A paramagnetic agent causing ochronotic arthropathy.
Magnetic resonance imaging (MRI) identified a paramagnetic substance in the hyaline cartilage of the hips and knees in a patient with ochronosis. Chemical studies characterized the paramagnetic agent as melanin. The free radicals contained in melanin were shown to initiate cytotoxicity. The loss of cartilage in ochronotic arthropathy now can be explained at the electron level using the superoxide theory of oxygen toxicity. Inappropriate metabolism of oxygen also may explain early cartilage degeneration in hemochromatosis, hemosiderosis, and Wilson's disease.
Norfray
J F
JF
MR Center Springfield, Ltd., IL 62701.
Klingler
W G
WG
Menon
I A
IA
Persad
S
S
Berger
P A
PA
Ainscough
M
M
D002358:Cartilage, Articular / Q000032:analysis / Q000473:pathology*; D005260:Female; D005609:Free Radicals / Q000009:adverse effects; D006621:Hip Joint / Q000032:analysis / Q000473:pathology; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis / Q000209:etiology*; D007719:Knee Joint / Q000032:analysis / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008280:Magnetics / Q000009:adverse effects*; D008297:Male; D008543:Melanins / Q000009:adverse effects* / Q000032:analysis; D008875:Middle Aged; D009794:Ochronosis / Q000175:diagnosis / Q000209:etiology*; D013131:Spine / Q000032:analysis / Q000473:pathology
D005609:Free Radicals; D008543:Melanins