ISSN Print 2713-2757    ISSN Online 2713-2765
SCIENTIFIC AND PRACTICAL REVIEWED JOURNAL OF FMBA OF RUSSIA

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The specifics of individual immune reactions after COVID-19 have not been studied sufficiently. This study aimed to describe the changes in indicators of cellular and humoral levels of immunity after COVID-19, and gage general trends and individual characteristics. We sampled blood of 125 unvaccinated COVID-19 patients (29 men and 96 women, median age 53 years) 1 to 4 months after recovery, and determined the relative content of T-lymphocytes (CD3+), B-lymphocytes (CD19+), and cells with late activation markers (CD3+HLA–DR+) in them using flow cytometry. With the help of ELISA, we have registered the level of circulating immune complexes, which can be medium molecular weight (CICmed) and low molecular weight (CIClow), and the content of antibodies to SARS-CoV-2. In the mild course group, significant differences from the normal values (p < 0.001) were found for T cells (growth, 74.4 ± 1.2% vs. 68.6 ± 1.1%) and B cells (decline, 10.2 ± 0.7% vs. 13.9 ± 0.9%). In the moderately severe course and severe course groups, the level of CD3+HLA–DR+ lymphocytes was increased (7.7 ± 0.4% and 15.7 ± 2.5%, respectively, versus 3.9 ± 0.8% in the control group; p < 0.01). All the examined patients had high levels of CIClow (2.6-2.9-fold increase) and CICmed (1.6–1.8-fold increase). The protective level of antibodies to SARS-CoV-2 above 150 BAU/ml was registered in about 50% of the mild group participants, 75% of the moderately severe group members, and 100% of patients who had the disease in a severe form. We detected no connections between immune disorders and clinical features of the course of the disease and the period thereafter, with the exception of abdominal syndrome peculiar to the acute stage of the disease. The article also describes a clinical case of detection in the early post-COVID-19 period of a pathological clone characteristic of B cell chronic lymphocytic leukemia, and its subsequent disappearance and normalization of the immunophenotype as registered during a follow-up 1.5 years after recovery. The persistent immunological shifts should be taken into account when assessing the risks of reinfection and possible complications.
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Vitamin D deficiency that remains non-compensated for a long time is associated with high risk of rickets in children and osteomalacia in adults, myopathies and low-energy fractures, as well as secondary hyperparathyroidism (SHPT). SHPT represents one of the main mechanisms, through which vitamin D deficiency can contribute to pathogenesis of low-energy fractures. The study was aimed to assess the calcium and phosphorus metabolism state and the bone tissue metabolism markers in highly trained athletes with SHPT, as well as the prevalence of SHPT in elite sports. The study involved 527 young athletes aged 12–18 years (average age 15.2 years) doing 32 sports. The group with SHPT included 16 children (11 girls and 5 boys) with the average age of 15.0 years. The control group with normal levels of parathyroid hormone consisted of 511 children (254 boys and 273 girls) with the average age of 15.2 years. The studied subgroups were matched by age (p = 0.678). Girls predominated in the group with SHPT (р = 0.02). SHPT associated with vitamin D deficiency was revealed in 3% of young highly trained athletes, it was more prevalent among girls. The SHPT development does not result in alteration of the calcium and phosphorus metabolism indicators, however, it is accompanied by the increase in bone resorption markers, β-CrossLaps and total alkaline phosphatase. Many aspects related to vitamin D deficiency in SHPT are currently poorly understood, and there are no clinical guidelines on the cholecalciferol replacement therapy. Large-scale clinical trials are required to determine the optimal threshold values of 25(ОН)D3 and the powerful and effective treatment regimens for young athletes having SHPT associated with vitamin D deficiency.
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Toxic effects of the myeloablative cyclophosphamide (CP) doses include damage to the gastrointestinal tract. This is manifested by gastrointestinal stasis, cytostatic drug-induced damage to the small intestinal mucosa, and acute gut-derived endotoxemia. The study was aimed to identify causal relationships between gastrointestinal stasis, enterocytopenia, and acute gut-derived endotoxemia in the rat model of the CP myeloablative conditioning. We assessed the effects of the intragastrically administered 0.48 М sodium bicarbonate (NaHCO3) solution or the 0.1 М hydrochloric acid (HCl) solution on the indicators of gastrointestinal stasis, enterocytopenia, portal blood levels of endotoxin, ammonia, urea, and urinary indican excretion. The stomach overfilled with chyme, decreased alkaline phosphatase and cholinesterase activity in the small intestinal tissues, 4.4-fold increased endotoxin levels, 4.6-fold increased urea levels, twofold increased portal blood plasma creatinine levels, and twofold increased urinary indican excretion were observed three days after intravenous administration of CP in a dose of 390 mg/kg. Intragastric administration of NaHCO3 or HCl partially prevented gastric stasis, but not acute gut-derived endotoxemia. Administration of NaHCO3, not HCl, prevented enterocytopenia in the duodenum. Acute gut-derived endotoxemia resulted mainly from the more intense release of the cecal microflora waste products into blood. Testing the use of sodium bicarbonate intragastric administration combined with the enteral detoxification and/or options for suppression of colonic microflora vegetation for prevention of the myeloablative cytostatic therapy complications is promising.
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Bone-seeking radionuclides, in particular 89,90Sr, could get into the environment in the course of various anthropogenic radiation incidents. From there they enter a human body with food and water. This leads to red bone marrow (RBM) internal exposure. These elements were present in the composition of radioactive releases into the Techa River in 1950s, and are the major source of RBM exposure for the residents of the riverside settlements. RBM dose estimation relies on dosimetric modeling which comprises the development of 3D computational phantoms of the skeleton parts. By imitating the energy transfer in these phantoms, the conversion coefficients from the radionuclide activity in a bone to the dose rate in RBM are evaluated. The given study is yet another step in the research aimed at the elaboration of a set of computational phantoms of the skeleton for people of various age. The objective is to develop a computational phantom of a skeleton of a 10-year-old child to estimate dose to RBM due to incorporated beta-emitters. Original SPSD (stochastic parametric skeletal dosimetry) approach was used to create the phantoms. According to this method the skeleton sites containing RBM were divided into smaller segment of simple geometric shape, for which voxel phantoms were generated. The parameters for phantom generation were based on published research data. They included^ linear dimensions of bones, thickness of the cortical layer, characteristics/properties of the bone micro-architecture, density and chemical composition of the modelled media and the percentage of RBM content in bones. Generated computational phantom of the skeleton sites with active hematopoiesis of a 10-year-old child consists of 38 phantom-segments. Linear dimensions of the segments were from 3 to 88 mm, cortical layer thickness: 0.2–2.2 mm.
VIEWS 432

