecently.【D8】______andIstillhaven’tgot
Thenumbers3,10,17,24,31and38arethefirstsixtermsofaninfinitesequenceinwhicheachtermafterfirstis7greater
Proteinsynthesisbeginswhenthegeneencodingaproteinisactivated.Thegene’ssequenceofnucleotidesistranscribedinto
Proteinsynthesisbeginswhenthegeneencodingaproteinisactivated.Thegene’ssequenceofnucleotidesistranscribedinto
ExperiencedgardenersadviseagainstplantingsnappeasafterlateAprilbecausepeasdonotdevelopproperlyinwarmweather.T
DECOROUS:PROPRIETY::
Althoughcondemnedbythereviewpanel,tofilmcriticPaulineKaelthemovieseemedentirely______andunlikelytooffend.
CompletethesummarybelowwithwordstakenfromReadingPassage2.UseNOMORETHANTWOWORDSforeachanswer.Writeyo
随机试题
客车在行驶中遇险时,驾驶人要怎么做?
在一棵完全二叉树的顺序存储方式中,若编号为t的结点有右孩子,则此结点右孩子的编号为()
(2007年4月)简述企业组织结构设计的原则。
患者,女,31岁。初产后3周出现乳房局部结块,局部红肿热痛,并有恶寒发热等症状,应诊为
经行吐衄的发病机制主要是
患者,女,36岁。G3P0,自然流产2次,现妊娠30周。产前检查发现宫高24cm,腹围85cm,均小于相应孕周,以胎儿生长受限收入院进一步诊治。下列与胎儿生长受限无关的因素是
对于电池的符号为:(-)Pt|Sn4+,Sn2+||Fe3+,Fe2+|Pt(+),则此电池反应的产物为()。
会计的基本职能是()。
与单一法人客户相比,集团法人客户的信用风险具有的特征不包括()。
大李夫妇有一个15岁的孩子,一直以来,孩子的大小事情都由父母安排。最近一年,他们发现孩子脾气越来越坏,不服父母的管教,事事要自己做主,有时还与父亲发生激烈争吵。从家庭生命周期的角度来看,该家庭目前最重要的任务是()。
最新回复
(
0
)