[Detection rates and high concentration of herpesvirus (Orthoherpesviridae) DNA in autopsy materials from patients with COVID-19 fatal outcome].

INTRODUCTION: SARS-CoV-2 infection causes immune disorders that create conditions for the reactivation of human herpesviruses (HHVs). However, the estimates of the HHVs effect on the course and outcome of COVID-19 are ambiguous. Аim - to study the possible relationship between the HHV reactivation and the adverse outcome of COVID-19. MATERIALS AND METHODS: Postmortem samples from the brain, liver, spleen, lymph nodes and lungs were obtained from 59 patients treated at the Moscow Infectious Diseases Hospital No.1 in 2021-2023. The group 1 comprised 39 patients with fatal COVID-19; group 2 (comparison group) included 20 patients not infected with SARS-CoV-2 who died from various somatic diseases. HHV DNA and SARS-CoV-2 RNA were determined by PCR. RESULTS: HHV DNA was found in autopsy samples from all patients. In group 1, EBV was most often detected in lymph nodes (94%), HHV-6 in liver (68%), CMV in lymph nodes (18%), HSV in brain (16%), VZV in lung and spleen (3% each). The detection rates of HHVs in both groups was similar. Important differences were found in viral load. In patients with COVID-19, the number of samples containing more than 1,000 copies of HHV DNA per 100,000 cells was 52.4%, in the comparison group - 16.6% (p < 0.002). An association has been established between the reactivation of HSV and HHV-6 and the severity of lung damage. Reactivation of EBV correlated with increased levels of liver enzymes. CONCLUSION: Reactivation of HHVs in patients with fatal COVID-19 was associated with severe lung and liver damages, which indicates a link between HHV reactivation and COVID-19 deaths.

[Development and properties of neutralizing monoclonal antibodies for fusion protein of respiratory syncytial virus.]

INTRODUCTION: Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections in infants and the elderly. The absence of a wide range of therapeutic drugs and vaccines indicates to the high relevance of the development of new effective drugs for the prevention and treatment of RSV infections. PURPOSE: to obtain highly active and specific monoclonal antibodies (MAbs) capable of detecting RSV in infected cells and neutralizing the infectious activity of the virus in vitro. MATERIAL AND METHODS: RSV reference strains of group A 2 subgroups (A2 and Long) were propagated in HEp-2 and MA-104 cell lines, respectively. Mice were immunized with purified RSV A2 virus. MAbs were obtained using hybridoma technology. RESULTS: A panel of 6 MAbs reacting with RSV strains А2 and Long has been obtained. Four MAbs were IgG (IgG2a or IgG2b subtype), two MAbs were IgM. All MAbs reacted with RSV F-protein in immunochemical tests. The MAbs actively reacted with RSV in ELISA, in immufluorescence and peroxidase staining of infected cells, and in immunodot test. Five out of 6 MAbs neutralized of RSV in cell culture. Different properties of MAbs suggest that they target different antigenic sites of F-protein. DISCUSSION: Comparative analysis suggests that the obtained MAbs can be used for the development of diagnostic preparations, for RSV detection in clinical materials and confirmation of infection etiology by rapid culture method. CONCLUSION: High activity and specificity of MAbs indicate that they can serve as a basis for development vaccines and preventive medicines.

Resistance of THP-1 Leukemia Cells Infected with Cytomegalovirus to Anti-tumor Antibiotic Doxorubicin and Restoration of the Sensitivity by Inhibitors of the PI3K/AKT/mTOR Molecular Pathway.

Results obtained showed that infection with HCMV prevented the death of THP-1 cells treated with DOX in both active and latent forms of infection. In the presence of mTOR inhibitors (rapamycin and Torin2), the sensitivity of the infected cells to DOX was restored. Rapamycin inhibited the expression of the HCMV protein IE1-p72 and increased sensitivity to DOX. Molecular targets for the creation of new drugs for the treatment of leukemia in patients infected with HCMV were determined.

[Biomonitoring in workers exposed to pesticides: development and application of method detecting imidacloprid in urine].

