艾滋病毒扰乱血脑屏障
文章来源:未知 文章作者:enread 发布时间:2011-06-29 02:42 字体: [ ]  进入论坛
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HIV weakens the blood-brain barrier — a network of blood vessels1 that keeps potentially harmful chemicals and toxins3 out of the brain — by overtaking a small group of supporting brain cells, according to a new study in the June 29 issue of The Journal of Neuroscience. The findings may help explain why some people living with HIV experience neurological complications, despite the benefits of modern drug regimens that keep them living longer. Standard antiretroviral(抗逆转录病毒的) treatments successfully suppress the replication of HIV and slow the progression of the disease. Yet recent studies show 40 to 60 percent of patients on such therapy continue to experience mild to moderate neurological deficits4 — including memory loss and learning challenges.

In the new study, Eliseo Eugenin, PhD, of Albert Einstein College of Medicine, found that HIV infection in a small number of supporting brain cells called astrocytes(胶细胞) breaks down the blood-brain barrier, despite low to undetectable viral production. Under normal conditions astrocytes help bolster5 the blood vessels comprising the barrier.

To test if HIV interfered6 with this support system, Eugenin and his colleagues built a model of the blood-brain barrier using human cells in the laboratory. In a previous study, the researchers found HIV infects around 5 percent of astrocytes. In the current study, the researchers found the presence of HIV in a similar percentage of astrocytes led to the death of nearby uninfected cells and made the barrier more permeable(可渗透的) .

As the neighboring cells died, however, HIV-infected astrocytes survived. Astrocytes exchange chemical signals through specialized7 molecules8 called gap junctions9. When they were blocked in the model, it prevented the changes to the blood-brain barrier and nearby cells, suggesting the infected astrocytes relay toxic10 signals to neighboring cells through the gap junctions.

"Our results suggest HIV infection of astrocytes may be important in the onset11 of cognitive12 impairment in people living with the disease," Eugenin said. "New therapies are needed that not only target the virus, but also to stop the virus from spreading damage to other uninfected brain cells."

Eugenin's group also analyzed13 the brain tissue of macaque(猕猴,恒河猴) monkeys infected with the simian14 form of HIV. Similar to what they saw in the human blood-brain barrier model, the researchers found uninfected cells in contact with HIV-infected astrocytes died, while infected astrocytes remained alive as the disease progressed.

"Researchers have been stymied15 to explain why HIV-associated neurological complications persist, despite potent2 combination antiviral therapies that have dramatically improved health and survival," said Igor Grant, an expert who studies HIV-associated neurocognitive impairment at the University of California, San Diego. "This study provides a possible explanation indicating that minute numbers of infected astrocytes can trigger a cascade16(层叠,小瀑布) of signals that could open the brain to various toxic influences."

The findings open up the possibility of developing new therapeutic17 approaches that block or modify the transmission of signals from the HIV-infected astrocytes, added Grant, who was not affiliated18 with the study.



