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The negative impact of tobacco smoke on the human body is due to a wide range of harmful substances including volatile organic compounds (VOCs). Some VOCs of tobacco smoke metabolize in human organism into mercapturic acids (MAs). The determination of the amount of MAs in readily available biological fluids, for example in urine, allows to assess the level of exposure of these VOCs in a particular person. It is useful to assess the impact of individual VOCs on the body together with the assessment of the intake of nicotine. The intake of nicotine can be determined by the content of its metabolites in the urine, in particular by the content of trans-3′-hydroxycotinine (tH-Cot). A joint assessment of the concentrations of trans-3′-hydroxycotinine and MAs in urine allows obtaining selective information about effects of different VOCs and nicotine on the smoker’s body. We have developed a liquid chromatography-mass spectrometry (LC-MS) method for simultaneous quantifying of tH-Cot and three MAs: N-Acetyl-S-(3-hydroxypropyl)cysteine (HPMA), N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (HMPMA), N-Acetyl-S-(2-cyanoethyl)-L-cysteine (CEMA). We used this method to quantify the levels of MAs and tH-Cot in the urine of a group of 15 smokers just before and 5 days after smoking cessation. For all studied compounds, we have found statistically significant changes in concentration on the fifth day of smoking cessation. The method developed can be used to jointly assess the levels of exposure to nicotine and VOCs in the study of various tobacco products. [ABSTRACT FROM AUTHOR]

Helicobacter pylori (H. pylori) infection is tightly associated with gastrointestinal disorders such as chronic gastritis, peptic ulcer, gastric MALToma, and gastric cancer. Decreased antibiotic susceptibility in H. pylori is a worldwide problem. Our objective was to determine in vitro antimicrobial susceptibility of H. pylori isolates obtained from gastric mucosa biopsies of children with H. pylori-associated gastroduodenal diseases using disk-diffusion method. A total 76 biopsy specimens were studied; antibiotic susceptibility was assessed in case of 30 children in whom H. pylori was revealed by bacteriology. The maximum resistance of H. pylori isolates was revealed to clarithromycin with nine resistant isolates (30.0%). The rate of resistance to metronidazole, amoxicillin, furazolidone, tetracycline, and levofloxacin was 23.3, 33.3, 16.7, 25.0, and 16.7%, respectively. Multidrug resistance was detected in 20.0% of H. pylori strains. The high prevalence of resistance to antibiotics used in eradication therapy is becoming a problem which needs eradication therapy regimen use based on regional H. pylori resistance rates. [ABSTRACT FROM AUTHOR]