Imidacloprid is a relatively new insecticide in neonicotinoids chemical class with neuroactivity in insects, being one of the most widely used insecticides in the world. For biomonitoring in workers exposed to pesticides, the authors designed a method detecting low levels of Imidacloprid in urine of operators, based on tandem liquid mass-spectrometry with ionization source--electrostatic dispersion (positive ionization) in multi-reaction monitoring regime with subsidiary ion (mass/charge) 209 for quantitative assessment and ion 175.1 for confirmation onion ratio. The study incorporated diurnal urine, about 100 ml of average sample was frozen and kept at temperature -20C for analysis. Before extraction, the sample was unfrozen, an aliquot of 5 ml was selected, diluted with 5 ml of 0.1% formic acid. The substance was concentrated out of the urine samples via solid-phase extraction with application of cartridges based on octadecylsilane, eluition--1 ml of methanol. Lower limit of Imidacloprid detection in urine is 0.02 ng/ml, of the quantitative assessment--0.1 ng/ ml, linear range of concentrations measured 0.1-10 ng/ml. The method was tested for monitoring in workers exposed to Imidacloprid preparations in natural conditions of pesticides application in agriculture, with various processing technologies. Imidacloprid was identified in urine of two professional operators after work in seed treatment and the subsequent seeding at lower limit of detection (0.02 ng/ml) and 0.34 ng/ml.

[Determination of residual amounts of chlorothalonil in peaches: problems of gas chromatographic identification with the use of electron capture detector].

In the work there are presented results of studies on the validation of the gas chromatographic (GC) methodfor the determination of chlorothalonil residue amounts in peaches with the use of electron capture detector (ECD). For the analytical control there was selected such stone fruit crop as the peach, referring to the crops, the most contaminated with residue amounts ofpesticides. There was justified the necessity of the inclusion in the procedure of the detection of the method of confirmation, based on mass spectrometry detection (MSD) (the type of ionization - electron impact). The significant source of the obtaining of incorrect data in the identification with the use of ECD of ions are shown to be phthalates, visualized in the chromatogram as intense and/or broad peaks. Mass spectra of compounds of the class ofphthalates are characterized by the dominant peak of the ion with the value of (mass/ charge) 149, just on this peak the detection of low molecular weight phthalates occurs in various matrices, on the spectrum there are also recorded typical ions corresponding to fragments of radical residues. The combination of the use of various types of the detection allows to prove that the revealed response (detector signal) is caused just by the analyte, but not the impurities, and optionally to optimize chromatographic conditions towards to the obtaining reliable results. The lower limit of the quantitation of chlorothalonil in peach fruits accounts for 0.01 mg/kg, determined with a signal/noise ratio of 10. The range of measured concentrations is volatile between 0.01-0.1 mg/kg, recovery rate of chlorothalonil from samples of peaches, established according to results of the analysis of model samples with the introduction of the substance in four points along the detection range, was 84-102%, the SD value of the repeatability varies in the range of 2.0-5.8%.

[EFFECT OF ANTI-CANCER DRUG DOXORUBICINE ON CYTOMEGALOVIRUS INFECTED HUMAN FIBROBLASTS].

