31 research outputs found
Efecto de la hipoxia moderada en la adaptación pulmonar, estado oxidativo y respuesta inflamatoria en ratones nacidos en hipoxia con transición a aire ambiente y/o sometidos a 100% de oxígeno extraútero
El oxígeno, necesario para la vida y los procesos metabólicos del organismo, puede causar daño celular y tisular por el incremento de especies reactivas del oxígeno, llegando a producir un estrés oxidativo. De hecho, la propia transición fetal neonatal (TFN) supone un estrés oxidativo fisiológico para el feto que pasa de un ambiente de relativa hipoxemia, de 3,5-4,4 kPa, a 10.5 kPa en el momento del nacimiento, en pocos minutos. Pero este estrés oxidativo, en condiciones normales, es necesario para el desarrollo y funcionamiento del organismo. Es en otras situaciones como el nacimiento prematuro, en el que el sistema antioxidante no está completamente maduro, cuando se produce un desequilibrio y puede tener un efecto perjudicial. Además, en estos casos, es más probable que el recién nacido necesite un aporte suplementario de oxígeno para alcanzar la adaptación postnatal.
Sabemos que la suplementación con altas concentraciones de oxígeno provoca un estrés oxidativo que puede dar lugar posteriormente a patologías que son muy frecuentes en el prematuro, habiéndose acuñado el término de “Enfermedad por radicales de oxígeno en el recién nacido”, que incluye entre otras el síndrome de distrés respiratorio y la displasia broncopulmonar, la cual sigue siendo la morbilidad más frecuente en el prematuro que sobrevive.
Existen estudios en los cuales el uso de una hipoxia precondicionante minimiza el daño posterior producido por estrés oxidativo, favoreciendo un estado celular más reductor y por tanto más preparado para afrontar un desequilibrio posterior. Se ha visto que protege, por ejemplo, frente a una hipoxia aguda mejorando la función pulmonar en ratones, atenúa el daño pulmonar secundario a intervenciones quirúrgicas o mejora la capacidad de reparación de las células del estroma mesenquimal del pulmón.
El objetivo principal de este trabajo es evaluar el efecto protector a nivel pulmonar de un nacimiento en condiciones de hipoxia precondicionante frente a un insulto hiperóxico posterior con 100% de oxígeno utilizando crías de ratón recién nacidas. Para ello se utilizó un modelo experimental de TFN con ratones gestantes en una cámara de oxigenación controlada y se dividieron en 3 grupos de estudio: el grupo control, Nx21/21, en el cual se produjo el nacimiento en aire ambiente (FiO2=0.21) y las crías se dejaron en esa concentración de oxígeno hasta su sacrificio a día 1 (P1) y 7 (P7); el grupo experimental Nx21/100, en el cual el nacimiento se produce en aire ambiente y a las 8 horas del nacimiento las crías fueron sometidas a un insulto hiperóxico (FiO2=1.0) durante 1 hora y fueron sacrificadas a día P1 y P7; y por último el grupo experimental Hx14/100, en el que el nacimiento se produce bajo condiciones hipóxicas (FiO2=0.14) y posteriormente se someten las crías a un insulto hiperóxico (1 hora, FiO2=1,0) para su posterior sacrificio a día P1 y P7.
En el pulmón se evaluó el estrés oxidativo a través de la vía de la transulfuración y de los biomarcadores de daño a proteínas y lípidos en tejido pulmonar, así como el estado de la defensa antioxidante, inflamación y por último histología y niveles de apoptosis en pulmones de crías de ratón.
