Effect of different cryopreservation regimens on Ehrlich carcinoma growth.

The freezing rate is a decisive factor in determining the purpose of using low temperatures, i.e., for cryoablation or cryobanking of tumor cells. The research aim was to determine effect of different cryopreservation regimens on Ehrlich carcinoma (EC) growth in vivo and subpopulation composition of the formed ascites. The previously cryopreserved with slow and rapid rates EC cells were cultured in peritoneal cavity (PC) of mice for 7 days. Absolute number of cells in the PC, the subpopulation composition of tumor with flow cytometry using CD44 and CD24 markers were determined. Immediately after warming, a significant redistribution of EC subpopulation composition with a decreased content of the most tumorigenic CD44high cells after both freezing regimens was found. Culturing in vivo for 7 days contributed to the restoration of EC subpopulation composition, but with some a decrease in the tumor growth intensity when slow cooling was used. Rapid cooling contributed to significant inhibition of tumor growth with a reduced number of CD44+ and increased CD24+ cells. None of the cryopreservation regimens resulted in a complete elimination of tumorigenic CD44high tumor cells. The freezing rate determines the preservation of the subpopulation composition of the EC and intensity of its growth in vivo.

BONE REGULATORY MECHANISMS DESTRUCTION IN EXPERIMENTAL CHRONIC KIDNEY DISEASE.

The aim of our study was to investigate the role of intercellular mediators ­ interleukin-1 receptor antagonist (IL-1 RA), interleukin-17 (IL-17), receptor activator of nuclear factor kB ligand (RANKL) and osteoprotegerin in the mechanisms of metabolic regulation of renal and bone tissue on model of violations of bone remodeling in chronic kidney disease (CKD). It was found a significant increase in the content of cytokines IL-1 RA (4,207 ± 0,546 pg/ml), IL-17 (33,944 ± 0,938 pg/ ml), osteoprotegerin (28,338 ± 1,223 pg/ml) and RANKL (0,184 ± 0,018 pmol/l) in the serum of animals in violation of bone remodeling in CKD compared with the contents of the studied cytokines in animals in the control group (2,529 ± 0,132 pg/ml, 28,166 ± 0,526 pg/ml, 21,588 ± 0,763 pg/ml and 0,131 ± 0,006 pmol/l, respectively) (P<0.05). The obtained correlations reflect the relationship between regulation of bone remodeling and the development of inflammation in CKD. The imbalance between pro- and anti-inflammatory cytokine plays an important role both in the development of CKD and in processes of bone remodeling.

[The analysis of dosage inaccuracy and its minimization modes].

The article deals with the analysis of factors impacting dosage inaccuracy and input of this inaccuracy into total inaccuracy of analysis. The total dosage inaccuracy includes both the value of inaccuracy mentioned in the technical passport of dosage device and inaccuracy values occurring at all stages of dosage during implementation of technique. The characteristics of dosage devices and their merits and shortcomings are taken into account. The article substantiates the choice of types of dosage devices to be implemented in the laboratory research. The modes of errors elimination and inaccuracy minimization were analyzed against the perfectly calibrated and totally corresponded to passport data device of air transfer dosage.