Continuous polyhydroxybutyrate production from biogas in an innovative two-stage bioreactor configuration.

Biogas biorefineries have opened up new horizons beyond heat and electricity production in the anaerobic digestion sector. Added-value products such as polyhydroxyalkanoates (PHAs), which are environmentally benign and potential candidates to replace conventional plastics, can be generated from biogas. This work investigated the potential of an innovative two-stage growth-accumulation system for the continuous production of biogas-based polyhydroxybutyrate (PHB) using Methylocystis hirsuta CSC1 as cell factory. The system comprised two turbulent bioreactors in series to enhance methane and oxygen mass transfer: a continuous stirred tank reactor (CSTR) and a bubble column bioreactor (BCB) with internal gas recirculation. The CSTR was devoted to methanotrophic growth under nitrogen balanced growth conditions and the BCB targeted PHB production under nitrogen limiting conditions. Two different operational approaches under different nitrogen loading rates and dilution rates were investigated. A balanced nitrogen loading rate along with a dilution rate (D) of 0.3 day-1 resulted in the most stable operating conditions and a PHB productivity of ~53 g PHB m-3 day-1 . However, higher PHB productivities (~127 g PHB m-3 day-1 ) were achieved using nitrogen excess at a D = 0.2 day-1 . Overall, the high PHB contents (up to 48% w/w) obtained in the CSTR under theoretically nutrient balanced conditions and the poor process stability challenged the hypothetical advantages conferred by multistage vs single-stage process configurations for long-term PHB production.

Electroforesis de isoenzimas de fosfatasa alcalina: utilidad diagnóstica en pacientes con enfermedad de células falciformes / Alkaline phosphatase isoenzyme electrophoresis: diagnostic utility in patients with sickle cell disease

Introducción: Las fosfatasas alcalinas (FAL) humanas son indicadores enzimáticos de daño de órganos. Las complicaciones de la drepanocitosis incluyen lesión de órganos debido a la reperfusión, la vasculopatía proliferativa y la anemia hemolítica. Objetivo: Demostrar la utilidad de la determinación de la actividad enzimática de la FAL y la movilidad electroforética de las isoenzimas séricas de FAL en pacientes con drepanocitosis en estado basal y durante las crisis. Métodos: Estudio descriptivo, longitudinal, prospectivo en 85 individuos adultos, 25 controles sanos y 60 pacientes, entre enero y diciembre/2018. Variables estudiadas: genotipos (SS/Sβo, SC/Sβ+), edad, sexo, actividad de FAL e isoenzimas por electroforesis en gel de agarosa con y sin lectina: hepática 1 (H1) y (H2); placenta 1(P1), ósea, intestinales 1, 2, 3 (I1.2.3) en estado basal y crisis. Resultados: La actividad de la FAL fue significativamente mayor en los pacientes que en los controles. Hubo diferencias significativas en la actividad de la FAL y de la fracción H1+P1/1 de pacientes en estado basal en relación con el grupo control. La actividad de la enzima y las isoenzimas no mostró diferencias significativas entre los genotipos. Igual comportamiento se observó en la actividad de las enzimas e isoenzimas durante las crisis vasoclusivas dolorosas y hepáticas. Se encontraron diferencias significativas en la actividad de la fracción hepática H1+P1/1 entre los grupos de 20-29 y 40-49 años Conclusiones: La determinación de la FAL en los pacientes con drepanocitosis es útil y permite establecer un perfil isoenzimático personalizado, con importancia pronóstica como un marcador biológico de alarma(AU)

Introduction: Human alkaline phosphatases (ALP) are enzymatic indicators of organ damage. Complications of sickle cell disease include injury to organs due to reperfusion injury, proliferative vascular disease, and hemolytic anemia. Objective: To demonstrate the usefulness of determing ALP activity and the electrophoretic mobility of the serum ALP isoenzymes in patients with sickle cell disease at base line and during the crises. Methods: A descriptive, longitudinal, prospective study was carried out in 85 adult individuals, 25 healthy controls and 60 patients, between January and December/2018. Studied variables: genotypes (SS/SβO, SC/Sβ+), age, sex, ALP activity and isoenzymes by agarose gel electrophoresis with and without lectin: hepatic 1 (H1) and (H2); placenta 1 (P1), bone, intestinal 1, 2, 3 (I1.2.3) in basal state and crisis. Results: ALP activity was significantly higher in patients than in controls. Significant differences were found in the activity of the ALP and fraction H1+P1/1 of patients in basal state in relation to the control group. The activity of the enzyme and the isoenzymes showed no significant differences between genotypes. The same behavior was observed in the activity of enzymes and isoenzymes during painful and liver vasooclusive crises. Significant differences were found in the activity of the liver fraction H1+P1/1 between the groups of 20-29 and 40-49 years. Conclusions: The determination of the ALP in patients with sickle cell disease is useful and allows to establish a personalized isoenzimatic profile, with prognostic importance as a biological alarm marker(AU)

