Films of biopolymers, pectin and gellan, enriched with natamycin and clove essential oils for the packaging of Corn tortilla: Protection against Staphylococcus aureus and Candida parapsilosis.

It was investigated the microbial protection of corn tortilla, traditional Mexican food with high acceptance, for food safety. We elaborated a functional film (FF) prepared with 0.4% (w/v) gellan gum, 2% (w/v) citrus pectin, 0.5% (w/v) glycerol, 0.0003% (w/v) natamycin, 0.03% (v/v) essential clove oils, and 0.1% (v/v) tween 80. The FF impeded the growth of indicator microorganisms in corn tortilla medium: Staphylococcus aureus (i.e., 35 °C, 50% RH, 7 days) and Candida parapsilosis (i.e., 27 °C, 42% RH, 7 days; and 9 °C, 95% RH, 30 days). In packaged artisanal corn tortilla storage at 22 °C and 50% RH for 30 days, the FF-treatments showed 5.5 log CFU/g total aerobes and 4.8 log CFU/g yeasts and moulds, being two and three logs lower than the concentrations recorded in the controls with no film, respectively. Some physical-mechanical properties of FF were Young's modulus, 500 MPa; elongation at break, 10%; stress at break, 18.5 MPa; oxygen permeability, 4 × 10-13 g m Pa-1 s-1 m-2; and water vapour permeability, 4.8 × 10-11 g m Pa-1 s-1 m-2. Also, the sensory evaluation of wrapped tortilla suggested no negative effects. The obtained results envisage potential food-packaging applications with the elaborated films.

A randomized clinical trial of prolonged exposure and applied relaxation for the treatment of Latinos with posttraumatic stress disorder.

Robust evidence supports the use of prolonged exposure therapy (PE) as a first-line treatment for posttraumatic stress disorder (PTSD). However, Latinos have not benefitted equally from advancements in the treatment of PTSD and continue to face barriers to receiving care. There is consensus that it is necessary to support the expansion of high-quality culturally and linguistically appropriate treatment to address disparities experienced by racial and ethnic minorities in behavioral health care. The current study was a randomized controlled trial comparing a culturally adapted PE intervention with applied relaxation (AR) among Spanish-speaking Latinos with PTSD in Puerto Rico. Eligible participants (N = 98) were randomly assigned to PE (n = 49) or AR (n = 49). Both treatments included 12-15 weekly sessions each lasting 60-90 min. The primary outcome, clinician-rated PTSD symptom severity, was assessed using the Clinician-Administered PTSD Scale for DSM-5 at baseline, posttreatment, and 3-month follow-up. Secondary outcomes were assessed using the Patient Health Questionnaire and State-Trait Anxiety Inventory. Results showed a large within-group effect of treatment on PTSD symptoms, PE: d = 1.29, 95% CI [1.12, 2.05]; AR: d = 1.38, 95% CI [1.21, 2.19]. The between-group effect on PTSD symptoms was small, d = -0.09, 95% CI [-0.48, 0.31]. Participants in both treatment conditions reported significant decreases in PTSD symptoms from baseline to follow-up; additionally, significant within-group reductions in depression and anxiety symptoms were observed. These findings underscore the potential benefit of PE and AR for the treatment of Spanish-speaking Latinos with PTSD.

Toward understanding the signals of bacteriocin production by Streptococcus spp. and their importance in current applications.

Microorganisms have developed quorum sensing (QS) systems to detect small signaling molecules that help to control access to additional nutrients and space in highly competitive polymicrobial niches. Many bacterial processes are QS-regulated; two examples are the highly related traits of the natural genetic competence state and the production of antimicrobial peptides such as bacteriocins. The Streptococcus genus is widely studied for its competence and for its ability to produce bacteriocins, as these antimicrobial peptides have significant potential in the treatment of infections caused by multiple-resistant pathogens, a severe public health issue. The transduction of a two-component system controls competence in streptococci: (1) ComD/E, which controls the competence in the Mitis and Anginosus groups, and (2) ComR/S, which performs the same function in the Bovis, Mutans, Salivarius, and Pyogenic groups. The cell-to-cell communication required for bacteriocin production in the Streptococcus groups is controlled mainly by a paralog of the ComD/E system. The relationships between pheromone signals and induction pathways are related to the bacteriocin production systems. In this review, we discuss the recent advances in the understanding of signaling and the induction of bacteriocin biosynthesis by QS regulation in streptococci. This information could aid in the design of better methods for the development and production of these antimicrobial peptides. It could also contribute to the analysis and emerging applications of bacteriocins in terms of their safety, quality, and human health benefits.