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1 vessels fc9307c2593b522954eadb3ee6c57480     
n.血管( vessel的名词复数 );船;容器;(具有特殊品质或接受特殊品质的)人
参考例句:
  • The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
  • All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》
2 potent C1uzk     
adj.强有力的,有权势的;有效力的
参考例句:
  • The medicine had a potent effect on your disease.这药物对你的病疗效很大。
  • We must account of his potent influence.我们必须考虑他的强有力的影响。
3 toxins 18c3f40d432ba8dc33bad8fb82873ea8     
n.毒素( toxin的名词复数 )
参考例句:
  • The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
  • Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》
4 deficits 08e04c986818dbc337627eabec5b794e     
n.不足额( deficit的名词复数 );赤字;亏空;亏损
参考例句:
  • The Ministry of Finance consistently overestimated its budget deficits. 财政部一贯高估预算赤字。 来自《简明英汉词典》
  • Many of the world's farmers are also incurring economic deficits. 世界上许多农民还在遭受经济上的亏损。 来自辞典例句
5 bolster ltOzK     
n.枕垫;v.支持,鼓励
参考例句:
  • The high interest rates helped to bolster up the economy.高利率使经济更稳健。
  • He tried to bolster up their morale.他尽力鼓舞他们的士气。
6 interfered 71b7e795becf1adbddfab2cd6c5f0cff     
v.干预( interfere的过去式和过去分词 );调停;妨碍;干涉
参考例句:
  • Complete absorption in sports interfered with his studies. 专注于运动妨碍了他的学业。 来自《简明英汉词典》
  • I am not going to be interfered with. 我不想别人干扰我的事情。 来自《简明英汉词典》
7 specialized Chuzwe     
adj.专门的,专业化的
参考例句:
  • There are many specialized agencies in the United Nations.联合国有许多专门机构。
  • These tools are very specialized.这些是专用工具。
8 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句:
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
9 junctions 8d6818d120fa2726af259fc9dc6c7c61     
联结点( junction的名词复数 ); 会合点; (公路或铁路的)交叉路口; (电缆等的)主结点
参考例句:
  • Metals which were mutually soluble would tend to give strong junctions. 可互溶的金属趋向于产生牢固的结合点。
  • Some adhering junctions are present as narrow bands connecting two cells. 有些粘附连接以一窄带的形式连接两个细胞。
10 toxic inSwc     
adj.有毒的,因中毒引起的
参考例句:
  • The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
11 onset bICxF     
n.进攻,袭击,开始,突然开始
参考例句:
  • The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
  • Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。
12 cognitive Uqwz0     
adj.认知的,认识的,有感知的
参考例句:
  • As children grow older,their cognitive processes become sharper.孩子们越长越大,他们的认知过程变得更为敏锐。
  • The cognitive psychologist is like the tinker who wants to know how a clock works.认知心理学者倒很像一个需要通晓钟表如何运转的钟表修理匠。
13 analyzed 483f1acae53789fbee273a644fdcda80     
v.分析( analyze的过去式和过去分词 );分解;解释;对…进行心理分析
参考例句:
  • The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
  • The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程,因为对他来说,爱是个不可分析的迷。 来自《简明英汉词典》
14 simian 2ENyA     
adj.似猿猴的;n.类人猿,猴
参考例句:
  • Ada had a wrinkled,simian face.埃达有一张布满皱纹、长得像猿猴的脸。
  • Curiosity is the taproot of an intellectual life,the most valuable of our simian traits.好奇是高智生命的根源,也是我们类人猿特征中最有价值的部分。
15 stymied 63fe672f90de7441b83f6a139c130d06     
n.被侵袭的v.妨碍,阻挠( stymie的过去式和过去分词 )
参考例句:
  • Relief efforts have been stymied in recent weeks by armed gunmen. 最近几周的救援工作一直受到武装分子的阻挠。 来自辞典例句
  • I was completely stymied by her refusal to help. 由于她拒不相助, 我完全陷入了困境。 来自互联网
16 cascade Erazm     
n.小瀑布,喷流;层叠;vi.成瀑布落下
参考例句:
  • She watched the magnificent waterfall cascade down the mountainside.她看着壮观的瀑布从山坡上倾泻而下。
  • Her hair fell over her shoulders in a cascade of curls.她的卷发像瀑布一样垂在肩上。
17 therapeutic sI8zL     
adj.治疗的,起治疗作用的;对身心健康有益的
参考例句:
  • Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
  • When I was sad,music had a therapeutic effect.我悲伤的时候,音乐有治疗效力。
18 affiliated 78057fb733c9c93ffbdc5f0ed15ef458     
adj. 附属的, 有关连的
参考例句:
  • The hospital is affiliated with the local university. 这家医院附属于当地大学。
  • All affiliated members can vote. 所有隶属成员都有投票权。
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