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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Abdraimova NK, Shitikov EA, Gorodnichev RB, Kornienko MA

Staphylococcus aureus is a bacterial pathogen that is frequently associated with drug resistance and causes serious infectious diseases. The challenge in treating staphylococcal infections arises not only from the strains resistance to antibacterial drugs but also from the bacteria's capacity to form biofilms. As an alternative to traditional antibiotic therapy, phage therapy, employing virulent bacteriophages, is being explored. Research on bacteriophage's effectiveness against S. aureus encompasses both individual use and their combination with antibiotics. The combined approach appears most promising, enhancing therapeutic efficacy substantially through the synergistic action of both the antibiotic and the phage. This review discusses the effects of using both agents together and the methodologies for their evaluation. It summarizes the latest in vitro and in vivo research on the combined approach against S. aureus, including experiments focused on biofilm elimination. Special emphasis is placed on clinical case studies in treating patients.

Received: 2023-10-20

Published online: 2023-12-31

DOI: 10.47183/mes.2023.058

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VIEWS 267

Kozyrev EA, Babachenko IV, Orlov AV, Martens EA, Nikitina EV, Tian NS, Orlova ED

Community-acquired pneumonia (CAP) is a major cause of pediatric morbidity and mortality. Currently, there is no common approach to determination of CAP severity in children, which hampers early diagnosis and treatment of the disease. The study was aimed to determine clinical and laboratory predictors of severe CAP in children under 4 years of age. Analysis of clinical data, parameters of complete blood count (CBC), C-reactive protein (CRP) using nonparametric methods for hypothesis testing, univariate correlation analysis, cross-tabulation (Statistica 10.0), logistic regression, and ROC analysis (SPSS Statistics 20.0) was performed in 72 children aged 1 month to 3 years 11 months admitted to hospital due to CAP. Severe CAP was diagnosed in 16.7% of children. Causes of severe CAP included respiratory distress (moderate — 58.3%, severe — 16.7% of cases) and sepsis (25%). We identified significant clinical predictors of severe CAP: vomiting (OR 4.2), tachypnea (OR 28.3), chest wall retractions (OR 6), wheezing (OR 4), and the absence of rhinitis (OR 0.21). Isolated assessment of the CBC and CRP did not allow to predict CAP severity. We have developed a prediction model predicting severe CAP in children under 4 years of age based on the presence of rhinitis, tachypnea, as well as leukocyte count (sensitivity and specificity 91.7%). Thus, currently the main cause of severe CAP in children under 4 years of age is respiratory distress, in which wheezing predominates. Physical examination with an emphasis on detection of rhinitis and respiratory distress is essential for diagnosing severe CAP. The use of a pneumonia severity prediction model may contribute to improvement of management of CAP in patients under 4 years of age.

Received: 2023-07-23

Published online: 2023-12-31

DOI: 10.47183/mes.2023.056

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VIEWS 282

Gorodnichev RB, Kornienko MA, Bespiatykh DA, Malakhova MV, Krivulia AO, Veselovsky VA, Bespyatykh JA, Goloshchapov OV, Chernenkaya TV, Shitikov EA

The growing proportion of antibiotic-resistant Klebsiella pneumoniae strains raises challenges to the healthcare system and requires the development of alternative treatment options. Bacteriophage therapy is one of such options. The study was aimed to isolate and describe bacteriophages effective against K. pneumoniae strains of clinically significant capsular types. The bacteriophages were isolated from the sewage and river water samples using the enrichment culture technique. The spectrum of lytic activity of the phages was tested on the collection of K. pneumoniae clinical isolates (n = 279). The studied bacteriophages lysed 52.8–100% of K. pneumoniae strains of respective capsular types: phage VKV295 lysed 100% of strains with the capsular type KL1, SAA231 — 52.8 of strains with KL2, NNK-G4 — 100% of strains with KL39, VSG32 — 66.7% of strains with KL41, NKA196 — 87.5% of strains with KL47, Rappa3 — 87.5% of strains with KL57, PEA128 — 95.5% of strains with KL64, and ChM-G5 — 69.6% of strains with KL102. Whole-genome sequencing and subsequent bioinformatic analysis revealed that the phages belong to the Autographiviridae family and are classified into three genera.The lytic spectrum of phages was limited to specific capsular types due to the presence of specific receptor-binding proteins, polysaccharide depolymerases. The isolated bacteriophages were strictly virulent, did not carry harmful genetic determinants, and had a specific host range, making them applicable in therapeutic practice for combating antibiotic-resistant infections caused by K. pneumoniae.

