Convulsión neonatal

Se define el 'estado convulsivo neonatal como una convulsión (cualquiera que sea su forma) que se mantiene de forma continuada o bien que tras desaparecer se repite en un período inferior a 20 minutos a pesar de un tratamiento correcto...

High expression levels of macrophage migration inhibitory factor sustain the innate immune responses of neonates.

The vulnerability to infection of newborns is associated with a limited ability to mount efficient immune responses. High concentrations of adenosine and prostaglandins in the fetal and neonatal circulation hamper the antimicrobial responses of newborn immune cells. However, the existence of mechanisms counterbalancing neonatal immunosuppression has not been investigated. Remarkably, circulating levels of macrophage migration inhibitory factor (MIF), a proinflammatory immunoregulatory cytokine expressed constitutively, were 10-fold higher in newborns than in children and adults. Newborn monocytes expressed high levels of MIF and released MIF upon stimulation with Escherichia coli and group B Streptococcus, the leading pathogens of early-onset neonatal sepsis. Inhibition of MIF activity or MIF expression reduced microbial product-induced phosphorylation of p38 and ERK1/2 mitogen-activated protein kinases and secretion of cytokines. Recombinant MIF used at newborn, but not adult, concentrations counterregulated adenosine and prostaglandin E2-mediated inhibition of ERK1/2 activation and TNF production in newborn monocytes exposed to E. coli. In agreement with the concept that once infection is established high levels of MIF are detrimental to the host, treatment with a small molecule inhibitor of MIF reduced systemic inflammatory response, bacterial proliferation, and mortality of septic newborn mice. Altogether, these data provide a mechanistic explanation for how newborns may cope with an immunosuppressive environment to maintain a certain threshold of innate defenses. However, the same defense mechanisms may be at the expense of the host in conditions of severe infection, suggesting that MIF could represent a potential attractive target for immune-modulating adjunctive therapies for neonatal sepsis.

Reduction in the use of diagnostic tests in infants with risk factors for early-onset neonatal sepsis does not delay antibiotic treatment

BACKGROUND: Despite a low positive predictive value, diagnostic tests such as complete blood count (CBC) and C-reactive protein (CRP) are commonly used to evaluate whether infants with risk factors for early-onset neonatal sepsis (EOS) should be treated with antibiotics. STUDY DESIGN: We investigated the impact of imple- menting a protocol aiming at reducing the number of dia- gnostic tests in infants with risk factors for EOS in order to compare the diagnostic performance of repeated clinical examination with CBC and CRP measurement. The primary outcome was the time between birth and the first dose of antibiotics in infants treated for suspected EOS. RESULTS: Among the 11,503 infants born at 35 weeks during the study period, 222 were treated with antibiotics for suspected EOS. The proportion of infants receiving an- tibiotics for suspected EOS was 2.1% and 1.7% before and after the change of protocol (p = 0.09). Reduction of dia- gnostic tests was associated with earlier antibiotic treat- ment in infants treated for suspected EOS (hazard ratio 1.58; 95% confidence interval [CI] 1.20-2.07; p <0.001), and in infants with neonatal infection (hazard ratio 2.20; 95% CI 1.19-4.06; p = 0.01). There was no difference in the duration of hospital stay nor in the proportion of infants requiring respiratory or cardiovascular support before and after the change of protocol. CONCLUSION: Reduction of diagnostic tests such as CBC and CRP does not delay initiation of antibiotic treat- ment in infants with suspected EOS. The importance of clinical examination in infants with risk factors for EOS should be emphasised.

Measuring the effects through time of the influence of visuomotor and visuotactile synchronous stimulation on a virtual body ownership illusion

Previous studies have examined the experience of owning a virtual surrogate body or body part through specific combinations of cross-modal multisensory stimulation. Both visuomotor (VM) and visuotactile (VT) synchronous stimulation have been shown to be important for inducing a body ownership illusion, each tested separately or both in combination. In this study we compared the relative importance of these two cross-modal correlations, when both are provided in the same immersive virtual reality setup and the same experiment. We systematically manipulated VT and VM contingencies in order to assess their relative role and mutual interaction. Moreover, we present a new method for measuring the induced body ownership illusion through time, by recording reports of breaks in the illusion of ownership ("breaks") throughout the experimental phase. The balance of the evidence, from both questionnaires and analysis of the breaks, suggests that while VM synchronous stimulation contributes the greatest to the attainment of the illusion, a disruption of either (through asynchronous stimulation) contributes equally to the probability of a break in the illusion.

Exploring Brain Inhibition and Facilitation by Transcranial Magnetic Stimulation

Background and Question Paired-pulse TMS (Transcranial Magnetic Stimulation) paradigms allow explore motor cortex physiology. The Triple Stimulation Technique (TST) improves conventional TMS in quantifying cortico-spinal conduction. The objective of our study was to compare both methods in paired-pulse paradigms of inhibition and of facilitation. Method We investigated paired pulse paradigms of 2 ms (short intra-cortical inhibition) and of 10 ms intervals (intra cortical facilitation) in a randomized order in 22 healthy subjects applying conventional TMS and the TST protocol. Results Paired-pulse paradigms by both TMS and the TST yielded comparable results of short intra- cortical inhibition and intra cortical facilitation. However, the coefficient of variation was significantly smaller for SICI paradigm using TST. Conclusion These results suggest no greater sensitivity of the TST for quantifying inhibition and facilitation. The utility of TST to better quantify the individual amount of inhibition in SICI paradigms and its clinical utility need further studies.

