Changes in the peripheral blood cellular composition were observed in the long term period in the residents of the Techa riverside villages chronically exposed to radiation, which may be the consequence of structural and functional disorders in the pool of hematopoietic stem cells (HSC) and progenitor cells. Therefore, the study was aimed to quantify peripheral blood CD34+ cell pool in individuals chronically exposed to radiation over a long-term period. Sixty years after the onset of exposure, a total of 153 individuals were examined, who were divided into four groups: individuals exposed in utero and postnatally (the average postnatal absorbed dose was 570 mGy); individuals exposed only postnatally (the average postnatal absorbed dose was 790 mGy), and two comparison groups, in which the average postnatal absorbed dose to red bone marrow did not exceed 70 mGy. Absolute and relative peripheral blood CD34+ cell counts in chronically exposed individuals were assessed by flow cytometry. No changes in CD34+ cell counts compared to comparison group were revealed in the group of individuals exposed in utero and postnatally; no age-related changes were registered as well. However, a significant decline in absolute HSC and progenitor cell counts with increased absorbed dose to red bone marrow was observed. In the group of individuals exposed only postnatally, there was a significant increase in peripheral blood CD34+ cell counts compared to comparison group (p = 0.004 for absolute cell count; p = 0.009 for relative cell count), dose-dependent increase in peripheral blood HSC and precursor cell counts (p = 0.02 for absolute cell count; p = 0.03 for relative cell count), along with age-related decline in these cells’ counts (р = 0.02 for absolute cell count; p = 0.04 for relative cell count).
DNA methylation is the most common epigenetic modification, caused by ionizing radiation. There may be both hypermethylation, which suppresses transcription of gene promoter regions, and hypomethylation, resulting in gene activation. Both mechanisms may be involved in carcinogenesis. The study was aimed to assess methylation status of CpG islands in the protective system BCL-2, CDKN1A and ATM gene promoters in the peripheral blood cells of the chronically exposed individuals, living in the villages, located along the Techa River, over a long-term period. Methylation of BCL-2, CDKN1A and ATM gene promoter regions in 68 residents of the villages, located along the Techa River (Chelyabinsk region), was assessed by the real-time methylation-specific PCR. The group of exposed individuals included 54 people with accumulated dose to red bone marrow within the range of 0.09–3.51 Gy. The comparison group included 14 people, living in similar economic and social environment, with the dose to red bone marrow, accumulated during the whole life, not exceeding 70 mGy. The pilot study of exposed individuals over a long period of time after chronic low-dose radiation exposure revealed no significant changes in methylation levels of CpG islands in the CDKN1A, BCL-2, ATM gene promoter regions compared to the comparison group. None were revealed in the dose subgroups “87–994 mGy” and “over 1000 mGy”.
Pseudomonas aeruginosa — is one of the pathogens characterized by the critical number of multidrug-resistant (MDR) strains. Phage therapy is considered an alternative to antibiotics, especially in treatment of infections caused by MDR strains. The aim of this study was to isolate and characterize P. aeruginosa phages that could potentially be suitable for treating infectious diseases. To isolate the P. aeruginosa phages, enrichment cultures were used. The lytic activity spectrum was confirmed by spot testing on 40 P. aeruginosa strains. Whole-genome sequencing was performed using Illumina MiSeq instrument. Phylogenetic analysis was done using VICTOR tool. Isolated phages vB_PaeA-55-1w and vB_PaeM-198 from Autographiviridae and Myoviridae families, respectively, had a broad spectrum of lytic activity (about 50% each), including lysis of MDR strains. The genomes vB_PaeA-55-1w and vB_PaeM-198 comprise double-stranded DNA of 42.5 and 66.3 kbp in length, respectively. Open reading frames were annotated for both phages (52 for vB_PaeA-55-1w, and 95 for vB_PaeM-198), no integrases and toxins were detected. On a phylogenetic tree, vB_PaeA-55-1w phage was clustered with phages from the Phikmvvirus genus (Autographiviridae family), which are also used in phage therapy. vB_PaeM-198 phage was clustered with phages from the Pbunavirus genus (Myoviridae family). vB_PaeA-55-1w and vB_PaeM-198 phages could be considered as candidates for phage therapy and may be used to treat infections caused by MDR P. aeruginosa.
