Structure and dynamics of the interaction of Delta and Omicron BA.1 SARS-CoV-2 variants with REGN10987 Fab reveal mechanism of antibody action.

Study of mechanisms by which antibodies recognize different viral strains is necessary for the development of new drugs and vaccines to treat COVID-19 and other infections. Here, we report 2.5 Å cryo-EM structure of the SARS-CoV-2 Delta trimeric S-protein in complex with Fab of the recombinant analog of REGN10987 neutralizing antibody.

Properties and Activity of Peptide Derivatives of ACE2 Cellular Receptor and Their Interaction with SARS-CoV-2 S Protein Receptor-Binding Domain.

The aim of this work was to design and characterize peptides based on the α-helices h1 and h2 of the ACE2 receptor, forming the interaction interface between the receptor-binding domain (RBD) of the SARS-CoV-2 S protein and the cellular ACE2 receptor. Monomeric and heterodimeric peptides connected by disulfide bonds at different positions were synthesized. Solubility, RBD-binding affinity, and peptide helicity were experimentally measured, and molecular dynamics simulation was performed in various solvents.

Nucleoside Analogs and Perylene Derivatives Modulate Phase Separation of SARS-CoV-2 N Protein and Genomic RNA In Vitro.

The life cycle of severe acute respiratory syndrome coronavirus 2 includes several steps that are supposedly mediated by liquid-liquid phase separation (LLPS) of the viral nucleocapsid protein (N) and genomic RNA. To facilitate the rational design of LLPS-targeting therapeutics, we modeled N-RNA biomolecular condensates in vitro and analyzed their sensitivity to several small-molecule antivirals. The model condensates were obtained and visualized under physiological conditions using an optimized RNA sequence enriched with N-binding motifs.

Microarray Profiling of Vaccination-Induced Antibody Responses to SARS-CoV-2 Variants of Interest and Concern.

Mutations in surface proteins enable emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to escape a substantial fraction of neutralizing antibodies and may thus weaken vaccine-driven immunity. To compare available vaccines and justify revaccination, rapid evaluation of antibody (Ab) responses to currently circulating SARS-CoV-2 variants of interest (VOI) and concern (VOC) is needed. Here, we developed a multiplex protein microarray-based system for rapid profiling of anti-SARS-CoV-2 Ab levels in human sera.

Autoimmune Effect of Antibodies against the SARS-CoV-2 Nucleoprotein.

COVID-19 caused by SARS-CoV-2 is continuing to spread around the world and drastically affect our daily life. New strains appear, and the severity of the course of the disease itself seems to be decreasing, but even people who have been ill on an outpatient basis suffer post-COVID consequences. Partly, it is associated with the autoimmune reactions, so debates about the development of new vaccines and the need for vaccination/revaccination continue.

COVID-19 pandemic in Saint Petersburg, Russia: Combining population-based serological study and surveillance data.

Background: The COVID-19 pandemic in Russia has already resulted in 500,000 excess deaths, with more than 5.6 million cases registered officially by July 2021. Surveillance based on case reporting has become the core pandemic monitoring method in the country and globally.

Seroprevalence of SARS-CoV-2 antibodies in Saint Petersburg, Russia: a population-based study.

Properly conducted serological survey can help determine infection disease true spread. This study aims to estimate the seroprevalence of SARS-CoV-2 antibodies in Saint Petersburg, Russia accounting for non-response bias. A sample of adults was recruited with random digit dialling, interviewed and invited for anti-SARS-CoV-2 antibodies.

Evaluation of the performance of SARS--CoV--2 antibody assays for a longitudinal population-based study of COVID--19 spread in St. Petersburg, Russia.

Geographical variation in severe acute respiratory syndrome coronavirus 2 (SARS--CoV--2) spread requires seroprevalence studies based on local tests, but robust validation is needed. We summarize an evaluation of antibody tests used in a serological study of SARS--CoV--2 in Saint Petersburg, Russia. We validated three different antibody assays: chemiluminescent microparticle immunoassay (CMIA) Abbott Architect SARS--CoV--2 immunoglobulin G (IgG), enzyme- linked immunosorbent assay (ELISA) CoronaPass total antibodies test, and ELISA SARS--CoV--2--IgG--EIA--BEST.

Correction to: Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches.

An amendment to this paper has been published and can be accessed via the original article.

Generation of recombinant VP3 protein of infectious bursal disease virus in three different expression systems, antigenic analysis of the obtained polypeptides and development of an ELISA test.

Infectious bursal disease virus (IBDV), which infects young chickens, is one of the most important pathogens that harm the poultry industry. Evaluation of the immune status of birds before and after vaccination is of great importance for controlling the disease caused by this virus. Therefore, the development of low-cost and easy-to-manufacture test systems for IBDV antibody detection remains an urgent issue.

Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches.

Background: Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today.

Results: We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana.

Complete Genome Sequence of a Novel Very Virulent Strain of Infectious Bursal Disease Virus Circulating in Russia.

A novel strain of infectious bursal disease virus, named DD1, was isolated from broiler chickens in Russia in 2016. Here, we present its complete genome sequence. Nucleotide sequence analysis of both segments of the virus suggests that it belongs to a group of very virulent strains.

Interrogation of metabolic and oxygen states of tumors with fiber-based luminescence lifetime spectroscopy.

