Determination of intracellular glutathione and glutathione disulfide using high performance liquid chromatography with acidic potassium permanganate chemiluminescence detection.

Measurement of glutathione (GSH) and glutathione disulfide (GSSG) is a crucial tool to assess cellular redox state. Herein we report a direct approach to determine intracellular GSH based on a rapid chromatographic separation coupled with acidic potassium permanganate chemiluminescence detection, which was extended to GSSG by incorporating thiol blocking and disulfide bond reduction. Importantly, this simple procedure avoids derivatisation of GSH (thus minimising auto-oxidation) and overcomes problems encountered when deriving the concentration of GSSG from 'total GSH'. The linear range and limit of detection for both analytes were 7.5 × 10(-7) to 1 × 10(-5) M, and 5 × 10(-7) M, respectively. GSH and GSSG were determined in cultured muscle cells treated for 24 h with glucose oxidase (0, 15, 30, 100, 250 and 500 mU mL(-1)), which exposed them to a continuous source of reactive oxygen species (ROS). Both analyte concentrations were greater in myotubes treated with 100 or 250 mU mL(-1) glucose oxidase (compared to untreated controls), but were significantly lower in myotubes treated with 500 mU mL(-1) (p < 0.05), which was rationalised by considering measurements of H(2)O(2) and cell viability. However, the GSH/GSSG ratio in myotubes treated with 100, 250 and 500 mU mL(-1) glucose oxidase exhibited a dose-dependent decrease that reflected the increase in intracellular ROS.

A comparison of the figure-of-eight method and water volumetry in measurement of hand and wrist size.

The purpose of this study was to develop a tape measure method to assess the size of the hand and wrist. This tape measure method was designed to be readily performed, easily administered, reliable, and valid compared with water volumetry. The study sample included 50 normal consenting volunteers. Two examiners measured each hand of each subject three times, alternating hands between measurements. In the second phase of the study, the same two examiners measured both hands of the subjects using the traditional water volumetry method. The intraclass correlation coefficients for intra- and interater reliability obtained were 0.99. Pearson product-moment correlation values between the figure-of-eight tape measure and the water volumetry method for the two examiners were 0.94 and 0.95, respectively. The figure-of-eight method demonstrated excellent reliability and concurrent validity compared with the water volumetry method. These results support the application of the figure-of-eight method as a reliable and valid evaluation tool for the assessment of hand and wrist size.