A machine-learning regional clustering approach to understand ventilator-induced lung injury: a proof-of-concept experimental study.

BACKGROUND: The spatiotemporal progression and patterns of tissue deformation in ventilator-induced lung injury (VILI) remain understudied. Our aim was to identify lung clusters based on their regional mechanical behavior over space and time in lungs subjected to VILI using machine-learning techniques. RESULTS: Ten anesthetized pigs (27 ± 2 kg) were studied. Eight subjects were analyzed. End-inspiratory and end-expiratory lung computed tomography scans were performed at the beginning and after 12 h of one-hit VILI model. Regional image-based biomechanical analysis was used to determine end-expiratory aeration, tidal recruitment, and volumetric strain for both early and late stages. Clustering analysis was performed using principal component analysis and K-Means algorithms. We identified three different clusters of lung tissue: Stable, Recruitable Unstable, and Non-Recruitable Unstable. End-expiratory aeration, tidal recruitment, and volumetric strain were significantly different between clusters at early stage. At late stage, we found a step loss of end-expiratory aeration among clusters, lowest in Stable, followed by Unstable Recruitable, and highest in the Unstable Non-Recruitable cluster. Volumetric strain remaining unchanged in the Stable cluster, with slight increases in the Recruitable cluster, and strong reduction in the Unstable Non-Recruitable cluster. CONCLUSIONS: VILI is a regional and dynamic phenomenon. Using unbiased machine-learning techniques we can identify the coexistence of three functional lung tissue compartments with different spatiotemporal regional biomechanical behavior.

Transfusión intrauterina, hidrops fetal no inmune: reporte de un caso / Intrauterine transfusion, non-immune fetal hydrops: case report / Transfusão intrauterina, hidropisia fetal não imune: relato de caso

Introducción: el hidrops fetal es grave, de mal pronóstico y alta morbimortalidad, a pesar de mejoras diagnósticas y terapéuticas desarrolladas en los últimos tiempos. El pronóstico estará determinado por la etiología y posibilidades terapéuticas asociadas a mejores resultados, a la edad gestacional, al diagnóstico y al nacimiento, si bien cabe destacar que no existen suficientes estudios de seguimiento a largo plazo. El diagnóstico ecográfico es confirmatorio, siendo la principal complejidad identificar la etiología y plantear la estrategia terapéutica adecuada. Descripción del caso: presentamos una paciente con diagnóstico de hidrops fetal de tipo no inmune y su abordaje terapéutico. La causa del hidrops correspondió a anemia fetal severa, requiriendo la realización de tres procedimientos con exanguinotransfusión parcial intrauterina mediante cordocentesis. A las 33 semanas, se decidió la finalización del embarazo, con buena evolución neonatal. Conclusión: el hidrops fetal aumenta la morbimortalidad fetal y neonatal, siendo un enorme desafío para el equipo tratante, que requiere de un equipo asistencial interdisciplinario. El conocimiento de esta patología permite realizar un abordaje completo, orientar a la etiología, realizando un diagnóstico oportuno y la selección adecuada del tratamiento. Como en este caso, al identificar la anemia severa como causa del hidrops, es mandatorio definir el manejo para los fetos candidatos a terapia intrauterina.

Introduction: fetal hydrops is a serious condition with a poor prognosis and high morbidity and mortality, despite improvements in diagnostics and therapeutics in recent years. Prognosis is determined by the etiology and therapeutic options associated with better outcomes, gestational age, diagnosis, and birth, although it should be noted that there are not enough long-term follow-up studies. Ultrasound diagnosis is confirmatory, with the main challenge being to identify the etiology and propose the appropriate therapeutic strategy. Description of the case: we present a patient diagnosed with non-immune fetal hydrops and its therapeutic approach. The cause of hydrops was severe fetal anemia, requiring 3 procedures with intrauterine partial exsanguination transfusion through Cordocentesis. At 33 weeks, the decision was made to terminate the pregnancy, with good neonatal outcomes. Conclusions: fetal hydrops increases fetal and neonatal morbidity and mortality, posing a significant challenge for the treating team and requiring an interdisciplinary healthcare team. Understanding this condition allows for a comprehensive approach, guiding the etiology, providing timely diagnosis, and selecting appropriate treatment. As in this case, identifying severe anemia as the cause of hydrops mandates defining the management for fetuses eligible for intrauterine therapy.

