ß1-adrenoceptor expression on GABAergic interneurons in primate dorsolateral prefrontal cortex: potential role in stress-induced cognitive dysfunction.

Uncontrollable stress exposure impairs working memory and reduces the firing of dorsolateral prefrontal cortex (dlPFC) "Delay cells", involving high levels of norepinephrine and dopamine release. Previous work has focused on catecholamine actions on dlPFC pyramidal cells, but inhibitory interneurons may contribute as well. The current study combined immunohistochemistry and multi-scale microscopy with iontophoretic physiology and behavioral analyses to examine the effects of beta1-noradrenergic receptors (ß1-ARs) on inhibitory neurons in layer III dlPFC. We found ß1-AR robustly expressed on different classes of inhibitory neurons labeled by the calcium-binding proteins calbindin (CB), calretinin (CR), and parvalbumin (PV). Immunoelectron microscopy confirmed ß1-AR expression on the plasma membrane of PV-expressing dendrites. PV interneurons can be identified as fast-spiking (FS) in physiological recordings, and thus were studied in macaques performing a working memory task. Iontophoresis of a ß1-AR agonist had a mixed effect, increasing the firing of a subset and decreasing the firing of others, likely reflecting loss of firing of the entire microcircuit. This loss of overall firing likely contributes to impaired working memory during stress, as pretreatment with the selective ß1-AR antagonist, nebivolol, prevented stress-induced working memory deficits. Thus, selective ß1-AR antagonists may be helpful in treating stress-related disorders.

[Evolutionary analysis of patient´s morbidity and mortality in emergency surgical care during the pandemic: retrospective comparison between the first and second waves of COVID-19.] / Análisis evolutivo de morbimortalidad en cirugía de urgencias durante la pandemia: comparación retrospectiva entre primera y segunda ola de COVID-19.

INTRODUCTION: Since the beginning of the pandemic, morbidity and mortality in emergency care of surgical patients have been the subject of several studies. However, most of these have compared this variable with that of the pre-COVID period, ignoring its evolution during the pandemic itself. In order to analyze this possible change, we performed a comparative study of morbidity and mortality in emergency surgery between the first and second waves of the pandemic in our center. MATERIAL AND METHODS: Retrospective longitudinal study including all patients over the age of 18 admitted and/or operated in the emergency setting in the two maximum incidence periods (MIP) of COVID-19 infection (1st MIP: 22/03/2020-31/05/2020; 2nd MIP: 26/08/2020-30/11/2020). The incidence of SARS-CoV-2 infection, treatment received, early morbidity and mortality and possible risk factors for complications were analyzed. RESULTS: A total of 173 patients were analyzed (1st MIP: 66; 2nd MIP: 107). The incidence of COVID-19 was higher in the second period (14.95% vs. 4.54%). SARS-CoV-2 infection was associated with a higher rate of complications, however, no statistically significant differences were observed in morbimortality rate, either in the total sample (p=0.746) or in patients with a positive COVID-19 test (p=0.582) between both periods. Surgical treatment was found to be associated with a lower complication rate in both the first (p=0.006) and second wave (p=0.014), and it was more frequent in the second PMI (70.1 vs. 57.6%) although statistical significance was not reached (p= 0.065). CONCLUSIONS: No significant differences were observed in morbimortality of patients admitted and/or operated in the emergency setting in the two periods of maximum incidence of SARS-CoV-2 in our center. Surgical treatment was associated with a lower morbimortality rate, and it was more frequent in the second MIP.