Los resultados mostraron un aumento de la síntesis de GSH a través de la activación de la vía de la transulfuración por el aumento de la Cbs en el grupo nacido bajo condiciones hipóxicas. Además, este mismo grupo mostró una disminución de biomarcadores de daño proteico (m-Tyr/Phe, 3Cl-Tyr/p-Tyr y 3-Tyr/p-Tyr) y de biomarcadores de daño a lípidos (PGE2, PGF2α, 8-iso-PGE2, 8-iso-PGF2 8-iso-15-KetoPGE2, 8-iso-15-KetoPGF2, isoprostanos totales e isofuranos totales). Respecto a la defensa antioxidante, la hipoxia precondicionante aumenta la expresión génica de la catalasa y se obtienen niveles bajos de peróxidos. En el grupo nacido en condiciones de hipoxia precondicionante no sólo observamos una mejora a nivel de estrés oxidativo, sino también a nivel inflamatorio ya que se obtiene la disminución de la expresión génica de TNF-α e interleucina 1-β (IL-1β) y un aumento de la expresión génica de la citoquina antiinflamatoria IL-6.
Por último, se analizó la histología de cortes de pulmón mediante parámetros morfométricos como el grosor de los septos alveolares y el MLI, y el estudio de muerte celular a través del análisis de la caspasa-3 observando en general que el nacimiento en condiciones de hipoxia precondicionante conservaba la estructura de los alveolos y producía una menor muerte celular frente el nacimiento en aire ambiente con posterior hiperoxia.
Por tanto, podemos concluir que el nacimiento en condiciones de hipoxia precondicionante, podría proteger frente a un insulto hiperóxico posterior, causando un menor estrés oxidativo, menor inflamación y un menor daño tisular pulmonar. Estos resultados podrían abrir la puerta a nuevos estudios sobre la hipoxia precondicionante y su aplicación a nivel clínico, dada la importancia de mejorar la morbilidad respiratoria de los recién nacidos prematuros.Oxygen, necessary for life and the metabolic processes, may produce cellular and tissue injury due to the increase of reactive oxygen species, leading to oxidative stress. Indeed, the fetal to neonatal transition itself involves physiological oxidative stress for the fetus, which goes from an environment of relative hypoxemia of 3.5-4.4 kPa to 10.5 kPa at birth in a few minutes. However oxidative stress, under normal conditions, is necessary for the development and functioning of the organism. It is in other situations such as premature birth, where the antioxidant system is not fully mature, that an imbalance occurs and can have a detrimental effect. Moreover, in these cases, the newborn is more likely to need supplemental oxygen to achieve postnatal adaptation.
We know that supplementation with high concentrations of oxygen causes oxidative stress that can subsequently lead to pathologies that are very frequent in the premature infant, the term "Oxygen radical disease in the newborn" having been coined, which includes among others, respiratory distress syndrome of the newborn and bronchopulmonary dysplasia, which remains the most frequent morbidity in the surviving premature infant.
Studies have shown that the use of preconditioning hypoxia minimizes the subsequent damage produced by oxidative stress, favoring a more reductive cellular state and therefore more prepared to face a subsequent imbalance. It has been shown, for example, to protect against acute hypoxia by improving lung function in mice, attenuate lung injury secondary to surgical interventions or improve the repair capacity of lung mesenchymal stromal cells.
The main objective of this work is to evaluate the protective effect at the lungs of a birth under preconditioning hypoxia conditions versus a subsequent hyperoxic insult with 100% oxygen using newborn mouse pups. For this purpose, an experimental model of fetal to neonatal transition was used with pregnant mice in a controlled oxygenation chamber and divided into 3 study groups: the control group, Nx21/21, in which birth occurred in room air (FiO2=0. 21) and the pups were left in that oxygen concentration until sacrifice at day 1 (P1) and 7 (P7); the experimental group Nx21/100, in which birth occurred in room air and 8 hours after birth the pups were subjected to a hyperoxic insult (FiO2=1. 0) for 1 hour and were sacrificed at day P1 and P7; and finally, the experimental group Hx14/100, in which birth occurred under hypoxic conditions (FiO2=0.14) and the pups were subsequently subjected to a hyperoxic insult (1 hour, FiO2=1.0) for subsequent sacrifice at day P1 and P7.
In the lung, oxidative stress was evaluated through the trans-sulfuration pathway and biomarkers of protein and lipid damage in lung tissue, as well as the status of antioxidant defense, inflammation and finally histology and apoptosis levels in mouse pup lungs.
