[Preventing interruptions during the administration of medicines]. / Administration du médicament, prévenir les interruptions de tâches.

The medication use pathway is a complex process with a high risk of error, all the more so if it is interspersed with interruptions. Interruptions during care procedures are a real problem which can result in serious adverse events. A legal frame obliges the health institutions to secure the administration of medicines. This priority objective is translated by risks assessments, tools of self-assessment, audits, corrective actions, which allow a raising awareness of the professionals to the risks associated to medicines.

Free radical generation of protease-resistant prion after substitution of manganese for copper in bovine brain homogenate.

The exchange between copper and seven transition metals is studied in a bovine brain obex homogenate according to the redox status of the medium. In reductive conditions, almost all the studied metals can substitute for copper when it is in the reduced form Cu+. This substitution is reversible, since copper uptake as Cu++ is restored in an oxidizing medium but only Co++, Ni++ and Mn++, in this decreasing order, can substitute perfectly for copper in bovine brain homogenate. To study free radical effects on bovine brain proteins, at first a copper substitution was processed in order to inhibit superoxide dismutase-like protective properties against free radicals in copper metalloproteins. Manganese was selected since a brain copper decrease correlated with a manganese increase is well-known in transmissible spongiform encephalopathies. Results for bovine brain homogenate, initially negative in the Western blot Prionics test, indicate that the substitution of manganese for copper in a reducing medium and exposure to UVA-induced free radicals produce proteinase K resistant prion. These findings suggest that an impairment in brain metal homeostasis leading to oxidative abnormalities may be involved in transmissible spongiform encephalopathies.