Question

    Drug companies have spent billions of dollars searching for therapies to reverse or significantly slow Alzheimer’s disease, but in vain. Some researchers argue that the best way to make progress is to create better animal models for research, and several teams are now developing mice that more closely imitate how the disease destroys people’s brains.

The US National Institutes of Health (NIH), the UK Dementia Research Institute and Jackson Laboratory (JAX) - one of the world’s biggest suppliers of lab mice - are among the groups trying to genetically design more suitable mice. Scientists are also exploring the complex web of mutations(突变) that influences neurological(神经学的) decline in mice and people.

“We appreciate that the models we had were insufficient. I think it’s sort of at a critical moment right now.” says Bruce Lamb, a neuro-scientist at Indiana University who directs the NIH-funded programme.

Alzheimer’s is marked by cognitive impairment(认知损伤) and the build-up of amyloid-protein plaques(淀粉样蛋白块) in the brains of people, but the disease does not occur naturally in mice. Scientists get around this by studying mice that have been genetically modified to produce high levels of human amyloid protein. These mice develop plaques in their brains, but they still do not display the memory problems seen in people.

Many experimental drugs that have successfully removed plaques from mouse brains have not lessened the symptoms of Alzheimer’s disease in people. One focused stumble came last month, when three companies reported that their Alzheimer’s drugs had failed in large, late-stage clinical trials. Although the drugs successfully blocked the accumulation of amyloid protein in mice, they seemed to worsen cognitive decline and brain shrinkage in people.

The drive for better mouse models comes as genomics studies are linking the most common form of Alzheimer’s to dozens of different genes. This diversity suggests that each case of the disease is caused by a different combination of genetic and environmental factors. “There is no single Alzheimer’s disease,” says Gareth Howell, a neuro-scientist at Jackson Laboratory (JAX) in Bar Harbor, Maine.

Howell argues that scientists’ reliance on lab mice with only a few genetically engineered mutations might have limited research. His own work suggests that in mice, just as in people, genetic diversity plays a part in determining how Alzheimer’s develops.

1.What do you know about the lab mice used for the Alzheimer’s research from the text?

A.The lab mice also display the memory problems.

B.Suitable lab mice are fundamental to the research.

C.Mice with Alzheimer’s disease suffer from mutations.

D.Drugs have been invented to slow Alzheimer’s disease.

2.From paragraph 5, we can know that the experimental drugs “__________”.

A.functioned well in large, early-stage clinical trials

B.fail to make people get rid of the relevant symptoms

C.successfully prevent people forming amyloid protein

D.worsen cognitive decline and brain shrinkage in mice

3.What does Gareth Howell think of Alzheimer’s?

A.It is various genes that count in the development of Alzheimer’s.

B.The increasingly polluted environment contributes to Alzheimer’s.

C.The most common form of Alzheimer’s is the drive for better mice.

D.It is caused by the accumulation of amyloid-protein plaques in people.

4.Which of the following could be the best title for the passage?

A.Experimental drugs successfully reverse Alzheimer’s

B.The real causes of Alzheimer’s have been confirmed

C.Alzheimer’s is the biggest memory killer in the aged

D.Frustrated Alzheimer’s researchers seek better lab mice

Answer

1.B

2.B

3.A

4.D

【解析】

本文是一篇说明文。文章讲述的是为了更好的研究阿尔茨海默氏症，Alzheimer研究人员在寻找更好的实验小鼠。

1.推理判断题。根据第二段中one of the world's biggest suppliers of lab mice - are among the groups trying to genetically design more suitable mice.(世界上最大的实验室小鼠供应商之一——都在试图通过基因设计出更合适的小鼠的团队之中。)可推断，合适的实验小鼠是这项研究的基础。故选B。

2.推理判断题。根据第五段中Although the drugs successfully blocked the accumulation of amyloid protein in mice, they seemed to worsen cognitive decline and brain shrinkage in people.“尽管这些药物成功地阻止了小鼠淀粉样蛋白的积累，但它们似乎加剧了人类的认知衰退和脑萎缩。”可知，从第5段可以看出，实验药物“并不能使人摆脱相关症状”。故选B。

3.推理判断题。根据最后一段中His own work suggests that in mice, just as in people, genetic diversity plays a part in determining how Alzheimer's develops.(他自己的研究表明，在老鼠身上，正如在人类身上一样，基因多样性在决定阿尔茨海默氏症的发展过程中起着重要作用。)可推断，Gareth Howell认为在Alzheimer的发展过程中起作用的是各种基因。故选A。

4.主旨大意题。根据第一段中Some researchers argue that the best way to make progress is to create better animal models for research, and several teams are now developing mice that more closely imitate how the disease destroys people's brains.“一些研究人员认为，取得进展的最佳方式是为研究创造更好的动物模型，目前有几个研究小组正在开发更接近于模仿这种疾病如何破坏人类大脑的小鼠。”和最后一段中His own work suggests that in mice, just as in people, genetic diversity plays a part in determining how Alzheimer's develops.“他自己的研究表明，在老鼠身上，就像在人身上一样，基因多样性在决定Alzheimer的发展过程中发挥着作用。”可知，本文讲述的是感到沮丧的Alzheimer研究人员在寻找更好的实验小鼠。故选D。