Application of the diagnostic criteria for Common Variable Immunodeficiency in resource-limited settings

Introduction: Common variable immunodeficiency (CVID) is the most prevalent symptom-atic humoral deficiency; however, its heterogeneous presentation makes the diagnosis diffi-cult. The present study is aimed to verify the CVID diagnostic criteria as established by the European Society for Immunodeficiencies in 42 CVID patients from our outpatient clinic. Methods: Information was collected from their medical records and when needed, lymphocyte subpopulations in peripheral blood (PB) were performed by flow cytometry. Results: All the patients fulfilled the clinical working definition for CVID and showed decreased serum IgG and IgA at diagnosis. Over two-thirds of the patients had decreased memory B cell percentages. However, the remaining patients exhibited other quantitative B cell defects in PB. Evaluation of vaccination responses was only found in 13 records and 69% were not respon-sive. None of the patients were subjected to vaccination studies to both, T-cell dependent and independent antigens. The two required tests to evaluate T cell responses were performed in 84.2% of the patients and reported normal. Without the support of third-party payers, only 34.2% of our patients would have completed the required evaluations. Conclusions: Further efforts are needed to speed up CVID diagnosis in low-resourced settings, increasing the availability of the required resources and optimizing the healthcare supply chain (AU)

Valorisation of cellulosic rejections from wastewater treatment plants through sugar production.

The widespread use of wipes and other sanitary products made of nonwoven fibres has led to an enormous problem in wastewater treatment systems that has been underestimated for some time. To date, there are no practical alternatives for recycling and valorisation. In this study, cellulosic rejections recovered from a wastewater treatment plant in Barcelona (Spain) were characterised and treated using hydrothermal and enzymatic methods to obtain free sugars. Steam explosion and autoclave pre-treatments were performed at different temperatures (120, 130, or 150 °C) and residence times (10-40 min) under neutral, acidic or basic conditions. The solids obtained after the pre-treatment, as well as the untreated material, were subjected to enzymatic hydrolysis using commercial enzymes. The untreated substrate reached the highest sugar production: 29 g glucose and xylose per 100 g of the cellulosic rejections, equivalent to 86% of the sugars contained in the initial material. These sugars can subsequently be transformed into biofuels or bioproducts within a biorefinery approach.

Effect of RecA inactivation and detoxification systems on the evolution of ciprofloxacin resistance in Escherichia coli.

BACKGROUND: Suppression of SOS response and overproduction of reactive oxygen species (ROS) through detoxification system suppression enhance the activity of fluoroquinolones. OBJECTIVES: To evaluate the role of both systems in the evolution of resistance to ciprofloxacin in an isogenic model of Escherichia coli. METHODS: Single-gene deletion mutants of E. coli BW25113 (wild-type) (ΔrecA, ΔkatG, ΔkatE, ΔsodA, ΔsodB), double-gene (ΔrecA-ΔkatG, ΔrecA-ΔkatE, ΔrecA-ΔsodA, ΔrecA-ΔsodB, ΔkatG-ΔkatE, ΔsodB-ΔsodA) and triple-gene (ΔrecA-ΔkatG-ΔkatE) mutants were included. The response to sudden high ciprofloxacin pressure was evaluated by mutant prevention concentration (MPC). The gradual antimicrobial pressure response was evaluated through experimental evolution and antibiotic resistance assays. RESULTS: For E. coli BW25113 strain, ΔkatE, ΔsodB and ΔsodB/ΔsodA mutants, MPC values were 0.25 mg/L. The ΔkatG, ΔsodA, ΔkatG/katE and ΔrecA mutants showed 2-fold reductions (0.125 mg/L). The ΔkatG/ΔrecA, ΔkatE/ΔrecA, ΔsodA/ΔrecA, ΔsodB/ΔrecA and ΔkatG/ΔkatE/ΔrecA strains showed 4-8-fold reductions (0.03-0.06 mg/L) relative to the wild-type. Gradual antimicrobial pressure increased growth capacity for ΔsodA and ΔsodB and ΔsodB/ΔsodA mutants (no growth in 4 mg/L) compared with the wild-type (no growth in the range of 0.5-2 mg/L). Accordingly, increased growth was observed with the mutants ΔrecA/ΔkatG (no growth in 2 mg/L), ΔrecA/ΔkatE (no growth in 2 mg/L), ΔrecA/ΔsodA (no growth in 0.06 mg/L), ΔrecA/ΔsodB (no growth in 0.25 mg/L) and ΔrecA/ΔkatG/ΔkatE (no growth in 0.5 mg/L) compared with ΔrecA (no growth in the range of 0.002-0.015 mg/L). CONCLUSIONS: After RecA inactivation, gradual exposure to ciprofloxacin reduces the evolution of resistance. After suppression of RecA and detoxification systems, sudden high exposure to ciprofloxacin reduces the evolution of resistance in E. coli.