The study of metabolic and oxygen states of cells in a tumor in vivo is crucial for understanding of the mechanisms responsible for tumor development and provides background for the relevant tumor's treatment. Here, we show that a specially designed implantable fiber-optic probe provides a promising tool for optical interrogation of metabolic and oxygen states of a tumor in vivo. In our experiments, the excitation light from a ps diode laser source is delivered to the sample through an exchangeable tip via a multimode fiber, and the emission light is transferred to the detector by another multimode fiber.

Draft mitochondrial genomes of and (Annelida, Hirudinea).

Here we present two incomplete mitochondrial genome sequences of and (Annelida, Hirudinea). The corresponding sequences are 14,729 and 14,604 base pairs in length. They contain all mitochondrial genes (13 protein-coding genes, 22 tRNAs and two rRNAs) but lack the non-coding region.

[PAIN AFTER CHILDBIRTH AND ITS IMPACT ON QUALITY OF LIFE].

Background: Public attitude towards labor pain and pain relief in labor is not fully formed.

Purpose: To study the frequency of formation of acute and chronic pain during delivery.

Materials And Methods: Retrospectively we surveyed 300 women 18-48 years old, who had childbirth naturally or by caesarean section for 4-6 months before the survey and analyzed the history of their childbirth.

Complete Genome Sequence of an Enterotoxigenic Bacteroides fragilis Clinical Isolate.

Here we present the complete genome sequence of Bacteroides fragilis isolate BOB25. It is an enterotoxigenic isolate that was obtained from a stool sample of a patient with dysbiosis.

Preparation and functional evaluation of RGD-modified streptavidin targeting to integrin-expressing melanoma cells.

The vertical growth stage is the most dangerous stage of melanoma and is often associated with a poor prognosis. The increased invasiveness and metastasis that is typical for vertically growing melanoma are mediated by the molecules of cell adhesion (particularly, integrins). Integrin αvβ3, which is abundantly expressed on melanoma cells with high metastatic potentials and is characterized by low expression levels in normal melanocytes, is potentially an attractive target for melanoma diagnostics and therapy.

[Designing of hybrid human interferon alfa-2 strain-producers and the use of enteropeptidase for obtaining N-terminal methionine-free interferons].

A system for production of human interferon-alpha2a (IFN-alpha2a) and IFN-alpha2b lacking N-terminal methionine has been developed. Plasmids containing genes of hybrid IFN-alpha2 under the control of different promoters were constructed; a sequence encoding the enteropeptidase hydrolysis site being introduced in proximal part of the genes. As the result, 4 strains of Escherichia coli producing hybrid IFN-alpha2 have been obtained.

[Complications of endoscopic video-assisted surgical interventions in gynaecology].

An analysis of specific complications in gynaecological endovideosurgery has been conducted, such as occurrence of extra-abdominal gas after laparoscopic surgery or resorption of the irrigation solution in hysteroscopy. Possible mechanisms of subcutaneous emphysema, pneumothorax, mediastinal emphysema and hyperhydration development are presented along with discussion of diagnosing and treatment methods.

[Patient-controlled postoperative analgesia in obstetrics and gynaecology].

A prospective study researches features of patient-controlled epidural analgesia (PCEA) in 42 women after cesarean section, mid- and high-traumatic gynaecological surgery. It was found out that the quality of while using the PCEA is significantly better than while using a traditional parenteral infusion of analgesics. Use of PCEA favours the circulatory and breathing systems functioning.

A case of HHV-8-associated HIV-negative primary effusion lymphoma in Moscow.

Primary effusion lymphoma is a rare tumor of B-cell derivation which is associated with human herpes virus type 8 (HHV-8) in 100% and with human immunodeficiency virus (HIV) in most of cases. The paper describes the first case in Russia of HIV(-) HHV-8(+) Epstein-Barr virus (EBV)(+) primary effusion lymphoma in a male patient aged 56 years. The tumor was located in the pleural cavity.

[Characteristics of hemodynamic reactions during various endoscopic surgeries for cholelithiasis in patients with concurrent cardiovascular pathologies].

A prospective study of 170 patients with concurrent cardiac pathology, who had underwent the laparoscopic cholecystectomy under the conditions of a tense carboxyperitomium, led to isolating two groups of patients with high-risk of intra- and postoperative unfavorable cardiac-vascular responses: an original high risk degree (III-IV classes according to ASA), a high value of cardiac risk indices according to Goldman (III-IV classes) and according to Detsky (II-III classes), a hypodynamic blood circulation regimen under rest conditions, and ejection fraction (according to echocardiography) amounting below 50%. Such patients are recommended to be operated on by laparolifting or by low-gas laparoscopy with a local lifting, i.e.

[Effect of premedication on the formation of postoperative pain syndrome].

The pronouncement degree and dynamics of pain syndrome were assessed after surgeries in the abdominal cavity organs with regard for a nature of the analgetic component of premedication and of the postoperative analgesic therapy (n = 155). The administration of analgesics before extra-traumatic surgeries was found to be compulsory in order to prevent the onset of a persistent postoperative pain syndrome. A combination of non-steroid anti-inflammatory drugs, i.

[Mathematical modeling -- an objective assessment of new medicines and treatment technologies].

An objective method of studying effectiveness of new medicines and methods of treatment is mathematical modeling. On the basis of mathematical processing of the pooled data obtained in the control group of patients an individual prognostic formula can be made which predicts the only outcome for each patient. When studying a new medicine or method of treatment in each patient under test his prognostic outcome is compared to the real one.

[Diagnosis and intensive therapy of thermal and inhalation trauma].

The authors made an analysis of an experience with treatment of patients with a combined thermal inhalation injury in the Burn Center of the St. Petersburg Research Institute of emergency medical care named after I.I.