Introdução: a hidropisia fetal é grave, com mau prognóstico e elevada morbimortalidade, apesar das melhorias diagnósticas e terapêuticas desenvolvidas nos últimos tempos. O prognóstico será determinado pela etiologia e possibilidades terapêuticas associadas a melhores resultados, idade gestacional, diagnóstico e nascimento, embora se deva salientar que não existem estudos suficientes de seguimento a longo prazo. O diagnóstico ultrassonográfico é confirmatório, sendo a principal complexidade identificar a etiologia e propor a estratégia terapêutica adequada. Descrição do caso: apresentamos uma paciente com diagnóstico de hidropisia fetal não imune e sua abordagem terapêutica. A causa da hidropisia correspondeu a anemia fetal grave, sendo necessária a realização de 3 procedimentos com exsanguineotransfusão intrauterina parcial por meio de cordocentese. Às 33 semanas foi decidida a interrupção da gravidez, com boa evolução neonatal. Conclusão: a hidropisia fetal aumenta a morbimortalidade fetal e neonatal, sendo um enorme desafio para a equipe responsável pelo tratamento, necessitando de uma equipe de atendimento interdisciplinar. O conhecimento desta patologia permite uma abordagem completa, orientação sobre a etiologia, diagnóstico atempado e seleção do tratamento adequado. Assim como neste caso, quando se identifica anemia grave como causa da hidropisia, é obrigatória a definição do manejo para os fetos candidatos à terapia intrauterina.

Guía de manejo obstétrico y del recién nacido en madre aloinmunizada / Guidelines for the obstetric management of an alloimmune mother and her newborn / Guia de manejo obstétrico e neonatal em mães aloimunizadas

Resumen: La aloinmunización es una respuesta biológica frente a la exposición de antígenos no propios. La gestación, las transfusiones de hemocomponentes, los trasplantes de órganos sólidos y células hematopoyéticas, así como el consumo de drogas intravenosas exponen a las pacientes al desarrollo de aloanticuerpos antieritrocitarios. El hallazgo de los mismos debe cumplir con las instancias diagnósticas para identificar la probabilidad de estar asociados a enfermedad hemolítica feto neonatal (EHFN) y su oportuna derivación a policlínica de alto riesgo obstétrico (ARO) para su correcto seguimiento. Es fundamental que sean los laboratorios de inmunohematología de los servicios de hemoterapia y medicina transfusional los encargados de los estudios diagnósticos de aloinmunización eritrocitaria(1). En este sentido hemos elaborado esta guía con el objetivo de protocolizar de manera multidisciplinaria el manejo de las embarazadas aloinmunizadas y sus recién nacidos.

Abstract: Alloimmunization is the biological response to exposure to non-HLA antigens. Pregnancy, transfusion of blood components, solid organ and hematopoietic cell transplantation, as well as intravenous drug use expose patients to the development of anti-erythrocyte antibodies. When the latter are found, they must match diagnostic criteria to identify the potential association to hemolytic disease of the fetus and newborn (HDFN) and its timely referral to the high-risk obstetric risk polyclinic for due follow-up. It is of the essence for erythrocyte alloimmunization diagnostic tests to be carried out by the immunohematology laboratories of the Hemotherapy and Transfusional Medicine services. To that end, we have prepared these guidelines with the purpose of providing a multidisciplinary protocol for the handling of maternal alloimmunization and alloimmunization of the newborn.