Mixture effects of a fungicide and an antibiotic: Assessment and prediction using a decomposer-detritivore system.

Antimicrobials, such as fungicides and antibiotics, pose a risk for microbial decomposers (i.e., bacteria and aquatic fungi) and invertebrate detritivores (i.e., shredders) that play a pivotal role in the ecosystem function of leaf litter breakdown. Although waterborne toxicity and diet-related effects (i.e., dietary exposure and microorganism-mediated alterations in food quality for shredders) of fungicides and antibiotics on decomposer-detritivore systems have been increasingly documented, their joint effect is unknown. We therefore assessed waterborne and dietary effects of an antimicrobial mixture consisting of the fungicide azoxystrobin (AZO) and the antibiotic ciprofloxacin (CIP) on microbial decomposers and the shredder Gammarus fossarum using a tiered approach. We compared effect sizes measured in the present study with model predictions (i.e., independent action) based on published data. During a 7-day feeding activity assay quantifying waterborne toxicity in G. fossarum, the leaf consumption of gammarids was reduced by ∼60 % compared to the control when subjected to the mixture at concentrations of each component causing a 20 % reduction in the same response variable when applied individually. Moreover, the selective feeding of gammarids during the food choice assay indicated alterations in food quality induced by the antimicrobial mixture. The food selection and, in addition, the decrease in microbial leaf decomposition is likely linked to changes in leaf-associated bacteria and fungi. During a long-term assay, energy processing, growth and energy reserves of gammarids were increased in presence of 15 and 500 µg/L of AZO and CIP, respectively, through the dietary pathway. These physiological responses were probably driven by CIP-induced alterations in the gut microbiome or immune system of gammarids. In general, model predictions matched observed effects caused by waterborne exposure on the leaf consumption, energy processing and growth of gammarids during short- and long-term assays, respectively. However, when complex horizontal (bacteria and aquatic fungi) and vertical (leaf-associated microorganisms and shredders) interactions were involved, model predictions partly over- or underestimated mixture effects. Therefore, the present study identifies uncertainties of mixture effect predictions for complex biological systems calling for studies targeting the underlying processes and mechanisms.

Synergistic Quinolone Sensitization by Targeting the recA SOS Response Gene and Oxidative Stress.

Suppression of the recA SOS response gene and reactive oxygen species (ROS) overproduction have been shown, separately, to enhance fluoroquinolone activity and lethality. Their putative synergistic impact as a strategy to potentiate the efficacy of bactericidal antimicrobial agents such as fluoroquinolones is unknown. We generated Escherichia coli mutants that exhibited a suppressed ΔrecA gene in combination with inactivated ROS detoxification system genes (ΔsodA, ΔsodB, ΔkatG, ΔkatE, and ΔahpC) or inactivated oxidative stress regulator genes (ΔoxyR and ΔrpoS) to evaluate the interplay of both DNA repair and detoxification systems in drug response. Synergistic sensitization effects, ranging from 7.5- to 30-fold relative to the wild type, were observed with ciprofloxacin in double knockouts of recA and inactivated detoxification system genes. Compared to recA knockout, inactivation of an additional detoxification system gene reduced MIC values up to 8-fold. In growth curves, no growth was evident in mutants doubly deficient for recA gene and oxidative detoxification systems at subinhibitory concentrations of ciprofloxacin, in contrast to the recA-deficient strain. There was a marked reduction of viable bacteria in a short period of time when the recA gene and other detoxification system genes (katG, sodA, or ahpC) were inactivated (using absolute ciprofloxacin concentrations). At 4 h, a bactericidal effect of ciprofloxacin was observed for ΔkatG ΔrecA and ΔahpC ΔrecA double mutants compared to the single ΔrecA mutant (Δ3.4 log10 CFU/ml). Synergistic quinolone sensitization, by targeting the recA gene and oxidative detoxification stress systems, reinforces the role of both DNA repair systems and ROS in antibiotic-induced bacterial cell death, opening up a new pathway for antimicrobial sensitization.

