Probabilistic graphical model identifies clusters of EEG patterns in recordings from neonates.

Objectives: In this paper we introduce a novel method for the evaluation of neonatal brain function via multivariate EEG (electroencephalography) signal processing and embedding into a probabilistic graph, the so called Chow-Liu tree.

Methods: Using 28 EEG recordings of preterm and term neonate infants the complex features of the EEG signals were constructed in the form of a Chow-Liu tree. The trees were embedded into a 3 dimensional Euclidean space.

[Autoregulation of cerebral blood flow in condition of experimental hepatic encephalopathy].

The linear interrelation between Systemic Arterial Blood Pressure and local Cerebral Blood Flow has been shown in experiments on rats with induced experimental hepatic encephalopathy. This is evidence of complete malfunctioning of the mechanism of Cerebral Blood Flow Autoregulation. Quantitative comparison of local Cerebral Blood Flow intensity in control and experimental (Hepatic Encephalopathy) animals has shown significant increase of the basic level of cerebral blood flow in rats with induced Hepatic Encephalopathy (p<0,05).

On the consistency of the blocked neural network estimator in time series analysis.

We describe a nonlinear regression problem, where the regression functions have an additive structure and the dependent variable is a one-dimensional time series. Multivariate time series with unknown time delay operators are used as independent variables. By fitting a feedforward neural network with block structure to the data, we estimated the additive regression function and, parallel to this, the time lags.

[Changes in emotional state and learning process disorders in rats with experimental hepatic encephalopathy].

Animal models of liver failure are widely used for research of morphological and functional changes and pathogenetic mechanisms of hepatic encephalopathy. Changes in learning process and emotional state of rats, which were administered intraperitoneally (Phenobarbiton 40 mg/kg/day) for five days and then subcutaneously (Acetaminophen 1000 mg/kg) are described. Behaviour of rats was studied in the "open field".

[The models of hepatic insufficiency and encephalopathy in animals].

The majority of the investigation methods of biochemical, morphological and metabolic disorders in hepatic insufficiency and encephalopathy occurrence are inadequate in use in clinical conditions because their invasiveness frequently creates dangerous situations to the patient life and health. That's why, to characterize the mechanisms, constituting the hepatic and cerebral damages base, for testing of a new medicinal preparations, aprobation of a new theoretical and clinical hypotheses, the models of an acute and chronic hepatic insufficiency are applied on the animals, permitting to unify the age, genetic peculiarities and physiological parameters of the individuals involved in experiments, the pathology character, its severity and longevity. Homogeneity of these indexes permits to estimate molecular, structural and functional disorders, laying in the base of pathological process.