Importancia clínica del diagnóstico de la metahemoglobinemia / Clinical importance of the diagnosis of methemoglobinemia

Introducción: La metahemoglobina es una forma de hemoglobina en la que el grupo hemo, usualmente en forma ferrosa, es oxidado a forma férrica, lo que afecta el transporte de oxígeno. El incremento por encima de los valores de referencia se denomina metahemoglobinemia. Objetivo: Actualizar conceptos como prevención, manifestaciones clínicas, diagnóstico de laboratorio y tratamiento de elección de esta enfermedad, con la información disponible de la última década. Métodos: Se realizó una revisión de la literatura en inglés y español, a través del sitio web PubMed, el motor de búsqueda Google académico y Scielo, de artículos publicados en los últimos 10 años. Los términos de búsqueda usados incluyeron metahemoglobinemia, déficit de citocromo b5 reductasa, cianosis y cooximetría. Análisis y síntesis de la información: La metahemoglobinemia se puede clasificar en congénita y adquirida, esta última es la más frecuente. Es importante el diagnóstico de esta enfermedad que aunque es un padecimiento poco común, puede cursar con complicaciones graves e incluso la muerte. Puede ser evitable con diagnóstico temprano y tratamiento oportuno para reducir las complicaciones asociadas a este cuadro. Conclusiones: El diagnóstico y el tratamiento, profiláctico y terapéutico de la metahemoglobinemia en su etapa aguda o de mantenimiento, requieren la adecuada actualización del profesional de la salud(AU)

Introduction: Methemoglobin is a form of hemoglobin in which the heme group, usually in the ferrous form, is oxidized to the ferric form, which affects oxygen transport. The increase above the reference values ​​is called methemoglobinemia. Objective: To update concepts such as prevention, clinical manifestations, laboratory diagnosis and treatment of choice for this disease, with the information available from the last decade. Methods: A review of the literature in English and Spanish was carried out, through the PubMed website, the academic Google search engine and Scielo database, of articles published in the last 10 years. Search terms used included methemoglobinemia, cytochrome b5 reductase deficiency, cyanosis, and co-oximetry. Analysis and synthesis of information: Methemoglobinemia can be classified into congenital and acquired, the latter being the most common. It is important to diagnose this disease, which, although it is a rare condition, can cause serious complications, and even death, which are avoidable with early diagnosis and timely treatment that reduce the complications associated with this condition. Conclusions: The diagnosis and treatment, prophylactic and therapeutic, of methemoglobinemia, in its acute or maintenance stage, require adequate updating of the health professional(AU)

Biogas bioconversion into poly(3-hydroxybutyrate) by a mixed microbial culture in a novel Taylor flow bioreactor.

Biogas-based biopolymer production represents an alternative biogas valorization route with potential to cut down plastic pollution and greenhouse gas emissions. This study investigated for the first time the continuous bioconversion of methane, contained in biogas, into poly(3-hydroxybutyrate) (PHB) by a mixed methanotrophic culture using an innovative high mass-transfer Taylor flow bioreactor. Following a hydrodynamic flow regime mapping, the influence of the gas residence time and the internal gas recirculation on CH4 abatement was assessed under non nutrient limiting conditions. Under optimal operational conditions (gas residence time of 60 min and internal gas recycling ratio of 17), the bioreactor was able to support a CH4 removal efficiency of 63.3%, a robust CH4 elimination capacity (17.2 g-CH4 m-3h-1) and a stable biomass concentration (1.0 g L-1). The simultaneous CH4 abatement and PHB synthesis was investigated under 24-h:24-h nitrogen feast/famine continuous operation. The cyclic nitrogen starvation and the Taylor flow imposed in the bioreactor resulted in a relatively constant biomass concentration of 0.6 g L-1 with PHB contents ranging from 11 to 32% w w-1 (on a dry weight basis), entailing an average PHB productivity of 5.9 g-PHB m-3 d-1 with an associated PHB yield of 19.8 mg-PHB g-CH4-1. Finally, the molecular analysis of the microbial population structure indicated that type II methanotrophs outcompeted non-PHB accumulating type I methanotrophs, with a heterotrophic-methanotrophic consortium enriched in Methylocystis, Hyphomicrobium, Rubinisphaeraceae SH PL14 and Pseudonocardia.

Systematic comparison of a biotrickling filter and a conventional filter for the removal of a mixture of hydrophobic VOCs by Candida subhashii.

This work systematically compared the potential of a conventional fungal biofilter (BF) and a fungal biotrickling filter (BTF) for the abatement of a mixture of hydrophobic volatile organic compounds (VOCs). Candida subhashii was herein used for the first time, to the best of the author's knowledge, to remove n-hexane, trichloroethylene, toluene and α-pinene under aerobic conditions. C. subhashii immobilized on polyurethane foam supported steady state removal efficiencies of n-hexane, trichloroethylene, toluene and α-pinene of 25.4 ± 0.9%, 20.5 ± 1.0%, 19.6 ± 1.5% and 25.6 ± 2.8% in the BF, and 35.7 ± 0.9%, 24.0 ± 1.6%, 44.0 ± 1.7% and 26.2 ± 1.8% in the BTF, respectively, at relatively short gas residence times (30 s). The ability of C. subhashii to biodegrade n-hexane, TCE, toluene and α-pinene was confirmed in a batch test conducted in serum bottles, where a biodegradation pattern (toluene ≈ n-hexane > α-pinene > trichloroethylene) comparable to that recorded in the BF and BTF was recorded.

