Features of the Humoral Response to Infection, Vaccination, and Revaccination during COVID-19.

IgM and IgG antibodies to the SARS-CoV-2 virus are detected in subjects who have recovered from COVID-19; IgM antibodies persist in a 1/3 of infected subjects up to 12 months from the moment of the disease, while IgG antibodies are present in the vast majority of cases (97%; medium and high levels antibodies were registered in 85% of cases). By the 12th month, 40% of those who recovered still have a very high level of IgG antibodies to the S-protein (>500 BAU/ml). In the feces, urine, and blood serum of patients with long-term persistent IgM antibodies, no coronavirus antigens were detected. After vaccination with the Gam-COVID-Vac vaccine, IgG antibodies to the S-protein are detected in 100% of cases and remain at a high level for 4 months, by the 5-6th month, the level of antibodies decreases. During revaccination, the level of IgG antibodies to S-protein reaches high values earlier than during primary vaccination, and remains high for 4 months (observation period). The blood sera of recovered and vaccinated patients have a high virus-neutralizing activity (at least 1:80), while its level is somewhat higher in recovered patients.

[Determination of calcium metabolism markers concentration in patients with calcium oxalate nephrolithiasis].

THE AIM OF THE RESEARCH: to reveal the relationship of various markers of calcium metabolism (osteopontin (OPN), parathyroid hormone-related protein (PTHrP), vitamin D, parathyroid hormone (PTH)) on the course of urolithiasis (Urolithiasis) in patients with calcium oxalate nephrolithiasis. MATERIALS AND METHODS: 100 people were examined, the following groups were included: group 1 - patients with calcium oxalate primary nephrolithiasis (n=41), group 2 - with calcium oxalate recurrent nephrolithiasis (n=39). Group 3 included conditionally healthy volunteers (n=20). The studies were carried out by the immunoenzymometric ELIZA and biochemical methods using appropriate test systems. RESULTS: in patients with recurrent nephrolithiasis, the serum PTHrP level is 54.6 (25.4-78.2) pg / ml, which is 3.7 times higher than in conventionally healthy individuals; the level of osteopontin is more than 1.5 times higher and amounts to 1.820 (0.991-2.212) pg / ml. In the group of primary nephrolithiasis, the level of PTHrP is 2-2.5 times higher than in conventionally healthy people. In patients with primary nephrolithiasis, the blood calcium level does not correlate with the level of PTHrP in the blood (r=- 0.0173, p> 0.05), as in the group with recurrent nephrolithiasis (r=0.0223, p>0.05). DISCUSSION: in patients with recurrent nephrolithiasis in the preoperative period, the serum levels of osteopontin and PTHrP in the blood serum were higher than in patients who were first diagnosed with urolithiasis, the data obtained can be used as a criterion for predicting the risk of recurrence of urolithiasis in the postoperative period. The blood calcium level does not have a statistically significant relationship with PTHrP, which allows us to assume that PTHrP has other mechanisms of influence on the development of urolithiasis, given the data obtained that the PTHrP level in patients with primary and recurrent nephrolithiasis is higher than in conditionally healthy people. CONCLUSION: Determination of the level of PTHrP and osteopontin in patients with urolithiasis allows predicting the risk of recurrence of urolithiasis at the stage of primary calcium oxalate nephrolithiasis. Determination of the level of PTHrP makes it possible to predict the risks of developing urolithiasis in conventionally healthy individuals, which can be used for targeted prevention of an unfavorable course of urolithiasis by prescribing timely adequate rational therapy and correcting the patients diet. At the same time, no correlation was found between the level of PTHrP and the level of blood calcium in patients with calcium oxalate nephrolithiasis; therefore, further studies of the role of this protein in the pathogenesis of urolithiasis are needed.

Experience of Antiseptic Application for Processing of Rat Lung Biological Matrices.

To select the optimum method for disinfecting scaffolds before recellularization, the effects of octenisept and chlorhexidine at different concentrations on lung biological matrices before and after decellularization were studied by using morphological methods (studies of biomechanical strength of extracellular matrix fibers) and by analyzing chemiluminescence in rats. Chlorhexidine diluted 1 : 10 had the least damage on the matrix properties and to the greatest extent contributed to disinfection of scaffolds for their further storage and experimental studies.

