Implante percutáneo de la válvula autoexpandible CoreValve en pacientes con estenosis aórtica grave y aorta de porcelana: seguimiento a medio plazo

Introduction and objectives

There is little information on the use of transcatheter aortic valve implantation in patients with severe aortic stenosis and porcelain aorta. The primary aim of this study was to analyze death from any cause after CoreValve^® implantation in patients with severe aortic stenosis, with and without porcelain aorta.

Methods

In this multicenter, observational prospective study, carried out in 3 hospitals, percutaneous aortic valves were implanted in 449 patients with severely calcified aortic stenosis. Of these, 36 (8%) met the criteria for porcelain aorta. The primary end-point was death from any cause at 2 years.

Results

Patients with porcelain aorta more frequently had extracardiac vascular disease (11 [30.6%] vs 49 [11.9%]; P=.002), prior coronary revascularization (15 [41.7%] vs 98 [23.7%]; P=.017), and dyslipidemia (26 [72.2%] vs 186 [45%]; P=.02). In these patients, there was greater use of general anesthesia (15 [41.7%] vs 111 [16.9%]; P=.058) and axillary access (9 [25%] vs 34 [8.2%]; P=.004). The success rate of the procedure (94.4 vs 97.3%; P=.28) and the incidence of complications (7 [19.4%] vs 48 [11.6%]; P=.20) were similar in both groups. There were no statistically significant differences in the primary end point at 24 months of follow-up (8 [22.2%] vs 66 [16%]; P=.33). The only predictive variable for the primary end point was the presence of complications during implantation (hazard ratio=2.6; 95% confidence interval, 1.5-4.5; P=.001).

Conclusions

In patients with aortic stenosis and porcelain aorta unsuitable for surgery, percutaneous implantation of the CoreValve^® self-expanding valve prosthesis is safe and feasible.Full English text available from: www.revespcardiol.org/en     

Genome-wide methylation profiling in decitabine-treated patients with acute myeloid leukemia

The outcome of older (≥ 60 years) acute myeloid leukemia (AML) patients is poor, and novel treatments are needed. In a phase 2 trial for older AML patients, low-dose (20 mg/m(2) per day for 10 days) decitabine, a DNA hypomethylating azanucleoside, produced 47% complete response rate with an excellent toxicity profile. To assess the genome-wide activity of decitabine, we profiled pretreatment and post treatment (day 25/course 1) methylomes of marrow samples from patients (n = 16) participating in the trial using deep-sequencing analysis of methylated DNA captured by methyl-binding protein (MBD2). Decitabine significantly reduced global methylation compared with pretreatment baseline (P = .001). Percent marrow blasts did not correlate with global methylation levels, suggesting that hypomethylation was related to the activity of decitabine rather than to a mere decrease in leukemia burden. Hypomethylation occurred predominantly in CpG islands and CpG island-associated regions (P ranged from .03 to .04) A significant concentration (P < .001) of the hypomehtylated CpG islands was found in chromosome subtelomeric regions, suggesting a differential activity of decitabine in distinct chromosome regions. Hypermethylation occurred much less frequently than hypomethylation and was associated with low CpG content regions. Decitabine-related methylation changes were concordant with those previously reported in distinct genes. In summary, our study supports the feasibility of methylome analyses as a pharmacodynamic endpoint for hypomethylating therapies.     

Azadirachta indica Leaf Extract as Green Corrosion Inhibitor for Reinforced Concrete Structures: Corrosion Effectiveness against Commercial Corrosion Inhibitors and Concrete Integrity

The construction industry has extensively demanded novel green inhibition strategies for the conservation and protection of carbon steel-reinforced concrete structures. For the first time, the effect of Azadirachta indica leaf extract (Neem) as a potential corrosion inhibitor of carbon steel in reinforced concrete under corrosion in saline simulated media was evaluated. To assess the corrosion inhibition behavior of the Neem natural organic extract, three inorganic commercial inhibitors were tested to compare following the criteria established by Stratful for half-cell potential under a simulated chloride environment. Moreover, the effect of concrete integrity by the Neem treatment was recorded after different temperature conditions, slump, weight alteration, air content, compressive strength, and chloride-ions penetration. The results suggested that the Neem treatments did not alter the concrete integrity and the physicochemical parameters. We reached a promoted long-term corrosion protection of 95% after 182 days of evaluation. Thus far, our current results open up a new promising “green” road to the conservation of carbon steel in reinforced concrete for the construction industry.     