Optimization of nitrogen feeding strategies for improving polyhydroxybutyrate production from biogas by Methylocystis parvus str. OBBP in a stirred tank reactor.

The design of efficient cultivation strategies to produce bioplastics from biogas is crucial for the implementation of this biorefinery process. In this work, biogas-based polyhydroxybutyrate (PHB) production and CH4 biodegradation performance was investigated for the first time in a stirred tank bioreactor inoculated with Methylocystis parvus str. OBBP. Decreasing nitrogen loading rates in continuous mode and alternating feast:famine regimes of 24 h-cycles, and alternating feast:famine regimes of 24 h:24 h and 24 h:48 h were tested. Continuous N feeding did not support an effective PHB production despite the occurrence of nitrogen limiting conditions. Feast-famine cycles of 24 h:24 h (with 50% stoichiometric nitrogen supply) supported the maximum PHB production (20 g-PHB m-3 d-1) without compromising the CH4-elimination capacity (25 g m-3 h-1) of the system. Feast:famine ratios ≤1:2 entailed the deterioration of process performance at stoichiometric nitrogen inputs ≤60%.

Production of (R)-3-hydroxybutyric acid from methane by in vivo depolymerization of polyhydroxybutyrate in Methylocystis parvus OBBP.

Methylocystis parvus OBBP accumulates polyhydroxybutyrate (PHB) using methane as the sole carbon and energy source. In this work, the feasibility of producing (R)-3-hydroxybutyric acid (R3HBA) via intracellularly accumulated PHB through depolymerization (in-vivo) was investigated. Results showed that a PHB to R3HBA conversion of 77.2 ± 0.9% (R3HBA titer of 0.153 ± 0.002 g L-1) can be attained in a mineral medium containing 1 g L-1 KNO3 at 30 °C with shaking at 200 rpm and a constant pH of 11 for 72 h. Nitrogen deprivation and neutral or acidic pHs strongly reduced the excreted R3HBA concentration. Reduced oxygen availability negatively affected the R3HBA yield, which decreased to 73.6 ± 4.9% (titer of 0.139 ± 0.01 g L-1) under microaerobic conditions. Likewise, the presence of increasing concentrations of R3HBA in the medium before the onset of PHB depolymerization reduced the initial R3HBA release rate and R3HBA yield.

Clasificación y métodos de diagnóstico de las membranopatías / Classification and diagnostic methods of membranopathies

Introducción: Las membranopatías son anemias hemolíticas hereditarias debidas a anomalías cualitativas o deficiencias cuantitativas de las proteínas del citoesqueleto del glóbulo rojo. Objetivo: Actualizar el diagnóstico de las membranopatías con la inclusión de las últimas recomendaciones del comité de grupos de expertos a nivel nacional e internacional. Métodos: Se realizó una revisión de la literatura en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google académico, de artículos publicados en los últimos cinco años. Análisis y síntesis de la información: Las enfermedades de mayor interés clínico son: la esferocitosis, la eliptocitosis y la estomatocitosis hereditaria. Estas en general se heredan con carácter autosómico dominante pero existen formas que se transmiten con carácter recesivo, sin descartar posible mutación de novo. Para su diagnóstico se utilizan pruebas que incluyen el estudio de la morfología de los glóbulos rojos, la fragilidad osmótica, la lisis de glicerol acidificado, la criohemólisis hipertónica, la prueba de unión a la eosina-5'-maleimida por citometría de flujo, la electroforesis en gel de poliacrilamida con dodecilsulfato sódico y la ectacitometría. Conclusiones: Las membranopatías pueden sospecharse de manera preliminar teniendo en cuenta algunas alteraciones de la morfología eritrocitaria, aunque el diagnóstico se basa en estudios familiares y otros de carácter confirmatorio de la enfermedad, como los estudios moleculares. Los profesionales de la salud que atienden a pacientes jóvenes con anemia deben considerar la posibilidad de una anemia hemolítica por trastornos de la membrana eritrocitaria(AU)

