Report of conference evaluation committee

A general classification is made of a number of approaches used for the prediction of turbulent shear flows. The sensitivity of these prediction methods to parameter values and initial data are discussed in terms of variable density, pressure fluctuation, gradient diffusion, low Reynolds number, and influence of geometry

Large-eddy simulation of hypersonic flows. Selective procedure to activate the sub-grid model wherever small scale turbulence is present

A new method for the localization of the regions where small scale turbulent fluctuations are present in hypersonic flows is applied to the large-eddy simulation (LES) of a compressible turbulent jet with an initial Mach number equal to 5. The localization method used is called selective LES and is based on the exploitation of a scalar probe function! which represents the magnitude of the stretching tilting term of the vorticity equation normalized with the enstrophy (Tordella et al., 2007) [3]. For a fully developed turbulent field of fluctuations, statistical analysis shows that the probability that f is larger than 2 is almost zero, and, for any given threshold, it is larger if the flow is under-resolved. By computing the spatial field off in each instantaneous realization of the simulation it is possible to locate the regions where the magnitude of the normalized vortical stretching tilting is anomalously high. The sub-grid model is then introduced into the governing equations in such regions only. The results of the selective LES simulation are compared with those of a standard LES, where the sub-grid terms are used in the whole domain, and with those of a standard Euler simulation with the same resolution. The comparison is carried out by assuming as reference field a higher resolution Euler simulation of the same jet. It is shown that the selective LES modifies the dynamic properties of the flow to a lesser extent with respect to the classical LES. In particular, the prediction of the enstrophy, mean velocity and density distributions and of the energy and density spectra are substantially improved

Traditional Japanese Herbal Medicine Yokukansan Targets Distinct but Overlapping Mechanisms in Aged Mice and in the 5xFAD Mouse Model of Alzheimer’s Disease

Yokukansan (YKS) is a traditional Japanese herbal medicine that has been used in humans for the treatment of several neurological conditions, such as age-related anxiety and behavioral and psychological symptoms (BPSD) related to multiple forms of dementia, including Alzheimer’s disease (AD). However, the cellular and molecular mechanisms targeted by YKS in the brain are not completely understood. Here, we compared the efficacy of YKS in ameliorating the age- and early-onset familial AD-related behavioral and cellular defects in two groups of animals: 18- to 22-month-old C57BL6/J wild-type mice and 6- to 9-month-old 5xFAD mice, as a transgenic mouse model of this form of AD. Animals were fed food pellets that contained YKS or vehicle. After 1–2 months of YKS treatment, we evaluated the cognitive improvements in both the aged and 5xFAD transgenic mice, and their brain tissues were further investigated to assess the molecular and cellular changes that occurred following YKS intake. Our results show that both the aged and 5xFAD mice exhibited impaired behavioral performance in novel object recognition and contextual fear conditioning (CFC) tasks, which was significantly improved by YKS. Further analyses of the brain tissue from these animals indicated that in aged mice, this improvement was associated with a reduction in astrogliosis, microglia activation and downregulation of the extracellular matrix (ECM), whereas in 5xFAD mice, none of these mechanisms were evident. These results show the differential action of YKS in healthy aged and 5xFAD mice. However, both aged and 5xFAD YKS-treated mice showed increased neuroprotective signaling through protein kinase B/Akt as the common mode of action. Our data suggest that YKS may impart its beneficial effects through Akt signaling in both 5xFAD mice and aged mice, with multiple additional mechanisms potentially contributing to its beneficial effects in aged animals

N-acetylcysteine relieves neurologic signs of acute ethanol hangover in rats

Orally administered NAC before acute ethanol intoxication led to a decrease in the severity of neurological deficiency in rats and reduced the amnesic effect of ethanol. This could be due to an improvement of ethanol metabolism and a decrease in the severity of disorders associated with oxidative stress and liver dysfunctio

Considerations for Permitted Daily Exposure Calculation for Contaminants in Medicinal Products Manufactured in Shared Facilities

