Extreme Medicine

ISSN Print 2713-2757 ISSN Online 2713-2765

Extreme Medicine

SCIENTIFIC AND PRACTICAL REVIEWED JOURNAL OF FMBA OF RUSSIA

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Filimonova KS, Rogovskaya NYu, Beltyukov PP, Babakov VN

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.

Received: 2021-07-20

Published online: 2021-09-23

DOI: 10.47183/mes.2021.030

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VIEWS 2265

Gorodnichev RB, Kornienko MA, Kuptsov NS, Efimov AD, Bogdan VI, Letarov AV, Shitikov EA, Ilina EN

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.

Received: 2021-07-20

Published online: 2021-09-22

DOI: 10.47183/mes.2021.029

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VIEWS 2225

Blinova EA, Nikiforov VS, Yanishevskaya MA, Akleyev AV

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”.

Received: 2021-07-27

Published online: 2021-09-21

DOI: 10.47183/mes.2021.028

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VIEWS 1878

Kornienko MA, Kuptsov NS, Danilov DI, Gorodnichev RB, Malakhova MV, Bespiatykh DA, Veselovsky VA, Shitikov EA, Ilina EN

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.

Received: 2021-07-19

Published online: 2021-09-18

DOI: 10.47183/mes.2021.027

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VIEWS 2115

Klyuchnikov SO, Feshchenko VS, Zholinsky AV, Tarasova MS, Slivin AV, Efimov PV

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.

Received: 2021-07-20

Published online: 2021-09-17

DOI: 10.47183/mes.2021.026

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VIEWS 2006

Savushkina OI, Malashenko MM, Cherniak AV, Krjukov EV, Sinitsyn EA, Zykov KA

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.

Received: 2021-07-19

Published online: 2021-09-16

DOI: 10.47183/mes.2021.025

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VIEWS 2219

Kholina EG, Bozdaganyan ME, Strakhovskaya MG, Kovalenko IB

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.

Received: 2021-07-19

Published online: 2021-09-11

DOI: 10.47183/mes.2021.024

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VIEWS 2189

Kotikova AI, Blinova EA, Akleyev AV

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).

Received: 2021-07-21

Published online: 2021-09-03

DOI: 10.47183/mes.2021.023

Comments 0

VIEWS 1897