時差N小時:血型不是問題

Yael: I just read about an exciting technique.Researchers found a way to convert types A and Bblood into type O blood—the type that can betransfused into any patient. This advance could helpavoid blood shortages in the future.

雅艾爾：我剛剛讀了一條振奮人心的技術。研究人員找到了一種可以把A型、B型血轉變?yōu)镺型血的方法。而O型血可以輸給任何病人。這項先進的技術能夠避免出現缺血的情況。

Don: Wow, that is exciting. But what makes type Oblood so special?

唐：哇，太振奮人心了。但為什么O型血這么特殊呢?

Yael: Blood types result from different carbohydrates, called antigens, on the surface of humanblood cells. Your blood "type" denotes the kinds of antigens you have on the surface of yourcells. People with type A blood have A antigens; those with type B have B antigens. If you haveboth kinds of antigens, you're type AB; if you have neither one, you're type O.

雅艾爾：血型因不同的碳水化合物而產生，這種關鍵的碳水化合物就是抗原，它長在人體血細胞的表面。你的血型表示你的血細胞表面有哪種抗體。A血型的人有A抗體;B血型的人有B抗體。如果你有A和B兩種抗體，那你就是AB血型的人;如果二者都沒有，那你就是O型血了。

Your immune system recognizes the antigens on your blood as "self", but attack cells with"foreign" antigens. So if you ever need a blood transfusion, it's important that you only receiveblood compatible with your own type.

免疫系統把血液中的這些抗體認作"自己人"，卻會攻擊那些帶有"外來"抗體的細胞。因此，如果你需要輸血時，你只能接受與自己血型相同的血，這很重要。

Don: I see. So if a type A person receives type B or AB blood, her immune system will see theB-antigens as foreign, and attack the donor blood cells?

唐：我明白了。所以如果A型血的人接受了B型血或者AB型血，她的免疫系統會視B抗體為外來者，于是就會攻擊供體的血細胞。

Yael: Exactly. But type O is called the "universal donor" since it doesn't have any antigensthat would set off the body's defense system.

雅艾爾：正是如此。O型血之所以被稱為"萬能血"，是因為它沒有任何抗體，不會和身體的防衛(wèi)系統相抵觸。

A team of Danish scientists has identified enzymes that remove the A and B antigens fromblood cells. The enzymes, which were extracted from a bacteria and a fungus, essentiallychange any donated blood into type O.

一個丹麥科學家小組已經找到了一種可以消除細胞中A、B抗體的酶。這種酶是從一種細菌和真菌中提取出來的, 可以把獻血者的血型完全變成O型。

Clinical trials are underway to test whether the treated blood is safe and effective. If so, thetechnology could help save lives, since type O blood is such a precious commodity.

臨床試驗正在測試這種轉化后的血是否安全有效。如果沒什么問題，這項技術將挽救不少性命，因為O型血確實很緊缺。