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　　In a heart bypass operation, surgeons typically remove a vein³ from a patient's leg and use it to replace blocked arteries⁴ that feed the muscles of the heart. But what if, instead of cutting open the patient's leg, the surgeon used an artificial blood vessel¹ that has been sitting in a hospital refrigerator? The new research suggests that day may soon come.

　　外科医生在心脏搭桥手术中的典型做法，是从病人的腿上取下一截静脉血管，来代替原来为心肌输送血液、但是被堵塞的动脉血管。但是，如果医生不是从病人腿上取血管，而是从冰箱里拿一根人造血管使用，结果如何？

　　The artificial blood vessels are made by coating a biodegradable, plastic mesh⁵ tube with human or animal muscle cells. The cells produce a protein structure shaped like the plastic tube, which dissolves.

　　这种血管是在能进行生物分解的塑料网管线上涂一层人类或动物的肌肉细胞。这些细胞产生出和塑料管同样形状的蛋白结构，而塑料管则分解了。

　　Shannon Dahl is co-founder of Humacyte, the North Carolina company that developed the artificial blood vessel. She explains that the next step is washing away the original muscle cells.

　　这项技术是北卡罗来纳州休马西特公司研发的。这家公司的共同创办人香农·达尔解释说，下一步是把原先涂上的肌肉细胞洗掉。

　　"So that what we're left with - the bioengineered vein - is just the proteins that the cell secreted⁶. This protein structure, the bioengineered vein, can be used in any human patient because the immunogenic part, the cells, have been removed," Dahl says.

　　她说：“因此我们最后留下来的，是生物工程血管，也就是这些细胞分泌的蛋白质。这些蛋白结构，也就是生物工程血管可以用在任何病人身上，因为具有免疫原性的细胞已经被除掉了。”

　　The material is considered immunogenic since the protein structure won't be recognized by the recipient⁷ as foreign material.

　　除掉免疫原性，就是指这种蛋白结构不会被排斥，因为接受移植的身体不会辨认出它是外来物质。

　　The artificial grafts⁸ resist bursting and tearing in lab tests, but the real question is how they perform when used on an actual patient.

　　这种人工血管在试验中可以防爆和防裂。但问题是，用在病人体内时，情况如何。

　　The research team implanted artificial vessels into a number of animals, doing heart bypass and other procedures. Alan Kypson, a surgeon at East Carolina University, did some of the implants⁹. A year later, the blood vessels were still performing well.

　　研究小组将人造血管用在几种动物搭桥手术和其它手术中。东卡罗来纳大学外科医生阿兰·吉普森说，手术一年之后，这些血管仍旧正常。

　　"It looked very similar, almost identical to the way it looked a year prior," Kypson says. "It didn't show any evidence of dilating¹⁰ or enlarging or calcifying¹¹. And they were open, most importantly. They were patent, meaning there was no obstruction¹² to blood flow in these bypasses."

　　“这些血管看来和一年前的样子几乎完全相同，没有显出任何扩张、变大或是钙化的情形。最重要的是，它们保持畅通。在搭桥部分，血液通行无阻。”

　　According to Kypson, the artificial blood vessel would have advantages in heart bypass surgery because it doesn't require removal of a vein from a patient's leg. That means less time on the operating table, less chance of infection, and less pain for the patient.

　　吉普森说，人造血管在心脏搭桥手术上有很多优点，因为不需要从病人腿上取血管了。这意味着，病人在手术台上的时间可以缩短。感染的可能性减少了，疼痛也减少了。

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