15/ 🧅Cutting onions ➡️ crying b/c of multiple enzymatic reactions in the air
🧅Allinase converts a released sulfoxide to
sulfenic acids, which rearrange to thiosulfinates
🧅Lachrymatory factor synthase converts thiosulfinates to propanethial-S-oxide (=source of onion-crying)
Thank you for reading and happy cooking!
Cc the legendary @Nigella_Lawson, who might find this interesting.
Correcting a small error in the summary tweet:
Propanethial-S-oxide is derived from sulfenic acids by lachrymatory factor synthase, not from thiosulfinates.
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2️⃣ I ❤️ the way he zooms in on individual stories and then zooms out. One chapter he’s in a ramshackle hut in rural Haiti, the next he’s building Haiti’s first neurology residency or meditating on the sociocultural basis for global health inequities
3️⃣ Through the stories he tells he actually manages to teach a decent bit of neurology (whether intentional or not)
1/🧵
Why does Wenckebach AV nodal block (aka Mobitz type 1) present with progressive prolongation of the PR interval and eventually a non-conducted P wave?
3/ The pattern Wenckebach observed corresponds exactly w/ the progressive PR prolongation, followed by a non-conducted P wave, that characterizes what we call “Wenckebach” heart block.
💥 Amazingly, he observed this BEFORE the AV node was discovered.
3/ This question had major implications for the nascent field of anesthesiology.
Some practitioners began to use curare alone during surgery, without sedation, believing that curare adequately sedated patients in addition to paralyzing them.