VOA慢速英语2015 沙门氏菌已转化为杀死癌细胞的超级战士

Salmonella Turned Into Cancer Killing¹ Super Bug² 沙门氏菌已转化为杀死癌细胞的超级战士

From VOA Learning English, this is the Health and Lifestyle Report.

Not many people consider a bacterium³ that makes millions of people sick … a friend. But scientist Roy Curtiss does.

"Yeah, I'm always looking for new uses for a bug that most people think is an enemy -- it's my friend. And I would like to make it your friend -too."

Roy Curtiss is a microbiologist at the Biodesign Institute at Arizona State University in Tempe, Arizona. He uses the word ‘bug,’ a common expression for a germ or virus, when talking about Salmonella bacteria.

Mr. Curtiss studies Salmonella and thinks it “gets a bad rap.” In other words, many people only have bad thoughts when they hear the word, “Salmonella.”

What is Salmonella?

Salmonella is the most common bacteria to harm, or contaminate, food. It is found in undercooked meats, eggs and milk. Salmonella can cause a higher than normal body temperature and pain in the abdomen⁴. The person may feel sick, throwing up whatever is in the stomach.

One form of Salmonella is also responsible for the disease typhoid.

So, it is only natural that a bacterium that makes people sick is given a bad rap. The question is, “When does a food-borne bacterium become your friend?” The answer: when it helps to kill cancer cells.

"The enemy of my enemy is my friend."

Millions of people are sickened each year by Salmonella. But a genetically⁶-engineered version of the bacteria may someday be used as a weapon against cancer. As the old saying goes, “The enemy of my enemy is my friend.”

Researchers in the United States and Germany have turned Salmonella into a weapon against cancerous tumors. Roy Curtiss says the bacteria can make the cancer cells disappear.

The experiment

And here is the experiment. First, the researchers changed the genes⁸ of the Salmonella to die in healthy tissues but kill cancer cells. They put human cancer cells into mice. Then, he says, they put the genetically-modified Salmonella bacteria into the animals.

"We genetically modify the Salmonella so that it is unable to survive in healthy tissues, but has a preferential homing (attraction) to tumors, which [are] a very nutrient-rich environment where they grow like crazy and, in so doing, kill the cancer cells within the tumor⁷."

A report describing the work was published in the medical journal mBio.

Roy Curtiss says it will be a while before the genetically-modified version of Salmonella is tested on human beings. He wants to make more changes to the bacteria to increase their cancer-killing power.

Salmonella would not be a stand-alone treatment for fighting cancer. Instead, Mr. Curtiss hopes the genetically-modified bacteria will be used in addition to more traditional therapies, such as chemotherapy and radiation.  

Words in This Story

bad rap – idiomatic⁹ expression a negative and often undeserved reputation —often used with bum¹⁰ or bad (Example: He got a bad (or bum) rap by the press.)

borne – adj. carried by : spread by — used in combination as in “waterborne” and “airborne”

genetically-modified - adjective containing genetic⁵ material that has been artificially altered so as to produce a desired effect

tumor – n. a mass of tissue found in or on the body that is made up of abnormal cells

contaminate – v. to make (something) dangerous, dirty, or impure¹¹ by adding something harmful

chemotherapy – n. medical the use of chemicals to treat or control a disease (such as cancer)

radiation – n. medical the use of controlled amounts of radiation for the treatment of diseases (such as cancer)

1 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

2 bug   

n.虫子；故障；窃听器；vt.纠缠；装窃听器

参考例句：

• There is a bug in the system.系统出了故障。
• The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。

3 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

4 abdomen   

n.腹，下腹(胸部到腿部的部分)

参考例句：

• How to know to there is ascarid inside abdomen?怎样知道肚子里面有蛔虫？
• He was anxious about an off-and-on pain the abdomen.他因时隐时现的腹痛而焦虑。

5 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。

6 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

7 tumor   

n.（肿）瘤，肿块(英)tumour

参考例句：

• He was died of a malignant tumor.他死于恶性肿瘤。
• The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。

8 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

9 idiomatic   

adj.成语的，符合语言习惯的

参考例句：

• In our reading we should always be alert for idiomatic expressions.我们在阅读过程中应经常注意惯用法。
• In his lecture,he bore down on the importance of idiomatic usage in a language.他在演讲中着重强调了语言中习惯用法的重要性。

10 bum   

n.臀部；流浪汉，乞丐；vt.乞求，乞讨

参考例句：

• A man pinched her bum on the train so she hit him.在火车上有人捏她屁股，她打了那人。
• The penniless man had to bum a ride home.那个身无分文的人只好乞求搭车回家。

11 impure   

adj.不纯净的，不洁的；不道德的，下流的

参考例句：

• The air of a big city is often impure.大城市的空气往往是污浊的。
• Impure drinking water is a cause of disease.不洁的饮用水是引发疾病的一个原因。