Usefulness of risk scores and predictors of atrial fibrillation recurrence after elective electrical cardioversion.

INTRODUCTION: Electrical cardioversion (ECV) is a frequently used procedure for restoring sinus rhythm in atrial fibrillation (AF); however, the rate of recurrence is high. The identification of patients at high risk of recurrence could influence the decision-making process. The present study evaluates the predictive value of risk scores in atrial fibrillation recurrence after elective electrical cardioversion. METHODS: Unicentric, observational, and prospective study of adult patients who have undergone an elective ECV as rhythm control strategy between July 2017 and September 2022. RESULTS: From the 283 analyzed patients (mean age 63.95 ± 10.76212, 74.9% male); 99 had paroxysmal AF (35%) and 159 (59%) presented AF recurrence during a follow-up of 6 months. In patients with post-ECV AF recurrence, the period of time from diagnosis until the performance of the procedure was longer (393 ± 891 vs. 195 ± 527, p = .02). No paroxysmal AF (71.3% vs. 57.8%, p = .02) and LA dilatation with >40 mL/m2 (35.9% vs. 23.3%, p = .02) volumes were more frequent within these patients. AF recurrence was more frequent in patients who had previous ECV (HR = 1.32; 95% CI: 1.12-2.35; p = .01) and more than 1 shock to recover sinus rhythm (HR = 1.62; 95% CI: 1.07-1.63; p = .01). The SLAC, ALARMEc, ATLAS, and CAAP-AF scores were statistically significant, although with a moderate predictive capacity for post-ECV recurrence. CONCLUSIONS: Risk scores analyzed showed a modest value predicting AF recurrence after ECV. Previous ECV, and greater difficulty in restoring SR were independent predictors of recurrence.

An SDN-Based Solution for Horizontal Auto-Scaling and Load Balancing of Transparent VNF Clusters.

This paper studies the problem of the dynamic scaling and load balancing of transparent virtualized network functions (VNFs). It analyzes different particularities of this problem, such as loop avoidance when performing scaling-out actions, and bidirectional flow affinity. To address this problem, a software-defined networking (SDN)-based solution is implemented consisting of two SDN controllers and two OpenFlow switches (OFSs). In this approach, the SDN controllers run the solution logic (i.e., monitoring, scaling, and load-balancing modules). According to the SDN controllers instructions, the OFSs are responsible for redirecting traffic to and from the VNF clusters (i.e., load-balancing strategy). Several experiments were conducted to validate the feasibility of this proposed solution on a real testbed. Through connectivity tests, not only could end-to-end (E2E) traffic be successfully achieved through the VNF cluster, but the bidirectional flow affinity strategy was also found to perform well because it could simultaneously create flow rules in both switches. Moreover, the selected CPU-based load-balancing method guaranteed an average imbalance below 10% while ensuring that new incoming traffic was redirected to the least loaded instance without requiring packet modification. Additionally, the designed monitoring function was able to detect failures in the set of active members in near real-time and active new instances in less than a minute. Likewise, the proposed auto-scaling module had a quick response to traffic changes. Our solution showed that the use of SDN controllers along with OFS provides great flexibility to implement different load-balancing, scaling, and monitoring strategies.

An Energy-Friendly Scheduler for Edge Computing Systems.

The deployment of modern applications, like massive Internet of Things (IoT), poses a combination of challenges that service providers need to overcome: high availability of the offered services, low latency, and low energy consumption. To overcome these challenges, service providers have been placing computing infrastructure close to the end users, at the edge of the network. In this vein, single board computer (SBC) clusters have gained attention due to their low cost, low energy consumption, and easy programmability. A subset of IoT applications requires the deployment of battery-powered SBCs, or clusters thereof. More recently, the deployment of services on SBC clusters has been automated through the use of containers. The management of these containers is performed by orchestration platforms, like Kubernetes. However, orchestration platforms do not consider remaining energy levels for their placement decisions and therefore are not optimized for energy-constrained environments. In this study, we propose a scheduler that is optimised for energy-constrained SBC clusters and operates within Kubernetes. Through comparison with the available schedulers we achieved 23% fewer event rejections, 83% less deadline violations, and approximately a 59% reduction of the consumed energy throughout the cluster.

