Animal models mimicking human transient ischemic attack (TIA) and cerebral microinfarcts are essential tools for studying their pathogenetic mechanisms and finding methods of their treatment. Despite its advantages, the model of single arteriole photothrombosis requires complex experimental equipment and highly invasive surgery, which may affect the results of further studies. Hence, to achieve high translational potential, we focused on developing a TIA model based on photothrombosis of arterioles to combine good reproducibility and low invasiveness. For the first time, noninvasive laser speckle contrast imaging (LSCI) was used to monitor blood flow in cerebral arterioles and reperfusion was achieved. We demonstrate that irradiation of mouse cerebral cortical arterioles using a 532-nm laser with a 1-mm-wide beam at 2.4 or 3.7 mW for 55 or 40 s, respectively, after 15 mg/kg intravenous Rose Bengal administration, induces similar ischemia-reperfusion lesions resulting in microinfarct formation. The model can be used to study the pathogenesis of spontaneously developing cerebral microinfarcts in neurodegeneration. Reducing the exposure times by 10 s while maintaining the same other parameters caused photothrombosis of the arteriole with reperfusion in less than 1 h. This mode of photodynamic exposure caused cellular and subcellular level ischemic changes in neurons and promoted the activation of astrocytes and microglia in the first day after irradiation, but not later, without the formation of microinfarcts. This mode of photodynamic exposure most accurately reproduced human TIA, characterized by the absence of microinfarcts.

The article presents the results of structural and functional transformations in cerebellum, trigeminal nuclei, and hippocampus of male Wistar rats against the background of injection of mesenchymal stem cells (MSCs) into Meckel’s space in the temporomandibular joint (TMJ) inflammation model. The aim of the study was to clarify the effect of MSCs injections into Meckel’s space on the morphostructural features of cerebellum, trigeminal nuclei, and hippocampus in the TMJ inflammation model. Injecting the mesenchymal stem cells into Meckel’s space in an inflammatory model of the right lower temporomandibular joint promotes the structure restoration of the ganglionic layer of the cerebellum, the spinal nuclei of the trigeminal nerve, and the hippocampus of rats by the 28th day. This is manifested in increasing the neuronal density, decreasing the neurodegeneration index, and in activating glia elements.