Resumo: A aloimunização é uma resposta biológica à exposição a antígenos não próprios. A gravidez, as transfusões de hemocomponentes, os transplantes de órgãos sólidos e células hematopoiéticas, bem como o uso de drogas intravenosas expõem os pacientes ao desenvolvimento de anticorpos antieritrocitários. O achado destes deve obedecer a critérios diagnósticos para identificar a doença e a probabilidade de estarem associados a doença hemolítica feto neonatal (DHPN) e seu encaminhamento oportuno para uma unidade de alto risco obstétrico para acompanhamento adequado. É fundamental que os laboratórios de imuno-hematologia dos serviços de Hemoterapia e Medicina Transfusional se encarreguem dos estudos diagnósticos da aloimunização eritrocitária. Elaboramos este guia com o objetivo de estabelecer um protocolo multidisciplinar para o manejo de gestantes aloimunizadas e seus recém-nascidos.

Hypoxic-Ischemic Encephalopathy and Mitochondrial Dysfunction: Facts, Unknowns, and Challenges.

Significance: Hypoxic-ischemic events due to intrapartum complications represent the second cause of neonatal mortality and initiate an acute brain disorder known as hypoxic-ischemic encephalopathy (HIE). In HIE, the brain undergoes primary and secondary energy failure phases separated by a latent phase in which partial neuronal recovery is observed. A hypoxic-ischemic event leads to oxygen restriction causing ATP depletion, neuronal oxidative stress, and cell death. Mitochondrial dysfunction and enhanced oxidant formation in brain cells are characteristic phenomena associated with energy failure. Recent Advances: Mitochondrial sources of oxidants in neurons include complex I of the mitochondrial respiratory chain, as a key contributor to O2•- production via succinate by a reverse electron transport mechanism. The reaction of O2•- with nitric oxide (•NO) yields peroxynitrite, a mitochondrial and cellular toxin. Quantitation of the redox state of cytochrome c oxidase, through broadband near-infrared spectroscopy, represents a promising monitoring approach to evaluate mitochondrial dysfunction in vivo in humans, in conjunction with the determination of cerebral oxygenation and their correlation with the severity of brain injury. Critical Issues: The energetic failure being a key phenomenon in HIE connected with the severity of the encephalopathy, measurement of mitochondrial dysfunction in vivo provides an approach to assess evolution, prognosis, and adequate therapies. Restoration of mitochondrial redox homeostasis constitutes a key therapeutic goal. Future Directions: While hypothermia is the only currently accepted therapy in clinical management to preserve mitochondrial function, other mitochondria-targeted and/or redox-based treatments are likely to synergize to ensure further efficacy.

Hemorragia alveolar difusa no inmune en pediatría / Non-inmune mediated diffuse alveolar hemorrage in children / A hemorragia alveolar difusa não imune em pediatria

Resumen: La hemorragia alveolar difusa no inmune es una patología poco frecuente tanto en la población pediátrica como en los adultos. Si bien se conocen factores determinantes de dicha patología, la interacción de éstos a la hora de producirse el sangrado no es del todo comprendida. Para cumplir con la función de intercambio gaseoso la membrana alvéolo-capilar debe tener un espesor bajo, lo que la expone a falla por estrés y eventualmente extravasación de sangre al parénquima pulmonar. La membrana basal, sumado a la disposición de los alvéolos y el intersticio pulmonar, le dan resistencia extraordinaria a dicha membrana. Si ocurre efracción de la membrana alvéolo capilar puede haber pasaje de sangre al alvéolo e intersticio pulmonar, este fenómeno es conocido como falla por estés. En los casos que existe fragilidad de la membrana alvéolo-capilar, ya sea por inmadurez o por situaciones patológicas, existe un riesgo significativo de efracción de la misma. Alteraciones hemodinámicas y de la cascada de la coagulación pueden ser factores determinantes en el desarrollo de hemorragia alveolar. En el presente trabajo se discuten cuatro casos clínicos de hemorragia alveolar difusa no inmune y en base a éstos se desarrolla una hipótesis con el objetivo de explicar la interrelación de los factores que inciden en el desarrollo de dicha entidad.

