The investigation of the dynamics of changes in neutralizing antibody titers against type 5 adenovirus in the context of vaccination against a new coronavirus infection

This research focuses on analyzing the dynamics of neutralizing antibody (nAbs) titers against type 5 adenovirus (Ad5) in the adult population of Russia following vaccination against the novel coronavirus infection with recombinant adenovirus type-5 COVID-19 vaccine (CanSino Biologics, China). The impact of the Ad5 vector on nAb titers was investigated using 302 blood serum samples from individuals who received a single dose of the Ad5-nCoV vector vaccine. The research revealed that 33.8% of adults in Russia had pre-existing anti-Ad5 nAbs before the pandemic. Notably, 40% of vaccinated individuals did not exhibit an increase in nAbs titers upon receiving the Ad5-based vaccine. However, in the group with no or low titers of anti-Ad5 nAbs (1:10-1:40), a significant 8-16-fold increase in nAb titers to Ad5 was observed.

Polyfluoroalkylated antipyrines in Pd-catalyzed transformations

In the direct C–H arylation with arylhalogenides in the presence of Pd(OAc)₂, trifluoromethyl-containing antipyrine reacts very slowly and incompletely owing to the low nucleophilicity of its C4 center. However, it was effective in modifying polyfluoroalkyl-substituted 4-bromo- and 4-iodo antipyrines by the Suzuki and Sonogashira reactions. It was established that using Pd₂(dba)₃ as catalyst and XPhos as phosphine ligand was the optimal catalytic system for the synthesis of 4-aryl- and 4-phenylethynyl-3-polyfluoroalkyl-antipyrines. Moreover, iodo-derivatives as the initial reagents were found to be more advantageous compared to bromo-containing analogs. It was found that 4-phenylethynyl-5-CF₃-antipyrine has a moderate activity against the influenza virus A/Puerto Rico/8/34 (H1N1) and 4-iodo-5-CF₃-antipyrine reveals a weak activity against the vaccine virus (strain Copenhagen) and bovine diarrhea virus (strain VC-1).

Peculiarities of heterocyclic systems with electron-withdrawing groups (polyfluoroalkyl-containing antipyrines) in Pd-catalyzed C–H arylation and cross-coupling reactions.

Antiviral activity of amides and carboxamides of quinolizidine alkaloid (-)-cytisine against human influenza virus A (H1N1) and parainfluenza virus type 3

Novel derivatives of quinolizidine alkaloid (-)-cytisine were synthesised. ADME properties, cytotoxicity against HEK293 cells and activity against viruses of influenza A/California/07/09(H1N1)pdm09 virus (IAV) and human parainfluenza virus type 3 (HPIV3) were evaluated. It was shown, that 9-carboxamides of methylcytisine (with phenyl and allyl urea's fragments) are most active compounds against IAV probably due to predicted in silico peculiarity of their interactions with the 4R7B active site of IAV neuraminidase. Indexes of selectivity (SI) calculated as ratio of CC₅₀/IC₅₀ of these ureas are 47 and 59 correspondingly. It was also found, that derivatives obtained from allyl isocyanate and (-)-cytisine or 9,11-dibromocytisine are able to inhibit a reproduction of HPIV3 with SI = 58 and 95. Moreover, last compound - (1 R,5R)-N-allyl-9,11-dibromo-8-oxo-1,5,6,8-tetrahydro-2H-1,5-methanopyrido[1,2-a][1,5]diazocine-3(4H)-carboxamide with two bromine atom in 2-pyridone core of starting (-)-cytisine molecule, demonstrated high activity against HPIV3 (SI = 95) and moderate activity against IAV (SI = 16).

Synthesis of camphecene derivatives using click chemistry methodology and study of their antiviral activity

A series of seventeen tetrazole derivatives of 1,7,7-trimethyl-[2.2.1]bicycloheptane were synthesized using click chemistry methodology and characterized by spectral data. Studies of cytotoxicity and in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells of the compounds obtained were performed. The structure-activity relationship analysis suggests that to possess virus-inhibiting activity, the compounds of this group should bear oxygen atom with a short linker (C2-C4), either as a hydroxyl group (18, 19, 29), keto-group (21) or as a part of a heterocycle (24). These compounds demonstrated low cytotoxicity along with high anti-viral activity.

[Comparative study of MDCK and CaCo-2 cell lines for influenza virus isolation]

Study of effectiveness of CaCo-2 cell line for influenza virus isolation was carried out. It was shown that the properties of this cell line strongly depended on the source of its origin and cultivation conditions. The infectious activity of the influenza viruses on CaCo-2 cell line was virtually the same as in the MDCK cell line. The rate of the viral isolation was virtually identical for both cell lines tested, but viruses from post-mortem materials were isolated only in CaCo-2 cell line. In general, the CaCo-2 line is believed to be a valuable cell line for virological research, particularly for influenza virus isolation.

[Analysis of tuberculosis quality diagnosis by autopsy data]

The records of autopsies and history cases of deceased patients served as a material for analyzing the quality of clinical diagnosis of tuberculosis in 1987-1997. A hundred and eighty and six patients (39.1%) were autopsied. Of them 139 (74.7%) and 47 (25.3%) died from tuberculosis and other diseases, respectively. Tuberculosis and its complications were recognized in 113 (81.3%) patients during their life. Fibrocavernous tuberculosis was a prevalent clinical form in 104 (55.9%) of the deceased. Progressive tuberculosis, more commonly as complications of cavernous tuberculosis (in 49 (35.2%) patients) and those of hematogenic generalization (in 23 (16.5%)) were a direct cause of death in most tuberculosis patients (n = 72 (51.8%)).