Введение. Разработка новых подходов к лечению онкологических заболеваний с использованием мышей – опухоленосителей аденокарциномы Эрлиха актуальна, поскольку данный аспект исследования позволяет получить адекватные, воспроизводимые результаты, имеющие перспективы применения в клинической практике. Однако анализ сведений из источников доступной научной литературы показал недостаточную изученность изменения гематологических показателей крови у лабораторных мышей-опухоленосителей. Цель. Оценка особенностей изменения морфологической картины крови мышей – опухоленосителей карциномы Эрлиха при разных, удовлетворяющих требованиям проведения эксперимента, ее биологических моделях. Материалы и методы. Исследование осуществлено на самках аутбредных мышей ICR и самцах инбредных мышей линии Af 2–3-месячного возраста, массой 20,0±2,0 г. Экспериментальные группы были сформированы следующим образом: группа 1 – моделирование АКЭ проводили внутрибрюшинным введением клеток аденокарциномы Эрлиха (в/б) самкам аутбредных мышей ICR (n=20); группа 2 – моделирование СКЭ проводили подкожным введением клеток аденокарциномы Эрлиха (п/к) самкам аутбредных мышей ICR (n=20); группа 3 – моделирование СКЭ проводилось подкожным введением клеток аденокарциномы Эрлиха (п/к) самцам инбредных мышей Af (n=20). Для перевивки опухоли был использован гипердиплоидный штамм аденокарциномы Эрлиха. Кровь забирали из лицевой вены мышей. Гематологические показатели определяли на автоматическом анализаторе URIT VET3000 Plus. Для подсчета лейкоцитарной формулы окрашенные по Романовскому – Гимзе мазки крови просматривали на световом микроскопе LEICA DM2500. Статистическую обработку данных проводили с использованием t-критерия Вилкоксона для зависимых выборок. Результаты между независимыми выборками анализировали с помощью критерия Манна – Уитни. Различия считали достоверными при р<0,05. Результаты. В исследовании установлены гематологические критерии развития опухолевого процесса в период 14 суток после ксенотрансплантации клеток аденокарциномы Эрлиха в объеме 0,2 мл в количестве 2×106 морфологических единиц. В эксперименте на животных созданы модели асцитной карциномы Эрлиха (АКЭ) и ее солидной формы (СКЭ) у самок мышей линии ICR и самцов мышей линии Af. Кровь забирали из лицевой вены мышей два раза: первый раз до прививки опухоли и второй раз на 14-е сутки развития опухолевого процесса. Выделены зависимые и независимые ни от вида, ни от пола, ни от способа инокуляции клеток аденокарциномы Эрлиха изменения параметров морфологической картины крови экспериментальных животных. Заключение. Ксенотрансплантация аденокарциномы Эрлиха мышам к 14-м суткам сопровождается следующими изменениями: в распределении эритроцитов по объему; среднем объеме тромбоцитов, распределении тромбоцитов по объему, количестве лимфоцитов, нейтрофилов, эозинофилов и не оказывает влияния на уровень базофилов крови. Количественные показатели крови мышей-опухоленосителей перспективны для обоснования выбора тест-систем и сопоставления эффективности потенциальных противоопухолевых субстанций, способных повлиять на систему крови. Introduction. The study of new approaches in the treatment of oncological diseases using Ehrlich adenocarcinoma mice is relevant and allows obtaining adequate, reproducible results that have prospects for application in clinical practice. However, the analysis of the sources of scientific literature showed a poor study of hematological blood parameters in laboratory mice-tumor carriers. Purpose. Evaluation of the peculiarities of changes in the morphological picture of blood of Ehrlich carcinoma tumor-bearing mice under different, satisfying the requirements of the experiment, its biological models. Materials and methods. The work was performed on female outbred ICR mice and male inbred Af mice aged 2–3 months, weighing 20.0±2.0 g. The experimental groups were formed as follows: group 1 – EAC modeling was performed by intraperitoneal injection of Ehrlich adenocarcinoma cells to female outbred ICR mice (n=20); group 2 – ESC modeling was performed by subcutaneous injection of Ehrlich adenocarcinoma cells to female outbred ICR mice (n=20); group 3 – ESC modeling was performed by subcutaneous injection of Ehrlich adenocarcinoma cells to male inbred Af mice (n=20). A hyperdiploid strain of Ehrlich’s adenocarcinoma was used for tumor transplantation. Blood was taken from the facial vein of mice. Hematological parameters were determined on an automatic analyzer URIT VET3000 Plus. To calculate the leukocyte count, Romanovsky – Giemsa- stained blood smears were examined using a LEICA DM2500 light microscope. Statistical processing was performed using the Wilcoxon t-test for dependent samples. The results between independent samples were analyzed using the Mann – Whitney test. Differences were considered significant at p<0.05. Results. Hematological criteria of the tumor process development in the period of 14 days after xenotransplantation of 0,2 ml Erlich adenocarcinoma cells in the amount of 2×106 morphological units were established in the research. We modeled Ehrlich ascites carcinoma (EAC) and its solid form (ESC) in female ICR mice and male ICR mice. Blood was collected from the facial vein of mice twice: the first time before tumor inoculation and the second time on the 14th day of tumor development. We distinguished the changes of the internal environment parameters which were dependent on neither species, nor sex, nor the way of Ehrlich adenocarcinoma cell inoculation. Conclusion. Xenotransplantation of adenocarcinoma of Ehrlich into mice by 14 days is accompanied by the following changes in: red blood cell volume distribution; average volume of platelets, distribution of platelets by volume, the number of lymphocytes, neutrophils, eosinophils, and has no effect on the level of blood basophils. Quantitative blood indicators of tumor-bearing mice are promising for justifying the choice of test system and the effectiveness of the strategy for the effectiveness of antitumor substances capable of indicators in the blood system.

Electron paramagnetic resonance (EPR) spectroscopy was used to record the content of nitric oxide (NO) and copper in brain tissues (frontal lobes and hippocampus) and liver of healthy rats and rats after ischemia modeling. Ischemia was simulated by ligation of the carotid arteries, followed by taking 3 ml of blood from the common carotid artery. Signals from triple complexes (DETC) were recorded by EPR spectroscopy of complexes (DETC)2-Fe2+-NO and Cu(DETC)2. Based on direct measurements by EPR spectroscopy, it was shown that a day after the modeling of ischemia, NO production in the hippocampus decreases by an average of 30% and there is a tendency to decrease NO in the frontal lobes and liver. The copper content decreased by an average of 3 times in the frontal lobes and the hippocampus by an average of 20% a day after ischemia modeling, and a tendency to decrease was noted in the liver. Thus, brain hypoxia is accompanied not only by a decrease in NO production, but also by signs of weakening of the antioxidant system in the hippocampus and frontal lobes, which further worsens the functional state of the homeostasis system.

