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R B Dawson

Publications and source records attributed to R B Dawson.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Blood storage XXII. Improvement in red blood cell 2,3-DPG levels at six weeks by 20 mM PO4 in CPD-adenine-inosine.

Inorganic phosphate has been known to assist red blood cell maintenance of ATP and in the presence of inosine to assist in the maintenance of 2,3-DPG. High concentrations of phosphate, while helping ATP maintenance, were found to be deleterious to 2,3-DPG maintenance in CPD-adenine preservatives. However, in the presence of inosine, concentrations of phosphate as high as 10 mM were advantageous to 2,3-DPG maintenance. The present study extends the observations on ATP and 2,3-DPG maintenance in CPD-adenine-inosine preservatives from the previous 10 mM to 20 mM phosphate. A high phosphate (20 mM) effect has been seen as improved maintenance of 2,3-DPG levels during the fifth and sixth weeks of storage of whole blood at 4C. This supports the previously reported observation of improved maintenance of 2,3-DPG in a 10 mM phosphate preservative. This is ten times the 2 mM phosphate concentration in CPD-adenine. In the low phosphate preservative (2 mM), 2,3-DPG maintenance is less than that in all of the higher phosphate preservatives after the second week of storage. ATP concentrations in this experiment show good maintenance throughout six weeks of storage.

Adenine↗
PubMedDate not supplied

Blood storage XXIII: 2,3-DPG maintenance for six weeks in a CPD-adenine-inosine preservative with and without methylene blue.

In a pilot study the optimal concentration of inosine for 2,3-DPG maintenance in a CPD-adenine (0.25 mM) preservative was confirmed to be at lease 10 mM. In these experiments, 2,3-DPG maintenance was nearly normal for six weeks of storage in CPD-adenine-inosine (10 mM) preservative with or without methylene blue. The control preservative lacking inosine showed a statistically significant decrease in 2,3-DPG concentrations after the 3rd week. Finally, 2,3-DPG levels were significantly better maintained in CPD-adenine preservatives that contained 15 mM concentrations of inosine, whether methylene blue was present or not (10(-6)M), compared to CPD-adenine-inosine preservatives that contained 5 mM inosine, with or without methylene blue. The methylene blue effect, while it can be demonstrated in most experiments to help the red blood cell maintain 2,3-DPG during prolonged blood storage, is judges to be a slight value. However, inosine is of great value in maintaining 2,3-DPG for prolonged (five to six weeks) liquid storage.

Adenine↗
PubMedDate not supplied

Blood storage XXIV: red blood cell 2,3-DPG and ATP maintenance for six weeks in CPD-adenine with higher phosphate, pyruvate, and dihydroxyacetone.

The individual and collective effects of various phosphate, pyruvate and dihydroxyacetone concentrations on 2,3-DPG and ATP maintenance during blood storage with CPD-adenine (0.25 mM), were studied. Phosphate concentrations ranged from 2 to 100 mM. Low concentations were best for 2,3-DPG maintenance during the first three weeks, after which there was no difference. ATP concentrations were better maintained by the highest phosphate concentrations in the first week. After the second week the lower concentrations of phosphate were better. With pyruvate 40 and 60 mM were the best for 2,3-DPG levels through six weeks of storage. ATP concentrations were poorest with high pyruvate. Maintenance of 2,3-DPG was above half normal for six weeks of storage in the 60, 80 and 100 mM DHA preservatives. ATP concentrations were best maintained in the preservative lacking DHA. Combinations of phosphate, pyruvate and DHA in concentrations which had been found to be effective when used individually were studied. Best maintenance of 2,3-DPG (above half normal levels) for six weeks was afforded by pyruvate, phosphate and DHA, and by pyruvate and DHA. ATP maintenance was best afforded by CPD-adenine alone and CPD-adenine with pyruvate and phosphate. Pyruvate alone maintained ATP less well and the pyruvate-DHA was worst. Intermediate in maintenance of ATP was the preservative containing pyruvate, phosphate and DHA.

Adenine↗
PubMedDate not supplied

Hemoglobin function in stored blood. XIX. Inosine maintenance of 2,3-DPG for 35 days in a CPD-adenine preservative.

This study establishes that 10 mM inosine is a sufficient additive to maintain 2,3-DPG levels in blood for five weeks of storage in CPD-adenine. No previous experiments were done with CPD-adenine (0.25 mM) using a design which would give statistical proof of the optimal concentration of inosine needed for maintenance of normal hemoglobin function (2,3-DPG) for five weeks of blood bank storage.