Effect of RecA inactivation on quinolone susceptibility and the evolution of resistance in clinical isolates of Escherichia coli.

BACKGROUND: SOS response suppression (by RecA inactivation) has been postulated as a therapeutic strategy for potentiating antimicrobials against Enterobacterales. OBJECTIVES: To evaluate the impact of RecA inactivation on the reversion and evolution of quinolone resistance using a collection of Escherichia coli clinical isolates. METHODS: Twenty-three E. coli clinical isolates, including isolates belonging to the high-risk clone ST131, were included. SOS response was suppressed by recA inactivation. Susceptibility to fluoroquinolones was determined by broth microdilution, growth curves and killing curves. Evolution of quinolone resistance was evaluated by mutant frequency and mutant prevention concentration (MPC). RESULTS: RecA inactivation resulted in 2-16-fold reductions in fluoroquinolone MICs and modified EUCAST clinical category for several isolates, including ST131 clone isolates. Growth curves and time-kill curves showed a clear disadvantage (up to 10 log10 cfu/mL after 24 h) for survival in strains with an inactivated SOS system. For recA-deficient mutants, MPC values decreased 4-8-fold, with values below the maximum serum concentration of ciprofloxacin. RecA inactivation led to a decrease in mutant frequency (≥103-fold) compared with isolates with unmodified SOS responses at ciprofloxacin concentrations of 4×MIC and 1 mg/L. These effects were also observed in ST131 clone isolates. CONCLUSIONS: While RecA inactivation does not reverse existing resistance, it is a promising strategy for increasing the effectiveness of fluoroquinolones against susceptible clinical isolates, including high-risk clone isolates.

COVID-19 mortality in an area of northeast Brazil: epidemiological characteristics and prospective spatiotemporal modelling.

This study aimed to analyse the spatial-temporal distribution of COVID-19 mortality in Sergipe, Northeast, Brazil. It was an ecological study utilising spatiotemporal analysis techniques that included all deaths confirmed by COVID-19 in Sergipe, from 2 April to 14 June 2020. Mortality rates were calculated per 100 000 inhabitants and the temporal trends were analysed using a segmented log-linear model. For spatial analysis, the Kernel estimator was used and the crude mortality rates were smoothed by the empirical Bayesian method. The space-time prospective scan statistics applied the Poisson's probability distribution model. There were 391 COVID-19 registered deaths, with the majority among ⩾60 years old (62%) and males (53%). The most prevalent comorbidities were hypertension (40%), diabetes (31%) and cardiovascular disease (15%). An increasing mortality trend across the state was observed, with a higher increase in the countryside. An active spatiotemporal cluster of mortality comprising the metropolitan area and neighbouring cities was identified. The trend of COVID-19 mortality in Sergipe was increasing and the spatial distribution of deaths was heterogeneous with progression towards the countryside. Therefore, the use of spatial analysis techniques may contribute to surveillance and control of COVID-19 pandemic.

Breast-milk derived potential probiotics as strategy for the management of childhood obesity.

