VOA常速英语2014--猪膀胱助病人的干细胞生长出新肌肉（在线收听）

Pigs’ Bladder Helps Patients' Stem Cells Grow Missing Muscles 猪膀胱助病人的干细胞生长出新肌肉

The promise that stem cells may someday help regenerate damaged tissue seems to be close to fulfillment. Scientists at the University of Pittsburgh School of Medicine report that some of their severely injured patients grew new muscle tissue with the help of pigs’ bladders.

After a skiing accident in which he lost much of the muscle in his left calf, Nicholas Clark could no longer do many of his regular activities.

在一次滑雪事故中左小腿失去了很多肌肉后,尼古拉斯·克拉克再也不能像往常那样投身于许多活动之中了。

“In addition to the muscle loss, I had a lot of nerve loss and blood vessel loss and other tissue loss in that leg.So, it really limited any activity."

“除了肌肉损失, 腿部还有很多神经，血管及其他组织受损。所以,这真的限制我的一切活动。”

Skeletal muscles can regenerate after minor injuries with help from physical therapy, but if the loss is greater than 20 percent, the damage becomes permanent, says Doctor Stephen Badylak of the University of Pittsburgh School of Medicine.

匹兹堡大学医学院医生斯蒂芬·贝狄拉克表示轻伤在物理治疗的帮助下骨骼肌可以再生,但如果损伤超过20%,就会成为永久性损害。

“You're left with this huge gap that just fills in with scar tissue."

“你留下这个巨大的缺口,只能是用疤痕组织填补。”

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Scientists have long known that stem cells, applied at the point of injury, can actually turn into new muscle cells. But they need some sort of structure-a matrix-to grow on.

科学家早就知道干细胞作用于伤患处可以变成新的肌肉细胞。但是它们需要某种结构—一种基质才能生长。

Badylak's team created an “extracellular matrix” from a pig's bladder. They removed all traces of cells from the tissue, so that the recipient's immune system would not reject it.

贝狄拉克的团队从猪的膀胱中创造了一种“细胞外基质”。他们从组织中移除所有细胞的相关痕迹,这样接受者的免疫系统就不会拒绝。

“The extracellular matrix is the glue, if you will, that holds all of the cells in our body together."

细胞外基质是一种胶状物质,如果你愿意,会将我们身体的所有细胞聚合在一起。”

The matrix is implanted at the injury site, and as it slowly degrades in recipient's body it releases chemicals that attract stem cells. Physical therapy helps the stem cells understand that they need to form muscle tissue.

这种基质是在受伤部位植入,随着它缓慢在接受者的体内降解，会释放吸引干细胞的化学物质。就是这样的物理疗法帮助干细胞理解它们需要形成肌肉组织。

All five patients in Badylak's study had lost 60 to 90 percent of the affected muscle. Six months after the start of therapy, all have grown some new muscle, and three patients had dramatic improvement. Clark says he can ride his bike again and even jump rope.

贝狄拉克研究的所有5位病人失去了60-90%的肌肉。而6个月的治疗结束后,所有人都长出了新肌肉,而且3位病人得到戏剧性的改善。克拉克表示他又能骑自行车甚至跳绳。

“There are other things, just day to day things, that really make a huge difference."

“还有其他事情,每一天都在发生改变,真正产生巨大变化。”

Scientists say they experimented mostly with old injuries, but that the new method probably works better for patients with more recent injuries.

科学家表示他们大多是用旧患进行尝试,但是这种新方法可能对于最近的伤病患者效果更为突出。