Antioxidants increase the cryoresistance of GM-CFC.

The influence of antioxidative drugs on the cryopreservation of human bone marrow cells was studied. The viability of bone marrow cells was tested after freezing and thawing from--196 degrees C by the growth of GM-CFC in agar culture. The results suggest the ability of antioxidants to protect stem cells against damage caused by freezing and thawing.

[Experimental studies of the sterilization of transplantation material with peracetic acid].

Experimental investigations for sterilization of prepared transplantation material without aseptic conditions were carried out with peracetic acid of different aqueous and alcoholic dilutions. This chemical germicide is qualified yet for the sterilization of tendinous tissue but not for bone tissue (spongiosa and compact substance). The different cellular structures of the test objects condition this behaviour likely.

[Test of the vitality of hypothermically stored and cryopreserved rat hearts following in vivo coronary perfusion].

Experiments were carried out on cryopreservation of rat hearts. Viability of hearts perfused with cryoprotectant containing solutions as estimated by a short-time connection of rewarmed hearts with the circulation of a recipient animal. ECG, contraction and reflow from the perfused heart were measured.

[A method for the cryopreservation of thrombocytes].

By using dimethylsulfoxide (0.7 mol/l) a technique of cryoconservation of thrombocyte concentrates was elaborated, with own material-technological possibilities being taken into consideration. In comparison to fresh thrombocytes the results of parameters tested in vitro reveal a mean functional ability of 50%.

Contractility and membrane potential of cryopreserved auricle fragments from rat hearts after pretreatment with selenium.

Both contractility and membrane potential are suitable as viability assays of cryopreservation from rat heart muscle tissue. A pretreatment of donor animals with sodium selenite improves the survival of cryopreserved auricle fragments measured by contractility and membrane potential.

[Pretreatment of donors with sodium selenite-a method for the conditioning of tissues for cryoconservation].

Investigations about the protective effect of the pretreatment of albino rats with different concentrations of sodium selenite in sodium chloride solution were carried out. Albino rats, serving as a control group, had only a pretreatment with sodium chloride solution. The following results were obtained: 1.

[Protective effect of selenium compounds in the freeze preservation of erythrocytes].

The influence of sodium selenite, selenomethionine and sodium selenite with tocopherols in combination on the survival of cryopreserved erythrocytes was investigated. Percent hemolysis is marked decreased after a three-hour incubation of the whole blood with addition of selenomethionine as well as sodium selenite with tocopherole in combination before cryopreservation. The protective effect is attributed to the antioxydative and membrane stabilizing effectiveness of selenium and tocopherol.

Some aspects for the further improvement in cell cryopreservation.

According to theoretical considerations and to results of own experimental investigations in heart muscle fragments of adult rats the authors are of opinion that more attention should be attributed to the cryoprotective medium as a whole, i.e. not only to the proper cryoprotectant, but to the other components of the cryoprotective medium as well.

Successful cryopreservation of auricle fragments from rat hearts at -196 degrees C.

The influence of electrolyte composition and glucose concentration of a cryoprotective medium on the survival of auricle fragments from adult rat hearts after storage at -196 degrees C was investigated. Using a K+-, Mg++-, Ca++-rich solution with increased glucose concentration, a high rate of surviving fragments was found after cryopreservation.

[Induction of lymphocytotoxic antibodies through transplantation of preserved allogeneic skin in mice].

The authors report investigations on inducing lymphocytotoxic antibodies by transplanting allogenic skin grafts in mice after different kinds of preservation. Immunogenic effect was found at the following test conditions: storage of the graft for 4 weeks at -196 degrees C without cryoprotection, storage for 1 day at -38 degrees C, and storage at room temperature after lyophilization immediately after removal. No immunogenity was found after storage for 3 weeks at -38 degrees C, and uncertain immunogenity after storage for 4 weeks in 4 per cent formaldehyde solution.

[Studies on the antigenicity of variously preserved skin].

The authors have investigated a model of second-set-rejection after allo-transplantation of chemically preserved skin by different methods. The relative increase of weight of regional lymph nodes as well as the production of lymphocytotoxic antibodies served as additioned indicators of senzitation. All regimes of preservation used in this model of second-set-rejection have been responsable for a decrease in antigenity.