The efficacy of mefloquine has not been studied in the in vivo experiments and clinical trials involving COVID-19 patients. The study was aimed to assess the effects of mefloquine on the SARS-CoV-2 accumulation in the lungs of infected animals and to study the efficacy and safety of mefloquine compared to hydroxychloroquine in patients with COVID-19. During the experiment, a total of 96 Syrian hamsters were infected with SARS-CoV-2. Accumulation of the virus in lungs was compared in the groups of animals treated with mefloquine and ribavirin and in the control group. During the clinical trial, the mefloquine and hydroxychloroquine safety and efficacy in patients with mild and moderate COVID-19 (172 individuals) was assessed based on the symptom changes over time and the computed tomography results. The experiment showed that the SARS-CoV-2 accumulation in the lungs of Syrian hamsters 6 days after infection and mefloquine treatment was 2.2 ± 0.18 lg PFU/g, which was lower (p < 0.05) than in the control group (3.5 ± 0.21 lg PFU/g) and ribavirin group (5.2 ± 0.05 lg PFU/g). During the clinical trial, it was found that 50.0% of patients in the mefloquine group and 32.4% in the hydroxychloroquine group (р < 0.05) developed a mild disease, and the completely resolved respiratory failure was registered in 76.5% and 44.6%, respectively (р < 0.001). Adverse events were observed in 86.7 % and 77% of patients in the mefloquine and hydroxychloroquine groups, respectively (р > 0.05). Thus, during the experiment, mefloquine contributed to the faster virus titer reduction in the lungs. During the clinical trial, the mefloquine efficacy was non-inferiority or, based on a number of indicators, higher compared to hydroxychloroquine, with comparable safety.
Phage therapy is a promising method of treating antibiotic-resistant infections. To obtain a safe therapeutic formulation, bacterial cell components, including endotoxins, must be removed from the phage lysate. This study was aimed at comparing the efficacy of purification methods for phage lysates intended for therapeutic use. Phages vB_KpnM_Seu621 (Myoviridae) and vB_KpnP_Dlv622 (Autographiviridae) were grown using the KP9068 strain of Klebsiella pneumoniae as a host. The obtained lysates were purified using phage precipitation with polyethylene glycol, CsCl density gradient ultracentrifugation, sucrose density gradient ultracentrifugation, precipitation with 100 kDa centrifugal filter units, and phage concentration on 0.22 μm cellulose filters in the presence of MgSO4. Endotoxin concentrations were determined by LAL testing. The obtained lysates contained 1.25 × 1012 ± 7.46 × 1010 and 2.25 × 1012 ± 1.34 × 1011 PFU/ml of vB_KpnM_Seu621 and vB_KpnP_Dlv622, respectively, and had endotoxin concentrations of 3,806,056 ± 429,410 and 189,456 ± 12,406 EU/ml, respectively. CsCl gradient ultracentrifugation was found to be the optimal conventional purification method in terms of reducing endotoxin concentrations and maintaining phage titers (303 ± 20 — 313 ± 35 EU/ml, 1.5–2.75 × 1012 ± 1.71 × 1011 PFU/ml). Sucrose gradient ultracentrifugation and filtration in the presence of MgSO4 were found to be the optimal non-traditional purification methods. A method for phage lysate purification should be selected for each phage preparation individually. Sucrose gradient ultracentrifugation and filtration in the presence of MgSO4 hold promise as purification methods that can produce phage preparations suitable for intravenous administration.
Plasma membrane is one of the major targets for cationic antiseptics (CA). The study was aimed to assess molecular effects of CAs of different chemical classes on cardiolipin-containing regions of bacterial plasma membranes. The study was carried out using coarse-grained molecular modeling. Interaction of CAs, such as miramistin, chlorhexidine, picloxidine, and octenidine, with cardiolipin-containing bilayer was assessed based on the CA coarse-grained models. CAs reduced lipid lateral diffusion coefficients and increased the membrane area per lipid. All CAs, except miramistin, reduced the lipid fatty acid chain order parameters. Adding octenidine at a CA : lipid ratio of 1 : 4 resulted in cardiolipin clustering with subsequent pulling the neutral phosphatidylethanolamine molecules out of the model bilayer. It was found that CАs have the potential for sorption to lipid bilayer, causing clustering of negatively charged lipids. Antiseptic octenidine causes formation of cardiolipin microdomains. Abnormal lateral lipid distribution together with pulling out phosphatidylethanolamine molecules can result in increased lipid bilayer permeability. The most significant reduction of cardiolipin lateral diffusion coefficient by 2.8 ± 0.4 times was observed in the presence of CA chlorhexidine at an antiseptic : lipid ratio of 1 : 4.
