nitrophenols and Hepatitis-C--Chronic

The activity of the α-L-fucosidase (AFU) enzyme represents an excellent test for diagnosis of hepatocellular carcinoma (HCC) and fucosidosis recognized in inborn disorder of metabolism and increases the sensitivity of detection to 95.5% in patients with HCC. Therefore, the determination of the activity of AFU enzyme is very important and can be used as a screening tool for the early diagnosis of tumors for HCC patients. A simple, accurate, and sensitive potentiometric method was developed for measuring the activity of AFU. The method was based upon measuring the concentration of 2-chloro-4-nitrophenol (2-chloro-4-NP) using a 2-chloro-4-NP-rhodamine B ion pair in a PVC membrane sensor. The electrode shows a linear, reproducible, and stable potentiometric response with an anionic Nernstian slope of -51.13 ± 0.6 mV/decade over a wide range of concentrations 10(-5)-10(-2) M and a detection limit of 1.0 × 10(-6) M of 2-chloro-4-NP. The membrane exhibits a fast response time of 30 s, over a pH range of 4.0-6.5. The selectivity coefficients indicate excellent selectivity for 2-chloro-4-NP over a number of interfering species, e.g., chloride, nitrate, sulfate, chromate urea, albumin, glucose, uric acid, and total protein. The prepared sensor has been used successfully for the determination of 2-chloro-4-NP produced from the hydrolysis of 2-chloro-4-NP-α-L-fucopyranoside substrate. It was also applied for the determination α-L-fucosidase enzyme of 33 serum samples of healthy subjects and patients. The average recoveries ± RSD for the healthy subjects, cirrhosis of chronic hepatitis C and B, and HCC serum samples were 102.6 ± 1.01%, 101.5 ± 0.95%, and 100.1 ± 1.1%, respectively. The results obtained are in good agreement with those obtained by standard methods.

Topics: Adult; Aged; alpha-L-Fucosidase; Biosensing Techniques; Carcinoma, Hepatocellular; Female; Hepatitis C, Chronic; Humans; Limit of Detection; Male; Membranes, Artificial; Middle Aged; Nitrophenols; Polyvinyl Chloride; Potentiometry; Rhodamines; Young Adult

A low cost and accurate method for the detection and analytical determination of the activity of the enzyme alpha-L-fucosidase (AFU) was developed. The method was based upon measuring the fluorescence intensity of the complex ion associate of the ion associate of rhodamine-B and the compound 2-chloro-4-nitrophenol (RB(+)CNP(-)) at 580 nm in phosphate buffer (pH 5) against the reagent blank. The influence of the different parameters, e.g. pH, incubation time, temperature, 2-chloro-4-nitrophenol concentration, foreign ions and surfactants that control the fluorescence intensity of the produced ion associate was critically investigated. The correlation between the fluorescence activity of the enzyme AFU by the developed procedures and the standard method was positive and highly significant in patients and controls (r(2)=0.99, p<0.001). The developed method is simple and proceeds without practical artifacts compared to the standard method.

Topics: alpha-L-Fucosidase; Hepatitis B, Chronic; Hepatitis C, Chronic; Humans; Hydrogen-Ion Concentration; Ions; Nitrophenols; Reproducibility of Results; Rhodamines; Spectrometry, Fluorescence