Introduction. In the structure of occupational diseases associated with the effects of chemical factors, the pathology of the respiratory organs due to the action of dust, occupies the first place. Among the recommended methods of treating occupational dust pathology, there are no procedures for removing foreign particles from the respiratory tract aimed at eliminating the cause of the disease. Despite the effectiveness of total bronchoalveolar lavage in the treatment of professional dust bronchitis, the method has a number of disadvantages due to the need to use large volumes of saline solution, which can lead to undesirable side effects associated with water balance disorders in the body caused by the absorption of fluid by the lungs during the procedure. In this regard, attention is drawn to the possibility of using perfluorocarbon compounds with low bioavailability for the elimination of foreign microparticles from the lungs by bronchoalveolar lavage or total liquid ventilation (TLV). The study aims to give an experimental assessment of a possible method for the treatment of occupational lung diseases of dust etiology, based on the removal of dust foreign particles from the respiratory tract using perfluorocarbon compounds. Materials and methods. Scientists performed a study on male rabbits of the Soviet Chinchilla breed aged 3-4 months, weighing 2.8-3.6 kg. They used a device of their own design with an open circuit to carry out the procedure of TLV, in which the liquid "washed" the lungs and drained into a special container. Perfluorodecalin was used as a respiratory fluid. At the first stage, rabbits on TLV inhaled for 3 minutes microparticles of silica gel of the LL-254 brand (5/40 microns) marked with a luminescent indicator. At the second stage, after the end of inhalation, the rabbits of the control group continued to be on artificial ventilation with air, and the rabbits of the experimental group were transferred to the TVL for 5 minutes. At the third stage, artificial ventilation of the lungs with air was performed until the end of the action of the muscle relaxant and the restoration of independent breathing. Estimated indicators: the presence of luminous particles on the surface of the trachea, bronchi, on sections of lung tissue and in perfluorodecalin passed through the rabbit's lungs; histomorphological picture of the lungs; indicators of respiratory gases and acid-base state in arterial blood. Results. Elimination of silica gel from airways by TLV procedure was detected by luminescent visualization and histomorphologically. Complete recovery respiratory gases and acid-base status or arterial blood in one hour after procedure proved safety of TLV procedure. Conclusion. TLV procedure is able to remove foreign particles from the respiratory tract. The researchers proved the effectiveness of the procedure according to three criteria: presence of luminescent labeled particles in waste perfluorodecalin after TLV; decrease of luminescent labeled silica gel macroscopic visualization in trachea and bronchi; decrease of silica gel amount in lung tissue detected by microscopic histomorphological methothods; Perfluorodecalin application for foreign (including radioactive) particles removing from respiratory tract is more preferably than saline, because of saline lungs absorption that potentiate particles incorporation in tissue. Five-minutes TLV procedure does not induce markable disturbances of gas exchange monitored by respiratory gases and acid-base status or arterial blood. Complete recovery of these parameters was detected within one hour after procedure. Ethics. The scientists conducted studies involving laboratory animals in compliance with the necessary regulations (the Helsinki Declaration of 2000 on Humane Treatment of Animals and the "Rules for carrying out work using experimental animals" (Order of the Ministry of Health of the USSR No. 755 of 12.08.1977)). The protocol of the study was approved by the Ethics Committee of the Izmerov Research Institute of Occupational Health.
Introduction. One of the promising directions of creating fundamentally new submarines’ crews rescue methods is the usage of perfluorocarbon breathing fluids. The last study of liquid ventilation in hyperbaria was published in 1985. The current level of technology development open up new opportunities for the practical implementation of this direction. To determine further development direction of usage liquid ventilation technology and to understand the place of this technology in existing or prospective systems of assistance and evacuation from emergency submarines, it is necessary to analyze the causes of emergency situations on submarines and the conditions of fight for survivability. We devoted this study to determining possible scenarios for the use of liquid ventilation technology, as well as its place in the system of assistance and evacuation of crews of emergency submarines. We have devoted this study to determining possible scenarios for the use of liquid ventilation technology as well as its place in the system of assistance and evacuation of emergency submarines crews. The study aims to substantiate possible scenarios for the usage of liquid ventilation technology in the rescue of submarine crews in distress from an underwater position. Materials and methods. The following used materials were: publicly available literature data; regulatory documents defining the procedure for carrying out rescue operations in case of accidents on the submarine; own experimental data. The main research method was generalization and analysis. Results. The researchers have presented the analysis of literature data on accidents on submarines. There are three typical scenarios of the development of the consequences of accidents, each of which can be characterized by the impact of certain pathological factors on the body. We also have determined the frequency of their occurrence. The experts have presented the conditions of preliminary stay in the emergency compartment of the submarine, which directly determine the actions of the crew, as well as factors influencing the use of liquid ventilation technology and typical conditions for the use of the latter. The scientists have determined the conditions of preliminary stay in the emergency compartment of the submarine, which directly determine the actions of the crew, as well as factors influencing the use of liquid ventilation technology, and typical conditions for the use of the latter. The conditions for the use of liquid ventilation technology in case of accidents on the submarine are determined in accordance with possible scenarios. Conclusion. Methods of evacuation of crews from submarines using liquid ventilation technology can become a significant addition to the existing rescue system, expanding and opening up additional opportunities for rescue operations in conditions in which it is not possible to apply known methods.
