Validación de escalas multiparamétricas de predicción de riesgo de muerte súbita en pacientes con síndrome de Brugada y estudio electrofisiológico / Validation of multiparametric approaches for the prediction of sudden cardiac death in patients with Brugada syndrome and electrophysiological study

Introducción y objetivos: Se han desarrollado puntuaciones multiparamétricas para una mejor estratificación del riesgo en el síndrome de Brugada (SBr). Nuestro objetivo es validar 3 abordajes multiparamétricos (las escalas Delise, Sieira y Shanghai BrS) en una cohorte de pacientes con síndrome de Brugada y estudio electrofisiológico (EEF). Métodos: Pacientes diagnosticados de SBr y con un EEF previo entre 1998-2019 en 23 hospitales. Se utilizaron análisis mediante estadístico C y modelos de regresión de riesgos proporcionales de Cox. Resultados: Se incluyó en total a 831 pacientes con una media de edad de 42,8±13,1 años; 623 (75%) eran varones; 386 (46,5%) tenían patrón electrocardiográfico (ECG) tipo 1; 677 (81,5%) estaban asintomáticos y 319 (38,4%) tenían un desfibrilador automático implantable. Durante un seguimiento de 10,2±4,7 años, 47 (5,7%) sufrieron un evento cardiovascular. En la cohorte total, un ECG tipo 1 y síncope fueron predictivos de eventos arrítmicos. Todas las puntuaciones de riesgo se asociaron significativamente con los eventos. Las capacidades discriminatorias de las 3 escalas fueron discretas (particularmente al aplicarlas a pacientes asintomáticos). La evaluación de las puntuaciones de Delise y Sieira con diferente número de extraestímulos (1 o 2 frente a 3) no mejoró sustancialmente el índice c de predicción de eventos. Conclusiones: En el SBr, los factores de riesgo clásicos como el ECG y el síncope previo predicen eventos arrítmicos. El número de extraestímulos necesarios para inducir arritmias ventriculares influye en las capacidades predictivas del EEF. Las escalas que combinan factores de riesgo clínico con EEF ayudan a identificar las poblaciones con más riesgo, aunque sus capacidades predictivas siguen siendo discretas tanto en población general con SBr como en pacientes asintomáticos (AU)

Introduction and objectives: Multiparametric scores have been designed for better risk stratification in Brugada syndrome (BrS). We aimed to validate 3 multiparametric approaches (the Delise score, Sieira score and the Shanghai BrS Score) in a cohort with Brugada syndrome and electrophysiological study (EPS). Methods: We included patients diagnosed with BrS and previous EPS between 1998 and 2019 in 23 hospitals. C-statistic analysis and Cox proportional hazard regression models were used. Results: A total of 831 patients were included (mean age, 42.8±13.1; 623 [75%] men; 386 [46.5%] had a type 1 electrocardiogram (ECG) pattern, 677 [81.5%] were asymptomatic, and 319 [38.4%] had an implantable cardioverter-defibrillator). During a follow-up of 10.2±4.7 years, 47 (5.7%) experienced a cardiovascular event. In the global cohort, a type 1 ECG and syncope were predictive of arrhythmic events. All risk scores were significantly associated with events. The discriminatory abilities of the 3 scores were modest (particularly when these scores were evaluated in asymptomatic patients). Evaluation of the Delise and Sieira scores with different numbers of extra stimuli (1 or 2 vs 3) did not substantially improve the event prediction c-index. Conclusions: In BrS, classic risk factors such as ECG pattern and previous syncope predict arrhythmic events. The predictive capabilities of the EPS are affected by the number of extra stimuli required to induce ventricular arrhythmias. Scores combining clinical risk factors with EPS help to identify the populations at highest risk, although their predictive abilities remain modest in the general BrS population and in asymptomatic patients (AU)

Coherent imager module with a large field of view for synthetic aperture interferometry applications.

Optical areal profilometry of large precision-engineered surfaces require high-resolution measurements over large fields of view. Synthetic Aperture Interferometry (SAI) offers an alternative to the conventional approach of stitching small fields of view (FOV) obtained with Coherent Scanning Interferometry (CSI) using high-NA objectives. In SAI, low-resolution digital holograms are recorded for different illumination and observation directions and they are added coherently to produce a high-resolution reconstruction over a large FOV. This paper describes the design, fabrication and characterization of a large FOV, compact and low-cost coherent imager (CI) as a building block of a coherent sensor array for a SAI system. The CI consists of a CMOS photodetector array with 1.12 µm pixel pitch, a square entrance pupil and a highly divergent reference beam that emerges from a pinhole milled with a focused ion beam on the cylindrical cladding at the tip of an optical fibre. In order to accurately reconstruct the digital holograms, the wavefront of the reference beam is estimated by localizing the reference source relative to the photodetector array. This is done using an optimization approach that simultaneously reconstructs plane waves that reach the aperture from 121 different illumination directions and guarantees a phase root-mean-squared (RMS) error of less than a fifth of the wavelength across the CI entrance pupil at a boundary of the FOV. The CI performance is demonstrated with a holographic reconstruction of a 0.110 m wide object placed at a distance of 0.085 m, i.e. a FOV = ±0.57 rad, the highest reported to date with a holographic camera.

Leeches from Mexico City, remnants of the ancient lake.

