Association of left atrium voltage amplitude and distribution with the risk of atrial fibrillation recurrence and evolution after pulmonary vein isolation: An ultrahigh-density mapping study.

Introduction: Ultrahigh-density-voltage mapping (uHD M) is a new tool that can add new insights into the pathophysiology of atrial fibrillation (AF). The aim of this study was to evaluate the performance of uHD M in predicting postablation AF recurrence (AFR).

Methods And Results: We included 98 consecutive patients undergoing pulmonary vein isolation for AF (40.

Do 'difficult to identify' pulmonary vein connections explain continuing high recurrence rates after atrial fibrillation ablation?

Despite the emerging technical evolution of the last two decades, the primary success rate of single-procedure pulmonary vein isolation (PVI), the cornerstone for any atrial fibrillation ablation procedure, is highly variable ranging from 53% to 92%. The recent development of ultra-high-density electroanatomic mapping systems, capable of acquiring and annotating multiple electrograms, with high spatiotemporal precision, which are processed by automated algorithms to generate activation and substrate maps to support and guide ablation procedures, has opened a new stage in cardiac electrophysiology. In this article, we review the existing evidence on the utility of high-density mapping on catheter-based PVI, the possibility to detect pulmonary vein potentials that remain undetected when using a standard approach and its potential relevance to the clinical outcome, and how this new technology is providing novel pathophysiological insights on complete PVI and atrial fibrillation ablation outcomes.

Identification of pulmonary vein reconnection gaps with high-density mapping in redo atrial fibrillation ablation procedures.

Aims: Maps obtained by means of electroanatomic high-density mapping (HDM) systems have shown their use in the identification of conduction gaps in experimental atrial linear lesion models. The objective of this study was to assess the use of HDM in the recognition of reconnection gaps in pulmonary veins (PV) in redo atrial fibrillation (AF) ablation procedures.

Methods And Results: One hundred and eight patients were included in a non-randomized study that assessed the recognition of reconnection gaps in PV by means of HDM compared to a control group that received conventional non-fluoroscopic guidance with a circular multipolar catheter (CMC).

Atrial Fibrillation Ablation Guided by a Novel Nonfluoroscopic Navigation System.

Introduction And Objectives: Rhythmia is a new nonfluoroscopic navigation system that is able to create high-density electroanatomic maps. The aim of this study was to describe the acute outcomes of atrial fibrillation (AF) ablation guided by this system, to analyze the volume provided by its electroanatomic map, and to describe its ability to locate pulmonary vein (PV) reconnection gaps in redo procedures.

Methods: This observational study included 62 patients who underwent AF ablation with Rhythmia compared with a retrospective cohort who underwent AF ablation with a conventional nonfluoroscopic navigation system (Ensite Velocity).

Candida albicans survival, growth and biofilm formation are differently affected by mouthwashes: an in vitro study.

Candida albicans is the most common cause of oral mycoses. The aim of the present study was to investigate in vitro the susceptibility of C. albicans to mouthwashes, in terms of growth, survival and biofilm formation.

Mediguide-Assisted Transseptal Puncture without Echocardiographic Guidance.

Background: First description of a technique for left atrium transseptal puncture (TSP) with minimal radiation exposure by using the nonfluoroscopic MediGuide™ tracking system (MG; St. Jude Medical, St. Paul, MN, USA) without the assistance of intracardiac echocardiography.

Ablation of Atrial Fibrillation in Combination with Left Atrial Appendage Occlusion in A Single Procedure. Rationale and Technique.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and is associated with a fivefold increase in the risk of ischemic stroke and systemic embolism. Left atrial appendage (LAA) is the source of thrombi in up to 90% of patients with nonvalvular atrial fibrillation (AF). Although thromboembolic prophylaxis by means of oral anticoagulants (OAC) has been shown to be very effective (OAC), they also confer an inevitably risk of serious bleeding.

Inhibitory effects of different lactobacilli on Candida albicans hyphal formation and biofilm development.

The aim of this study was to investigate the effects of different species of Lactobacilli on hyphal formation and biofilm development by the opportunistic fungal pathogen Candida albicans. We employed 4 different Lactobacillus species, namely L. rhamnosus, L.