Mathematical Modeling of Open States in DNA Molecule Depending on the Deuterium Concentration in the Surrounding Liquid Media at Different Values of Hydrogen Bond Disruption Energy.

The effect of the deuterium concentration in the surrounding liquid medium on the appearance of open states between the nitrogen bases of a double-stranded DNA molecule was investigated. It is shown that the nature of this effect depends on the magnitude of the energy of the hydrogen bond break.

Changes in the functional activity of mitochondria isolated from the liver of rat that passed the preadaptation to ultra-low deuterium concentration.

The incubation in deuterium-depleted medium of mitochondria isolated from the liver of rats that consumed drinking diet with depleted deuterium (46 ppm) revealed a higher (by 35%) generation of hydrogen peroxide in comparison with the mitochondria (isolated from the liver of rats that consumed drinking diet with 152 ppm deuterium) incubated in medium that contained 152 ppm deuterium. Succinate addition to the reaction system led to an increase in the production of hydrogen peroxide in isolated mitochondria by 44-81%, whereas the difference in the generation of H2O2 between the organelles incubated in mediums 46 and 152 ppm was reduced by 14%. The revealed change in the functional activity of mitochondria suggests the ability of the organism to adapt to the deuterium-depleted drinking diet, which is probably due to the formation of the D/H isotope transmembrane gradient.

Dynamics of the Pro-Oxidant/Antioxidant System Parameters in Wound Discharge and Plasma in Experimental Purulent Wound during Its Technological Liquid Phase Treatment.

The dynamics of the pro-oxidant/antioxidant system of rabbits was studied at the local (in exudate) and systemic (blood) levels during therapy of purulent wounds in liquid medium with the use of a programmed device and the efficiency of the proposed technological method was compared with that of classical methods for the treatment of these wounds. More rapid recovery of the indicators of the pro-oxidant/antioxidant system to physiological values in the postoperative period was observed after treatment by the proposed method (7 days vs. 10 days after standard treatment), these results attest to strengthening of the adaptation potential in laboratory animals. The intensity of free radical oxidation in the exudate decreased by 26.6% in animals treated by the technological method. These data indicated acceleration of the regenerative processes at the local level.

[Experimental development and rationale for a renal decellularization protocol with subsequent comprehensive assessment of the biological scaffold].

Chronic renal failure (CRF) is one of the most challenging problems of contemporary medicine. Patients with chronic renal failure usually need renal replacement therapy as either hemodialysis, peritoneal dialysis or a kidney transplant. The latter is the most promising option for end-stage kidney disease. However, the shortage of donor organs, the complexity of their delivery, the difficulty in finding an immunologically compatible donor and the need for lifelong immunosuppression triggered advances in modern tissue engineering. In this field, the primary priority is focused on developing bioengineered scaffolds with subsequent recellularization with autologous cells. Using such constructs would allow for solving both ethical and immunological problems of transplantation. The aim of this pilot study was to develop a new method of renal decellularization using small laboratory animals. MATERIALS AND METHODS: The study investigated the morphological structure of the obtained decellularized matrix and quantitatively tested DNA residues in the resulting scaffold. We proposed a new biophysical method for assessing the matrix quality using the EPR spectroscopy and conducted experiments on the matrix recellularization with mesenchymal multipotent stem cells to estimate cytotoxicity, cell viability and metabolic activity. RESULTS: The obtained decellularized renal matrix retained the native tissue architecture after a complete removal of the cell material, had no cytotoxic properties and supported cell adhesion and proliferation. CONCLUSION: All the above suggests that the proposed decellularization protocol is a promising method to produce tissue-engineered kidney constructs with possible clinical application in the foreseeable future.

EPR spectroscopy solutions for assessment of decellularization of intrathoracic organs and tissues.

Using EPR spectroscopy it was established that the determination of the concentration of paramagnetic centers in lyophilized tissues allows indirect evaluation of the quality of decellularization of intrathoracic organs (diaphragm, heart, and lungs), since the content of paramagnetic particles in them can serve as a criterion of cell viability and points to the necessity to repeat decellularization. Experiments in rats showed that the EPR spectra of the native thoracic organs contained paramagnetic centers with g-factor values ranging from 2.007 to 2.011 at a concentration of 10(-8) to 6.62 × 10(-7) mol/g of lyophilized tissue, whereas in all decellularized tissues of the same organs paramagnetic particles were not detected.