Developmental synaptic regulator,TWEAK/Fn14 signaling,is a determinant of synaptic function in models of stroke and neurodegeneration

Identifying molecular mediators of neural circuit development and/or function that contribute to circuit dysfunction when aberrantly reengaged in neurological disorders is of high importance. The role of the TWEAK/Fn14 pathway, which was recently reported to be a microglial/neuronal axis mediating synaptic refinement in experience-dependent visual development, has not been explored in synaptic function within the mature central nervous system. By combining electrophysiological and phosphoproteomic approaches, we show that TWEAK acutely dampens basal synaptic transmission and plasticity through neuronal Fn14 and impacts the phosphorylation state of pre- and postsynaptic proteins in adult mouse hippocampal slices. Importantly, this is relevant in two models featuring synaptic deficits. Blocking TWEAK/Fn14 signaling augments synaptic function in hippocampal slices from amyloid-beta–overexpressing mice. After stroke, genetic or pharmacological inhibition of TWEAK/Fn14 signaling augments basal synaptic transmission and normalizes plasticity. Our data support a glial/neuronal axis that critically modifies synaptic physiology and pathophysiology in different contexts in the mature brain and may be a therapeutic target for improving neurophysiological outcomes.

Neural circuit patterning, refinement, and plasticity are enabled by the dynamic strengthening, weakening, and pruning of chemical synapses in response to circuit activity. However, synapse loss and reduced plasticity are early hallmarks of chronic neurological disorders such as autism, schizophrenia and Alzheimer’s disease (AD) (1–3). It is therefore hypothesized that the underlying molecular mechanisms of pruning, although normally balanced in health, are dysregulated in disease. Particularly interesting is the notion that the mechanisms responsible for the reduction in functional synapses in disease reflect the aberrant reactivation of pathways important for synapse elimination in development. For example, in an AD model, synapse elimination was shown to be mediated by the complement pathway in the hippocampus (HC), reflecting aberrant reactivation of complement-dependent synapse elimination that occurs in the dorsal lateral geniculate nucleus (dLGN) of the thalamus during visual development (4). In such a paradigm, the reactivation of developmental mechanisms enables pathways that can act universally across different ages, circuits, and brain regions. Thus, the mechanisms underlying normal circuit development and their potential reactivation as key contributors to neurological diseases are areas of deep interest.In addition to chronic neurological disorders, circuitry changes also occur in acute ischemic stroke, the second leading cause of death worldwide and a cause of debilitating long-term disability. Interruptions in blood flow that deprive neurons of oxygen and nutrients result in significant cell death, followed by deficits in neurophysiological activity that are associated with poor motor recovery (5). Remarkably, the adult brain can undergo some degree of spontaneous poststroke recovery, apparently by engaging neuroplasticity mechanisms including remapping, synaptogenesis, and synaptic strengthening (5, 6). Despite these adaptations, over half of ischemic stroke patients fail to recover completely and continue to experience persistent long-term disability (7). The underlying signaling pathways that regulate synaptic physiology after stroke are an active topic of investigation.TNF-like weak inducer of apoptosis (TWEAK) protein, originally discovered as a cytokine produced by macrophages (8), signals through its injury-inducible transmembrane receptor, FGF-inducible molecule-14 (Fn14) (9). Consequently, the function of TWEAK/Fn14 signaling was elucidated as a driver of tissue remodeling in contexts of injury and disease in a variety of organ systems (10). Recently, findings have suggested a role for the TWEAK/Fn14 pathway in the central nervous system (CNS). Namely, several compelling observations indicate that TWEAK signaling through Fn14 might be a key molecular modulator of synaptic function in contexts of neurological challenge. TWEAK and Fn14 are up-regulated in the CNS in AD (11, 12, 13 and SI Appendix, Fig. S6A) and after ischemic stroke in humans and mice (14–16). Importantly, TWEAK/Fn14 signaling was also recently shown to be a pathway necessary for synapse maturation during experience-dependent visual development. Light-induced up-regulation of Fn14 in thalamocortical excitatory neurons and corresponding up-regulation of TWEAK in microglia mediate the elimination of weak synapses and strengthening of remaining synapses in the dLGN (17, 18). Indeed, the communication between neurons and supporting microglia has emerged as a key mechanism regulating neuronal circuitry, with microglia deploying their ramified processes to continuously survey and refine synapses in response to neural activity. Interestingly, TWEAK expression has also been shown to be microglia-enriched in the mouse cortex (19), suggesting that it may play a role in multiple brain regions. Thus, like the complement pathway, the TWEAK/Fn14 pathway could be an important regulator of synapse biology in visual development which is re-engaged and acts generally in different ages and brain regions to contribute to pathology.The involvement of TWEAK/Fn14 signaling in synapse physiology or pathophysiology outside of the developing visual system is unknown. We considered it to be a strong candidate modifier of synaptic function in adults given that Fn14 is up-regulated and required for synaptic refinement in experience-dependent visual development, and TWEAK and Fn14 are up-regulated in contexts of neurological injury/disease, suggesting that the TWEAK/Fn14 system is tuned to periods of substantial change in neuronal activity levels or environment (e.g., eye opening, ischemic stroke). We employed HC slices to test the hypothesis that the TWEAK/Fn14 pathway regulates synaptic function in adult mice and in different disease contexts and delineate its mechanism of action. Herein, we reveal that TWEAK, through neuronal Fn14, mediates acute dampening of basal synaptic transmission and synaptic plasticity in hippocampal slices from mature mice. Furthermore, we demonstrate that TWEAK/Fn14 signaling broadly impacts the phosphorylation state of critical synaptic proteins, suggesting a general role in synapse modulation. Finally, we show that pathway deficiency or pharmacological inhibition of TWEAK/Fn14 signaling augments synaptic transmission and plasticity in amyloid-beta (Aβ)–overexpressing mice and post ischemic stroke animals, two model systems featuring synaptic functional deficits. Thus, our results support that TWEAK/Fn14 constitutes a synaptic regulatory pathway with therapeutic potential for CNS disorders in the adult brain.     

