Unit 92
A widely heralded but still experimental cancer-fighting compound may be used someday to prevent two other major killers of Americans: heart disease and stroke. That was the implication of a remarkable report published last week in the journal Circulation by a team of researchers from Dr. Judah Folkman's laboratory at the Children's Hospital in Boston.
The versatile compound is endostatin, a human protein that inhibits angiogenesis, the growth of new blood vessels in the body. In tests reported in 1997 by Folkman, a prominent cancer researcher who pioneered the study of angiogenesis, the drug had reduced and even eradicated tumors in laboratory mice. How? By stunting the growth of capillaries necessary for nourishing the burgeoning mouse tumors.
When news of Folkman's achievement became widely known last year, it led to wildly exaggerated predictions of imminent cancer cures. When other scientists were initially unable to duplicate those results, questions arose about the validity of Folkman's research. Then in February scientists at the National Cancer Institute, with guidance from Folkman, finally matched his results. Reassured, the N.C.I. gave the go-ahead for clinical trials of endostatin later this year on patients with advanced tumors.
How can a drug that is apparently effective against tumors also reduce the risk of heart attack and stroke? The answer lies in the composition of plaque, the fatty deposit that builds up in arteries and can eventually clog them. Plaque consists of a mix of cholesterol, white blood cells and smooth muscle cells, and as it accumulates, a network of capillaries sprouts from the artery walls to nourish the cells. Could endostatin halt the growth of capillaries and starve the plaque?
A Folkman lab team led by Dr. Karen Moulton decided to find out. The scientists put baby lab mice on a 16-week "Western diet" that was high in fat and cholesterol, then measured the plaque buildup on the walls of each aorta, the large artery that carries blood from the heart to the rest of the body. Meanwhile, they injected one group of mice with endostatin, another with a different blood-vessel inhibitor called TNP-470 and a control group with an inert saline solution. Twenty weeks later the researchers again measured plaque in the mouse aortas. The results were startling: the endostatin group averaged 85% less plaque buildup and the TNP-470 group 70% less than those in the control group.
All too aware of the premature hopes raised last year after Folkman's tumor report, the researchers have been careful not to oversell the new results. "If this finding is supported in future studies," says Moulton, "[it could open the way for] treatments that could delay the progression of heart disease and possibly reduce the incidence of heart attacks and strokes." But any such treatments, she stresses, are probably five to 10 years away.
注(1):本文选自Time; 04/19/99, p48;
注(2):本文习题命题模仿对象2004年真题Text 1;
1. What did the report indicate?
[A]A very important drug is now at experimental stage.
[B]Heart disease and stroke are the most serious threats to Americans.
[C]The tumor drug can be used for the heart disease in the future.
[D]Many Americans suffer from heart disease and stroke.
2. Why did the N.C.I. agree to have clinical trials of endostatin on the patients?
[A]They were convinced of the Folkman's research.
[B]They can do such a research as well as Folkman.
[C]The patients with advanced tumors need the drug.
[D]The drug should be proved effective on humans.
3. The expression “stunting the growth of capillaries”(Line 8, Paragraph 2) most probably means _______.
[A]help the growth of capillaries
[B]limit the growth of capillaries
[C]improve the growth of capillaries
[D]prevent the growth of capillaries
4. Why can the tumor drug be used for the heart?
[A]It can accumulate a network of capillaries and nourish the cells.
[B]It can stop the growth of capillaries and provide no nourishment for plaque.
[C]The curing method of tumor and heart disease is the same.
[D]The tumor and heart disease are made up of the same substance.
5. Which of the following is true according to the text?
[A]Folkman's tumor report had been exaggerated.
[B]The tumor drug is not as effective as what has been expected.
[C]The new results of the research are far more encouraging.
[D]Researchers still have a long way to go to make another successful experiment.
答案:CADBC
篇章剖析
本文采用的是提出问题——解析问题的模式,指出一种抗癌制剂也可以用于治疗动脉硬化症的作用机理及其意义。在第一段指出《循环》杂志报道了一种抗癌制剂也可以用于治疗动脉硬化症;第二段和第三段指出这一药物对于癌症患者的作用和意义;第四段和第五段指出实验证明这种药物同样对心脏疾病患者起作用,并分析其原因;第六段指出这一发现的意义。
词汇注释
atherosclerosis[AWErEJsklIE5rEJsIs]n.[医]动脉硬化症
herald[5herEld]vt.预报, 宣布, 传达, 欢呼
endostatin血管内皮抑制素
angiogenesis 血管新生
stunt[stQnt]v.阻碍……发育, 妨碍……生长, 作惊人表演, 使绝招
capillary[kE5pIlErI]n.毛细管
burgeon[5b\:dV(E)n]v.萌芽
imminent[5ImInEnt]adj.即将来临的, 逼近的
validity[vE5lIdItI]n.有效性, 合法性, 正确性
go-ahead adj.前进着的n.<俗>前进, 进步, 放行信号
plaque[plB:k; (?@) 5plAk]n斑动脉血管壁内脂肪物质的沉积,以动脉粥样硬化为特征;肿瘤
build up v.树立, 增进, 增大, 堵塞
cholesterol[kE5lestErRl]n.胆固醇
sprout[spraJt]v.萌芽
aorta[eI5C:tE]n.大动脉
control group n.对照组
inert[I5n\:t]adj.无活动的, 惰性的, 迟钝的
saline[5seIlaIn; (?@) 5seIli:n]adj.盐的, 苦涩的, 由碱金属(或含镁之盐类)组成的
难句突破
The scientists put baby lab mice on a 16-week "Western diet" that was high in fat and cholesterol, then measured the plaque buildup on the walls of each aorta, the large artery that carries blood from the heart to the rest of the body.