[Influence of linseed oil and deiterium depleted water on isotopic D/H composition and functional antioxidant defense of the hepatobiliary system in rabbits with carbon tetrachloride intoxication].

The article presents results of studying the influence of linseed oil and drinking diet with a modified isotopic composition with low deuterium content on indicators of prooxidant-antioxidant system during modeling of liver toxicity. The research was performed on 36 rabbits (weighing 3.1-3.5 kg) which were divided into 4 groups. Group 1 consisted of control animals; in group 2, 3 and 4 in rabbits the liver toxicity was modeled by administration of CCl4 (intraperitoneally, in the form of a 50% oil solution, 1 ml per kg bw, 2 times a week for 30 days); nutritional correction using flaxseed oil (0.1 ml per 100 g bw) and drinking diet with deuterium depleted water (50 ppm) was carried out in animals from groups 3 and 4 respectively, for 30 days prior to simulation of toxic hepatitis and more throughout the experiment. Using the method of nuclear magnetic resonance and mass spectrometry the influence of deuterium depleted water on D/H composition of the blood plasma, bile and liver tissues was determined: the deuterium concentration in these biological materials significant decreased. The most significant decrease in the deuterium content (30.2% compared with the control group) was found in bloodplasma in animals from group 4. The study of the state of prooxidant-antioxidant balance of the liver and bile showed oxidative stress at the local level, with the toxic effects of carbon tetrachloride. This was followed by EPR spectroscopy data pronounced increase of the number of paramagnetic centers in the hepatocytes by 5.4, 1.9 and 2.8 fold in animals of 2, 3 and 4 groups, respectively (compared to the indicators of the first group). There was also increase in the intensity of free radical oxidation processes in the bile with a simultaneous reduction of its antioxidant activity, which was significantly less distinct (on average 51.18-59.8%, p<0.05) in animals treated with nutritional correction, indicating that higher functional activity of protective systems involved in recycling prooxidant factors using dietary lipophilic antioxidants and water with low deuterium content. Overall, the results of the present study indicate that existing in the liver and bile autonomous mechanisms of regulation of the state of prooxidant-antioxidant systems are quite sensitive to the effects of antioxidant factors of lipophilic nature and shifts of isotopic D/H gradient, and suggest usefulness of the products that can affect these indicators to increase adaptive capabilities of the organism during intoxication.

[Correction of Metabolic Processes in Rats during Chronic Endotoxicosis using Isotope (D/H) Exchange Reactions].

The effect of isotope exchange reactions (deuterium/protium, D/H) on morphofunctional indices and the state of the antioxidant blood system in rats was studied under physiological conditions and during experimental chronic endotoxicosis of hepatorenal genesis. It was demonstrated that introduction of water with a decreased content of deuterium in the food rations of rats results in a decrease in its concentration in the blood plasma by 32-36% (to 98-106 ppm) and in lyophilized liver, kidney, and heart tissues by 13-17% (to 123-128 ppm). It was noted that it is accompanied by correction of metabolic processes, an increase in the functional activity of nonspecific protection system, and an increase in the body weight growth by the 42nd day in the group of animals that passed (for 14 days) the stage of preliminary adaptation with a change in the D/H ratio in the organism.

[Experimental study of influence of lipophilic products of phytogenic origin on lipid metabolism in rats].