Effective therapy of amiodarone-induced hepatotoxicity requires studying the mechanisms of the toxic effects of amiodarone on hepatocytes and assessing the potential impact of hepotoprotective agents. The study was aimed to assess hepatoprotective effects of antioxidants on the amiodarone-induced hepatotoxicity with the use of immortalized human hepatoma cells of the HepaRG cell line. Cell viability was evaluated upon exposure to amiodarone and in the mixture with vitamin Е, N-acetylcysteine and S-adenosylmethionine by impedance measurement; the levels of some hepatotoxicity biomarkers were defined using the Luminex xMAP technology. As a result of the research, the dose-dependent toxic effects of amiodarone were established. The IC50 value of amiodarone in the HepaRG cell line was 3.5 μМ. It is shown that cytotoxic effects decrease and the IC50 value increases in the presence of vitamin Е, N-acetylcysteine and S-adenosylmethionine. Amiodarone reduces the activity of cell cycle regulators: AKT, JNK kinases, and p53 protein. Exposure to amiodarone results in reduced intracellular ATP levels and the release of intracellular enzymes (malate dehydrogenase 1, glutathione S-transferase, sorbitol dehydrogenase, 5'-nucleotidase) into conditioned medium, indicating the necrotic cell death. Thus, vitamin Е, S-adenosylmethionine and N-acetylcysteine reduce amiodarone cytotoxicity in the model of amiodarone-induced damage to hepatocytes and can be considered as hepatoprotective agents in case of the need to protect liver against the hepatotoxic effects of amiodarone.
Respiratory muscles (RM) are a very important part of the respiratory system that enables pulmonary ventilation. This study aimed to assess the post-COVID-19 strength of RM by estimating maximum static inspiratory (MIP or PImax) and expiratory (MEP or PEmax) pressures and to identify the relationship between MIP and MEP and the parameters of lung function. We analyzed the data of 36 patients (72% male; median age 47 years) who underwent spirometry, and body plethysmography, diffusion test for carbon monoxide (DLCO) and measurement of MIP and MEF. The median time between the examinations and onset of COVID-19 was 142 days. The patients were divided into two subgroups. In subgroup 1, as registered with computed tomography, the median of the maximum lung tissue damage volume in the acute period was 27%, in subgroup 2 it reached 76%. The most common functional impairment was decreased DLCO, detected in 20 (55%) patients. Decreased MIP and MEP were observed in 5 and 11 patients, respectively. The subgroups did not differ significantly in MIP and MEP values, but decreased MIP was registered in the second subgroup more often (18%). There were identified no significant dependencies between MIP/MEP and the parameters of ventilation and pulmonary gas exchange. Thus, in patients after COVID-19, MIP and MEP were reduced in 14 and 31% of cases, respectively. It is reasonable to add RM tests to the COVID-19 patient examination plan in order to check them for dysfunction and carry out medical rehabilitation.
The Regional center of conditioning and long-term storage of radioactive waste is being constructed in Primorsky Krai, where radioactive waste (RW) management сoncerns have been especially acute. The project involves intensification of activities related to RW management, as well as to building the new technology block for RW reprocessing, storage facility and boiler house. The study was aimed to perform environmental impact assessment of the territories in the vicinity of the Regional center of conditioning and long-term storage of radioactive waste prior to the facility commissioning. Radiation situation was assessed by radiometric and spectrometric methods; the levels of heavy metals were evaluated by atomic absorption spectrometry. Heavy metal (lead, nickel, copper, etc.) and arsenic levels exceeding or, in certain cases, similar to maximum permissible concentration (MPC) were found in soil and ground. Radiation situation is characterized by background levels of artificial radionuclides 137Cs and 90Sr in environmental media. Quality of water in wells and boreholes was largely compliant with the requirements established for groundwater used in decentralized water supply systems, with the exception of boreholes, in which the arsenic levels exceeding MPC were detected. The average annual public dose was 0.046 mSv excluding natural regional background radiation, which was below the dose limit. Carcinogenic health risks induced by radiation and chemical factors was 4×10–6 and 6×10–6 respectively. The obtained results form the basis for setting reference values of environmental contamination prior to the Regional center of conditioning and long-term storage of radioactive waste commissioning and can be used for regulatory supervision during the facility operation.
