[Use of hydroxyethyl starch as a cryoprotective medium during platelet storage at low temperatures]. / Zastosowanie hydroksyetylowanej skrobi jako srodka krioochronnego podczas prezechowywania krwinek plytkowych w niskich temperaturach

The effects of HES and HES + DMSO used as cryoprotective media for storage of human platelets in liquid nitrogen and vapor phase of liquid nitrogen were studied. Solution of 6% and 15% HES with molecular weight ranging from 65,000 to 250,000, and 10% DMSO were used. The criteria accepted for evaluation of the efficiency of these cryoprotective media were: 1. platelet counts, 2. participation of platelets in the processes of hemostasis measured in vitro by the ability of platelets to release adenine nucleotides (ATP + ADP) after thrombin stimulation. It was found that 15% HES is a more effective cryoprotective medium than 6% HES. The use of 15% HES + 10% DMSO gave similar results as the use of 10% DMSO alone.

[Effect of cytostatic drugs on the metabolism of incubated human blood platelets]. / Badania nad wplywem leków cytostatycznych na metabolizm inkubowanych krwinek plytkowych czlowieka

Degranol was chosen from the group of cytostatic drugs and Cytosar and Flucrouracil from the group of antimetabolites for investigations on the effects of cytostatics on the metabolism of thrombocytes. After isolation from blood collected on ACD fluid thromtocytes were suspended in own plasma containing EDTA and the cytostatic agent in a concentration of 6 x 10(-3)M and were subjected to incubation during 3 hours at 37 degrees C. After incubation the thrombocyte count, the levels of nucleotide compounds, and adenine nucleotides (ATP + ADP) released by thrombocytes under the action of thrombin, and the activity of dehydrogenase glucose-6-phosphate and lactic dehydrogenase were determined. The results of these determinations showed that only Degranol as a compounds belonging to the group of alkylating cytostatics caused lowering of ATP level (by about 30%) in the incubated cells. The drugs from the group of antimetabolites caused no significant changes in the studied parameters.

[Effect of cytostatic agents on the metabolism and ultrastructure of blood platelets in man]. / Wplyw leków cytostatycznych na metabolizm i ultrastrukture krwinek plytkowych czlowieka.

The effect of cytostatic drugs used in the treatment of haemopoietic system diseases: cerubidin, hydroxyurea. cytosine arabinoside and their combinations on the platelet count, platelet ultrastructure, metabolic activity and participation in the processes of haemostasis was investigated. The experiments were done using two concentrations of the drugs: clinical corresponding to the maximal single dose and a fivefold as high concentration, It was found that the investigated cytostatic agents and their cominations in the first concentration had no effect of the platelet count, level of free nucleotides, activity of glucose-6-phosphate dehydrogenase and lactic dehydrogenase, and on the reaction of adenine nucleotides release from the platelets induced with thrombin. Using the higher concentration of the drugs it was observed that cerubidin and the combination of cytostatic agents tested changed the shape and ultrastructure of the platelets.

[Storage of human bone marrow at - 196 degrees C]. / Przechowywanie ludzkiego szpiku kostnego w temperaturze - 196 degrees C

The paper contains a description of the method of human bone marrow storage at -196 degrees C using DMSO and glycerol as cryoprotective agents. In the light of determinations of the count of nucleated cells, their viability, myelograms and blastic transformation of lymphocytes it was found that DMSO is a more effective cryoprotective agent than glycerol for storage of human bone marrow at low temperatures.

[Storage of platete concentrates at +4 degrees C and +22 degrees C]. / Przechowywanie koncentratów krwinek plytkowych w temperaturze +4 degrees C i +22 degrees C.

The relationship between the conditions of platelet preservation and their ultrastructure, metabolic activity, and the ability to carry out physiological functions was studied. It was found that storage of platelet concentrates at +4 degrees C for 72 hours reduced the number of platelets, changed their shape decreased the ATP level and the ability of release of adenine nucleotides in response to thrombin. The platelet at +22 degrees C for 72 hours preserved the initial number, normal ultrastructure, intact metabolic activity and the ability of participation in heamostasis processes.

[Clinical usefulness of blood platelets cryopreserved in liquid nitrogen]. / Ocena klinicznej przydatnosci krwinek plytkowych kriokonserwowanych W temperaturze par azotu.

The hemostatic effectiveness of platelet concentrates cryopreserved in a vapor phase of liquid nitrogen were evaluated after transfusion of 14 concentrates to 6 patients. Transfusion of AB0 and Rh-compatible platelet concentrates elevated the number of circulated platelets in donors by about 24 G/L. The mean corrected count increment (C.I.) after 001 and 24 hours post transfusion was 14.694 and 7.735/microliters/m2/10(11) respectively. Decrease of haemorrhagic diathesis, and correction of bleeding time in all cases have been observed.

Cryopreservation of platelet concentrates using glycerol-glucose.

Two to five units of platelet concentrate were frozen together in single bags using glycerol-glucose as cryoprotective agents and a special freezing plate which produced a reproducible, rapid freezing rate when immersed in liquid nitrogen. After thawing there was no loss in platelets compared to prefreezing controls. Phase microscopic evaluation after thawing, however, demonstrated large numbers of severely damaged platelets and a significant decrease in morphology score. Total ATP levels fell to 37-52% of controls, and thawed platelets did not aggregate with adenosine diphosphate or collagen or undergo release of nucleotides following incubation with thrombin. In vivo recovery one hour after transfusion of autologous platelets administered to patients with leukemia was significantly inferior (p less than 0.025) to results achieved in the same patients with autologous platelets frozen with dimethylsulfoxide. These results indicate that significant damage occurs following freezing and thawing utilizing glycerol-glucose as cryoprotective agents for frozen platelets and that further investigation is required prior to their clinical use. Blood banks currently interested in platelet cryopreservation for clinical use should utilize dimethylsulfoxide as a cryoprotective agent.

Effect of DMSO and a freezing-thawing process on the 'ecto-ATPase' and AChE activities of human platelets.

The activity of two membrane-bound enzymes of human platelets subjected to DMSO and a freezing-thawing process were analysed. Following treatment of fresh platelets with DMSO (5-20%) quantitative differences of AChE and 'ecto-ATPase' activities were seen. After cryopreservation of platelets in 5% DMSO the enzymatic activities of AChE and Mg2+-ATPase were no different from those obtained for fresh platelets. The lack of any changes in the activities of the enzymes of frozen platelets subjected to a washing procedure to remove DMSO, indicates that the mechanism of the DMSO-induced effect is reversible and that freezing-thawing process had no additional detrimental effects.