The manufacture of different medicinal products in shared facilities creates a risk of cross-contamination. One of the approaches to select the limits for possible contaminants is based on calculating the permitted daily exposure (PDE), i.e. the dose of an active pharmaceutical ingredient or any other substance contaminating a medicinal product that will not be associated with any adverse events in a human in the case of lifetime exposure. The aim of this study was to provide practical guidance on selecting adjustment factors for calculating PDEs to establish limits for potential contaminants in multi-purpose pharmaceutical facilities. The authors analysed the regulatory requirements and literature needed to establish critical effects of contaminants, outlined possible assumptions in the use of quantitative indicators for measuring toxicity, and described the relationship between the PDE and other indicators of the safety of chemical compounds for human health. The article presents an example of PDE calculation for an investigational hypoglycemic medicinal product using a limited amount of open-source literature data. Thus, the article demonstrates the role of information on the primary pharmacodynamic effects of medicinal products in the assessment of their critical effects, which is necessary to implement the most conservative approaches to PDE calculation. The example of PDE calculation presented in the article may be used to assess cross-contamination risks associated with non-dedicated manufacturing facilities

ACTIVITY MODULATION OF VARIOUS NITRIC OXIDE SYNTASES AS AN APPROACH TO ENDOTHELIAL DYSFUNCTION THERAPY

Nitric oxide as a therapeutic approach to the treatment of cardiovascular diseases attracted the attention of researchers at the end of the 19th century. As a vasodilator, nitric oxide may be a unique therapeutic agent for the treatment of hypertension and, as a result, renal failure and left ventricular hypertrophy.The aim of the article is to analyze the literature data on possible ways of modulating the activity of various nitric oxide synthases as an approach to the treatment of endothelial dysfunction.Materials and methods. When searching for materials for writing a review article, such abstract databases as PubMed, Google Scholar, e-Library, etc., were used. The search was carried out on the publications for the period from 1990 to 2021. The following words and phrases were chosen as parameters for the literature selection: nitric oxide; NO synthase; endothelial dysfunction; NO synthase activator; NO synthase inhibitor.The following words and phrases were chosen as parameters for the literature selection:Results. The article presents the history of the nitric oxide discovery and its biological role, the process of its biosynthesis, as well as the isoforms of its synthesizing enzymes (NOS): neuronal – nNOS, endothelial – eNOS and inducible iNOS, and their role in normal and pathological physiology. The process of NOS uncoupling (its molecular mechanisms) has been considered as the basis of endothelial dysfunction.The examples of the pharmacological correction (BH4, arginase inhibitors, statins, resveratrol) are presented. In addition, NO synthase activators (calcium dobesilate, cavNOxin, and some NOS transcription activators), as well as non-selective (L-NMMA, 1-NNA, L-NAME, ADMA, 546C88, VAS203) and selective (L-NIO, 7-nitroindazole, aminoguanidine, L-NIL, GW273629, GW274150, cavtratin) inhibitors of nitric oxide synthasehave been described.Conclusion. Nitric oxide synthases continue to be promising targets for the development of agents that modulate their activity to correct various pathologies. As a therapeutic approach, modulation of the nitric oxide synthase activity can be implemented to treat endothelial dysfunction, which is the cause for complications of many diseases

