Inhibition of Neuronal Necroptosis Mediated by RIPK1 Provides Neuroprotective Effects on Hypoxia and Ischemia In Vitro and In Vivo

Ischemic brain injury is a widespread pathological condition, the main components of which are a deficiency of oxygen and energy substrates. In recent years, a number of new forms of cell death, including necroptosis, have been described. In necroptosis, a cascade of interactions between the kinases RIPK1 and RIPK3 and the MLKL protein leads to the formation of a specialized death complex called the necrosome, which triggers MLKL-mediated destruction of the cell membrane and necroptotic cell death. Necroptosis probably plays an important role in the development of ischemia/reperfusion injury and can be considered as a potential target for finding methods to correct the disruption of neural networks in ischemic damage. In the present study, we demonstrated that blockade of RIPK1 kinase by Necrostatin-1 preserved the viability of cells in primary hippocampal cultures in an in vitro model of glucose deprivation. The effect of RIPK1 blockade on the bioelectrical and metabolic calcium activity of neuron-glial networks in vitro using calcium imaging and multi-electrode arrays was assessed for the first time. RIPK1 blockade was shown to partially preserve both calcium and bioelectric activity of neuron-glial networks under ischemic factors. However, it should be noted that RIPK1 blockade does not preserve the network parameters of the collective calcium dynamics of neuron-glial networks, despite the maintenance of network bioelectrical activity (the number of bursts and the number of spikes in the bursts). To confirm the data obtained in vitro, we studied the effect of RIPK1 blockade on the resistance of small laboratory animals to in vivo modeling of hypoxia and cerebral ischemia. The use of Necrostatin-1 increases the survival rate of C57BL mice in modeling both acute hypobaric hypoxia and ischemic brain damage.

Synthetic recovery of impulse propagation in myocardial infarction via silicon carbide semiconductive nanowires

Myocardial infarction causes 7.3 million deaths worldwide, mostly for fibrillation that electrically originates from the damaged areas of the left ventricle. Conventional cardiac bypass graft and percutaneous coronary interventions allow reperfusion of the downstream tissue but do not counteract the bioelectrical alteration originated from the infarct area. Genetic, cellular, and tissue engineering therapies are promising avenues but require days/months for permitting proper functional tissue regeneration. Here we engineered biocompatible silicon carbide semiconductive nanowires that synthetically couple, via membrane nanobridge formations, isolated beating cardiomyocytes over distance, restoring physiological cell-cell conductance, thereby permitting the synchronization of bioelectrical activity in otherwise uncoupled cells. Local in-situ multiple injections of nanowires in the left ventricular infarcted regions allow rapid reinstatement of impulse propagation across damaged areas and recover electrogram parameters and conduction velocity. Here we propose this nanomedical intervention as a strategy for reducing ventricular arrhythmia after acute myocardial infarction.

The Effects of Wearing a Medical Mask on the Masticatory and Neck Muscle Activity in Healthy Young Women

The objective of this study was to analyze the influence of wearing a medical mask on masticatory and neck muscle activity in healthy young women. We recruited 66 healthy women aged from 18 to 30 years (mean 23.6 ± 2.3 years). The temporalis anterior (TA), the superficial part of the masseter muscle (MM), the anterior bellies of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) potentials were recorded at rest and during functional activity using an eight-channel device for surface electromyography—BioEMG IIITM. There was a statistically significant decrease in mean TA activity during medical mask measurement compared to no mask examination at rest (2.16 µV vs. 2.58 µV; p = 0.05; ES = 0.2). Significant decreases in resting RMS values were also observed during the medical mask phase in comparison to no mask examination concerning the left MM (1.75 µV vs. 2.17 µV; p = 0.01; ES = 0.3), and mean bioelectrical activity of the MM (1.81 µV vs. 2.15 µV; p = 0.02; ES = 0.2). The differences between the two conditions did not reach the assumed significance level (p > 0.05) in terms of other indices. Wearing a medical mask has a small effect on decreasing the resting potentials of the temporalis anterior and masseter muscles without changing the parameters of activity and asymmetry within the stomatognathic system.

