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Curcuminoids are a group of compounds with a similar chemical backbone structure but containing different numbers of methoxy groups that have therapeutic potential due to their anti-inflammatory and anti-oxidant properties. They mainly bind to albumin in plasma. These findings influence their body disposition and biological activities. Spectroscopic analysis using site specific probes on human serum albumin (HSA) clearly indicated that curcumin (Cur), demethylcurcumin (Dmc) and bisdemethoxycurcumin (Bdmc) bind to both Site I (sub-site Ia and Ib) and Site II on HSA. At pH 7.4, the binding constants for Site I were relatively comparable between curcuminoids, while the binding constants for Site II at pH 7.4 were increased in order Cur , Dmc , Bdmc. Binding experiments using HSA mutants showed that Trp214 and Arg218 at Site I, and Tyr411 and Arg410 at Site II are involved in the binding of curcuminoids. The molecular docking of all curcuminoids to the Site I pocket showed that curcuminoids stacked with Phe211 and Trp214, and interacted with hydrophobic and aromatic amino acid residues. In contrast, each curcuminoid interacted with Site II in a different manner depending whether a methoxy group was present or absent. A detailed analysis of curcuminoids-albumin interactions would provide valuable information in terms of understanding the pharmacokinetics and the biological activities of this class of compounds.

The degree of oxidized cysteine (Cys) 34 in human serum albumin (HSA), as determined by high performance liquid chromatography (HPLC), is correlated with oxidative stress related pathological conditions. In order to further characterize the oxidation of Cys34-HSA at the molecular level and to develop a suitable analytical method for a rapid and sensitive clinical laboratory analysis, the use of electrospray ionization time-of-flight mass spectrometer (ESI-TOFMS) was evaluated. A marked increase in the cysteinylation of Cys34 occurs in chronic liver and kidney diseases and diabetes mellitus. A significant positive correlation was observed between the Cys-Cys34-HSA fraction of plasma samples obtained from 229 patients, as determined by ESI-TOFMS, and the degree of oxidized Cys34-HSA determined by HPLC. The Cys-Cys34-HSA fraction was significantly increased with the progression of liver cirrhosis, and was reduced by branched chain amino acids (BCAA) treatment. The changes in the Cys-Cys34-HSA fraction were significantly correlated with the alternations of the plasma levels of advanced oxidized protein products, an oxidative stress marker for proteins. The binding ability of endogenous substances (bilirubin and tryptophan) and drugs (warfarin and diazepam) to HSA purified from chronic liver disease patients were significantly suppressed but significantly improved by BCAA supplementation. Interestingly, the changes in this physiological function of HSA in chronic liver disease were correlated with the Cys-Cys34-HSA fraction. In conclusion, ESI-TOFMS is a suitable high throughput method for the rapid and sensitive quantification of Cys-Cys34-HSA in a large number of samples for evaluating oxidative stress related chronic disease progression or in response to a treatment.

Magnetic field-free measurements of the total cross sections for positron-neon and positron-argon scattering have been performed using an electrostatic high-brightness slow positron beam apparatus.

We proposed a technique for reconstructing bio-electric conductivity distribution from measured tangential magnet field data. That is, in the 2D ROI with an arbitrary depth two orthogonal tangential components of 3D current vector field were respectively estimated from the synthetically measured two tangential magnetic fields, from which the 2D conductivity distribution was estimated. To cope with inevitable measurement errors, a robust numerical solution was developed, in which the modification method and the regularization method were efficiently utilized. By performing this 2D reconstruction at each depth, 3D conductivity distribution could be estimated. As typical applications, pathological state and/or bio-electric conductive path can be evaluated by monitoring the temporal change of the reconstructed 3D conductivity distribution. The feasibility of this technique was briefly verified by reconstructing a conductivity distribution using simulated noise-filled magnetic field data, with resultant reconstruction indicating that the approach could provide a practical means for robustly reconstructing a conductivity distribution., Papers from the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 25-28 OCT 2001, Istanbul, Turkey. See also ADM001351 for entire conference on cd-rom.

The possibility was investigated of recovering platinum group metals from automotive catalysts by absorption on perovskite-type oxides. CaTiO3 and BaCeO3 were synthesised with metallic Pt and Pd in air at high temperature and the Pt and Pt contents determined by chemical analysis. The results showed that CaTiO3 absorbed both Pt and Pd, while BaCeO3 only absorbed Pt., The possibility was investigated of recovering platinum group metals from automotive catalysts by absorption on perovskite-type oxides. CaTiO3 and BaCeO3 were synthesised with metallic Pt and Pd in air at high temperature and the Pt and Pt contents determined by chemical analysis. The results showed that CaTiO3 absorbed both Pt and Pd, while BaCeO3 only absorbed Pt.