Vadim A. Kashuro

Glioblastoma (GBM) is one of the most malignant and common human brain tumors. This tumor contains glioblastoma stem cells (GSCs), which drive tumor growth, progression, and metastasis even after surgical resection, radiation, and chemotherapy. Physiological changes within the body facilitate the adaptation, maintenance, survival, and proliferation of GBM cells. Underlying this cellular plasticity is the asymmetric division of GBM cells, which gives rise to diverse cancer cell types. Consequently, the issue of GBM plasticity is crucial for understanding tumor biology and developing effective therapeutic strategies. This review focuses on GBM heterogeneity, associated markers, microRNAs, long non-coding RNAs, signaling cascades (kinases, transcription factors), genes, and transitions between distinct cellular phenotypes. It examines the expression and regulation of GSC markers across various cellular states are influenced by cell cycle phases and the transition from a proneural (PN) to a mesenchymal phenotype (MES)— proneural-mesenchymal transition (PMT) which are associated with changes in cellular activity. The PN and MES of GBM cells are represented as a dynamic continuum of transitional states underlying the processes of self-renewal, proliferation, invasion migration, therapy resistance, and differentiation. Further research is needed to elucidate the molecular mechanisms of GBM cellular plasticity involved in angiogenesis, metastasis, and immunosuppression of the tumor microenvironment.

The aim of the study is to propose ways to optimize gastric lavage from food. Materials and methods. А series of simulations of gastric lavage through a gastric tube with a diameter of 1 cm from mashed potatoes, oatmeal and rice porridge using a Janet syringe and tap water with temperatures of 15 ^° C, 20 ^° C, 37 ^° C and 45 ^° C. Results. Regardless of the water temperature, it took the shortest time to wash the stomach model from mashed potatoes: Me 7.6 (Q1–Q3: 6.3–10.8) minutes. The evacuation time of oatmeal porridge was: Me 17.5 (Q1–Q3: 14.1–22.8). When using water with a temperature of 15 ^° C and 20 ^° C, it was not possible to remove rice porridge from the stomach model within 60 minutes, in other cases it took the longest time: Me 19.8 (Q1–Q3: 18.8–21.8) minutes. A decrease in the gastric lavage time was revealed with an increase in water temperature (pConclusion. An increase in the effectiveness of gastric lavage can be achieved by increasing the temperature of the water used (p<0.05). The developed original modification of the gastric lavage probe also made it possible to reduce the time of evacuation of stomach contents (p<0.05). After testing in experiments on laboratory animals and clinical studies, the data obtained can change approaches to gastric lavage in an urgent situation.

Background. Medulloblastoma (MB) prognosis and response to therapy depend largely on genetic changes in tumor cells. Many genes and chromosomal abnormalities have been identified as prognostic factors, including amplification of MYC oncogenes, gains in 1q and 17q, deletions in 10q and 21p, or isochromosomes 17 (i(17)(q10)). The frequency of these abnormalities varies greatly between ethnic populations, but the frequency of specific abnormalities, such as MYCC and MYCN amplification, 17q gain, and deletions, in the Russian population is unknown. Objective: The aim is to study the frequency of MYCC and MYCN amplifications, 17q gain, and 17p deletion and determine their prognostic value in Russian patients with MB. Methods. This study was performed on MB cells obtained from 18 patients (12 boys and 6 girls, aged between 3 months and 17 years, with a median age of 6.5 years). Determination of cytogenetic aberrations was carried out using FISH assays with MYCC-SO, MYCN-SO, and MYCN-SG/cen2 probes, as well as cen7/p53 dual color probes and PML/RARα dual color probes (Abbott Molecular, USA). One-way ANOVA and Fisher’s F-test were used to compare the two groups. The differences were considered significant when p < 0.05. Results. In 77.7% of patients (14/18), the classical type of MB was present; in 16.7% (3/18), desmoplastic type; and in 5.6% (1/18), nodular desmoplasic types of neoplasms. Amplification of MYC genes was detected in 22.2% of Russian patients (n = 4 out of 18). Patients with MYC amplification had the worst overall survival (OS: 0% vs. 68%, p = 0.0004). Changes on the 17th chromosome were found in 58.3% of patients. Deletion of 17p occurred in 23.1%, and gain of 17q occurred in 46.2%. There were no significant differences in OS, clinical signs, or the presence of additional 17q material or 17p deletion among patients with MB. Conclusions: Amplification of the MYC gene is a predictor of poor overall survival to therapy and a high risk of metastatic relapse. This allows us to more accurately stratify patients into risk groups in order to determine the intensity and duration of therapy.