The Association between Symmetrical or Asymmetrical High-Arched Feet and Muscle Fatigue in Young Women

The foot arches are responsible for proper foot loading, optimal force distribution, and transmission throughout the soft tissues. Since the foot arch is an elastic structure, able to adapt to forces transmitted by the foot, it was reported that low arch is related to excessive foot pronation, while high arched foot is more rigid and inflexible. Therefore, it is also probable, that foot arch alterations may change the force transmission via myofascial chains. The objective of this study was to evaluate the effect of symmetrical and asymmetrical excessive feet arching on muscle fatigue in the distal body parts such as the lower limbs, trunk, and head. Seventy-seven women (25.15 ± 5.97 years old, 62 ± 10 kg, 167 ± 4 cm) were assigned to three groups according to the foot arch index (Group 1—both feet with normal arch, Group 2—one foot with normal arch and the other high-arched, Group 3—both feet with high-arch). The bioelectrical activity of the right and left hamstrings muscles, erector spine, masseter, and temporalis muscle was recorded by sEMG during the isometric contraction lasting for 60 s. The stable intensity of the muscle isometric contraction was kept for all the time during the measurement. Mean frequency difference (%), slope (Hz), and intercept (Hz) values were calculated for muscle fatigue evaluation. No differences were observed in fatigue variables for all evaluated muscles between the right and left side in women with symmetrical foot arches, but in the group with asymmetric foot arches, the higher muscle fatigue on the normal-arched side compared to the high-arched side was noted. Significantly greater values of the semitendinosus—semimembranosus muscle frequency difference was observed on the normal-arched side compared to the high-arched side (p = 0.04; ES = 0.52; −29.5 ± 9.1% vs. −24.9 ± 8.4%). In the group with asymmetric foot arches, a significantly higher value of lumbar erector spinae muscle frequency slope (p = 0.01; ES = 1.32; −0.20 ± 0.04 Hz vs. −0.14 ± 0.05 Hz) and frequency difference (p = 0.04; ES = 0.92; −7.8 ± 3.1% vs. −4.8 ± 3.4%) were observed on the high-arched foot side compared to the side with normal foot arching. The thoracic erector spine muscle frequency slope was significantly larger in women with asymmetrical arches than in those with both feet high-arched (right side: p = 0.01; ES = 1.25; −0.20 ± 0.08 Hz vs. −0.10 ± 0.08 Hz); (left side: p = 0.005; ES = 1,17; −0.19 ± 0.04 Hz vs. −0.13 ± 0.06 Hz) and compared to those with normal feet arches (right side: p = 0.02; ES = 0.58; −0.20 ± 0.08 Hz vs. −0.15 ± 0.09 Hz); (left side: p = 0.005; ES = 0.87; −0.19 ± 0.04 Hz vs. −0.14 ± 0.07 Hz). In the group with asymmetric foot arches, the frequency difference was significantly higher compared to those with both feet high-arched (right side: p = 0.01; ES = 0.87; −15.4 ± 6.8% vs. 10.4 ± 4.3%); (left side: p = 0.01; ES = 0.96; 16.1 ± 6.5% vs. 11.1 ± 3.4%). In the group with asymmetric foot arches, a significantly higher value of the masseter muscle frequency difference was observed on the high-arched side compared to the normal-arched side (p = 0.01; ES = 0.95; 6.91 ± 4.1% vs. 3.62 ± 2.8%). A little increase in the longitudinal arch of the foot, even though such is often not considered as pathological, may cause visible changes in muscle function, demonstrated as elevated signs of muscles fatigue. This study suggests that the consequences of foot high-arching may be present in distal body parts. Any alterations of the foot arch should be considered as a potential foot defect, and due to preventing muscle overloading, some corrective exercises or/and corrective insoles for shoes should be used. It can potentially reduce both foot overload and distant structures overload, which may diminish musculoskeletal system pain and dysfunctions.

