CNS Maturation Process in Children and Adolescents in the Northern Region of the Russian Federation and Its Reflection in the Dynamics of Integral EEG Parameters

Neuroscience and Behavioral Physiology - We present here results from analysis of the formation of brain bioelectrical activity in children and adolescents living in the northern region of Russia...     

Sepsis as a cause and consequence of acute kidney injury: Program to Improve Care in Acute Renal Disease

Purpose  

Sepsis commonly contributes to acute kidney injury (AKI); however, the frequency with which sepsis develops as a complication of AKI and the clinical consequences of this sepsis are unknown. This study examined the incidence of, and outcomes associated with, sepsis developing after AKI.     

Age Dynamics of Evoked Brain Potentials in Involuntary and Voluntary Attention to a Deviant Stimulus in Schoolchildren from the Northern Region

The central mechanisms of involuntary and voluntary regulation of attention in schoolchildren from the northern region were studied using a method based on the P300 wave of evoked brain potentials (the oddball paradigm). Data were compared with results obtained from psychological tests. Differences in the organization of EP were seen in the “passive” and active (counting) perception of deviant stimuli. Three components were identified within the time envelop of the P300 wave, two of which dominated in the frontal and one in the parietal area of the cerebral cortex. The latency of the P300 wave decreased with age in the children, reflecting increased rates of information processing and increases in the volume of operative memory. In passive perception, the statistical relationship characterized by a reduction in P300 latency with age was significant for leads in the central, temporal, parietal, and occipital areas; in active perception, this applied to all areas including the frontal. The most significant changes in P300 parameters were seen in children aged from seven to 12 years, indicating that this period can be regarded as “critical” in the development of learning skills. The roles of the parietal and frontal areas of the cortex in the mechanisms of involuntary and voluntary regulation of attention are discussed, along with the possibility of using the P300 method to identify children with delayed rates of development of voluntary attention in population studies.     

Pro-convulsant actions of theophylline and caffeine in the hippocampus: implications for the management of temporal lobe epilepsy

The pro-convulsant actions of theophylline and caffeine have been investigated using the hippocampal slice preparation and rats administered kainic acid or Metrazol. Both theophylline and caffeine induced the generation of epileptiform activity in the CA3 region of the hippocampal slice with convulsive dose50 (CD50) values of 3 microM respectively. Kainic acid-induced bursting in hippocampal slices was enhanced by theophylline (0.3-30 microM) and caffeine (1-100 microM). Theophylline induced burst firing in response to electrical stimulation in hippocampal area CA3 but not area CA1. Theophylline (50 mg/kg) strongly potentiated the effect of the limbic convulsant kainic acid in vivo whilst a dose of 200 mg/kg was necessary to significantly lower the threshold dose of Metrazol required to induce generalized convulsions. We conclude that alkylxanthines, probably by antagonizing the effect of endogenous adenosine, exert a pro-convulsant action in the hippocampus which preferentially promotes limbic seizures.     

Buspirone antagonizes the expression of conditioned taste aversion in rats

When the parameters of taste aversion conditioning and testing have been appropriately adjusted, benzodiazepines and barbiturates will markedly antagonize the expression of moderate taste aversions in rats. We call this the taste aversion conflict model of anxiety. In the present study, we investigate whether buspirone HCl (buspirone; p.o. and i.p.) is active in the taste aversion conflict model and whether buspirone will also increase unsuppressed saccharin (SACC) intake. We also investigated the effects of imipramine, desipramine, phenelzine sulfate, chlorpromazine, scopolamine and d-amphetamine sulfate in the taste aversion conflict model. To assess the possible effects of buspirone on the GABA-benzodiazepine supramolecular receptor complex, we compared buspirone with certain benzodiazepines, meprobamate and sodium phenobarbital on the antagonism of pentylenetetrazol-induced lethality in mice. Unlike benzodiazepines, meprobamate and phenobarbital, buspirone did not antagonize pentylenetetrazol-induced lethality. However, like those other anxiolytics, buspirone markedly antagonized the expression of conditioned taste aversion. All nonanxiolytic drugs tested had either no effect or very slight effects on the expression of conditioned taste aversion. These results suggest that the taste aversion conflict model is sensitive to novel anxiolytics and that it is selective for drugs clinically effective in the treatment of generalized anxiety disorders in man.     

Diuretics,mortality, and nonrecovery of renal function in acute renal failure

Context  Acute renal failure is associated with high mortality and morbidity. Diuretic agents continue to be used in this setting despite a lack of evidence supporting their benefit. Objective  To determine whether the use of diuretics is associated with adverse or favorable outcomes in critically ill patients with acute renal failure. Design  Cohort study conducted from October 1989 to September 1995. Patients and Setting  A total of 552 patients with acute renal failure in intensive care units at 4 academic medical centers affiliated with the University of California. Patients were categorized by the use of diuretics on the day of nephrology consultation and, in companion analyses, by diuretic use at any time during the first week following consultation. Main Outcome Measures  All-cause hospital mortality, nonrecovery of renal function, and the combined outcome of death or nonrecovery. Results  Diuretics were used in 326 patients (59%) at the time of nephrology consultation. Patients treated with diuretics on or before the day of consultation were older and more likely to have a history of congestive heart failure, nephrotoxic (rather than ischemic or multifactorial) origin of acute renal failure, acute respiratory failure, and lower serum urea nitrogen concentrations. With adjustment for relevant covariates and propensity scores, diuretic use was associated with a significant increase in the risk of death or nonrecovery of renal function (odds ratio, 1.77; 95% confidence interval, 1.14-2.76). The risk was magnified (odds ratio, 3.12; 95% confidence interval, 1.73-5.62) when patients who died within the first week following consultation were excluded. The increased risk was borne largely by patients who were relatively unresponsive to diuretics. Conclusions  The use of diuretics in critically ill patients with acute renal failure was associated with an increased risk of death and nonrecovery of renal function. Although observational data prohibit causal inference, it is unlikely that diuretics afford any material benefit in this clinical setting. In the absence of compelling contradictory data from a randomized, blinded clinical trial, the widespread use of diuretics in critically ill patients with acute renal failure should be discouraged.      

Characteristics of the formation of systems activity in the brain and autonomic functions in children in conditions of the European North (discussion paper)

Results obtained from complex medical-physiological investigations performed during 10 scientific expeditions in the Arkhangel’sk Region in 2003–2005 are presented. The effects of climatological-geographic, biogeochemical, and social conditions of the conditions obtaining in the Far North region of Russia on sexual maturation, formation of the structural-functional organization of the brain, autonomic functions, and immunological and biochemical status of schoolchildren were studied using state-of-the-art neurophysiological methods (computerized electroencephalography, computerized rheoencephalography, computerized electric dipole origin tomography, etc.), psychophysiological and psychometric methods (assessment of the state of cognitive and memory functions, Wechsler intellectual scale), along with biochemical assay of monoamine oxidase (MAO, the key enzyme in adrenergic neurotransmitter metabolism) and the liver enzyme butyrylcholinesterase (BuChE) and physicochemical analysis of the levels of macroelements and trace elements in the body. __________ Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 92, No. 8, pp. 905–929, August, 2006.