Recent Advances in Visualizing Vulnerable Plaque: Focus on Noninvasive Molecular Imaging

Traditional imaging methods in atherosclerosis have focused primarily on anatomic information. Imaging approaches that visualize molecular targets rather than anatomic structures may emphasize biologic aspects of atherosclerosis. Molecular imaging of atherosclerotic lesions has become a crucial experimental tool and is now emerging in the clinical arena. In this review, we briefly highlight the rationale and fundamental principles of molecular imaging. We then discuss the promising imaging modalities, along with their potential limitations, and the molecular targets being investigated in experimental research. Finally, we summarize the most important clinical studies recently performed in humans.     

Posterior box isolation as an adjunctive ablation strategy with the second-generation cryoballoon for paroxysmal atrial fibrillation: a comparison with standard cryoballoon pulmonary vein isolation

Journal of Interventional Cardiac Electrophysiology - The purpose of the study was to evaluate the impact of left atrial posterior wall isolation (LAPWI) in addition to pulmonary vein isolation...     

Effect of fluvoxamine on the pharmacokinetics of roflumilast and roflumilast N-oxide

OBJECTIVE: To investigate the effects of steady-state dosing of fluvoxamine, an inhibitor of cytochrome P450 (CYP) 1A2 and CYP2C19, on the pharmacokinetics of roflumilast, an oral, once-daily phosphodiesterase 4 (PDE4) inhibitor and its pharmacodynamically active metabolite roflumilast N-oxide. METHODS: In an open-label, non-randomised, one-sequence, two-period, two-treatment crossover study, 14 healthy subjects received a single oral dose of roflumilast 500 microg on study day 1. After a 6-day washout period, repeated doses of fluvoxamine 50 mg once daily were given from days 8 to 21. On day 15, roflumilast 500 microg and fluvoxamine 50 mg were taken concomitantly. Percentage ratios of test/reference (reference: roflumilast alone; test: roflumilast plus steady-state fluvoxamine) of geometric means and their 90% confidence intervals for area under the plasma concentration-time curve, maximum plasma concentration (roflumilast and roflumilast N-oxide) and plasma clearance of roflumilast were calculated. RESULTS: Upon co-administration with steady-state fluvoxamine, the exposure to roflumilast as well as roflumilast N-oxide increased by a factor of 2.6 and 1.5, respectively. Roflumilast plasma clearance decreased by a factor of 2.6, from 9.06 L/h (reference) to 3.53 L/h (test). The combined effect of fluvoxamine co-administration on roflumilast and roflumilast N-oxide exposures resulted in a moderate (i.e. 59%) increase in total PDE4 inhibitory activity. CONCLUSION: Co-administration of roflumilast and fluvoxamine affects the disposition of roflumilast and its active metabolite roflumilast N-oxide most likely via a potent dual pathway inhibition of CYP1A2 and CYP2C19 by fluvoxamine. The exposure increases observed for roflumilast N-oxide are suggested to be attributable to CYP2C19 co-inhibition by fluvoxamine and thus, are not to be expected to occur when roflumilast is co-administered with more selective CYP1A2 inhibitors.     

Graphene supports in vitro proliferation and osteogenic differentiation of goat adult mesenchymal stem cells: potential for bone tissue engineering

Current treatments for bone loss injuries involve autologous and allogenic bone grafts, metal alloys and ceramics. Although these therapies have proved useful, they suffer from inherent challenges, and hence, an adequate bone replacement therapy has not yet been found. We hypothesize that graphene may be a useful nanoscaffold for mesenchymal stem cells and will promote proliferation and differentiation into bone progenitor cells. In this study, we evaluate graphene, a biocompatible inert nanomaterial, for its effect on in vitro growth and differentiation of goat adult mesenchymal stem cells. Cell proliferation and differentiation are compared between polystyrene‐coated tissue culture plates and graphene‐coated plates. Graphitic materials are cytocompatible and support cell adhesion and proliferation. Importantly, cells seeded on to oxidized graphene films undergo osteogenic differentiation in fetal bovine serum‐containing medium without the addition of any glucocorticoid or specific growth factors. These findings support graphene's potential to act as an osteoinducer and a vehicle to deliver mesenchymal stem cells, and suggest that the combination of graphene and goat mesenchymal stem cells provides a promising construct for bone tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.     

Pharmacokinetic evaluation of roflumilast

INTRODUCTION: Roflumilast is a selective PDE4 inhibitor recently approved for oral, once-daily treatment of severe chronic obstructive pulmonary disease (COPD). Clinical trials have demonstrated the effect of roflumilast on reducing exacerbation frequency and improving lung function in COPD, while its mode of action may offer the potential to target the inflammatory processes underlying COPD. Roflumilast is, therefore, an important addition to current therapeutic options. It is catalyzed by cytochrome P450 (CYP) 1A2 and 3A4 to its active metabolite, roflumilast N-oxide, which accounts for > 90% of roflumilast total PDE4 inhibitory activity. AREAS COVERED: This article reviews the pharmacokinetics of roflumilast and considers the effects of co-administration with CYP inhibitors or inducers, and other medications commonly used in patients with COPD, on the pharmacokinetics of roflumilast and roflumilast N-oxide. EXPERT OPINION: Roflumilast has novel anti-inflammatory activity in COPD that provides the physician with a treatment option beyond bronchodilation. It can be co-administered with many medications commonly used by patients with COPD and its anti-inflammatory activity provides incremental benefits on top of existing therapies. Future research will further elucidate the impact of roflumilast on COPD and beyond, while alternative dosing regimens may offer a means to ameliorate transient tolerability issues.