Saratov State Medical University

The study assessed DNA damage in cells of various mouse organs in an induced mutagenesis experiment, evaluating the potential modifying effect of Helichrysum arenarium L. extract using the DNA comet assay. The extract did not exhibit genotoxic effects at the tested doses (50, 100, and 200 mg/kg). It reduced the mutagenic effects of both dioxidine and cyclophosphamide at doses of 100 and 200 mg/kg in bone marrow, kidney, spleen, and liver cells, while at 50 mg/kg, the protective effect was observed only in bone marrow and kidney cells. Thus, the Helichrysum arenarium extract demonstrated DNA-protective properties in an experiment on outbred white male mice.

The relevance of this review lies in examining the known mechanisms of sleep initiation, maintenance, and termination; assessing the impact of sleep on systemic physiology; investigating the relationship between circadian rhythm regulation and sleep parameters; and exploring contemporary methods for evaluating sleep characteristics. The review presents current understandings of sleep physiology, characterizing sleep as an active, heterogeneous, and complex process that influences overall organismal physiology. Regulation of sleep–wake cycles involves central nervous system structures as well as humoral factors synthesized both in relation to sleep depth and independently of sleep processes, yet actively modulating them. Articles are cited that elucidate the interplay between sleep–wake cycles, organismal metabolic processes, and the light–dark cycle, manifested as circadian rhythms. It is demonstrated that human populations can be classified into “morning,” “evening,” and “day” chronotypes based on circadian regulation patterns. Data are compiled on associations between chronotype categories and electroencephalographic (EEG) activity features, including sex-specific variations. The article highlights modern trends toward integrating advanced technological solutions into specific research challenges, fostering the development of automated systems for analyzing sleep architecture and potential “special” sleep events using photoplethysmographic waveform data. These systems exhibit high sensitivity and specificity compared to polysomnographic studies.

Parkinson’s disease is known to be closely associated with sleep and breathing disorders. We examined three groups of subjects: 15 apparently healthy patients, 10 patients with obstructive sleep apnea (OSA), and 25 patients with Parkinson’s disease (PD). For each subject, two full-night polysomnography recordings were recorded at intervals of 1–3 days. Polysomnographic electroencephalography (EEG) recordings were analyzed using quantitative recurrence analysis. The ratio of the average recurrence rate for REM sleep stage to other sleep stages was calculated. The PD group showed statistically significant differences ( p < 0.0005 ) with both control and OSA groups. However, statistically significant differences were not found between the control and OSA groups. The main conclusion is that Parkinson’s disease alters the fundamental properties of brain activity during REM sleep, leading to an increased probability of returning EEG values to the previous values in time series.

Background: The high rate of deaths from injuries with uncertain intentions, which are not informative for demographic analysis, leads to a blurring of the real picture of deaths from suicide, murders and accidents, and changes these data. Aim: To analyze the causes of death of the block of injuries with uncertain intentions (Y10-Y34) as one of the components of violent death, affecting the indicators of statistical reporting on mortality from external causes. Materials and methods: A retrospective study of medical death certificates of persons who died a violent death in the Saratov region for the period from 2014 to 2023 was carried out. The causes of death and class codes V01-Y98 of ICD-10 were analysed according to the headings V01-X59 accidents, X60-X84 intentional self-harm, X85-Y09 assault, Y10-Y34 injuries with uncertain intent. Statistical processing of the material was carried out using the Microsoft Office 2010 application package of the Microsoft Excel application. Results: In the structure of violent death from 2014 to 2023, there is a trend of an increase in the share of injuries with uncertain intentions, a decrease in the percentage contribution of suicides and murders. The leading types of death included in block Y10-Y34 are blunt trauma, asphyxia and poisoning, and a significant increase in the proportion of asphyxia and a decrease in blunt trauma were revealed in dynamics. It has been established that the increase in cases in the IUI group occurs mainly due to the movement of falls from height, poisoning and hangings to this block. Conclusions: The study found an increase in the proportion of injuries with uncertain intent in the structure of violent death, mainly due to the transfer to block Y10-Y34 of cases of hanging, falls from heights, blunt force injuries and some poisonings from blocks X60-X84, V01-X59, X85-Y09, which is the reason for the distortion of the indicators of mortality from murders, accidents and suicides.

Currently, the biological activity of peptides participating in the innate immune response is subject to active studies. Despite primarily described antimicrobial effects of these peptides, the current evidence shows that these compounds are multifunctional and participate in the interplay between nervous and immune systems. Some antimicrobial peptides (AMPs), such as α-defensins, are known to bind the melanocortin receptors (MCRs) on adrenal cells and inhibit the activity of adrenocorticotropic hormone (ACTH), thus reducing production of ACTH-mediated corticosteroids. These peptides have been called ‘corticostatins’ due to this effect. Another group of peptides – β-defensins, have also been shown highly-affine binding to MCRs on melanocytes, thus modulating their functions. Previously, our research has provided the evidence that the innate immunity peptides may be involved in performance of stress responses and neuroimmune interactions. However, there is limited information available regarding interactions between AMPs and melanocortin system. The exact nature of interaction between AMPs and MCRs remains unclear, whereas immune cells possess these receptors. Only scarce data exist on how AMPs affects the actions of melanocortins when they bind to these cells. It is also known that AMPs may cause mast cell degranulation, but it has not been established whether MCRs can participate in performance of these effects. The purpose of this work was to study the effect of human α-defensins (HNP-1, HNP-4) on the immunomodulatory effects of α-melanocyte-stimulating hormone (α-MSH). Using ELISA technique, we found that, in the presence of HNP-1 and HNP-4, α-MSH-induced inhibition of cytokine interleukin-1 release by human peripheral blood mononuclear cells in response to lipopolysaccharide in vitro was decreased. The fluorescence microscopy has shown that HNP-1 and HNP-4 abolish the α-MSH-induced suppression of phagocytic activity in cultured human neutrophils. We have also found that MCR-5 antagonist inhibited histamine release from human mast cells of HMC-1 strain induced by α- and β-defensins. Our findings contribute to clarifying the role of innate immune system factors in neuroimmune interactions. Further studies on these effects will help us to uncover their molecular mechanisms.