ABSTRACT Introduction: Membranopathies are inherited hemolytic anemias due to qualitative abnormalities or quantitative deficiencies of red blood cell cytoskeletal proteins. Objective: to update the diagnosis of membranopathies with the inclusion of the latest recommendations from the committee of expert groups at the national and international level. Methods: A review of the literature in English and Spanish was carried out, through the PubMed website and the academic search engine Google, in articles published in the last five years. Analysis and synthesis of information: The diseases of greatest clinical interest are: spherocytocis, elliptocytosis and hereditary stomatocytosis. These are generally inherited with an autosomal dominant character but there are forms that are transmitted recessively, without ruling out a possible de novo mutation. For its diagnosis, tests are used that include the study of red blood cell morphology, osmotic fragility, acidified glycerol lysis, hypertonic cryohemolysis, eosin-5'-maleimide binding test by flow cytometry, sodium dodecyl sulfate polyacrylamide gel electrophoresis and ectacytometry. Conclusions: Membranopathies can be preliminarily suspected taking into account some alterations in erythrocyte morphology, although the diagnosis is based on family studies and others confirming the disease, such as molecular studies. Healthcare professionals caring for young patients with anemia should consider the possibility of hemolytic anemia due to red cell membrane disorders(AU)

Trastornos metabólicos urinarios en pacientes urolitiásicos con enfermedad renal poliquística y sin ella / Urinary metabolic disorders in urolithiasis patients with and without polycystic kidney disease

Introducción: La urolitiasis se ha incrementado en las últimas décadas. La enfermedad renal poliquística autosómica dominante (ERPAD), enfermedad renal hereditaria más frecuente, ocupa un lugar preponderante. Objetivos: Identificar la frecuencia de presentación de los trastornos metabólicos urinarios en pacientes litiásicos cubanos con ERPAD y sin ella Métodos: Estudio descriptivo, transversal. Fueron estudiados 579 pacientes adultos sin ERPAD, seleccionados por muestreo simple aleatorio y los 21 pacientes con ERPAD, del total de pacientes con litiasis urinaria que se realizó estudio metabólico renal en el Laboratorio de Fisiopatología Renal del Instituto de Nefrología, en el periodo 2010-2015. Los datos fueron tomados de la historia clínica y del informe de estudio metabólico renal. La información se procesó de forma automatizada (SPSS 22.0). Se utilizó el promedio, desviación estándar, análisis de distribución de frecuencias y el test de homogeneidad. Resultados: En los pacientes con ERPAD predominó el sexo femenino (57,1 por ciento), mientras que en los pacientes sin ERPAD, el masculino (63,4 por ciento). Los trastornos más frecuentes en la población no poliquística fueron hipercalciuria (45,3 por ciento) e hipofosfatemia (17,1 por ciento). En los poliquísticos, aclaramiento aumentado de ácido úrico (38,1 por ciento) e hipercalciuria (23,8 por ciento). Se encontraron diferencias estadísticamente significativas para aumento del aclaramiento de ácido úrico (p = 0,01) e hiperfosfatemia (p = 0,04). Conclusiones: Los principales trastornos metabólicos de los pacientes litiásicos, tanto poliquísticos como no poliquísticos, son el aclaramiento de ácido úrico aumentado, hipercalciuria, hiperuricosuria e hipofosfatemia, aunque el orden de presentación es diferente. El aclaramiento de ácido úrico aumentado y la hiperfosfatemia se presentan con mayor frecuencia en los pacientes litiásicos poliquísticos(AU)

Introduction: Urolithiasis has increased in recent decades. Autosomal dominant polycystic kidney disease (ADPKD), the most common of all hereditary kidney diseases, occupies a predominant position in terms of incidence. Objectives: Identify the frequency of occurrence of urinary metabolic disorders in Cuban urolithiasis patients with and without ADPKD. Methods: A descriptive cross-sectional study was conducted of 579 adult patients without ADPKD selected by simple random sampling, and 21 patients with ADPKD, from the total urolithiasis patients undergoing renal metabolic evaluation at the Renal Physiopathology Laboratory of the Institute of Nephrology in the period 2010-2015. Data were obtained from medical records and reports of renal metabolic studies. Information was processed with the statistical software SPSS version 22.0. Average and standard deviation were estimated and use was made of frequency distribution analysis and homogeneity testing. Results: A predominance was found of female sex among patients with ADPKD (57.1 percent) and male sex among patients without ADPKD (63.4 percent). The most common disorders were hypercalciuria (45.3 percent) and hypophosphatemia (17.1 percent) in the non-polycystic population, and increased uric acid clearance (38.1 percent) and hypercalciuria (23.8 percent) in polycystic patients. Statistically significant differences were found in uric acid clearance increase (p = 0.01) and hyperphosphatemia (p = 0.04). Conclusions: The main metabolic disorders of lithiasis patients, polycystic as well as non-polycystic, are increased uric acid clearance, hypercalciuria, hyperuricosuria and hypophosphatemia, with a varying order of presentation. Increased uric acid clearance and hyperphosphatemia are more common in polycystic lithiasis patients(AU)

Software educativo de matemática para estudiantes de Vigilancia y Lucha Antivectorial / Mathematics educational software for Surveillance and Vector Control students

