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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Shkaeva IE, Dulov SA, Nikulina OS, Solnceva SA, Zemlyanoi AV

To date, there have been no exposure standards for air concentrations of 1,4-dichlorohexafluorobutene (DCHF) in the work areas. The study was aimed to assess the toxicity of DCHF and to evaluate health hazard in acute, subacute, and chronic experiments. It was found that the substance was highly hazardous, DL50 in mice after intragastric injection was 79.0 mg/kg, СL50 was 229.0 mg/m3, and in rats these values were 86,0 mg/kg and 670,0 mg/m3. In animals, DCHF had a moderate local irritative effect on animal skin and ocular mucous membranes, as well as the skin resorptive effect. The 18.2 mg/m3 threshold limit concentration for a single inhalation exposure to DCHF was defined based on the changes in behavior responses and blood parameters. The 30-day subacute inhalation experiment revealed the pronounced cumulative effect of the substance. The 4-months chronic inhalation study showed that the exposure of experimental rats to 16.8 mg/m3 concentration of DCHF resulted in impaired function of central nervous system and cardiac activity, altered hematologic, biochemical, acid-base, and blood gas values, as well as in morphological alterations in lungs, which persisted after the 30-day recovery period. The chronic exposure threshold defined for DCHF was 2.2 mg/m3, and the defined no observable effect level was 0.24 mg/m3. Based on the study results, the maximum permissible concentration of DCHF in the air of the working area of 0.2 mg/m3 was confirmed and approved, the substance was assigned hazard class 2, vapor + aerosol + (specific protection of skin and eyes required). Gas chromatographic method using electron-capture detection for determination of DCHF mass air concentration in the work areas has been developed and approved.

Received: 2021-05-29

Published online: 2021-06-23

DOI: 10.47183/mes.2021.014

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VIEWS 2114

Kamilova TA, Golota AS, Vologzhanin DA, Shneider OV, Scherbak SG

Current oncology and oncohematology treatment methods allow more patients to successfully survive the disease. However, afterwards, most survivors have to deal with a wide range of symptoms and side effects and need rehabilitation. Personalized rehabilitation programs for such patients employ various methods of physical medicine. Physical activity is an important component of the cancer patients' treatment and rehabilitation. It improves their functional health, specifically — physical performance, cognitive function, psychological health, and makes the quality of their lives better. Physical activity increases muscle strength, alleviates the radiation and chemotherapy side effects and relieves fatigue. Personalized exercise programs are employed to monitor patient's condition and exercise tolerance. Physical and cognitive rehabilitative interventions are performed simultaneously as part of interdisciplinary rehabilitative care, so this approach can have a synergistic effect. It is necessary to factor in contraindications when prescribing regular physical activity, exercise and other methods of rehabilitation, otherwise they can lead to clinical complications.

Received: 2021-05-29

Published online: 2021-06-21

DOI: 10.47183/mes.2021.013

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VIEWS 2393

Sterlikov AV, Kurilenko YuV, Voronkov AA

External quality control in the form of interlaboratory comparisons (ILCs) is an important criterion of the testing laboratory competence. The study was aimed to summarize the approaches to developing objects for proficiency testing (OPT) based on physical simulation of acoustic noise sources, airborne ultrasound, vibration, and the practice of their use for ILC. Analysis of the OPT effectiveness based on physical simulation of factors, the test benches (TBs), was performed based on their testing and certification results, as well as on the results of appropriate ILCs. The results of using TB as OPT are considered for the following factors: acoustic noise, airborne ultrasound, and vibration. When measuring acoustic noise, TB played back the acoustic noise record with high stability. ILC involving measurement of airborne ultrasound was performed the same way, however, the frequency of the acoustic signal being reproduced was in the range of 11–22 kHz. TBs, based on a manual mechanized tool and a platform equipped with electromechanical agitator, were developed for ILC involving the measurement of local and general vibration. Stability of vibration generated was provided by means of the automated system for maintaining the set level with feedback and proportional integral derivative (PID) controller. When arranging and performing ILCs involving measurement of noise and vibration, a crucial role is played by the methods developed specifically for ILCs, allowing one to take into account all the conditions that affect the measurement results.

Received: 2021-05-27

Published online: 2021-06-18

DOI: 10.47183/mes.2021.012

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VIEWS 2225

Laptev DS, Protasova GA, Petunov SG, Radilov AS, Chepur SV, Gogolevskiy AS, Myasnikov VA, Tyunin MA, Smirnova AV

The development of coronavirus infection outbreak into a pandemic, coupled with the lack of effective COVID-19 therapies, is a challenge for the entire pharmaceutical industry. This study aimed to assess the treatment and preventive efficacy of the amino acid-peptide complex (APC) in male Syrian hamsters infected with SARSCoV-2 (intranasal administration of 26 μl of the virus culture, titer of 4 × 104 TCD50/ml). In a modeled COVID-19 case, APC administered for treatment and preventive purposes reduced lung damage. Compared to the positive control group, test group had the lung weight factor 15.2% smaller (trend), which indicates a less pronounced edema. Microscopic examination revealed no alveolar edema, atypical hypertrophied forms of type II alveolocytes, pulmonary parenchyma fibrinization. The macrophage reaction intensified, which is probably a result of the APC-induced activation of regenerative processes in the lung tissues. Spleens of the animals that received APC for therapeutic and preventive purposes were less engorged and had fewer hemorrhages. The decrease of body weight of the test animals that received APC for treatment and prevention was insignificant (p < 0.05), which indicates a less severe course of COVID-19. Administered following a purely therapeutic protocol, APC proved ineffective against SARS-CoV-2 post-infection. Thus, APC-based drug used as a therapeutic and preventive agent reduces pulmonary edema and makes morphological signs of lung tissue damage less pronounced in male Syrian hamsters infected with SARS-CoV-2.

