Synthesis, characterization, and biomedical evaluation of ethylene-bridged tetra-NHC Pd(ii), Pt(ii) and Au(iii) complexes, with apoptosis-inducing properties in cisplatin-resistant neuroblastoma cells.

Synthesis and characterization of the first two cyclic ethylene-bridged tetradentate NHC ligands, with an unsaturated (imidazole) and saturated backbone (2-imidazoline), are described. Complexes of both ligands containing palladium(ii) have been obtained. For platinum(ii) and gold(iii), only the unsaturated tetracarbene complexes could be isolated. The attempts to synthesize a methylene-bridged 2-imidazoline macrocycle are also described. Furthermore, a novel bisimidazolinium ligand precursor and its open-chain PdII and PtII tetracarbene complexes are obtained. Finally, it is shown that the unsaturated gold(iii) tetracarbene is able to induce apoptosis in malignant SK-N-AS neuroblastoma cells via the mitochondrial and ROS pathway and overcomes resistance to cisplatin in vitro.

Short- and long-term outcome after carotid artery stenting with neuroprotection: single-center experience within a prospective registry.

BACKGROUND: Carotid artery stenting is an alternative method to surgical endarterectomy for treatment of carotid artery stenosis. METHODS AND RESULTS: Three hundred and seventy-one consecutive patients (71+/-9 years) undergoing 405 carotid artery interventions at a single cardiologic center were studied prospectively within a therapy registry. In general, the interventional procedure was performed using neuroprotective devices to prevent distal embolization. Stents were used routinely whenever possible. Independent neurological assessment took place prior to and after carotid stenting. The neurological event rate was assessed in the early (<30 days) and late post interventional period. In asymptomatic patients, 286 interventions were done with a 30-day stroke rate of 1.3% (ipsilateral 1.0%). In symptomatic patients, strokes occurred in a significantly (p<0.005) higher rate of 5.0% after 119 interventions (all ipsilateral). At long-term follow-up (mean 728+/-548 days) additional strokes occurred ipsilateral to the side of carotid intervention in 0.4% of asymptomatic patients (1.7% of symptomatic patients); contralateral strokes were seen at long-term follow-up in 1.1% of asymptomatic (1.7% of symptomatic) patients. Due to their comorbidities, 1.6% of patients died early, and an additional 11.1% late after carotid stenting. CONCLUSION: Carotid artery stenting with the general use of neuroprotective devices yields acceptable shortterm results with respect to neurological events. Asymptomatic patients have significantly less periprocedural strokes than symptomatic patients. Neurological events during long-term follow-up are rare, in particular ipsilateral to the side of carotid stenting. Thus, carotid artery stenting with neuroprotection is a safe method for carotid revascularization, with acceptable periprocedural events, particularly in asymptomatic patients, and a good long-term neurologic outcome.