[Clinical usefulness of blood platelets cryopreserved in liquid nitrogen].

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.

Donors leukapheresis on Fenwal CS-3000.

Leukocytes were collected from 24 donors using Fenwal CS-3000 cell separator. Two different sedimentation agents in citric acid were used. After collection donors hematologic data were evaluated.

The influence of CS-3000 plateletapheresis on blood donors and on platelet concentrates.

Platelet concentrates were prepared from blood of donors by means of Fenwal CS-3000, or by double centrifugation method. Platelets from CS-3000 were cryopreserved with 5% DMSO for 2-4 weeks. After thawing and washing platelets were stored in room temperature for 6 hours.

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.

Craviten effect on the metabolism of stored platelets.

Craviten effect on platelets suspended in their own plasma was investigated by two methods of incubation with the drug: the fresh platelets were incubated for 18 h at 4 degrees C with Craviten added to plasma and platelets stored for 18 h at 4 degrees C without Craviten were incubated with Craviten at 37 degrees C for 1 h. For evaluation of the metabolic activity and function of the platelets, the levels of high-energy compounds ATP and ADP, the activity of hexokinase and pyruvate kinase and the amount of adenyl nucleotides released by the platelets after thrombin addition were measured, and the spontaneous aggregation of platelets and c-AMP were determined. The experiments demonstrated that Craviten prevented the fall of ATP level of the stored platelets, raised the activity of hexokinase and pyruvate kinase in the platelets, increased the amount of nucleotides released by the platelets in the release reaction.

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.

Predictive value of lymphocytotoxic test and platelet aggregometry for the effect of transfused platelet concentrates.

Sera of patients with thrombocytopenic diathesis before platelet transfusion were evaluated using donor's platelets in the aggregometry test the donor's lymphocytes in the lymphocytotoxicity test. In most cases the results of both tests were in agreement, although sometimes, despite strongly positive results of LCTT, the Agr was negative. Both tests showed a similar value for the prediction of the effectiveness of platelet concentrates: Agr in 80% and LCTT in 71% of cases.

Storage of platelet concentrates using ion exchange resin charged with dibasic phosphate.

Platelet concentrates were prepared at twice the normal concentration and stored at room temperature for 7 days in either standard bags (controls) or bags to which 1 or 2 g of Amberlite resin beads charged with dibasic phosphate had been added. The resin beads served as a buffer system by providing a "slow release" form of phosphate ions as well as by binding CO2 produced during platelet metabolism. Control platelets demonstrated rapid falls in pH, ATP content, morphology score, and thrombin-induced nucleotide release after 24 hr of storage with a fall in pH to less than 6.

[Effect of cytostatic agents on the metabolism and ultrastructure of blood platelets in man].

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.

Changes of adenine nucleotides content and release reaction of human blood platelets following gamma irradiation.

The aim of this work was to examine the effect of gamma irradiation on the energy metabolism and physiological functions of blood platelets. Blood platelets were irradiated with a 60Co-source in the range of 0.5--8.

[Storage of platete concentrates at +4 degrees C and +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.

[Effect of cytostatic drugs on the metabolism of incubated human blood platelets].

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.

[Use of hydroxyethyl starch as a cryoprotective medium during platelet storage at low temperatures].

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.

[Storage of human bone marrow at - 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.