[Hydrogen effect on the mechanisms of mucosal immunity in patients with COVID-19].

AIM: To study the inhalation of an active form of hydrogen effect to mucosal and system immunity in a rehabilitation program for health workers. MATERIALS AND METHODS: The study involved patients that survived COVID-19 after therapy with inhaled hydrogen for 90 minutes (n=30), and a control group of patients treated according to standard protocol for managing patients that survived COVID-19 during the rehabilitation period (n=30). Biomaterial was carried out in 2 stages: on the first day of the study, before the accepted therapy and on the 10th day of the study. The indicators of humoral and cellular immunity were studied. The levels of secretory immunoglobulin A (sIgA) and IgG were investigated using the method of enzyme-linked immunosorbent assay. Phagocytosis was assessed on a Beckman Coulter FC-500 flow cytometer. Statistical data processing was carried out in the GraphPad Prism 7.00 software using nonparametric methods. RESULTS: It was shown that the phagocytic index (PI) of monocytes in nasal scrapings after inhaled hydrogen treatment did not significantly change relative to the first day of treatment and control, while the PI of granulocytes in nasal scrapings significantly increased relative to the first day by 2.5 times (p=0.000189), as well as relative to the control by 1.1 times (p=0.047410). PI of monocytes in pharyngeal scrapings showed a significant increase relative to the first day of treatment by 2.8 times (p=0.041103), however, did not differ relative to the control. PI of granulocytes of pharyngeal scraping did not differ significantly relative to the first day and control. PI of granulocytes and blood monocytes of the studied group did not change significantly. PI of granulocytes and monocytes of peripheral blood relative to control during therapy did not change. The sIgA level in nasal scrapings significantly increased by 2.9 times, while in pharyngeal scrapings the level of sIgA significantly decreased by 2 times. Сonclusion. We have shown an increase in granulocytes PI in the nasal cavity and oral monocytes, as well as in the level of sIgA in the nasal cavity during therapy with active hydrogen. The data obtained indicate the effectiveness of therapy, which can be used both in the treatment of COVID-19, and in post-COVID syndrome as an additional therapy. The absence of changes in blood parameters, as well as individual links in nasal and pharyngeal scrapings, requires further study to develop ways to overcome treatment tolerance.

[Rational strategy for studying microbiome of the ocular surface of people using hard contact lenses by method of 16S rRNA gene metabarcoding]. / Ratsional'naya strategiya izucheniya mikrobioma glaznoi poverkhnosti pol'zovatelei zhestkikh kontaktnykh linz metodom metabarkodinga po genu 16S rRNK.

The study is based on the hypothesis that high taxonomic diversity of bacteria detectable on the eye surface by molecular genetic methods is attributed to the high level of its contamination by skin microflora. Such contamination would make it problematic to identify the fractions of real ocular surface microbiome, which remains behind the one-percent cut-off threshold adopted in the metagenomic analysis. Hard contact lenses for long-wearing act as a physical filter preventing DNA contamination from random microorganisms, and at the same time providing adhesion to the living cells of bacteria and fungi. To confirm this assumption, a detailed analysis of references was carried out, supplemented by original laboratory research. MATERIAL AND METHODS: The analysis included 16 hard contact lenses obtained from 11 patients with impaired refraction (myopia). Additionally, conjunctival mucosa scrapings were collected from 42 patients. Samples were cross-analyzed by 16S rRNA gene sequencing using 454 GS Junior (Ion Torrent) and Illumina MiSeq platforms. RESULTS: Results obtained by the Illumina platform (analysis of the V3-V4 variable region of the 16S rRNA gene) showed better convergence with the data of culture tests reported in the literature. The major microorganism groups found were: Acinetobacter (39%), Gluconacetobacter (10.8%), Propionibacterium (9.3%), Corynebacterium (9.3%), Staphylococcus (7.2%), Streptococcus (7%), Pseudomonas (4.1%), Micrococcus (3.3%), Yersinia (3%), Chondromyces (2.4%), Serratia (2.3%), and Bacillus (2.1%). Analysis of the samples obtained directly from the mucosa revealed dominance of typical skin-associated microorganisms. CONCLUSION: The present study proposes a contamination-reduction algorithm for microbiological testing of the ocular surface using hard contact lenses for prolonged wearing as a carrier for microbial DNA.