No abstract is provided for this article.
Fully bioresorbable scaffolds (BRS) offer a revolutionary treatment approach within the field of interventional cardiology. Since BRS devices provide temporary mechanical support to the vessel wall and then subsequently disappear, the technology has the potential to overcome many of the safety concerns associated with metallic drug-eluting stents, such as late stent thrombosis, prevention of late lumen vessel enlargement, and difficulties with surgical revascularization and imaging artifact with multislice computed tomography [Bourantas CV et al. Int J Cardiol 2012; Serruys PW et al. Lancet 2009]. This article discusses the advances in BRS over the last 5 to 6 years.
This paper explores the potential of a new source of fly ash, deposited on the site of a coal-fired power plant in Ireland dating from 1985 to 1995, as a cement replacement material. A series of X-ray diffraction (XRD) analyses on binder samples with cement replacement levels of 0, 10, 25 and 35% was undertaken to determine the fly ash’s mineralogical composition and to determine its suitability as a supplemental cementitious material (SCM). The XRD results reveal a unique mineral composition with promising characteristics for enhancing the strength and durability of concrete. The experimental results were used to calibrate a thermodynamic model to predict changing phase assemblage and hydration behaviour over time and per replacement level. Thermodynamic models have been shown to give credible predictions of the long-term performance of cements, including SCMs. The initial experimental results’ thermodynamic modelling demonstrates the feasibility of this fly ash source as a sustainable alternative to traditional cement, paving the way for more eco-friendly construction. Ash deposits dating from 1995 to 2005 and from 2005 to the present will be presented in subsequent publications.
We studied the effect of acute inhalation of middle-tar cigarette smoke on airway goblet cell secretion in anesthetized guinea pigs. Secretion induced by a low dose of smoke (10 breaths diluted 1:10 in air) was blocked by either hexamethonium or by filtering out the particulate phase of the smoke. The response was partially inhibited by atropine but was not inhibited by propranolol, phentolamine, or capsaicin pretreatment. Cutting the nerve supply to the airways did not inhibit the response to low-dose smoke. In contrast, goblet cell secretion induced by a high dose of cigarette smoke (20 breaths undiluted) was inhibited by capsaicin pretreatment but not by autonomic receptor blockade nor by filtering out the particulate phase. Secretion induced by the vapor phase of the high dose of cigarette smoke was blocked by capsaicin pretreatment but was not inhibited by hexamethonium. We conclude that in guinea pig airways the particulate phase of low doses of smoke activates cholinergic nerves via stimulation of parasympathetic ganglia, whereas the vapor phase of high doses of smoke activates capsaicin-sensitive sensory nerves.
PAF has many inflammatory effects in the airways and closely mimics the pathophysiology of asthma. PAF is a potent stimulus to eosinophil accumulation and activation and may be involved in the eosinophilic inflammation which characterises asthma and airway hyperresponsiveness.
Background Long-term benefits of coronary stenosis treatment with an everolimus-eluting bioresorbable scaffold are unknown. Objectives This study sought to evaluate clinical and imaging outcomes 5 years after bioresorbable scaffold implantation. Methods In the ABSORB multicenter, single-arm trial, 45 (B1) and 56 patients (B2) underwent coronary angiography, intravascular ultrasound (IVUS), and optical coherence tomography (OCT) at different times. At 5 years, 53 patients without target lesion revascularization underwent final imaging. Results Between 6 months/1 year and 5 years, angiographic luminal late loss remained unchanged (B1: 0.14 ± 19 mm vs. 0.13 ± 0.33 mm; p = 0.7953; B2: 0.23 ± 0.28 mm vs. 0.18 ± 0.32 mm; p = 0.5685). When patients with a target lesion revascularization were included, luminal late loss was 0.15 ± 0.20 mm versus 0.15 ± 0.24 mm (p = 0.8275) for B1 and 0.30 ± 0.37 mm versus 0.32 ± 0.48 mm (p = 0.8204) for B2. At 5 years, in-scaffold and -segment binary restenosis was 7.8% (5 of 64) and 12.5% (8 of 64). On IVUS, the minimum lumen area of B1 decreased from 5.23 ± 0.97 mm2 at 6 months to 4.89 ± 1.81 mm2 at 5 years (p = 0.04), but remained unchanged in B2 (4.95 ± 0.91 mm2 at 1 year to 4.84 ± 1.28 mm2 at 5 years; p = 0.5). At 5 years, struts were no longer discernable by OCT and IVUS. On OCT, the minimum lumen area in B1 decreased from 4.51 ± 1.28 mm2 at 6 months to 3.65 ± 1.39 mm2 at 5 years (p = 0.01), but remained unchanged in B2, 4.35 ± 1.09 mm2 at 1 year and 4.12 ± 1.38 mm2 at 5 years (p = 0.24). Overall, the 5-year major adverse cardiac event rate was 11.0%, without any scaffold thrombosis. Conclusions At 5 years, bioresorbable scaffold implantation in a simple stenotic lesion resulted in stable lumen dimensions and low restenosis and major adverse cardiac event rates. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856)
