[MODERN METHODS OF PHYSICAL-CHEMICAL RESEARCH IN GASTROENTEROLOGY PRACTICE: THE EXPERIENCE OF INTERACTION].

UNLABELLED: The aim of this work was to assess the potential of some physical and chemical methods for studying erythrocytes and blood serum in gastroenterological practice by the example of colorectal cancer (CC). MATERIALS AND METHODS: A total of 26 persons with various stages of colorectal cancer and 16 healthy (control group) were examined. Parameters of erythrocytes and blood serum were investigated by light microscopy, dielectrophoresis in a non-uniform alternating electric field (DEF in NUAEF), terahertz spectroscopy, ellipsometry, Raman-spectroscopy. RESULTS: Polymorphism of erythrocytes, rigidity, viscosity, indexes of aggregation and destruction were significantly higher in patients with CC and polarizability, amplitude of erythrocyte deformation in NUAEF being lower than those in the controls. The study of erythrocytes by terahertz spectroscopy revealed the low levels of amplitude transmittance over the whole frequency range in CC patients compared to the controls. The increasing of refractive index, degree of heterogeneity of thin films obtained from the serum in CC patients were observed in considering the ellipsometric parameters. We found a significant increasing of the concentration of antigens to CD24 at the early stage of the disease. The areas of some peaks in Raman spectra were significantly lower in patients with CC compared to the healthy ones, it is possible due to a carotin deficiency. Most of the studied parameters were correlated with the stage of the disease. A set of optical methods for studying blood serum compared with those of histology and radiological methods of diagnosis showed their high sensitivity and specificity, positive and negative predictive value (80 % and above). CONCLUSION: The obtained results of the pilot study demonstrate the prospects of using physical and chemical methods of research of erythrocytes and blood serum for early diagnosis, stage of disease and monitoring the effectiveness of treatment of CC.

Novel SOI-Biosensor Topology for the Detection of an Acute Myocardial Infarction Marker - Troponin I.

A biosensor based on field-effect transistors on silicon-on-insulator structures (SOI-biosensor) is a high-potential device for detection of biological molecules, for instance, such as troponin I; the biosensor allows conducting label-free real-time analysis. The aim of the study is the development of SOI-biosensor design for detection of acute myocardial infarction marker - troponin I. A notable feature of this design was the integration of two grounding electrodes directly onto the biosensor surface, which effectively nullified the static potential of the liquid sample and minimized physical breakdowns of biosensor elements. Materials and Methods: The highly specific anti-troponin I DNA aptamer was used as a receptor for specific detection of protein marker. Aptamer immobilization on the biosensor surface was carried out by physical adsorption. The analyzed range of target troponin I molecules concentration in the sample varied within 10-11 to 10-9 mol/L, mirroring clinical levels observed in myocardial infarction cases. During the experiment, a constant voltage of Vds=0.15 V was maintained. Results: The developed SOI-biosensor successfully detected target troponin I molecules at a concentration of 10-11 mol/L. The detection process exhibited an effective time of approximately 200-300 s per sample. Moreover, analysis of the detection process revealed a noticeable decrease in current within the source-drain circuit, indicative of the negatively charged complex formed by troponin I and anti-troponin I DNA-aptamer at the "liquid sample-nanowire" phase interface.

[Rationale for using essential phospholipids in chronic diseases of the liver: the dynamics of electric and viscoelastic parameters of erythrocytes].

Under supervision there were 38 men (age from 36 till 57 years) with diffuse hepatic diseases (DHD) in stadia of hepatitis, 27--in dynamics of treatment of essential phospholipids. Is experimentally established: structure-functional erythrocyte characteristics by methods of dielectrophoresis, thin-layer chromatography correlate with lipid and phospholipid composition of red cell membranes. The low level of phospholipids in erythrocyte membranes and direction of changes in their fractional composition in the DHD is the basis for the use of essential phospholipids. Against the background of therapy noted a significant increase in amplitude of deformation, polarizability, capacity, speed of movement of red blood cells to the electrodes and lower levels of generalized indicators of viscosity, rigidity, electrical conductivity, index of aggregation and destruction.

[Theoretical and experimental study of the effect of membrane pores on spectra of amplitudes of polarization of a cell].

Spectra of amplitudes of polarization of erythrocytes, yeast cells, and latex particles in the range of 1-10 Hz were investigated by the method of dielectrophoresis. Positive dielectrophoresis of erythrocytes and yeast cells the frequency range of 60 - 100 Hz was revealed. The theoretically positive dielectrophoresis was evidenced by the occurrence of channels across the cell membrane and bacterial cell wall.

[Highly pathogenic avian influenza: a new pandemic threat and possibilities to resist it].

The review presents modern data on outbreaks of avian influenza subtype H5N1 and the incidence of the infection in animals, birds, and humans. The authors adduce data on the resistance of influenza A virus to physical and chemical factors. Factors making avian influenza A virus potentially capable of causing human pandemia are considered. The review also deals with public health possibilities in the event of influenza pandemia, and measures directed towards lowering its negative social and economic consequences.