Received: 2023-11-01

Published online: 2023-12-31

DOI: 10.47183/mes.2023.060

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VIEWS 271

Terekhov AG, Pankrusheva TA, Chekmareva MS, Turenko EN, Artyushkova EB, Mishina ES, Grigoryan AYu, Myatechkin AA

Currently, treatment of contaminated skin wounds aggravated by ischemia of superficial soft tissues is a problem that presents certain difficulties. The search for the new ways of treatment and drugs possessing a multidirectional effect is a relevant problem. In this study, we aimed to explore the peculiarities of wound evolution and the effectiveness of the designed combination of medicines and magnetic therapy in a contaminated skin wound case. For the experiment, we divided male Wistar rats into 3 groups and modeled a contaminated skin wound in each of the animals. In the first group, no treatment was performed, in the second, we used the developed combination (benzalkonium chloride, dexpanthenol, pentoxifylline and carboxymethylcellulose sodium salt, combined with magnetic therapy), in the third — ointment with dioxomethyltetrahydropyrimidine + chloramphenicol and magnetic therapy. Planimetry, acid-base balance registration, measurements of microhemocirculation and local temperature of the wound bed underpinned monitoring assessment of the wounds. At the end of the study, the wound area in the second group was 10.7 and 3.7 (p < ; 0.05 ) times smaller than in the first and third groups, respectively, and healing rate — 2.6 and 1.3 (p < 0.05 ) times faster. The maximum values of microhemocirculation and the lowest pH were registered in the second group. Thus, combination of drugs and magnetotherapy we designed promoted healing of a contaminated skin wound, which allows recommending this treatment method for further study at the preclinical level.

Received: 2023-11-09

Published online: 2023-12-31

DOI: 10.47183/mes.2023.065

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VIEWS 246

Pikina AS, Golubinskaya PA, Ruchko ES, Kozhenevskaya EV, Pospelov AD, Babayev AA, Eremeev AV

Despite the prospects of the approach to cell therapy of cartilage damage in humans involving autologous chondrocytes, similar technologies are just beginning to be introduced into medical practice in the Russian Federation. In this regard, the development of biomedical cell products (BCPs) for cartilage tissue repair is quite topical, while the use of organoid technology is the most close to the native tissue conditions. According to requirements of legislation of the Russian Federation, it is necessary to assess biodistribution characterizing migration potential of the cells, their tropism for body tissues following implantation within the framework of preclinical trials. The study was aimed to assess biodistribution of novel BCP based on human chondrocytes in the form of chondrospheres after subcutaneous implantation in Balb/c nude mice. Implantation to 12 mice was performed during the first phase, along with administration of saline to 12 control animals. Weighting and follow-up were conducted for 90 days. Then mice were withdrawn from the experiment to collect samples of organs and tissues for histological analysis of the implant, estimation of its viability, integration. During the second phase biodistribution was assessed by PCR in order to detect human DNA in the organ and tissue samples. Chondrospheres successfully integrated in the tissues surrounding the inoculation zones and formed cartilage tissue. No significant (p < 0.05) changes in weight were reported. No human DNA found in chondrosphere implantation zones was detected in the samples collected from other organs and tissues. BCP demonstrated no biodistribution across other tissues and organs of mice 90 days after implantation, which suggested that the product developed was safe.

