[Is there interrelationship between percentage of hemolysis and clots in samples of venous blood?].

The most failures in the process of laboratory analysis occur at the pre-analytical stage. The percentage of samples of blood serum with hemolysis and percentage of samples of EDTA of whole blood with clots are largely applied as indices of quality of venous blood sampling. The analysis of data from 28 laboratories established no relationship between percentage ofsamples with hemolysis and percentage of samples with clots. Prior to implementation of more large-scaled studies, the level less than 1% of samples with hemolysis can be accepted as a minimal level of quality of blood sampling and the level less than 0.4% of samples of total blood with clots can be accepted as a minimal level of quality ofpreparation of samples after blood drawing from vein for analysis using hematological analyzers. both indices can be applied for estimating efficiency of measures concerning amelioration of quality of procedure of blood drawing from vein. By all appearances, the ideal sample for control of quality of blood drawing in the nearest future can become sample of blood drew from vein into vial with citrate for analysis using modern coagulometric analyzer. This sample can become a source for calculation of several indices of quality of venous blood drawing (hemolysis, clots, vial filling and violation of ration sample-anticoagulant).

[The latex agglutination with video digital registration: the enhancement of diagnostic significance of conventional technique].

The rapid semiquantitative latex-tests, because of their analytic characteristics and convenient application, became widespread in the practice of laboratory diagnostics. Though, in spite of high sensitivity and specificity, their diagnostic effectiveness is lower that it could be mainly because of the impossibility to document the results of latex agglutinative re4actions and to manage the objective quality control. The application of systems of video digital registration permits to enhance the clinical significance of these analyses. By means of scanner systems (control and program complex "Expert Lab") the image of analytic objects is received with the results of latex agglutination reaction. The application of program techniques (the programs "Expert Lab - Agglutination" and "Expert Lab - Agglutination - Micros") in data processing permits to get the precise qualitative characteristics of active reactions, to ensure the automatic interpretation of results and gives an opportunity to proceed with the internal laboratory quality control. The saving of analytic object image in computer memory after termination of reaction favors the formation of data base, the implementation of retrospective evaluation of obtained results, additional consultations in dubious cases, including on-line. The application of complex "Expert Lab" permitted to develop the miniaturizes matrix systems permitting to decrease the withdrawal of latex reagents, to increase the productivity of analytical stage of operation preserving all analytical characteristics of method.

[Analytical characteristics micromatrix semiquantitative method used in serial tests with video digital registration].

A multiplex analytical system has been developed to carry out microformat latex agglutination tests with video digital registration. The system makes it possible to apply less than 1 microl drops of latex and samples in the matrix format to a carrier and to make the test in 30 points at once, as well as to record and to interpret the results of the test, by keeping analytical information for each sample. Comparison of the results of determination of the serum levels of C-reactive protein, rheumatoid factor, and antistreptolysine in the system developed by the authors with the results obtained in the macroagglutination test by the immunoturbidimetric technique leads to the conclusion that the methods are comparable. The proposed type of a latex agglutination test based on a matrix approach and miniaturization assures efficient production and the quality of laboratory studies.

[Use of a scanner to register the results of enzyme immunoassay in the standard microplates].

Whether a commercially available scanner might be used as a vertical photometer of 96-well microplates for enzyme immunoassay (EIA) was studied. The analytical characteristics of the scanner in this regard were assessed, by comparing the findings with the respective photometric data obtained by a "VICTOR" EIA analyzer. It is concluded that the scanner registration system in combination with "Expert-Lab EIA" may be used in all types of EIA. The scanner system provides additional possibilities as compared with the conventional photometric analyzers.

[A scanner-based system for documentation, objective assessment, and recording of the results of latex-agglutination tests].

The present paper describes the use of the scanner "Expert-Lab Agglutination" system to record the results of latex-agglutination tests in making a reaction on the lids of 96-well immunoassay plates. The described system provides a possibility of having a primary image of all tests carried out on a carrier. Software offers the prospect of contrasting the images of individual and control samples, increasing the size of images, and comparing the latter. The use of special image treating techniques may also yield objective figures characterizing the rate of a reaction. The possibility of archiving primary information and retrospectively appraising the correctness of the result of an analysis at any required moment is of fundamental importance to the latex-agglutination test.

[A functionally important Tyr-89 residue in Saccharomyces cerevisiae pyrophosphatase. II. A possible role in the mechanism of enzyme action]. / Funktsional'no vazhnyi ostatok Tyr-89 pirofosfatazy S. cerevisiae. II. Vozmozhnaia rol' v mekhanizme deistviia fermenta.

Earlier it has been demonstrated that inactivation of inorganic pyrophosphatase (PPase) of S. cerevisiae by 7-chloro-4-nitronbenzofurasane is due to modification of Tyr89. The effect of pH and active center ligands on this reaction has been studied. It was found that pK for Tyr89 does not exceed 8.5; the phosphate-metal complex binding to the high affinity center protects Tyr89 from inactivation. Activating ions (Mg2+ and Zn2+) do not influence the inactivation, whereas the PPase inhibitor, Ca2+, enhances this process after saturation of the high affinity binding site. Saturation of two binding sites with Ca2+ has a protective effect on the enzyme. An increase in the rate of Tyr89 binding to the inhibitor in the presence of low concentrations of Ca2+ is due to the decrease of Tyr89 pK. The data obtained suggest that Tyr89 is located near the high affinity binding site for phosphate. The high reactivity of Tyr89 and its tight binding in the active center point to the presence of a hydrogen bondage with the substrate and suggest a role of a proton donor whose acceptor is the product of the enzymatic reaction, i.e., phosphate.