Background: Through measurements of the heart rate variability (HRV) accompanied by the pertinent biomarker assays, the effects of nicotine and byproducts derived from alternative nicotine delivery systems (ANDS) on the autonomic nervous system (ANS) and hormonal system have been investigated. Methods: HRV was studied in a group of volunteers (17 people), involving non-smokers, i.e., who never smoked before (11), ex-smokers (4) and active smokers (2). ANDS and smoking simulators, including regular, nicotine-free and electronic cigarettes; tobacco heating systems; chewing gums and nicotine packs of oral fixation (nic-packs), were used. Blood pressure, levels of stress hormones in saliva and catecholamines in the blood were also monitored. Results: HRV analysis showed relatively small changes in HRV and in the other studied parameters with the systemic use of nic-packs with low and moderate nicotine contents (up to 6 mg) compared to other ANDS. Conclusions: The HRV method is proven to be a promising technique for evaluation of the risks associated with smoking, dual use of various ANDS and studying the biomedical aspects of smoking cessation. Nic-packs are shown to be leaders in biological safety among the studied ANDS. A sharp surge in the activity of the sympathetic division of the ANS within the first minutes of the use of nicotine packs implies that nicotine begins to act already at very low doses (before entering the blood physically in any significant amount) through fast signal transmission to the brain from the nicotinic and taste buds located in the mouth area.

The microbiota is a key factor in maintaining the homeostasis of the human body. The intestinal microbiota has not been given due attention for a long time. Today, a high-quality and reliable study of the microbiota is possible due to chromatography-mass spectrometry of microbial markers. The study allows detecting bacteria, microscopic fungi, and viruses.

The OBJECTIVE was to determine the possibility of using chromatography-mass spectrometry to select causal treatment for patients with pleural empyema.METHODS AND MATERIALS. The analysis of the results of examination and treatment of 207 patients with pleural empyema for the period from 2017 to 2018 was done. All patients underwent bacteriological examination, twenty patients from them underwent chromato-mass-spectrometric examination of pleural exudate.RESULTS. Patients were transferred to a specialized thoracic hospital from other medical institutions, where they received a course of empirical antibacterial therapy and drainage of the pleural cavity was performed. Bacteriological examination of the contents of the pleural cavity was positive in 112 (54.1 %) patients. The leading pathogens were gram-negative bacteria isolated from the contents of the pleural cavity in 45 % of patients with closed and 63.5 % – open pleural empyema. Polyantibiotic-resistant stocks of P. aeruginosa (30.4 %), K. pneumoniae (19.6 %) and A. baumannii (12.5 %) prevailed, which remained sensitive to polymyxin and, in some cases, to amikacin. In 25 (22.3 %) patients, micromycetes of the genus Candida were found. No growth of anaerobic microflora was detected. Chromato-mass-spectrometric examination of pleural exudate revealed markers of 30 taxa of bacteria, viruses and fungi that exceeded the norm by more than two times. Markers of gram-negative bacteria were not detected. The proportion of anaerobic microorganisms was 76.6 %, with the highest concentration found for bacteria of the genus Clostridium and Eubacterium.CONCLUSION. The choice of causal treatment for patients with pleural empyema is difficult due to the negative culturing from the contents of the pleural cavity in 45.9 % of patients, as well as the discordance between the results of bacteriological and chromato-mass-spectrometric studies. Diagnostic methods for detecting pathogens of pleural empyema require further improvement.

To date, the study of the relationship between the intestinal microbiome and COVID-19 infection remains a topical issue. As is known, the gastrointestinal tract is the entrance gate for SARS-CoV2 infection, and the prevalence of gastrointestinal manifestations reaches 17,6%. The conducted studies testify in favor of changes in the composition of the intestinal microflora in patients with COVID-19 compared with patients without a respiratory infection, their influence on the course and prognosis of the disease is being studied.

Introduction. Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. Non-alcoholic steatohepatitis (NASH), a clinically progressive morphological form of NAFLD, ranks second in the list of reasons for liver transplantation in the adult population. In the pathogenesis of this disease, metabolism and distribution of free fatty acids (FFA) play an important role. A large number of studies have established that the level of FFA in peripheral blood directly correlates with the severity of NASH, but it is still unclear what effect fluctuations in the profile of fatty acids (FA) in the liver have in steatohepatitis.Aim. Study of changes in the profile of fatty acids in the liver of laboratory animals with experimental non-alcoholic steatohepatitis.Materials and methods. The study was carried out on 17 white outbred male rats, which were randomized into two groups – intact (n = 6) and control (steatohepatitis) (n = 11). Steatohepatitis was modeled by 12-month use of a hypercaloric high-fat diet against the background of hypodynamia. The content of fatty acids in the liver was determined in the reaction of methanolysis and extraction with a hexane mixture of their methyl esters. The LC was separated by gas chromatography-mass spectrometry. Calibration for quantitative calculation was carried out with deuterated tridecanoic acid. The content of saturated and monounsaturated higher FAs, their aldehydes and hydroxy derivatives, as well as sterols were studied.Results and discussion. A total decrease in the content of FFA in the liver of animals with steatohepatitis was revealed. The most significant decrease occurred mainly in the class of monounsaturated fatty acids and cholesterol. Also, a significant decrease in the activity of Δ9-desaturase, a key enzyme in the synthesis of monounsaturated FAs from their precursor with the same carbon chain length, was revealed, which was manifested by a significant decrease in their amount in the liver. There were no statistically significant changes in the levels of aldehydes and hydroxy acids between the study groups, as well as in the level of sterols (except for cholesterol, the content of which decreased significantly).Conclusion. Thus, in the liver of rats with steatohepatitis caused by a combination of a hypercaloric diet and hypodynamia, statistically significant changes in the profile and concentration of fatty acids were found in comparison with healthy animals. The demonstrated shifts in FA composition may reflect both adaptive and pathological changes in the liver of animals with NAFLD and require further study.