The article presents the results of biochemical evaluation of metabolic effects of lipophilic products of plant origin among which such oils as linseed, black nuts and walnuts oils as well as medicine «Phosphogliv¼ were selected as the most promising ones. The influence of the studied substances on lipid metabolism in experiment on male rats (170­220 g body weight) with modeled acute hepatotoxicity with carbon tetrachloride (that was achieved by subcutaneous injection of 50% oil solution of carbon tetrachloride ­ 0.5 ml/100 g of the body mass once a day during 3 days) has been investigated. Liver function was assessed by triacylglycerols content in the serum, total, esterified and nonesterified cholesterol, cholesterol in the lipoproteins of high, low and very low density, as well as by the nonesterified cholesterol and phospholipids content in the hemolysate of red blood cells. Carbon tetrachloride hepatotoxic damage was accompanied by the development of severe hypercholesterolemia associated both with the increase in total cholesterol and its content in low density lipoproteins alongside the reducing of the cholesterol concentration in high density lipoproteins, resulted in secondary dyslipoproteinemia. Inhibition of the esterification of cholesterol processes as well as the decrease in the triacylglycerols concentration was observed. It is connected with the triacylglycerols endogenous synthesis blocking in the liver, resulted from its toxic damage. It is also confirmed by cholesterol content reducing in the lipoproteins of very low density. In erythrocytes of rats with CCl4 intoxication phospholipid content decreased while the amount of nonesterified cholesterol that is a component of cell membranes, influencing the proteins and lipids diffusion, which reduces the mobility of the fatty acid residues of phospholipids, increased. The injection of the black nuts and walnuts oils as well as flax oil (intragastric injections 0.2 ml daily in the morning before the main feeding from the 7th to the 30th day of the experiment, n=25 in each group) to rats with liver failure induced by carbon tetrachloride, contributed to the partial restoration of liver tissue structure and statistically reliable decrease of lipid metabolism. Decrease in the total cholesterol content by 17.5% in the group of animals treated with linseed oil was observed; LDL cholesterol also decreased under the influence of walnuts and black nuts oils by 36.7 and 40.6% respectively. The increase in the content of phospholipids in erythrocytes of rats when administered by the studied lipophilic products has made it possible to prove the improvement of the cell membranes rheological properties. The results of the study of the influence of linseed, black nuts and walnuts oils as well as medicine «Phosphogliv¼ on animals with hepatotoxicity by CCl4 have proved positive effect of these lipophilic substances on lipid metabolism.

Content of deuterium in biological fluids and organs: Influence of deuterium depleted water on D/H gradient and the process of adaptation.

It is found that consumption of deuterium depleted water reduces not only the content of deuterium in biological fluids but also more than 2 times reduces the D/H gradient value along the line: mixed saliva > blood plasma. The experimental data showed that a physiological solution prepared on deuterium depleted water during induced apoptosis activates the DNA repair system, significantly reducing the number of single-stranded DNA breaks, which, in general, indicates an increase in the efficiency of defensive systems of the cell.

[EXPERIMENTAL FOUNDATION FOR LINSEED AND WALNUT OILS APPLICATION IN GASTROENTEROLOGY].

In the article the influence of the hepatotropic effect of linseed and walnut oils on the lipid composition of the rats' blood serum under CCl4 intoxication has been presented. Lipid metabolism was characterised by the assessment of total cholesterol content in the blood serum, non-etherified cholesterol, cholesterol ethers, cholesterol lipoproteids of high-, low- and very low- density as well as triaclglycerins. In rats with experimental severe liver insufficiency associated with cholesterol increase in low-density lipoproteid fraction alongside its decrease in high-density lipoproteid fraction hypercholesterolemia was progressing. Cholesterol etherification inhibition (by 31.1%) was also observed. The tendency to less intensive disorders (by 1.7-2.0) as well as the tendency to lipid metabolism normalisation in animals have been revealed under the influence of lipophilic substances studied.

[Comparative characteristics of the isotopic D/H composition and antioxidant activity of freshly squeezed juices from fruits and vegetables grown in different geographical regions].

Data presented in this paper reflect changes in antioxidant activity, the content of prooxidant factors and deuterium concentration in freshly squeezed juices from fruits and vegetables grown in different climatic regions (10 samples of juices from wholesale and retail trade network of 8 kinds of vegetables and fruits, 28 manufacturers from 14 countries). Determination of the concentration of deuterium was performed using a nuclear magnetic resonance spectrometer. Total antioxidant activity of fresh juices was determined amperometrically after dilution in 2.2 mM H3PO4 in a ratio of 1:100. Prooxidant performance was evaluated by a maximum and area of flash of chemiluminescence induced by the introduction of 0.3% hydrogen peroxide. It was found that the antioxidant activity of fresh juice from fruits and vegetables grown within the same climatic region can differ by several times. In this case, most of the fruits and vegetables of russian producers were not inferior, than antioxidant activity of the fresh juices from the same plant products grown abroad. It should be noted that the indicators of the antioxidant activity of fresh juice from Russian pears exceeded this indicator of all fresh juices from pears, imported from Argentina, South Africa and the United States of America by 21.1, 30.4 and 32.7%, respectively. In assessing the prooxidant properties of fresh juices should be noted the almost complete absence of factors with prooxidant nature only in 36% of the studied fresh juices, whose maximum performance and area of flash of chemiluminescence were less than 0.1%, including a pear and apple juices from the russian production. It should be noted that the area of chemiluminescence of the juice from potatoes, grown in Russia, was at 103.1 and 115.2% lower than in juice obtained respectively from potatoes produced in Israel and Egypt (p<0.05), indicating a higher safety of consumption of potatoes produced in Russia. When studying--the isotopic D/H composition of fresh juices it was found that the highest deuterium content was in the juice from the pears, imported from Argentina (deltaD = -72% per hundred), while the lowest concentration of deuterium was observed in the juice from the Egyptian potatoes (delta = -358% per hundred). In general, significantly lower deuterium content was determined in fresh juices made from potatoes and cabbage grown in different countries, in comparison with other fresh juices from fruits and vegetables. The smallest range of differences in the isotopic D/H was composed in freshjuices from tomato, pomegranate and oranges of Turkish manufacturers (deuterium concentration ranged in them from -221 to -214% per hundred), that can be used to confirm the geographical origin of fruits and vegetables grown in Turkey. The data reflecting the antioxidant activity, the content of prooxidant factors and deuterium concentration in the juices, allow us to recommend the latter as additional criteria when assessing the quality of food products.

