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Biomedical subjects

O Akerblom

Publications and source records attributed to O Akerblom.

13 recordsLinked to original sources
PubMed1992

Blood component processing technique and plasma quality.

To maintain a closed system during the preparation of blood components, including the removal of buffy coat, many centers use a quadruple blood bag additive solution system which in this study has been reduced to a cheaper triple bag system. The buffy coat and plasma were after centrifugation transferred to the first satellite bag and, after a second spin, the plasma separated from the buffy coat was transferred to the second satellite bag and stored for a fortnight at 4 degrees C. This resulted in a statistically significant increase in platelet factor 4 and elastase activity levels. No significant changes were found in the levels of C1-esterase inhibitor and kallikrein inhibiting activity, thrombin-antithrombin complexes, soluble fibrin, fibrinopeptide A and spontaneous proteolytic activity. The changes observed must be regarded as clinically insignificant. The platelet count is low enough to meet the requirements for platelet poor plasma. Using this blood component separation technique, one can reduce the CPD/additive solution 4-pack blood bag system to a less expensive 3-pack blood bag system.

Blood Banks↗
PubMed1992

Freezing technique and quality of fresh-frozen plasma.

Cell-poor plasma was prepared by apheresis from 10 donors. From each donor, an amount of 200 ml was frozen rapidly to -40 degrees C in standard blood bags, and a further 200 ml was frozen slowly to -20 degrees C. Before freezing and after thawing, plasma samples were collected and frozen to -70 degrees C pending analysis. Coagulation factor VIII activity was reduced to 90% by rapid freezing and to 80% by slow freezing. Factor V was not influenced by rapid freezing, but slow freezing reduced the levels to 92% of the pre-freezing levels. In some of the plasma bags a slight increase in fibrinopeptide A occurred. However, soluble fibrin, thrombin-antithrombin complexes and spontaneous proteolytic activity were not altered by freezing. The beta-thromboglobulin increased slightly with slow freezing. Moreover, in a separate experiment, evaluating the possible effects of refreezing plasma samples, an increase in beta-thromboglobulin was also recorded, while the levels of factors VIII and V and von Willebrand factor were not affected. The changes in some variables, which were recorded in the cell-poor plasma, frozen soon after the blood donation at a slow freezing rate, must be regarded as insignificant in most clinical situations.

Antithrombin III↗
PubMed1992

Allo-immunization during pregnancy. Clinical results from 1983 to 1989 in a Scandinavian university hospital.

From 1983 to 1989, 147,068 pregnancies were analyzed for allo-immunization against erythrocyte antigens. Approximately half of the cases were due to immunization against factor D and the others were due to allo-immunization against other antigens (K, c, E, etc.). In 61 cases exchange transfusion of the newborn was needed and in 115 cases diagnostic amniocentesis was done during pregnancy. Intrauterine transfusions were performed in 10 cases. Fetal and neonatal mortality was 4% in these moderate to severe cases, all due to immunization against D. Immunization against D was due to failure to give immunoglobulin anti-D in about 2/3 of the cases. Systematic prophylactic treatment with anti-D during pregnancy would probably not be cost-effective in this population.

Amniocentesis↗
PubMed1991

A study of the effect of ABO incompatible plasma in platelet concentrates transfused to bone marrow transplant recipients.

Bone marrow transplant recipients at Huddinge Hospital have routinely received single-donor platelet concentrates (PC) from blood group O donors. These PC contain approximately 350 ml plasma, which is incompatible with patients of group A, B and AB. In 27 patients transplanted with an ABO-identical bone marrow, serological investigations have been performed every week after transplantation (median 6 weeks, range 3-14). Nine of 11 recipients with blood group A developed a positive direct antiglobulin test (DAT) after PC transfusions, while none of 15 patients of blood group O developed a positive DAT. Anti-A could be eluted in DAT-positive cases. In no case was there any clinical sign of hemolysis. Nor did recipients of groups A, B or AB (n = 34) require more red blood cells or PC transfusions compared to recipients of group O (n = 47).

ABO Blood-Group System↗
PubMed1990

The effect of different agitation modes on platelet metabolism, thromboxane formation, and alpha-granular release during platelet storage.