主体句式:the scientists put baby lab mice on…, then …
结构分析:“then”起到衔接的作用,把两个完整的句子连接起来。在第一个句子中,“that”引导定语从句修饰“western diet”;在第二个句子中,“buildup”是名词,“the large artery”是“aorta”的同位语,“that”引导定语从句来修饰“the large artery”。
句子译文:科学家们把实验室的幼鼠喂养了十六周的高脂肪、高胆固醇的“西式食物”之后,然后测量每个大动脉壁上的栓塞增长情况。大动脉的功能是把血液从心脏输往身体其它部位。
题目分析
1.答案为C,属推理判断题。原文对应信息是“A widely heralded but still experimental cancer-fighting compound may be used someday to prevent two other major killers of Americans: heart disease and stroke.”选项A、B、D都是片段信息,不完整。
2.答案为A,属推理判断题。原文对应信息“Reassured, the N.C.I. gave the go-ahead for clinical trials of endostatin later this year on patients with advanced tumors.”从本段我们得知,刚开始的时候,当其他科学家无法重复那些试验结果时,他们对福克曼这项研究的正确性也就产生了疑问。后来,美国国家癌症研究所的科学家在福克曼的指导下,最终验证了他的结果。实验结果使他们信服,他们才同意把它用于临床实验。
3.答案为D,属猜词题。文中提到治疗癌症的药物也能治疗心脏疾病,是因为其中的一些作用机理是一样的。如果不明白“stunting the growth of capillaries”是什么意思的话,在文中第四段又提到了类似的一句话“Could endostatin halt the growth of capillaries and starve the plaque?”这两句话的意思是非常近似的。从这句话所在的上下文语境我们可以得出“halt”的意思,由此可推出“stun”的含义。
4.答案为B,属推理判断题。文中提到治疗癌症的药物也能治疗心脏疾病,是因为其中的一些作用机理是一样的。治疗癌症药物之所以起作用是通过“By stunting the growth of capillaries necessary for nourishing the burgeoning mouse tumors. ”这种药物能否治疗心脏疾病,关键也在于此“Could endostatin halt the growth of capillaries and starve the plaque?”通过实验证明,答案是肯定的。因此不难作出判断。
5.答案为C,属推理判断题。从文中最后一段我们可看出这一发现意义重大。
参考译文
一种广为宣传但仍处于实验阶段的抗癌化合物有朝一日可能会用来抑制危害美国人生命的两大元凶:心脏病和中风。这是上周发表在《循环》杂志上的一篇文章所暗含的意思。这篇不同凡响的报道是由波士顿儿童医院尤达·福克曼博士实验室的研究人员撰写的。
这种多用途化合物叫做血管内皮抑制素。这是一种抑制血管新生,也就是抑制人体内新的血管生长的人体蛋白质。这种药品在福克曼1997年记载的试验中可以减少、甚至根除实验鼠体内的肿瘤。福克曼是一位著名的癌症研究者,他开辟了对血管新生的研究。那么这是怎么起作用的呢?通过阻碍老鼠体内迅速增长的肿瘤获取营养所必须的毛细血管的生长。
去年,当福克曼取得的成果公之于众的时候,人们对这种即将到来的癌症治疗方法做出了最
为大胆的预测。最初,当其他科学家无法重复那些试验结果时,他们对福克曼这项研究的正确性也就产生了疑问。二月份,美国国家癌症研究所的科学家在福克曼的指导下,最终验证
了他的结果。打消了疑虑,国家癌症研究所今年下半年准许在癌症晚期的病人身上进行血管内皮抑制素临床实验。
一种对于治疗肿瘤明显有效的药物怎么还能减少心脏病和中风发作的危险呢?答案在于栓塞的成分——这种脂肪沉积在动脉上逐渐增加,并最终阻塞动脉。栓塞是由胆固醇、白血细胞和平滑的肌肉细胞组成的混合体构成。随着沉积物质的积聚,就会从动脉壁上产生毛细血管网,为细胞提供养分。血管内皮抑制素能中断毛细血管的生长,从而饿死栓塞吗?
由卡伦·莫尔顿博士领导的福克曼实验室小组成员决定找出答案。科学家们把实验室的幼鼠喂养了十六周的高脂肪、高胆固醇的“西式食物”之后,然后测量每个大动脉壁上的栓塞增长情况。大动脉的功能是把血液从心脏输往身体其它部位。同时,他们给一组实验鼠注射血管内皮抑制素,另一组注射一种叫做TNP-470的血管抑制剂,对照组注射一种惰性盐溶液。二十周之后,研究人员重新测量老鼠动脉上的栓塞。实验结果令人吃惊:使用血管内皮抑制素的小组,老鼠体内的肿瘤增长平均降低85%,使用TNP-470的小组与对照组相比降低了70%.
研究人员深刻认识到,去年公布了福克曼有关肿瘤的报道之后,过早地给人以希望。他们这次就比较谨慎,不过分宣扬他们的新成果。“如果以后的研究能够证实这一发现的话,”莫尔顿说,“(这将为今后的治疗开辟道路。)这些治疗能够延迟心脏病病情的发展,甚至可能会减少心脏病和中风的发病率。”但是她强调说,任何这样的治疗,可能都要再等五到十年。
联系客服