[Influence of deuterium depleted water on freeze-dried tissue isotopic composition and morphofunctional body performance in rats of different generations].

The influence of deuterium depleted water on the body of different rats generations was investigated in physiological conditions. As a result of this study it was established that the most significant and rapid reduction in D/H equilibrium was observed in plasma (by 36.2%), and lyophilized kidney tissues (by 15.8%). Less pronounced deuterium decrease was characteristic of liver tissue (9.3%) and heart (8.5%). Stabilization of the isotopic exchange reaction rate was fixed in the blood and tissues of rats, starting from the second generation. At the same time when deuterium depleted water (40 ppm) was used in dietary intake, the change in morphological and functional parameters in laboratory animals associated with the processes of adaptation to the effects of substress isotopic D/H gradient was also noted. The study shows that modification of:only drinking water intake regime can't significantly change the deuterium content in tissues of metabolically active organs, because of the concurrent deuterium receipt in food substances of plant and animal origin.

[Comparative evaluation of antioxidant activity and content of prooxidant factors in different classes of foods].

By using the biophysical methods (chemiluminescence, amperometry) in laboratory in vitro experiments it was demonstrated that the study of antioxidant and pro-oxidant activities of different food groups allows to perform a preliminary assessment of their pro-oxidant-antioxidant capacity. It have been shown that some food prevails ability to exert pro-oxidant effects (in vitro) due to the short-term induction of free radical oxidation. Thus, among the fresh juices the increase of the maximum of flash chemiluminescence has been detected in avocado (1080, 89%) and pearjuices (136,33%), whereas the lowest ability to enhance the intensity of free radical processes has been marked for pomegranate (1,63%), orange (9, 68%) and apples juices (12, 84%). Among milk products it has been marked for sour milk (9, 06%) and yogurt (15, 11-16,02%), that allows the use of the past to correct pro-oxidant-antioxidant balance diet for people with potential danger gain peroxide processes, such as special physiological states, sport endurance, mental and emotional overload. The ability to increase the intensity of free radical oxidation have been also identified for snacks, especially buns, biscuits, bread sticks, showing the risk of formation of oxidative stress in the body during their prolonged use, particularly under the above described conditions. In some cases, foods (processed cheese and cheese curds) showed dominance factors sustained oxidative effect (in 2,1-20,7%), that indicates the possibility of an imbalance in the pro-oxidant-antioxidant system after its prolonged use in the diet, even in small quantities, especially in individuals with a reduced level of antioxidant potential of the nonspecific defense system. Investigation of antioxidant activity of foods revealed significant predominance of reducing equivalents in all freshly squeezed and some packaged fruit juices, as well as dairy products, indicating their possibility to increase the capacity of reducing components of nonspecific protection system. The presence in a number of products used for snacking (chips, puffed rice) of sufficiently high levels of antioxidant activity demonstrates the content of substances that act as proton donator having significant reducing ability. It is sufficient for high energy value of such products, indicating on the possibility of involvement of their recovery factors in plastic processes with subsequent enhancement, such as lipogenesis, that may be a prerequisite for the development of obesity, atherosclerosis and otherpathological processes. Using an integrated approach will enable a timely and appropriate to correct the ratio of pro- and antioxidant indicators of diet in order to improve the adaptive capacity of the organism in a particular physiological or pathological conditions involving oxidative metabolism disorders.