Pectin-gellan films intended for active food packaging: release kinetics of nisin and physico-mechanical characterization.

Films were prepared by casting 2% w/v apple pectin, 0.5% w/v low-acyl gellan and 2.2% w/v glycerol as plasticizer. Bioactive film (BF, films with 3912 International Units (IU) nisin/cm2) and control films (CF, films without nisin) were elaborated. The objective was to analyze the release kinetics of nisin from films to a food model, to determine the period of film bioactivity and potential use as antimicrobial packaging. The release of nisin from BF to a food model was determined at 5 °C and 30 °C. The release kinetics of nisin was fitted to the analytical solution of the Fick's second law for an infinite plate. The diffusion coefficients of nisin (D) were 5.22 × 10-14 and 7.36 × 10-14 m2/s for 5 °C and 30 °C, respectively. Besides, both films were characterized in their mechanical properties and gas permeabilities [oxygen (PO2) and water vapour permeability (WVP)]. The mechanical properties were reduced by the nisin incorporation, whereas PO2 was increased, and no significant effect on WVP was observed.

Production of entomopathogenic nematodes in submerged monoxenic culture: A review.

Monoxenic liquid culture is the most suitable technology for scaling up to industrial production of entomopathogenic nematodes (EPNs); however, the variability of the yield production remains a current problem in the process. The aim of this study was to analyze the parameters and criteria for EPN production in liquid culture based on scientific and technological knowledge from the last two decades. While experimental research has permitted the yield production of Heterorhabditis bacteriophora (362 × 103 infective juveniles [IJs]/ml) and Steinernema carpocapsae (252 × 103 IJs/ml), simultaneously, theoretical approaches have contributed to the understanding of the culture process, based on biological parameters of the bacterium-nematode complex and hydrodynamic and rheological parameters of the complex gas-liquid-solid system. Under this interdisciplinary research approach, bioprocess and biosystem engineering can contribute to design the various control strategies of the process variables, increase the productivity, and reduce the variability that until now distinguishes the in vitro production of EPNs by the liquid culture.

Bacteriocin encapsulation for food and pharmaceutical applications: advances in the past 20 years.

The encapsulation of bacteriocins from lactic acid bacteria has involved several methods to protect them from unfavourable environmental conditions and incompatibilities. This review encompasses different methods for the encapsulation of bacteriocins and their applications in both food and pharmaceutical fields. Based on the bibliometric analysis of publications from well-reputed journals including different available patents during the period from 1996 to 2017, 135 articles and 60 patents were collected. Continent-wise contributions to the bacteriocins encapsulation research were carried out by America (52%), Asia (29%) and Europe (19%); with the United States of America, Brazil, Thailand and Italy the countries with major contributions. Till date, different methods proposed for encapsulation have been (i) Film coatings (50%), (ii) Liposomes (23%), (iii) Nanofibers (22%) and (iv) Nanoparticles (4%). Bacteriocins encapsulation methods frequently carried out in food protection (70%); while in the pharmaceutical field, 30% of the research was conducted on multi drug resistant therapy.

Mexican Registry of Cardiomyopathies: baseline data, diagnostic strategies, and treatment approaches in Mexico.

Objectives: The study aimed to know the clinical, demographic, diagnostic, and treatments characteristics in patients with cardiomyopathies in Mexico. Methods: The Mexican Registry of Cardiomyopathies (REMEMI) is an observational, prospective and national study of patients with cardiomyopathies, which includes: Dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM) and arrhythmogenic cardiomyopathy of the right ventricle (ARVC). Results: A total of 1026 patients from most states of the Mexican Republic (19) were included, with 494 corresponding to DCM, 490 to HCM, 35 to RCM, and seven to ARVC. We found significant differences between the various cardiomyopathy phenotypes (p < 0.05) in the coexistence with diabetes, use of implantable defibrillator, presence of ventricular tachycardia, and NYHA functional class ≥ 1. There were no significant differences in age and predominant gender between each one. When analyzing by phenotype, we found that patients with HCM have limited use of diagnostic methods considered indispensable, such as cardiac magnetic resonance, Holter monitoring, and genetic testing in patients and their relatives. Conclusion: Seeking contemporary information through observational registries in Mexico is a valuable opportunity to understand the characteristics of the methods used in the study and treatment of diseases such as cardiomyopathies by Mexican physicians. It can provide information for the implementation of management guidelines and strategies to disseminate findings to improve healthcare in our country.