Summary: Non-immune mediated alveolar hemorrhage is a rare pathology affecting both children and adults. Although the causes of this disease are known, their interaction in case of bleeding is not clearly understood. The present paper discusses 4 clinical cases of non-immune mediated alveolar hemorrhage and a hypothesis is presented with the objective of explaining the interrelation of the factors that may affect the its development. In order to comply with the gas exchange function, the alveolar-capillary membrane must not be too thick, since this might lead to stress failure and to eventual blood extravasation to the lung parenchyma. The basement membrane (type IV) collagen, plus the alveoli arrangement and the pulmonary interstitium, provide extraordinary resistance to such membrane. Whenever the alveolar-capillary membrane is weak, either due to immaturity or to pathological situations, there is a significant risk of rupture. Hemodynamic and coagulation alterations can be determining factors in the development of this pathology, since they affect the development of stress failure or perpetuate the passage of blood to the pulmonary interstitium.

Resumo: A hemorragia alveolar não imune é uma patologia rara tanto nas crianças como nos adultos. Embora os determinantes dessa patologia sejam conhecidos, sua interação no momento de determinar o sangramento não é completamente compreendida. Neste estudo discutimos quatro casos clínicos de hemorragia alveolar não imune e desenvolvimos hipóteses para explicar a inter-relação de fatores que afetam o desenvolvimento da doença. Para que a membrana possa cumprir a sua função de troca de gás alveolar-capilar deve ter baixa espessura, o que a expõe à tensão de ruptura e, eventualmente, o extravasamento de sangue para o parênquima pulmonar. O colagénio tipo IV da membrana basal, adicionado à disposição dos alvéolos e ao interstício pulmonar, confere extraordinária resistência à referida membrana. Nos casos nos que há fragilidade da membrana alvéolo-capilar, seja por imaturidade ou por situações patológicas, existe risco significativo de sua ruptura. Alterações hemodinâmicas e de coagulação podem ser fatores determinantes no desenvolvimento dessa patologia, uma vez que afetam o desenvolvimento de falha de estresse ou perpetuam a passagem do sangue para o interstício pulmonar.

Administración de surfactante profiláctico por vía orofaríngea previo al pinzamiento de cordón umbilical en el recién nacido de muy bajo peso en la maternidad del Hospital Universitario / Prophylactic oropharyngeal surfactant administration before cord clamping in very low birth weight newborns at the University Children Hospital Maternity Department / Administração de surfactante profilático por via orofaríngea antes do clampeamento do cordão umbilical em recém-nascidos de baixo peso extremo na Maternidade do Hospital Pediátrico Universitário

Resumen: En la era de la búsqueda de estrategias ventilatorias mínimamente invasivas, la administración profiláctica de surfactante con técnicas sencillas, que no requieren elevada destreza y que pueden ser realizadas en ámbitos de baja complejidad, deben ser investigadas para potencialmente disminuir la morbilidad y mortalidad del pretérmino. Se reporta el uso de surfactante en la orofaringe de cuatro recién nacidos de muy bajo peso (promedio de peso de 1.236 g y 28 semanas de edad gestacional), y concomitante colocación de presión positiva continua por pieza nasal antes de la primera inspiración extrauterina manteniendo el cordón intacto. No se registraron efectos adversos y la aspiración gástrica posterior demostró que el surfactante fue inspirado a los pulmones del recién nacido. La administración de surfactante orofaríngeo es una técnica innovadora, segura, factible y reproducible. A la vez que minimizamos los riesgos de posible iatrogenia por la técnica utilizada, facilitamos una transición cardiovascular más estable, manteniendo la circulación fetoplacentaria.

Summary: In the era of minimally invasive ventilatory procedures, the prophylactic administration of surfactant using simple techniques that can be performed in low complexity settings, should be researched as a tool to potentially reduce preterm morbidity and mortality. We report the use of oropharyngeal surfactant in 4 very low birth weight newborns (average birth weight 1236g and 28 weeks of gestational age) and of continuous positive airway pressure before the first intrauterine inspiration and keeping an intact umbilical cord. No adverse effects happened, and the aspiration of gastric residual confirmed that surfactant had reached the lungs. The administration of oropharyngeal surfactant is an innovative, safe, feasible and reproducible technique. It minimizes the risks of possible iatrogenesis due to the technique used, and it also facilitates a more stable cardiovascular transition, maintaining the fetus' placental circulation.