RESUMEN Introducción: el software educativo juega un rol importante en el proceso enseñanza aprendizaje en la Educación Médica Superior en Cuba. Es una valiosa herramienta que contribuirá de manera significativa al desarrollo del auto aprendizaje de la matemática. Objetivo: proponer un software educativo como recurso didáctico para el desarrollo del proceso de enseñanza aprendizaje de la asignatura matemática en la carrera de Vigilancia y Lucha Antivectorial. Métodos: se realizó un estudio de desarrollo tecnológico en el área de recursos para el aprendizaje en la Filial de Ciencias Médicas ¨Lidia Doce Sánchez¨ de Mayarí, en el período de enero del 2018 a junio del 2019. El universo estuvo constituido por 39 estudiantes de las carreras de Tecnología de la Salud y 18 profesores que les imparten docencia a estos estudiantes. La muestra fue de 27 estudiantes y cinco profesores que imparten la asignatura matemática, escogidos de forma intencional, se utilizaron métodos teóricos y dentro de los empíricos, el cuestionario, la técnica de lluvia de ideas y la observación. Se utilizó escala de actitud Likert. Resultados: se identificó la necesidad de la elaboración del recurso de aprendizaje para la asignatura matemática. Se diseñó un software educativo para el aprendizaje de los cuatro temas de la asignatura matemática con orientaciones metodológicas para su uso en las clases. Conclusión: el software educativo motiva el aprendizaje, eleva la calidad del proceso docente y estimulan la participación creadora de los estudiantes. Se recomienda la utilización del mismo y continuar su actualización y perfeccionamiento.

ABSTRACT Introduction: educational software plays an important role in the teaching-learning process in Higher Medical Education in Cuba. It is a valuable tool that will contribute significantly to the development of mathematics self-learning. Objective: to propose educational software as a didactic resource for the development of the teaching-learning process of the subject of mathematics in the profession of Surveillance and Vector Control. Methods: a technological development study was conducted in the area of learning resources at Lidia Doce Sánchez Medical Science Affiliate Institution of Mayarí, in the period from January 2018 to June 2019. The target group comprised 39 students of Health Technology Studies and 18 professors of these students and the sample included 27 students and 5 professors who teach the subject of mathematics, chosen intentionally. Theoretical methods were used, and among the empirical methods, the questionnaire, the brainstorming technique and observation. Likert Attitude Scale was used. Results: the need for the development of a learning resource for the subject of mathematics was identified. The educational software was designed for learning the four topics of the subject with methodological guidelines for its application in the program of study. Conclusion: the educational software motivates learning, raises the quality of the teaching process and stimulates the creative participation of students. It is recommended to use it and to continue its update and improvement.

Utilidad diagnóstica del dímero D cuantitativo / Diagnostic usefulness of quantitative D-dimer

Introducción: El dímero D es un marcador de la generación de trombina y plasmina. Constituye el producto final de la degradación de un trombo rico en fibrina mediada por la acción secuencial de 3 enzimas: trombina, factor FXIIIa y plasmina. Las pruebas disponibles en la actualidad para el diagnóstico del dímero D son variadas y no son uniformes. Objetivo: Analizar las evidencias disponibles sobre la utilidad de diferentes pruebas rápidas de dímero D. Métodos: Se realizó una revisión de la literatura de los últimos diez años, en inglés y español, utilizando motores de búsqueda como Google Académico y Pubmed que permitió el acceso a artículos relacionados en revistas arbitradas. Se agrupó y organizó información sobre las posibles utilidades del dímero D. Desarrollo: La determinación en el laboratorio del dímero D, se usa como prueba rápida y sencilla, posee un lugar definido en los algoritmos de exclusión de la enfermedad tromboembólica venosa, en el diagnóstico de coagulación intravascular diseminada y con aplicación en la predicción de la recidiva de trombosis venosa profunda, en los últimos años. Existen diversos ensayos para la determinación de la concentración plasmática de dímero D que utilizan distintas metodologías, diferentes anticuerpos y sensibilidades. Conclusiones: La determinación de dímero D por los métodos cuantitativos en pacientes con trastornos trombóticos es muy importante para determinar su sensibilidad, y fundamentar el desarrollo del algoritmo diagnóstico de las mencionadas entidades(AU)

Introduction: D-dimer is a marker of thrombin and plasmin generation. It is the final product of the degradation of a fibrin-rich thrombus mediated by the sequential action of three enzymes: thrombin, factor XIIIa and plasmin. The tests currently available for D-dimer diagnosis are varied and not uniform. Objective: Analyze the evidence available about the usefulness of a number of D-dimer rapid tests. Methods: A review was conducted of the literature published in English and Spanish in the last ten years, using search engines such as Google Scholar and PubMed, which allowed access to papers about the topic in peer-reviewed journals. Data about the possible uses of D-dimer were grouped and organized. Discussion: Laboratory D-dimer determination is a rapid and simple test that has occupied a definite place in the exclusion algorithms for venous thromboembolic disease, the diagnosis of disseminated intravascular coagulation, and the prediction of deep venous thrombosis recurrence in recent years. A number of assays are available to determine D-dimer plasma concentration. These are based on different methodologies, antibodies and sensitivity values. Conclusions: D-dimer determination by quantitative methods is very important in patients with thrombotic disorders to determine their sensitivity and substantiate the development of the diagnostic algorithm for the aforementioned conditions(AU)

Biogas valorization via continuous polyhydroxybutyrate production by Methylocystis hirsuta in a bubble column bioreactor.

