Mechanisms to explain the poor results of carotid artery stenting (CAS) in symptomatic patients to date and options to improve CAS outcomes

BackgroundCarotid artery stenting (CAS) is considered by many as an alternative to carotid endarterectomy (CEA) for the management of carotid artery stenosis. However, recent trials demonstrated inferior results for CAS in symptomatic patients compared with CEA. We reviewed the literature to evaluate the appropriateness of CAS for symptomatic carotid artery stenosis and to determine the pathogenetic mechanism(s) associated with stroke following the treatment of such lesions. Based on this, we propose steps to improve the results of CAS for the treatment of symptomatic carotid stenosis.MethodsPubMed/Medline was searched up to March 25, 2010 for studies investigating the efficacy of CAS for the management of symptomatic carotid stenosis. Search terms used were “carotid artery stenting,” “symptomatic carotid artery stenosis,” “carotid endarterectomy,” “stroke,” “recurrent carotid stenosis,” and “long-term results” in various combinations.ResultsCurrent data suggest that CAS is not equivalent to CEA for the treatment of symptomatic carotid stenosis. Differences in carotid plaque morphology and a higher incidence of microemboli and cerebrovascular events during and after CAS compared with CEA may account for these inferior results.ConclusionsCurrently, most symptomatic patients are inappropriate candidates for CAS. Improved CAS technology referable to stent design and embolic protection strategies may alter this conclusion in the future

Novel C-35 terpenoids from the Panamarian liverwort Plagiochila Moritziana

A new class of C-35 terpenoids is described from Hepaticae: plagiospirolide A and plagiospirolide B, two novel heptacyclic spiro-terpenes were isolated from the Panamanian liverwort Plagiochila moritziana Lindbg. & Gott. Structures were determined by MS, extensive NMR studies and X-ray crystallographic analysis. The compounds may be biosynthesized by condensation of a sesquiterpenoid and a diterpenoid unit in a Diels-Alder like reaction

Laser Vitreolysis for Vitreous Opacities: A Prospective Study

Aim: The aim of this study is to evaluate the efficacy and safety of a YAG laser vitreolysis procedure used to remove bothersome vitreous opacities/floaters. Methods: The prospective clinical study included 42 eyes of 35 patients (age 32-81 years) with vitreous opacities generating visual disturbances. All patients were treated using the Ellex - Ultra Q Reflex YAG laser and underwent a complete eye examination before the laser vitreolysis and at 1, 3 and 6 months after the intervention. Changes in corrected distance visual acuity (CDVA), central retinal thickness (CRT), intraocular pressure (IOP) and patient’s subjective perception of disturbances were analysed. Results: The average number of laser shots was 118 (6 - 310 shots), with a total average energy of 3.8 mJ per laser shot (2.2 - 9 mJ). The laser intervention was performed only once in a total of 31 eyes (73.8%), whereas it was necessary to perform the intervention twice in 10 cases (23.8%). No significant differences in CDVA were detected during the whole follow-up (p>0.40). No significant changes were found either in CRT (p>0.32). Concerning IOP (p<0.001), it was reduced significantly immediately after the intervention, returning to the pre-intervention level afterwards. The analysis of the responses to the questionnaire revealed that there was a mean improvement in subjective visual symptoms according to patients of 71%. No complications were detected in the sample during the follow-up. Conclusion: Laser vitreolysis is a minimally invasive treatment, allowing a complete or partial elimination of vitreous opacities and leading to alleviation of patient’s disturbances

Generic Fibrational Induction

This paper provides an induction rule that can be used to prove properties of data structures whose types are inductive, i.e., are carriers of initial algebras of functors. Our results are semantic in nature and are inspired by Hermida and Jacobs' elegant algebraic formulation of induction for polynomial data types. Our contribution is to derive, under slightly different assumptions, a sound induction rule that is generic over all inductive types, polynomial or not. Our induction rule is generic over the kinds of properties to be proved as well: like Hermida and Jacobs, we work in a general fibrational setting and so can accommodate very general notions of properties on inductive types rather than just those of a particular syntactic form. We establish the soundness of our generic induction rule by reducing induction to iteration. We then show how our generic induction rule can be instantiated to give induction rules for the data types of rose trees, finite hereditary sets, and hyperfunctions. The first of these lies outside the scope of Hermida and Jacobs' work because it is not polynomial, and as far as we are aware, no induction rules have been known to exist for the second and third in a general fibrational framework. Our instantiation for hyperfunctions underscores the value of working in the general fibrational setting since this data type cannot be interpreted as a set.Comment: For Special Issue from CSL 201