Genetic barcodes (partial sequences of the mitochondrial cytochrome c oxidase subunit I) were generated for freshwater leeches that inhabit the Mexico Basin, upon which Mexico City and its metropolitan area have developed. Once a continuous lake, the basin has passed through continuous events of artificial desiccation in the last 500 years so that it is currently conformed by a few and highly modified and polluted isolated freshwater bodies. Six species of leeches from three families were collected in five localities. Current sequence databases were able to determine five of the six species collected for this study with the only exception of Haemopis caballeroi, for which no sequence data are available in public repositories. Taxonomic assignment of cocoons was possible via comparison of barcode sequences. We discuss the presence of a population of Erpobdella ochoterenai in Tecocomulco Lake that bares high genetic divergence from its conspecifics, which may indicate it is an undescribed species.

Ablation of frequent premature ventricular complex in an athlete.

Premature ventricular complex are common findings in the exam of many athletes. There is no extensive scientific evidence in the management of this situation particularly when associated with borderline contractile function of the left ventricle. In this case report, we present a 35-year-old asymptomatic healthy athlete with high incidence (over 10,000 beats in 24 h) of premature ventricular complex and left ventricular dilatation with dysfunction, which persisted after a resting period of 6 months without training. We performed radiofrequency ablation of the premature ventricular complex focus. After 1-year follow-up, he was asymptomatic without arrhythmia and the left ventricle normalized its size and function as shown by echocardiogram and cardiac magnetic resonance.

Bloch modes at the surface of a photonic crystal interacting with a waveguide.

We theoretically studied the influence of an infinite set of waveguides on the evanescent field of Bloch waves at the surface of a one-dimensional photonic crystal (PC) excited by a TE Gaussian beam undergoing total internal reflection. The set of waveguides is regarded as a periodic inhomogeneous medium with period a. Numerical results are presented for the case in which a is greater than λ, which is the wavelength used to excite the surface mode. When the waveguide tip is very close to the surface of the PC, a fraction of the surface wave is reflected by the tip, producing an interference pattern that can be observed in the near field. In this case, the system simulates scanning tunneling optical microscopy in 2D geometry, and an image of the field distribution of the surface mode is obtained by quantifying the flux energy throughout the waveguide.

Photonic crystal to photonic crystal surface modes: narrow-bandpass filters.

The properties of surface modes present in the junction of two different one-dimensional photonic crystals placed in series are studied to assess the possibility of applying them in the design of narrow-bandpass filters. To design bandpass filters that are similar in many respects to multiple-cavity Fabry-Perot filters, we also consider the coupling conditions for these surface modes for multiple photonic crystals placed in series to form a multiple-junction system.

Photonic crystal sensor based on surface waves for thin-film characterization.

A new sensor based on optical surface waves in truncated one-dimensional photonic crystals is proposed for use in determining the optical properties of metallic or dielectric thin films and bulk media. Specifically, the method of optical characterization takes into account the changes that the surface waves of a layered structure undergo when either a thin film of arbitrary material is added at the surface or the optical properties of transmission medium change. For the surface-wave excitation the Kretschmann configuration used in attenuated total reflectance is employed.

Absence of shedding of two B. abortus strains in goats after vaccination with live vaccines.

The objective of this study was to determine if B. abortus rough mutant strains RB51 and rfbK are eliminated in goat milk. Thirty milk goats were divided into two groups. Group I was inoculated with 4x10(10) cfu/ml of B.abortus RB51 strain and Group II with 1x10(9) cfu/ml of B. abortus rfbK strain by subcutaneous route in the right axilary region. Milk samples were taken aseptically on a daily basis for the first 30 days and weekly for the second and third months. The samples were inoculated on Farrell's media and incubated under 5-10% CO(2) at 37 degrees C for 10 days. The suspicious colonies were recultured in Farrell's media. There were no isolations of bacteria with characteristics of Brucella from any of the milk samples collected during 90 days of the study. It was concluded that neither of the strains used at these doses were eliminated by milk in goats inoculated during lactation.

[The seeding of porcine endothelial cells on a polytetrafluoroethylene (PTFE) substrate. An experimental study]. / Siembra de células endoteliales porcinas sobre un substrato de politetrafluoroetileno (PTFE). Estudio experimental.

The endotely of the vascular wall represents a natural antithrombogenic layer in intimal contact with the bloody flow. The waited success of the artificial prosthesis as replacers of minor vessels was not reached. Basically, its poor results were caused by the lake of endothelialization on the prothesical material. A cellular lap on the prosthesis, previously to the implant, could be a good resolution to this problem. If we studied the possibility to obtain a stable, endothelial monolayer "in vitro" before to the "in vivo" implant of the vascular prosthesis. We studied the role of fibronectin as a mediator between the substract and the endothelial cell. Changes on fibronectin when it is added on the culture medium were also analyzed. Although fibronectin has some positive effects as a biologic "glue" previously to the implant to the prosthesis, our results show that after the implant, fibronectin could cause a toxic effect on the adherence and survival of the endothelial cells.

[Disposable obturator system for colostomized patients. Experience with thirty patients over one year]. / Système d'obturateur jetable pour patients colostomisés. Expérience sur trente malades en un an.

The objective of this study, conducted according to a specially designed protocol, was to evaluate the efficacy of a disposable obturator in patients with an artificial anus. The obturator was tested for 1 year in 30 patients with a colostomy. The characteristics of these patients, the system adopted for training and follow-up and the results obtained are analysed. The disposable stopper gave favourable results as a contention system; the tolerance was good and no adverse effects were observed. In particular, the patients appreciated the absence of noise and odour and the security offered by this system. The contention systems in current use are reviewed followed by a discussion based on their experience and their results.