[Proton Transfer Reaction Mass Spectrometry of Exhaled Breath in Diagnostics of Heart Failure].

BACKGROUND: Exhaled breath analysis is one of directions in the search for novel biomarkers of chronic heart failure (CHF). According.

[Pathology diagnostics by human breath analyze].

Modern medicine experiences deficit of inexpensive rapid screening technologies despite progress in the development of diagnostic methods for various diseases. A promising approach is the analysis of exhaled air known to contain thousands of volatile organic substances whose composition differs considerably in health and disease. We isolated certain compounds that may be used as biomarkers of cardiovascular pathology (nitric oxide, carbon monoxide, pentane, isoprene, acetone). There is a variety of methods for the detection of substances in the exhaled air; such as gas spectrography, mass spectrometry, etc. However, ion mobility spectrometry appears the most suitable technique for the purpose of screening studies due to its high speed and sensitivity, small size of the apparatus, and possibility to measure trace amounts of the substances of interest. Possibilities to diagnose lung cancer based on exhaled air composition are considered.

[Effect of the level of free-radical lipid peroxidation on the ribonucleotide reductase activity of liver tissue]. / Vliianie urovnia svobodnoradikal'nykh protsessov okisleniia lipidov na ribonukleotidreduktaznuiu aktivnost' tkani pecheni.

The dynamics of RNA and DNA synthesis as well as the activity of free radical processes in rat liver during the first 40 hours after partial hepatectomy was studied. It was shown that RNA synthesis activation follows the activation of lipid peroxidation (LPO), whereas the DNA synthesis activation follows the decrease of the LPO level. These facts are suggestive of the dependence of the ribonucleotide reductase (RNR) activity on free radical processes. This observation was confirmed by a RNR activity analysis of regenerating liver homogenates. The activity peak was shown to precede the peak of DNA synthesis. Evidence for free radical RNR suppression was also obtained in direct experiments, using intact animal liver homogenates, to which a natural antioxidant (tocopherol) was added.

[Derivation of the working equations of a CO2-CO-H2O-H2-N2 gas mixture for the cathode space of an electrolyzer with solid electrolyte taking into account its oxygen extraction]. / Vyvod rabochikh uravnenii gazovoi smesi CO2-CO-H2O-H2-N2 dlia katodnogo prostranstva élektrolizera s tverdym élektrolitom s uchetom izvlecheniia iz nee kisloroda.

Equations of thermodynamic equilibrium of the gas mixture CO2-CO--H2O-H2--N2 for the cathode space of the electrolyzer containing a solid electrolyte with extracted oxygen taken into consideration were derived. Equilibrium partial gas pressures, thermal effect of reactions, theoretical voltage of dissociation (the system of equations included 11 unknown parameters) were determined. These parameters are functions of temperature, total pressure of the gas mixture, initial gas composition, and the coefficient characterizing the degree of oxygen transfer from the cathode cell to the anode cell of the electrolyzer.

[Relation between DNA transcription and repair in stress]. / Sootnoshenie transkriptsii i reparatsii DNK pri stresse.

Stress-induced DNA breaking may occur partially as a result of decrease in 5-methyl cytosine content. Poststressory activation of transcription was shown to follow the stimulation of the DNA repair synthesis. The processes studied involved two phases and were tissue-dependent.

[Comparison of the accuracy of DNA copying in the course of semiconservative and repair synthesis using an analysis of the distribution of radioactive precursors]. / Sravnenie tochnosti kopirovaniia DNK v khode polukonservativnogo i reparativnogo sinteza putem analiza raspredeleniia radioaktivnogo predshestvennika.

The analysis of 3H-thymidine incorporation into liver and heart DNA has shown the possible errors occurring during repair synthesis in pyrimidine oligonucleotides.

[Age-related characteristics of poststress DNA repair in the myocardium]. / Vozrastnye osobennosti poststressornoi reparatsii DNK miokarda.

It has been demonstrated that young and adult rats had age-associated differences in stress-induced lesions and in poststressor repair of DNA synthesis in the myocardium. In both age groups, the DNA repair systems perform an identical scope of work aimed at abolition of poststressor lesions with the difference that in young rats, the repair is completed 2 days and in adult rats 3 days after exposure to stress is discontinued.

[Determination of the nucleotide and isoplith composition of DNA by scanning thin-layer chromatograms in ultraviolet light]. / Opredelenie nukleotidnogo i izoplitnogo sostava DNK putem skanirovaniia tonkosloinykh khromatogramm v UF-svete.

The author studied the UV spectra of the bases and pyrimidine sequences of DNA after separation in thin layers of cellulose, and calculated the coefficients permitting the determination of nucleotide and isoplith composition of DNA from UV light reflection during thin-layer chromatogram scanning.