Obesity and overweight, and their concomitant metabolic diseases, emerge as one of the most severe health problems in the world. Prevention and management of obesity are proposed to begin early in childhood, when probiotics may have a role. The Simulator of the Human Intestinal Microbial Ecosystem (SHIME®), in a dynamic validated in vitro system able to simulate the different parts of the gastrointestinal tract, has proven to be useful in analyzing the human intestinal microbial community. L. plantarum 73a and B. animalis subsp. lactis INL1, two strains isolated from breast milk, were assayed in the SHIME® using the fecal microbiota of an obese child. L. plantarum 73a alone or in combination with B. animalis subsp. lactis INL1 demonstrated survival capacity in the SHIME® system. The administration of both strains increased the alpha diversity of the microbiota and reduced the levels of the phylum Proteobacteria. In particular, the genera Escherichia, Shigella, and Clostridium_sensu_stricto_1 were significantly reduced when both strains were administered. The increase of Proteobacteria phylum is generally associated with the microbiota of obese people. Escherichia and Shigellacan be involved in inflammation-dependent adiposity and insulin resistance. L. plantarum73a supplementation reduced ammonia production. L. plantarum 73a alone or in combination with B. animalis subsp. lactis INL1 are potential probiotic candidates for the management of infant obesity.

Evaluation of Swallowing Related Muscle Activity by Means of Concentric Ring Electrodes.

Surface electromyography (sEMG) can be helpful for evaluating swallowing related muscle activity. Conventional recordings with disc electrodes suffer from significant crosstalk from adjacent muscles and electrode-to-muscle fiber orientation problems, while concentric ring electrodes (CREs) offer enhanced spatial selectivity and axial isotropy. The aim of this work was to evaluate CRE performance in sEMG recordings of the swallowing muscles. Bipolar recordings were taken from 21 healthy young volunteers when swallowing saliva, water and yogurt, first with a conventional disc and then with a CRE. The signals were characterized by the root-mean-square amplitude, signal-to-noise ratio, myopulse, zero-crossings, median frequency, bandwidth and bilateral muscle cross-correlations. The results showed that CREs have advantages in the sEMG analysis of swallowing muscles, including enhanced spatial selectivity and the associated reduction in crosstalk, the ability to pick up a wider range of EMG frequency components and easier electrode placement thanks to its radial symmetry. However, technical changes are recommended in the future to ensure that the lower CRE signal amplitude does not significantly affect its quality. CREs show great potential for improving the clinical monitoring and evaluation of swallowing muscle activity. Future work on pathological subjects will assess the possible advantages of CREs in dysphagia monitoring and diagnosis.

Risk clusters of COVID-19 transmission in northeastern Brazil: prospective space-time modelling.

This study aimed to analyse the trend and spatial-temporal clusters of risk of transmission of COVID-19 in northeastern Brazil. We conducted an ecological study using spatial and temporal trend analysis. All confirmed cases of COVID-19 in the Northeast region of Brazil were included, from 7 March to 22 May 2020. We used the segmented log-linear regression model to assess time trends, and the local empirical Bayesian estimator, the global and local Moran indexes for spatial analysis. The prospective space-time scan statistic was performed using the Poisson probability distribution model. There were 113 951 confirmed cases of COVID-19. The average incidence rate was 199.73 cases/100 000 inhabitants. We observed an increasing trend in the incidence rate in all states. Spatial autocorrelation was reported in metropolitan areas, and 178 municipalities were considered a priority, especially in the states of Ceará and Maranhão. We identified 11 spatiotemporal clusters of COVID-19 cases; the primary cluster included 70 municipalities from Ceará state. COVID-19 epidemic is increasing rapidly throughout the Northeast region of Brazil, with dispersion towards countryside. It was identified high risk clusters for COVID-19, especially in the coastal side.