Adenine↗
PubMedDate not supplied

Blood preservation XXVI, CPD-adenine packed cells: benefits of increasing the glucose.

In searching for the optimal glucose concentration, this lab has monitored ATP, 2,3-DPG, pH, and glucose levels of samples taken from full blood units stored for 6 weeks at 4 C. The blood was collected into CPD-adenine containing 100, 125, 150, 175, and 200 per cent of the glucose present in CPD. The units were stored as whole blood, soft packed (50 to 70% Hct), or hard packed units (80 to 95% Hct). ATP values in general did not decrease very greatly in whole blood units and only moderately in soft packed units. However, in hard packed units a steady progressive decrease in the ATP values was seen to begin at day 14. In these hard-packed units the only improvement with extra glucose was seen beginning at day 14 when ATP maintenance was better with 200 per cent glucose, but the improvement was not significant until day 42. However, at 35 days the ATP values for 200 and 175 per cent glucose were noticeably better than for the other preservatives. Therefore, it appears from this study that the glucose concentration in CPD-adenine for hard-packed cells should be at least 175 per cent of that in regularly formulated CPD. Also, there would appear to be an advantage of having 200 per cent glucose in those units of blood that may be stored beyond 35 days for emergency blood shortage times.

Acid-Base Equilibrium↗
PubMedDate not supplied

Blood preservation XXVII. Fructose and mannose maintain ATP and 2,3-DPG.

Mannose and fructose as well as glucose have been shown to be effective for maintaining ATP and thus viability of stored red blood cells. Normal 2,3-DPG levels are desirable in stored red blood cells to provide the needed oxygen transport upon transfusion. ATP levels in sotred concentrated red blood cells in the new preservative, CPD-adenine (citrate-phosphate-dextrose-adenine) become critically low in the 5th week. In this study two hexoses and two pentoses are compared with dextrose in their ability to maintain ATP and 2,3-DPG. ATP levels were best maintained by fructose, then dextrose and mannose. ATP levels had fallen to critically low levels by four weeks with ribose and xylose. Red blood cell 2,3-DPG concentrations were also maintained by hexoses, with mannose being best, dextrose and fructose being similar. When ribose was used in addition to dextrose in CPD-adenine, ATP maintenance was improved and under the same conditions xylose improved 2,3-DPG maintenance. Fructose and mannose may be as useful as dextrose in citrate-phosphate preservatives for maintaining ATP and 2,3-DPG levels. Also, ribose and xylose may help the maintenance of ATP and 2,3-DPG, respectively, in CPD-adenine.

Acid-Base Equilibrium↗
PubMedDate not supplied

The use of ion-exchange resins as a blood preservation system.

A system using ion-exchange resins for the storage of whole blood was investigated. Blood was collected into CPD, thoroughly mixed and then divided into equal amounts. To one half of the split units, four grams of phosphate charged Amberlite IR-45 resin were added, while no additions were made to the other split units. Both aliquots were stored at 4 C, adhering to routine blood banking standards. The blood stored with the resin for up to 28 days maintained high levels of 2,3-DPG and adequate levels of ATP. This new resin system has several advantages over the present blood preservation technology. There is initial increase in pH that promotes greater glucose utilization. Inorganic phosphate is provided to maintain both ATP and 2,3-DPG levels. The resin buffers the blood and maintains a narrower pH range for red blood cell enzyme activity. The resin is totally inert, completely filterable and has the ability to adsorb bacteria from the suspending solution.

Adenosine Triphosphate↗
PubMedDate not supplied

Blood preservation. XXVIII. Galactose and maltose maintain red blood cell 2,3-DPG and ATP.

Because there may be inadequate dextrose in the newly licensed CPD-adenine for five or six weeks storage of high hematocrit red blood cells, this laboratory has examined some alternate sugars for their ability to maintain red blood cell metabolism during storage. In the current study, dextrose and fructose were studied as model or prototype nutrients. A third six carbon monosacharide, galactose, three dissacharides, lactose, maltose, and sucrose were studied in the same experiment. Of these, fructose best maintained ATP and 2,3-DPG during the fourth to sixth week of whole blood storage at 4 C. Dextrose was next best during this time and was nearly equivalent to fructose in the first three weeks of storage. Galactose and maltose both maintained ATP and 2,3-DPG, but not nearly so well as did fructose and dextrose. Sucrose and lactose were associated with the most rapid deterioration of ATP and DPG levels and they failed to maintain the progressive fall in pH which is usually associated with continuing, useful metabolism.

