The review presents modern views about the role of oxidative stress reactions in the pathogenesis of types 1 and 2 diabetes mellitus and their complications based on the analysis of experimental and ...clinical studies. The sources of increased ROS generation in diabetes are specified, including the main pathways of altered glucose metabolism, oxidative damage to pancreatic β-cells, and endothelial dysfunction. The relationship between oxidative stress, carbonyl stress, and inflammation is described. The significance of oxidative stress reactions associated with hyperglycemia is considered in the context of the “metabolic memory” phenomenon. The results of our studies demonstrated significant ethnic and age-related variability of the LPO—antioxidant defense system parameters in patients with diabetes mellitus, which should be considered during complex therapy of the disease. Numerous studies of the effectiveness of antioxidants in diabetes mellitus of both types convincingly proved that antioxidants should be a part of the therapeutic process. Modern therapeutic strategies in the treatment of diabetes mellitus are aimed at developing new methods of personalized antioxidant therapy, including ROS sources targeting combined with new ways of antioxidant delivery.
The study involved 271 patients (132 men and 139 women) with moderate COVID-19. Superoxide dismutase (SOD) activity in erythrocytes was measured spectrophotometrically. In total group of patients ...(divided into age groups of 18-35, 36-45, 46-60, and 61-90 years), higher SOD activity was found in the 18-35 age group in comparison with the groups 46-60 years (
p
<0.01) and 61-90 years (
p
<0.05). Then, the groups were additionally divided by sex. In men, no differences in enzyme activity were found between the age groups. In women of early reproductive age, SOD activity was higher than in groups 36-45, 46-60, and 61-90 years. The sex differences consisted in higher SOD activity in women aged 18-35 years in comparison with men of this age. These data should be taken into account when choosing the tactics of therapy for patients with moderate COVID-19 course.
The study involved 138 women aged 45-60 years in perimenopause (
n=
55) and postmenopause (
n=
83) with insomnia (main groups) and without it (control). The levels of reduced (GSH) and oxidized ...(GSSG) glutathione and glutathione peroxidase activity were determined in erythrocytes; activities of glutathione S-transferase and glutathione reductase were measured in blood serum. The differences with the control groups were found only in perimenopause: higher glutathione reductase activity and reduced GSSG level and GSH/GSSG ratio in women with insomnia (
p
<0.05). The results of the comparative analysis between the main groups showed lower glutathione reductase activity, increased GSSG level, and a decrease the GSH/GSSG ratio in the postmenopausal period compared with the perimenopause (
p
<0.05). These results can be used in choosing the tactics for complex therapy of insomnia in menopausal women to correct free radical homeostasis and prevention of oxidative stress.
We performed an immunohistochemical study of MT
2
melatonin receptor expression in the liver of C57BL/6 mice with modeled light-induced functional pinealectomy and after melatonin administration by ...the indirect avidin-biotin peroxidase ABC method. The animals were kept for 14 days under constant lighting. Intragastric administration of melatonin in physiological doses (1 mg/kg body weight for 14 days) to mice with light-induced functional pinealectomy resulted in a 2-fold increase in the relative expression area of MT
2
receptors in liver cells in comparison with that in animals kept under standard lighting conditions, 24-h lighting for 14 days, or 24-h lighting receiving placebo (intragastric administration of 200 ml distilled water). Melatonin treatment had practically no effect on MT
2
staining intensity. Our results attest to the important role of MT
2
receptors in melatonin synthesis disorders and can serve as the basis for the development of therapeutic strategies aimed at melatonin receptors.
The indicators of spermatogenesis and the state of LPO and antioxidant protection in men with pathozoospermia after COVID-19 were assessed before and after treatment an antioxidant complex. Blood ...plasma served as the material for biochemical studies. In the examined patients, the parameters of spermatogenesis, as well as blood concentration of LPO components (diene conjugates and TBA-reactive substances) were analyzed. The total antioxidant activity of the blood was determined as an indicator characterizing the total activity of LPO inhibitors and determining its buffer capacity. In patients recovered from COVID-19, an increase in spermatogenesis disorders and shifts towards the predominance of prooxidant factors were observed. After a course (1 month) of antioxidant complex, patients showed increased sperm motility, decreased leukocyte count in the ejaculate, and restored balance in the prooxidant—antioxidant system towards antioxidant components. The effectiveness of correction of post-COVID disorders largely depends on the degree of damage to the structure and function of cell membranes caused by oxidative stress. The use of the antioxidant complex is a promising option, because it reduces the level of LPO, enhances antioxidant protection of the body, and also normalizes some parameters of spermatogenesis.