Objetivo: Conocer las características clínicas y demográficas, así como las herramientas diagnósticas y tratamientos utilizados en pacientes con miocardiopatías en México. Métodos: El Registro Mexicano de Miocardiopatías (REMEMI) es un estudio observacional, prospectivo y nacional de pacientes con diagnóstico de miocardiopatía, que incluye: miocardiopatía dilatada (MCD), miocardiopatía hipertrófica (MCH), miocardiopatía restrictiva (MCR) y miocardiopatía arritmogénica del ventrículo derecho (MAVD). Resultados: Se incluyó un total de 1026 pacientes provenientes de la mayoría de los estados de la República Mexicana (19), de los cuales 494 corresponden a MCD, 490 a MCH, 35 a MCR y 7 a MAVD. Encontramos diferencias significativas entre los diversos fenotipos de miocardiopatías (p < 0.05) en la coexistencia con diabetes, empleo de desfibrilador implantable, presencia de taquicardia ventricular y la clase funcional de la NYHA ≥ 1. No hubo diferencias significativas en la edad y sexo predominante entre cada uno. Al analizar por fenotipo encontramos que la MCH tienen poco empleo de métodos diagnósticos considerados como indispensables como la resonancia magnética cardiaca, el monitoreo Holter y el estudio genético en los pacientes y sus familiares. Conclusión: La búsqueda de información contemporánea a través de registros observacionales en México es una buena oportunidad para conocer las características de los métodos empleados en el estudio y tratamiento de enfermedades como las miocardiopatías por médicos mexicanos, y puede ofrecernos información para la implementación de guías de manejo y estrategias de difusión de los hallazgos para así mejorar el cuidado de la salud en nuestro país.

Coumel tachycardia in children.

BACKGROUND: Coumel tachycardia is an infrequent form of supraventricular tachycardia (SVT) that usually occurs in infants and children. It is a tachycardia mediated by an accessory pathway with retrograde slow conduction that explains the classic ECG pattern with long RP' interval and negative P waves in leads II, III, and aVF. In this study, we describe the clinical course and management of Coumel tachycardia in children. CASE REPORT: We conducted a retrospective review of five consecutive pediatric patients, mean age 11 ± 3 years (range 6 to 14). The first episode of SVT was at a mean age of 10.4 ± 4.8 years (range 2 to 14) with a mean evolution of 7.4 ± 9.4 months (range 1 to 24). Pharmacological therapy was unsuccessful despite the combination of antiarrhythmic drugs. The tachycardia was incessant with a density > 85% by 24-hour Holter monitoring; one patient developed tachycardia-induced cardiomyopathy. All children underwent successful radiofrequency catheter ablation, mean 5 ± 3 applications (range 1 to 8) with a single session and with no complications. After a mean follow-up of 24 ± 16 months, all patients were asymptomatic and recurrence-free without antiarrhythmic treatment. CONCLUSIONS: Coumel tachycardia is clinically persistent and usually refractory to antiarrhythmic treatment with substantial risk of tachycardia-mediated cardiomyopathy. Catheter ablation is effective and safe in children; thus, it should be indicated promptly and based on individual selection.

INTRODUCCIÓN: La taquicardia de Coumel es una forma poco frecuente de taquicardia supraventricular que suele presentarse en lactantes. Es una taquicardia mediada por una vía accesoria de conducción lenta retrógrada que explica el patrón ECG clásico con intervalo RP' largo y ondas P negativas en las derivaciones II, III y aVF. En este trabajo se describe el curso clínico y el manejo de la taquicardia de Coumel en niños. CASO CLÍNICO: Se llevó a cabo una revisión retrospectiva de cinco pacientes pediátricos consecutivos, con una media de edad de 11 ± 3 años (intervalos 6 a 14). El primer episodio de taquicardia 10.4 ± 4.8 años con evolución de 7.4 ± 9.4 meses. El tratamiento farmacológico fue ineficaz a pesar de la combinación de antiarrítmicos. La taquicardia era incesante con una densidad > 85% por Holter-24h; un paciente desarrolló miocardiopatía inducida por taquicardia. Todos los niños fueron sometidos a ablación con catéter y radiofrecuencia con éxito, y un promedio de 5 ± 3 aplicaciones en una sola sesión y sin complicaciones. Después de un seguimiento de 24 ± 16 meses, todos los pacientes fueron asintomáticos y libres de recurrencia sin tratamiento antiarrítmico. CONCLUSIONES: La taquicardia de Coumel es clínicamente persistente y generalmente refractaria al tratamiento antiarrítmico con un riesgo sustancial de miocardiopatía mediada por taquicardia. La ablación con catéter es eficaz y segura en niños, por lo que debe indicarse de forma temprana y en lactantes de una selección individual.

