Crystal arthropathy is a class of joint disorder (called "arthropathy"), which acid is characterized by accumulation of tiny crystals in one or more joints. Polarizing microscopy and application of other crystallographic techniques have improved identification of different microcrystals including monosodium urate, what is the heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula CHNO?
Uric acid
Title: Uric acid
Passage: Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula CHNO.  It forms ions and salts known as urates and acid urates, such as ammonium acid urate.  Uric acid is a product of the metabolic breakdown of purine nucleotides, and it is a normal component of urine.  High blood concentrations of uric acid can lead to gout and are associated with other medical conditions including diabetes and the formation of ammonium acid urate kidney stones.
Title: Tophus
Passage: A tophus (Latin: "stone", plural tophi) is a deposit of uric acid crystals, in the form of monosodium urate crystals, in people with longstanding hyperuricemia (high levels of uric acid in the blood).  Tophi are pathognomonic for the disease gout.  Most people with tophi have had previous attacks of acute arthritis, eventually leading to the formation of tophi.  Chronic tophaceous gout is known as Harrison Syndrome.
Title: Crystal arthropathy
Passage: Crystal arthropathy is a class of joint disorder (called "arthropathy") that is characterized by accumulation of tiny crystals in one or more joints. Polarizing microscopy and application of other crystallographic techniques have improved identification of different microcrystals including monosodium urate, calcium pyrophosphate dihydrate, calcium hydroxyapatite, and calcium oxalate.
Uric acid Crystal arthropathy