Linking biofilm spatial structure to real-time microscopic oxygen decay imaging

Two non-destructive techniques, confocal laser scanning microscopy (CLSM) and planar optode (VisiSens imaging), were combined to relate the fine-scale spatial structure of biofilm components to real-time images of oxygen decay in aquatic biofilms. Both techniques were applied to biofilms grown for seven days at contrasting light and temperature (10/20°C) conditions. The geo-statistical analyses of CLSM images indicated that biofilm structures consisted of small (~100 µm) and middle sized (~101 µm) irregular aggregates. Cyanobacteria and EPS (extracellular polymeric substances) showed larger aggregate sizes in dark grown biofilms while, for algae, aggregates were larger in light-20°C conditions. Light-20°C biofilms were most dense while 10°C biofilms showed a sparser structure and lower respiration rates. There was a positive relationship between the number of pixels occupied and the oxygen decay rate. The combination of optodes and CLMS, taking advantage of geo-statistics, is a promising way to relate biofilm architecture and metabolism at the micrometric scale

Stent Fracture after Everolimus-Eluting Stent Implantation

Compared with bare-metal stents, drug-eluting stents (DES) have greatly reduced the risk of in-stent restenosis (ISR) by inhibiting neointimal growth. Nevertheless, DES are still prone to device failure, which may lead to cardiac events. Recently, stent fracture (SF) has emerged as a potential mechanism of DES failure that is associated with ISR. Stent fracture is strongly related to stent type, and prior reports suggest that deployment of sirolimus eluting stents (SES) may be associated with a higher risk of SF compared to other DES. Everolimus eluting stents (EESs) represent a new generation of DES with promising results. The occurrence of SF with EES has not been well established. The present paper describes two cases of EES fracture associated with ISR

Vascular access approach for structural heart procedures

Vascular access is an essential part of all interventional procedures whether coronary or structural. Over the last 15 to 20 years, in coronary interventions, traditional femoral access has been mostly replaced by the radial approach. Nonetheless, the femoral approach through both artery and vein is still the main approach for structural heart procedures. Over the last few years, femoral access has evolved from a puncture guided by anatomical references to more accurate ultrasound-guided approaches. The relatively recent introduction of interventions such as transcatheter aortic valve replacement has conditioned the use of large introducers and ultimately the need for specific hemostatic systems, above all, percutaneous closure devices. This manuscript reviews different anatomical concepts, puncture techniques, diagnostic assessments, and closure strategies of the main arterial and venous approaches for the diagnosis and treatment of different structural heart procedures

A mechanistic model (BCC-PSSICO) to predict changes in the hydraulic properties for bio-amended variably saturated soils

The accumulation of biofilms in porous media is likely to influence the overall hydraulic properties and, consequently, a sound understanding of the process is required for the proper design and management of many technological applications. In order to bring some light into this phenomenon we present a mechanistic model to study the variably saturated hydraulic properties of bio-amended soils. Special emphasis is laid on the distribution of phases at pore-scale and the mechanisms to retain and let water flow through, providing valuable insights into phenomena behind bioclogging. Our approach consists in modeling the porous media as an ensemble of capillary tubes, obtained from the biofilm-free water retention curve. This methodology is extended by the incorporation of a biofilm composed of bacterial cells and extracellular polymeric substances (EPS). Moreover, such a microbial consortium displays a channeled geometry that shrinks/swells with suction. Analytical equations for the volumetric water content and the relative permeability can then be derived by assuming that biomass reshapes the pore space following specific geometrical patterns. The model is discussed by using data from laboratory studies and other approaches already existing in the literature. It can reproduce (i) displacements of the retention curve toward higher saturations and (ii) permeability reductions of distinct orders of magnitude. Our findings also illustrate how even very small amounts of biofilm may lead to significant changes in the hydraulic properties. We, therefore, state the importance of accounting for the hydraulic characteristics of biofilms and for a complex/more realistic geometry of colonies at the pore-scale

Can the vicious cycle of obscure or intractable gastrointestinal bleeding be broken in patients with atrial fibrillation subject to anticoagulant therapy? The role of percutaneous left atrial appendage closure

Gastrointestinal bleeding of obscure origin or with an intractable cause is particularly common in patients with atrial fibrillation subject to oral anticoagulant therapy. This condition is highly recurrent and therefore gives rise to high morbidity and mortality rates, thus entailing a vicious cycle that is difficult to solve.Percutaneous left atrial appendage closure has become a therapeutic alternative for patients with atrial fibrillation and a contraindication for oral anticoagulation. This technique would allow the discontinuation of oral anticoagulants, thus helping to reduce the risk for gastrointestinal bleeding, and would also be protective against embolic events in this group of patients, thereby eventually breaking this vicious cycle.We report our experience with percutaneous left atrial appendage closure in the management of patients with atrial fibrillation who are subject to oral anticoagulation therapy and suffer from obscure or intractable gastrointestinal bleeding