Creating additional value out of biogas during waste treatment has become a priority in past years. Biogas bioconversion into valuable bioproducts such as biopolymers has emerged as a promising strategy. This work assessed the operational feasibility of a bubble column bioreactor (BCB) implemented with gas recirculation and inoculated with a polyhydroxybutyrate (PHB)-producing strain using biogas as substrate. The BCB was initially operated at empty bed residence times (EBRTs) ranging from 30 to 120 min and gas recirculation ratios (R) from 0 to 30 to assess the gas-to-liquid mass transfer and bioconversion of CH4. Subsequently, the BCB was continuously operated at a R of 30 and an EBRT of 60 min under excess of nitrogen and nitrogen feast-famine cycles of 24 h:24 h to trigger PHB synthesis. Gas recirculation played a major role in CH4 gas-liquid transfer, providing almost fourfold higher CH4 elimination capacities (~41 g CH4 m-3 h-1) at the highest R and EBRT of 60 min. The long-term operation under N excess conditions entailed nitrite accumulation (induced by O2 limiting conditions) and concurrent methanotrophic activity inhibition above ~60 mg N-NO2- L-1. Adjusting the N-NO3- supply to match microbial N demand successfully prevented nitrite accumulation. Finally, the N feast-famine 24 h:24 h strategy supported a stable CH4 conversion with a removal efficiency of 70% along with a continuous PHB production, which yielded PHB accumulations of 14.5 ± 2.9% (mg PHB mg-1 total suspended solids × 100). These outcomes represent the first step towards the integration of biogas biorefineries into conventional anaerobic digestion plants.

Implante de marcapasos transitorio en una terapia intensiva municipal / Implantation of temporary pacemaker in a municipal intensive care unit

Introducción: Las bradi-arritmias son cardiopatías graves que ocasionan trastornos hemodinámicos severos; llevar al paciente a un gasto cardiaco normal puede implicar que se implante un marcapasos. Objetivo: Describir algunos aspectos clínicos y epidemiológicos de pacientes que recibieron la técnica de implantar un marcapasos. Métodos: Se realizó un estudio descriptivo y transversal, con 36 pacientes que necesitaron marcapasos transitorio, ingresados en la unidad de cuidados intensivos del Hospital General Docente "Orlando Pantoja Tamayo" de Contramaestre, en el período desde octubre de 2015 hasta mayo de 2019. Las variables utilizadas fueron: grupo de edades y sexo, causas de arritmias y antecedentes patológicos personales, medicamentos más usados previos al ingreso, tiempo de uso del marcapasos transitorio y necesidad de implantación del permanente. Resultados: Predominó el sexo masculino y edades de 80 y más años, el trastorno de la conducción auriculoventricular más frecuente fue el bloqueo auriculoventricular de tercer grado; el tiempo promedio de uso de marcapaso transitorio fue entre 2 y 6 días. Conclusiones: La implantación precoz en esta entidad municipal mejoró notablemente la supervivencia de los pacientes(AU)

Introduction: Bradyarrhythmias are serious heart diseases that cause severe hemodynamic disorders. Bringing the patient to normal cardiac output may imply that a pacemaker be implanted. Objective: To describe some clinical and epidemiological aspects of patients who received the technique of implanting a pacemaker. Methods: A descriptive and cross-sectional study was carried out with 36 patients who needed a temporary pacemaker, admitted to the intensive care unit of Orlando Pantoja Tamayo General Teaching Hospital in Contramaestrem, in the period from October 2015 to May 2019. The variables used were age group and sex, causes of arrhythmias, and personal pathological history, most used medications prior to admission, time of usage of the temporary pacemaker, and the need for permanent implantation. Results: The male sex and ages 80 and older predominated, the most frequent atrioventricular conduction disorder was the third-degree atrioventricular block. The average time of temporary pacemaker usage was between two and six days. Conclusions: Early implantation in this municipal institution significantly improved patient survival(AU)

Ethnobotanical, nutritional and medicinal properties of Mexican drylands Cactaceae Fruits: Recent findings and research opportunities.

The Mexican drylands possess enormous biotic and cultural wealth, representing 65% of the national territory. Approximately 50% of Mexican dryland flora is endemic and accompanied by ample local and traditional knowledge. There are certain types of cactus fruits that are being technologically produced. However, there are other cactus fruit that are underutilized and understudied that could be promoted for their sustainable use. Evidence indicates that the genera of Escontria, Myrtilocactus, Hylocereus, and Stenocereus contain bioactive compounds such as betalains and phenols. Opuntia, the most abundant cactus in Mexico, produces fruit known as prickly pears with bioactive compounds that are associated with health benefits. The purpose of this review is to compile the nutritional and functional properties of selected cactus fruits from the Mexican drylands, as well as their use in the health, food, cosmetic, and agricultural industries in order to establish knowledge gaps and well-supported future research directions.