Impact of Candida albicans hyphal wall protein 1 (HWP1) genotype on biofilm production and fungal susceptibility to microglial cells.

The hyphal wall protein 1 (HWP1) gene of Candida albicans encodes for a fungal cell wall protein, required for hyphal development and yeast adhesion to epithelial cells; yet, its role in pathogenesis remains largely unknown. In the present study, we analyzed two C. albicans laboratory strains, the DAY286 (HWP1/HWP1) and the null mutant FJS24 (hwp1/hwp1) and six clinical isolates [3 harbouring the homozygous HWP1 gene (HWP1/HWP1) and 3 the heterologous gene (HWP1/hwp1)].

Human pathogenic viruses are retained in and released by Candida albicans biofilm in vitro.

Candida albicans is the most prevalent human fungal pathogen associated with biofilm formation on indwelling medical devices. Under this form, Candida represents an infectious reservoir difficult to eradicate and possibly responsible for systemic, often lethal infections. Currently, no information is available on the occurrence and persistence of pathogenic viruses within C.

Differential efficacy of endodontic obturation procedures: an ex vivo study.

By means of a double-chamber model, different root canal filling materials and procedures were compared. Briefly, the root canals of single-rooted human teeth, extracted for periodontal reasons, were instrumented and obturated by gutta-percha/Pulp Canal Sealer EWT (PCS) or by Resilon, in association with different sealers (Real Seal, RelyX Unicem or Meta). Obturation was achieved by traditional continuous wave of condensation technique (TCWCT), a modified version of it (MCWCT), or single cone technique (SCT).

Influence of hyaluronic acid on bacterial and fungal species, including clinically relevant opportunistic pathogens.

Hyaluronic acid (HA) has several clinical applications (aesthetic surgery, dermatology, orthopaedics and ophtalmology). Following recent evidence, suggesting antimicrobial and antiviral properties for HA, we investigated its effects on 15 ATCC strains, representative of clinically relevant bacterial and fungal species. The in vitro system employed allowed to assess optical density of broth cultures as a measure of microbial load in a time-dependent manner.

In vitro evaluation of antiviral and virucidal activity of a high molecular weight hyaluronic acid.

Background: hyaluronic acid (HA), a non-sulphated glycosaminoglycan, is present in synovial fluid, vitreous humour serum and many connective tissues. Pharmaceutical preparations of HA are used in clinical practice for wound healing, joint pain, kerato-conjunctivitis, asthma, mouth care, oesophageal-reflux, and gastritis. Moreover, it is used as a filler to counteract ageing and facial lipoatrophy.

Gene expression profiling of monocytes displaying herpes simplex virus 1 induced dysregulation of antifungal defences.

Recently, we showed that herpes simplex virus 1 (HSV-1)-infected monocytes have altered antifungal defences, in particular they show augmented phagocytosis of Candida albicans followed by a failure of the intracellular killing of the ingested fungi. On the basis of these functional data, comparative studies were carried out on the gene expression profile of cells infected with HSV-1 and/or C. albicans in order to investigate the molecular mechanisms underlying such virus-induced dysfunction.

An in vitro and ex vivo study on two antibiotic-based endodontic irrigants: a challenge to sodium hypochlorite.

Amongst the bacterial species which most often cause endodontic failures, Enterococcus faecalis is the most important. This study compared the effectiveness of sodium hypochlorite and two new generation antibiotic-based endodontic irrigants, Tetraclean and MTAD. By means of an in vitro agar dilution assay, we show that both Tetraclean and MTAD are 100% effective against 54 clinical isolates at dilutions up to 1:256 and 1:1048, respectively, whereas sodium hypochlorite completely loses its effectiveness when diluted more than 32 times.

The ABC transporter-encoding gene AFR1 affects the resistance of Cryptococcus neoformans to microglia-mediated antifungal activity by delaying phagosomal maturation.

The pathogenic yeast Cryptococcus neoformans has evolved several strategies to survive within phagocytes. Recently, it has been demonstrated that upregulation of the ATP binding cassette transporter-encoding gene antifungal resistance 1 (AFR1) is important not only for determining the resistance of C. neoformans to fluconazole but also in influencing fungal virulence.

Comparative in vitro and ex vivo studies on the bactericidal activity of Tetraclean, a new generation endodontic irrigant, and sodium hypochlorite.