RATIO OF TOTAL SLOW AND SUPER SLOW CEREBRAL BIOELECTRICAL ACTIVITY IN CHILDREN WITH HYPOXIA

The aim of the study is to identify changes in the total slow and super slow bioelectric activity of the cerebral hemispheres in 8–11-year-old children under reduced oxygen partial pressure in the inhaled air and in norm. Materials and Methods. The authors examined 82 8–11-year-old children. EEG registration was carried out on a complex Russian device "Telepat-103" with computer processing of the results. Slow potentials were recorded using a special computer complex for studying constant potential level (CPL) and cerebral energy consumption "Neuroenergon". Hypoxia was created by a special medical device "Hypoxicator" (Trade Medical). The choice of the oxygen content in the test hypoxic mixture (14 % O2) was based on the results of a three-stage hypoxic test carried out before the complex examination. Results. Hypoxia increases the index and amplitude of delta oscillations and decreases the number of alpha waves in 8–11-year-old children. The results obtained indicate that it is more important to provide the brain with a sufficient amount of oxygen corresponding to its needs than simply to increase the brain blood supply during hypoxia. The study also indicates the contribution of the body's sensitivity to hypoxic response. Under hypoxia, an increase in the constant potential level in the studied brain areas is observed in 8–11-year-old children. An increase in electrical activity during normobaric hypoxia is noted at low baseline values of constant potential level. An increase in the slow electrical brain activity occurs due to the change of brain energy supply according to the biochemical indicators of energy metabolism. Short-term hypoxia is accompanied by a simultaneous increase in slow-wave activity due to delta activity and CPL in 8–11-year-old children. Conclusion. Thus, we can say that a picture of functional brain activity with simultaneous inhibitory phenomena in the cortex is formed. It may reflect the development of a special state of the central nervous system. Key words: constant potential level, electroencephalography, hypoxia, adaptation to hypoxia. Цель работы – выявление изменений суммарной медленной и сверхмедленной биоэлектрической активности полушарий головного мозга у детей в возрасте от 8 до 11 лет в условиях нормального и сниженного парциального давления кислорода во вдыхаемом воздухе. Материалы и методы. Обследовано 82 ребенка 8–11-летнего возраста. Регистрация ЭЭГ осуществлялась на комплексной отечественной установке «Телепат-103» с компьютерной обработкой результатов. Медленные потенциалы фиксировались с помощью специального компьютерного комплекса для исследования уровня постоянных потенциалов (УПП) и энергозатрат головного мозга «Нейроэнергон». Гипоксические условия создавались аппаратом «Гипоксикатор» фирмы Trade Medical. Выбор содержания кислорода в тестирующей гипоксической смеси (14 % О2) основывался на результатах проведенного до комплексного обследования трехступенчатого гипоксического теста. Результаты. У детей от 8 до 11 лет действие гипоксии на головной мозг приводит к возрастанию индекса и амплитуды дельта-колебаний и убыванию числа альфа-волн. Полученные результаты говорят о том, что большое значение имеет не столько усиление кровоснабжения головного мозга при гипоксии, сколько обеспечение мозга достаточным, соответствующим его потребностям, количеством кислорода, а также о роли чувствительности организма к гипоксии. При воздействии гипоксии у детей этого возраста наблюдается возрастание уровня постоянных потенциалов в исследуемых областях головного мозга. При низких фоновых значениях уровня постоянных потенциалов отмечается возрастание электрической активности при нормобарической гипоксии. Возрастание медленной электрической активности головного мозга происходит из-за того, что изменяется энергообеспечение головного мозга по биохимическим показателям энергетического обмена. Действие кратковременной гипоксии сопровождается одновременным возрастанием медленноволновой активности за счет дельта-активности и УПП у детей от 8 до 11 лет. Выводы. Таким образом, можно говорить о том, что формируется своеобразная картина функциональной активности с одновременными тормозными явлениями в коре, что может являться отражением развития особого состояния центральной нервной системы. Ключевые слова: уровень постоянных потенциалов, электроэнцефалография, гипоксия, адаптация к гипоксии.