Evaluation of a panel of tumor-associated antigens in breast cancer.

BACKGROUND: Recent studies indicate that serum from cancer patients contains auto-antibodies against oncoproteins so called tumor-associated antigens (TAAs), which represent promising diagnostic and prognostic biomarkers. OBJECTIVES: In this study we searched for breast cancer-associated auto-antibodies against individual TAAs. Also we evaluated if a panel of multiple TTAs would improve the detection of auto-antibodies. We screened CEA, CCBN1, c-Myc, p53, Ki-67, Nm23, PRDX6, eIF5A, PARK7, GLIO-1, Hsp27 and Hsp70 proteins, previously detected as up-regulated in breast tumors of Mexican patients. METHODS: Enzyme-linked immunosorbent assays (ELISA) were performed to detect auto-antibodies in sera from a cohort of 104 breast cancer patients and 50 sera from healthy individuals. RESULTS: Our data showed that antibodies frequency to any individual TAA was low and ranged from 0.96% to 4.8%. However, the successive addition of multiple TAAs represented by panels of three-to-five TAAs resulted in increased ELISA positive reactions. The first panel of three combined TAAs (p53/PRDX6/CEA) had a sensitivity of 19%, while a second set of four TAAs (p53/PRDX6/c-Myc/Hsp70) reached 28% sensitivity. Likewise, a third panel of five antigens (p53/PRDX6/c-Myc/Hsp70/Nm23) showed 34% sensitivity. CONCLUSIONS: Our data showed that detection of individual autoantibodies against TAAs in the cohort of patients analyzed here was low, which was enhanced by adding multiple TAAs. Data support the notion that frequencies of autoantibodies could be impacted by geographical and heterogeneous genetic factors of breast cancer patients.

Histopatology and HSP70 analysis of the midgut of Rhinocricus padbergi (Diplopoda) in the evaluation of the toxicity of two new metallic-insecticides.

Millipedes are organisms of the edaphic fauna and have been used as bioindicators for the evaluation of pollutants in the environment, as they are in constant contact with the soil. This study used the millipede Rhinocricus padbergi as surrogate to evaluate the toxicity of two metallic-insecticides that has been developed for leaf-cutting ants management. Millipedes were exposed in terrariums containing different concentrations of the metallic-insecticides and, after periods of 21 and 90 days, three individuals from each terrarium were dissected in order to remove the midgut, the organ where absorption of nutrients and, consequently, toxic substances occurs. The toxic action of the metallic-insecticides was analyzed through qualitative and semi-quantitative analysis of morphophysiological alterations and by quantitative analysis of the HSP70 stress protein. The results showed that the metallic-insecticides may increase HSP70 labeling, although not at all concentrations and periods of exposure. Histopathological alterations were not significant at any concentration, indicating that the cytoprotective action of HSP70 is able to prevent severe damage to the midgut. It is therefore suggested that the metallic-insecticides are not toxic to the species studied here as no toxicity was observed under the conditions tested. In addition, stress protein localization in midgut helps understand how morphophysiological processes can potentially be affected by pesticide exposure.

Elucidating the influence of environmental factors on biogas-based polyhydroxybutyrate production by Methylocystis hirsuta CSC1.

The valorization of biogas as a feedstock for the generation of added-value bioproducts will play a key role on the sustainability of anaerobic digestion. The present work assessed the influence of key environmental parameters (O2:CH4 ratio, temperature and nitrogen source) on the growth and polyhydroxybutyrate (PHB) synthesis under nitrogen limiting conditions of the type II methanotroph Methylocystis hirsuta CSC1 using biogas as a feedstock. The O2:CH4 ratios tested (1:1, 1.5:1 and 2:1) did not affect significantly M. hirsuta CSC1 growth yields (~5 g TSS mol-1 CH4), although lower CH4 removal rates were reached under O2-limiting conditions (ratio 1:1). The highest PHB content (45 wt%) was achieved at a ratio 2:1 and was threefold higher than those obtained at lower ratios (~15 wt%). The increase in temperature from 15 to 25 °C resulted in increases in the growth yield (from 5 to 6 g TSS mol-1 CH4) and PHB content (from 32 to 40 wt%). Conversely, the lowest PHB content (30 wt%) was reached at 37 °C, together with a negligible growth under nutrient sufficient conditions. The nitrogen source also played a key role on both M. hirsuta CSC1 growth and PHB synthesis. Thus, ammonium resulted in the highest growth yield (7 g TSS mol-1 CH4), although the maximum PHB content was achieved when biomass was previously grown in nitrate as the nitrogen source (41 wt%). Nitrite exerted an inhibitory effect on M. hirsuta CSC1 growth.