Popular articles

Today, the prospect of long-term interplanetary missions becomes relevant, that is why it is necessary to understand the changes in the cardiovascular system (CVS) that would occur in hypomagnetic environment. The study was aimed to assess the changes in the CVS mechanisms underlying formation of heart rate variability and bioelectric processes in the myocardium under conditions the 350-, 650-, and 1000-fold reduced Earth’s magnetic field. The experiment (2023) involved 6 male volunteers aged 26–37 years, in whom electrocardiography was continuously performed throughout 32 h. The data obtained were assessed by cluster analysis and analysis of variance. It was found than male volunteers, who belonged to the group showing predominance of parasympathetic effects, had enough functional reserve for critical values (exposure to the up to 1000-fold reduced magnetic field). In volunteers showing predominance of sympathetic modulatory effects, the adaptive response maintenance was ensured by the metabolic regulatory circuit. In this group, the response to the reduced magnetic field exposure was quite pronounced at the threshold of its 350-fold reduction. Our pilot experiment reflecting the effect of the reduced Earth’s magnetic field on the CVS is crucial for development of the concept of further experimental exposures related to magnetic field reduction benefiting space physiology and medicine.
VIEWS 513
The understanding of the exposure effects on the human health could be improved by analyzing the influence of the chronic low dose rate exposure on the senescence of the immune system cells. It will also help to develop the measures aimed at the mitigation of the adverse effects. The objective of the study is to investigate the influence of the chronic low dose rate exposure on the senescence of the immune system cells using the cytogenetic markers. In the course of the research the authors evaluated the cellular senescence markers — genome instability and telomere depletion — in T-lymphocytes of the individuals exposed in the Southern Urals (exposure doses were 0.001 Gy — 4.7 Gy, the age of examined people was 40–89 years). The data analysis has demonstrated that the effect of chronic exposure on the T-cell senescence was indirect. Unstable chromosome aberrations occurred statistically significantly more frequently in exposed people aged 40–59 years (p = 0.012). Frequency of lymphocytes with micronuclei in exposed individuals differed in men and women (p = 0.001). Statistically significant decrease in the telomere length was revealed (for the chromosome arms 1q, 3p, 3q, 20p, 20q, 13q, 15p, 22q (p < 0.05); 19p, 21q (p < 0.01)).
VIEWS 489