METHODS	Fifty ADPPs and fifty healthy adult volunteers ( HAVs ) whose ages , gender and others were matched with the ADPPs were enrolled in a randomized controlled study , in which concentrations of nitric oxide ( NO ) , vitamin C ( VC ) , vitamin E ( VE ) and beta-carotene ( beta-CAR ) in plasma as well as concentration of lipoperoxide ( LPO ) , and activities of superoxide dismutase ( SOD ) , catalase ( CAT ) , glutathione peroxidase ( GPX ) and acetylcholinesterase ( AChE ) in erythrocytes were determined by spectrophotometric analytical methods .\