Received: 2021-05-21

Published online: 2021-06-16

DOI: 10.47183/mes.2021.011

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VIEWS 2415

Poddubnyi IV, Tolstov KN, Fedorova EV, Trunov VO, Khanov MM, Malashenko AS, Sytkov VV, Mager AO, Ranshakov AS

Pediatric testicular masses are rare pathologies. Many physicians, facing such masses for the first time, have trouble choosing the algorithm of assessment and surgical treatment tactics. Extent of surgery and surgical approach depend directly on preoperative assessment results. The clinical case of the incident testicular mass surgical treatment in a 15-year-old boy is reported. The patient underwent laboratory and instrumental examination, the results of which confirmed a benign lesion. Based on the data obtained, the organ-sparing surgical approach was selected. An assessment algorithm, treatment tactics for testicular mass based on the data obtained, advisability and safety of the organ-sparing treatment approach are reported.

Received: 2021-05-10

Published online: 2021-06-05

DOI: 10.47183/mes.2021.010

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VIEWS 2228

Aldobaev VN, Mikhina LV, Present MA

Low molecular weight compounds targeting chaperone proteins Hsp90 and Hsp70 have opened up a new avenue in the therapy of neoplasms. In 2020, we tested 3 Hsp70 inhibitors from the class of 4-aminopiperidine derivatives for their antitumor activity on in vivo models. The list of the tested compounds included N-(2-chlorobenzyl)-N-ethyl-1-(2-(methylthio)pyrimidin-4-yl)piperidin-4-amine (compound 1), 4-((methyl(1-(2-(methylthio)pyrimidin-4-yl) piperidin-4-yl)amino)methyl) benzonitrile (compound 2) and N-(2,6- dichlorobenzyl)-1-(1-(2-(ethylthio)pyrimidin-4-yl)piperidin-4-yl)-N-methylmethaneamine (compound 3). The aim of this study was to compare the efficacy of 4-aminopiperidine derivatives in vivo using the models of transplantable murine L1210 lymphocytic leukemia and B16 melanoma. Compounds 2 and 3 used in combination with cyclophosphamide exhibited high cytotoxic activity (р = 0.05) against L1210 leukemia (an 80-82% increase in survival time) and B16 melanoma (98-99.7% tumor growth delay). For L1210 lymphocytic leukemia, compounds 2 and 3 used in combination with cyclophosphamide fell into the low (+) therapeutic potential category. For B16 melanoma, compounds 1, 2 and 3 used in combination with cyclophosphamide fell into either low (+) or moderate (++) therapeutic potential categories. On the whole, the tested doses of the compounds used in combination with cyclophosphamide hold promise for the therapy of L1210 leukemia and B16 melanoma in mouse models. Our findings confirm the potential of low molecular weight Hsp70 inhibitors for combination chemotherapy against cancer.

Received: 2021-02-13

Published online: 2021-03-21

DOI: 10.47183/mes.2021.009

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VIEWS 2315

Torubarov FS, Bushmanov AYu, Zvereva ZF, Kretov AS, Lukyanova SN, Denisova EA

Ensuring safety of the facilities employing radiation and nuclear hazardous technologies is a priority task for medical organizations serving these facilities. To perform safely at their jobs, it is important for the personnel of nuclear facilities (NF) to have their central nervous systems functioning flawlessly. Certain categories of nuclear industry workers are required to undergo compulsory annual medical examinations (ME) and psychophysiological examinations. This study aimed to develop a concept of psychophysiological examination of NF personnel allowing to assess the central nervous system's functional status. The study involved three groups of nuclear corporation employees (male) counting 720, 364 and 24 people aged from 46 ± 5.3 to 49 ± 6.1 years. The report describes the suggested concept of psychophysiological examination of the specified category of workers, discusses goals, objectives and the procedure of such an examination at all stages of compulsory ME, covers the developed hardware and software sets. The proposed methodological approach is evaluated through consideration of the results of psychophysiological examination of the specified category of workers.

Received: 2021-02-19

Published online: 2021-03-20

DOI: 10.47183/mes.2021.008

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VIEWS 2244

Karmishin AM, Borisevich IV, Skvortsova VI, Goryaev AA, Yudin SM

Popular SIR models and their modifications used to generate predictions about epidemics and, specifically, the COVID-19 pandemic, are inadequate. The aim of this study was to find the laws describing the probability of infection in a biological object. Using theoretical methods of research based on the probability theory, we constructed the laws describing the probability of infection in a human depending on the infective dose and considering the temporal characteristics of a given infection. The so-called generalized time-factor law, which factors in the time of onset and the duration of an infectious disease, was found to be the most general. Among its special cases are the law describing the probability of infection developing by some point in time t, depending on the infective dose, and the law that does not factor in the time of onset. The study produced a full list of quantitative characteristics of pathogen virulence. The laws described in the study help to solve practical tasks and should lie at the core of mathematical epidemiological modeling.

Received: 2021-02-16

Published online: 2021-03-19

DOI: 10.47183/mes.2021.007

Comments 0

VIEWS 2362