'Miracle' stem cells help burns victims to see clearly again

Dozens of people whose eyes were severely damaged in chemical accidents have had their sight restored with transplants of their own stem cells.

數十位眼睛在化學事故中嚴重損傷的患者通過自體幹細胞移植而成功恢複了視力 。

Researchers say the technique returned normal vision to nearly 100 people. They said one of the patients could see clearly for the first time in more than 60 years.

研究者稱該技術讓大約一百位患者恢複了正常的視力 。他們說其中一名患者在眼瞎60年之後首次重新看見了一個明亮的世界 。

'They were incredibly happy. Some said it was a miracle,' study leader Graziella Pellegrini of the University of Modena's Center for Regenerative Medicine said. 'It was not a miracle. It was simply a technique.'

“他們樂瘋了 。有人說這是一個奇跡 。” 研究小組組長 、摩德納大學再生醫學中心的Graziella Pellegrini說 ，“我說呢 ，這並非奇跡 ，技術而已 。”


Stem cell transplants offer hope to the thousands of people worldwide every year who suffer chemical burns on their corneas from heavy-duty cleansers or other substances at work or at home.

幹細胞移植給了全世界每年因為化學燒傷角膜的數千患者治愈的希望 ，這些患者通常是在工作場所或家中因接觸強腐蝕力的清潔劑而不慎灼傷 。

In the study researchers took a small number of stem cells from a patient's healthy eye, multiplied them in the lab and placed them into the burned eye, where they were able to grow new corneal tissue to replace what had been damaged.

在本研究中 ，研究者從患者的健康眼取下少量幹細胞 ，然後在實驗室中培養繁殖 ，最後移植到燒傷的患眼 。移植後的幹細胞會生長為新的角膜從而替代原來受損的角膜組織 。

Since the stem cells are from their own bodies, the patients do not need to take anti-rejection drugs.

因為幹細胞來自患者自已的身體 ，所以移植手術後患者無須攝服抗免疫排斥藥物 。

Currently, people with eye burns can get an artificial cornea, a procedure that carries such complications as infection and glaucoma, or they can receive a transplant using stem cells from a cadaver, but that requires taking drugs to prevent rejection.

眼睛燒傷後 ，目前所能得到的治療是人工角膜移植或屍體角膜移植 ，但前者導致的諸如感染與青光眼等並發症嚴重 ，後者必須服藥以預防免疫排斥反應 。

The Italian study involved 106 patients treated between 1998 and 2007. Most had extensive damage in one eye, and some had such limited vision that they could only sense light, count fingers or perceive hand motions. Many had been blind for years and had had unsuccessful operations to restore their vision.

這項在意大利完成的研究涉及了106名患者 ，他們在1998年和2007年接受了幹細胞移植 。其中大多數患者的一隻眼睛有廣泛性損傷 ，其中一些人視力非常有限 ，隻有光感 、隻能能數手指頭或感知手的運動 。許多患者多年眼盲 、接受過不成功的視力恢複手術 。

The cells were taken from the limbus, the rim around the cornea, the clear window that covers the colored part of the eye. In a normal eye, stem cells in the limbus are like factories, churning out new cells to replace dead corneal cells. When an injury kills off the stem cells, scar tissue forms over the cornea, clouding vision and causing blindness.

研究中的幹細胞取自異色邊緣即角膜緣（角膜是覆蓋眼睛有色部分的透明窗口） 。正常眼睛中的異色邊緣中的幹細胞就象工廠 ，能夠生產出新的細胞來替代死亡的角膜細胞 。當損傷殺滅了幹細胞 ，瘢痕組織就替代了角膜 ，遮擋了視線而引起失明 。

In the study, published by the New England Journal of Medicine, the doctors removed scar tissue over the cornea and glued the laboratory-grown stem cells over the injured eye.

本研究發表於《新英格蘭醫學雜誌》（NEJM） ，研究中醫生移除了角膜上的瘢痕組織 ，然後將實驗室繁殖出來的幹細胞膠合在傷眼上 。

Researchers followed the patients for an average of three years and some as long as a decade. More than three-quarters regained sight after the transplant. An additional 13 per cent were considered a partial success. Though their vision improved, they still had some cloudiness in the cornea.

治療後的研究者對患者進行了隨訪 。隨訪時間為：其中一些患者平均三年 ，另一些患者多達十年 。 隨訪發現 ，超過四分之三的患者在移植後重新獲得了視力 。另外有13% 的患者被認為部分治愈 ，即其視力雖然得到改善 ，但角膜上仍然有一些雲翳妨礙視力 。

Patients with superficial damage were able to see within one to two months. Those with more extensive injuries took several months longer.

淺表損傷的患者在一兩個月內即能視物 ，而損傷更為廣泛的患者則需幾個月時間 。

The approach would not help people with damage to the optic nerve or macular degeneration, which involves the retina. Nor would it work in people who are completely blind in both eyes, because doctors need at least some healthy tissue that they can transplant.

該方法並不能幫助涉及視網膜的視神經損傷或黃斑部退化患者 ，對雙眼全盲的患者也無效 ，因為醫生說至少需要可供移植的健康細胞 。

Adult stem cells, which are found around the body, are different from embryonic stem cells, which come from human embryos and have stirred ethical concerns because removing the cells requires destroying the embryos.

成年人的幹細胞雖可在全身發現 ，但與胚胎幹細胞不同 ，後者來自人類晶胚 。晶胚的使用涉及到倫理問題 ，因為從晶胚移取細胞會徹底毀掉晶胚本身 。

Dr Sophie Deng, a cornea expert at the UCLA's Jules Stein Eye Institute, said the biggest advantage was that the Italian doctors were able to expand the number of stem cells in the lab. This technique is less invasive than taking a large tissue sample from the eye and lowers the chance of an eye injury.

加州大學洛杉磯分校Jules Stein眼研究所角膜專家Sophie Deng博士說本研究最大的優勢是 ：意大利的醫生們能夠在實驗室裏繁殖幹細胞 。比起從眼睛提取大組織樣本來說 ，本技術少有侵入性 ，從而降低了對其中一眼的損傷 。

'The key is whether you can find a good stem cell population and expand it,' she said.

“關鍵在於 ：你能不能找到好的幹細胞群然後加以繁殖 。”她說 。