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O Akerblom

Publications and source records attributed to O Akerblom.

At least 37 records · Page 2Linked to original sources
PubMed1983

Improvement of plasma quality as raw material for factor VIII:C concentrates. Storage of whole blood and plasma and interindividual plasma levels of fibrinopeptide A.

Blood collected into different anticoagulants was stored in small tubes at +4 degrees C for up to 26 h. Seven blood coagulation analyses were performed under standardized conditions. High yield and stability of factor VIII:C were found for ACD and CPD-adenine. No changes could be found in the other six parameters tested. Whole blood in blood bags could be stored for 2-4 h at +4 degrees C with maximal yield of F VIII:C, with blood stored overnight the recovery was 65%. In plasma F VIII:C was stable for at least 2 h at room temperature. F VIIIR:Ag and F VIIIR:RCoF were stable in both whole blood and plasma. No activation by plasmin as measured by B beta 15-42 could be demonstrated. The initial FPA levels, reflecting thrombin activation, in the donated blood differed individually and in some blood bags very high concentrations were found. The levels of FPA were not correlated to the time for collection of a bag of blood.

Anticoagulants↗
PubMed1983

Platelet concentrates stored at 22 degrees C need oxygen. The significance of plastics in platelet preservation.

Platelet concentrates prepared by platelet apheresis were stored in plastic blood bags with different gas permeability properties. Inadequate oxygen supply gave an insufficient adenosine triphosphate (ATP) regeneration and a compensatory increase in glycolysis and lactic acid production, giving a rapidly falling pH. At pH below 6.0 the glycolysis was inhibited, oxygen consumption ceased, and ATP dropped towards depletion. Adequate oxygen supply kept the lactic acid production low with small pH changes only, and allowed a sufficient ATP regeneration. The release of alpha-granular platelet Factor 4 (PF4) was almost total at pH below 6.0, while at intact metabolic function there was a slow release of PF4. Platelet preservation is enhanced by the use of blood bags with adequate gas exchange properties. In our study one polyvinyl chloride plastic (PVC) bag gave poor results, while another PVC bag and a polyolefin bag showed intact metabolism for 5 days and a moderate release of PF4.

Adenosine Triphosphate↗
PubMed1980

Adenine consumption in stored citrate-phosphate-dextrose-adenine blood.

Plasma adenine concentration was measured in five units of citrate-phosphate-dextrose-adenine (0.25 mmol/l adenine) whole blood during storage at +4 degrees C. The adenine levels decreased to 50% in 9-10 days and to approximately 15% in 3 weeks. In spite of this rapid consumption of adenine, the adenosine triphosphate levels were well maintained: almost 100% after 3 weeks and 60% after 6 weeks of storage.

Adenine↗
PubMed1980

Preservation of red blood cells with purines and nucleosides. I. Changes of ATP, 2,3-P2G and further parameters of metabolism in red cells stored as whole blood and as resuspension at 4 degrees C and 25 degrees C.

CPD blood with addition of adenine in 0.25 mM final concentration alone or in combination with guanosine and inosine each in 0.5 mM concentration and also with a higher adenine concentration--0.75 mM--was stored 6 weeks at 4 degrees C. In a second experiment red cell concentrates were prepared from CPD blood and resuspended in the same volume of a glucose-sucrose-citrate solution with the addition of adenine or guanine and both in combination with inosine. The resuspended cells were stored 7 days at 25 degrees C. Adenine and guanosine added simultaneously were most effective on the maintenance of ATP and P2G content. When guanosine was replaced by the same amount of inosine, no effect on P2G content was found in comparison with the addition of only adenine, however, the ATP content decreased more rapidly. The reason for this difference can be due to a different affinity of the IMP/GMP: pyrophosphate phosphoribosyltransferase to their substrates as well as regulation principles in the P2G bypass. The guanosine effect on red cell preservation consists in improved viability of red cells in vivo, increased nucleotide synthesis, increased formation of 2.3-P2G, delayed disc-spher transformation of red cells and decreased hemolysis. The most effective solution for red cell preservation should contain adenine, a pentose moiety like guanosine, and inorganic phosphate in a final concentrations in blood of 0.25 : 0.5 : 2 mM. The preparation of red cell concentrates from CPD-AG or CPD-A blood requires an elevation of glucose concentration in blood above 30 mM for storage periods up to 5--6 weeks.

