[SAG-S solution--a new medium for the resuspension of erythrocyte concentrates]. / SAG-S-Lösung--ein neues Medium zur Resuspension von Erythrozytenkonzentraten.

Concentrates of erythrocytes without buffy coat, re-suspended in a newly developed electrolyte-containing re-suspension solution (SAG-S) poor in saccharose (30 mmol/l) are in vitro compared with commercial CDS-AG RCC. In the equivalence of biochemical parameters complex-haematological indicators show a significantly improved maintenance of the cell integrity in the new preparation of blood constituents up to a storage time of 35 days. By means of an in-vitro-technique we calculated for these SAG-S-erythrocytes a post-transfusional survival rate of 74%. In contrast to this the in-vivo survival rate for 20-day-old CDS-AG-cells was only 65% In the practically equivalent content of erythrocytes the preparations differ as to their purity. The saccharose concentration of 200 mmol/l presented in the CDS-AG medium has, as it is made evident, a stabilizing effect on the leukocytes, i.e. it is retarding the time-dependent WBC-destruction. The results of the clinical test step III confirm a good tolerability of the SAG-S RCC. By lacking possibilities of the comparison of equivalent (produced under the same preparation and storage conditions) concentrates of erythrocytes the higher transfusion efficiency of the SAG-S concentrates of erythrocytes to be expected could not be verified.

[Erythrocyte volume distribution curves: a parameter for evaluating erythrocyte preparations]. / Erythrozytenvolumenverteilungskurven--Parameter zur Beurteilung erythrozytärer Zubereitungen.

The volume distribution of erythrocytes in ACD-AG blood and in human erythrocyte concentrations was investigated by means of computer-assisted techniques of hematological analysis. The storage-dependent distribution was described by the content of discrete class areas. Erythrocytes with a volume below 72 fl are only slightly capable of changing their volume. Their condition predisposes them to selection in the receiver's organism. Their percentage amount correlates with the share of cells ineffective of transfusion. The concentration of cells with a volume above 72 fl is discussed with ACD-AG blood (78% on the 42nd day), with CDS-AG erythrocyte concentrate (66% on the 20th day) and with SAG-M erythrocyte concentrate (74% on the 35th day) together with findings about the transfusional survival rate.

S A G--sucrose medium for red blood cell preservation.

A preservation solution for buffy coat-free red cell concentrates (RCC) was tested. It contained sodium chloride (150), glucose (50), adenine (1.25 mmol/l) and additionally sucrose (30 mmol/l). After 35 days of storage about 50% of the initial ATP were found. The 24-hours post-transfusion survival rate amounted to 76%. The hemolysis rate was 0.25% and only 2% of the red cell membrane were released as microvesicles when plastic bags were used for storage. Sucrose can be replaced by mannitol or sorbitol at the same concentration. Guanosine (0.4 mmol per 1 RCC) slightly but not significantly improved the maintenance of ATP and the morphology as well as the membrane stability.

Preservation of resuspended red cell concentrate. Red cell volume and hemolysis.

Sucrose in a concentration of 30 to 50 mmol/l preservation solution (10-20 mmol/l red cell concentrate (RCC) and 3-5 mmol per unit RCC) and an ionic strength of about 0.16 avoid changes of red cell volume during 6 weeks of storage. Increasing sucrose concentrations up to 80 mmol/l RCC decrease the hemolysis. But a sucrose concentration of only 10 mmol/l RCC causes an acceptable low hemolysis rate of 0.25% after 35 days of storage in PCV FENWAL plastic bags. Sucrose can be replaced by mannitol or sorbitol at the same final concentration. Changes in red cell metabolism and viability will not be expected.

[Leukocyte content of erythrocyte concentrates without buffy coat]. / Untersuchungen zum Leukozytengehalt in Erythrozytenkonzentraten ohne Buffy-Coat.

In the blood constituent preparation human erythrocyte concentrate--produced from ACD-AG-blood by single buffy coat separation--the leukocyte content was conductometrically determined on the automation for haematological analyses PHA-1/2. In the erythrocyte concentrate without buffy coat (age of the initial conserved blood 8 hours) we proved an average reduction of leukocytes of 41%. The registrable whole elimination of leukocytes correlates in direct proportion with the pre-storage time of the ACD-AG bloods. Investigations of the destruction of leukocytes in the ACD-AG-blood confirmed the dependence of the leukocyte destruction on the pre-storage time, i.e., the formation of cell fragments with a volume of 60 fl, which were not seized with the method used. The 40 per cent elimination must be regarded as real size of the leukocyte reduction by single buffy coat separation.

Agar plate tests of enhanced sensitivity for detecting biologically active products of staphylococcal filtrates.

Optimal conditions for detecting staphylokinase, phosphatase, protease, lipase, esterase, egg yolk factor, lysozyme, deoxyribonuclease, hyaluronidase, penicillinase, and alpha-, beta-, and delta-hemolysins in cell-free filtrates of selected strains of staphylococci by agar plate methods were established by studying the effect of factors such as buffer composition, pH, ionic strength, type of agar, nature and concentration of substrate, and certain metal ions. The final tests that evolved from this study are simple to perform, require only 6 mul of the sample per test, and are capable of detecting microgram and, in some cases, nanogram quantities of the product. The zones of reaction can also be quantitatively related to the amount of material present. The test may also be useful for the detection of extracellular products of other microorganisms.