The Effect of Flux Dysconnectivity Functions on Concentration Gradients Changes in a Multicomponent Model of Convectional Reaction-Diffusion by the Example of a Neurovascular Unit

Nartsissov, Yaroslav R.

doi:10.4028/www.scientific.net/ddf.413.19

Cited by 8 publications

(5 citation statements)

References 37 publications

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“…Важнейшим открытием последних лет стало описание прямого действия глицина на дилатацию микрососудов артериол и капилляров, что является основным аспектом гемодинамического воздействия данной аминокислоты на состояние ЦНС [34,35]. Воздействуя на систему микроциркуляции, регулируя кровоток в артериолах и капиллярах, прием глицина приводит к экспериментально подтвержденному увеличению содержания глюкозы в нейрональной ткани и улучшению ее функционирования [36][37][38][39]. Таким образом, в настоящем исследовании у пациентов с основными проявлениями постковидного 2023;17 (10):168-176 Практика синдрома, получавших эффективную дозу глицина в составе биологически активной добавки к пище Метабовит ® Здоровый сон, были получены положительные эффекты в отношении как когнитивного спектра жалоб, так и эмоциональных нарушений.…”

Section: Discussionunclassified

Experience of effective correction of the main manifestations of postcovid syndrome

Shishkova,

Shishkov,

Ustarbekova

et al. 2023

Medicinskij sovet

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Introduction. Postcovid syndrome is an urgent problem, due to its high frequency regardless of the severity of the infection and the age of the patient.Aim. To evaluate the efficacy and safety of the use of a dietary supplement Metabovit® Healthy Sleep with Glycine and Zinc in patients with postcovid syndrome.Materials and methods. 50 patients with postcovid syndrome were included in the study, after randomization, Metabovit® Healthy Sleep was added to therapy in group 1 (2 tablets 3 times a day), in group 2 patients received basic therapy for chronic diseases. The duration of observation was 21 days. Before and after the end of the study all patients underwent clinical and neuropsychological examination, which included: complaint analysis, the “Schulte tables” test, a verbal association test, a Trail Making Test, an MFI-20 self-questionnaire, a Reader test, a questionnaire on the level of life exhaustion, a hospital scale of anxiety and depression (HADS).Results. In the group of patients receiving Metabovit® Healthy Sleep 2 tablets 3 times a day, in comparison with the control group, the overall MFI-20 self-questionnaire score sugnificantly (p < 0.001) decreased by 16 [-19, -8] to 59 [52; 63] points performance time of "Schulte tables" test decreased by more than 13 seconds; performance time of the Trail Making Test was 26 seconds faster in part A and 40 seconds faster in part B, in the verbal association test, the results reached normative values for most participants; stress levels decreased by almost 25% in men and 11% in women; the indicator of life exhaustion decreased by 22%; the level of anxiety (HADS score) decreased by 5 [-7; -3] points which led to the normalization of this indicator in almost all participants of the group. By the end of the study, no significant changes in the studied parameters were detected in patients of the control group.Conclusion. In the group of patients who received the Metabovit® Healthy Sleep dietary supplement, there was a significant positive dynamics and regression of most of the symptoms of postcovid syndrome, in comparison with the control group.

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Section: Discussionunclassified

Experience of effective correction of the main manifestations of postcovid syndrome

Shishkova,

Shishkov,

Ustarbekova

et al. 2023

Medicinskij sovet

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“…A physical background of this phenomenon has previously been explained (Nartsissov, 2021a). The increased CBF always causes an enhanced amplitude of the glucose gradient in Ω II because the level of this metabolite will continuously raise up with an incoming flow according to Eq.…”

Section: Figurementioning

confidence: 93%

Application of a multicomponent model of convectional reaction-diffusion to description of glucose gradients in a neurovascular unit

Nartsissov

2022

Front. Physiol.