Intoxicaciones exógenas por intentos suicidas en una unidad de cuidados intensivos / Exogenous intoxications due to suicide attempts in an intensive care unit

Introducción: Las intoxicaciones exógenas agudas son tan antiguas como la humanidad. Objetivo: Caracterizar a los pacientes con intoxicación exógena aguda atribuible a intento suicida. Método: Se realizó un estudio descriptivo y retrospectivo de 26 pacientes con el citado diagnóstico, atendidos en la Unidad de Cuidados Intensivos del Hospital General Docente Orlando Pantoja Tamayo de Contramaestre, provincia de Santiago de Cuba, desde enero hasta diciembre de 2017. Las variables analizadas fueron: grupos etarios, sexo, ocupación, tóxicos utilizados por estos pacientes, escala de Glasgow al ingreso, uso del carbón activado y tiempo de empleo, así como tipo de tratamiento. Resultados: En la serie prevalecieron los pacientes de 20-39 y 40-59 años de edad, así como los psicofármacos, seguidos por organofosforados, antiinflamatorios y antihistamínicos como los tóxicos más usados. En más de la mitad de los afectados la escala de Glasgow osciló entre 9 y 13 puntos. El lavado gástrico y el carbón activado fueron los métodos de desintoxicación más empleados. Conclusiones: Las intoxicaciones exógenas constituyen una verdadera urgencia médica, por tanto, es importante tener en cuenta el tiempo trascurrido entre el accidente y el tratamiento. Cuanto más precoz sea la intervención médica requerida, mejor será el pronóstico final de estos pacientes; por ello las acciones en el nivel primario de atención son determinantes.

Introduction: The acute exogenous intoxications are as old as humanity. Objective: To characterize the patients with acute exogenous intoxication attributable to suicide attempt. Method: A descriptive and retrospective study of 26 patients with this diagnosis, assisted in the Intensive Cares Unit of Orlando Pantoja Tamayo Teaching General Hospital in Contramaestre, Santiago de Cuba, was carried out from January to December, 2017. The analyzed variables were: age groups, sex, occupation, toxics used by these patients, Glasgow scale at admission, use of charcoal and time of use, as well as type of treatment. Results: In the series the 20-39 and 40-59 years patients prevailed, as well as the psycho drugs, followed by organophosphorus compounds, anti-inflammatory and histamine antagonists as the most used toxics. In more than half of those affected patients the Glasgow scale oscillated between 9 and 13 points. The gastric lavage and charcoal were the most used detoxification methods. Conclusions: The exogenous intoxications constitute a true medical emergency, therefore, it is important to keep in mind the time between the accident and the treatment. The earlier the required medical intervention, the better will be the final prognosis of these patients; reason why the actions in the primary care level are determining.

Genome scale metabolic modeling reveals the metabolic potential of three Type II methanotrophs of the genus Methylocystis.

Genome Scale Metabolic Models (GSMMs) of the recently sequenced Methylocystis hirsuta and two other methanotrophs from the genus Methylocystis have been reconstructed. These organisms are Type II methanotrophs with the ability of accumulating Polyhydroxyalkanoates under nutrient limiting conditions. For the first time, GSMMs have been reconstructed for Type II methanotrophs. These models, combined with experimental biomass and PHB yields of Methylocystis hirsuta, allowed elucidating the methane oxidation mechanism by the enzyme pMMO (particulate methane monooxygenase) in these organisms. In contrast to Type I methanotrophs, which use the "direct coupling mechanism", Type II methanotrophs appear to use the so called "redox arm mechanism". The utilization of the "redox arm mechanism", which involves the coupling between methane oxidation and complex I of the respiratory chain, was confirmed by inhibition of complex I with catechol. Utilization of the "redox arm" mechanism leads to lower biomass yields on methane compared to Type I methanotrophs. However, the ability of Type II methanotrophs to redirect high metabolic carbon fluxes towards acetoacetyl-CoA under nitrogen limiting conditions makes these organisms promising platforms for metabolic engineering.

Molecular Epidemiology of HIV-1 Virus in Puerto Rico: Novel Cases of HIV-1 Subtype C, D, and CRF-24BG.

HIV-1 subtype B virus is the most prevalent subtype in Puerto Rico (PR), accounting for about 90% of infection in the island. Recently, other subtypes and circulating recombinant forms (CRFs), including F(12_BF), A (01_BF), and CRF-39 BF-like, have been identified. The purpose of this study is to assess the distribution of drug resistance mutations and subtypes in PR. A total of 846 nucleotide sequences from the period comprising 2013 through 2017 were obtained from our "HIV Genotyping" test file. Phylogenetic and molecular epidemiology analyses were performed to evaluate the evolutionary dynamics and prevalence of drug resistance mutations. According to our results, we detected a decrease in the prevalence of protease inhibitor, nucleoside reverse transcriptase inhibitor (NRTI), and non-NRTI (NNRTI) resistance mutations over time. In addition, we also detected recombinant forms and, for the first time, identified subtypes C, D, and CRF-24BG in PR. Recent studies suggest that non-subtypes B are associated with a high risk of treatment failure and disease progression. The constant monitoring of viral evolution and drug resistance mutation dynamics is important to establish appropriate efforts for controlling viral expansion.