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听力文本
CRISPR Gene Editing Used to Restore Eyesight
Scientists say they have used the gene-editing tool CRISPR to repair a person's eyesight for the first time.
DNA is short for deoxyribonucleic acid. It is the substance that carries genetic information in the cells of living things. The CRISPR tool makes it possible to change DNA to add needed genes or take some away if they lead to problems.
A patient recently had the procedure done for an inherited form of blindness, the companies that make the treatment announced Wednesday. The operation took place at Oregon Health and Science University in Portland. The companies did not release additional details about the patient.
It may take up to a month to see if the procedure worked to repair a patient's vision. If the first few attempts seem safe, doctors plan to test it on 18 children and adults.
"We literally have the potential to take people who are essentially blind and make them see," said Charles Albright. He is chief scientific officer at Editas Medicine in Cambridge, Massachusetts. Editas is one of the companies developing the treatment. The other is Allergan, based in Dublin, Ireland.
Albright added, "We think it could open up a whole new set of medicines to go in and change your DNA."
Dr. Jason Comander is an eye doctor at Massachusetts Eye and Ear in Boston. He said it marks "a new era in medicine" in which technology has made "editing DNA much easier and much more effective."
Doctors first tried in-the-body gene editing in 2017 for a different inherited disease using a tool called zinc fingers. Many scientists believe CRISPR is a much easier tool for finding and cutting DNA at an exact spot.
The people taking part in the study have a genetic condition that keeps the body from making a protein needed to turn light into signals to the brain, which leads to sight. People with the disease are often born with little ability to see. They can lose whatever vision they are born with when they are still very young.
Scientists have found it difficult to treat the condition with usual gene therapy. So, they are aiming to edit or remove the mutation by making two cuts on either side of it. The hope is that the ends of DNA will reconnect and make the gene work as it should.
The procedure is done in an hour-long operation. Through a tube the width of a human hair, doctors put three drops of fluid containing the gene editing machinery just under the retina. That is the lining at the back of the eye that contains the light-sensing cells.
Doctors believe they need to fix one-tenth to one-third of the cells to repair vision. In animal tests, scientists were able to correct half of the cells with the treatment, Albright said.
Some independent experts were hopeful about the new study.
Dr. Kiran Musunuru is a gene-editing expert at the University of Pennsylvania. He said the treatment seems likely to work, based on tests in human tissue, mice and monkeys.
The gene editing tool stays in the eye and does not travel to other parts of the body. So, "if something goes wrong, the chance of harm is very small," Musunuru said. "It makes for a good first step for doing gene editing in the body."
I'm Bryan Lynn.
重点解析
重点讲解：
1. take away 从…中减去；从…中扣除；
I took away the leaves in the gutters.
我清除了檐槽中的树叶。
2. take part in 参加；参与；
You don't need strength to take part in this sport.
参加这项运动不需要太多体力。
3. turn into (使)变成；(使)成为；
The main body of the church had been turned into a massive television studio.
该教堂的主体部分已被改造成了一个大型电视演播室。
4. go wrong (情况)出岔子，出差错；
It all went horribly wrong.
情况完全变得一团糟。
参考译文
CRISPR基因编辑用于恢复视力
科学家表示，他们首次使用基因编辑工具CRISPR来修复人们的视力。
DNA是脱氧核糖核酸的简称。它是生物细胞内携带遗传信息的物质。CRISPR工具使改变DNA成为可能，可以添加所需基因或删除导致问题的基因。
一名患者最近接受了治疗遗传性失明的手术，提供治疗的公司于周三宣布了这一消息。手术在波特兰市的俄勒冈健康与科学大学进行。公司并未公布患者的其他详细信息。
可能需要一个月的时间来观察手术是否能修复患者的视力。如果最初的几次尝试看起来安全，医生计划对18名儿童和成年人进行测试。
查尔斯·奥尔布赖特表示：“我们确实有可能让实际上失明的人重见光明。”他是马萨诸塞州剑桥伊迪达斯医学公司的首席科学官。伊迪达斯公司是其中一家开发这种疗法的公司。另外一家公司是爱尔兰都柏林的艾尔建公司。
奥尔布赖特补充说：“我们认为这可以开发出一整套全新的医学来改变DNA。”
杰森·科曼德博士是位于波士顿的马萨诸塞州眼耳医院的眼科医生。他说，这标志着“医学的新时代”，在这个时代中，技术使“编辑DNA变得更容易也更有效”。
2017年，医生首次尝试用名为锌指的工具进行体内基因编辑，治疗另一种遗传疾病。许多科学家认为，CRISPR是更易于在精确位置寻找和切割DNA的工具。
这项研究的参与者患有遗传病，这种疾病使身体无法制造出将光线转化为传递给大脑的信号继而产生视觉所需的蛋白质。患有这种疾病的人通常天生视力就差。他们可能会在很小的时候就失去所有视力。
科学家发现难以用普通的基因疗法治疗这种疾病。因此，他们的目标是通过在基因两侧进行两次切割来编辑或删除突变基因。他们希望DNA的末端能重新连接，使基因正常工作。
这个步骤是在1小时长的手术中完成的。医生用与人类头发丝一样宽的细管，在视网膜下滴下三滴含有基因编辑装置的液体。视网膜是位于眼睛后部的内膜，含有感光细胞。
医生认为，修复视力需要修复十分之一至三分之一的感光细胞。奥尔布赖特表示，在动物实验中，科学家能用这种疗法修正一半感光细胞。
一些独立专家对这项新研究抱有希望。
基兰·木苏努鲁博士是宾夕法尼亚大学的基因编辑专家。他说，基于对人体组织、小鼠和猴子进行的测试，这项疗法似乎能奏效。
基因编辑工具留在眼睛里，不会移动到身体其他部位。木苏努鲁表示，因此，“如果出现问题，那造成伤害的可能性也非常小。这是在体内进行基因编辑的良好开端”。
布莱恩·林恩报道。
译文为可可英语翻译，未经授权请勿转载！
