New Blood Test May 1)Detect Colon Cancer

Broadcast: Mar¹ 13, 2003

 

Researchers are developing a blood test to look for colon² cancer. The blood test is designed to detect ²⁾abnormalities in genes⁴ that control cell growth. These genes are passed on by both parents, and operate like switches, with only one switched on at a time. Under normal circumstances, only one gene³, or switch, is turned on, and the other is off.

But when both switches are stuck in the "on" position, it causes what experts say is a "loss of imprinting⁵," or instructions to the cells, and the result can be colon cancer. Experts think loss of imprinting triggers up to 40 percent of colon cancer cases.

Andrew Feinberg, a professor of medicine at Johns Hopkins University in Baltimore, Maryland, and the study's co-author, says researchers have already observed loss of imprinting in colon cancer cells.

In the current study, published this week in the journal Science, investigators⁶ took the blood samples of 170 people with some sort of history of colon cancer.

"What we are doing is examining their normal cells, and finding that this abnormality of imprinting is present in normal cells, including circulating blood cells," Mr. Feinberg said. "And when it is abnormal, it is associated with an increased frequency of cancer of the colon, colon benign⁷ tumors and also a positive family history for colon cancer."

Those who had a personal history of colon cancer were nearly 25 percent more likely to have the loss of the imprinting marker in their blood.

Dr. Feinberg says investigators now want to work forward, studying people with no known history of colon cancer, to see if the test accurately⁸ predicts who is likely to develop tumors.

"If that turns out to be the case, which will take several years to find out, then it would be possible to screen people in general with this test, and identify those who are at risk of developing cancer, so that we could either catch it very early, or prevent it altogether," he said.

As is often the case with new procedures, Dr. Feinberg says, the screening test for colon cancer is expensive and difficult to perform. But his team is also looking at ways to simplify it and make it more affordable⁹.

Jessica Berman VOA news, Washington.

1)    detect[di5tekt]vt. 发现,探知，查出，电子检波

2)    abnormality[7AbnC:5mAliti]n. 畸形,异常性

1 mar   

vt.破坏，毁坏，弄糟

参考例句：

• It was not the custom for elderly people to mar the picnics with their presence.大人们照例不参加这样的野餐以免扫兴。
• Such a marriage might mar your career.这样的婚姻说不定会毁了你的一生。

2 colon   

n.冒号，结肠，直肠

参考例句：

• Here,too,the colon must be followed by a dash.这里也是一样，应当在冒号后加破折号。
• The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。

3 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

4 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

5 imprinting   

n.胚教，铭记（动物生命早期即起作用的一种学习机能）；印记

参考例句：

• He gathered her to himself, imprinting kisses upon her lips and cheeks. 他把她抱过来，吻着她的嘴唇和面颊。 来自辞典例句
• It'seems likely that imprinting is an extreme case of conditioning. 看来似乎铭记是适应的一种极端的情况。 来自辞典例句

6 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

7 benign   

adj.善良的，慈祥的；良性的，无危险的

参考例句：

• The benign weather brought North America a bumper crop.温和的气候给北美带来大丰收。
• Martha is a benign old lady.玛莎是个仁慈的老妇人。

8 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。

9 affordable   

adj.支付得起的，不太昂贵的

参考例句：

• The rent for the four-roomed house is affordable.四居室房屋的房租付得起。
• There are few affordable apartments in big cities.在大城市中没有几所公寓是便宜的。