Perfil de ácidos graxos do leite de vacas Holandês x Gir alimentadas com silagem de milho e concentrado contendo ou não glicerina bruta / Milk fatty acid profile from Holstein x Gyr cows fed corn silage and concentrate containing or not crude glycerin

O objetivo deste estudo foi avaliar o perfil de ácidos graxos (AG) do leite de vacas alimentadas com dietas à base de silagem de milho contendo 0% e 8,9% de glicerina bruta (GB) na matéria seca (MS). Foram utilizadas 18 vacas Holandês x Gir com 48±18 dias em lactação, produzindo 19,8±4,9kg/dia de leite. Utilizou-se delineamento de blocos ao acaso, com nove vacas/tratamento e duas medidas repetidas no tempo, com os resultados analisados por modelos mistos. A inclusão de GB na dieta não alterou a ingestão de MS, mas reduziu os consumos dos AG oleico, linoleico e α-linolênico. Os teores dos AG mirístico, palmítico, rumênico, vacênico, esteárico, oleico, linoleico, α-linolênico e CLA trans-10 cis-12 na gordura do leite foram semelhantes entre dietas. A inclusão de GB reduziu os teores dos AG elaídico e C18:1 trans-10 e aumentou os teores dos AG de cadeia ímpar linear e do ácido láurico. Não houve efeito da inclusão da GB sobre os índices de aterogenicidade e trombogenicidade da gordura do leite. Concluiu-se que a inclusão de glicerina bruta em dieta à base de silagem de milho não afetou a qualidade nutricional da gordura do leite de vacas Holandês x Gir.(AU)

The objective of this study was to evaluate the milk fatty acid (FA) composition of cows fed corn silage-based diets containing 0% and 8.9% of crude glycerin (GB) on a dry matter (DM) basis. Eighteen Holstein x Gyr cows with 48±18 days in milk and producing 19.8±4.9kg milk/day were used in the study. The experimental design was a randomized block with nine cows per treatment and two repeated measures. Results were analyzed using mixed models. The milk fat contents of myristic, palmitic, rumenic, vaccenic, estearic, oleic, linoleic, α-linolenic, and trans-10 cis-12 CLA were similar between diets. Dietary inclusion of GB decreased elaidic and trans-10 C18:1, and increased lauric acid and odd linear-chain FA contents in milk fat. Both atherogenicity and trombogenicity indices were unaffected by GB inclusion. It was concluded that GB inclusion in corn silage-based diets had no effect on the nutritional quality of milk fat from Holstein x Gyr dairy cows.(AU)

Exceptional preservation of mid-Cretaceous marine arthropods and the evolution of novel forms via heterochrony.

Evolutionary origins of novel forms are often obscure because early and transitional fossils tend to be rare, poorly preserved, or lack proper phylogenetic contexts. We describe a new, exceptionally preserved enigmatic crab from the mid-Cretaceous of Colombia and the United States, whose completeness illuminates the early disparity of the group and the origins of novel forms. Its large and unprotected compound eyes, small fusiform body, and leg-like mouthparts suggest larval trait retention into adulthood via heterochronic development (pedomorphosis), while its large oar-like legs represent the earliest known adaptations in crabs for active swimming. Our phylogenetic analyses, including representatives of all major lineages of fossil and extant crabs, challenge conventional views of their evolution by revealing multiple convergent losses of a typical "crab-like" body plan since the Early Cretaceous. These parallel morphological transformations may be associated with repeated invasions of novel environments, including the pelagic/necto-benthic zone in this pedomorphic chimera crab.

Suppression of the SOS response modifies spatiotemporal evolution, post-antibiotic effect, bacterial fitness and biofilm formation in quinolone-resistant Escherichia coli.

