[Participation of melatonin in regulation of blood oxygen-transport function in oxidative stress induced by injection of lipopolisaccharide]

[Features of ozone effect on the oxygen-dependent blood processes under hypercapnia conditions]

The aim of this work is to study of ozone effect on blood oxygen-dependent processes under hypercapnia conditions. The studied blood samples are pretreated with a hypercapnic gas mixture followed by the addition of ozonized isotonic sodium chloride solution (with an ozone concentration of 6 mg/l), as well as gaseous transmitters donors, nitroglycerin and sodium hydrosulfide. It has been established that hypercapnia enhanced the ozone effect on the blood oxygen transport function and was characterized by the oxyhemoglobin dissociation curve shift to the right, also increased hydrogen sulfide synthesis and absence of changes in the nitrates/nitrites concentration. Under these conditions nitroglycerin and sodium hydrosulfide did not change the parameters of the blood gas transport function, but increased the level of nitrate/nitrite and hydrogen sulfide. Preliminary hypercapnia does not eliminate the activating effect of ozone on the free radical oxidation processes, and the addition of the applied gaseous transmitter donors does not contribute to the regulation of the studied parameters.

Melatonin effects on sleep quality and outcomes of COVID-19 patients: An open-label, randomized, controlled trial

This trial aims to evaluate the effectiveness of adding melatonin to the treatment protocol of hospitalized coronavirus disease 2019 (COVID-19) patients. This was an open-label, randomized controlled clinical trial in hospitalized COVID-19 patients. Patients were randomized into a treatment arm receiving melatonin plus standard care or a control arm receiving standard care alone. The trial's primary endpoint was sleep quality examined by the Leeds Sleep Evaluation Questionnaire (LSEQ). The trial's secondary endpoints were symptoms alleviation by Day 7, intensive care unit admission, 10-day mortality, white blood cell count, lymphocyte count, C-reactive protein status, and peripheral capillary oxygen saturation. Ninety-six patients were recruited and allocated to either the melatonin arm (n = 48) or control arm (n = 48). Baseline characteristics were similar across treatment arms. There was no significant difference in symptoms on Day 7. The mean of the LSEQ scores was significantly higher in the melatonin group (p < 0.001). There was no significant difference in laboratory data, except for blood oxygen saturation, which has improved significantly in the melatonin group compared with the control group (95.81% vs. 93.65% respectively, p = 0.003). This clinical trial study showed that the combination of oral melatonin tablets and standard treatment could substantially improve sleep quality and blood oxygen saturation in hospitalized COVID-19 patients.

[Prooxidant-antioxidant balance depending on endothelial nitric oxide synthase G894T polymorphism]

The aim of the study was to assess the prooxidant-antioxidant balance depending on endothelial nitric oxide synthase G894T polymorphism. The frequency distribution of alleles and genotypes of G894T polymorphism, nitrite concentration, hydrogen sulphide, lipid peroxidation products (diene conjugates, malonic dialdehyde), antioxidants (reduced glutathione, catalase, ceruloplasmin, retinol) were determined in venous blood of healthy males. The incidence of the GG genotype was 49.1%, GT - 44.2%, TT - 6.7%. The level of malonic dialdehyde in erythrocytes with the GG genotype is 16.8% lower than in the genotype GT. The concentration of hydrogen sulphide in the blood with the GG genotype was 27.5 [18,2; 32,5] mM, GT - 28.6 [22.9; 33.8] mM, TT - 36.3 [33.8; 42.5] mM. The content of total nitrites in plasma with the GG genotype was 10.4 [9,0; 12,5] mM, GT - 10.4 [8.9; 11.8] mM, TT - 9.4 [8.8; 9.8] mM. The genotype GG causes a lower level of malonic dialdehyde in comparison with the heterozygous genotype. The G894T polymorphism allele T is associated with a low content of total nitrites in the plasma and a high concentration of hydrogen sulfide. The data obtained suggest that if the oxygen supply of the organism is impaired, the endothelial nitric oxide synthase G894T polymorphism may be important for the oxidative stress development.