Natural antimicrobial systems protected by complex polyhydroxyalkanoate matrices for food biopackaging applications - A review.

Interest is growing in entrapping natural antimicrobial compounds (NACs) within polyhydroxyalkanoates (PHAs) to produce active food-biopackaging systems. PHAs are versatile polymeric macromolecules that can protect NAC activity by entrapment. This work reviews 75 original papers and 18 patents published in the last 11 years concerning PHAs as matrices for NACs to summarize the physicochemical properties, release, and antimicrobial activities of systems fabricated from PHAs and NACs (PHA/NAC systems). PHA/NAC systems have recently been used as active food biopackaging systems to inactivate foodborne pathogens and prolong food shelf life. PHAs protect NACs by increasing the degradation temperature of some NACs and decreasing their loss of mass when heated. Some NACs also transform the PHA/NAC systems into more thermostable, flexible, and resistant when interacting with PHAs while also improving the barrier properties of the systems. NAC release and activity are also prolonged when NACs are trapped within PHAs. PHA/NAC systems, therefore, represent ecologically friendly materials with promising applications.

Bacteriocins Produced by LAB Isolated from Cheeses within the Period 2009-2021: a Review.

A survey is presented concerning original research articles published in well-reputed scientific journals on the isolation of lactic acid bacteria (LAB) from cheeses worldwide, where researchers evaluated the bacteriocin production by such isolates in searching for novel functional peptides that can exhibit potential for biotechnological applications. Seventy-one articles were published in the period of study, with contributions being American (45%), Asiatic (28%), and European (21%), being Brazil-USA-Mexico, Turkey-China, and France-Italy the countries that contributed the most for each said continent, respectively. Most of the isolated LAB belong to the genera Enterococcus (35%), Lactobacillus (30%), Lactococcus (14%), and Pediococcus (10%), coming from soft (64%), hard (27%), and semi-hard (9%) cheeses, predominantly. Also, scholars focused mainly on the food biopreservation (81%) and pharmaceutical field (18%) potential applications.

Idiopathic left fascicular ventricular tachycardia in children and adolescents.

BACKGROUND: Idiopathic ventricular tachycardia (VT) in children with structurally normal hearts is generally unrelated to the risk of sudden arrhythmic death. Still, it may be associated with deterioration in the quality of life. VT involving the fascicular conduction system is the most typical form of idiopathic left VT. In this retrospective study, we describe the experience of the clinical presentation, catheter ablation, and long-term follow-up of left fascicular VT in children. METHODS: An electrophysiological study was performed on consecutive children at a single tertiary center. Clinical fascicular left VT was induced by programmed stimulation, and catheter ablation was guided searching for Purkinje potentials. RESULTS: We included 18 patients (0.8 patients/year): 14 (77.8%) males and four females. The mean age of the first VT episode was 8.5 ± 5 years. Intravenous verapamil administration was effective for paroxysmal fascicular VT but not for prevention of recurrences. The mean age at the time of catheter ablation was 11.1 ± 3.8 years (8 months-16 years). The mean weight was 36.8 ± 16.4 kg (8.7-58 kg). A 100% success rate was observed with catheter ablation after repeated procedures without major complications. Mean follow-up was 2.0 ± 1.2 years (1.0-4.0 years, median 1.5), with permanent success in all patients and no antiarrhythmic drug administration. CONCLUSIONS: Fascicular VT has an adverse clinical course in children. In most cases, this condition is drug refractory. Catheter ablation is successful and safe treatment and should represent the first-line approach in symptomatic children.