Background: Suppression of the SOS response has been proposed as a therapeutic strategy for potentiating quinolones against susceptible, low-level quinolone-resistant (LLQR) and resistant Enterobacteriaceae. Objectives: To monitor the functionality of the SOS response in the evolution towards clinical quinolone resistance and study its impact on the evolution of spatiotemporal resistance. Methods: An isogenic collection of Escherichia coli (derived from the strain ATCC 25922) carrying combinations of chromosomally and plasmid-mediated quinolone resistance mechanisms (including susceptible, LLQR and resistant phenotypes) and exhibiting a spectrum of SOS activity was used. Relevant clinical parameters such as mutation rate, mutant prevention concentration (MPC), bacterial fitness, biofilm formation and post-antibiotic effect (PAE) were evaluated. Results: Inactivating the SOS response (recA deletion) led to a decrease in mutation rate (∼103 fold) in LLQR compared with WT strains at ciprofloxacin concentrations of 1 mg/L (the EUCAST breakpoint for resistance) and 2.5 mg/L (Cmax), as well as a remarkable delay in the spatiotemporal evolution of quinolone resistance. For all strains, there was an 8-fold decrease in MPC in RecA-deficient strains, with values for LLQR strains decreasing below the Cmax of ciprofloxacin. Inactivation of the SOS response reduced competitive fitness by 33%-50%, biofilm production by 22%-80% and increased the PAE by ∼3-4 h at sub-MIC concentrations of ciprofloxacin. Conclusions: Our data indicate that suppression of the SOS response affects key bacterial traits and is a promising strategy for reversing and tackling the evolution of antibiotic resistance in E. coli, including low-level and resistant phenotypes at therapeutic quinolone concentrations.

Ablación cardiaca auricular: estrategias guiadas por el mapeo de electrogramas / Catheter Ablation for Atrial Fibrillation: Electrogram-Guided Methods

Resumen La ablación por radiofrecuencia se ha constituido como la técnica más utilizada para el tratamiento intervencionista de la fibrilación auricular. El aislamiento eléctrico de venas pulmonares se ha convertido en el procedimiento convencional, principalmente en pacientes con fibrilación auricular paroxística. Sin embargo, la tasa de éxito mediante esta técnica en pacientes con fibrilación auricular persistente es alrededor del 50%. Aunque se han propuesto diversas estrategias para guiar al electrofisiólogo en los procedimientos de ablación, estudios recientes muestran que la generación de líneas de ablación adicionales guiadas anatómicamente o mediante mapeo de electrogramas complejos fragmentados, no mejora la tasa de éxito del procedimiento convencional de aislamiento de venas pulmonares. En esta revisión, se consideran las limitaciones que representan los métodos de mapeo electrofisiológicos actuales, las nuevas estrategias de evaluación de los electrogramas y los métodos de procesamiento de señales que se ven propuestos en el futuro más inmediato, para guiar los procedimientos de ablación particularmente en pacientes con fibrilación auricular persistente.

Abstract Radiofrequency catheter ablation has evolved into an effective treatment option for drug-resistant patients with atrial fibrillation. Electrical isolation of the pulmonary veins has become the standard ablation strategy mainly in patients with paroxysmal atrial fibrillation. However, the success rate of pulmonary veins isolation is about 50% in patients with persistent atrial fibrillation. Although different strategies to guide the electrophysiologist in ablation procedures have been proposed. Recent studies show that the generation of additional ablation lines guided anatomically or by fragmented complex electrograms mapping does not improve the success rate of the conventional pulmonary veins isolation procedure. In this review, we describe the limitations of current electrophysiological mapping methods, the new electrogram evaluation strategies and the signal processing methods that are proposed in the immediate future, to guide ablation procedures, particularly in patients with atrial fibrillation persistent.

Caracterización y Clasificación de Señales de Auscultación Cervical Adquiridas con Estetoscopio para Detección Automática de Sonidos Deglutorios / Characterization and Classification of Cervical Auscultation Signals Acquired with Stethoscope for Automatic Detection of Swallowing Sound