Identification of novel low molecular weight compounds with antitumor activity is the first important step towards the development of candidate drugs and a popular trend in in vitro pharmacology. The aim of the study was to assess the key trends and rank the scientific priorities in anticancer drug design using bibliometric analysis. The protocol involved using the panel of bibliographic databases (PubMed, Scopus, Cortellis) and analytical web-based tools PubChem, FACTA +, ClustVis, Reaxys, PathwayStudio and VOSviewer software to review a sample of 1657 papers issued 2020–2021.The work was also focused on 70 new promising basic structures and derivatives targeted at inhibiting both individual pro-tumor proteins and signaling cascades. It was found that serine-threonine protein kinases, receptor tyrosine kinases, DNA topoisomerases and tubulins as well as signaling pathways PI3K, mTOR, AKT1, STAT3, HIF-1a, and p53 account for up to 60% of the total structure of cellular targets for the design of anticancer drugs. The increasing scientific interest in innovative inhibitors of tumor-associated protein complexes, transcription factors and metabolic enzymes has been found. The compounds, which belong to heterocycles, glycosides, quinones and terpenes, were mentioned in 71% of papers as the basic structures for antitumor derivatives design. Papers, published in 2019, in which the compounds, such as lapachone, luteolin, quercetin, monastrol, and crisosplenol D are studied in the context of the design of new drug prototypes, have the highest citation rate. The systematic bibliometric approach involving the use of a panel of analytical resources makes it possible to assess R&D trends and scientific priorities in anticancer drug design, thus organically complementing the classic reviews in periodicals.
Inactivation of influenza virus and other potential contaminants like avian adenoviruses coming from embryonated chicken eggs is a critical step in the production of inactivated influenza vaccines. Inactivation must lead to a guaranteed reduction in contaminant titers by at least 4 lg (PFU)/ml. The aim of this study was to identify an optimum cell line for adenovirus propagation and to estimate a reduction in adenovirus titers in vaccine intermediates after inactivation. In a series of experiments, we identified the optimum conditions and the optimum cell line for the propagation of avian adenovirus (strains CELO and Fontes). The most commonly used inactivation methods were analyzed, including inactivation by β-propiolactone and UV light. Viral titers were measured by plaque assays. After 10 h of inactivation with β-propiolactone, CELO titers fell by 4.12 ± 0.06 lg, whereas Fontes titers, by 4.20 ± 0.19 lg, suggesting that β-propiolactone is an effective inactivating agent. Exposure to UV light led to a reduction in CELO titers by 4.69 ± 0.89 lg and a reduction in Fontes titers by 4.44 ± 1.06 lg after 5 min. N-octyl-β-D-glucopyranoside added at the splitting step reduced CELO titers by 0.93 ± 0.15 lg and Fontes titers by 1.04 ± 0.12 lg, whereas tetradecyltrimethylammonium bromide led to a reduction in CELO and Fontes titers by 1.18 ± 0.17 lg and 1.12 ± 0.38 lg, respectively.
The Klebsiella pneumoniae bacterium is capable of causing the broad range of human nosocomial infections associated with antibiotic resistance and high mortality. Virulent bacteriophage therapy is one of the promising alternatives to antibiotic treatment of such infections. The study was aimed to isolate virulent bacteriophages effective against the relevant clinical K. pneumoniae strains, and to perform the molecular genetic characterization of these phages. Bacteriophages were isolated from the river water samples using the enrichment method. The whole-genome sequencing was performed on the MiSeq platform (Illumina). Three novel K. pneumoniae bacteriophages belonging to families Autographiviridae (vB_KpnP_NER40, GenBank MZ602146) and Myoviridae (vB_KpnM_VIK251, GenBank MZ602147; vB_KpnM_FRZ284, GenBank MZ602148) have been isolated and characterized. On the collection of 105 K. pneumoniae clinical strains, it has been found that bacteriophages vB_KpnP_NER40 and vB_KpnM_VIK251 have a narrow lytic spectrum (22% and 11%), which is limited to strains of the capsular types К2 and К20 respectively. In contrast, bacteriophage vB_KpnM_FRZ284 has a broad lytic spectrum (37%), causing the lysis of strains with different types of capsular polysaccharide. The phages are strictly virulent and have no genes encoding integrases, toxins or pathogenicity factors in their genomes. Genes of depolymerases, encoding the potential receptor binding proteins, have been found in the genomes of the capsular-specific bacteriophages vB_KpnP_NER40 and vB_KpnM_VIK251. The cocktail of three bacteriophages has lysed about 65% of the studied collection of K. рneumoniae strain and is potentially applicable for therapeutic purposes.