INTRODUCCIÓN: La taquicardia ventricular (TV) idiopática en niños con corazón estructuralmente normal generalmente no se relaciona con el riesgo de muerte súbita arrítmica, pero puede asociarse con deterioro de la calidad de vida. La TV que involucra el sistema de conducción fascicular es la forma más común de TV izquierda idiopática. En este estudio retrospectivo se describe la experiencia de presentación clínica, ablación con catéter y seguimiento a largo plazo de TV fascicular en niños. MÉTODOS: Se llevó a cabo un estudio electrofisiológico en niños consecutivos en un centro terciario. La TV fascicular clínica se indujo mediante la estimulación programada y la ablación con catéter fue guiada buscando el registro de potenciales de Purkinje. RESULTADOS: Se incluyeron 18 pacientes (0.8 pacientes/año): 14 (77.8%) de sexo masculino y cuatro de sexo femenino. La media de edad a la cual ocurrió el primer episodio fue de 8.5 ± 5 años. La administración intravenosa de verapamilo fue eficaz para la TV fascicular paroxística, pero no para prevención de recurrencias. La media de edad de la ablación con catéter fue de 11.1 ± 3.8 años (8 meses-16 años). La media del peso fue 36.8 ± 16.4 kg (8.7-58 kg). Se observó el 100% de éxito con la ablación con catéter después de procedimientos repetidos sin complicaciones mayores. La media de seguimiento fue de 2.0 ± 1.2 años (1.0-4.0, mediana de 1.5 años) con éxito permanente en todos los pacientes y sin administración de fármacos antiarrítmicos. CONCLUSIONES: En niños, el curso clínico de la TV fascicular es adverso. Además, en la mayoría de los casos, esta condición es refractaria a fármacos. La ablación con catéter resulta exitosa y segura y debe representar el abordaje de primera línea en niños sintomáticos.

Randomized pilot trial of cognitive-behavioral therapy and acceptance-based behavioral therapy in the treatment of Spanish-speaking Latino primary care patients with generalized anxiety disorder.

The evidence base supporting the usefulness of traditional cognitive-behavioral therapy (CBT) and newer acceptance-based CBT treatments for generalized anxiety disorder (GAD) has grown over the past decades. GAD is prevalent among several Latino subgroups, particularly Puerto Ricans. However, there remains uncertainty regarding the appropriateness of these interventions for Spanish-speaking Latinos since they have been routinely excluded in both efficacy and effectiveness studies. As an initial step to bridge this gap, this pilot study examined the potential efficacy of two CBT interventions for GAD, traditional CBT and acceptance-based behavioral therapy (ABBT), in a sample of Spanish-speaking Latinos. Ninety primary care patients with GAD were randomly assigned to receive CBT (n=30), ABBT (n=30), or treatment as usual (TAU) (n=30). Excessive worry, the core feature of GAD, was assessed with the Penn State Worry Questionnaire (PSWQ), which is considered the gold standard measure of GAD-related worry. At follow-up, PSWQ scores for participants in the CBT and ABBT groups were statistically lower than those of the TAU group and statistically comparable to each other. CBT and ABBT reduced worry level to a greater degree than usual care by follow-up. Our findings provide preliminary, yet crucial data, which support the potential of both interventions targeting GAD symptoms among Spanish-speaking Latino primary care patients.

A review of extracellular polysaccharides from extreme niches: An emerging natural source for the biotechnology. From the adverse to diverse!

Every year, new organisms that survive and colonize adverse environments are discovered and isolated. Those organisms, called extremophiles, are distributed throughout the world, both in aquatic and terrestrial environments, such as sulfurous marsh waters, hydrothermal springs, deep waters, volcanos, terrestrial hot springs, marine saltern, salt lakes, among others. According to the ecosystem inhabiting, extremophiles are categorized as thermophiles, psychrophiles, halophiles, acidophiles, alkalophilic, piezophiles, saccharophiles, metallophiles and polyextremophiles. They have developed chemical adaptation strategies that allow them to maintain their cellular integrity, altering physiology or improving repair capabilities; one of them is the biosynthesis of extracellular polysaccharides (EPS), which constitute a slime and hydrated matrix that keep the cells embedded, protecting from environmental stress (desiccation, salinity, temperature, radiation). EPS have gained interest; they are explored by their unique properties such as structural complexity, biodegradability, biological activities, and biocompatibility. Here, we present a review concerning the biosynthesis, characterization, and potential EPS applications produced by extremophile microorganisms, namely, thermophiles, halophiles, and psychrophiles. A bibliometric analysis was conducted, considering research articles published within the last two decades. Besides, an overview of the culture conditions used for extremophiles, the main properties and multiple potential applications of their EPS is also presented.

Physicochemical characterization and emulsifying properties of a novel exopolysaccharide produced by haloarchaeon Haloferax mucosum.

