Biomedical subjects

E Beutler

Publications and source records attributed to E Beutler.

At least 649 records · Page 36Linked to original sources

PubMedDate not supplied

Spectrin extractability in blood storage.

The extractability of spectrin from red blood cell membranes was measured both by dialysis against 1 mM EDTA for 44 hours and by incubation with 1 mM EDTA for 60 minutes. We confirmed that the extractability of spectrin is somewhat impaired when membranes are prepared from metabolically depleted erythrocytes, but the extent of impairment was considerably less than has been previously reported. Red blood cells which had been rendered nonviable by prolonged storage in citrate phosphate dextrose solution manifested normal spectrin extractability. We conclude that the loss of spectrin extractability is an insensitive manifestation of loss of red blood cell viability, and that it is not suitable for the prediction of loss of viability during red blood cell storage.

Blood Glucose↗

PubMedDate not supplied

In vivo viability of red blood cells stored in CPDA-2.

The marginal viability of erythrocytes stored for 35 days as red blood cell concentrates in citrate-phosphate-dextrose-adenine-one (CPDA-1) was attributed to inadequate nutrient support with adenine and glucose. In an effort to improve the viability of red blood cells following extended storage, a new CPD-adenine and 1.4 times more glucose than CPDA-1. The efficacy of CPDA-2 was evaluated in vivo by measurement of 24-hour postinfusion recovery of 51Cr-labeled erythrocytes which had been stored as whole blood or red blood cell concentrates for 5 to 8 weeks. All red blood cell concentrates, and the whole blood units stored for 35 and 42 days, were held at room temperature for 8 hours prior to processing and/or refrigeration. CPDA-2 yielded significantly higher 51Cr survivals than CPDA-1 and exceeded the accepted criterion for anticoagulant preservative efficacy of 70 percent postinfusion survival of red blood cells after storage for a period of 42 days. Preliminary data supports possible usage to 49 days. Plasma glucose and red blood cell ATP concentration were maintained better in CPDA-2 than in CPDA-1. When compared to historical controls for CPD and CPDA-1 the data suggest that red blood cells stored in CPDA-02 will have superior viability throughout the entire storage period. CPDA-2 is a candidate to replace CPDA-1 as the anticoagulant-preservative solution of choice for red blood cell concentrates.

Adenine↗

PubMedDate not supplied

Measurement of the viability of stored red cells by the single-isotope technique using 51Cr. Analysis of validity.

A single-isotope 51Cr method often is used to evaluate the viability of stored red cells. In this technique, the red cell mass is measured by back-extrapolation to time zero (t0) of the radioactivity of the blood between 5 and 20 minutes after infusion of the sample. If there is early destruction of stored cells, this method provides an overestimate of the red cell mass and, hence, of the viability of the stored cells. Freshly drawn red cells from normal donors were labeled with 99mTc, and cells from the same donor which had been stored in citrate-phosphate-dextrose-adenine-one (CPDA-1) for periods ranging from 7 to 49 days were labeled with 51Cr. A comparison of the "true red cell mass" as determined with 99mTc with the back-extrapolated red cell mass from stored 51Cr-labeled cells has made it possible to define the magnitude of error introduced by early loss of red cells. The overestimation of red cell mass and viability was diminished if only the 51Cr radioactivity between 5 and 15 minutes after infusion was used in back-extrapolating to t0. The degree of overestimation of red cell mass was greatest when the red cell viability had declined to very low levels. However, in the entire range of 10 to 80 percent viability, the overestimate of viability was usually less than 4 percent. The overestimate of viability proved to be quite similar for all samples and may be taken into account when using the single-isotope technique for measurement of red cell viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Glycolytic enzymes of stored granulocytes.