2,3-Diphosphoglycerate↗
PubMed1975

A clinical evaluation of citrate-phosphate-dextrose-adenine blood.

(1) Blood was stored in polyvinyl-chloride bags containing citrate-phosphate-dextrose (CPD) with adenine in a final concentration of 0.25 mM. (2) Red cell ATP was well maintained (greater than 70% of original) for 4 weeks in whole blood as well as in red cell concentrate (PCV 85 plus or minus 2%). After 5 weeks the ATP level was about 70% in whole blood and about 40% in red cell concentrate. (3) Red cell 2,3-diphosphoglycerate (DPG) was about 60% of the original after 2 weeks and about 30% after 3 weeks of storage when stored both as whole blood and as red cell concentrate. (4) The red cell 24-hour post-transfusion viability was about 80% after 4 weeks of storage both as whole blood and as red cell concentrate. After 5 weeks of storage the 24-hour viability was 78.7 plus or minus 3.5% in whole blood and 76.5 plus or minus 6.7% in red cell concentrate. (5) 820 patients received 3,238 units of CPD-adenine blood, and 761 patients serving as controls received 2,807 units of acid-citrate-dextrose (ACD) blood. The frequency of transfusion reactions was 3.5% for patients receiving CPD-adenine blood and 4.1% for the control group. (6) The maximum storage time was set at 5 weeks for the CPD-adenine blood and 3 weeks for the ACD blood. The longer preservation time decreased out-dating by at least 50%.

ABO Blood-Group System↗
PubMed1975

Studies on citrate-phosphate-dextrose (CPD) blood supplemented with adenine.

The effect of varying adenine concentrations in citrate-phosphate-dextrose (CPD) blood was studied in an attempt to optimize the storage conditions for human erythrocytes with regard to posttransfusion viability and oxygen release function. The maintenance of diphosphoglycerate (DPG) was impaired by adenine supplementation; this effect was closely related to the adenine concentration. A 0.25 mM adenine concentration in CPD blood improved the adenosine triphosphate (ATP) levels and the posttransfusion viability markedly, without appreciably impairing the DPG maintenance. The results suggest that CPD solution supplemented with adenine to give a 0.25 mM concentration in the blood is a better preservative for human erythrocytes than the commonly used acid-citrate-dextrose (ACD), CPD, and ACD-adenine solutions with regard to posttransfusion viability and oxygen release function. Adenine addition to this low concentration is not expected to cause renal damage even after massive transfusion.

Adenine↗
PubMedDate not supplied

Purine metabolism of erythrocytes preserved in adenine, adenine-inosine, and adenine-guanosine supplemented media.

Four different media for erythrocyte preservation have been compared by studying 16 variables mainly describing the purine metabolism and glycolysis of the erythrocyte. The concentrations of the additives in the erythrocyte suspensions were as follows: adenine, 0.25 mmol/l; adenine, 0.75 mmol/l; adenine, 0.25 and inosine, 0.50 mmol/l; and adenine, 0.25 and guanosine, 0.50 mmol/l. Evaluated from the concentrations of glycerate 2,3-bisphosphate and purine nucleoside triphosphates, the medium with adenine-guanosine was superior to the others. In this medium with adenine-guanosine was superior to the others. In this medium the guanosine was rapidly split to guanine, which was slowly used for nucleotide synthesis or deaminated to xanthine. Differences between ATP and GTP in their reactivity with the two enzymes phosphofructose kinase seems to explain the beneficial effect of guanosine on preservation of erythrocytes.

Adenine↗