Neuroprotection by selective neuronal deletion of Atg7 in neonatal brain injury.

Perinatal asphyxia induces neuronal cell death and brain injury, and is often associated with irreversible neurological deficits in children. There is an urgent need to elucidate the neuronal death mechanisms occurring after neonatal hypoxia-ischemia (HI). We here investigated the selective neuronal deletion of the Atg7 (autophagy related 7) gene on neuronal cell death and brain injury in a mouse model of severe neonatal hypoxia-ischemia. Neuronal deletion of Atg7 prevented HI-induced autophagy, resulted in 42% decrease of tissue loss compared to wild-type mice after the insult, and reduced cell death in multiple brain regions, including apoptosis, as shown by decreased caspase-dependent and -independent cell death. Moreover, we investigated the lentiform nucleus of human newborns who died after severe perinatal asphyxia and found increased neuronal autophagy after severe hypoxic-ischemic encephalopathy compared to control uninjured brains, as indicated by the numbers of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3)-, LAMP1 (lysosomal-associated membrane protein 1)-, and CTSD (cathepsin D)-positive cells. These findings reveal that selective neuronal deletion of Atg7 is strongly protective against neuronal death and overall brain injury occurring after HI and suggest that inhibition of HI-enhanced autophagy should be considered as a potential therapeutic target for the treatment of human newborns developing severe hypoxic-ischemic encephalopathy.

Role of Aeromonas hydrophila flagella glycosylation in adhesion to Hep-2 cells, biofilm formation and immune stimulation.

Polar flagellin proteins from Aeromonas hydrophila strain AH-3 (serotype O34) were found to be O-glycosylated with a heterogeneous heptasaccharide glycan. Two mutants with altered (light and strong) polar flagella glycosylation still able to produce flagella were previously obtained, as well as mutants lacking the O34-antigen lipopolysaccharide (LPS) but with unaltered polar flagella glycosylation. We compared these mutants, altogether with the wild type strain, in different studies to conclude that polar flagella glycosylation is extremely important for A. hydrophila adhesion to Hep-2 cells and biofilm formation. Furthermore, the polar flagella glycosylation is an important factor for the immune stimulation of IL-8 production via toll receptor 5 (TLR5).

Circulating progenitor cells during exercise, muscle electro-stimulation and intermittent hypobaric hypoxia in patients with traumatic brain injury. A pilot study

BACKGROUND: Circulating progenitor cells (CPC) treatments may have great potential for the recovery of neurons and brain function. OBJECTIVE: To increase and maintain CPC with a program of exercise, muscle electro-stimulation (ME) and/or intermittent-hypobaric-hypoxia (IHH), and also to study the possible improvement in physical or psychological functioning of participants with Traumatic Brain Injury (TBI). METHODS: Twenty-one participants. Four groups: exercise and ME group (EEG), cycling group (CyG), IHH and ME group (HEG) and control group (CG). Psychological and physical stress tests were carried out. CPC were measured in blood several times during the protocol. RESULTS: Psychological tests did not change. In the physical stress tests the VO2 uptake increased in the EEG and the CyG, and the maximal tolerated workload increased in the HEG. CPC levels increased in the last three weeks in EEG, but not in CyG, CG and HEG. CONCLUSIONS: CPC levels increased in the last three weeks of the EEG program, but not in the other groups and we did not detect performed psychological test changes in any group. The detected aerobic capacity or workload improvement must be beneficial for the patients who have suffered TBI, but exercise type and the mechanisms involved are not clear.

Levetiracetam versus Phenobarbital. Effects in the neurodevelopment in newborns treated for neonatal seizures: a clinical trial

Purpose: To analyze if the use of Phenobarbital compared with Levetiracetam, it’s associated with more neurodevelopmental problems in newborns treated for neonatal seizures. As a secondary objective identify which are the most affected areas of the neurodevelopment: cognition, socio-­‐emotional, motor or language skills.Design: A 5 years long clinical trial administering, with double-­‐blind and a randomized distribution of the sample, Phenobarbital or Levetiracetam for the management of neonatal seizures

Noradrenergic stimulation enhances human action monitoring

Noradrenergic neurotransmission has been associated with the modulation of higher cognitive functions mediated by the prefrontal cortex. In the present study, the impact of noradrenergic stimulation on the human action-monitoring system, as indexed by eventrelated brain potentials, was examined. After the administration of a placebo or the selective 2 -adrenoceptor antagonist yohimbine, which stimulates firing in the locus ceruleus and noradrenaline release, electroencephalograpic recordings were obtained from healthy volunteers performing a letter flanker task. Yohimbine led to an increase in the amplitude of the error-related negativity in conjunction with a significant reduction of action errors. Reaction times were unchanged, and the drug did not modify the N2 in congruent versus incongruent trials, a measure of preresponse conflict, or posterror adjustments as measured by posterror slowing of reaction time. The present findings suggest that the locus ceruleusnoradrenaline system exerts a rather specific effect on human action monitoring.

