The Solution Chemistry of Cu2+–tren Complexes Revisited: Exploring the Role of Species That Are Not Trigonal Bipyramidal

Potentiometric and spectrophotometric titrations indicate that aqueous solutions that contain equimolar amounts of Cu2+ and tren contain the HCuL3+, CuL2+ and CuL(OH)+ species and that their relative concentrations depend on the pH of the solution. The stability constants and the UV/Vis and EPR spectra of the three species have been determined. The position of the absorption maximum clearly corresponds to a trigonal bipyramidal (tbp) geometry for CuL2+, whereas for HCuL3+ and CuL(OH)+ there are also bands that could correspond to square pyramidal (sp) complexes, but the EPR spectra indicate that only HCuL3+ can be considered to be sp. When any of these species is mixed with an excess of acid, an intermediate is formed within the mixing time of the stopped-flow technique. This intermediate undergoes complete decomposition in a second slower step. Interestingly, the spectrum of this intermediate is typical of sp geometry. Kinetic studies on complex formation in general indicate that complexation occurs in a single step, although under certain conditions an additional step has been observed that probably corresponds to the conversion of CuL2+ to HCuL3+, and the spectral changes indicate that the process involves structural reorganization from tbp to sp geometry. DFT and TDDFT calculations have been carried out for the three stable species, as well as for species in a higher protonation state. The results indicate that CuL2+ exists as a species with tetradentate tren and tbp geometry, although a wide range of distortions between the ideal tbp geometry and a geometry closer to sp is possible with a very modest energy cost. The energy change associated with hydrolysis of one of the Cu– N bonds to give a species with tridentate tren was found to be slightly higher than that previously found for a related ligand, which contains a substituent at one of the terminal amino groups. For CuL(OH)+, the calculations suggest that an equilibrium exists between species with essentially the same energy but different geometries, each one of the species is closer to one of the ideal tbp and sp limits. For HCuL3+, the relevance of the sp geometry was confirmed by the calculations

Determinants of the access to remote specialised services provided by national sarcoma reference centres

BACKGROUND: Spatial inequalities in cancer management have been evidenced by studies reporting lower quality of care or/and lower survival for patients living in remote or socially deprived areas. NETSARC+ is a national reference network implemented to improve the outcome of sarcoma patients in France since 2010, providing remote access to specialized diagnosis and Multidisciplinary Tumour Board (MTB). The IGéAS research program aims to assess the potential of this innovative organization, with remote management of cancers including rare tumours, to go through geographical barriers usually impeding the optimal management of cancer patients. METHODS: Using the nationwide NETSARC+ databases, the individual, clinical and geographical determinants of the access to sarcoma-specialized diagnosis and MTB were analysed. The IGéAS cohort (n = 20,590) includes all patients living in France with first sarcoma diagnosis between 2011 and 2014. Early access was defined as specialised review performed before 30 days of sampling and as first sarcoma MTB discussion performed before the first surgery. RESULTS: Some clinical populations are at highest risk of initial management without access to sarcoma specialized services, such as patients with non-GIST visceral sarcoma for diagnosis [OR 1.96, 95% CI 1.78 to 2.15] and MTB discussion [OR 3.56, 95% CI 3.16 to 4.01]. Social deprivation of the municipality is not associated with early access on NETSARC+ remote services. The quintile of patients furthest away from reference centres have lower chances of early access to specialized diagnosis [OR 1.18, 95% CI 1.06 to 1.31] and MTB discussion [OR 1.24, 95% CI 1.10 to 1.40] but this influence of the distance is slight in comparison with clinical factors and previous studies on the access to cancer-specialized facilities. CONCLUSIONS: In the context of national organization driven by reference network, distance to reference centres slightly alters the early access to sarcoma specialized services and social deprivation has no impact on it. The reference networks' organization, designed to improve the access to specialized services and the quality of cancer management, can be considered as an interesting device to reduce social and spatial inequalities in cancer management. The potential of this organization must be confirmed by further studies, including survival analysis

DERMATITE ATOPIQUE ET ALLERGIE ALIMENTAIRE (ETUDE DU DEVENIR DE 27 ENFANTS)

NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

Cancer de l’ovaire révélé par des métastases cutanées et une lymphangite carcinomateuse mammaires

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