The results showed an increase in GSH synthesis through activation of the trans-sulfuration pathway by increasing Cbs in the group born under hypoxic conditions. In addition, this same group showed a decrease of protein damage biomarkers (m-Tyr/Phe, 3Cl-Tyr/p-Tyr and 3-Tyr/p-Tyr) and lipid damage biomarkers (PGE2, PGF2α, 8-iso-PGE2, 8-iso-PGF2 8-iso-15-KetoPGE2, 8-iso-15-KetoPGF2, total isoprostanes and total isofurans). Regarding antioxidant defense, preconditioning hypoxia increases catalase gene expression and low levels of peroxides are obtained. In the hypoxia-born group we not only observed an improvement at the oxidative stress level, but also at the inflammatory level since we obtained a decrease in the gene expression of TNF-α and interleukin 1-β (IL-1β) and an increase in the gene expression of the anti-inflammatory cytokine IL-6.
Finally, the histology of lung sections was analyzed using morphometric parameters such as the thickness of alveolar septa and MLI, and the study of cell death through caspase-3 analysis observing in general that birth under preconditioning hypoxia conditions preserved the structure of the alveoli and produced less cell death compared to birth in room air with subsequent hyperoxia.
Therefore, we can conclude that birth under preconditioning hypoxia conditions could protect against a subsequent hyperoxic insult, causing less oxidative stress, less inflammation and less lung tissue injury. These results could open up doors to new studies on preconditioning hypoxia and its application at the clinical level, given the importance of improving respiratory morbidity in preterm infants
Mass spectrometric detection of biomarkers for early assessment of intraamniotic fluid infection
Peer reviewe
Analysis of HIV-1 Fusion Peptide inhibition by synthetic peptides from E1 protein of GB virus C
The aim of this study was to identify proteins that could inhibit the activity of the peptide sequence representing the N-terminal of the surface protein gp41 of HIV, corresponding to the fusion peptide of the virus (HIV-1 FP). To do this we synthesized and studied 58 peptides corresponding to the envelope protein E1 of the hepatitis G virus (GBV-C). Five of the E1 synthetic peptides: NCCAPEDIGFCLEGGCLV (P7), APEDIGFCLEGGCLVALG (P8), FCLEGGCL VALGCTICTD (P10), QAGLAVRPGKSAAQLVGE (P18) and AQLVGELGSLYGPLSVSA (P22) were capable of inhibiting the leakage of vesicular contents caused by HIV-1 FP. A series of experiments were carried out to determine how these E1 peptides interact with HIV-1 FP. Our studies analyzed the interactions with and without the presence of lipid membranes. Isothermal titration calorimetry revealed that the binding of P7, P18 and P22 peptides to HIV-1 FP is strongly endothermic, and that binding is entropy-driven. Gibbs energy for the process indicates a spontaneous binding between E1 peptides and HIV-1 FP. Moreover, confocal microscopy of Giant Unilamellar Vesicles revealed that the disruption of the lipid bilayer by HIV-1 FP alone was inhibited by the presence of any of the five selected peptides. Our results highlight that these E1 synthetic peptides could be involved in preventing the entry of HIV-1 by binding to the HIV-1 FP. Therefore, the continued study into the interaction between GBV-C peptides and HIV-1 FP could lead to the development of new therapeutic agents for the treatment of AIDS
Assessment of oxidative damage to proteins and DNA in urine of newborn infants by a validated UPLC-MS/MS approach
The assessment of oxidative stress is highly relevant in clinical Perinatology as it is associated to adverse outcomes in newborn infants. This study summarizes results from the validation of an Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous quantification of the urinary concentrations of a set of endogenous biomarkers, capable to provide a valid snapshot of the oxidative stress status applicable in human clinical trials, especially in the field of Perinatology. The set of analytes included are phenylalanine (Phe), para-tyrosine (p-Tyr), ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-NO2-tyrosine (3NO 2-Tyr), 3-Cl-tyrosine (3Cl-Tyr), 2′-deoxyguanosine (2dG) and 8-hydroxy-2′-deoxyguanosine (8OHdG). Following the FDA-based guidelines, appropriate levels of accuracy and precision, as well as adequate levels of sensitivity with limits of detection (LODs) in the low nanomolar (nmol/L) range were confirmed after method validation. The validity of the proposed UPLC-MS/MS method was assessed by analysing urine samples from a clinical trial in extremely low birth weight (ELBW) infants randomized to be resuscitated with two different initial inspiratory fractions of oxygen