The use of silver in various spheres of life and production leads to an increase in environmental pollution, including soil. At the same time, the environmental consequences of silver pollution of ...soils have been studied to a much lesser extent than those of other heavy metals. The aim of this study is to estimate silver ecotoxicity using the soil state biological indicators. We studied soils that are significantly different in resistance to heavy metal pollution: ordinary chernozem (Haplic Chernozems, Loamic), sierosands (Haplic Arenosols, Eutric), and brown forest acidic soil (Haplic Cambisols, Eutric). Contamination was simulated in the laboratory. Silver was introduced into the soil in the form of nitrate in doses of 1, 10, and 100 mg/kg. Changes in biological parameters were assessed 10, 30, and 90 days after contamination. Silver pollution of soils in most cases leads to deterioration of their biological properties: the total number of bacteria, the abundance of bacteria of the genus Azotobacter, the activity of enzymes (catalase and dehydrogenases), and the phytotoxicity indicators decrease. The degree of reduction in biological properties depends on the silver concentration in the soil and the period from the contamination moment. In most cases, there is a direct relationship between the silver concentration and the degree of deterioration of the studied soil properties. The silver toxic effect was most pronounced on the 30th day after contamination. In terms of their resistance to silver pollution, the studied soils are in the following order: ordinary chernozem > sierosands ≥ brown forest soil. The light granulometric composition of sierosands and the acidic reaction of the environment of brown forest soils, as well as the low content of organic matter, contribute to high mobility and, consequently, high ecotoxicity of silver in these soils. The regional maximum permissible concentration (rMPC) of silver in ordinary chernozem (Haplic Chernozems, Loamic) is 4.4 mg/kg, in sierosands (Haplic Arenosols, Eutric) 0.9 mg/kg, and in brown forest soils (Haplic Cambisols, Eutric) 0.8 mg/kg.
The aim of the study was to modify a simple and widely used spectrophotometric assay for MAO activity evaluation with 2,4-dinitrophenylhydrazine. A modified procedure includes molar absorption ...coefficients of 2,4-DNP-hydrazone benzaldehyde and 2,4-DNP-hydrazone 5-hydroxyindolylacetaldehyde as 2.3 × 104mol−1l cm−1 and 1.0 × 104 mol−1l cm−1, respectively. Such an approach allows to express specific enzyme activity as nmol product formed/min/mg protein.
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•Determination of MAO activity has a wide range of applications.•The DNPH spectrophotometry is sensitive and simple method for detect MAO activity.•Enzyme activity is evaluation of the reaction product formed per mg of protein per minute.
The development of regional or local maximum permissible concentration (MPC) for a pollutant in the soil requires the field or laboratory simulation of pollution. The experimental design should ...include the control (uncontaminated soil with the background concentration of the pollutant) and at least three treatments with different pollutant concentrations in the range between 2 and 10 background values. Experiments are performed in at least three replicates. Soil samples are taken 30 days after contamination. In each soil sample, six biological parameters are determined: total bacterial abundance,
Azotobacter
abundance, catalase activity, dehydrogenase activity, cellulolytic activity, and radish root length. Analyses are made in at least six replicates. From these biological parameters, the integrated biological index (IBI) of soil is calculated. For this purpose, the value of each parameter in the uncontaminated soil is taken as 100%, and its values in the contaminated soils are expressed as percentages. The mean values of six parameters for the contaminated treatments are determined. The obtained IBI values are expressed in percentages of the background. Then, a regression equation describing the decrease in IBI values as a function of pollutant concentration in the soil is derived. The pollutant concentration corresponding to the IBI decrease by 10% of the control, which indicates a disturbance of the holistic biogeocenotic functions of soil, is calculated from this equation.
We analyzed the blood concentration of pro- and anti-inflammatory cytokines in the ovarian vein basin area in women of the reproductive age with primary pelvic varices. Increase in the disease ...severity was accompanied by a significant increase in proinflammatory cytokines (TNFα, IL-1β, IL-2, IL-6, and IL-8) and the proinflammatory index (IL-6/IL-10), whereas anti-inflammatory cytokine production changed ambiguously (increase of IL-4 at stage I, decrease of IL-10 at stage II, significant decrease of IL-4 and IL-10 at stage III). Control of these changes in female patients should probably be an important component of treatment measures and prevention of morphofunctional disorders occurring at disease progression, in particular at stage III of the disease.
The paper is a theoretical study of mechanically activated processes in tribocontact, which lead to the formation of a lubricating film between rubbing bodies. The adhesive aspect of tribofilm ...formation is considered using the condition of the mechanical activation of the friction surface. This condition is satisfied when the adhesion energy becomes greater than the cohesion energy. The Hamaker constant is used to describe not only the adhesive interaction during friction, but also the amount of matter transferred when the mechanical activation condition is met. It is shown that the adhesive effect decreases with the second power of the distance from the friction surface. A relationship is derived that relates tribological characteristics to the Hamaker constant as the fundamental characteristic of the material. It is shown how the friction coefficient in the steady-state regime depends on the counterbody material and the antifriction transfer film material. Numerical results are compared to experimental data.
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