The aim of this study was to compare the efficacy of a new generation endodontic irrigant, Tetraclean, to the widely used sodium hypochlorite. Tetraclean combines a powerful detergent effect with a strong antimicrobial efficacy, whereas sodium hypochlorite has several drawbacks and is sometimes ineffective in preventing microbial-mediated endodontic failure. The bactericidal activity of both irrigants against Enterococcus faecalis, the most commonly isolated species from root canals of teeth with post-treatment disease, was assessed i) in vitro, according to the European Standard lines for the evaluation of the bactericidal activity of chemical disinfectants, and ii) with an ex vivo model of extracted and decoronated human teeth, infected with E.

NF-kB activation and p38 phosphorilation in microglial cells infected with Leptospira or exposed to partially purified leptospiral lipoproteins.

Recently, we have shown a differential susceptibility of non-pathogenic vs. pathogenic leptospires to phagocytosis and killing by microglial cells. Although all ingested to some extent, only the pathogenic strains survived intracellularly while the non-pathogenic ones were killed in a time-dependent manner.

Adaptive response of microglial cells to in vitro infection by Candida albicans isolates with different genomic backgrounds.

It has been recently demonstrated that Candida albicans isolates with distinct genomic backgrounds (namely, b and c genotypes) express different susceptibility to antifungal activity by human monocytes in vitro. We show here that, although comparable in their ability to undergo dimorphic transition and in susceptibility to phagocytosis by microglial cells, the b and c isolates show striking differences in terms of intracellular survival. Only the c genotype resists indeed to intracellular killing and eventually replicates inside microglial cells, that in turn respond to fungal infection, preferentially towards the c genotype, with nuclear factor-kappaB (NF-kappaB) activation and increased Mip1alpha production.

The lack of Pneumococcal surface protein C (PspC) increases the susceptibility of Streptococcus pneumoniae to the killing by microglia.

Microglial cells, the resident phagocytes in the brain, share many phenotypical and functional characteristics with peripheral macrophages, suggesting that they may participate in an innate immune response against microorganisms invading the central nervous system (CNS). In this study, we demonstrate that the microglial cells constitutively exhibit antibacterial activity in vitro against Streptococcus pneumoniae. By using a Pneumococcal surface protein C (PspC)-deleted strain and its wild-type counterpart, we found that the extent of such an activity is significantly influenced by the presence of a PspC molecule on the bacterial surface.

Biological importance of the two Toll-like receptors, TLR2 and TLR4, in macrophage response to infection with Candida albicans.

The aim of this study was to assess the role of TLR2, TLR4 and MyD88 accessory molecule in the effector and secretory response of macrophages to viable microbial agents. Using TLR-deleted macrophage cell lines generated from the bone marrow of genetically engineered mice (TLR4 gene-deficient, MyD88- and TLR2-knockout mice) and wild-type control mice, we found that TLR2-deleted macrophages exhibit increased ability to contain Candida albicans infection compared to TLR2+/+ counterpart. In contrast, both MyD88-/- and TLR4-/- macrophages retain levels of functional activity comparable to that of the respective wild-type MyD88+/+ and TLR4+/+ controls.

The human immunodeficiency virus (HIV) protease inhibitor indinavir directly affects the opportunistic fungal pathogen Cryptococcus neoformans.

Highly active antiretroviral therapy (HAART), that includes human immunodeficiency virus (HIV) protease inhibitors (PIs), has been remarkably efficacious including against some opportunistic infections. In this report we investigated the effect(s) of the PI indinavir on protease activity by Cryptococcus neoformans, an opportunistic fungal pathogen responsible for recurrent meningoencephalitis in AIDS patients. Indinavir was also tested for potential effects on other parameters, such as fungal viability, growth ability and susceptibility to immune effector cells.

Legionella infection risk from domestic hot water.

We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp.

Relationship between mineral content of domestic hot water and microbial contamination.

The relationship between Legionella and Pseudomonas spp contamination and mineral content of domestic hot waters was investigated in a cross-sectional Italian survey. Pseudomonas spp contamination was associated with elevated Ca, but lower Fe and free chlorine content in the water. Waters with Cu concentrations > 50 microg/L prevented Legionella spp colonisation (OR = 0.