No 1 (2022)

Introduction. The article presents an epidemiological analysis of the prevalence and structure of acute chemical poisoning in the Northwestern region during the Covid-19 pandemic. The purpose of the study: to analyze the prevalence and structure of acute chemical poisoning among patients of a multidisciplinary hospital during the Covid-19 pandemic.

Materials and methods. In the course of the work, archival, monthly statistical data were used on the registration of persons hospitalized in the center for the treatment of acute poisoning of the named after I.I. Dzhanelidze Research Institute of SP in the period 2019–2020. The main method of the study was clinical and epidemiological, which includes an analysis of the intra-annual dynamics of the occurrence of acute chemical poisoning, based on monthly observations. In the statistical processing of the material, numerical characteristics of variables with an assessment of their accuracy and reliability were used, analytical methods aimed at constructing a time series model by autoregression and integrated moving average (ARIMA) were used. Nominal data were compared using the criterion χ² adjusted for continuity.

Results. The epidemiological analysis revealed the main trends indicating a decrease in the total number of admissions of patients with acute chemical poisoning to a multidisciplinary hospital during the Covid-19 pandemic (y = –106.25x + 17.16, R² = 0.7346). The data obtained indicate, first of all, a decrease in the income of persons with acute alcohol poisoning and higher alcohols, starting from April 2020, which, of course, was facilitated by the introduction of a strictly anti-epidemic regime in the GBU Research Institute of SP named after I.I. Dzhanelidze and the change in the conditions of hospitalization in medical institutions of St. Petersburg during the Covid-19 pandemic. The increase in the frequency of acute poisoning with medicinal substances (antipyretics, analgesics and sedatives) used for the purpose of self-treatment of the main symptoms of an infectious disease has attracted attention. The main problem for public health remains the increase in the number of cases of acute poisoning with narcotic substances from the group of synthetic cathinones, synthetic derivatives of opium, precursors of gamma-hydroxyoximabutyric acid.

Conclusion. Data on the prevalence of acute chemical poisoning during the Covid-19 pandemic (according to the multidisciplinary hospital) indicate changes in the frequency of their occurrence and structure. 

An increase in cases of admission of persons with poisoning with analgesics, antipyretics, psychotropic drugs with sedative effect was found in the analyzed time period.

Introduction. Acetaminophen exhibits hepatotoxicity in overdose, which is the leading cause of drug-induced liver failure. The aim of the research was to study early morphological changes in the liver of experimental animals under the influence of high doses of paracetamol and after correction with hepatoprotectors.

Materials and methods. The corrective effect of various drugs — ademetionine, ethylmethylhydroxypyridine succinate and oxymethyluracil after exposure to high doses of acetaminophen was studied. Acetaminophen was administered to experimental rats once intragastrically at a dose of 1 g/kg, animals received hepatoprotectors twice (after 1 and 24 hours) or four times (after 1, 24, 48, 72 hours) after the toxicant. Morphological studies of the liver of experimental animals were carried out.

Results. Pathomorphological changes were revealed on rat liver preparations after exposure to paracetamol, the most pronounced after 72 hours of exposure. Oxymethyluracil has a protective effect on the structure of the liver during acute exposure to high doses of paracetamol, comparable to the well-known drugs “Heptor” and “Mexidol”. In addition, the protective effect of oxymethyluracil appears earlier.

Limitations. Morphological studies of the liver of 90 white male rats were carried out for studying the corrective action of hepatoprotectors after acute exposure to high doses of acetaminophen and after double (after 1 and 24 hours) or quadruple (after 1, 24, 48, 72 hours) administration of ademethionine, ethylmethylhydroxypyridine succinate and oxymethyluracil, which allowed to determine an effective means to reduce the toxic effect of paracetamol on the liver.

Conclusion. The data obtained may have a certain practical value in terms of the prospective use of oxymethyluracil as an additional effective agent for reducing the toxic effect of paracetamol.

Introduction. A necessary condition for protecting an employee from gases with the help of filtering personal respiratory protection equipment (PPE) is the timely replacement of filters. Previously, the reaction of the sense organs to the ingress of gas into the mask was used for this. Due to unreliability, this method has been completely banned in all developed countries, since filter life is estimated under the worst expected conditions for scheduling filter replacement.

Materials and methods. We prepared the article using publications NIOSH, OSHA, Taylor & Francis, Springer, Journal of the ISRP, legal requirements of developed countries for the use of respirators, and other available publications. 

Results. The article describes problems and ways to solve them during scheduling, using mathematical modeling of the service life (single use of the filter), taking into account its advantages and disadvantages and problems in assessing the safety of reuse of cartridges.

Conclusion. The article contains an analysis of the sources of risk for workers using gas masks in Russian Federation; recommendations for its reduction are given. 

Introduction. The Organization for Economic Cooperation and Development (OECD) has developed the QSAR Toolbox software, which allows predicting the properties of chemicals including (eco)toxic based on the structure of the substance using mathematical statistics methods. The purpose of this work was to study the applicability of the OECD QSAR Toolbox software for calculating the acute aquatic toxicity parameters (LC₅₀ and EC₅₀) of chemicals necessary, for example, to determine the hazard class of chemical products according to GOST 32419-2013 “Classification of chemical products. General requirements” or to prepare a safety data sheet for products.

Materials and methods. The OECD QSAR Toolbox software version 4.4.1 (current for August 2021), documents, manuals and webinars of the OECD, the European Chemical Agency (ECHA), the Laboratory of Mathematical Chemistry of the University of Burgas, Bulgaria (the main software developer), articles.

Discussion of the results. The OECD QSAR Toolbox software version 4.4.1 allows calculating the acute aquatic toxicity parameters (LC₅₀, EC₅₀) of chemicals using trend analysis and read across, as well as automated and standardized workflows. About 50 chemicals with experimental data of LC₅₀ and EC₅₀ belonging to different hazard classes according to GOST 32419-2013, with different functional groups in the structure of the molecule, were selected for testing. Calculated values of LC₅₀ and EC₅₀ of chemicals were compared with the experimental data.

Conclusion. The OECD QSAR Toolbox software version 4.1.1 can be successfully used to calculate the acute toxicity parameters LC₅₀, Pimephales promelas, 96 h; LC₅₀ (EC₅₀), Actinopterygii, 96 h and LC₅₀, Daphnia magna, 48 h for a wide range of organic compounds, but is not applicable for inorganic substances, organometallic compounds, polymer molecules, chemicals containing metal ions.

Виктор Александрович Тутельян, академик РАН, профессор, доктор медицинских наук, научный руководитель Федерального государственного бюджетного учреждения науки «Федеральный Исследовательский центр питания и биотехнологии» (ФГБУН «ФИЦ питания и биотехнологии»), руководитель лаборатории энзимологии питания ФИЦ, руководитель кафедры гигиены питания и токсикологии Института профессионального образования ФГАОУ ВО Первый МГМУ имени И.М. Сеченова Минздрава России, иностранный член Национальной Академии Наук Республики Армения, член Европейской Академии естественных наук.