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Pulp diseases treatment may lead to complications, such as the development of apical periodontitis registered with the help of X-ray examination. At the same time, a dentist might provide endodontic treatment associated with apical periodontitis in case there are relevant X-ray changes. In both cases, the periapical status follow-up is required for causality assessment. CBCT data of 2915 endodontically treated teeth were studied assessing the distance from the X-ray root apex to the root filling, as well as assessing the periapical status and tracing the relation between those. It is least probable to detect periapical changes if the length of the root canal filling is 0-1 mm from the X-ray apex, more probable within the length of 1-2 mm, and most probable within the level of over 1 mm and 2 mm, correspondingly. An individual approach excludes the strategy of ‘indication — contra-indication’ related to the length of the root canal filling showing no ground to assess it as a success criterion for endodontic treatment or as an indication for retreatment regardless of the clinical case. In many situations, if there are no clinical signs of unsuccessful endodontic treatment, the periapical tissues follow-up strategy is well-grounded.

In probabilistic conditions, people choose low-payoff alternatives on some trials, thus failing to maximize their payoffs. We suggest that such behavior implicates exploration of task rules by choosing risky options instead of exploiting more rewarding alternatives. We hypothesized that exploration would affect brain responses to feedback. Further, a shift to exploration develops gradually and, therefore, a decision to make an exploratory choice may be observed on trials preceding risky choices. We investigated beta power (16–30 Hz) in the magnetoencephalographic data from 62 healthy participants performing a two-choice probabilistic gambling with monetary gains and losses. The effects were found at 600–800 ms after feedback onset in frontal, central and occipital brain regions. On trials preceding risky choices we identified a decrease in beta power which implies a change in decision-making strategy and a shift towards cognitive flexibility and exploration. An increase in beta power during risky decisions indicates that reward learning mechanisms are implicated. Increases in beta power following losses in risky choices indicates at the process of updating the internal representation of the task. In summary, current findings reveal that the outcomes of exploratory trials are processed differentially, while there is no evidence of such processing on exploitatory trials. This corroborates the hypothesis that exploratory choices represent active probing into the surmised task rules. Current findings also suggest that the processing of outcomes preceding the exploratory trials is altered in such a way that subjects override their intention to use the utility model and reset their behavioral strategy.

Cognitive status and EEG in the theta, alpha, and beta ranges were studied using cluster analysis by discrete optimization in patients with cardiovascular disease in the preoperative period of coronary artery bypass grafting. The cognitive status was measured by Mini-Mental State Examination (MMSE) scale, and an integral indicator of cognitive status (IICS) formed on the basis of complex testing the indices of visual-motor responses, attention, and memory. The new method of clustering the EEG power and the cognitive status made it possible to distinguish groups of patients differenced by cognitive reserves. The IICS better differentiates groups than MMSE. The factors of age and education were decisive only in specific groups. The clusters characterized by the most represented cognitive reserves according to the higher both MMSE and IICS indicators included less pronounced activation of the cortex according to more power of the theta, alpha, and less beta rhythm. Patients with supposedly minimal reserves are differed by a low level of cognitive status, as well as education level together with higher activation state of the cortex. The third type of clusters was distinguished by an unstable composition due to the variability of EEG indicators in it, mostly cortical activity at the alpha1 frequencies. The EEG neurophysiological approach, together with cognitive screening and proposed clustering analysis, could be helpful in understanding mechanisms of cognitive reserves and identify the risk factors of postoperative cognitive dysfunction in patients with brain cardiovascular damage.

The extracellular matrix plays an important role in brain function. Recent findings suggest that disruption of hyaluronan-based extracellular matrix can cause seizure-like activity (Vedunova et al., 2013). Epilepsy can be characterized by an excessive influx of Ca2+ ions through (Ca2+) – permeable AMPA receptors, which may, in certain circumstances, contribute to seizures. Ca2+ – permeability of these receptors is dependent on RNA-editing of pre-mRNA transcript of GluA2 subunit at the Q/R site. Regulation of this process is carried out by a special nuclear enzyme, ADAR2 (Adenosine Deaminase Acting on RNA-2). Thus, the study of the principle of operation of this enzyme can contribute to understanding the mechanism of epileptogenesis.