Introduction. Mercury poisoning has a cumulative effect. Mercury gradually accumulates in tissues and organs, which negatively affects the functions of all body systems, especially the brain. The aim of this study was to investigate the neuropeptides content in the blood plasma of Wistar rats after subchronic low-dose mercury acetate poisoning. Material and methods. During the study, rats was intragastrically administered mercury acetate at a dose of 4 mg/kg for 30 days. On days 30 and 44, the blood plasma of rats was tested for the levels of calcium-binding protein (S100), glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), pigment epithelial-derived factor (PEDF), myelin basic protein (MBP). Results. The concentration of S100 protein in the blood plasma of the experimental group of rats decreased by 43,9%, and the concentration of MBP increased by 172,6%. Fourteen days after the end of the toxicant administration, the concentration of protein S100 in the blood plasma of poisoned animals was significantly lower by 132,7% compared to the control group. The content of MBP increased by 59,4% and neuron-specific enolase increased by 44,6%, the concentration of neuropeptides PEDF and GFAP changed insignificantly. Conclusions. The results obtained demonstrate that even low concentrations of mercury acetate, entering the body for a long time, affect the concentration of neuropeptides in blood plasma, which indicates negative changes in the central nervous system of rats.

На протяжении жизни человек подвергается интенсивному воздействию различных веществ, используемых в промышленности, красителей, сельскохозяйственных ядохимикатов, растворителей, моющих средств, пищевых добавок. Широко и зачастую неоправданно используются лекарственные препараты. Бόльшая часть этих веществ, воздействуя на организм, может индуцировать не только активационный ответ иммунной системы, но и оказывать депрессивное влияние на иммунитет в целом. Таким образом, иммунотоксиканты — это химические соединения, относящиеся к ксенобиотикам, значимо изменяющие тот или иной параметр иммунореактивности или же одну или несколько иммунных функций, что оказывает неблагоприятный эффект на организм и может клинически проявиться синдромами иммунопатологии. В организме человека иммунотоксиканты, как и любые другие ксенобиотики, подвергаются различным биохимическим превращениям с целью их обезвреживания и выведения из организма. Биотрансформация и метаболизм иммунотоксикантов является сложным и многостадийным процессом. Данный обзор посвящен первой фазе биотрансформации ксенобиотиков, которая направлена на образование гид­рофильных соединений, вступающих в другие метаболические превращения и выводящихся из организма экскреторными органами. Подробно описаны ферментные системы микросомального и немикросомального происхождения, осуществляющие реакции первой фазы биотрансформации. Обобщены известные данные по локализации различных изоформ ферментов и их субстратной специфичности. Представлены некоторые реактивные продукты первой фазы биотрансформации ксенобиотиков, которые могут быть токсичны для клеток, так как многие из них являются свободными радикалами. Некоторые реакционноспособные метаболиты способны к ковалентному связыванию с макромолекулами организма — аутоантигенами, что модифицирует их антигенную специфичность, создавая условия для аутосенсибилизации и включения классических механизмов иммунореактивности. Другие же способны, активируя клетки естественной резистентности, вовлекать в ответ на эти соединения неспецифические (доиммунные) механизмы иммунореактивности, в частности активировать механизмы воспалительного ответа, включая его гиперсенсибилизационный (аллергический) тип. Таким образом, нарушение реакций первой фазы биотрансформации ксенобиотиков является основным фактором развития многих заболеваний химического генеза, включая некоторые нозологические формы аутоиммунной патологии. Throughout life, a person is exposed to intense exposure to various substances used in industry, dyes, agricultural pesticides, solvents, detergents, and food additives. Medicines are widely and often unjustifiably used. A large proportion of these substances, acting on the organism, can induce not only an activation response of the immune system, but also have a depressive effect on the immune system as a whole. Thus, immunotoxicants are chemical compounds related to xenobiotics that significantly change one or another parameter of immunoreactivity or one or more immune functions, which has an adverse effect on the body and can be clinically manifested by immunopathology syndromes. In the human organism, immunotoxicants, like any other xenobiotics, undergo various biochemical transformations in order to neutralize them and remove them from the organism. Biotransformation and metabolism of immunotoxicants is a complex and multistage process. This part of the review is devoted to the first stage of biotransformation of xenobiotics, which is aimed at the formation of hydrophilic compounds that enter into other metabolic transformations and are excreted from the body by excretory organs. Enzyme systems of microsomal and non-microsomal origin that carry out biotransformation phase 1 reactions are described in detail. The known data on the localization of various isoforms of enzymes and their substrate specificity are summarized....