The physicochemical characterization and emulsifying functional properties of a novel exopolysaccharide (EPS) produced by haloarchaea Haloferax mucosum (DSM 27191) were investigated. This biopolymer has a high molecular weight of 152 kDa and important protein content of 10%. Different culture media compositions were investigated taking the ATCC 2185 medium as a base and supplementing with varying concentrations of yeast extract and glucose or sucrose as carbon sources to produce the EPS in a liquid medium. The highest EPS production (7.15 ±â€¯0.44 g/L) was obtained at 96 h. EPS aqueous dispersions showed a non-Newtonian rheological behavior which was well fitted to the Cross equation. The EPS (at 0.32% w/w) was capable of stabilizing water-in-oil emulsions with different nonpolar solvents, including n-hexane, kerosene, chloroform, castor oil and mineral oil. EPS retained its emulsifying activity after to be incubated for one hour in a wide range of temperatures (25, 40, 70 and 100 °C), pH (4, 6.5, 7 and 12) and NaCl concentrations (0, 2.0 and 4.0 M). The viscoelastic behavior and stability of hexane-in-water emulsion were examined through oscillatory shear measurements.

Anticoagulation Therapy by Age and Embolic Risk for Nonvalvular Atrial Fibrillation in Mexico, an Upper-Middle-Income Country: The CARMEN-AF Registry.

Background: Documenting the patterns of oral anticoagulation therapy (OAT) is essential to prevent thromboembolic complications of nonvalvular atrial fibrillation (NVAF). Objective: To report the patterns of OAT according to age and thromboembolic risk in patients included in CARMEN-AF, a nationwide registry of NVAF in Mexico, an upper middle-income country. Material and methods: There were 1,423 consecutive patients ≥18 years old and with at least one thromboembolic risk factor enrolled in the CARMEN-AF Registry at their regular clinical visit during a three-year period. They were analyzed according to 1) age, 2) AF type, and 3) CHA2DS2-VASc score. Results: Overall, 16.4% of patients did not receive antithrombotic treatment, 19.4% received antiplatelet drugs (APD), 29.2% vitamin K antagonists (VKA), and 34.6% direct oral anticoagulants (DOAC). With increasing age, the proportion of subjects treated with VKA decreased significantly from 36.2% in subjects <65 years to 22.5% in those ≥75 years old (P <0.0001). Concomitantly, an increase in both APD and no antithrombotic treatment was observed with increasing age. DOAC were prescribed equally among all age groups (34.2% in <65, 36.0% in 65-74, and 33.9% in ≥75). According to the type of AF, VKA use was more common in patients with permanent AF (32.7%). A lower use of DOAC was observed in high thromboembolic risk subjects (33.6% in CHA2DS2-VASc ≥2) compared with the moderate risk group (41% in CHA2DS2-VASc = 1). Conclusions: VKA use for NVAF in Mexico decreased in relation to increasing age. The proportion of DOAC therapy was the same in all age groups. Nevertheless, elderly patients with high thromboembolic risk received a suboptimal thromboprophylaxis. These data could help to improve gaps in the implementation of global guidelines. Clinical trial registration: http://www.clinicaltrials.gov. Unique identifier: NCT02334852. Highlights: CARMEN-AF is a nationwide multi-centric registry seeking to bridge the data gap on anticoagulation therapy for NVAF in Mexico.Elderly patients are more prone to receive suboptimal OAT for NVAF.DOAC were less frequently used in high thromboembolic risk patients (CHA2DS2-VASc ≥2).

Coumel tachycardia in children / Taquicardia de Coumel en niños

Abstract Background: Coumel tachycardia is an infrequent form of supraventricular tachycardia (SVT) that usually occurs in infants and children. It is a tachycardia mediated by an accessory pathway with retrograde slow conduction that explains the classic ECG pattern with long RP' interval and negative P waves in leads II, III, and aVF. In this study, we describe the clinical course and management of Coumel tachycardia in children. Case report: We conducted a retrospective review of five consecutive pediatric patients, mean age 11 ± 3 years (range 6 to 14). The first episode of SVT was at a mean age of 10.4 ± 4.8 years (range 2 to 14) with a mean evolution of 7.4 ± 9.4 months (range 1 to 24). Pharmacological therapy was unsuccessful despite the combination of antiarrhythmic drugs. The tachycardia was incessant with a density > 85% by 24-hour Holter monitoring; one patient developed tachycardia-induced cardiomyopathy. All children underwent successful radiofrequency catheter ablation, mean 5 ± 3 applications (range 1 to 8) with a single session and with no complications. After a mean follow-up of 24 ± 16 months, all patients were asymptomatic and recurrence-free without antiarrhythmic treatment. Conclusions: Coumel tachycardia is clinically persistent and usually refractory to antiarrhythmic treatment with substantial risk of tachycardia-mediated cardiomyopathy. Catheter ablation is effective and safe in children; thus, it should be indicated promptly and based on individual selection.