Electron paramagnetic resonance (EPR) spectroscopy was used to record the content of nitric oxide (NO) and copper in brain tissues (frontal lobes and hippocampus) and liver of healthy rats and rats after ischemia modeling. Ischemia was simulated by ligation of the carotid arteries, followed by taking 3 ml of blood from the common carotid artery. Signals from triple complexes (DETC) were recorded by EPR spectroscopy of complexes (DETC) 2 -Fe 2+ -(NO) and Cu(DETC) 2 . Based on direct measurements by EPR spectroscopy, it was shown that a day after the modeling of ischemia, NO production in the hippocampus decreases by an average of 30% and there is a tendency to decrease NO in the frontal lobes and liver. The copper content decreased by an average of 3 times in the frontal lobes and the hippocampus by an average of 20% a day after ischemia modeling, and a tendency to decrease was noted in the liver. Thus, brain hypoxia is accompanied not only by a decrease in NO production, but also by signs of weakening of the antioxidant system in the hippocampus and frontal lobes, which further worsens the functional state of the homeostasis system. Keywords: electron paramagnetic resonance, spin trap, nitric oxide, cerebral ischemia, frontal lobes, hippocampus.

A comparative experimental analysis of intensity of nitric oxide (NO) production and the copper content in the tissues of hippocampus of male Wistar rats after modeling of hemorrhagic stroke and brain injury was conducted using EPR spectroscopy. Modeling of hemorrhagic stroke was carried out by microinjection of 500 nl of autologous blood into the brain to a depth of 5.0 mm (hippocampus) on the left side. Brain injury was performed by removing a piece of nerve tissue from 5.0 mm depth on the left side of hippocampus. It was registered a significant decrease in the NO content in hippocampus by 36 ± 17% on the 3rd day after modeling of hemorrhagic stroke together with decrease by an average of 24 ± 14% of the copper content. There were no significant changes in the NO level in hippocampus found neither on the 3rd day nor on the 7th day after brain injury modeling. There was also no change in copper content. Thus, it was experimentally demonstrated that modeling of brain injury, in contrast to hypoxia induced by hemorrhagic stroke, was not accompanied with significant changes in NO production in hippocampus of rat.

In the development of neurotechnologies, the search for applications for invasive neuroelectronic devices is relevant. One of the promising areas can be the development of ways of influencing intercellular communication, that is, not by acting on pre-, post- and extrasynaptic receptors, but on the extracellular matrix surrounding neurons and glia. For the development of bioelectronic pharmaceuticals, it is important to search for stimulation parameters at which a controlled change in the structural and functional parameters of the nervous tissue is possible. We considered one of the actual mechanisms of the molecular pathogenesis of SARS-CoV-2 infection - the induction of glycosaminoglycan metabolism. It is assumed that, getting into the olfactory epithelium and the olfactory bulbs of the brain, the virus is able to reach the structures of the central nervous system. When modeling changes in the enzymatic activity of hyaluronidase (0.1; 1.0; 10.0 U/ml) for 5 minutes in one of the key structures of the limbic system - the hippocampus (3-4-week-old ratpups, n = 64), the conditions for the transformation of intercellular contacts were revealed and evoked electrical activity of populations of CA1 region. The recorded development of synaptic plasticity processes has an adaptive potential at hyaluronidase concentrations not exceeding 1.0 U/ml. The in vitro method proposed in this work and a reasonable target for exposure - elements of the extracellular matrix, make it possible to simulate one of the mechanisms of the development of viral infection, optimize the process of preliminary screening of new medicinal substances that can minimize the risk of developing neuroinflammatory processes, and also substantiate the conditions for safe and/or therapeutic effects and electrical impulses on the elements of the nervous tissue.

Background: Frustrating statistics of therapy of patients with cerebral infarctions is well known.Longstanding deficiency of somatic and visceral functions is one of the negative consequences of existing therapy.Such state is developed due to persistent structural and functional lack of central control of various body activities by brain neural networks.Finally, most of the patients have severe invalidities even in distant period after performed treatment.Therefore, development and implementation of technologies that will allow activating reparative processes in brain after cerebral infarction is one of prospective tasks. Aims: development and implementation of new technique of cerebral infarctions treatment using autologous mesenchymal stem cells (MSC) of adipose tissue.Methods: Authors developed unique technique aimed at formation of conditions for natural migration of stem cells (SC) to the area of cerebral infarction after their endoscopic administration into nasal submucosa.Results: Autologous mesenchymal stem cells (MSC) of 25 patients naturally migrated to the area of cerebral infarction after their administration into nasal submucosa.The process of MSC differentiation into neuron-like elements after penetration to cranial cavity was previously shown in experiments.Patients with primary cerebral infarctions (n=12) and secondary ones (n=8) showed statistically significant improvement of physiological functions control in 6 months after course therapy with SC assessed by National Institutes of Health Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS), respectively.Administration of allogeneic SC to patients with cerebral infarctions (n=5) was ineffective. Discussion and Conclusion:Combination of standard therapy of cerebral infarctions with endoscopic perineural implantation of autologous MSC of adipose tissue is accompanied with activation of reparative processes leading to recovery of neurologic functions.

