20 Things You Didn't Know About... Blood
Blood
types aren't unique to humans: Dogs have more than a dozen.
2. ABO isn’t the only blood grouping
system, however. There are currently 33 systems recognized by the International
Society of Blood Transfusion, with monikers like Lutheran, Duffy, Hh/Bombay and
Ok.
3. Blood type refers to different
molecules on the surface of red blood cells. A mismatch of these molecules
between donor and recipient can trigger a fatal immune reaction after a blood
transfusion, as the recipient’s body attacks the outsider blood.
4. But not all blood types matter
for all transfusions. Some variants are very rare, or exist only in certain
ethnic groups, so the danger of getting a mismatch is, for most people,
low.
5. The Junior blood type was formally
classified just two years ago when researchers pinpointed the molecule
responsible for it. The vast majority of people are Junior positive, but more
than 50,000 Japanese are Junior negative. For them, a mismatch can cause a
dangerous reaction.
6. Blood types aren’t unique to humans.
Dogs have more than a dozen, for example.
7. Before blood types were
discovered, doctors experimented with blood transfusions between humans and
animals. Spoiler: It didn’t go well.
8. In December 1667,
physician Jean-Baptiste Denis twice infused a man with calf’s blood in an
attempt to cure him of mental illness. After tolerating the first procedure,
the patient responded to the second, larger transfusion by vomiting, passing
black urine — never a good sign — and complaining of pain in his kidneys.
9. After suffering a third and final
transfusion, the man died. Denis went on trial for murder, but was acquitted
when it became clear the patient had been poisoned — not with blood, but with
arsenic.
10. Other doctors had orchestrated the
poisoning, fearing the procedure was morally dangerous, and wanting to make
sure Denis failed before he started a trend, according to historian Holly
Tucker’s book Blood Work.
11. Speaking of iffy practices, in 1892,
citizens of Exeter, R.I., exhumed the body of Mercy Brown, recently dead of
tuberculosis, and fed the ashes of her heart and liver to her sickly younger
brother. They believed she had become a vampire and was preying on him.
12. Such 19th-century New England vampire
panics coincided with tuberculosis outbreaks. The dead person’s family members
often got sick and died, suggesting supernatural interference to
townsfolk.
13. True blood eating, or hematophagy, is
practiced by about 14,000 insects, including the dreaded bedbug, scourge of the
mattress.
14. A sup of blood is referred to by
entomologists as a bloodmeal. Transparent young bedbugs turn ruby-red after
their first feed.
15. Being a bloodmeal’s no fun, but at
least it’s temporary. A more serious burden plagued the British royal family
until recently: hemophilia, a blood-clotting disorder. The mutation that caused
it arose spontaneously in Queen Victoria.
16. In 2009, researchers reported that the
“royal disease” was in fact quite rare. It was hemophilia B, which affects
about 1 in 25,000 males in the U.S. — that’s five times fewer sufferers than
hemophilia A.
17. The conclusion was drawn from an
analysis of the bones of the assassinated Romanov family of Russia, descended
from Victoria’s daughter Alice.
18. Today, hemophiliacs are treated with
regular infusions of the clotting factors their bodies are unable to make,
which are manufactured from donated blood.
19. Researchers are investigating ways to
insert functioning versions of the clotting factor gene into patients’ own
cells. In 2011, six hemophilia B patients were able to stop or decrease the
frequency of their usual injections thanks to gene therapy.
20. No one is proposing
gene therapy for a more common blood-based woe, however: the ice cream
headache. You’ll just have to learn to live with the pain, believed to be
caused by quick dilation of the brain’s anterior cerebral artery due to sudden
temperature changes in the mouth.
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