Resumen Introducción: La taquicardia de Coumel es una forma poco frecuente de taquicardia supraventricular que suele presentarse en lactantes. Es una taquicardia mediada por una vía accesoria de conducción lenta retrógrada que explica el patrón ECG clásico con intervalo RP' largo y ondas P negativas en las derivaciones II, III y aVF. En este trabajo se describe el curso clínico y el manejo de la taquicardia de Coumel en niños. Caso clínico: Se llevó a cabo una revisión retrospectiva de cinco pacientes pediátricos consecutivos, con una media de edad de 11 ± 3 años (intervalos 6 a 14). El primer episodio de taquicardia 10.4 ± 4.8 años con evolución de 7.4 ± 9.4 meses. El tratamiento farmacológico fue ineficaz a pesar de la combinación de antiarrítmicos. La taquicardia era incesante con una densidad > 85% por Holter-24h; un paciente desarrolló miocardiopatía inducida por taquicardia. Todos los niños fueron sometidos a ablación con catéter y radiofrecuencia con éxito, y un promedio de 5 ± 3 aplicaciones en una sola sesión y sin complicaciones. Después de un seguimiento de 24 ± 16 meses, todos los pacientes fueron asintomáticos y libres de recurrencia sin tratamiento antiarrítmico. Conclusiones: La taquicardia de Coumel es clínicamente persistente y generalmente refractaria al tratamiento antiarrítmico con un riesgo sustancial de miocardiopatía mediada por taquicardia. La ablación con catéter es eficaz y segura en niños, por lo que debe indicarse de forma temprana y en lactantes de una selección individual.

Partial characterization of chayotextle starch-based films added with ascorbic acid encapsulated in resistant starch.

Chayotextle starch was modified by subjecting it to a dual treatment with acid and heating-cooling cycles. This caused a decrease in the content of amylose, which showed values of 30.22%, 4.80%, 3.27% and 3.57% for native chayotextle starch (NCS), starch modified by acid hydrolysis (CMS), and CMS with one (CMS1AC) and three autoclave cycles (CMS3AC), respectively. The percentage of crystallinity showed an increase of 36.9%-62% for NCS and CMS3AC. The highest content of resistant starch (RS) was observed in CMS3AC (37.05%). The microcapsules were made with CMS3AC due to its higher RS content; the total content of ascorbic acid of the microcapsules was 82.3%. The addition of different concentrations of CMS3AC microcapsules (0%, 2.5%, 6.255% and 12.5%) to chayotextle starch-based films (CSF) increased their tensile strength and elastic modulus. The content of ascorbic acid and RS in CSF was ranged from 0% to 59.4% and from 4.84% to 37.05% in the control film and in the film mixed with CMS3AC microcapsules, respectively. Water vapor permeability (WVP) values decreased with increasing concentrations of microcapsules in the films. Microscopy observations showed that higher concentrations of microcapsules caused agglomerations due their poor distribution in the matrix of the films.

Idiopathic left fascicular ventricular tachycardia in children and adolescents / Taquicardia ventricular fascicular izquierda idiopática en niños y adolescentes

Abstract Background: Idiopathic ventricular tachycardia (VT) in children with structurally normal hearts is generally unrelated to the risk of sudden arrhythmic death. Still, it may be associated with deterioration in the quality of life. VT involving the fascicular conduction system is the most typical form of idiopathic left VT. In this retrospective study, we describe the experience of the clinical presentation, catheter ablation, and long-term follow-up of left fascicular VT in children. Methods: An electrophysiological study was performed on consecutive children at a single tertiary center. Clinical fascicular left VT was induced by programmed stimulation, and catheter ablation was guided searching for Purkinje potentials. Results: We included 18 patients (0.8 patients/year): 14 (77.8%) males and four females. The mean age of the first VT episode was 8.5 ± 5 years. Intravenous verapamil administration was effective for paroxysmal fascicular VT but not for prevention of recurrences. The mean age at the time of catheter ablation was 11.1 ± 3.8 years (8 months-16 years). The mean weight was 36.8 ± 16.4 kg (8.7-58 kg). A 100% success rate was observed with catheter ablation after repeated procedures without major complications. Mean follow-up was 2.0 ± 1.2 years (1.0-4.0 years, median 1.5), with permanent success in all patients and no antiarrhythmic drug administration. Conclusions: Fascicular VT has an adverse clinical course in children. In most cases, this condition is drug refractory. Catheter ablation is successful and safe treatment and should represent the first-line approach in symptomatic children.

