HEALTH REPORT - Prion Diseases

HEALTH REPORT - Prion Diseases
By Nancy Steinbach

Broadcast: Wednesday, January 21, 2004

This is the VOA Special English Health Report.

In December, the United States reported its first case of mad cow disease. Agriculture officials have been working to make sure other cows that came from Canada with that animal are not used as food. This is because of the possibility that people who eat infected beef can get a human form of the disease. Officials say more than one-hundred-forty people in Britain have died since an outbreak of mad cow disease in the nineteen-eighties. Ten deaths have been reported in other countries.

The scientific name of the cattle disease is bovine¹ spongiform encephalopathy. A similar disease in sheep is known as scrapie. Deer and elk² suffer chronic³ wasting disease. And minks⁵ get a disease called transmissable mink⁴ encephalopathy.

In humans, there is a disease in babies called Alpers syndrome⁶. Other similar diseases in people include fatal familial insomnia⁷, kuru and Creutzfeld-Jacob disease. The human version of mad cow disease is a form, or variant⁸, of Creutzfeld-Jacob.

 
A picture of a Prion.
All these diseases create holes in the brain. All kill. And experts say all are caused by infectious proteins. American scientist Stanley Prusiner discovered this kind of protein in the early nineteen-eighties. He named it a "prion" [PREE-on]. He won the Nobel Prize for Medicine. Prions contain no genetic⁹ material. So they cannot copy themselves the way bacteria, viruses and other infectious agents do.

Prions are found naturally in brain cells of people and animals. Research published last month in Cell magazine suggested that prions could help the brain store memories. But experts are not sure of their purpose.

Prions appear to do no harm until one changes shape. Normally a prion is round like a ball. The protein becomes dangerous when it unfolds into a straight line. When it touches another prion, the second one unfolds and touches another. That one also unfolds, and so on.

This process can start naturally. Or it can begin when an unfolded prion enters the brain of a person or animal that has eaten infected tissue. This is why farmers are now banned from feeding cows the remains¹⁰ of other cows and sheep.

Researchers are trying to discover more about prions. A big question is why only some people who ate infected beef have gotten sick.

This VOA Special English Health Report was written by Nancy Steinbach.

1 bovine   

adj.牛的；n.牛

参考例句：

• He threw off his pack and went into the rush-grass andand munching,like some bovine creature.他丢开包袱，爬到灯心草丛里，像牛似的大咬大嚼起来。
• He was a gentle,rather bovine man.他是一位文雅而反应迟钝的人。

2 elk   

n.麋鹿

参考例句：

• I was close enough to the elk to hear its labored breathing.我离那头麋鹿非常近，能听见它吃力的呼吸声。
• The refuge contains the largest wintering population of elk in the world.这座庇护所有着世界上数量最大的冬季麋鹿群。

3 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

4 mink   

n.貂，貂皮

参考例句：

• She was wearing a blue dress and a mink coat.她穿着一身蓝色的套装和一件貂皮大衣。
• He started a mink ranch and made a fortune in five years. 他开了个水貂养殖场，五年之内就赚了不少钱。

5 minks   

n.水貂( mink的名词复数 )；水貂皮

参考例句：

• Fuck like minks, forget the rug rats, and live happily ever after. 我们象水貂一样作爱，忘掉小水貂吧，然后一起幸福生活。 来自互联网
• They fuck like minks, raise rug rats, and live happily ever after. 他们象水貂一样做爱，再养一堆小水貂，然后一起幸福的生活。 来自互联网

6 syndrome   

n.综合病症；并存特性

参考例句：

• The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
• Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。

7 insomnia   

n.失眠，失眠症

参考例句：

• Worries and tenseness can lead to insomnia.忧虑和紧张会导致失眠。
• He is suffering from insomnia.他患失眠症。

8 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

9 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

10 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。