Search

Purpose Acute onset supraventricular arrhythmias can contribute to haemodynamic compromise in septic shock. Both amiodarone and propafenone are available interventions, but their clinical effects have not yet been directly compared. Methods In this two-centre, prospective controlled parallel group double blind trial we recruited 209 septic shock patients with new-onset arrhythmia and a left ventricular ejection fraction above 35%. The patients were randomised in a 1:1 ratio to receive either intravenous propafenone (70 mg bolus followed by 400-840 mg/24 h) or amiodarone (300 mg bolus followed by 600-1800 mg/24 h). The primary outcomes were the proportion of patients who had sinus rhythm 24 h after the start of the infusion, time to restoration of the first sinus rhythm and the proportion of patients with arrhythmia recurrence. Results Out of 209 randomized patients, 200 (96%) received the study drug. After 24 h, 77 (72.8%) and 71 (67.3%) were in sinus rhythm (p = 0.4), restored after a median of 3.7 h (95% CI 2.3-6.8) and 7.3 h (95% CI 5-11), p = 0.02, with propafenone and amiodarone, respectively. The arrhythmia recurred in 54 (52%) patients treated with propafenone and in 80 (76%) with amiodarone, p < 0.001. Patients with a dilated left atrium had better rhythm control with amiodarone (6.4 h (95% CI 3.5; 14.1) until cardioversion vs 18 h (95% CI 2.8; 24.7) in propafenone, p = 0.05). Conclusion Propafenone does not provide better rhythm control at 24 h yet offers faster cardioversion with fewer arrhythmia recurrences than with amiodarone, especially in patients with a non-dilated left atrium. No differences between propafenone and amiodarone on the prespecified short- and long-term outcomes were observed., Author(s): Martin Balik [sup.1], Michal Maly [sup.1], Tomas Brozek [sup.1], Jan Rulisek [sup.1], Michal Porizka [sup.1], Robert Sachl [sup.1], Michal Otahal [sup.1], Petr Brestovansky [sup.1], Eva Svobodova [sup.1], Marek Flaksa [...]

Today's most common firewalls are mostly rule-based. Their knowledge consists of a set of rules upon which they process received packets. They cannot do anything they have not been explicitly configured to do. This makes the system more straightforward to set up, but less flexible and less adaptive to changing circumstances. We will investigate a network firewall whose rule-base we will try to model using an artificial neural network, more specifically using a multi-layer perceptron (MLP) trained by the back-propagation algorithm. The training data are acquired from the network and we consider two possible scenarios. In Scenario 1, the user has no firewall available and the policy is deduced from the existing traffic in the network which is considered to be legitimate. In Scenario 2, the learning module is placed behind the existing firewall (or firewalls) in order to learn their behavior. In both cases, all traffic, which is recorded, contains only positive examples; however, a direct training of a MLP from a set of positive examples is impossible. We solved this problem using a synthetic generation of negative examples which led to successful learning. [ABSTRACT FROM AUTHOR]

Multiple molecular targets have been identified to mediate membrane-delimited and nongenomic effects of natural and synthetic steroids, but the influence of steroid metabolism on neuroactive steroid signaling is not well understood. To begin to address this question, we set out to identify major metabolites of a neuroprotective synthetic steroid 20-oxo-5β-pregnan-3α-yl l-glutamyl 1-ester (pregnanolone glutamate, PAG) and characterize their effects on GABA A and NMDA receptors (GABARs, NMDARs) and their influence on zebrafish behavior. Gas chromatography-mass spectrometry was used to assess concentrations of PAG and its metabolites in the hippocampal tissue of juvenile rats following intraperitoneal PAG injection. PAG is metabolized in the peripheral organs and nervous tissue to 20-oxo-17α-hydroxy-5β-pregnan-3α-yl l-glutamyl 1-ester (17-hydroxypregnanolone glutamate, 17-OH-PAG), 3α-hydroxy-5β-pregnan-20-one (pregnanolone, PA), and 3α,17α-dihydroxy-5β-pregnan-20-one (17-hydroxypregnanolone, 17-OH-PA). Patch-clamp electrophysiology experiments in cultured hippocampal neurons demonstrate that PA and 17-OH-PA are potent positive modulators of GABARs, while PAG and 17-OH-PA have a moderate inhibitory effect at NMDARs. PAG, 17-OH-PA, and PA diminished the locomotor activity of zebrafish larvae in a dose-dependent manner. Our results show that PAG and its metabolites are potent modulators of neurotransmitter receptors with behavioral consequences and indicate that neurosteroid-based ligands may have therapeutic potential.