The anticancer antibiotic doxorubicine (DOX) is highly toxic and induces functional complications in vital organs. The effect of DOX on normal cells has not been examined in sufficient detail, and the search for compounds reducing DOX toxicity did not lead to success so far. It has been suggested that DOX induces death of cancer cells via p53-dependent apoptosis, however, the information regarding the role of p73 protein, a member of p53 tumor suppressor family, is scanty. Cytomegalovirus (CMV) induces an antiapoptosis program that allows its replication until death of the target cell. Our objectives were to examine the effect of DOX on normal cells (human fibroblasts), analyze the ability of CMV-induced antiapoptosis program to reduce DOX toxicity, and to evaluate the involvement of p73 protein and its isoforms in the regulation of death of CMV-infected and DOX-treated cells. Within a 24-h time period DOX caused death of about 70% human embryonic lung fibroblasts (HELF) in cell culture, this parameter decreased significantly in CMV-infected DOX-treated HELF cells. TUNEL has shown that the number of cells with DNA fragmentation decreases from 5.2% under the effect of DOX to 3.2% (P < 0.05) after combined CMV-DOX treatment. Analysis of mitotic figures revealed that DOX causes accumulation of mitotic cells, which was not observed in CMV-infected DOX-treated cells. PCR analysis of mRNA of two p73 protein isoforms (TAp73 and dNp73) has shown that in uninfected cells the expression of TAp73 isoform was low, while in CMV-infected cells level of TAp73 was significant and expression of dNp73 was demonstrated for the first time. Expression of TAp73 associated with lack of mitosis block. The activation of caspases 8, 9 and 3 in CMV-infected cells was registered but cell death was not, however, as massive as that caused by DOX. From these findings it can be concluded that CMV attenuates DOX-related damage to normal cells. It can be suggested that induction of TAp73 and dNp73 isoforms provides conditions for reduction of DOX effect which leads to DNA damage and death of normal cells.

[Different regulation of mitochondrial apoptosis and Bcl-2 gene expression in quescent and proliferative human fibroblasts infected with cytomegalovirus].

The aim of the study was to compare the dynamics ofmitochondrial apoptosis (MA) in cells at different stages of proliferation and with different susceptibility to cytomegalovirus (CMV). It has been found that in quiescent human fibroblasts (HF) CMV regulates MA at the level of bcl-2 gene transcription, exerting both pro- and anti-apoptotic effects. Suppression of bcl-2 transcription is greater in HF-977 line, which is highly susceptible to CMV in comparison with HF-1068 line. The effect of proliferative activity on MA was studied using CMV-infected HF-110044 line at the G0- or S-phase. A direct correlation was established between accumulation of cytochrome c and caspase 3 (MA markers) and production of IE72, pp65 and gB (CMV proteins). In G0-fibrob-lasts, viral replication was highly productive and bcl-2 expression was 10-fold as high as in S-phase cells, in which viral protein production and cell death were much lower. The increased gene transcription and accumulation of Bcl-2 protein enhanced cell viability and provided synthesis of viral proteins. Impaired structure of actin microfilaments, a caspase 3 target, coincided with pronounced suppression of gamma-actin gene in S-phase HF-110044. Our findings provide an insight into CMV-induced mechanisms of MA which lead to rapid death of infected quiescent fibroblasts and to slow death of cells infected at the stage of DNA synthesis.

[Monoclonal antibodies to highly pathogenic avian influenza A(H5N1) strain isolated in the Russian Federation: development and properties].

Highly pathogenic avian influenza (HPAI) virus subtype H5N1 has recently caused extensive epizootics in different regions of the world and presents a serious threat to man. Since 2005, HPAI virus subtype H5N1 strains have been circulating in Russia, which differ from the earlier isolated Southern Asia strains. A panel from 15 monoclonal antibodies (Mabs) to HPAI virus A/duck/Novosibirsk/56/05 (H5N1) was developed. Eleven Mabs interacted with the hemagglutinin molecule (HA), 4 with influenza A virus nucleoprotein (NP) in the Western blot assay. The bulk of the obtained Mabs interacted with homologous virus in ELISA and showed an antigen in the infected cells in the indirect immunofluorescence assay. Nine Mabs were active in the hemagglutination inhibition (HI) assay and 8 of them were capable to neutralize viral activity. The comparative analysis of the properties of Mabs in the HI assay using various influenza A strains showed that Mabs 2C6, 6F3, 4G10, 3G9, and 7B3 inhibited hemagglutination of study avian influenza viruses subtype H5, Mab 6F3 being most active. Mab 3B5 reacted only with the viruses isolated in the Russian Federation in 2005-2007 and failed to interact with the other study influenza A viruses subtype H5. The obtained panel of Mabs can be used to study the fine antigenic structure of hemagglutinin and to make a differential diagnosis of avian influenza viruses subtype A/H5N1. The high neutralizing activity of Mabs creates a prospect for preparing humanized antibodies for specific prevention and treatment.