Platelet concentrates (PCs), prepared by plateletpheresis, were stored in aliquots in polyvinylchloride blood bags for 5 days at 22 degrees C under rapid, slow, or no agitation. Nonagitated PCs were also stored in a 98-percent oxygen atmosphere. In nonagitated PCs, pO2, lactate production, and platelet factor 4 (PF 4) concentration increased, whereas the ATP level and pH dropped rapidly. These changes were somewhat minimized in nonagitated PCs stored in oxygen. There was no significant difference between the two agitated groups. The increase in PF 4 correlated inversely to the decrease in ATP: r = -0.91, p less than 0.001, n = 24. The formation of thromboxane B2 (TxB2) after stimulation with arachidonic acid or collagen was significantly higher in slowly agitated PCs on Day 5 than on Day 0 (p less than 0.01). Nonagitated PCs produced lower levels of TxB2 (collagen stimulation) on Day 5 (p less than 0.05). In unstimulated PCs, the levels of TxB2 and ATP were inversely correlated on Day 5 (r = -0.70, p less than 0.001, n = 20). In vivo survival was performed after 72 hours of storage; mean survival (+/- SD) was 6.5 (+/- 0.3) days for nonagitated oxygenated PCs and 6.8 (+/- 0.7) days for agitated PCs. In nonagitated PCs, anaerobic metabolism increased, although oxygen diffusion through the container wall was sufficient. Agitation seems to facilitate the diffusion of oxygen through the storage medium. Nonagitated PCs were stored safely for 24 hours; this period can be extended to at least 72 hours when aerobic metabolism is maintained.

Blood Cells↗
PubMed1990

The platelet storage capability of different plastic containers.

Platelet concentrates (PC), prepared by platelet apheresis, were stored in four different types of blood bags. One of the bags, manufactured with a thinner PVC film than previously, was tested in three different bag volumes. From 25 donors a total number of 99 PC were prepared. Platelet numbers varied from 20 to 140 X 10(9) platelets per bag. The cell count, pH, pO2, pCO2 and lactate were determined initially and on days 1, 3 and 5 of storage. In a separate test, the oxygen diffusion capacity of the bags was determined by oxidation of sodium sulfite in the presence of cobaltous chloride. The oxygen diffusion capacity found was 16 (PL 732, 300 ml), 13.5 (Teruflexa 800 ml), 11.5 (PL 1240, 400 ml), 10.6 (Teruflexa 600 ml), 9 (Teruflexa 400 ml) and 4 (PL 146, 300 ml) mumol O2/h, respectively. For each bag type, the minimum and maximum platelet number stored with maintained pH levels (6.9-7.4) was defined. The maximum platelet number stored with maintained aerobic metabolism, correlated to the oxygen diffusion capacity of the bag, r = 0.998, p less than 0.001, n = 6; thus the maximum platelet number successfully stored for 5 days in each container can be predicted by determination of the oxygen diffusion capacity. In PC with a low platelet yield, pH values above 7.4 were observed after 1 and 3 days. When the results are compared with platelet yield data from routine blood banking, the optimal bags for platelet storage can be chosen. These conclusions must be further investigated in studies in vivo.

Blood Platelets↗
PubMed1990

[Blood component therapy with additives].

Since 1988, 96% of all blood donations in Sweden are given in a multiple blood bag system using a SAGMAN-System. This system has many advantages over conventional blood bags without additive solution. We routinely eliminate 50-80% of the leucocytes and more than 80% of the platelets by separation of buffy-coat from red cells using such a system. We have compared the preparation results of a SAGMAN-System with a similar system containing top and bottom outlets (BAT) using 2 different semiautomatic separation systems. With these new bag systems and separation devices we received similar results. However by optimizing the procedure it should be possible to obtain a higher reduction of leucocytes and platelets at comparable red cell yield using the BAT-System.

Blood Component Removal↗
PubMed1986

Screening of factor VIII:C levels in blood donors.

A new chromogenic peptide substrate method, modified for assay with semi-micro tubes, Cobas Bio centrifugal analyser and microplates, was used for screening of F VIII:C in blood donors. The precision of the assays is high and the costs are reasonable. The assay with microplates is especially suitable for selection of donors for a plasma programme and for quality control in blood banks.

Blood Donors↗
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↗