ISSN Print 2713-2757    ISSN Online 2713-2765
Extreme Medicine

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In addition to damaging the genetic apparatus of the cell, ionizing radiation can cause epigenetic alterations. DNA methylation that plays a vital part in regulation of cellular processes is a common epigenetic modification. DNA methylation ensured by DNA methyltransferases occurs in the CpG-rich sequences. The study was aimed to assess mRNA expression of genes encoding DNA methyltransferases (DNMT1, DNMT3A, DNMT3B) in the chronically exposed individuals who live along the River Techa over a long-term period. A total of 112 people were examined more than 65 years after the beginning of chronic exposure. The average accumulated dose to red bone marrow (RBM) was 782.0 ± 82.3 mGy, and the average accumulated dose to thymus and peripheral lymphoid organs was 93.2 ± 13.6 mGy. The subjects' age at the time of examination was 67.9 ± 0.8 years (54–83 years). The relative mRNA levels for the studied genes were assessed by realtime polymerase chain reaction (real-time PCR). mRNA expression of DNMT1 correlated positively with the dose to RBM (p = 0.04), thymus and peripheral lymphoid organs (p = 0.02), as well as with the dose rate in these organs (p = 0.05, p = 0.04, respectively) during the period of the highest levels of radiation exposure. In individuals exposed in the high dose range (over 1000 mGy) there was a significant increase in the expression of DNMT1 mRNA compared to the comparison group (p = 0.02). The findings may indicate the DNMT1 gene involvement in epigenetic alterations that occur in the chronically exposed people in the long term.
Occupational hearing loss in the civilian flight crew members prevails in the structure of occupational hearing loss. The study was aimed to assess errors made in forensic evaluation of flight personnel with hearing loss. A total of 213 definitive diagnoses of occupational hearing loss established in 2015–2021 were assessed. Expert errors were found in 73% of cases. The most common, typical errors were reported that were evident in 12 cases submitted for forensic evaluation. The main errors were as follows: incorrect assessment of the parameters of noise inside the aircraft cabin, lack of knowledge about the clinical and audiological features of noise-induced hearing loss, incorrect assessment of audiological indicators, underestimation of the role of comorbidities, etc. The findings showed that high proportion of occupational hearing loss in the civilian flight crew members was in large part due to imperfection of expert solutions resulting from the lack of knowledge about the basic criteria of the diagnosis and the relationship between the noise-induced hearing loss and profession. The major requirements for evaluation of the relationship between the noise-induced hearing loss and profession and the issues related to professional suitability set out in the current regulatory documents issued by the Ministry of Health of the Russian Federation and seminal publications were not taken into account. The cornerstones of expert work on the issues of the relationship between the hearing organ disorder and profession in the civilian flight crew members were underestimated. This resulted in unsubstantiated professional unsuitability, disability among working-age people, and economic losses.
Objective diagnostic assessment of the human thought processes is an important issue of modern neurophysiology. The study was aimed to develop a system to analyze visual gnostic processes as a model of higher nervous function. A total of 30 people aged 30–60 having no acute disorders, exacerbations of chronic disorders or significant vision problems were examined. Electroencephalography analysis included EEG artifact removal, clustering and distinguishing specific EEG microctates according to the selected model with subsequent localization of the main source of activity, that had generated the EEG microstate, through the algorithms for solving the inverse EEG problem implemented in the sLORETA software package. When running the visual gnosis test (looking at written symbols), activity was recorded within a larger number of Brodmann areas compared to the state of relaxed wakefulness. Activity was detected within Brodmann areas 18 and 19 (11 and 45%, respectively) responsible for visual perception of images, area 39 being a part of Wernicke's area (6%), and the structures of premotor and prefrontal areas (areas 6–11) (up to 11%) (p < 0.001; Pearson's chi-squared test). Microstates defined when a subject is in a state of relaxed wakefulness or under visual load are not identical. Rather these are gauge derivatives of clustering in the context of used mathematical model. Solving the inverse EEG problem at the final stage of the study makes it possible to define the average sequences of rhythmic activity associated with realization of visual gnostic function.

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Micropolarization was already proved an effective method for restoring impaired brain functions and improving intracerebral processes in the absence of impairments. Combining stimulation methods is a promising approach: a combination of electrode positioning methods can increase the efficacy of the procedures and find application in various fields, from sports through machinery operation to support of operatives of the Ministry of Emergency Situations, etc. This study aimed to assess the effect of a single combined micropolarization procedure on the functional state of the autonomic nervous system and sensorimotor reactions of conventionally healthy individuals. It involved 31 people and relied on the methods enabling evaluation of sensorimotor reactions, cardiorhythmography with spectral analysis of heart rate variability and pupillary reflexes assessment. Volunteers underwent the combined micropolarization procedure once, the duration of the procedure was 40 minutes. The most effective combinations were transspinal plus transcranial micropolarization with positioning in the region of premotor cortex (short-term shift of the autonomic balance towards parasympathetic influence by 48.7%; optimization of the pupil recovery function by 26.4%; increase in interference immunity by 32.2%) and "solar" plus transcranial micropolarization in the area of the temporal zone of cerebral cortex (15.8% increase of the orthostatic test transition period ratio; 6.2% deceleration of the visual-motor reaction).
The clinical spectrum of SARS-CoV-2 infection continues to expand, raising  important fundamental issues regarding the SARS-CoV-2 cellular tropism and pathogenic mechanisms. Liver damage is observed in patients with all forms of  COVID-19, especially severe and critical forms, which could be due to the direct viral damage, immune dysregulation (systemic inflammatory response and cytokine storm), hypoxia-ischemia, drug-induced hepatotoxicity, and concomitant chronic disorders. Liver damage, defined primarily by elevated transaminase levels, is often observed in patients with COVID-19 and correlates with clinical outcomes, including mortality. Diagnostic criteria, pathogenesis, clinical characteristics, treatment, and prognosis of liver injury in COVID-19 should be clarified in further clinical trials. Currently, there is a critical shortage of proven treatment options for patients with COVID-19, resulting in an urgent need to study the multiple organ failure and liver damage pathogenesis in patients with this disease. The review provides information about the pathophysiological mechanisms of the SARS-CoV-2-induced liver damage and the development of liver failure in COVID-19. Information sources were searched in the PubMed database using the keywords “liver damage in COVID-19” and “immune liver damage in COVID-19”.