Permeability and Release of Decontaminating Agent Used in Cytotoxic Reconstitution Units: Diffusion of Hydrogen Peroxide in IV Bags

IntroductionOxidant agents used for top-decontamination in cytotoxic reconstitution units may spread into IV bags. The amount of hydrogen peroxide passing through the bags and its release have been evaluated using wrapped or unwrapped infusion bags made of three layers of polyolefin (FreeflexMethods3 experiments were carried out using 2 packages of 30 bags of polyolefin with (package A) or without (package B) overwrapping. A 43 min decontamination cycle with HResultsA linear calibration curve over the concentration range of 0.00–2.70 ppm was used prior to each analysis. The concentration of HConclusion/DiscussionThese results allow removing overwrapping for a lean production system, with an extemporaneous use. However, the graduate release of H

Automated assay of plasma bromide after a single deproteinization step

This study aimed to simplify the spectrophotometric fluorescein method for measuring plasma bromide, improve its reproducibility, and automate it. After major modifications of the method, we obtained an essentially linear calibration curve for plasma concentrations of bromide between 0 and 5.0 mmol/L. The intraassay CV for measuring bromide in the supernatants of deproteinized plasma samples (initial plasma concentrations 2.5-5.0 mmol/L) was as low as 0.5-1.0% (n = 9). When all the procedures were incorporated, including deproteinization and dilution of plasma, the intraassay CV was 2% at 2.5 mmol/L (n = 5) and 1% at 5.0 mmol/L (n = 5). The interassay CV for measuring bromide in plasma supernatants (initial plasma bromide concentration > 2.5 mmol/L) was 1%. Analytical recovery of bromide added to plasma was 99.1% +/- 2.5%. The new method is simpler and more reproducible than other spectrophotometric methods. Conditions for its automation are described.

Quantitative Computed Tomography in Measurement of Vertebral Trabecular Bone Mass

Measurement of bone mineral concentration (BMC) can be done by several modalities. Quantitative computed tomography (QCT) can be used for measurements at different sites and with different types of bone (trabecular-cortical). This study presents a modified method reducing the influence of fat. Determination of BMC was made from measurements with single-energy computed tomography (CT) of the mean Hounsfield number in the trabecular part of the L1 vertebra. The method takes into account the age-dependent composition of the trabecular part of the vertebra. As the amount of intravertebral fat increases with age, the effective atomic number for these parts decreases. This results in a non-linear calibration curve for single-energy CT. Comparison of BMC values using the non-linear calibration curve or the traditional linear calibration with those obtained with a pixel-by-pixel based electron density calculation method (theoretically better) showed results clearly in favor of the non-linear method. The material consisted of 327 patients aged 6 to 91 years, of whom 197 were considered normal. The normal data show a sharp decrease in trabecular bone after the age of 50 in women. In men a slower decrease was found. The vertebrae were larger in men than in women.