HYPOGLYCEMIC EFFECT OF SITAGLIPTIN AND AMINOGUANIDINE COMBINATION IN EXPERIMENTAL DIABETES MELLITUS

The aim of the work was to determine the antidiabetic effect of a sitagliptin and aminoguanidine combination in rats with experimental diabetes mellitus.Materials and methods. The study was carried out on male Wistar rats and C57BL/KsJ-db/db mice. According to the models used, it was divided into 4 series, in which alloxan, steroid-induced (dexamethasone) and streptozotocin-nicotinamide-induced diabetes mellitus (DM) were formed, respectively, in rats, and in the 4 series, obese C57BL/KsJ-db/db mice were used. In the 1 and 2 series, the treatment was started prophylactically – 3 h after the alloxan administration and simultaneously with the dexamethasone administration, in the 3rd and 4th series, the treatment was carried out after the pathology had developed – 7 days after the streptozotocin with nicotinamide administration, and in the obese mice – immediately after their distribution according to the groups. The treatment was carried out with sitagliptin (10 mg/kg), aminoguanidine (25 mg/kg), or a combination thereof. The treatment was continued till the end of the experiment, which was completed with an oral glucose tolerance test (OGTT) after 4 h of fasting. The obtained data were subjected to statistical processing.Results. In the course of the experiments, it was found out that the prophylactic administration of a sitagliptin and aminoguanidine combination, unlike each of the components, prevented the development of alloxan DM. More effectively than the administration of sitagliptin alone, it reduced the severity of steroid-induced DM, which was expressed in a significantly lower level of fasting glycemia (after 4 h of fasting) and postprandial glycemia (during OGTT). Under the conditions of streptozotocin-nicotinamide-induced DM, the studied combination slowed down the progression of the pathology, and in the obese mice, the course therapeutic administration of sitagliptin and its combination reduced the severity of carbohydrate metabolism disorders (fasting glycemia) and increased the rate of glucose utilization.Conclusion. As an iNOS blocker, aminoguanidine enhances the antidiabetic effect of sitagliptin, preventing the development of alloxan diabetes and reducing the severity of steroid-induced DM when administered prophylactically. When administered therapeutically, it reduces the severity of streptozotocin-nicotinamide-induced DM in rats and type 2 DM in mice with a predisposition to obesity

Physiology, pharmacology and prospects for dipeptidilpeptidase-4 inhibitors use

Modern requirements for the treatment of type 2 diabetes mellitus (DM2) include not only achieving a glycemic control, but also reducing the risk of developing cardiovascular complications. Dipeptidyl peptidase 4 (DPP-4) inhibitors are inferior in the effectiveness to some other actively developing groups of hypoglycemic drugs (SGLT2 inhibitors and GLP-1 receptor agonists); however, they seem relevant at the present time.The aim of the study is to analyze the literature data on the therapeutic potential and results of the of DPP-4 inhibitors research.Materials and methods. When searching for the review article materials, the abstracting databases of PubMed, Google Scholar and e-Library were used. The search was carried out on the publications for the period from 2006 to 2022, using the following keywords: DPP-4 inhibitors; glucagonlike peptide-1 (GLP-1); glucose-dependent insulinotropic peptide (GIP); sitagliptin, and other drugs.Results. DPP-4 belongs to the serine proteases family and is involved in the degradation of various chemokines and peptide hormones, including incretins secreted by intestinal L- and K-cells – GLP-1 and GIP. They regulate a postprandial insulin secretion and a β-cell function, modulate a fasting and postprandial glucagon secretion, regulate the eating behavior and have many pleiotropic (immunomodulatory, anti-inflammatory, antifibrotic, etc.) effects. DPP-4 inhibitors reduce an enzyme activity by 70–90%, increasing plasma incretin levels by 2–4 times and have been used to treat DM2 since 2006. Now there are 13 DPP-4 inhibitors on the market in different countries, differing primarily in pharmacokinetic parameters. They are actively used in the combination therapy for type 2 diabetes, increasing the glycemic control effectiveness without increasing the risk of hypoglycemia. The evidence is emerging about the therapeutic potential of DPP-4 inhibitors in COVID-19.Conclusion. A peroral form, an ability to create effective combinations with other hypoglycemic drugs without increasing the risk of hypoglycemia, the pleiotropic effects of DPP-4 inhibitors, make this group relevant at the present time

Neuroprotective properties of GABA and its derivatives in diabetic encephalopathy in old animals