Resumo: Na era da procura de técnicas ventilatórias minimamente invasivas, a administração profilática de surfactante utilizando técnicas simples, que não requerem muita destreza e que pode ser realizada em contextos de baixa complexidade, deve ser pesquisada para reduzir potencialmente a morbidade e mortalidade dos pré-termos. Reportamos o uso de surfactante na orofaringe em 4 recém-nascidos com baixo peso ao nascimento (peso médio de 1,236 g e 28 semanas de idade gestacional), e colocação concomitante de pressão positiva contínua por adaptador nasal, antes da primeira inspiração extrauterina e mantendo o cordão umbilical intacto. Não houve efeitos adversos e o aspirado gástrico subsequente mostrou que o surfactante foi inspirado e observado nos pulmões dos recém-nascidos. O surfactante de administração orofaríngea é uma técnica inovadora, segura, viável e reprodutível. Minimiza os riscos iatrogênicos eventuais devido à técnica utilizada, à vez que proporciona uma transição cardiovascular mais estável porque mantém a circulação da placenta fetal.

Efficacy and safety of a novel nitric oxide generator for the treatment of neonatal pulmonary hypertension: Experimental and clinical studies.

Persistent pulmonary hypertension of the newborn (PPHN) is a complex pathology resulting from a failure of the post-natal reduction in pulmonary vascular resistance leading to hypoxemia. The standard therapy is inhaled Nitric Oxide (NO) improving oxygenation but its availability is limited, especially in hospitals with restricted financial resources. We evaluated the efficacy and safety of a new device generating NO (TAS + PLUS), in three experimental piglet models of pulmonary hypertension (PH), and we later tested its application in a pilot study of newborn patients suffering from PPHN. Piglets with experimentally induced PH showed a decrease in pulmonary arterial pressure (PAP) after breathing NO. Both acute and chronic exposure of piglets and rats did not cause any adverse effect in blood gas levels and biological parameters. A pilot study including 32 patients suffering from PPHN showed an increase in oxygen saturation (SatO2) and partial pressure of oxygen in arterial blood (PaO2) leading to a decrease of Oxygenation Index (OI) after compassionate treatment with NO from TAS + PLUS device. The device showed effectiveness and safety both in experimental PH and in the clinical setting. Therefore, it represents an excellent alternative for PPHN management in conditions where commercial NO is unavailable.

Modelo experimental en cerdo recién nacido para el estudio y entrenamiento en ultrasonografía pulmonar del niño crítico / Experimental newborn piglet model for studying and training lung ultrasound in critically ill children

Introducción: la ultrasonografía pulmonar en el paciente crítico (LUCI) ha generado creciente interés en el escenario de los cuidados intensivos. Los modelos animales son herramientas útiles para facilitar el aprendizaje y entrenamiento de los profesionales que la practican. Presentamos el desarrollo de un modelo animal para el estudio y entrenamiento de LUCI en niños críticos. Material y métodos: se utilizó un cerdo recién nacido al que se realizó anestesia, traqueostomía, intubación traqueal y ventilación mecánica (VM) con monitorización convencional. Se aplicaron diferentes niveles de presión telespiratoria (PEEP), se produjo neumotórax y derrame pleural mediante colocación de drenaje en tórax e introducción de aire y suero respectivamente. Se realizó ultrasonografía con transductor lineal de 4-8 MHz. Previo al experimento 12 profesionales recibieron un curso introductorio sobre LUCI dictado por un radiólogo, para luego observar las diferentes secuencias y practicar LUCI con el animal. Resultados: se obtuvieron imágenes de secuencias pulmonares básicas y sus signos característicos: aireación pulmonar normal en VM basal, confirmación de intubación, sobredistensión y colapso pulmonar, neumotórax y derrame pleural. Todos los participantes encontraron a la experiencia positiva y pudieron identificar las diferentes secuencias ultrasonográficas programadas. Conclusiones: el modelo animal que se presenta permitiría el entrenamiento en LUCI de los profesionales que atienden niños críticos. Asimismo, esto posibilitaría el desarrollo de investigación en patología respiratoria pediátrica.

