Japanese doctors have used thin sheets of tissue from people’s cheeks to repair damaged corneas(角膜). A team from Osaka University transplanted thin layers of cheek cells onto the eyes of four patients with a rare and painful eye condition, reports BBC online. Patients whose vision had been cloudy could see well afterwards, and the “new corneas” remained clear more than a year after the operation.
Doctors can also take cells from a healthy eye and grow them in a dish to produce a new cornea, or they can transplant corneas from donors. But these techniques may not work when both eyes are too badly damaged by accident or disease.
The team hope their work may help solve the problem and lead to other types of grow-your-own tissue transplants. The cornea is the clear layer of cells on the surface of the eye. It can be damaged by trauma(外伤) or by a range of diseases.
The team worked with four patients who had a painful condition that caused cloudy corneas and dry eyes. Often the eye can regenerate cornea cells but none of the four patients had this ability. The researchers took a 3 mm-wide square of tissue from inside the mouth(cheeks) and grew it into q thin layer in the lab. They used a special low-temperature technique to separate a very think sheet off each batch(组). They then laid that onto the patient’s eye. The cell layers stuck onto the eye and developed into tissue that looked and acted like a healthy cornea.
However, long-term follow-up and experience with a large series of patients are needed to assess the benefits and risks of this method. “Yet, it does offer the potential of treating severe eye diseases that are resistant to standard approaches,” said the head of the research, Kohji Nishida.
1. Now doctors can repair the damaged corneas with the following methods EXCEPT ______.
A. using mouth tissue
B. taking cells from a healthy eye and growing them in a dish
C. transplanting corneas from another person
D. using finger tissue
2. If both eyes are too badly damaged, we can treat them ______.
A. only by using mouth tissue
B. by taking cells from a healthy eye and growing them in a dish
C. by transplanting healthy corneas from donors
D. by none of the mentioned methods.
3. We can infer from the passage that ______.
A. the new technique can be widely used in the operations
B. the new technique needs to be further tested
C. the new technique has more benefits than risks
D. any new technique has risks
4. Which of the following is the best title?
A. A New Invention
B. A New Technique
C. Mouth Tissue Can Restore Your Vision
D. Transplanting Can Restore Your Vision
答案解析
1. D 前三项的方法都在文中有所提及，但D项没有。
2. D 根据第一段和第二段提到的技术及第二段“But these techniques may not work when both eyes are too badly damaged by accident or disease”可知，these techniques即是指本题中前三项的内容。
3. B 由最后一段第一句可知。
4. C 本文主要讲述的是利用嘴部组织来修复受损的眼角膜技术。
157_1501141445093nn1ibuG0tYRn5br.gif
group.png
157_150114145108aIRz3bYo5LSySjIH.jpg
157_150114144608mCYYOuujzYzJOq1K.jpg
| 
发表于 2016-7-24 09:45:41