Nested inversion polymorphisms predispose chromosome 22q11.2 to meiotic rearrangements [RETRACTED]
Inversion polymorphisms between low-copy repeats (LCRs) might predispose chromosomes to meiotic non-allelic homologous recombination (NAHR) events and thus lead to genomic disorders. However, for the 22q11.2 deletion syndrome (22q11.2DS), the most common genomic disorder, no such inversions have been uncovered as of yet. Using fiber-FISH, we demonstrate that parents transmitting the de novo 3 Mb LCR22A–D 22q11.2 deletion, the reciprocal duplication, and the smaller 1.5 Mb LCR22A–B 22q11.2 deletion carry inversions of LCR22B–D or LCR22C–D. Hence, the inversions predispose chromosome 22q11.2 to meiotic rearrangements and increase the individual risk for transmitting rearrangements. Interestingly, the inversions are nested or flanking rather than coinciding with the deletion or duplication sizes. This finding raises the possibility that inversions are a prerequisite not only for 22q11.2 rearrangements but also for all NAHR-mediated genomic disorders
Genetic contributors to risk of schizophrenia in the presence of a 22q11.2 deletion
Schizophrenia occurs in about one in four individuals with 22q11.2 deletion syndrome (22q11.2DS). The aim of this International Brain and Behavior 22q11.2DS Consortium (IBBC) study was to identify genetic factors that contribute to schizophrenia, in addition to the ~20-fold increased risk conveyed by the 22q11.2 deletion. Using whole-genome sequencing data from 519 unrelated individuals with 22q11.2DS, we conducted genome-wide comparisons of common and rare variants between those with schizophrenia and those with no psychotic disorder at age ≥25 years. Available microarray data enabled direct comparison of polygenic risk for schizophrenia between 22q11.2DS and independent population samples with no 22q11.2 deletion, with and without schizophrenia (total n = 35,182). Polygenic risk for schizophrenia within 22q11.2DS was significantly greater for those with schizophrenia (padj = 6.73 × 10−6). Novel reciprocal case–control comparisons between the 22q11.2DS and population-based cohorts showed that polygenic risk score was significantly greater in individuals with psychotic illness, regardless of the presence of the 22q11.2 deletion. Within the 22q11.2DS cohort, results of gene-set analyses showed some support for rare variants affecting synaptic genes. No common or rare variants within the 22q11.2 deletion region were significantly associated with schizophrenia. These findings suggest that in addition to the deletion conferring a greatly increased risk to schizophrenia, the risk is higher when the 22q11.2 deletion and common polygenic risk factors that contribute to schizophrenia in the general population are both present
Congenital Critical Heart Defect Screening in a Health Area of the Community of Valencia (Spain): A Prospective Observational Study
Despite the progress in the fetal echocardiographic detection of congenital critical heart defects and neonatal physical examination, a significant number of newborn infants are discharged and readmitted to the hospital in severe condition due to cardiac failure or collapse. The aim of this study was to assess the incidence of undetected critical congenital heart disease (CCHD) by a pulse oximetry-screening program in the maternity wards of hospitals with Perinatal Services in a specific geographic area. This is a prospective observational study performed in in the health area corresponding to the city of Valencia. Eligible infants were consecutively admitted newborn infants in the maternities of the participating hospitals with negative fetal echocardiography after normal physical examination in the delivery room. All patients were screened following a specific pulse oximetry protocol before discharge. A total of 8856 newborn infants were screened. A total of three babies presented with severe congenital cardiac malformation and two babies presented with early onset sepsis. Sensitivity was 100% and specificity was 99.97%, with a positive predictive value of 60% and negative predictive value of 100%. Pulse oximetry screening programs in the early neonatal period constitute a valuable tool to avoid inadvertent hospital discharge of severe cardiac malformations and the subsequent life-threatening complications derived