Received: 2023-11-05

Published online: 2023-12-31

DOI: 10.47183/mes.2023.057

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VIEWS 254

Sharagin PA, Tolstykh EI, Shishkina EA

The red bone marrow (RBM) exposure due to bone-seeking radionuclides can lead to grave medical consequences. In particular, the increased risk of leukemia in people exposed due to contamination of the Techa River in 1950s is associated with the RBM exposure due to 89,90Sr. Improvement of the internal RBM dosimetry methods includes the development of computational phantoms that represent 3D models of the skeletal sites. Modeling radiation transport within such phantoms enables estimation of conversion factors from the radionuclide activity in the bone to the RBM dose rate. This paper is an extension study focused on generating a set of computational phantoms representing skeletons of individuals of different ages. The aim was to develop a computational phantom representing a 5-yearold child for internal RBM dosimetry from incorporated beta emitters. The phantoms of the skeletal sites with active hematopoiesis were created using the original Stochastic Parametric Skeletal Dosimetry (SPSD) method. With this method, every such site represented a set of smaller phantoms of simple geometric shape. RBM distribution across the skeleton, bone size, characteristics of bone micro-architecture, as well as density and chemical composition of the simulated media (RBM, bone) were determined based on the published data. As a result, a computational phantom of the major skeletal sites with active hematopoiesis representing a 5-year-old child was generated that included 43 phantoms of bone fragments. Linear dimensions of phantoms were within 3–75 mm. Micro-architecture parameters varied greatly: BV/TV ratio —13–52%, Tb. Th. — 0.09–0.29 mm, Tb. Sp. —0.48–0.98 mm.

Received: 2023-10-23

Published online: 2023-12-31

DOI: 10.47183/mes.2023.061

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VIEWS 264

Lipatov VA, Lazarenko SV, Severinov DA, Denisov AA, Chupakhin EG, Aniskina EN

Various local hemostatics (based on collagen, gelatin, cellulose, etc.) are used to stop bleeding from parenchymal organs of the abdominal cavity. In the context of an acute in vivo experiment, this study aimed to comparatively assess the time and volume of bleeding from a trauma of abdominal cavity's parenchymal organs covered with a new collagen-based spongy hemostatics combined with Na-CMC. We used new multicomponent polymer sponge implants (MPSI) based on marine collagen and carboxymethyl cellulose sodium salt, Na-CMC; the components were mixed in the ratios of 15/85, 25/75, 50/50. Hemostatic activity of the samples was assessed by bleeding time and blood loss volume. For the experiments, rats underwent laparotomy and resection of the left lobe of liver (series 1) and lower pole of spleen (series 2). In both series of experiments, the controlled parameters (bleeding time and blood loss volume) were smallest in group 6, where the MPSI were 50/50 Na-CMC/collagen. The hypothesis of higher efficacy of composite local hemostatic agents (namely, made of Na-CMC and deep-sea squid collagen) in cases of trauma of the parenchymal organs was confirmed experimentally, and same experiment has also shown that collagen in the composition of MPSI boosts bleeding arrest (for liver injury, the smallest blood loss and hemorrhage control time was 41 s, for spleen injury — 57 s, respectively; p ≤ 0.05).

Received: 2023-11-11

Published online: 2023-12-31

DOI: 10.47183/mes.2023.063

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VIEWS 261

Gulko SV, Babadjanova GYu

Latex, made from Hevea brasiliensis sap, is the material used to make many medical products, including catheters, balloons and gloves. Hundreds of allergens from natural rubber latex have been identified, and 15 of them were numbered, from Hev b1 to Hev b15. Natural proteins in rubber cause both asymptomatic sensitization and type I IgE-mediated hypersensitivity. Treatment of latex makes use of chemical antioxidants that can also bring about type IV hypersensitivity reactions. Latex allergy is one of the most common causes of anaphylaxis in the operating room, and its prevalence has been growing since 1980s, together with the popularity of latex gloves. It is a well-known problem among medical professionals, with gloves and inhaled aerosol particles being the sources thereof. This study aimed to review the current scientific research and practical data in this only partially investigated area. In addition, increasing the awareness of doctors and patients minimizes the existing risks of latex allergy.

Received: 2023-11-08

Published online: 2023-12-31

DOI: 10.47183/mes.2023.064

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VIEWS 238