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They say what doesn’t kill you makes you stronger. But sometimes what makes you stronger can kill you, at least when it comes to blood clotting. Because the stickiness that allow platelets to heal your wounds also raises your risk of heart attack.
傳言殺而不死，則至更強。但有時候，至少血栓，是殺得死你的哦。因為血小板的粘性雖然可以治愈你的傷口，但同時也增加了心臟病的發病幾率。
All mammals use platelets to help prevent blood loss after traumatic injury. But birds don’t have ‘em, nor do reptiles or fish. Instead, these critters have blood cells called thrombocytes, which are about twice the size of platelets. But is bigger necessarily better when it comes to clotting? Scientists took thrombocytes from parakeets and put them to the test. The work appears in the journal Blood. [Alec A. Schmaier et al., "Occlusive thrombi arise in mammals but not birds in response to arterial injury: evolutionary insight into human cardiovascular disease"]
所有哺乳動物在受到外傷時都靠血小板止血。但是鳥類沒有血小板，爬行動物和魚類也沒有。然而，這些生物有一種叫做thrombocytes的血細胞,是血小板的2倍大。但是對于凝血來說，越大效果就一定更好嗎？對此，科學家從長尾鸚鵡體內提取thrombocytes進行測試。此項研究發表于《血液》雜志。
They focused their attention on birds because our feathered friends have a cardiovascular system much like our own, in that blood exerts pressure on walls of blood vessels.
科學家以鳥類作為研究對象的原因是，我們的長羽毛的朋友與我們的血管系統有相似之處：血液對血管內壁的施壓方式相同。
The results: parakeet thrombocytes don’t stick together like platelets do. They also don’t block blood flow in the birds’ arteries the same way that platelets do when they form clots in mice.
研究結果：長尾鸚鵡的thrombocytes不會像血小板那樣粘在一起，它們也不會像老鼠體內的血小板那樣在凝結時阻塞動脈內的血液流動。
Which means that mice may be more likely to survive a bloodletting-pecking. But birds are far less likely to suffer from the clot formation called economy class syndrome—despite being frequent fliers.
結論是，老鼠不懼放血，而鳥亦無視經濟艙綜合征——盡管它們總是飛來飛去。
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