[Influence of deuterium depleted water on the organism of laboratory animals in various functional conditions of nonspecific protective systems].

The influence of deuterium depleted water with the modified isotope composition on an organism of animals is studied in physiological conditions and development of chronic endogenous intoxication of hepatorenal genesis. The influence of this water on isotope composition of plasma and tissues (the liver and kidneys) in laboratory animals is shown. The impact of this water on biochemical indicators (AST, ALT, alkaline phosphatase, creatinine, bilirubin) and dynamics in body weight of laboratory animals within 42 days is established. As a result of studies the possibility of the preventive use of deuterium depleted water for correction of metabolic processes is shown in various conditions of the functional system of the body's detoxification.

[Determination of deuterium concentration in foods and influence of water with modified isotopic composition on oxidation parameters and heavy hydrogen isotopes content in experimental animals].

The article presents the results of the study of the deuterium (D) content in food products as well as the influence of deuterium depleted water (DDW) on the concentration of heavy hydrogen isotopes in the blood and lyophilized tissues of rats. The most significant difference in the content of D was found between potato and pork fat, which indexes the standard delta notation (δ) D in promille, related to the international standard SMOW (Standard Mean Ocean of Water) amounted to -83,2 per thousand and -250,7 per thousand, respectively (p<0,05). Among the investigated samples of water deuterium concentration ranged from -75,5 per thousand (Narzan) to +72,1 per thousand (Kubai), that indicates the ability of some food products to increase the concentration of heavy hydrogen atoms in the body. The data obtained in the experimental modeling of the diet of male Wistar rats in the age of 5-6 mo (weight 235 ± 16 g) using DDW (δD = -743,2 per thousand) instead of drinking water (δD = -37,0 per thousand) with identical mineral composition showed that after 2 weeks significant (p <0,05) formation of isotopic (deuterium-protium, D/H) gradient in the body is possible. Changing the direction of isotopic D/H gradient in laboratory animals in comparison with its physiological indicators (72-127 per thousand, "plasma>>tissue") is due to different rates ofisotopic exchange reactions in plasma and tissues (liver, kidney, heart), which can be explained by entering into the composition of a modified diet of organic substrates with more than DDW concentration D, which are involved in the construction of cellular structures and eventually lead to a redistribution of D and change direction of D/H gradient "plasma<

[Comparative characteristics of antioxidant capacity and energy content of some foods].

The paper presents a comparative evaluation of antioxidant capacity and energy values of different foods groups in order to identify the most efficient combinations for correction of metabolic disorders associated with an imbalance in antioxidant system. In study integral method for determining of antioxidant and energy indicators (patent No 2,455,703) has been used. It has been revealed that the highest antioxidant-energy capacity (AE) of fresh juices has a pomegranate juice (AE = 3895.9 +/- 241.4 mg/L x kJ(-1)), other fresh juices inferior to him on this indicator: grenade>orange>lemon=apple> pomelo > mandarin > persimmon > kiwi > pears > avocado. Among dairy products the highest AE belongs to boiled fermented milk--"ryazhenka" (AE = 40.9 +/- 2.7 mg/L x kJ(-1)), other dairy products can be placed in line with index AE: ryazhenka ==>kefir > yogurt. Most of fresh juices were significantly superior to antioxidant-energy potential of other foods. Despite the fact that dairy products AE were lower than AE of some juices, they were much superior to AE values of fastfood products (biscuits, potato chips, popcorn). This demonstrates need to reduce the quota of fast foods in the diet to prevent the risk of reduction potential of the endogenous antioxidant system.

[The effect of water with modified isotope content on the parameters of free radical oxidation in vivo].

With the use of nuclear magnetic resonance we investigated the effect of consumption of water with the modified isotope content on the composition of deuterium in the blood, assessed the state of pro-oxidant-antioxidant system in the blood and lyophilized tissues (liver, kidneys) under prolonged oxidative stress. Possible mechanisms of direct and indirect antioxidant effects of the water with modified isotope content and the perspectives of its use for nutritional correction of abnormalities of oxidative metabolism during special physiological conditions and in clinical practice are discussed.