No abstract

Summary. Background: The specifics of occupational activities of firefighters is determined by exposures to both fire hazards and a combination of occupational risk factors of various nature significantly exceeding their standard values. Adverse chemical exposures rank first due to unpredictable toxic effects of combustion products from burning synthetic polymers. Yet, the most dangerous are low-temperature fires emitting a wide range of air contaminants including highly lipophilic, bioaccumulative and persistent dioxins. The purpose of the research was to study the relationship between various polymorphic variants of xenobiotic detoxification genes and blood lipid concentrations of dioxins in firefighters. Materials and methods: We measured average dioxin concentrations in ambient air at different stages of firefighting and in blood lipids of firefighters with different length of service using the analytical method of gas chromatography–mass spectrometry (GC-MS). The cumulative effect of dioxins was estimated in relation to polymorphic variants of xenobiotic detoxification genes of the first and second phases of biotransformation by determining polymorphisms, the main research method being polymerase chain reaction (PCR). Results: High concentrations of dioxins measured in ambient air at all stages of firefighting and in blood lipids of firefighters with a significant correlation with work experience indicate that inhalation is one of the main routes of exposure to dioxins and that these chemicals are occupational risk factors for this professional group. The analysis of the relationship between various polymorphic variants of xenobiotic detoxification genes and blood lipid concentrations of dioxins in the firefighters showed a higher blood level of dioxins in carriers of minor alleles. Conclusions: Genotyping of firefighters and identification of carriers of minor alleles of xenobiotic detoxification genes may contribute to timely preventive and rehabilitation measures aimed at elimination of adverse health effects of occupational exposure to dioxins.

Background: Firefighters are characterized by constant interaction with smoke and various combustion products, which, entering the body can, affect the state of the respiratory system. Objective: To study the relationship of the bioelemental status with changes in the functional state of the lungs in firefighters of the Ministry of Emergency Situations of Russia. Results: The study revealed an increase in a number of toxic microelements in firefighters by 2-5 times compared with persons not participating in fire extinguishing, as well as a decrease in the content of essential microelements in the studied hair samples. The connection of toxic trace elements (aluminum, silver, cadmium) with a decrease in the diffusion capacity of the lungs, broncho-obstructive changes and pulmonary fibrosis was shown. The study showed the relationship between the accumulation of the level of silver, aluminum and cadmium with noticeable changes in the functional state of the lungs.

Aim: To study intestinal microbiota and the parameters of oxidative stress in patients with metabolic syndrome (MS). Methods: The sample consisted of 50 patients with MS aged 55-65 years and residing in Saint Petersburg. The reference group consisted of 129 individuals of similar age without MS. The quantitative and qualitative composition of parietal intestinal microbiota was studied by gas chromatography with mass spectrometry using microbial markers in plasma. Oxidative stress the final oxidation products of protein molecules and lipids including 8-hydroxy-2-deoxyguanosine and malonic aldehyde were estimated. Nutritional antioxidants including vitamin E, unsaturated fatty acids etc. were assessed by chromatography mass spectrometry and mass spectrometry. Results: In the parietal layer of the intestine in individuals with MS, the total number of microbial markers is positively associated with the markers of the opportunistic microflora and lower levels of normal microflora. In MS patients, the ratio of normal microflora to conditionally pathogenic microflora is twice as low as in the reference group. Level of malonic dialdehyde and 8-hydroxy-2-deoxyguanosin were 48 % and 39 % higher in the MS group. Moreover, plasma concentrations of vitamin E and zinc were lower by 42 % and 80 % in patients with MS compared to the reference group. Сonclusions: The observed differences in the quantitative and qualitative composition of the parietal microbiota of the intestine in individuals with MS compared to the reference group suggest development of intestinal dysbiosis in MS patients. The intestinal dysbiosis is accompanied by oxidative stress manifested by an increase in the level of malonic dialdehyde in the blood plasma and 8-hydroxy-2-deoxyguanosine in the urine, as well as a decrease in the level of vitamin E and zinc in the blood plasma.

Relevance. Individuals of stressful professions, including the emergency response officers (firefighters and rescuers) of the Ministry of Emergency Situations of Russia, are prone to the early onset of circulatory system diseases (CSD). At in-depth examinations the CSD detection rate in EMERCOM response officers is above 10%. Earlier studies report that CSD risk factors are widespread among EMERCOM of Russia response officers. Therefore, it is relevant to identify the predisposition to CSD as soon as possible in order to maintain good health and longevity among highly qualified professionals of the Ministry of Emergency Situations of Russia.The pathophysiological mechanism underlying progression of atherosclerosis affects complicated interactions between vasculature, immune system and lipid metabolism. Evidence shows that intestinal microbiome exacerbates all compound risk factors for atherosclerosis, both directly and indirectly, thus playing an important role in CSD development.Numerous studies revealed that elevated levels of plasma homocysteine and other aminothiols strongly correlate with manifestations of vascular dysfunction in atherosclerosis, coronary heart disease, myocardial infarction, stroke, and thrombosis, which makes it possible to isolate homocysteine as an independent risk factor for CSD progression.Our objective is to evaluate intestinal microbiome metabolism indicators and plasma aminothiols as early CVD risk markers in emergency response officers of the Ministry of Emergency Situations of Russia.Methodology. A comprehensive clinical and laboratory examination was performed in 96 emergency response male officers of the Russian Ministry of Emergency Situations at a regular medical check-up in the outpatient center of the Nikiforov Russian Center of Emergency and Radiation Medicine, EMERCOM of Russia, St. Petersburg. The average age of response officers was (35.9 ± 0.8) years, with average work experience in the EMERCOM of Russia of (8.8 ± 0.5) years. All emergency response officers were split in 3 groups: group 1 included 56 practically healthy males, group 2 - 20 males with risk of CVD development, group 3 - 20 males with established CVD diagnosis. Chromatography with mass-spectrometric determination of short-chain fatty acids (SCFAs), trimethylamine N-oxide (TMAO) and aminothiols was performed in plasma samples from all examined patients.Results and analysis. TMAO level was elevated by 30 % in group 3 compared to group 1. Acetic acid level decrease by 32 % was found in group 2 and by 45 % in group 3 compared to group 1.Plasma valeric and butyric acids were decreased by 1.9 and 2.5 times respectively in group 3 compared to group 1, as well as by 2 times in group 3 compared to group 2. It was found that in group 3 cystine concentration was decreased by 30 % compared to group 1 and reduced glutathione was elevated by 2 times compared to group 2.Conclusion. The revealed changes in the level of SCFA, aminothiols and TMAO in emergency response officers of the Ministry of Emergency Situations of Russia indicate a metabolic imbalance, which expands our understanding of the interactions between the intestinal microbiome and human body. This is fundamentally important for CSD early diagnosis, prevention and correction in emergency response officers of the Russian Ministry of Emergency Situations.