2006年VOA标准英语-Australian Stem Cell Discovery Could Help

By Claudia Blume
Hong Kong
05 January 2006

Scientists in Australia have discovered a stem cell that is expected to provide clues about how breast cancer develops, and how cancer cells evade¹ current therapies. The discovery could be a breakthrough in the treatment of breast cancer.

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Standard mammogram  
  

Researchers at the Victorian Breast Cancer Consortium in the Australian city of Melbourne say they have discovered the stem cell that controls the formation of breast tissue.

Stem cells are the basic building blocks of all body parts, from muscles to blood vessels² to nerves.

The Australians isolated³ these newly identified stem cells from the breasts of female mice.

Under normal circumstances, this type of stem cell produces healthy breast tissue. But a genetic⁴ predisposition to cancer, or exposure to carcinogens (cancer-causing agents), can cause a particular cell to grow into a cancerous tumor⁵.

The existence of these "rogue⁶" stem cells could explain why some women begin developing breast tumors again following chemotherapy - a development that has puzzled scientists and doctors for many years.

Chemotherapy is most effective at destroying cancer cells that divide rapidly. But the newly found stem cell divides slowly: it can survive for months or even years after chemotherapy, and then break out into a new cancer.

The leader of the Australian research team, Jane Visvader, says the main goal of her team is to understand how these stem cells work, and then find a drug that will stop them from becoming malignant⁷.

"The main goal is to understand the nature of both the normal stem cells and the stem cells that become aberrant⁸ and accumulate errors and therefore, use this information to try and design drugs to target these cells," she said.

Ms. Visvader says it could take 10 to 20 years to develop such a drug. In the next step of the research, tumor samples from human breast cancer patients will be analyzed⁹ to confirm the findings of the mouse model.

Ms. Visvader says the research team was also able to grow fully¹⁰ functional¹¹ breasts in mice from the stem cells. But she says that growing new breasts in human patients to replace breasts removed because of cancer is only a remote possibility.

"And that is because mice and [human] breast tissue differ quite significantly in their make-up," she explained. "The hormones¹² and growth factors that are likely to be involved in regenerating¹³ the breast will also be involved in the tumor-genic process that is leading cells to become cancerous."

In other words, the same factors that might cause a new breast to grow might also cause a new cancer.

The findings of the Australian researchers, published in the scientific journal Nature this week, have been corroborated¹⁴ by a Canadian research team.

1 evade   

vt.逃避，回避；避开，躲避

参考例句：

• He tried to evade the embarrassing question.他企图回避这令人难堪的问题。
• You are in charge of the job.How could you evade the issue?你是负责人，你怎么能对这个问题不置可否？

2 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》

3 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

4 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。

5 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。

6 rogue   

n.流氓；v.游手好闲

参考例句：

• The little rogue had his grandpa's glasses on.这淘气鬼带上了他祖父的眼镜。
• They defined him as a rogue.他们确定他为骗子。

7 malignant   

adj.恶性的，致命的；恶意的，恶毒的

参考例句：

• Alexander got a malignant slander.亚历山大受到恶意的诽谤。
• He started to his feet with a malignant glance at Winston.他爬了起来，不高兴地看了温斯顿一眼。

8 aberrant   

adj.畸变的，异常的，脱离常轨的

参考例句：

• His aberrant behavior at the party shocked everyone.他在晚会上的异常举止令所有人感到震惊！
• I saw that the insects and spiders were displaying the same kind of aberrant behavior.我看到昆虫和蜘蛛正在表现出相同反常的行为。

9 analyzed   

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》

10 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

11 functional   

adj.为实用而设计的，具备功能的，起作用的

参考例句：

• The telephone was out of order,but is functional now.电话刚才坏了，但现在可以用了。
• The furniture is not fancy,just functional.这些家具不是摆着好看的，只是为了实用。

12 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

13 regenerating   

v.新生，再生( regenerate的现在分词 )；正反馈

参考例句：

• It is not proposed to deal with the detailed histology of regenerating tissues here. 这里未提出详细的再生组织的组织学。 来自辞典例句
• This is accomplished by using a thermocompressor to recycle regenerating steam through the absorber. 它用热压机使再生蒸汽经吸附器循环完成解吸过程。 来自辞典例句

14 corroborated   

v.证实，支持（某种说法、信仰、理论等）( corroborate的过去式 )

参考例句：

• The evidence was corroborated by two independent witnesses. 此证据由两名独立证人提供。
• Experiments have corroborated her predictions. 实验证实了她的预言。 来自《简明英汉词典》