RESUMEN
Xanthine oxidase (XO) is an important enzyme with broad medical applications as detecting reagent in many diagnostic kits. In this study, buffalo liver xanthine oxidase (BLXO) was purified to homogeneity by acetone precipitation and chromatography on DEAE-cellulose and Sephacryl S-300 columns with a specific activity of 7.2 units / mg protein which represent 31.3 folds. The native molecular weight of the purified enzyme is 200 kDa and its subunit molecular weight was determined by SDS-PAGE to be 67 kDa. The isoelectric point (pI) value of BLXO isoenzyme is at pH 6.0 – 6.2. It displayed its pH optima at 7.6 and the Km value is 1.1 mM xanthine. FeCl2 increased the activity of BLXO while CuCl2, MnCl2 and ZnCl2 were found to be inhibitors of the purified enzyme. Allopurinol inhibits BLXO competitively and has one binding site on it with Ki value of 0.025mM. Abbreviations: BSA, Bovine serum albumin, XO, Xanthine oxidase, NBT, Nitroblue tetrazolium, PAGE, Polyacrylamide gel electrophoresis, PMS, Phenazine methosulphate, BLXO, Buffalo liver xanthine oxidase
RESUMEN
The aim of this work was to study the superior level of MRI and MR arthrography for the evaluation of the shoulder joint diseases. Sixty-five patients of different ages, occupations and different complaints and clinical suspicions were included in this study, 42 were subjected to plain MRI and 38 to MR arthrography and 15 were subjected to the two examinations. It was concluded that MRI with or without arthrography was the most available imaging modality for shoulder joint disease