Results of analysis of nitric oxide and copper content in rat liver and hippocampus after brain ischemia modeling are provided. The studies are carried out using the electron paramagnetic resonance spectroscopy method with spin traps. It was shown that, the day after brain ischemia modeling, nitric oxide content in hippocampus decreases on average by 50% and a tendency toward its decrease was observed in liver tissues. Two days after brain ischemia modeling, nitric oxide content in the brain recovered and a significant increase by 46% against control indices was observed in the liver. On the second day of the postischemic period, the copper content, which is associated with superoxide dismutase content, increased on average by 2.5-fold in the liver. No significant changes in copper content was found in the hippocampus.

Introduction. With a decrease in the oxygen content in the inhaled air, violations of the cerebral blood flow, brain ischemia occurs, which can end in an ischemic stroke. Aim. Comparative analysis of the intensity of nitric oxide (NO) production and the copper content in the olfactory bulb tissues of the brain of male Wistar rats after modeling an ischemic stroke. Materials and methods. Modeling of ischemic stroke by ligation at the bifurcation level of both common carotid arteries and measuring the content of NO and copper by EPR spectroscopy. Results. The relative changes in the number of NO-containing complexes and the copper content were estimated from the integrated signal intensity of the complexes (DETC)2-Fe2+-NO and (DETC)2- Cu. A significant decrease by 47 % after 1 and 57 % after 2 days, respectively, in the NO content in the olfactory bulb of the rat brain was found after the ischemia modeling. The level of NO production in rats that underwent ischemia simulation with simultaneous intranasal administration of mesenchymal stem cells (MSCs) was also reduced by 51 % after 1 and 70 % after 2 days, respectively, after ischemia modeling. There was no significant difference in the NO content in the rats after ischemia modeling with simultaneous intranasal administration of MSCs compared to the ischemic rats. The copper content, which corresponds to the level of superoxide dismutase 1 and 3, in the rat’s olfactory bulb tended to increase after ischemia modeling and it persisted for two days of observation (an increase of 50 % in both cases). Intranasal administration of MSCs was accompanied by a significant increase in the Cu content (by 89 %) 1 day after the ischemia modeling, and 2 days later – by a decrease in its content by 36 % (compared to the control). In the control animals that were not subjected to surgical operations, no changes in the content of NO or copper were observed. Conclusion. The experiments showed a 2-fold decrease in the NO content in the olfactory bulb of the rat brain 1 and 2 days after the ischemia modeling, and demonstrated that the intranasal administration of MSCs did not affect the intensity of NO production on the 1st and 2nd days after the brain ischemia modeling, but was accompanied by an increase in the antioxidant protection of the nervous tissue one day after ischemia.

Direct measurements of the content of nitric oxide (NO) by the method of spectroscopy of electron paramagnetic resonance were performed. It was found that NO production in hippocampus tissues decreased to 46% after 5 h of ischemic stroke as compared to the control group and remained at the same level after 72 h. Following the hemorrhagic stroke, the level of NO production in the hippocampus decreased to 32% after 5 h of hemorrhagic stroke of the control level. After 72 hours of hemorrhagic stroke NO production was higher than after 5 h and amounted to 48% of the level of intact animals.

Electron paramagnetic resonance (EPR) was used as a method to record nitric oxide (NO) production in the tissues of the brain, heart and liver of healthy rats, and rats after modeling of ischemic stroke. Direct measurement of the dynamics of NO production by EPR spectroscopy in our experiments showed that after the emergence of signs of ischemic stroke, 5 h after the start of ischemia, the content of NO in the hippocampus decreased two- to threefold and this decrease was maintained at 24 and 72 h. Deserving special attention is the data demonstrating that there is a greater decrease of NO production in the tissues of the heart and liver than in the brain. Consequently, the change in intensity of NO production in the modeling of ischemic events in the brain has a systemic, not a local character.