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Biomedical subjects

L V Baĭdun

Publications and source records attributed to L V Baĭdun.

At least 19 recordsLinked to original sources

[Automatic erythrocytometry in a robotized microscope MEKOS-Ts1].

Measurements of the form and size of erythrocytes are needed in the diagnosis of a number of diseases. However, such measurements, if made manually, are a labor-consuming and often inaccurate method, which ensures the determination of a very limited number of parameters. Hardware/software unit MEKOS-C1 enables an automated examination of blood smear, thus speeding up significantly the analysis and ensuring a more complete and accurate information. The possibilities of unit MEKOS-C1 were evaluated for the diagnosis of ovalocytosis. Blood smears of 19 patients from the Russian Pediatric Clinical Hospital, including 8 patients with inherited ovalocytosis, 1 patient with spherocytic ovalocytosis and 10 patients without the disease, were made use of Erythrocytes were isolated in the images of preparations and the contour of each cell was approximated by ellipse. The ratio between ellipse semi-axes served as a measure of erythrocytes' ovality. The mean ratio of semi-axes (RS) and the index of ovalocytosis (IO), i.e. a ratio of the mean maximum diameter to the mean minimal diameter, were calculated for each smear. Manual IO measurements were made in all preparations as a control. Since an additional error can enter the result because of the irregular smear nature and impossibility to standardize completely the technology of smear preparation, the data, obtained from two different smear parts and from parallel preparations, were compared. The reliability, stability and good reproducibility of the automated measurement results were demonstrated. The mean erythrocytes' RS correlated well with IO, obtained manually, and did not virtually differ from RS, measured in the automated manner. The mean RS value of erythrocytes, obtained from patients with inherited ovalocytosis, significantly differed from the control values, which is indicative of a high information density of the discussed parameter. Therefore, RS, when measured automatically, is a reliable and convenient characteristic of erythrocytes' ovality under the conditions of using the ordinary technique of smear preparation.

Adolescent↗

[Increased expression of monocytic cell adhesion molecules and formation of monocyte-thrombocyte aggregates in coronary restenosis].

AIM: To examine expression of superficial antigens by blood monocytes and granulocytes as well as the number of leukocyte-platelet complexes forming in in vitro activation in patients subjected to coronary angioplasty; to analyse changes in these parameters in coronary restenosis. MATERIAL AND METHODS: Membrane expression of leukocytic antigens and the number of leukocyte-platelet complexes after activation in the whole blood were measured by direct immunofluorescence and flow cytometry in 24 patients who have undergone stenting of coronary arteries. 14 of them had angiographically confirmed restenosis. RESULTS: The tests discovered high expression of integrins Mac-1 and VLA-4 by monocytes and elevated relative number of monocyte-platelet complexes in patients with restenosis vs those free of stenosis (1425 +/- 76 and 1195 +/- 71 r.u. for Mac-1, 87 +/- 7 and 65 +/- 6 r.u. for VLA-4, 47 +/- 4 and 29 +/- 3%, respectively, for monocyte-platelet complexes; p < 0.05 for all the indices). CONCLUSION: Coronary restenosis may result from elevated expression of adhesion molecules by monocytes manifest in activation of the cells in vitro.

Angioplasty, Balloon, Coronary↗

[The role of Mac-1 and ICAM-1 molecules in adhesion of cells on fibronogen and its degradation products].

Monocytic cell adhesion to immobilized fibrinogen and fibrinogen degradation products, and involvement of integrins Mac-1 and immunoglobulin-like ICAM-1 adhesion molecules in these processes were investigated. Fibrinogen cleavage with plasmin down-regulated adhesion of cells with predominant Mac-1 expression; in contrast, the attachment of ICAM-1-expressing was up-regulated. By means of function-blocking anti-Mac-1 and anti-ICAM-1 antibodies, and immobilization of known fibrinogen degradation products, it was shown that Mac-1 molecules mediated cell adhesion predominantly to fibrinogen, and its early degradation products, fragments X and Y, while ICAM-1 participated in cell attachment to X- and Y-fragments, rather than to intact fibrinogen or late degradation products, fragments D and E.

Cell Adhesion↗

[Evaluation of the pool of mature circulating lymphocytes in children with acute leukemia].

In children with acute leukemia, at the initial period of the disease the absolute number of T-lymphocytes is within the normal range, when the values of the total number of leucocytes is low or normal, and it is increased in cases with high initial leucocytosis. Dissociation of T-cell marker signs in the lymphocyte population has been revealed that evidences the presence of functionally defective T-cells in the circulation. The value of the relative content of E+ T-cells over 10% in the circulation is of prognostic significance.

Adolescent↗