Rules for a routine electroencephalogram recording

Electroencephalography (EEG) is the primary method for functional assessment of the brain bioelectrical activity. It is the most effective for epilepsy diagnosing, and also used for localization of the epileptogenic zone in presurgical evaluation for pharmaco-resistant epilepsy and in critical care medicine. In practice, the most common type is a 'routine' EEG, the informative value of which depends largely on the accuracy of its performance. The paper briefly outlines the rules for performing a routine EEG and lists the most common mistakes that can affect its interpretation.

SOME ASPECTS OF ACUTE CEREBROVASCULAR PATHOLOGY IN POSTPARTUM WOMEN

В данной статье, представлены результаты обследования 17 женщин, перенесших острое нарушение мозгового кровообращения в послеродовом периоде, с 2017 по 2021 годы, в возрасте от 19 до 39 лет. Показано, что у женщин в послеродовом периоде, перенесших острое нарушение мозгового кровообращения, выявлено преобладание ишемического инсульта над геморрагическим, что составило 64,7% и 35,3% соответственно. Неврологические признаки церебрального инсульта в послеродовом периоде характеризуются двигательными, речевыми расстройствами, нарушением чувствительности, а также часто психоэмоциональными проявлениями. Генерализованные тонико-клонические приступы чаще наблюдались у пациенток с геморрагическим инсультом (33,3%), в сравнении с ишемическим инсультом (9,1%). У женщин в послеродовом периоде, перенесших острое нарушение мозгового кровообращения, наиболее значимыми факторами риска являются: наличие хронических заболеваний, в том числе отягощенный акушерско-гинекологический анамнез, прием пероральных контрацептивов, а также курение. Биоэлектрическая активность головного мозга характеризовалась выраженной дельта и тета активностью, эпилептиформными разрядами в виде острых волн, спайков и комплексов «пик-волна», с преобладанием у пациенток с геморрагическим инсультом. Более значительное повышение индекса когерентности в дельта и тета диапазонах у пациентов, перенесших геморрагический инсульт, может указывать на более грубые межполушарные нарушения, в сравнении с ишемическим инсультом. Отмечено повышение интегрального индекса диапазона медленно-волновой активности и преобладание процентного отношения спектральных мощностей медленных волн (дельта, тета) к быстрым волнам (альфа, бета), особенно выраженное у больных с геморрагическим инсультом (р < 0,05), в сравнении с ишемическим инсультом. Наиболее тяжелое течение послеродового периода наблюдалось у пациенток с геморрагическим инсультом, именно в этом случае было 2 летальных исхода. This article presents the results of a survey of 17 women with acute cerebrovascular accident in the postpartum period, from 2017 to 2021, aged 19 to 39 years. It is shown that the period in women in the postpartum period, who underwent acute cerebrovascular accident, revealed the prevalence of ischemic stroke over hemorrhagic, which amounted to 64,7% and 35,3%, respectively. Neurological signs of cerebral stroke in the postpartum period are characterized by movement, speech disorders, impaired sensitivity, and often psychoemotional manifestations. Generalized tonic-clonic seizures were more often observed in patients with hemorrhagic stroke (33,3%) in comparison with ischemic stroke (9,1%). In postpartum women who have suffered acute cerebrovascular accident, the most significant risk factors are: the presence of chronic diseases, including a burdened obstetric and gynecological history, taking oral contraceptives, as well as smoking. The bioelectrical activity of the brain was characterized by pronounced delta and theta activity, epileptiform discharges in the form of sharp waves, spikes and peak-wave complexes, with a predominance in patients with hemorrhagic stroke. A more significant increase in the coherence index in the delta and theta ranges in patients after hemorrhagic stroke may indicate more severe interhemispheric disorders in comparison with ischemic stroke. An increase in the integral index of the range of slow-wave activity and a predominance of the percentage of the spectral powers of slow waves (delta, theta) to fast waves (alpha, beta), especially pronounced in patients with hemorrhagic stroke (p <0,05), in comparison with ischemic stroke. The most severe postpartum period was observed in patients with hemorrhagic stroke, in this case there were 2 deaths.