Introduction. According to the literature data, the method of liquid ventilation for the prevention of decompression sickness (DCS) was proposed only with the condition of its initiation before compression, that excluded the physical basis of the disease - an excess of metabolically indifferent gas in the tissues. However, as the analysis shows, in most cases, the evacuation of the crew of an emergency submarine is aggravated by being in gases’ increased pressure environment. So the casualty tissues become obviously saturated with indifferent gas. Experimental confirmation of the possibility of rapid tissues’ desaturation of nitrogen during respiration by denitrogenizated and oxygenated in a normal conditions respiratory fluid (hereinafter - the method of liquid respiratory desaturation) was obtained on the biological model of DCS of Syrian hamsters. The study aim is an experimental substantiation of the possibility to use liquid respiratory desaturation as a method of preventing the development of decompression disorders. Materials and methods. Scientists have performed a study on 24 mature male Syrian hamsters weighing 165-185g, aged four months, using an experimental laboratory hyperbaric stand for temporary maintenance of small laboratory animals under high pressure of a gas or liquid medium with the possibility of switching from one medium to another in isobaric conditions.The research methodology is based on the assessment of the clinical presentation of decompression disorders and the results of ultrasound examination of gas formations in the heart, large veins and liver after the fast non-stop decompression, in the background of preliminary saturation of the animal's body with indifferent gas (nitrogen) by staying in the air under the pressure 0.6 MPa (60 MWC) for six hours. The effect on experimental groups animals deferens from the control group by the period of immersion and spontaneous breathing in the respiratory fluid (20, 30 and 40 minutes) before decompression. Results. The authors analyzed the clinical picture of acute decompression disorders. The degree of gas formation in small laboratory animals was assessed by researchers using ultrasound using a semi-quantitative method. Spontaneous breathing with the prepared liquid, lasting 30 minutes or more, made it possible to remove excess nitrogen from the body of animals of experimental groups, providing etiopathogenetic prevention of DCS before decompression. The article presents the data of morphological studies. Conclusion. Liquid respiratory desaturation is a method of preventing decompression disorders based on the removal of metabolically indifferent gases from the body during liquid respiration, in the presence of a stress gradient from tissues into the respiratory fluid. The method allows the metabolically indifferent gases' rapid desaturation from the body by liquid ventilation before/or during decompression, thereby creating conditions of ultra-fast decompression modes without the risk of decompression disorders.
Introduction. The creation of adequate models for studying the processes of human interaction with the environment is a key problem of modern experimental biology and medicine. This is due to the fact that both the results of the conducted studies and the recommendations developed on their basis depend on the choice of the biological object and the characteristics of the factor directly affecting it. It should be noted that errors related to both the discrepancy between the developed experimental pathology and the simulated conditions for humans, and the choice of a method for assessing the safety of xenobiotics are critical and can lead to serious consequences. The study aims to determine the existing trends in biomodeling and extrapolation of the results currently being implemented in experimental toxicology and medicine based on the analysis of literature data. Materials and methods. We have used forty five domestic and foreign scientific publications as materials. The research method was the analysis and generalization of the materials presented in scientific publications. Results. The scientists considered such components of extrapolation modeling as the creation of an adequate model, compliance with the principles of proper laboratory, as well as extrapolation of the obtained data to humans. We have given the definition of an experimental model of the disease as a condition developing in a laboratory animal under the influence of an etiological factor, which most fully reflects the main manifestations of the disease that arose on the basis of a common human and used biomodel of pathogenesis. We introduced the term "zero-order biomodels" and defined it as an object used for biomodeling and also presented a classification of zero-order biomodels. Conclusion. Currently, issues related to their standardization are of increasing importance in conducting biomedical research, which is reflected in the appearance of a large number of regulatory documents regulating not only the procedure for conducting them, but also the requirements for biological models used for these studies. However, despite the existing trends, the key point in conducting all studies was and still is the issues related to the extrapolation of the data obtained to humans. The conducted analysis suggests that new biological models (of the zero-order) are being actively introduced into the practice of biomedical research according to their characteristics fully corresponding to the prototype - human biological material obtained from various sources. A distinctive feature of these models is the absence of the need to extrapolate the results obtained to humans. The analysis shows that at present there are all prerequisites for conducting preclinical studies using almost the entire spectrum of biological models of the zero-order specified in this publication within the existing legal framework.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.