Adsorption and carbonylation of plasma proteins by dialyser membrane material: in vitro and in vivo proteomics investigations.

BACKGROUND: Protein carbonylation is an irreversible and not reparable reaction which is caused by the introduction into proteins of carbonyl derivatives such as ketones and aldehydes, generated from direct oxidation processes or from secondary protein reaction with reactive carbonyl compounds. Several studies have demonstrated significantly increased levels of reactive carbonyl compounds, a general increase in plasma protein carbonyls and carbonyl formation on major plasma proteins in blood from uremic patients, particularly those undergoing chronic haemodialysis. MATERIALS AND METHODS: In the present preliminary study, we first assessed by an in vitro filtration apparatus the possible effects of different materials used for haemodialysis membranes on protein retention and carbonylation. We employed hollow fiber minidialyzers of identical structural characteristics composed of either polymethylmethacrylate, ethylenevinyl alcohol, or cellulose diacetate materials. Protein Western Blot and SDS-PAGE coupled to mass spectrometry analysis were applied to highlight the carbonylated protein-binding characteristics of the different materials. We also investigated in vivo protein carbonylation and carboxy methyl lisine-modification in plasma obtained before and after a haemodialysis session. RESULTS: Our data underline a different capability on protein adsorption associated with the different properties of the filter materials, highlighting the central buffering and protective role of serum albumin. In particular, polymethylmethacrylate and cellulose diacetate showed, in vitro, the highest capacity of binding plasma proteins on the surface of the hollow fiber minidialyzers. CONCLUSIONS: The present study suggests that biomaterials used for fabrication of haemodialysis membrane may affect the carbonyl balance in chronic uremic patients.

[Use of oral hypoglycemic agents in patients with chronic kidney failure]. / Farmaci ipoglicemizzanti orali nei pazienti con insufficienza renale cronica.

Type 2 diabetes mellitus is one of the most common disease worldwide. Diabetes mellitus is expected to affect over 380 million people by 2025 and one third of these patients will develop chronic kidney disease (CKD). There are many categories of hypoglycemic agents available for treatment of type 2 diabetes mellitus: sulphounilureas, glinides, biguanides, thiazolidinediones, alpha-glucosidase inhibitors, and the new brand incretines. In nephropatic patients with CKD stage I-II, any hypoglycemic agent can be used: the choice must be linked to a careful evaluation of potential risk and benefit. In CKD stage III to V, conversely, some drugs are not recommended while other agents can be used with dose reduction due to risk of hypoglycemia. In these patients the early use of insulin may be indicated. The target of this review is to evaluate evidences about the possible use of hypoglycemic agents in patients affected by diabetes and CKD stage III-V.