[CMV-induced cell death and fas gene expression in resting and proliferating human fibroblasts].

Cytomegalovirus (CMV) infection development and mRNA fas transcription levels (CD95) in resting (GO) and proliferating (S-phase) human lung embryo fibroblasts (HLEF-110044 line) were studied. In GO cells accumulation of infectious CMV was high and cell death was very quick, and fas gene expression was inhibited in early period of infection. In cells infected during S-phase CMV synthesis was lower and total cell death was detected only after 5 days; fas gene activity remained on high levels and increased during 6-48 hours. Death of CMV-infected fibroblasts occurred through apoptosis with cytopathic effect and detachment of cells in early stage, but without changes of cell membrane permeability and internucleosome fragmentation of DNA during later stages. In another HLEF-977 line CMV-induced apoptosis correlated with increased levels of fas gene transcription in resting cells. Positive association of activation Fas-receptor pathway and cell proliferation as well as different effect of CMV on activity of fas gene in 2 HLEF lines are discussed.

[Methodological aspects of gas-mercury monitoring of non-industrial areas]. / Metodicheskie aspekty gazortutnogo monitoringa neproizvodstvennykh ob"ektov.

The paper presents new methodological approaches to gaseous mercury monitoring whose key link is to record the territorial background level of air pollution, which is calculated by using the frequency distribution diagrams of single measurements for uniform objects within an area by comparing them with logarithmically normal random distribution. The methodological approach has been used during surveys of schools and preschool children establishments in Moscow, Kaluga, and the Kaluga Region.

[Suppression of cytomegalovirus infection in cell system by fullerene amino acid derivates]. / Podavlenie tsitomegalovirusnoi infektsii v kletochnoi sisteme aminokislotnymi proizvodnymi fullerena.

Effects of two water-soluble derivatives of fullerene C60-o-aminocaproic acid (C60-ACA) and C60 sodium salt of omega-aminocaproic acid (C60-Na-ACA) on in vitro cytomegalovirus (CMV) infection were studied. C60-Na-ACA 4-5-fold inhibited the cytopathic effect of CMV in comparison with C60-ACA, the effective dose for C60-Na-ACA being 0.6 microgram/ml and that for C60-ACA 2.7 micrograms/ml. Immunocytochemical analysis of virus proteins in infected cells has shown that C60-Na-ACA inhibits the production of late structural CMV protein gB, but does not modify the expression of immediate early nonstructural protein IEp72. Studies of cell viability, growth characteristics, and DNA synthesis revealed that the cytotoxic effect of C60-Na-ACA on human diploid fibroblasts in negligible, the cytotoxicity index varying from 160 to 1500 micrograms/ml in different tests. Selectivity index for C60-Na-ACA is 267-2500, which differs negligibly from that of gancyclovir (100-1000), while the cytotoxicity of C60-Na-ACA is essentially lower.

[Effect of cytomegalovirus on cell cycle progression and formation of pathological mitoses in cultured human diploid fibroblasts]. / Vliianie tsitomegalovirusa na prokhozhdenie kletochnogo tsikla i formorovanie patologicheskikh mitozov v kul'ture diploidnykh fibroblastov cheloveka.

The effect of cytomegalovirus on the cell cycle was studied autoradiographically in an asynchronous culture of human diploid fibroblasts. The analysis of labeled mitosis showed that some cells infected in the S phase ceased to progress through the cell cycle at one of its phases (S, G2, or M); at the same time, at least part of infected cells remained capable of entering mitosis. Beginning from day 2 after infection by cytomegalovirus, the accumulation of pathological mitotic cells blocked at metaphase was observed in the culture. Approximately 50% of these cells contained 3H-thymidine label above chromosomes. This fact suggested the possibility of pathological mitosis in cells that were infected both at the S and other phases of the cell cycle. The detailed morphological analysis of chromosomes at different stages of infection demonstrated that the degree of their morphological changes increases from slight (stronger condensation) to severe pathology (fragmentation). In the aggregate, the results of the study suggested that abnormal chromosome morphology resulted from irreversible cell division arrest under the effect of cytomegalovirus.