Congenital Critical Heart Defect Screening in a Health Area of the Community of Valencia (Spain): A Prospective Observational Study
Despite the progress in the fetal echocardiographic detection of congenital critical heart defects and neonatal physical examination, a significant number of newborn infants are discharged and readmitted to the hospital in severe condition due to cardiac failure or collapse. The aim of this study was to assess the incidence of undetected critical congenital heart disease (CCHD) by a pulse oximetry-screening program in the maternity wards of hospitals with Perinatal Services in a specific geographic area. This is a prospective observational study performed in in the health area corresponding to the city of Valencia. Eligible infants were consecutively admitted newborn infants in the maternities of the participating hospitals with negative fetal echocardiography after normal physical examination in the delivery room. All patients were screened following a specific pulse oximetry protocol before discharge. A total of 8856 newborn infants were screened. A total of three babies presented with severe congenital cardiac malformation and two babies presented with early onset sepsis. Sensitivity was 100% and specificity was 99.97%, with a positive predictive value of 60% and negative predictive value of 100%. Pulse oximetry screening programs in the early neonatal period constitute a valuable tool to avoid inadvertent hospital discharge of severe cardiac malformations and the subsequent life-threatening complications derived
Disculpen las molestias, el machismo mata
illustratorPartimos del supuesto de que la conceptuación de la violencia contra las mujeres está impregnada de conocimientos provenientes, entre otros, de los medios de comunicación, y que estos han de someterse a consideración desde la docencia y la investigación, desvelando las gramáticas visuales, los mitos, las creencias estereotipadas,las tensiones,así como las asimetrías que subyacen a los modelos normativos de género. Para ello es fundamental un análisis directo de estas cuestiones con jóvenes varones y mujeres a través de acciones participativas. El presente libro asociado a un video-ensayo consta de seis capítulos que afrontan la violencia machista para la concienciación social, analizando distintos aspectos de la violencia de genero ejercida sobre las mujeres. Configurado por una serie de seis videos cortos, estos abarcan diferentes temáticas: 1. La violencia simbólica, estructural, psicológica y física contra las mujeres; 2. El feminicidio; 3. La violencia contra las mujeres en los medios de información, comunicación y ocio; 4. La violencia de genero en la prostitución; 5. La discriminación múltiple en las mujeres migrantes; 6. Las relaciones asimétricas de poder: el techo de cristal; 7. Los mitos y falsas creencias sobre la violencia de genero
Disculpen las molestias, el machismo mata
Partimos del supuesto de que la conceptuación de la violencia contra las mujeres está impregnada de conocimientos provenientes, entre otros, de los medios de comunicación, y que estos han de someterse a consideración desde la docencia y la investigación, desvelando las gramáticas visuales, los mitos, las creencias estereotipadas, las tensiones, así como las asimetrías que subyacen a los modelos normativos de género. Para ello es fundamental un análisis directo de estas cuestiones con jóvenes varones y mujeres a través de acciones participativas.
El presente libro asociado a un video-ensayo consta de seis capítulos que afrontan la violencia machista para la concienciación social, analizando distintos aspectos de la violencia de genero ejercida sobre las mujeres. Configurado por una serie de seis videos cortos, estos abarcan diferentes temáticas:
1. La violencia simbólica, estructural, psicológica y física contra las mujeres;
2. El feminicidio;
3. La violencia contra las mujeres en los medios de información, comunicación y ocio;
4. La violencia de genero en la prostitución;
5. La discriminación múltiple en las mujeres migrantes;
6. Las relaciones asimétricas de poder: el techo de cristal;
7. Los mitos y falsas creencias sobre la violencia de genero.Aliaga Espert, JV.; Botella Mestres, M.; Monleón Pradas, EE.; Navarrete Tudela, CL.; Cubells Casares, MD. (2016). Disculpen las molestias, el machismo mata. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/67709EDITORIA