VOA标准英语2013--Children at Risk Despite Malaria Treatment

 

Children at Risk Despite Malaria¹ Treatment

Repeated bouts² of malaria may leave children vulnerable to other deadly infections and even cardiovascular disease later in life. Now, a new study may explain why.

About 200 children in Blantyre, Malawi, took part in the study. It compares kids in one group, who have mild or the more serious cerebral³ malaria, to those in another group, who are healthy. Malaria is caused by the bite of an infected mosquito that transmits parasites⁵ first to the liver and then to red blood cells. Tests showed the blood vessels⁷ of the two groups of children were different – especially those with cerebral malaria.

It has to do with inflammation. It’s long been known that diseases that cause acute fevers – febrile diseases – trigger inflammation in the endothelium. That’s the smooth, thin layer of cells lining⁸ blood vessels throughout the body.

“What people hadn’t looked at was whether that resolves after you give treatment and after the fact that the febrile illness goes away,” said Dr. Chris Moxon.

Moxon is the lead author of the study and a clinical lecturer at Liverpool University. At the time of the study he was a PhD Fellow at Wellcome Trust. He says when healthy, the endothelium allows the blood to flow unrestricted, similar to Teflon coating on a non-stick cooking pan.

“We were just thinking that the burden of malaria is extremely high in Africa – in the sort of level that’s very difficult for people who haven’t lived in a malaria endemic country to understand. Children are getting sometimes, in highly endemic areas, more than one infective bite a day and many repeated infections. And we just wondered what that might do to children and their endothelium in the long term,” he said.

Moxon and his colleagues knew that mosquito control programs appeared to have effects far beyond reducing malaria cases.

He said, “There have been a number of studies that have shown in small areas if you reduce or eliminate malaria that the reduction in mortality is higher than you might expect from simply a reduction in the number of acute febrile illnesses. So we wondered whether there was another effect that malaria was having. Whether this might be that the endothelium remained activated⁹ for a longer period of time.”

By an activated endothelium, he means inflamed¹⁰. There are blood tests to determine if that’s the case.

“The endothelial cells have proteins on the surface that give the endothelial cells a lot of their function. And these proteins are shed in healthy individuals, but when you get an illness and the endothelium changes they’re shed at higher levels. So you can measure these proteins in the blood and malaria changes the blood vessels. It sort of hijacks¹¹ the endothelium to be able to stick to blood vessels. And that’s a sort of mechanism¹² that the parasite⁴ uses to prevent going through the spleen and stop being cleared by our immune system,” he said.

So, if the endothelium is activated or inflamed, how does that predispose a child to other infections and possible future cardiovascular disease?

Moxon said, “If the endothelium is activated it may become more permeable. So it may become more leaky. For example, that may allow viruses or bacteria to leak and invade areas, for example, in the gut¹³. And then cardiovascular disease, those processes of inflammation make the endothelium more leaky to allow fat to accumulate inside the blood vessel⁶ wall.”

There’s been greater awareness¹⁴ in recent years of inflammation’s role in a host of diseases. While more study is needed, Moxon says controlling inflammation may help in preventing other infections following bouts with malaria -- and in turn reduce child mortality. He says statins – drugs used to lower cholesterol¹⁵ – may be one possibility. The drugs have been shown to help reduce inflammation.

1 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

2 bouts   

n.拳击（或摔跤）比赛( bout的名词复数 )；一段（工作）；（尤指坏事的）一通；（疾病的）发作

参考例句：

• For much of his life he suffered from recurrent bouts of depression. 他的大半辈子反复发作抑郁症。 来自《简明英汉词典》
• It was one of fistiana's most famous championship bouts. 这是拳击界最有名的冠军赛之一。 来自《现代英汉综合大词典》

3 cerebral   

adj.脑的，大脑的；有智力的，理智型的

参考例句：

• Your left cerebral hemisphere controls the right-hand side of your body.你的左半脑控制身体的右半身。
• He is a precise,methodical,cerebral man who carefully chooses his words.他是一个一丝不苟、有条理和理智的人，措辞谨慎。

4 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

5 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

6 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

7 vessels   

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》

8 lining   

n.衬里，衬料

参考例句：

• The lining of my coat is torn.我的外套衬里破了。
• Moss makes an attractive lining to wire baskets.用苔藓垫在铁丝篮里很漂亮。

9 activated   

adj. 激活的 动词activate的过去式和过去分词

参考例句：

• The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。

10 inflamed   

adj.发炎的，红肿的v.（使）变红，发怒，过热( inflame的过去式和过去分词 )

参考例句：

• His comments have inflamed teachers all over the country. 他的评论激怒了全国教师。
• Her joints are severely inflamed. 她的关节严重发炎。 来自《简明英汉词典》

11 hijacks   

劫持( hijack的名词复数 )； 绑架； 拦路抢劫； 操纵（会议等，以推销自己的意图）

参考例句：

• Just as life infiltrates matter mercilessly and then hijacks it forever, cultural life hijacks biology. 正如生命无情地浸入物质并永远地将其劫持，文化生命也劫持了生物界。

12 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

13 gut   

n.[pl.]胆量；内脏；adj.本能的；vt.取出内脏

参考例句：

• It is not always necessary to gut the fish prior to freezing.冷冻鱼之前并不总是需要先把内脏掏空。
• My immediate gut feeling was to refuse.我本能的直接反应是拒绝。

14 awareness   

n.意识，觉悟，懂事，明智

参考例句：

• There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
• Environmental awareness has increased over the years.这些年来人们的环境意识增强了。

15 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。