VOA标准英语2010年-Regrowing Worn Joints Using Patient St

Various stages of cartilage growth on scaffold. The final image on the right shows naturally forming cartilage for comparison.

These replacement¹ joints³ can be made of combinations of metal alloys⁴, plastic and ceramic⁵, but new research shows that it might be possible to regenerate⁶ damaged joints using a patient's own stem cells.

Chronic⁷ disability

Osteoarthritis is the result of infection, trauma⁹ or simply age, and is the leading cause of chronic disability worldwide.

The disease causes cartilage-protecting joint² surfaces to degrade, allowing painful bone-to-bone contact. Osteoarthritis is usually treated with pain relievers and anti-inflammatory drugs, but in severe cases, the damaged joint can be replaced with an artificial one. However, this option may not work well for the growing population of younger arthritic¹⁰ patients.

"The average lifespan of the metal joints is about 10 to 15 years," says Jeremy Mao at the Columbia University Medical Center. "So as you can imagine, if you are say 50, 55 or younger, the surgeons will be very hesitant to place these metal joints in your body because knowing that in 10 to 15 years, there's a chance these would fail."

In order to address this concern, Mao is exploring new ways to regenerate joints.

fpjacquot/Wikimedia Commons
This x-ray shows shows an artificial knee joint, but now scientists are exploring regenerating¹¹ damaged joints using a patient's own stem cells.

Growing new joint cells

Mao replaced a portion of a rabbit's upper arm joint with a biomaterial scaffold, providing a place for cells to grow. In order to attract the rabbit's own stem cells to re-grow the cartilage, channels in the scaffold were filled with a growth factor protein.

"What we found was with one protein that we delivered in the micro-channels in the scaffolds, that was sufficient to regenerate the entire joint surface with cartilage and with bone and with blood vessels," says Mao. "So when we observe these animals with the replacement joints, what we found was there was regeneration of the entire joint that allowed the animals to resume weight-bearing and locomotion¹²."

This return to normalcy occurred just four months after the surgical¹³ procedure, with newly grown cartilage fully¹⁴ covering the joint surface. When the mechanical properties of this new cartilage were tested, they showed that the regenerated¹⁵ cells were just as effective as the rabbit's naturally formed cartilage.

Added benefits

While human trials are still a long way off, scientists in the field are excited and encouraged by the research.

"It's absolutely necessary that we continue to push the envelope in terms of try to develop new innovative¹⁶ and more natural ways of effectively treating arthritis⁸," says Dr. Mary O'Connor, chairperson of Orthopedic Surgery at the Mayo Clinic in Florida.

O'Connor says there is significant benefit to using this type of treatment for arthritis in the knee.

"When we do a knee replacement, we remove one or sometimes both of the cruciate ligaments - which are the ligaments in the center of the knee. So one of the potential advantages of this growing joint technique is perhaps the ability to preserve more of those tissues inside the knee, which would hopefully translate into more natural mechanics of the knee."

O'Connor says cost could be a factor in deciding to use this treatment. While it may not be worthwhile for older patients, younger patients are more likely to regard anything that gives them a lifelong working knee joint as well worth the cost.

 

1 replacement   

n.取代，替换，交换；替代品，代用品

参考例句：

• We are hard put to find a replacement for our assistant.我们很难找到一个人来代替我们的助手。
• They put all the students through the replacement examination.他们让所有的学生参加分班考试。

2 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

3 joints   

接头( joint的名词复数 )； 关节； 公共场所（尤指价格低廉的饮食和娱乐场所） （非正式）； 一块烤肉 （英式英语）

参考例句：

• Expansion joints of various kinds are fitted on gas mains. 各种各样的伸缩接头被安装在煤气的总管道上了。
• Expansion joints of various kinds are fitted on steam pipes. 各种各样的伸缩接头被安装在蒸气管道上了。

4 alloys   

n.合金( alloy的名词复数 )

参考例句：

• This is essentially a development of thoria dispersion strengthened nickel alloys. 这基本上是用二氧化钍弥散强度化的镍基合金。 来自辞典例句
• The lack of deep hardening in these alloys negates their use. 这些合金缺乏深层硬化能力使它们无法利用。 来自辞典例句

5 ceramic   

n.制陶业，陶器，陶瓷工艺

参考例句：

• The order for ceramic tiles has been booked in.瓷砖的订单已登记下来了。
• Some ceramic works of art are shown in this exhibition.这次展览会上展出了一些陶瓷艺术品。

6 regenerate   

vt.使恢复，使新生；vi.恢复，再生；adj.恢复的

参考例句：

• Their aim is to regenerate British industry.他们的目的是复兴英国的工业。
• Although it is not easy,you have the power to regenerate your life.尽管这不容易，但你有使生活重获新生的能力。

7 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

8 arthritis   

n.关节炎

参考例句：

• Rheumatoid arthritis has also been linked with the virus.风湿性关节炎也与这种病毒有关。
• He spent three months in the hospital with acute rheumatic arthritis.他患急性风湿性关节炎，在医院住了三个月。

9 trauma   

n.外伤，精神创伤

参考例句：

• Counselling is helping him work through this trauma.心理辅导正帮助他面对痛苦。
• The phobia may have its root in a childhood trauma.恐惧症可能源于童年时期的创伤。

10 arthritic   

adj.关节炎的

参考例句：

• Somehow the geriatric Voyager 2, arthritic and partially deaf, managed to reach Neptune. 得了关节炎而且局部变聋、衰老的“旅行者2号”最后总算抵达海王星。 来自百科语句
• Femoral head ostectomy is a surgery performed on severely arthritic dogs. 股骨断截骨术’都是针对关节炎严重的狗狗的手术。 来自互联网

11 regenerating   

v.新生，再生( regenerate的现在分词 )；正反馈

参考例句：

• It is not proposed to deal with the detailed histology of regenerating tissues here. 这里未提出详细的再生组织的组织学。 来自辞典例句
• This is accomplished by using a thermocompressor to recycle regenerating steam through the absorber. 它用热压机使再生蒸汽经吸附器循环完成解吸过程。 来自辞典例句

12 locomotion   

n.运动，移动

参考例句：

• By land,air or sea,birds are masters of locomotion.无论是通过陆地，飞越空中还是穿过海洋，鸟应算是运动能手了。
• Food sources also elicit oriented locomotion and recognition behavior patterns in most insects.食物源也引诱大多数昆虫定向迁移和识别行为。

13 surgical   

adj.外科的，外科医生的，手术上的

参考例句：

• He performs the surgical operations at the Red Cross Hospital.他在红十字会医院做外科手术。
• All surgical instruments must be sterilised before use.所有的外科手术器械在使用之前，必须消毒。

14 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

15 regenerated   

v.新生，再生( regenerate的过去式和过去分词 )

参考例句：

• They are regarded as being enveloped in regenerated gneisses. 它们被认为包围在再生的片麻岩之中。 来自辞典例句
• The party soon regenerated under her leadership. 该党在她的领导下很快焕然一新。 来自辞典例句

16 innovative   

adj.革新的，新颖的，富有革新精神的

参考例句：

• Discover an innovative way of marketing.发现一个创新的营销方式。
• He was one of the most creative and innovative engineers of his generation.他是他那代人当中最富创造性与革新精神的工程师之一。