Minimally invasive system to reliably characterize ventricular electrophysiology from living donors.

Cardiac tissue slices preserve the heterogeneous structure and multicellularity of the myocardium and allow its functional characterization. However, access to human ventricular samples is scarce. We aim to demonstrate that slices from small transmural core biopsies collected from living donors during routine cardiac surgery preserve structural and functional properties of larger myocardial specimens, allowing accurate electrophysiological characterization. In pigs, we compared left ventricular transmural core biopsies with transmural tissue blocks from the same ventricular region. In humans, we analyzed transmural biopsies and papillary muscles from living donors. All tissues were vibratome-sliced. By histological analysis of the transmural biopsies, we showed that tissue architecture and cellular organization were preserved. Enzymatic and vital staining methods verified viability. Optically mapped transmembrane potentials confirmed that action potential duration and morphology were similar in pig biopsies and tissue blocks. Action potential morphology and duration in human biopsies and papillary muscles agreed with published ranges. In both pigs and humans, responses to increasing pacing frequencies and ß-adrenergic stimulation were similar in transmural biopsies and larger tissues. We show that it is possible to successfully collect and characterize tissue slices from human myocardial biopsies routinely extracted from living donors, whose behavior mimics that of larger myocardial preparations both structurally and electrophysiologically.

Implant of mesenchymal cells decreases acute cellular rejection in small bowel transplantation.

OBJECTIVE: The objective of the study was to show adipose tissue-derived mesenchymal stem cells (AD-MSCs) immunomodulatory effects in small bowel transplantation (SBTx). MATERIALS AND METHODS: Forty Wistar Han rats (age: 10-12 weeks): were allogenic receptor rats and were allotted in 2 groups. Control group: rats undergoing orthopic SBTx ; AD-MSCs group: rats undergoing orthotopic SBTx plus AD-MSCs. Male Lewis rats were allogeneic small bowel donors. Rejection was confirmed by histological study of the explanted intestine, enterocyte apoptosis was determined in crypts and the lamina propria of the small bowel. Cytokine concentration levels (enzyme-linked immunosorbent assay) (interleukin [IL]-4, IL-10, IL-12, IL-17, IL-21, IL-23, tumor necrosis factor-alpha, and transforming growth factor [TGF]-b1) and cell percentages (flow cytometry) (CD3+ CD4+, CD8+, CD4+/25+, CD8+/25+, CD4+/25+/Foxp3+, and CD8+/25+/Foxp3+) were assessed in peripheral blood preoperatively and after death. RESULTS: Treatment with AD-MSCs produced a significantly lower risk of rejection in the first 7 post-operative days (five rejection cases among 20 rats in the control group and only one case in the AD-MSCs group). Treg cells and TGFb1 levels showed a significant increase in the AD-MSCs group. CONCLUSIONS: The local implantation of AD-MSC in the anastomosis and the intestinal lumen can induce a regulatory immune response, by increasing the percentages of Treg cells and TGb-1 levels, leading to a lower risk of acute rejection by cell mediation, in the first 7 days of the intestinal transplant. We think that the implantation of AD-MSCs, in the anastomoses and in the lumen of the donor intestine, could give rise to a chimera of donor-recipient cells.

