A rapid and simple assay method for determining neuraminidase activity was investigated fluorometrically with 4-methylumbelliferyl-N-Ac-a-D-neuraminide as a substrate. The time required for performance was less than 3 hr and the activity could be simply measured with a fluorescent spectrophotometer. Neuraminidase activity in culture supernatant of MDCK cell infected with a small quantity of inf...

tometric procedures to within an average of 5% (CS) or 10% (CPT) and with the NADH fluorometric procedure for CS to within an average of 1% (Table 2). Precision, as indicated by the coefficient of variation (CV) for sample replicates, averaged 4.4% for the CS ABD-F assays and 1.7 and 2.3% for NADH fluorometric and spectrophotometric assays, respectively. CVs for CPT are 6% for both procedures a...

The fluorometric benzophenone procedure for diphenylhydantoin has been simplified by eliminating the need for preliminary extraction of plasma with an organic solvent. Assays are done directly on 0.2 ml of plasma by treating it with alkaline permanganate to form benzophenone, extracting the benzophenone with heptane, and then shaking the heptane layer with sulfuric acid and measuring the fluore...

BACKGROUND Magnetic resonance spectroscopy studies have suggested above-normal turnover of membrane phospholipids in brains of patients with schizophrenia. One possible explanation for these findings is increased activity of the phospholipid-catabolizing enzyme phospholipase A2 (PLA2). However, attempts to demonstrate higher PLA2 activity in the serum of subjects with schizophrenia have led to ...

Both fluorometric and microbiological measurements of urinary riboflavin excretion have served as a basis for evaluation of nutritional status, detection of deficiency states, measurement of physiological availability, and determination of daily requirements. Fluorometric assay methods have commonly followed three basic procedures; namely, (a) that of Najjar (l), based on the extraction of ribo...

The spreading of HIV infection still is a serious epidemic disease in the Asia, including Thailand, especially by transmission from mother to child and resistant HIV strains causing the tolerant drug treatment. Therefore, discovery of a new drug is the hope for curing resistant strains which need atomic resolution structure of target protein, reverse transcriptase. In this paper, we reported th...