Purpose of the study. To study the effect of sequential release of peptide extracts (PEE) from the pineal gland and pituitary gland of reindeer (Rangifer tarandus) on endogenous regulatory proteins (hypoxia-inducible factor 1 alpha (HIF1α), peroxisome proliferatoractivated receptor gamma (PPARγ), soluble phosphoenolpyruvate carboxykinase 1 (PEPCK) and melatonin in the blood serum of male rats under conditions of experimental light desynchronosis.Materials and methods. Modeling of light desynchronization was carried out on two-month laboratory white outbred male rats weighing 180 ± 20 g in the number of 144 individuals. The animals were divided by the method of randomization into three main groups: 1st group represented the control, in which the normal lighting regimen was modeled (LED lighting 500 lux day/night 12/12); the 2nd group was kept in the regimen of constant illumination; the third group was kept in a regimen of constant darkness. The formation of light desynchronization was carried out for 30 days. During the first 14 days of the formation of light desynchronosis, the rats were intranasally being administered with the test substances. After 30 days from the beginning of the experiment, the rats were euthanized for the collection of biological material. The blood serum HIF1α, PPARγ, PCK1 and melatonin levels of laboratory animals were analyzed by the enzyme immunoassay method (EIA).Results. The use of PEE in two doses during light deprivation has reduced the concentration of HIF1α in the blood serum, indicating improved oxygen utilization in the tissues of experimental animals. PEE in two doses has caused a sharp increase in the concentration of the transcription factor in blood serum PPARγ, which promotes the initiation of processes regulating the exchange of lipids and carbohydrates in adipose tissue. The application of peptide extracts in two doses has revealed a decrease in the activity of PCK1 under constant illumination. With constant exposure to PEE in doses 100 mg/kg, it promotes an increase in the concentration of melatonin in the blood serum, approximately equal to the level of the control group.Conclusion. The study revealed the chronobiotic effects of PEE on the concentration of regulatory proteins and melatonin in the blood serum of male rats in the conditions of light desynchronization. It should also be noted that these effects differ from the known effects of the delta-sleep inducing peptide, which may be due to a different mechanism of molecular action.

Background: Glioblastoma multiforme (GBM) is a very malignant brain tumor. GBM exhibits cellular and molecular heterogeneity that can be exploited to improve patient outcomes by individually tailoring chemotherapy regimens. Objective: Our objective was to develop a predictive model of the life expectancy of GBM patients using data on tumor cells’ sensitivity to chemotherapy drugs, as well as the levels of blood cells and proteins forming the tumor microenvironment. Methods: The investigation included 31 GBM patients from the Almazov Medical Research Centre (Saint Petersburg, Russia). The cytotoxic effects of chemotherapy drugs on GBM cells were studied by an MTT test using a 50% inhibitory concentration (IC₅₀). We analyzed the data with life expectancy by a one-way ANOVA, principal component analysis (PCA), ROC, and Kaplan–Meier survival tests using GraphPad Prism and Statistica 10 software. Results: We determined in vitro the IC₅₀ of six chemotherapy drugs for GBM and 32 clinical and biochemical blood indicators for these patients. This model includes an assessment of only three parameters: IC₅₀ of tumor cells to carboplatin (CARB) higher than 4.115 μg/mL, as well as levels of band neutrophils (NEUT-B) below 2.5% and total protein (TP) above 64.5 g/L in the blood analysis, which allows predicting with 83.3% probability (sensitivity) the life expectancy of patients for 15 months or more. In opposite, a change in these parameters—CARB above 4115 μg/mL, NEUT-B below 2.5%, and TP above 64.5 g/L—predict with 83.3% probability (specificity) no survival rate of GBM patients for more than 15 months. The relative risk for CARB was 6.41 (95 CI: 4.37–8.47, p = 0.01); for NEUT-B, the RR was 0.40 (95 CI: 0.26–0.87, p = 0.09); and for TP, it was 2.88 (95 CI: 1.57–4.19, p = 0.09). Overall, the model predicted the risk of developing a positive event (an outcome with a life expectancy more than 10 months) eight times (95 CI 6.34–9.66, p < 0.01). Cross k-means validation on three clusters (n = 10) of the model showed that its average accuracy (sensitivity and specificity) for cluster 1 was 74.98%; for cluster 2, it was 66.7%; and for cluster 3, it was 60.0%. At the same time, the differences between clusters 1, 2, and 3 were not significant. The results of the Sobel test show that there are no interactions between the components of the model, and each component is an independent factor influencing the event (life expectancy, survival) of GBM patients. Conclusions: A simple predictive model for GBM patients’ life expectancy has been developed using statistical analysis methods.

