WILTIMS #103: Stars, wings and licorice

TIL: The prefix "sidero-" is confusing. In Latin it relates to the stars, as in sidereal time (telling time by the stars). But in Ancient Greek it means iron, as in sideromancy (divination by watching the burning of straw dropped on red-hot iron). In biochemistry, sidero- is also used in words describing iron containing molecules such as the precursors to heme, the iron containing part of hemoglobin.

Sticking with the etymological theme, pteroylpentaglutamate contains the prefix ptero- for wing, as in pterodactyl. This is because pteridine, the molecular building block of pteroylpentaglutamate, is also the precursor to the dyes responsible for the striking color of butterfly wings.

Consumption of large amounts of licorice (the plant or black-colored candy, not Red Vines) inhibits 11-beta HSD2, an enzyme in the kidneys that converts cortisol to cortisone. This causes a buildup of cortisol which in high concentrations can stimulate the kidneys' response to aldosterone by mineralocorticoid receptors. This causes the kidneys to increase sodium and water retention and secrete excessive amounts of potassium, resulting in hypertension and hypokalemia, respectively.

Dandy–Walker syndrome is a congenital brain malformation involving the area of the brain around and within the cerebellum. It is named for Walter Dandy and Arthur Earl Walker, two consecutive chiefs of neurosurgery at Johns Hopkins.