The smoker's paradox in acute coronary syndrome: Is it real?

Introduction

Smoking is associated with atherosclerotic disease, but there is controversy about its protective nature after acute coronary syndrome (ACS).

A burst of auxilin recruitment determines the onset of clathrin-coated vesicle uncoating

Clathrin-coated pits assemble on a membrane and pinch off as coated vesicles. The released vesicles then rapidly lose their clathrin coats in a process mediated by the ATPase Hsc70, recruited by auxilin, a J-domain-containing cofactor. How is the uncoating process regulated? We find that during coat assembly small and variable amounts of auxilin are recruited transiently but that a much larger burst of association occurs after the peak of dynamin signal, during the transition between membrane constriction and vesicle budding. We show that the auxilin burst depends on domains of the protein likely to interact with lipid head groups. We conclude that the timing of auxilin recruitment determines the onset of uncoating. We propose that, when a diffusion barrier is established at the constricting neck of a fully formed coated pit and immediately after vesicle budding, accumulation of a specific lipid can recruit sufficient auxilin molecules to trigger uncoating.     

Usefulness of prostate-specific antigen (PSA) rise as a marker of prostate cancer in men treated with dutasteride: lessons from the REDUCE study

Study Type – Prognostic (RCT) Level of Evidence 1b What's known on the subject? and What does the study add? Previous studies used the decrease in PSA after 6 months of dutasteride treatment as a new ‘baseline’ PSA value from which subsequent rises may serve as a warning for prostate cancer; however, PSA tends to continue to decrease as dutasteride treatment continues. By comparing positive biopsy rates in the REDUCE study using any rise from nadir in the dutasteride arm and standard PSA decision criteria (NCCN) in the placebo arm, we demonstrated that the ability to detect prostate cancer and high grade prostate cancer is maintained with dutasteride treatment.

OBJECTIVES

? To determine if dutasteride‐treated men can be monitored safely and adequately for prostate cancer based on data from the Reduction by Dutasteride in Prostate Cancer Events (REDUCE) study. ? To analyse whether the use of treatment‐specific criteria for repeat biopsy maintains the usefulness of prostate‐specific antigen (PSA) level for detecting high grade cancers.

PATIENTS AND METHODS

? The REDUCE study was a randomized, double‐blind, placebo‐controlled investigation of whether dutasteride (0.5 mg/day) reduced the risk of biopsy‐detectable prostate cancer in men with a previous negative biopsy. ? The usefulness of PSA was evaluated using biopsy thresholds defined by National Comprehensive Cancer Network guidelines in the placebo group and any rise in PSA from nadir (the lowest PSA level achieved while in the study) in the dutasteride group. ? The number of cancers detected on biopsy in the absence of increased/suspicious PSA level as well as sensitivity, specificity, positive predictive value and negative predictive value for high grade prostate cancer detection were analysed by treatment group. ? Prostate cancer pathological characteristics were compared between men who did and did not meet biopsy thresholds.

RESULTS

? Of 8231 men randomized, 3305 (dutasteride) and 3424 (placebo) underwent at least one prostate biopsy during the study and were included in the analysis. ? If only men meeting biopsy thresholds underwent biopsy, 25% (47/191) of Gleason 7 and 24% (7/29) of Gleason 8–10 cancers would have been missed in the dutasteride group, and 37% (78/209) of Gleason 7 and 22% (4/18) Gleason 8–10 cancers would have been missed in the placebo group. ? In both groups, the incidence of Gleason 7 and Gleason 8–10 cancers generally increased with greater rises in PSA. ? Sensitivity of PSA kinetics was higher and specificity was lower for the detection of Gleason 7–10 cancers in men treated with dutasteride vs placebo. ? Men with Gleason 7 and Gleason 8–10 cancer meeting biopsy thresholds had greater numbers of positive cores, percent core involvement, and biopsy cancer volume vs men not meeting thresholds.

CONCLUSION

? Using treatment‐specific biopsy thresholds, the present study shows that the ability of PSA kinetics to detect high grade prostate cancer is maintained with dutasteride compared with placebo in men with a previous negative biopsy. ? The sensitivity of PSA kinetics with dutasteride was similar to (Gleason 8–10) or higher than (Gleason 7–10) the placebo group; however, biopsy decisions based on a single increased PSA measurement from nadir in the dutasteride group resulted in a lower specificity compared with using a comparable biopsy threshold in the placebo group, indicating the importance of confirmation of PSA measurements.