题目信息
Symptoms of Parkinson's Disease, such as tremors, are thought to be caused by low dopamine levels in the brain. Current treatments of Parkinson's disease are primarily reactionary, aiming to replenish dopamine levels after dopamine-producing neurons in the brain have died. Without a more detailed understanding of the behavior of dopamine-producing neurons, it has been impossible to develop treatments that would prevent the destruction of these neurons in Parkinson's patients.
Recent research provides insight into the inner workings of dopamine-producing neurons, and may lead to a new drug treatment that would proactively protect the neurons from decay. By examining the alpha-synuclein protein in yeast cells, scientists have determined that toxic levels of the protein have a detrimental effect on protein transfer within the cell. More specifically, high levels of alpha-synuclein disrupt the flow of proteins from the endoplasmic reticulum, the site of protein production in the cell, to the Golgi apparatus, the component of the cell that modifies and sorts the proteins before sending them to their final destinations within the cell. When the smooth transfer of proteins from the endoplasmic reticulum to the Golgi apparatus is interrupted, the cell dies.
With this in mind, researchers conducted a genetic screen in yeast cells in order to identify any gene that works to reverse the toxic levels of alpha-synuclein in the cell. Researchers discovered that such a gene does in fact exist, and have located the genetic counterpart in mammalian nerve cells, or neurons. This discovery has led to new hopes that drug therapy could potentially activate this gene, thereby suppressing the toxicity of alpha-synuclein in dopamine-producing neurons.
While drug therapy to suppress alpha-synuclein has been examined in yeast, fruitflies, roundworms, and cultures of rat neurons, researchers are hesitant to conclude that such therapies will prove successful on human patients. Alpha-synuclein toxicity seems to be one cause for the death of dopamine-producing neurons in Parkinson's patients, but other causes may exist. Most scientists involved with Parkinson's research do agree, however, that such promising early results provide a basis for further testing.
Recent research provides insight into the inner workings of dopamine-producing neurons, and may lead to a new drug treatment that would proactively protect the neurons from decay. By examining the alpha-synuclein protein in yeast cells, scientists have determined that toxic levels of the protein have a detrimental effect on protein transfer within the cell. More specifically, high levels of alpha-synuclein disrupt the flow of proteins from the endoplasmic reticulum, the site of protein production in the cell, to the Golgi apparatus, the component of the cell that modifies and sorts the proteins before sending them to their final destinations within the cell. When the smooth transfer of proteins from the endoplasmic reticulum to the Golgi apparatus is interrupted, the cell dies.
With this in mind, researchers conducted a genetic screen in yeast cells in order to identify any gene that works to reverse the toxic levels of alpha-synuclein in the cell. Researchers discovered that such a gene does in fact exist, and have located the genetic counterpart in mammalian nerve cells, or neurons. This discovery has led to new hopes that drug therapy could potentially activate this gene, thereby suppressing the toxicity of alpha-synuclein in dopamine-producing neurons.
While drug therapy to suppress alpha-synuclein has been examined in yeast, fruitflies, roundworms, and cultures of rat neurons, researchers are hesitant to conclude that such therapies will prove successful on human patients. Alpha-synuclein toxicity seems to be one cause for the death of dopamine-producing neurons in Parkinson's patients, but other causes may exist. Most scientists involved with Parkinson's research do agree, however, that such promising early results provide a basis for further testing.
The primary purpose of the passage is to
A:compare and contrast current treatments for Parkinson`s Disease
B:discuss new scientific findings and the implications of these findings for treating Parkinson`s Disease
C:explain the role of proteins in dopamine-producing neurons
D:introduce new research that supports an already existing treatment method for Parkinson`s Disease
E:question the scientific evidence used to support current treatments for Parkinson`s Disease
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已选答案：
正确答案：
B:discuss new scientific findings and the implications of these findings for treating Parkinson`s Disease
*内容概述：
文章开头说女性的草根运动时期和他们对新文明意识的看法的核心来自于美国在大推进时期的社会改革。接着进一步解释在这一时期中产白人女性改革者取得的成就。接下来笔锋一转，在童工问 题上不同阶级女性看法不同。改革者认为必须剔除，但工人阶级则认为童工法会让家庭里干活的人变少，生活难以为继。最后是作者的评价，承认改革者要求不适用童工是正确的，但他们没有考 虑到工人阶级的家庭经济状况
*文章类型：人文历史
*文章套路：对比解释说明
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*题目类型：主旨题
*选项分析：主旨题去看全文内容概述。本文的目的就是文章的结尾处说的中产阶级改革者没能够理解公认阶级的经济状况。因此正确答案是D
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