[Changes in the Genome of the Tick-Borne Encephalitis Virus during Cultivation].

The tick-borne encephalitis virus (TBEV) strain C11-13 (GenBank acc. no. OQ565596) of the Siberian genotype was previously isolated from the brain of a deceased person. TBEV C11-13 variants obtained at passages 3 and 8 in SPEV cells were inoculated into the brains of white mice for subsequent passages. Full genome sequences of all virus variants were analyzed by high-throughput sequencing. A total of 41 single nucleotide substitutions were found to occur mainly in the genes for the nonstructural proteins NS3 and NS5 (GenBank MF043953, OP902894, and OP902895), and 12 amino acid substitutions were identified in the deduced protein sequences. Reverse nucleotide and amino acid substitutions were detected after three passages through mouse brains. The substitutions restored the primary structures that were characteristic of the isolate C11-13 from a human patient and changed during the eight subsequent passages in SPEV cells. In addition, the 3'-untranslated region (3'-UTR) of the viral genome increased by 306 nt. The Y3 and Y2 3'-UTR elements were found to contain imperfect L and R repeats, which were probably associated with inhibition of cellular XRN1 RNase and thus involved in the formation of subgenomic flaviviral RNAs (sfRNAs). All TBEV variants showed high-level reproduction in both cell cultures and mouse brains. The genomic changes that occurred during successive passages of TBEV are most likely due to its significant genetic variability, which ensures its efficient reproduction in various hosts and its broad distribution in various climatic zones.

[Genetic Variability of Tick-Borne Encephalitis Virus Genome 5'-UTR from Northern Eurasia].

This paper reports the analysis of the nucleotide sequences of the 5'-untranslated region (5'-UTR) of tick-borne encephalitis virus (TBEV) genomic RNA isolated from 39 individual taiga ticks collected in several regions of Northern Eurasia. The sequences of 5'-UTRs of the Siberian and Far East TBEV genotypes were 89% and 95% identical to the prototype strains (Zausaev and 205), respectively. The detected nucleotide substitutions were typical for these two TBEV genotypes, which made possible unambiguous identification. Both conservative and variable motifs were detected in the 5'-UTR RNA. The B2, C1, and C2 elements of the Y-shaped 5'-UTR structure and the presumable viral RNA-dependent RNA-polymerase binding site were the most variable. The A2, CS A, CS В elements as well as the start codon were conservative. Interestingly, five substitutions in the 5'-UTR C1 variable element of the TBEVs isolated in different geographical regions were strictly conservative, while 11 different substitutions were detected in this element among the laboratory TBEV variants. A little less that a third of all nucleotide substitutions were mapped outside the main elements of the Y-shaped structure. In general, nucleotide substitutions were localized to stem structures, not being found in the hairpin regions of the TBEV 5'-UTR. The results indicated significant variability of the genomic RNA 5'-UTR in the TBEV laboratory strains and field isolates obtained from different geographical regions. It has been suggested that genetic variability of 5'-UTR is characteristic of the TBEV genome 5'-UTR organization and may serve as a structural basis for virus efficient replication in various avian, mammalian, and ixodic tick cells.

Detection of SARS-CoV-2 RNA in nasopharyngeal swabs from COVID-19 patients and asymptomatic cases of infection by real-time and digital PCR.

In this work we tested two reagent kits developed by us for detecting SARS-CoV-2 RNA using a fragment of the ORF1ab gene in digital PCR and real-time PCR formats. Data were obtained on the detection of SARS-CoV-2 virus RNA in nasopharyngeal swabs of patients with COVID-19 and asymptomatic carriers. The developed reagent kits provided 100% sensitivity and a detection limit of 103 GE / ml for qPCR, and at least 200 copies / ml of viral RNA when performing digital PCR. These methods were tested using a panel of 1,328 samples collected from patients with suspected COVID-19 at the beginning of 2020 in the Russian Federation. It has been shown that dPCR is more sensitive and can be used to analyze samples with low viral load, including those from patients without clinical symptoms. dPCR significantly improves the accuracy of laboratory research and significantly reduces the number of false negative results in the diagnosis of SARS-CoV-2. Determination of the concentration of SARS-CoV-2 RNA in patients with different clinical course of the disease showed that the concentration of viral RNA can sharply decrease in the first days of the disease. A low concentration of viral RNA in samples from patients is also characteristic of asymptomatic disease. Digital PCR provides a higher detection rate for asymptomatic cases, which is approximately 75% of those infected, as opposed to 45% for real-time PCR. The results obtained on the use of the digital PCR method for detecting SARS-CoV-2 RNA showed that this method is especially suitable for detecting RNA in case of its low concentration in contacts, as well as for monitoring changes in viral load in convalescent patients.

[Treatment of gastric ulcer associated with Helicobacter pylori with ronkoleukine under outpatient conditions].

AIM: To determine clinicoimmunological and microbiological efficacy of ronkoleukine in the treatment of Helicobacter pylori-associated gastric ulcer (GU). MATERIAL AND METHODS: A total of 108 H. pylori-associated GU were randomized into two groups. Patients of group 2 received standard 3 or 4 component therapy including proton pump inhibitor and two antibiotics (amoxicillin and clarithromycin). Patients of group 1 received the same treatment but antibiotics were replaced for recombinant interleukine-2 ronkoleukine (Biotech, Russia) which was delivered via gastroscope and injected submucously along the periphery of the ulcer defect in 4-6 points in a dose 0.1 mg; 0.4 mg of the drug was simultaneously injected intravenously. The procedure was made 3 times with a 72 hour interval. RESULTS: One month after the treatment H. pylori eradication was 81.5 and 95.4% in groups 1 and 2, respectively. Mean duration of ulcer epithelization was 35.23 +/- 1.58 and 10.79 +/- 0.46 days, respectively. CONCLUSION: Clinically and pathogenetically sound method of H. pylori-associated GU with application of systemic and local (paraulcer) immunotropic ronkoleukine therapy is more cost and immunologically effective than standard treatment and can be used both in hospital and outpatient setting.

[Cardiac rhythm variability in patients with coronary heart disease and duodenal ulcer].

Nowadays most medical patients suffer from combined pathology. One of the most frequent examples is a combination of coronary heart disease (CHD) and duodenal ulcer (DL). The pathogenetic interrelations between these diseases have not been fully studied yet. Meanwhile, knowledge of shifts in cardiac rhythm variability (CRV) would widen the concept of the pathogenesis of these diseases, play predictory role, and allow individualization of prophylaxis and treatment. The subjects of this study were 23 patients suffering from CHD and DU. They were compared with 34 DU ulcer patients, and 15 CHD patients. The study revealed that in patients with combined pathology CRV was significantly lower than in those who had either CHD or DU.

[A case of secondary vasculopathy in gastric cancer]. / Sluchai vtorichnoi vaskulopatii pri rake zheludka.

A case is reported of a female patient who was admitted to hospital with diagnosis "hemorrhagic vasculitis". The examination detected gastric cancer. In the city cancer hospital the patient has undergone distal subtotal gastric and duodenal resection. In a few days after the operation skin eruption regressed and was not registered 4 months after surgery.