Background: lung ultrasound in the critically ill (LUCI) has generated growing interest in the intensive care scenario. Animal models are useful tools for training professionals in its practice. We present an animal model designed for studying and training in LUCI for critically ill children. Method: a newborn piglet was anesthetized, traqueostomized, intubated and mechanically ventilated (MV) with conventional monitoring. Different levels of PEEP were applied, and pneumothorax and pleural effusion were produced by the insertion of a thoracic drainage and instillation of air and a saline solution. Lung ultrasound was performed by using a 4-8 MHz linear probe. Prior to the experiment, 12 trainees with no previous experience attended a theoretical course on basic LUCI delivered by a radiologist. Subsequently, they visualized and practiced LUCI in the animal model. Results: basic lung ultrasound sequences were obtained, where their typical signs could be seen: normal lung ventilation during standard MV, confirmation of endotracheal tube position, lung overdistension and collapse, pneumothorax and pleural effusion. All trainees found the experience was positive and could identify every sonographic sequence. Conclusions: the animal model presented in the study could allow professionals caring for critically ill children to receive training in LUCI. Likewise, it could allow the development of research in pediatric respiratory pathology.

Intubación al nacer con tubo nasal corto en la transición a la vida extrauterina en recién nacidos de muy bajo peso / Intubation with a short nasal tube at birth during the transition to extrauterine life in very low birth weight infants

Describimos cambios recientes en el cuidado convencional al nacer en recién nacidos de muy bajo peso al nacer y la utilización de un tubo nasal corto para apoyar la ventilación inicial en este nuevo contexto. Reportamos nuestra experiencia con los tres primeros casos en que usamos esta técnica simple para administrar nCPAP a recién nacidos durante el alumbramiento mientras existe función placentaria antes de cortar el cordón.

We describe recent changes in conventional care at birth of very low birth weight infants and the use of a short nasal tube to support ventilation. We report our experience in the first three cases with this simple technique to deliver nCPAP to newborn infants during the third stage of labour, while the placenta is still functioning and before cutting the cord

Uso de óxido nítrico inhalado en el tratamiento de la dificultad respiratoria temprana en el recién nacido pretérmino inmaduro y pretérmino tardío. Reporte de dos casos clínicos / Inhaled nitric oxide in the treatment of early respiratory failure in the late preterm and early term newborn. Report of two cases

La falla en la transición de la circulación fetal a la neonatal puede ser causada por la persistencia de resistencias vasculares elevadas, lo que induce al síndrome de hipertensión pulmonar (HPPN) que ocurre en aproximadamente 2 de cada 1.000 recién nacidos. La HPPN severa se asocia con recién nacidos de término o cercanos al término, si bien puede verse en recién nacidos prematuros. El tratamiento estándar de oro es el óxido nítrico inhalado (ONi) en neonatos con falla respiratoria hipóxica e HPPN. En el Departamento de Neonatología del Hospital de Clínicas de Montevideo se utilizó un generador in situ de óxido nítrico-NO- (TAS+plus®) portátil, capaz de producir continuamente el gas para ser entregado al recién nacido. Su bajo costo y accesibilidad han ampliado sus indicaciones en pacientes con asistencia ventilatoria mecánica (AVM), presión positiva continua en la vía aérea a través de cánula nasal (CPAP nasal) o bajo carpa cefálica. Presentamos dos pacientes con dificultad respiratoria, en los que una vez descartada cardiopatía congénita estructural y con evidencia ecocardiográfica de HPPN se administró ONi, concomitante al soporte respiratorio con CPAP nasal, con el objetivo de evitar la progresión de la enfermedad respiratoria y AVM. Dichos pacientes de 32 y 37 semanas, presentaron buena evolución de su dificultad respiratoria. La mejoría de la falla respiratoria hipóxica mediante la administración de ONi, sin necesidad de ventilación invasiva, fue posible, de bajo costo y fácil de aplicar a los pacientes, incorporando la utilización de un novel generador de ONi en la práctica clínica.