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A supply of glucose to a nervous tissue is fulfilled by a cerebrovascular network, and further diffusion is known to occur at both an arteriolar and a microvascular level. Despite a direct relation, a blood flow dynamic and reaction-diffusion of metabolites are usually considered separately in the mathematical models. In the present study they are coupled in a multiphysical approach which allows to evaluate the effects of capillary blood flow changes on near-vessels nutrient concentration gradients evidently. Cerebral blood flow (CBF) was described by the non-steady-state Navier-Stokes equations for a non-Newtonian fluid whose constitutive law is given by the Carreau model. A three-level organization of blood–brain barrier (BBB) is modelled by the flux dysconnectivity functions including densities and kinetic properties of glucose transporters. The velocity of a fluid flow in brain extracellular space (ECS) was estimated using Darcy’s law. The equations of reaction-diffusion with convection based on a generated flow field for continues and porous media were used to describe spatial-time gradients of glucose in the capillary lumen and brain parenchyma of a neurovascular unit (NVU), respectively. Changes in CBF were directly simulated using smoothing step-like functions altering the difference of intracapillary pressure in time. The changes of CBF cover both the decrease (on 70%) and the increase (on 50%) in a capillary flow velocity. Analyzing the dynamics of glucose gradients, it was shown that a rapid decrease of a capillary blood flow yields an enhanced level of glucose in a near-capillary nervous tissue if the contacts between astrocytes end-feet are not tight. Under the increased CBF velocities the amplitude of glucose concentration gradients is always enhanced. The introduced approach can be used for estimation of blood flow changes influence not only on glucose but also on other nutrients concentration gradients and for the modelling of distributions of their concentrations near blood vessels in other tissues as well.

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“…Примечательно, что глицин оказывает прямое действие на дилатацию артериол Том 10, Выпуск 5, 2022 [50,51], что является важнейшим аспектом общего воздействия данной аминокислоты на состояние ЦНС [52]. Воздействие на систему кровотока в микрососудах и капиллярах приводит к теоретически обоснованному [53][54][55] и экспериментально подтвержденному увеличению содержания глюкозы в тканях [56].…”

Section: иные сопутствующие и метаболические эффекты глицинаunclassified

Molecular Mechanisms Defining Application of Glycine and Zinc Combinationin Correction of Stress and Anxiety Main Manifestations

Shishkova

Nartsissov

Titova

et al. 2022

Farm. farmakol. (Pâtigorsk)

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The aim of the work was to carry out a systematic analysis of the molecular mechanisms that determine the possibility of a combined use of amino acid glycine and zinc compounds for the treatment of patients with manifestations of stress and anxiety.Materials and methods. Information retrieval (Scopus, PubMed) and library (eLibrary) databases were used as research tools. In some cases, the ResearchGate application was applied for a semantic search. The analysis and generalization of references was carried out on the research topic, covering the period from 2000 to the present time.Results. It has been shown that amino acid glycine, along with gamma-aminobutyric acid (GABA), is a key neurotransmitter that regulates physiological inhibition processes in the central nervous system (CNS) by increasing transmembrane conductance in specific pentameric ligand-gated ion channels. The introduction of zinc ions can potentiate the opening of these receptors by increasing their affinity for glycine, resulting in an inhibitory processes increase in CNS neurons. The replenishment of the glycine and zinc combined deficiency is an important element in the correction of a post-stress dysfunction of the central nervous system. A balanced intake of zinc and glycine is essential for most people who experience daily effects of multiple stresses and anxiety. This combination is especially useful for the people experiencing a state of chronic psycho-emotional stress and maladaptation, including those who have a difficulty in falling asleep.Conclusion. A balanced maintenance of the zinc and glycine concentration in the body of a healthy person leads to the development of a stable anti-anxiety effect, which is accompanied by the normalization of the sleep-wake rhythm, which makes it possible to have a good rest without any loss of working efficiency after waking up.

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The Effect of Flux Dysconnectivity Functions on Concentration Gradients Changes in a Multicomponent Model of Convectional Reaction-Diffusion by the Example of a Neurovascular Unit

Cited by 8 publications

References 37 publications

Experience of effective correction of the main manifestations of postcovid syndrome

Experience of effective correction of the main manifestations of postcovid syndrome

Application of a multicomponent model of convectional reaction-diffusion to description of glucose gradients in a neurovascular unit

Molecular Mechanisms Defining Application of Glycine and Zinc Combinationin Correction of Stress and Anxiety Main Manifestations

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