Biopolymer gels as components of protective medium for cryopreservation of spermatogonial stem cells.

Biopolymer gels attract a lot of attention in a field of biothechnology due to their excellent compatibility and degradation. Their application is also promising for cryopreservation of spermatogonial stem cells (SSCs) which is so necessary to preserve the fertility of young patients. The aim of the study was to determine the effectiveness of biopolymer gels as a component of cryopreservation medium for SSCs of immature rats at the stage of exposure to cryoprotectants.

[Long-term storage of industrial microbial strains].

Morphofunctional characteristics of industrial microorganisms belonging to different genera, species, and strains were investigated after 15 to 20 years of storage in liquid nitrogen. The taxonomic position of microorganisms, the cell physiological state prior to storage, and the cryoconservation regime were found to affect microbial cryoresistance. Protective media, density of cell suspensions, freezing rate, and heating temperature are the parameters important for development of efficient technologies for cryoconservation of industrial microorganisms at -196 degrees C.

[Preservation of Pseudomonas putida bacteria at low temperatures].

We have found that the mode of cooling, composition of cryopreservation medium, original concentration of cells and storage temperature affect viability of Pseudomonas putida bacteria during low-temperature preservation. We have elaborated the conditions of preservation, providing for a high survival of bacteria, namely: one-stage cooling with the rates of 30, 40 degrees C/min or immersion into liquid nitrogen in the culturing medium with addition of sucrose, glycerol or dimexide in the concentration of 0.5 M; storage temperature is -80 degrees C divided by -196 degrees C.

[Calcium-transporting system of erythrocytes in psoriasis].

The activity of Ca-ATPase and permeability of erythrocyte membrane for calcium in patients with psoriasis were studied with the aim to reveal disturbances in the calcium membrane transport under psoriasis. In the presence of endogenic activators the mean values of the maximal Ca-ATPase activity of erythrocyte membranes in patients with psoriasis and in healthy people have no essential differences and make up 264 +/- 12 and 244 +/- 10 mumol P/1 cells per 1 min, respectively. The rate of 45Ca accumulation in erythrocytes under inhibition of Ca-ATPase in patients suffering from psoriasis is by 64% higher than in healthy people.