Counteracting incentive sensitization in severe alcohol dependence using deep brain stimulation of the nucleus accumbens: clinical and basic science aspects

The ventral striatum / nucleus accumbens has been implicated in the craving for drugs and alcohol which is a major reason for relapse of addicted people. Craving might be induced by drug-related cues. This suggests that disruption of craving-related neural activity in the nucleus accumbens may significantly reduce craving in alcohol-dependent patients. Here we report on preliminary clinical and neurophysiological evidence in three male patients who were treated with high frequency deep brain stimulation of the nucleus accumbens bilaterally. All three had been alcohol dependent for many years, unable to abstain from drinking, and had experienced repeated relapses prior to the stimulation. After the operation, craving was greatly reduced and all three patients were able to abstain from drinking for extended periods of time. Immediately after the operation but prior to connection of the stimulation electrodes to the stimulator, local field potentials were obtained from the externalized cables in two patients while they performed cognitive tasks addressing action monitoring and incentive salience of drug related cues. LFPs in the action monitoring task provided further evidence for a role of the nucleus accumbens in goal-directed behaviors. Importantly, alcohol related cue stimuli in the incentive salience task modulated LFPs even though these cues were presented outside of the attentional focus. This implies that cue-related craving involves the nucleus accumbens and is highly automatic.

Prevención de la infección neonatal precoz por estreptococo del grupo B

El estreptococo del grupo B (EGB) constituye la principal causa de morbimortalidad neonatal y de morbilidad materna durante el embarazo y el posparto. Coloniza el aparato digestivo y el genitourinario en un 10-30% de las gestantes, con una tasa de transmisión vertical del 50%. De entre los recién nacidos colonizados, un 1-2% desarrollará una sepsis grave precoz. Se ha realizado una revisión bibliográfica con el objetivo de conocer las estrategias de prevención de la infección neonatal por EGB. Los resultados ponen de manifiesto que las recomendaciones para su prevención consisten en el cribado universal prenatal de colonización por EGB mediante cultivo vaginorrectal a las 35-37 semanas, y la administración de profilaxis antibiótica intraparto a todas las embarazadas portadoras.

Prevención de la infección neonatal precoz por estreptococo del grupo B

El estreptococo del grupo B (EGB) constituye la principal causa de morbimortalidad neonatal y de morbilidad materna durante el embarazo y el posparto. Coloniza el aparato digestivo y el genitourinario en un 10-30% de las gestantes, con una tasa de transmisión vertical del 50%. De entre los recién nacidos colonizados, un 1-2% desarrollará una sepsis grave precoz. Se ha realizado una revisión bibliográfica con el objetivo de conocer las estrategias de prevención de la infección neonatal por EGB. Los resultados ponen de manifiesto que las recomendaciones para su prevención consisten en el cribado universal prenatal de colonización por EGB mediante cultivo vaginorrectal a las 35-37 semanas, y la administración de profilaxis antibiótica intraparto a todas las embarazadas portadoras.

Fatores preditivos de complicações graves em cirurgia neonatal

OBJETIVO: investigar a incidência e gravidade das complicações pós-operatórias precoces e identificar fatores de risco para o seu desenvolvimento em recém-nascidos submetidos ao tratamento cirúrgico, sob anestesia geral. MÉTODOS: análise retrospectiva dos dados de 437 neonatos com doença crítica submetidos à cirurgia neonatal num centro cirúrgico pediátrico terciário, entre janeiro de 2000 e dezembro de 2010. A gravidade das complicações ocorridas nos primeiros 30 dias de pós-operatório foi classificada utilizando o sistema de Clavien-Dindo para complicações cirúrgicas, sendo considerados graves os graus III a V. Por análise estatística uni e multivariada avaliaram-se variáveis pré e intraoperatórias com potencial preditivo de complicações pós-operatórias graves. RESULTADOS: a incidência de, pelo menos, uma complicação grave foi 23%, com uma mediana de uma complicação por paciente 1:3. Ao todo, ocorreram 121 complicações graves. Destas, 86 necessitaram de intervenção cirúrgica, endoscópica ou radiológica (grau III), 25 puseram em risco a vida, com disfunção uni ou multi-órgão (grau IV) e dez resultaram na morte do paciente (grau V). As principais complicações foram técnicas (25%), gastrointestinais (22%) e respiratórias (21%). Foram identificados quatro fatores de risco independentes para complicações pós-operatórias graves: reoperação, operação por hérnia diafragmática congênita, prematuridade menor que 32 semanas de idade gestacional e cirurgia abdominal. CONCLUSÃO: a incidência de complicações pós-operatórias graves após cirurgias neonatais, sob anestesia geral, permaneceu elevada. As condições consideradas fatores de risco independentes para complicações graves após a cirurgia neonatal podem ajudar a definir o prognóstico pós-operatório em neonatos com doença cirúrgica e orientar as intervenções para melhoria de resultados.