A marked reduction of granulocyte chemotactic function accompanies the storage of granulocyte concentrates. Since chemotaxis is energy dependent, we studied energy metabolism in stored neutrophils. We and others have reported that stored neutrophils have a defect in their energy metabolism. We found that defective adenosine triphosphate maintenance in stored neutrophils was occult in resting cells, but was unmasked by an energy-intensive stimulus, phagocytosis. In studies reported here, we sought to determine if defective adenosine triphosphate maintenance during granulocyte storage was related to altered glycolytic enzyme activity. We studied the activity of glycolytic enzymes in fresh and stored, resting and stimulated (opsonized zymosan) neutrophils. The following enzyme activities showed no major changes during storage, in resting or stimulated neutrophils: hexokinase, phosphofructokinase, aldolase, glucose phosphate isomerase, triose phosphate isomerase, glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase, phosphoglyceromutase, enolase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, glutathione reductase, and glutathione peroxidase. In contrast, pyruvate kinase activity consistently increased during storage. In 6 units, pyruvate kinase activity increased by 75 percent after 24 hours of storage at room temperature and by 198 percent after 48 hours. The storage-associated increase in pyruvate kinase activity was not inhibited by cycloheximide. Stimulation of neutrophils by phagocytosis of opsonized zymosan also produced striking increases in the pyruvate kinase activity of both fresh and stored cells. Additional studies indicated that the increases in pyruvate kinase activity observed during storage and after phagocytosis were associated with an increase in the availability of pyruvate kinase activity in the supernatant fraction of neutrophil sonicates. Total pyruvate kinase activity in sonicates of neutrophils was unchanged by storage or particle ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗

PubMedDate not supplied

Volume control of erythrocytes during storage. The role of mannitol.

When red cells are stored as suspensions in artificial preservative solutions such as those consisting of saline, adenine, and glucose, increased hemolysis of the red cells occurs in vitro, a phenomenon that is readily prevented by the addition of mannitol. The mechanism by which mannitol prevents hemolysis is unknown. The authors have examined the possibility that mannitol prevents hemolysis by prevention of osmotic swelling of red cells that might otherwise increase their volume beyond their critical hemolytic volume. Storage in artificial media does, indeed, result in swelling of the red cells, which is prevented by mannitol and is increased by the addition of nystatin, an agent that greatly increases the sodium-potassium permeability of the cells. Swelling and hemolysis are correlated at different concentrations of mannitol, but the correlation breaks down when the case of nystatin-treated cells is considered; even with marked swelling, there is relatively little hemolysis. Moreover, increasing the volume of the stored red cells acutely by osmotic means results in relatively little additional hemolysis. These findings make it appear unlikely that simple osmotic lysis is the cause of hemolysis in stored cells. Some other stabilizing effect of mannitol that may or may not be related to its osmotic effect must play a role.

Blood Preservation↗

PubMedDate not supplied

The effect of additives on red cell 2,3 diphosphoglycerate levels in CPDA preservatives.

Forty-two chemical substances, chosen because they might influence red cell metabolism, were screened for effect on red cell adenosine triphosphate and 2,3 diphosphoglycerate (2,3 DPG) levels during storage in CPD or CPDA-1 at 4 degrees C. Of these substances, six appeared on initial screening to increase 2,3 DPG levels during storage; on repeated examination, four compounds, i.e., oxalate, glyoxalate, ethyl oxaloacetate, and L-phenylalanyl-L-alanine, consistently increased 2,3 DPG levels during storage. It was shown that glyoxalate was converted rapidly to oxalate in blood, presumably through the lactate dehydrogenase reaction. Ethyl oxaloacetate is known to hydrolyze, giving rise to oxalate. Thus, the effect of both glyoxalate and ethyl oxaloacetate can be explained by the formation of oxalate, a compound already known to increase 2,3 DPG levels. The effect of L-phenylalanyl-L-alanine remains to be explained, but it may be hydrolyzed to L-alanine and L-phenylalanine, both of which are thought to have the capacity to increase red cell 2,3 DPG levels by inhibiting pyruvate kinase activity.

2,3-Diphosphoglycerate↗

PubMedDate not supplied