Genetic analysis of genotype G57 H9N2 avian influenza virus isolate A/chicken/Tajikistan/2379/2018 recovered in Central Asia

This paper presents genetic data on the full genome analysis of A/chicken/Tajikistan/2379/2018 H9N2 influenza virus isolated in September 2018 from chicken pathological material received from poultry farms of the Republic of Tajikistan and subtyped as H9N2 by serological and molecular methods. According to the results of hemagglutinin gene sequencing, the amino acid sequence of the cleavage site was RSSR/GLF, which is typical for low-virulent avian influenza virus. Phylogenetic analysis of the nucleotide sequence of a hemagglutinin gene fragment (nt 1-1539 of the open reading frame) showed that the A/chicken/Tajikistan/2379/2018 H9N2 isolate belongs to the Y280 genetic group of low-virulent A/H9 influenza virus, which is widespread in Southeast Asia. The complete nucleotide sequence of the viral genome was determined. Comparative analysis of all genomic segments revealed that the A/chicken/Tajikistan/2379/2018 H9N2 virus is closely related to an A/H9 influenza virus isolated in the Far East of the Russian Federation in 2018. Genetic similarity (97.1-99% identity in four out of eight viral genes) was found to isolates of an H7N9 subtype virus recovered in the Inner Mongolia and Hebei regions of China in 2017. According to the analysis of the predicted amino acid sequence of the studied isolate, the positions of some molecular markers indicate possible adaptation of the virus to mammals. Further genetic analysis showed that this virus belongs to genotype G57.

Extremophilic 50S Ribosomal RNA-Binding Protein L35Ae as a Basis for Engineering of an Alternative Protein Scaffold

Due to their remarkably high structural stability, proteins from extremophiles are particularly useful in numerous biological applications. Their utility as alternative protein scaffolds could be especially valuable in small antibody mimetic engineering. These artificial binding proteins occupy a specific niche between antibodies and low molecular weight substances, paving the way for development of innovative approaches in therapeutics, diagnostics, and reagent use. Here, the 50S ribosomal RNA-binding protein L35Ae from the extremophilic archaea Pyrococcus horikoshii has been probed for its potential to serve as a backbone in alternative scaffold engineering. The recombinant wild type L35Ae has a native-like secondary structure, extreme thermal stability (mid-transition temperature of 90°C) and a moderate resistance to the denaturation by guanidine hydrochloride (half-transition at 2.6 M). Chemical crosslinking and dynamic light scattering data revealed that the wild type L35Ae protein has a propensity for multimerization and aggregation correlating with its non-specific binding to a model cell surface of HEK293 cells, as evidenced by flow cytometry. To suppress these negative features, a 10-amino acid mutant (called L35Ae 10X) was designed, which lacks the interaction with HEK293 cells, is less susceptible to aggregation, and maintains native-like secondary structure and thermal stability. However, L35Ae 10X also shows lowered resistance to guanidine hydrochloride (half-transition at 2.0M) and is more prone to oligomerization. This investigation of an extremophile protein’s scaffolding potential demonstrates that lowered resistance to charged chemical denaturants and increased propensity to multimerization may limit the utility of extremophile proteins as alternative scaffolds.

[Peculiarities of the surgical treatment of nasal septum perforations]

The objective of the present study was the retrospective analysis of the results of nasal septum perforation (NSP) surgery. We report our experience with the operations on the perforated nasal septum based on the treatment of a total of 84 patients. Plastic repair of the perforated nasal septum was undertaken in 54 of them. The endonasal approach with the use of local tissue flaps was employed in 47 cases. Additional bucco-gingival flaps were used in another 4 patients and the open rhinoplastic approach in 3 cases. The complete closure of nasal septum perforations was achieved in 34 (63%) patients. The reduction of the size of perforations was documented in 17 (31%) patients whereas in the remaining three the perforation size slightly increased. The surgical technique and peculiarities of the postoperative management of the patients are described; the possible causes of NSP relapses following surgery are discussed.

[Influence of the structure of synthetic gestagens on their binding to progesteron receptors in the endometrium]

Chemical modification of progesterone molecule leads to changes both in the gestagenic activity of new derivatives and in their specific binding with progesterone receptors. The passage from esters (acetomepregenole, butagest) to the corresponding OH-forms such as 17a-acetoxy-3b-hydroxy-6-methyl-pregna-4,6-dien-20-one (ABMP)is accompanied by an increase in the binding with progesterone receptors in vitro. The translocation of a double bond from endocyclic (N6-N7) to exocyclic position (methylene group at N6 in ABMP) has no significant effect on the ability to binding with progesterone receptors.

Relative binding activity of new antigestagens with progesterone receptors in human hyperplastic endometrium

We determined the content and binding capacity of progesterone receptors in the endometrium of patients with adenomatous and fibroid polyps, adenocystic hyperplasia, and atypical hyperplasia before and after gestagen therapy. Hyperplasia of the endometrium was accompanied by changes in affinity of cytosolic progesterone receptors for antigestagens, which provides the possibility of individual correction of hormone therapy.