Nonspecificity of clinical, laboratory and instrumental manifestations of congenital infectious diseases, including viral infections, and the diversity of methods for etiological verification of pathogens define both the need to choose the optimal approaches to the diagnosis of this pathology, and the feasibility of testing for a broad range of etiologic agents in case of suspected congenital viral infection. The analysis of current guidelines, international consensus documents issued by specialists, and published results of some studies has shown that identification of the genetic material of the pathogen with the use of amniocentesis/ cordocentesis (for cytomegalovirus and parvovirus infections) or in the birth canal (for herpes simplex infection) is the key method for antenatal etiological verification of the widespread viral infections. During the postnatal period, molecular genetic testing is combined with serological diagnosis involving determining specific immunoglobulins M and G, as well as their avidity index.
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system involving autoimmune mechanisms. MS has been treated as a disorder mediated mainly by T cells for a long time. However, recent findings demonstrate that B lymphocytes are of crucial pathogenetic significance in MS. In patients with MS, B cells can possess both pro-inflammatory and anti-inflammatory effects. The paper reports the main mechanisms of B lymphocyte involvement in the pathogenesis of MS. Diagnostic value of assessing humoral immune parameters in individuals with demyelinating diseases and modern possibility of B cell function modulation are discussed.
Glycemic control is the biggest challenge for athletes with diabetes mellitus (DM) on insulin therapy. Done well, it can keep glycogen metabolism normal and allow performance improvement through adjustment of the insulin doses to the specifics of nutrition and exercising. In DM Type 1 and Type 2 patients, intense physical activity and resistance exercising, as well as interval training, enable optimal physiological adaptation during the training period and prove to be beneficial when the athlete does one-time exercise sets. But for athletes with DM on insulin therapy, keeping blood glucose at the optimal level is not the only important issue. It is also necessary to factor in the potential body temperature regulation disturbances that increase the risk of heat stress during training/competition, learn the effects the drugs used by athletes may have on the glycemic status, control electrolyte balance and dehydration, know how to execute the application for permission to use insulin for therapeutic purposes submitted to the anti-doping organization. The purpose of this review was to draw attention of sports medicine physicians and coaches to the above problems and to the need for wider use of the new DM control technology; help athletes with DM on insulin therapy continuously perform well and ensure their athletic longevity.
Numerous studies conducted in recent decades have generated vast amounts of knowledge on sport-related concussions. This review analyzes international data on pediatric and adolescent sport-related concussions. Drawing on the most recent research into the pathophysiology of brain concussions, the authors identify and discuss “pain points” associated with SRC, i.e. unsolved problems of diagnostic criteria, the use of modern neuroimaging modalities and promising biomarkers. Special attention is paid to the physiology of children and adolescents and predisposing factors important for developing adequate diagnostic and management strategies. The authors formulate problems that need to be solved in order to improve care for young athletes with brain concussions.
The search for highly sensitive and highly specific biomarkers of MS, including neuroimaging biomarkers, continues. One of such biomarkers is the central vein sign detectable on SW and T2-weighted MR images. The sensitivity and specificity of methods used for central vein sign detection vary. This article describes two clinical cases of patients with similar neurological symptoms which required making differential diagnosis between multiple sclerosis and secondary demyelination in the presence of a systemic disorder (systemic lupus erythematosus). In addition to routine MR sequences, we used SWI generated by a 3T scanner. The lesions with the central vein sign were counted; the proportion of perivenular lesions was determined. In the multiple sclerosis case, all the lesions were perivenular; the proportion of lesions with the central vein sign in the patient with secondary demyelination in the presence of systemic lupus erythematosus was 16.7%. The use of SW images improved the informative value of the analysis.
ISSN 2713-2765 (Online)