Mercury poisoning has a cumulative effect. Mercury gradually accumulates in tissues and organs, which negatively affects the functions of all body systems, especially the brain. The aim of this study was to investigate the neuropeptides content in the blood serum of Wistar rats after subchronic low-dose mercury acetate poisoning. During the study, rats was intragastrically administered mercury acetate at a dose of 4 mg/kg for 30 days. On days 30 and 44, the blood serum of rats was tested for the levels of calcium-binding protein (S-100), glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), pigment epithelial-derived factor (PEDF), myelin basic protein (MBP). The concentration of S-100 protein in the blood serum of the experimental group of rats decreased by 43.9%, and the concentration of MBP increased by 172.6%. Fourteen days after the end of the toxicant administration, the concentration of protein S-100 in the blood serum of poisoned animals was significantly lower by 132.7% compared to the control group. The content of MBP increased by 59.4% and neuron-specific enolase increased by 44.6%, the concentration of neuropeptides PEDF and GFAP changed insignificantly. The results obtained demonstrate that even low concentrations of mercury acetate, entering the body for a long time, affect the concentration of neuropeptides in blood serum, which indicates negative changes in the central nervous system of rats.

Модифицированный эффект пептидных препаратов на спонтанную двигательную активность самцов крыс в условиях светового десинхроноза

BACKGROUND: Disruption of circadian rhythms can cause significant damage to sensory processing, learning, and memory. At the same time, the structure of the endogenous biological clock contributes to the adaptation of the organism to changes in the conditions for the existence of a biosystem in the external environment. The possibility of synchronization of the endogenous rhythms of the organism with disturbed light periodicity is an urgent problem of modern society, where different rhythms of labor, motor, cognitive activity are used. AIM: To study the effect of peptides from the pituitary gland of the Reindeer on the parameters of cognitive functions in rats with a long-term change in the light regime on models with altered cellular oscillation due to oxidative stress caused by poisoning of animals with sodium thiopental in a half-lethal dose. MATERIALS AND METHODS: The study was conducted on 56 white Wistar male rats after acute poisoning with sodium thiopental at a dose of 85 mg/kg under conditions of light desynchronosis. In the passive avoidance conditioned reflex test, the cognitive functions of animals were assessed after a two-week pharmacological correction with a cellular extract of the pituitary gland of the Reindeer at a dose of 100 mg/kg. RESULTS: The peptide extract of the pituitary gland of the Reindeer contributes to the change in the higher integrative functions of the central nervous system in case of disturbed periodicity of the light signal. The results obtained indicate the chronobiotic activity of the peptide extract of the pituitary gland of the Reindeer at a dose of 100 g/kg when administered intranasally. CONCLUSIONS: The light regime change for 1 month under conditions of altered cellular oscillation led to impaired of the higher integrative functions of the central nervous system in rats, which was accompanied by an increase in the rate of reflex extinction and a disturbance of the processes of memory consolidation; under conditions of constant light, these disorders are more pronounced. The result of the pharmacological correction of these changes with the reindeer pituitary peptide extract was an improvement in the processes of memory consolidation and information reproduction (an increase in the number of trained animals with a change in the light regime).