Failure in transition from fetal to neonatal circulation can be caused by the persistence of elevated vascular resistance, which can lead to pulmonary hypertension syndrome (HPPN), occuring in approximately 2 out of 1,000 live newborns. Severe HPPN is associated with term or near term newborns, although it may be seen in preterms. The gold standard treatment is inhaled nitric oxide (NOi) in neonates with hypoxic respiratory failure and HPPN. In the Department of Neonatology of the University Hospital in Montevideo, a portable, in situ generator of nitric oxide-NO- (TAS+plus®) was used, which is capable to continuously produce the gas to be delivered to the newborn. Its low cost and accessibility have expanded its indications to patients with mechanical ventilation (MVA), continuous positive airway pressure through nasal cannula (nasal CPAP) or cephalic carp. We present two patients with respiratory distress, in whom, once the structural congenital heart disease and echocardiographic evidence of HPPN were discarted, NOi was administered, concomitant with nasal CPAP, in order to avoid the progression of respiratory disease and AVM. These patients of 32 and 37 weeks presented good evolution of their respiratory difficulty. The improvement of hypoxic respiratory failure through the administration of NOi, without the need for invasive ventilation, was possible, low cost and easy to apply to patients, incorporating the use of a novel ONi generator in clinical practice.

Documentación filmográfica de la ventilación mecánica en un modelo animal / Filmed documentation of mechanical ventilation in an animal model

Introducción: el aprendizaje de la ventilación mecánica (VM) pediátrica requiere de tiempo y diversas estrategias educativas. En los últimos años se han utilizado los videopodcast para la educación médica. Objetivos: documentación filmográfica de los elementos básicos de la mecánica respiratoria durante la VM en un modelo animal. Creación de un videopodcast para la formación de recursos humanos especializados en VM pediátrica. Metodología: se prepararon diferentes secuencias de VM con ventilador y en forma manual. Se realizó exposición pulmonar mediante toracotomía y VM convencional en un cerdo. Se grabó simultáneamente lo monitorizado por el ventilador y la visualización in vivo del pulmón expuesto ante cada secuencia. Dos especialistas en cuidados intensivos pediátricos analizaron durante la edición las grabaciones y confeccionaron un guión explicativo de lo observado. Resultados: se editó un video con las diferentes secuencias previstas: VM basal, VM sin presión positiva teleespiratoria (PEEP), VM con niveles incrementales de PEEP, VM con bolsa autoinflable, aspiración de sonda endotraqueal con circuito cerrado y abierto durante VM con ventilador y manual con operador. Se editó un videopodcast con leyendas explicativas. Discusión: la utilización de recursos digitales para la enseñanza y divulgación de diversas especialidades médicas es cada vez más frecuente. El videopodcast se ha expandido como una nueva herramienta educativa. Se construyó un modelo para la capacitación de los recursos humanos en VM mediante este formato. La experiencia servirá para construir una videoteca universitaria dirigida a la enseñanza de cuidados críticos del niño y para la divulgación de experimentos biomédicos.

Introduction: learning about mechanical ventilation (MV) in pediatrics requires time and several educational strategies. In recent years, videopodcast has been used for medical training. Objectives: to prepare a filmed documentary of the basic elements in respiratory mechanics during MV in an animal model. To create a videopodcast to train human resources specialized in MV in pediatrics. Material: different sequences of MV with ventilator and manual ventilation were prepared. Lungs were accessed through thoracotomy and MV was started in a pig. Monitored data from the ventilator was simultaneously recorded, the same as the live visualization of the visible lung for each sequence. Two specialists in pediatrics intensive care analysed the recording while it was edited and composed a script explaining what was observed. Results: a video was edited with the different sequences expected: basal MV, MV with zero PEEP, increasing PEEP levels, MV with self-inflating bag, traqueal suction with open and closed traqueal suction systems and manual ventilation with an operator. A videopodcast with explanatory subtitles was edited. Discussion: digital resources are increasingly being used to train physicians and disseminate several medical techniques. Today, videopodcast constitutes a new educational tool. A model was designed to train human resources in MV under this format. This experience will be used to build up a new university video library to assist the training in pediatric critical care and to disseminate biomedical experiments.

