How do blood transfusions work? - Bill Schutt

譯者: Lilian Chiu 審譯者: Helen Chang

In 1881, doctor William Halsted rushed to help his sister Minnie,

1881 年，

威廉·哈斯泰德醫生趕著 要去幫助他的妹妹米妮，

who was hemorrhaging after childbirth.

她生完孩子之後大量出血。

He quickly inserted a needle into his arm,

他很快地將一根針插入他的手臂，

withdrew his own blood, and transferred it to her.

將他自己的血液抽出來輸送給她。

After a few uncertain minutes, she began to recover.

經過充滿不確定性的 幾分鐘之後，她開始恢復。

Halsted didn’t know how lucky they’d gotten.

哈斯泰德並不知道他們有多幸運。

His transfusion only worked because he and his sister

他的輸血能夠成功， 只因為他和他妹妹

happened to have the same blood type—

剛好血型相同——

something that isn’t guaranteed, even among close relatives.

即便是很親的親人， 也無法保證血型一定會相同。

Blood types hadn’t been discovered by Halsted’s time,

在哈斯泰德的時代， 還沒有發現血型，

though people had been experimenting with transfusions for centuries—

不過數世紀來 人類一直在試驗輸血——

mostly unsuccessfully.

大部分都沒成功。

In 1667, a French physician named Jean-Baptiste Denis

1667 年，法國醫生尚巴蒂斯特·迪尼

became the first to try the technique on a human.

是第一在人類身上 測試輸血技術的人。

Denis transfused sheep’s blood into Antoine Mauroy,

迪尼把羊血輸給安東·苗瓦，

a man likely suffering from psychosis,

可能得了精神病的病人，

in the hopes that it would reduce his symptoms.

希望輸血能減輕他的症狀。

Afterward, Mauroy was in good spirits.

之後，苗瓦的精神很好。

But after a second transfusion, he developed a fever,

但在第二次輸血之後， 他開始發燒，

severe pain in his lower back, intense burning in his arm,

他的下背劇烈疼痛， 手臂有嚴重的灼燒感，

and he urinated a thick, black liquid.

還尿出了黑色的濃稠液體。

Though nobody knew it at the time,

當時沒有人知道，

these were the signs of a dangerous immune response unfolding inside his body.

但這些都是徵兆，表示他體內 開始出現了很危險的免疫反應的。

This immune response starts  with the production of proteins

這種免疫反應一開始會產生 一種蛋白質，稱為抗體，

called antibodies,

which distinguish the body’s own cells from intruders.

抗體能將身體本身的細胞 和入侵細胞區別開來。

They do so by recognizing the foreign proteins, or antigens,

它們的做法是從 入侵細胞的細胞膜中

embedded in an intruder’s cell membrane.

辨視出外來的蛋白質或抗原。

Antibodies latch onto the antigens,

抗體會抓住抗原，

signaling other immune cells to attack and destroy the foreign cells.

通知其他免疫細胞 去攻擊並摧毀外來細胞。

The destroyed cells are flushed from the body in urine.

被摧毀的細胞會 透過尿液被沖出身體。

In extreme cases, the massive break down of cells

在極端的案例中，細胞大量崩解

causes clots in the bloodstream that disrupt the flow of blood to vital organs,

會造成血流栓塞， 阻斷送往重要器官的血液，

overload the kidneys, and cause organ failure.

導致腎臟負荷過重， 因而造成器官衰竭。

Fortunately, Denis’s patient survived the transfusion.

幸運的是，迪尼的病人 撐過了這次輸血。

But, after other cross-species transfusions proved fatal,

但，證明跨物種輸血會致命之後，

the procedure was outlawed across Europe,

這種療法在歐洲各地被法律禁止，

falling out of favor for several centuries.

失寵了數個世紀。

It wasn’t until 1901 that Austrian physician Karl Landsteiner

直到 1901 年，奧地利醫生

卡爾·蘭德施泰納發現了血型。

discovered blood types,

the crucial step in the success of human to human blood transfusions.

這是人對人輸血 能夠成功的關鍵步驟。

He noticed that when different types were mixed together, they formed clots.

他注意到當不同的血型 混合在一起時就會形成凝塊。

This happens when antibodies latch on to cells with foreign antigens,

當抗體抓住有外來抗原的細胞時 就會發生這個現象，

causing blood cells to clump together.

造成血細胞凝結成塊。

But if the donor cells are the same blood type as the recipient’s cells,

但，如果捐血者的血型 和接收者相同，

the donor cells won’t be flagged for destruction, and won’t form clumps.

捐血者的細胞不會被標記為 摧毀目標，因此不會形成凝塊。

By 1907,

到了 1907 年，

doctors were mixing together small amounts of blood before transfusing it.

醫生會在輸血之前 先將少量的血液混合。

If there were no clumps, the types were a match.

如果沒有凝塊，血型就相符。

This enabled them to save thousands of lives,

這讓他們得以拯救數千條人命，

laying the foundation for modern transfusions.

為現代輸血奠定基礎。

Up to this point, all transfusions had occurred in real time,

一直到這個時點， 所有的輸血都要即時進行，

directly between two individuals.

直接由一個人輸給另一個人。

That’s because blood begins to clot almost immediately

那是因為只要血液一接觸到空氣，

after coming into contact with air—

幾乎馬上就會凝結——

a defense mechanism to prevent excessive blood loss after injury.

這是一種防禦機制， 預防受傷時大量失血。

In 1914, researchers discovered that the chemical sodium citrate

1914 年，研究者發現 化學物質檸檬酸鈉

stopped blood coagulating by removing the calcium necessary for clot formation.

能夠將形式凝塊所需要的鈣 除去，阻止血液凝結。

Citrated blood could be stored for later use—

加入檸檬酸的血液可以 儲存起來，後續再使用——

the first step in making large scale blood transfusions possible.

這是讓大規模輸血 成為可能的第一步。

In 1916, a pair of American scientists found an even more effective anticoagulant

1916 年，兩位美國科學家

發現了更有效的抗凝血劑，

called heparin, which works by deactivating enzymes that enable clotting.

叫做肝磷脂，它能夠將 促成凝結的酵素去活性化。

We still use heparin today.

現今我們都還在用肝磷脂。

At the same time,

同時，

American and British researchers developed portable machines

美國和英國的研究者 開發出了攜帶式的器材，

that could transport donor blood onto the battlefields of World War I.

能夠將捐血者的血液運送到 第一次世界大戰的戰場上。

Combined with the newly-discovered heparin,

結合新發現的肝磷脂，

medics safely stored and preserved liters of blood,

軍醫便能夠安全地儲存 和保存數公升的血液，

wheeling it directly onto the battlefield to transfuse wounded soldiers.

用車運送到戰場上， 輸血給受傷的士兵。

After the war, this crude portable box would become the inspiration

戰後，這種簡陋的可攜式盒子 變成了靈感來源，

for the modern-day blood bank, a fixture of hospitals around the world.

後來才會出現全世界醫院 必備的現代血庫。