Resumen: La evaluación automática de sonidos de auscultación cervical (AC) es una herramienta no invasiva para evaluación de la deglución. Sin embargo, los eventos deglutorios pueden verse enmascarados por fuentes de ruido. Este trabajo propone una metodología de caracterización y clasificación de señales de AC con alta resolución temporal a partir de estetoscopio, para discriminar entre sonidos deglutorios y asociados a ruido. Se adquirieron señales de AC en 10 sujetos sanos durante tres pruebas: toma de líquido, pronunciación del fonema /a/ y aclaramiento de garganta. Se extrajeron características de la señal de AC basadas en coeficientes cepstrales en la escala Mel, transformada wavelet discreta y entropía de Shannon. Las características con mayor relevancia fueron utilizadas como entrada a una máquina de vectores de soporte. Utilizando ventanas de 60 ms - alta resolución temporal - y validación cruzada, se obtuvieron exactitudes del 97.7% para detección de eventos acústicos y 91.7% para sonidos deglutorios. El método propuesto permite clasificación de sonidos deglutorios utilizando estetoscopio -dispositivo común en la práctica clínica- con exactitud comparable a otros trabajos que tienen menor resolución temporal o que utilizan otro tipo de sensores. Este trabajo constituye una primera etapa en el desarrollo de un algoritmo robusto para clasificación de sonidos deglutorios asociados a desórdenes de la deglución, a partir de auscultación cervical, para fines de diagnóstico automático.

Abstract: Automatic evaluation of cervical auscultation sounds (AC) is a non-invasive tool for swallowing assessment. However, the swallowing events could be perturbed by acoustic noise. This paper proposes a methodology of characterization and classification of AC signals acquired by stethoscope with high temporal resolution, in order to discriminate between swallowing sounds and other acoustic noise. AC signals from 10 healthy individuals were acquired with stethoscope during three tasks: liquid ingestion, phoneme /a/ pronunciation and throat clearing. Features based in Mel frequency cepstral coefficients, discrete wavelet transform and Shannon entropy, were extracted. Features with highest Fisher's discriminant ratio were used as input of a support vector machine. By application of 60 ms windows and cross validation, the obtained accuracies were 97.7% for acoustic event detection and 91.7% for swallowing sound detection. The proposed method allows classification swallowing sounds with higher temporal resolution­ than other works but with comparable accuracy. Furthermore, the use of stethoscope could lead to better acceptation than other sensors by physicians, because it is a common device in clinical practice. This work is a first stage in the development of a robust classification algorithm for sounds in swallowing disorders, oriented to automatic diagnosis.

Accuracy of cotinine serum test to detect the smoking habit and its association with periodontal disease in a multicenter study.

BACKGROUND: The validity of the surveys on self-reported smoking status is often questioned because smokers underestimate cigarette use and deny the habit. It has been suggested that self-report should be accompanied by cotinine test. This report evaluates the usefulness of serum cotinine test to assess the association between smoking and periodontal status in a study with a large sample population to be used in studies with other serum markers in epidemiologic and periodontal medicine researches. MATERIAL AND METHODS: 578 patients who were part of a multicenter study on blood biomarkers were evaluated about smoking and its relation to periodontal disease. Severity of periodontal disease was determinate using clinical attachment loss (CAL). Smoking was assessed by a questionnaire and a blood sample drawn for serum cotinine determination. RESULTS: The optimal cut-off point for serum cotinine was 10 ng/ml. Serum cotinine showed greater association with severity of CAL than self-report for mild-moderate CAL [OR 2.03 (CI95% 1.16-3.53) vs. OR 1.08 (CI95% 0.62-1.87) ] advanced periodontitis [OR 2.36 (CI95% 1.30- 4.31) vs. OR 2.06 (CI95% 0.97-4.38) ] and extension of CAL > 3 mm [ OR 1.78 (CI95% 1.16-1.71) vs. 1.37 (CI95% 0.89-2.11)]. When the two tests were evaluated together were not shown to be better than serum cotinine test. CONCLUSIONS: Self-reported smoking and serum cotinine test ≥ 10ng/ml are accurate ,complementary and more reliable methods to assess the patient's smoking status and could be used in studies evaluating serum samples in large population and multicenter studies. CLINICAL RELEVANCE: The serum cotinine level is more reliable to make associations with the patient's periodontal status than self-report questionnaire and could be used in multicenter and periodontal medicine studies.