OBJETIVO: Mostrar el efecto inmunomodulador de las células madre mesenquimales (AD-MSCs) en el trasplante de intestino delgado (SBTx). MÉTODO: 40 ratas Wistar Han (edad: 10-12 semanas): grupo control (SBTx) y grupo AD-MSCs (SBTx + AD-MSCs implantadas en las anastomosis distal y proximal del intestino delgado y en la luz intestinal). El intestino delgado provino de ratas Lewis. El rechazo se confirmó histológicamente. Se estudió la apoptosis de los enterocitos en las criptas y en la lámina propia del intestino delgado. Se determinaron por ELISA las citocinas (IL-4, IL-10, IL-12, IL-17, IL-21, IL-23, TNF-α, TGF-b1) en sangre periférica y por citometría de flujo los porcentajes celulares (CD3+ CD4+, CD8+, CD4+/25+, CD8+/25+, CD4+/25+/Foxp3+, CD8+/25+/Foxp3+) en el preoperatorio y después de la muerte. RESULTADOS: El empleo de AD-MSCs se asoció a una disminución significativa del riesgo de rechazo en los primeros 7 días posoperatorios (cinco casos de rechazo de 20 ratas en el grupo control y un solo caso en el grupo AD-MSCs). Las células Treg y los valores de TGFb1 mostraron un incremento significativo en el grupo AD-MSCs. CONCLUSIONES: El implante local de AD-MSCs en las anastomosis del trasplante de intestino delgado podría disminuir el rechazo celular agudo. Pensamos que la implantación de AD-MSCs, en las anastomosis y en el lumen del intestino donante, podría dar lugar a un quimera de células donante-receptor.

A Framework for the Joint Placement of Edge Service Infrastructure and User Plane Functions for 5G.

Achieving less than 1 ms end-to-end communication latency, required for certain 5G services and use cases, is imposing severe technical challenges for the deployment of next-generation networks. To achieve such an ambitious goal, the service infrastructure and User Plane Function (UPF) placement at the network edge, is mandatory. However, this solution implies a substantial increase in deployment and operational costs. To cost-effectively solve this joint placement problem, this paper introduces a framework to jointly address the placement of edge nodes (ENs) and UPFs. Our framework proposal relies on Integer Linear Programming (ILP) and heuristic solutions. The main objective is to determine the ENs and UPFs' optimal number and locations to minimize overall costs while satisfying the service requirements. To this aim, several parameters and factors are considered, such as capacity, latency, costs and site restrictions. The proposed solutions are evaluated based on different metrics and the obtained results showcase over 20 % cost savings for the service infrastructure deployment. Moreover, the gap between the UPF placement heuristic and the optimal solution is equal to only one UPF in the worst cases, and a computation time reduction of over 35 % is achieved in all the use cases studied.

Proteomics Analysis of Extracellular Matrix Remodeling During Zebrafish Heart Regeneration.

Adult zebrafish, in contrast to mammals, are able to regenerate their hearts in response to injury or experimental amputation. Our understanding of the cellular and molecular bases that underlie this process, although fragmentary, has increased significantly over the last years. However, the role of the extracellular matrix (ECM) during zebrafish heart regeneration has been comparatively rarely explored. Here, we set out to characterize the ECM protein composition in adult zebrafish hearts, and whether it changed during the regenerative response. For this purpose, we first established a decellularization protocol of adult zebrafish ventricles that significantly enriched the yield of ECM proteins. We then performed proteomic analyses of decellularized control hearts and at different times of regeneration. Our results show a dynamic change in ECM protein composition, most evident at the earliest (7 days postamputation) time point analyzed. Regeneration associated with sharp increases in specific ECM proteins, and with an overall decrease in collagens and cytoskeletal proteins. We finally tested by atomic force microscopy that the changes in ECM composition translated to decreased ECM stiffness. Our cumulative results identify changes in the protein composition and mechanical properties of the zebrafish heart ECM during regeneration.

The role of extracellular matrix on liver stem cell fate: A dynamic relationship in health and disease.

The liver stem cell niche is a specialized and dynamic microenvironment with biomechanical and biochemical characteristics that regulate stem cell behavior. This is feasible due to the coordination of a complex network of secreted factors, small molecules, neural, blood inputs and extracellular matrix (ECM) components involved in the regulation of stem cell fate (self-renewal, survival, and differentiation into more mature phenotypes like hepatocytes and cholangiocytes). In this review, we describe and summarize all the major components that play essential roles in the liver stem cell niche, in particular, growth factor signaling and the biomechanical properties of the ECM.