Resumen Introducción: La taquicardia ventricular (TV) idiopática en niños con corazón estructuralmente normal generalmente no se relaciona con el riesgo de muerte súbita arrítmica, pero puede asociarse con deterioro de la calidad de vida. La TV que involucra el sistema de conducción fascicular es la forma más común de TV izquierda idiopática. En este estudio retrospectivo se describe la experiencia de presentación clínica, ablación con catéter y seguimiento a largo plazo de TV fascicular en niños. Métodos: Se llevó a cabo un estudio electrofisiológico en niños consecutivos en un centro terciario. La TV fascicular clínica se indujo mediante la estimulación programada y la ablación con catéter fue guiada buscando el registro de potenciales de Purkinje. Resultados: Se incluyeron 18 pacientes (0.8 pacientes/año): 14 (77.8%) de sexo masculino y cuatro de sexo femenino. La media de edad a la cual ocurrió el primer episodio fue de 8.5 ± 5 años. La administración intravenosa de verapamilo fue eficaz para la TV fascicular paroxística, pero no para prevención de recurrencias. La media de edad de la ablación con catéter fue de 11.1 ± 3.8 años (8 meses-16 años). La media del peso fue 36.8 ± 16.4 kg (8.7-58 kg). Se observó el 100% de éxito con la ablación con catéter después de procedimientos repetidos sin complicaciones mayores. La media de seguimiento fue de 2.0 ± 1.2 años (1.0-4.0, mediana de 1.5 años) con éxito permanente en todos los pacientes y sin administración de fármacos antiarrítmicos. Conclusiones: En niños, el curso clínico de la TV fascicular es adverso. Además, en la mayoría de los casos, esta condición es refractaria a fármacos. La ablación con catéter resulta exitosa y segura y debe representar el abordaje de primera línea en niños sintomáticos.

Monoxenic liquid culture of the entomopathogenic nematode Steinernema carpocapsae using a culture medium containing whey kinetics and modeling.

The submerged culture of the entomopathogenic nematode Steinernema carpocapsae and its symbiotic bacterium, Xenorhabdus nematophila, was carried out in orbitally agitated bottles using a culture medium containing whey (in grams per litre: 500 whey, 20 yeast extract, 10 dried egg yolk-food grade, 3 sodium chloride, 37 corn oil-food grade). Maximum total viable nematode concentrations of 198,333ml(-1) were achieved within fermentations of 24 days with 64% of the nematode population within the infective juvenile stage (IJ) (126,666ml(-1)) at the end. The kinetics of the bioprocess was well modelled using the four-parameter Sigmoidal model and the corresponding maximum specific rates of nematode production (0.47 day(-1)), carbohydrates consumption (0.0008g(carbohydrates)g(nematodes)(-1)day(-1)) and nitrogen consumption (4.44g(nitrogen)g(nematodes)(-1)day(-1)) are first proposed. Besides, X. nematophila appears to have the capacity of lactose hydrolysis.

The genome, transcriptome, and proteome of the nematode Steinernema carpocapsae: evolutionary signatures of a pathogenic lifestyle.

The entomopathogenic nematode Steinernema carpocapsae has been widely used for the biological control of insect pests. It shares a symbiotic relationship with the bacterium Xenorhabdus nematophila, and is emerging as a genetic model to study symbiosis and pathogenesis. We obtained a high-quality draft of the nematode's genome comprising 84,613,633 bp in 347 scaffolds, with an N50 of 1.24 Mb. To improve annotation, we sequenced both short and long RNA and conducted shotgun proteomic analyses. S. carpocapsae shares orthologous genes with other parasitic nematodes that are absent in the free-living nematode C. elegans, it has ncRNA families that are enriched in parasites, and expresses proteins putatively associated with parasitism and pathogenesis, suggesting an active role for the nematode during the pathogenic process. Host and parasites might engage in a co-evolutionary arms-race dynamic with genes participating in their interaction showing signatures of positive selection. Our analyses indicate that the consequence of this arms race is better characterized by positive selection altering specific functions instead of just increasing the number of positively selected genes, adding a new perspective to these co-evolutionary theories. We identified a protein, ATAD-3, that suggests a relevant role for mitochondrial function in the evolution and mechanisms of nematode parasitism.