The aim of the work was to evaluate the GABA neuroprotective properties and its structural analogues in old animals after seven months of hyperglycemia.Materials and methods. Diabetes mellitus was modeled in white outbred male rats (12 months old) by the administration of a streptozotocin (65 mg/kg) and nicotinamide (230 mg/kg) combination. After 6 months, the animals with a postprandial glycemia level between 11 and 18 mmol/l were selected for the study. After the groups had been formed, the animals were administrated with GABA and GABAergic compounds (Compositions МРВАand PPC), respectively, for 1 month, the control group animals were administrated with saline. After the treatment, an oral glucose tolerance test and a set of behavioral tests aimed at studying sensory-motor (Open Field, Adhesion test, Rotarod) and cognitive functions (New Object Recognition and Morris Water Maze), as well as the functional state evaluation of the endothelium were performed. Further on, sampling of blood and brain tissues for a biochemical and enzyme immunoassay (the level of glucagon-like peptide-1 (GLP-1) and TNF-α in serum and the level of Klotho protein, BDNF, Nrf2, NF-κB and malondialdehyd (MDA) in brain homogenates), as well as a morphological analysis of changes in CA1 and CA3 neurons of the hippocampus and somatosensory cortex, was carried out.Results. GABA and compositions with its derivatives had a pronounced neuroprotective effect in old animals with prolonged hyperglycemia. The hypoglycemic effect of the studied compositions was accompanied by an increase in the production of GLP-1. In the animals with DM, after 6 weeks of the test substances administration, higher rates of sensory-motor and cognitive functions and a less structural damage to the sensory-motor cortex and the brain hippocampus were recorded. These effects may be due to higher levels of the Klotho proteins, Nrf2 and BDNF, as well as lower levels of NF-κB, which may underlie the suppression of the oxidative stress, the reduction of MDA and inflammation (TNF-α).Conclusion. After 6 weeks of the administration, GABA and its compositions in old animals (19 months old) significantly improved sensory-motor and cognitive functions, reduced negative structural changes in the hippocampus and somatosensory cerebral cortex

Особенности расчета допустимой ежедневной экспозиции контаминантов при производстве лекарственных препаратов на общих технологических линиях

The manufacture of different medicinal products in shared facilities creates a risk of cross-contamination. One of the approaches to select the limits for possible contaminants is based on calculating the permitted daily exposure (PDE), i.e. the dose of an active pharmaceutical ingredient or any other substance contaminating a medicinal product that will not be associated with any adverse events in a human in the case of lifetime exposure. The aim of this study was to provide practical guidance on selecting adjustment factors for calculating PDEs to establish limits for potential contaminants in multi-purpose pharmaceutical facilities. The authors analysed the regulatory requirements and literature needed to establish critical effects of contaminants, outlined possible assumptions in the use of quantitative indicators for measuring toxicity, and described the relationship between the PDE and other indicators of the safety of chemical compounds for human health. The article presents an example of PDE calculation for an investigational hypoglycemic medicinal product using a limited amount of open-source literature data. Thus, the article demonstrates the role of information on the primary pharmacodynamic effects of medicinal products in the assessment of their critical effects, which is necessary to implement the most conservative approaches to PDE calculation. The example of PDE calculation presented in the article may be used to assess cross-contamination risks associated with non-dedicated manufacturing facilities.Производство лекарственных препаратов на общих технологических линиях создает риск перекрестной контаминации. Одним из способов выбора пределов содержания возможных контаминантов является подход, основанный на расчете допустимой ежедневной экспозиции (permitted daily exposure, PDE) – дозы активной фармацевтической субстанции или другого контаминирующего вещества, потребление которой в течение всей жизни не будет ассоциировано у человека с нежелательными явлениями. Цель работы – представить методику определения коэффициентов для расчета значений PDE, используемых для установления пределов содержания потенциальных контаминантов на общих технологических линиях фармацевтических производств. Проанализированы требования нормативных документов и источники литературы, необходимые для оценки критически значимых эффектов контаминантов, приведены сведения о возможных допущениях при использовании токсикометрических показателей, описана взаимосвязь PDE с другими показателями, характеризующими безопасность химических соединений в отношении человеческого организма. Рассмотрен пример расчета PDE экспериментального лекарственного средства, обладающего гипогликемической активностью, на основании ограниченного объема данных, полученных из открытых источников. Продемонстрирована роль сведений о первичных фармакодинамических эффектах лекарственных средств в оценке их критических эффектов, необходимой для реализации наиболее консервативных подходов к расчету PDE. Предложенный в качестве примера порядок расчета значений PDE может быть использован для оценки рисков перекрестной контаминации на технологических линиях фармацевтических производств