Fate predetermination of cardiac myocytes during zebrafish heart regeneration.

Adult zebrafish have the remarkable ability to regenerate their heart upon injury, a process that involves limited dedifferentiation and proliferation of spared cardiomyocytes (CMs), and migration of their progeny. During regeneration, proliferating CMs are detected throughout the myocardium, including areas distant to the injury site, but whether all of them are able to contribute to the regenerated tissue remains unknown. Here, we developed a CM-specific, photoinducible genetic labelling system, and show that CMs labelled in embryonic hearts survive and contribute to all three (primordial, trabecular and cortical) layers of the adult zebrafish heart. Next, using this system to investigate the fate of CMs from different parts of the myocardium during regeneration, we show that only CMs immediately adjacent to the injury site contributed to the regenerated tissue. Finally, our results show an extensive predetermination of CM fate during adult heart regeneration, with cells from each myocardial layer giving rise to cells that retain their layer identity in the regenerated myocardium. Overall, our results indicate that adult heart regeneration in the zebrafish is a rather static process governed by short-range signals, in contrast to the highly dynamic plasticity of CM fates that takes place during embryonic heart regeneration.

Time Shared Optical Network (TSON): a novel metro architecture for flexible multi-granular services.

This paper presents the Time Shared Optical Network (TSON) as metro mesh network architecture for guaranteed, statistically-multiplexed services. TSON proposes a flexible and tunable time-wavelength assignment along with one-way tree-based reservation and node architecture. It delivers guaranteed sub-wavelength and multi-granular network services without wavelength conversion, time-slice interchange and optical buffering. Simulation results demonstrate high network utilization, fast service delivery, and low end-to-end delay on a contention-free sub-wavelength optical transport network. In addition, implementation complexity in terms of Layer 2 aggregation, grooming and optical switching has been evaluated.

Effect of age on cytokine response in an experimental model of osteomyelitis.

To study the effect of age on cytokine response in an experimental model of osteomyelitis. Forty adult male Wistar rats received a stainless steel needle, intramedullarly in the left tibia. Young rats (3 months old) and old rats (22 months old) were allotted in: Group A: Sterile implant. Group B: Sterile implant + slime producing S. aureus. Rats were sacrificed 9 weeks after surgery. Determinations: Cytokines (ELISA) in blood and in tibia extract and the number of bacteria in tibia and implant. The Wilcoxon, Mann-Whitney U tests were used (P < or = 0.01 significant). Infection was detected in every old rat receiving S. aureus, and in 7 of 10 young rats. In blood: prior to surgery, old rats presented higher IL-2 and lower IL-4 levels. Surgery alone did not induce significant changes in old rats; surgery + S. aureus induced significant increases of IL-2 and IL-10 in young rats, and of IL-6 in old rats. Tibia analysis S. aureus group showed increased levels of: IL-10 in young rats, and IL-1beta in old rats. In experimentally induced osteomyelitis, significant differences were observed in cytokine response with regard to age.

Immune cell variations in patients with hip fracture.

Hip fracture is an increasing pathology in the patients with increasing age. Immunological response differences may appear between different age groups. The purpose of this study was to investigate the immune response in patients with subcapital hip fracture and the relationship with age. Prospective study of 100 patients with displaced subcapital femoral fracture between 2000 and 2004, divided into three age groups: over 90 years (13), 80-90 (56) and under 80 years (27). The chi(2)-test, analysis of variance and Student's t-test were applied. Correlation coefficient and the Spearman test were used to study linear correlation. The T helper cells decreased with age, this inverse correlation was significant. There was a direct correlation between CD16% and age. IgA, IgG and IgM levels did not show any significant relationship with age in our study. Nevertheless, the IgE levels in peripheral blood showed a significant direct correlation with age. Basophils percentage presented an inverse correlation with age. Age is associated to some immune changes in patients suffering hip fracture.