After cellular internalization, quercetin causes Nrf2 nuclear translocation, increases glutathione levels, and prevents neuronal death against an oxidative insult.

In this work we describe the protective effects of quercetin against H(2)O(2) in 24-h-pretreated neuronal cultures. We explored quercetin availability and subcellular fate through the use of HPLC-Diode Array Detection (DAD), epifluorescence, and confocal microscopy. We focused on quercetin modulation of thiol-redox systems by evaluating changes in mitochondrial thioredoxin Trx2, the levels of total glutathione (GSH), and the expression of the gamma-glutamate-cysteine ligase catalytic subunit (GCLC), the rate-limiting enzyme of GSH synthesis, by the use of Western blot, HPLC, and real-time PCR techniques, respectively. We further explored the activation of the protective NF-E2-related factor 2 (Nrf2)-dependent signaling pathway by quercetin using immunocytochemistry techniques. Our results showed rapid quercetin internalization into neurons, reaching the nucleus after its addition to the culture. Quercetin pretreatment increased total GSH levels, but did not increase Trx2. Interestingly it caused Nrf2 nuclear translocation and significantly increased GCLC gene expression. At the moment of H(2)O(2) addition, intracellular quercetin or related metabolites were undetectable in the cultures although quercetin pretreatment prevented neuronal death from the oxidant exposure. Our findings suggest alternative mechanisms of quercetin neuroprotection beyond its long-established ROS scavenging properties, involving Nrf2-dependent modulation of the GSH redox system.

Cytoprotection by neutral fraction of tannat red wine against oxidative stress-induced cell death.

Some of the beneficial effects of the Mediterranean diet on human pathologies have been attributed to red wine polyphenols. It has been postulated that the antioxidant activity of the latter would be also responsible for the cytoprotective capacity of red wine that has been reported in a few papers. Nevertheless, red wine shows a complex composition, and the active fraction is not known yet. In this context, the protective capacity of total lyophilized extracts of red wine and anthocyanin, neutral, or acidic fractions, was explored in PC12 cells in culture after a hydrogen peroxide insult. Although all fractions showed high antioxidant activity, only the neutral fraction was cytoprotective. The analysis of this active fraction showed that it was rich in the aglycons quercetin and myricetin as well as the glycosides of kaempferol, isorhamnetin, epicatechin, and catechin, some of which are known to be cytoprotective. This is the first paper to reveal the active fraction of total wine responsible of its cytoprotection.

Cell culture protection and in vivo neuroprotective capacity of flavonoids.

Flavonoids are an important group of recognized antioxidants ubiquitous in fruits, vegetables and herbs. There are epidemiological evidences for the stroke-protecting capacity of flavonoids and while the neuroprotective power of complex extracts rich in flavonoids like those of Ginkgo biloba, green tea or lyophilized red wine have been demonstrated in several studies, neuroprotection by individual flavonoids has been poorly studied in vivo. The neuroprotective capacity of individual flavonoids was studied in PC12 cells in culture and in a model of permanent focal ischemia (permanent Middle Cerebral Artery Occlusion - pMCAO). In the in vivo experiments, flavonoids were administered in lecithin preparations to facilitate the crossing of the blood brain barrier. The simultaneous incubation of PC12 cells with 200 micro M hydrogen peroxide (H2O2) and different flavonoids for 30 min resulted in a conspicuous profile: quercetin, fisetin, luteolin and myricetin significantly increased cell survival while catechin, kaempherol and taxifolin did not. Quercetin was detected in brain tissue 30 min and 1 h after intraperitoneal administration. When one of the protective flavonoids (quercetin) and one of those that failed to increase PC12 cell survival (catechin) were assessed for their protective capacity in the pMCAO model, administered i.p. 30 min after vessel occlusion, quercetin significantly decreased the brain ischemic lesion while catechin did not. It is concluded that when administered in liposomal preparations, flavonoids structurally related to quercetin could become leads for the development of a new generation of molecules to be clinically effective in human brain ischemia.