[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.

[The identification investigation of the material evidence of biological origin after multifactorial exposure]. / Identifikatsionnoe issledovanie veshchestvennykh dokazatel'stv biologicheskogo proiskhozhdeniia posle mnogofaktornogo vozdeistviia.

The possibility of investigating pieces of material evidence of biological origin after exposure to various factors is evaluated. The possibility of detecting proteins of liquid media of human organism by electrophoresis in polyacrylamide denatured gel is investigated. The method is intended for identification of biological material in a state of grave destruction. Methodology of such studies is proposed. The data indicate that the structural integrity and qualitative composition of the spectrum of main serum proteins are retained after combined exposure to damaging factors and complete destruction of blood cells.

[Effect of O-hydroxylamine on the transforming DNA from Bacillus subtilis. Correlation of chemical modifications with genetic consequences]. / Deistvie O-metilgidroksilamina na transformiruiushchuiu DNK Bacillus subtilis. Korreliatsiia khimicheskikh izmenenii s geneticheskimi posledstviiami.

The action of methoxyamine (MA) on B. subtilis transforming DNA (50 degrees C, pH 4,5 and 6,0, 1 M MA) was studied. The rate of cytosine residues modification in DNA is 250 times less than in monomer (rate constants for DNA are 1,5 X 10(-1) min-1 at pH 4,5, and 2,5 X 10(-6) min-1 in the first 300 hours of treatment at pH 6,0). At pH 4,5 the rates of cytosine (I) conversion into N4-methoxycytosine (II) and into 6-methoxyamino-5,6-dihydro-N4-methoxycytosine (III) are constant (II/III ratio is about 2,1). At pH 6,0 the II/III ratio smoothly increases from 1,0 to 1,6 (200 and 900 hours of treatment) due to a decrease in the product III accumulation rate. The frequency of MA-induced mutations shows a bell-shaped dependence on time with maxima (approximately 10%) at 80 (pH 4,5) and 500 (pH 6,0) hours of treatment. In both cases approximately 10% of cytosine residues are modified. These results suggest that either compound III is efficiently removed from the transforming DNA, or its presence does not arrest the DNA replication.

[Products of laser photolysis of thymine and their transformation in chemical hydrolysis of polynucleotides to the bases]. / Produkty lazernogo fotoliza timina i ikh prevrashcheniia v usloviiakh khimicheskogo gidroliza polinukleotidov do osnovanii.

Some main products of laser photolysis and gamma-radiolysis of thymine were shown to undergo subsequent transformations during DNA hydrolysis by formic acid to the bases. The method has been developed for the quantitative determination of the character and the degree of thymine transformations under the effect of laser- and gamma-radiations with a reference to the end-products of the irradiated thymine hydrolysis.