[Structural-functional analysis of single-stranded particles of rat liver DNA]. / Strukturno-funktsional'nyi analiz odnonitevykh uchastkov DNK pecheni krys.

A base composition of single-stranded DNA regions differed from those of total rat DNA mainly due to increase in content of 5-methylcytosine. Content of this base in the regions studied reduced with age and after cortisol administration. The single-stranded regions appear to shield the informative DNA sequences.

[DNA damage and reparative synthesis in various organs of the rat, induced by emotional-painful stress]. / Povrezhdenie i reparativnyi sintez DNK razlichnykh organov krys, vyzvannye émotsional'no-bolevym stressom.

Emotional-painful stress results in DNA single-strand breakage and repair synthesis activation in all the organs studied. The process is tissue-specific.

[Possibility of hydrocortisone induction of intertissue recombination of DNA fragments]. / Vozmozhnost' induktsii gidrokortizonom mezhtkanevoi rekombinatsii uchastkov DNK.

Incorporation of 3H-thymidine in DNA of different organs and blood of rats was studied in health and under the action of hydrocortisone. Based on the data obtained it may be suggested that there is a possibility of intertissular recombination of DNA fragments, which is increased under the action of hydrocortisone mainly in the liver.

[Changes in the primary structure of DNA in rat organs during the aging process]. / Izmenenie pervichnoi struktury DNK nekotorykh organov krys v protsesse stareniia.

Thin-layer chromatography was used to study the composition of bases and pyrimidine sequences of varying lengths (isopliths) in DNA of different organs of rats aged 1, 12 and 30 months. It was found that with age the isoplith composition of DNA in the organs under study changed towards the chaotic distribution. The composition of DNA bases changed with age towards enrichment with guanine-cytosine-vapors, which was particularly pronounced in organs marked by an age-related decrease of 5-methylcytosine in DNA.

[DNA metabolic characteristics of the rat brain in the process of developing a conditioned reflex]. / Osobennosti metabolizma DNK mozga krys v protsesse vyrabotki uslovnogo refleksa.

The time course of methylation and repair synthesis of DNA in the large hemispheres was examined in rats trained the conditioned reflex of active avoidance. The conclusion is made for the first time that excision demethylation of brain DNA play a role in the formation of the systemic structural track that forms the basis for temporary links.

[DNA changes in a nonischemic area of the rat myocardium in experimental myocardial infarct and its prevention]. / Povrezhdenie DNK v neishemizirovannoi zone serdechnoi myshtsy krys pri éksperimental'nom infarkte miokarda i ego preduprezhdenie.

DNA damage and repair in the nonischemic area of the heart were analyzed after experimental myocardial infarction to evaluate the effect on these processes of the beta-blocker inderal and lipid peroxidation inhibitor ionol. It was found that in the nonischemic area of the heart, DNA damage was manifested by the decreased polymerism averted to a significant degree by inderal and ionol which interfered with postinfarction activation of lipid peroxidation. Accordingly, inderal and, to a greater degree, ionol reduced postinfarction activation of DNA repair synthesis in the nonischemic area of the heart.

[Prevention of structural damage to myocardial DNA caused by emotionally painful stress by means of beta-adrenoreceptor and lipid peroxidation blockade]. / Preduprezhdenie narushenii struktury DNK serdechnoi myshtsy, vyzvannykh émotsional'no-bolevym stressom s pomoshch'iu blokady beta-adrenoretseptorov i perekisnogo okisleniia lipidov.

Emotional-painful stress was accompanied by an increase in the rates of depolymerization and of repairatory replication of heart muscle DNA. When the repairatory replication of DNA was repressed by actinomycin D, the rate of its depolymerization was simultaneously increased. A beta-adrenoreceptor blocking agent inderal and an inhibitor of lipoperoxidation ionol prevented the DNA depolymerization and activation of the polymer synthesis under the stressory conditions. These data corroborate the hypothesis that stress favors an increase in content of catecholamines, increasing the rate of lipoperoxidation and producing free radicals responsible for impairment of heart muscle DNA. In ontogenesis the multiple damage-repair cycles in DNA apparently lead to accumulation of genetic errors, which may be among the reasons of senescense.

[Myocardial DNA damage and repair in emotional-painful stress]. / Povrezhdenie i reparatsiia DNK serdechnoi myshtsy pri émotsional'no-bolevom stresse.

[Partial depolymerization of myocardial DNA was found to ensue within the first hours after termination of stress exposure. The depolymerization was accompanied by DNA synthesis repair manifesting both in in-vivo and in-vitro experiments. With time the repair of DNA synthesis decreased while its polymerism got recovered. The data obtained provide evidence in favour of the relationship between the stress-induced free radical activation and damage and subsequent DNA synthesis repair.