CLINICAL AND ELECTROPHYSIOLOGICAL INDICATORS OF ACUTE AND EARLY RECOVERY PERIODS OF CEREBRAL STROKE

В остром и раннем восстановительном периодах церебрального инсульта взаимосвязь между биоэлектрической активностью головного мозга и клинической картиной заболевания представляют значительный научный и практический интерес. В данной статье, представлены результаты исследования клинико-неврологических и электроэнцефалографических показателей, в остром и раннем восстановительном периодах церебрального инсульта, 67 больных в возрасте от 43 до 78 лет. Показано, что у больных в остром и раннем восстановительном периодах церебрального инсульта на фоне двигательных и речевых расстройств, наблюдались легкие и умеренные когнитивные нарушения, а также тревожно-депрессивные проявления. Головная боль, соответствующая критериям головной боли напряжения отмечалась у 61,1% больных. Биоэлектрическая активность головного мозга характеризовалась выраженной дельта и тета активностью, а также единичными острыми волнами, спайками, преимущественно в пораженном полушарии головного мозга, межполушарной асимметрией, повышением мощности спектров в сторону преобладания медленных волн. Показатели индекса когерентности по всем отведениям были снижены, что свидетельствует о нарушении функциональных межполушарных взаимосвязей. Более значительное повышение индекса когерентности в дельта и тета диапазонах у пациентов, перенесших геморрагический инсульт, может указывать на более грубые межполушарные нарушения, в сравнении с ишемическим инсультом. In the acute and early recovery periods of cerebral stroke, the correlation between bioelectrical activity of the brain and the clinical picture of the disease is of considerable scientific and practical interest. This article presents the results of a study of clinical, neurological and electroencephalographic parameters, in the acute and early recovery periods of cerebral stroke, in 67 patients aged from 43 to 78. Mild and moderate cognitive impairment as well as anxiety and depressive manifestations were shown among patients in the acute and early recovery periods of cerebral stroke amid the motor and speech disorders. Headache meeting the criteria of tension headache was reported among 61,1% of patients. The bioelectrical activity of the brain was characterised by marked delta and theta activity as well as single sharp waves, commissures mainly in the affected cerebral hemisphere, interhemispheric asymmetry and by increase in the spectrum power towards the predominance of slow waves. The coherence index scores were decreased on all directions, indicating impaired functional interhemispheric connectivity. A greater increase in coherence index in the delta and theta bands among haemorrhagic stroke patients may indicate more severe interhemispheric disturbances compared to ischaemic stroke.

Assessment of the bioelectric activity of the masticatory muscles in orthopedic treatment with partial removable plate prostheses

Relevance. According to a number of authors, it is known that full adaptation to complete removable dentures occurs within 3 months [3–5, 9]. The main criterion for patients getting used to removable dentures is the synchronization of the work of the masticatory muscles and, as a consequence, the normalization of the chewing function.The aim of the study was to evaluate the bioelectrical activity of the masticatory muscles in patients using the CSPP.Materials and methods. In patients of the control (n = 23) and main (n = 63) groups, electromyographic examination was performed using the electroneuromyographic system "Synapsis" (Neurotechnology, Russia). Registration of the bioelectric activity of the chewing muscles was carried out directly on the day of applying the prostheses, after 1 and 3 months, respectively.Results and discussion. The electromyographic indices of the masticatory muscles in the patients of the control group decreased within one month after the treatment and amounted to 231 ± 18.2 μV for the right and 229 ± 16.1 μV for the left proper chewing muscles. The values were also reduced for the right and left temporal muscles – 228 ± 15.2 μV and 225 ± 24.1 μV (p < 0.05). It should be noted that the electromyographic parameters in patients of the main group were comparable to the lower limit of the norm and amounted to 269 ± 16.5 μV and 256 ± 20.4 μV, respectively, after one month of treatment.Conclusions. In the treatment of dysfunction of the temporomandibular joint with the use of thermoplastic prostheses, an increase in the biopotentials of the masticatory muscles is observed. In the orthopedic treatment of patients with terminal dentition defects using thermoplastic prostheses, the electromyographic parameters of the masticatory muscles are most close to normal after 3 months of using these prostheses.