Adenosine Triphosphate↗
PubMedDate not supplied

Blood preservation. XXIX. Pyruvate maintains normal red cell 2,3-DPG for six weeks of storage in CPD-adenine.

Pyruvate was placed in experimental CPD-adenine (0.25 mM) blood preservative mixtures in four concentrations ranging from 40 to 320 mM. In the 320 mM pyruvate preservative, 2,3-DPG levels were elevated above normal for six weeks of whole blood storage at 4 C. The lower pyruvate concentrations maintained elevated or normal 2,3-DPG levels for less time: four weeks with 160 mM, two weeks with 80 mM, and one week or less with 40 mM or the control. ATP values were best maintained in the control. The higher pyruvate concentrations resulted in the most rapid decreases at ATP. However, even the 320 mM pyruvate did not cause ATP to fall below 2 microM/gm of Hb. The higher pyruvate concentrations produced and maintained a higher pH during storage. On the other hand, 2,3-DPG levels increased with pyruvate during the first week of storage when the pH was decreasing rapidly. This could be the result of its oxidation of NADH to NAD. The high pyruvate concentration which maintained elevated 2,3-DPG levels throughout the six weeks might be simulating the effect reported in pyruvate kinase-deficient red blood cells, in which blockage of glycolysis at that step is preventing 2,3-DPG catabolism.

Adenine↗
PubMedDate not supplied

Blood preservation. XXXIV. DHA maintains 2,3-DPG and its adverse effect on ATP is reversed with extra phosphate.

We have found that the addition of 10 mM inorganic phosphate to DHA in CPD-adenine maintains ATP levels at normal or higher than normal values for six weeks of storage. 2,3-DPG values are slightly lowered by the extra phosphate, but are still maintained at approximately half normal for four weeks by the DHA. The addition of a higher phosphate concentration, 20 mM, to DHA produced lower levels of ATP and 2,3-DPG than those observed with 10 mM phosphate, although both levels were better than in the CPD-adenine control. pH values in this experiment were lowest in the three preservatives containing DHA, probably indicating increased lactate production due to metabolism of this triose sugar, in addition to dextrose present in CPD.

Adenine↗
PubMedDate not supplied

Blood preservation. XLIII. Studies on the ascorbate mechanisms of maintaining red cell 2,3-DPG.

Our previous experiments on the mechanisms of ascorbate's effect on the red blood cell failed to show an effect of iodoacetate (IA), a sulfydryl inhibitor. In this study, in contrast to the previous, iodoacetate (85 micromolar) was seen to prevent continued red blood cell metabolism. During the first weeks there was an absence of a continual fall in pH; ATP levels were depressed below half normal; and 2,3-DPG levels fell to very low values within the first week. ATP was best maintained in the control preservative and next best maintained, at adequate levels, with ascorbate, 5 mM, with and without glutathione, 5 mM. 2,3-DPG levels were well maintained with ascorbate and ascorbate with glutathione. Poor ATP maintenance and rapid decreases in 2,3-DPG were observed with iodoacetate, IA plus ascorbate, and IA plus ascorbate and glutathione.

Adenosine Triphosphate↗
PubMedDate not supplied

Blood preservation XLIV. 2,3-DPG maintenance by dehydroascorbate better than D-ascorbic acid.

A study was designed to compare the effects of D-ascorbate and dehydroascorbate on red blood cell metabolism during blood storage. Dehydroascorbate increased red blood cell concentrations of 2,3-DPG such that the levels are above normal for four weeks and normal at six weeks of storage. In contrast, there is a gradual decrease in 2,3-DPG levels with D-ascorbate such that the levels are approximately 80 per cent of normal after six weeks. ATP levels were adversely effected such that the worst levels were produced by 10 and 5 mM dehydroascorbate, with 10 mM having a more adversive effect than 5 mM. Intermediate levels of ATP were produced by D-ascorbate, with the 10 mM concentration. The control CPD-adenine preservative maintained near normal ATP levels for the entire six-week storage period. pH values were initially slightly lower with dehydroascorbate compared to the other preservatives early in storage, the difference being slightly over 0.1 pH units.

Ascorbic Acid↗
PubMedDate not supplied

Blood preservation 33. Phosphate enhancement of ribose maintenance of 2,3-DPG and ATP.

Blood storage in CPD-adenine supplemented with 25 mM inosine and 10 mM phosphate gave 2,3-DPG levels as high as 140 per cent of normal for six weeks of blood storage at 4 C. Lower but normal 2,3-DPG levels were maintained throughout six weeks with inosine or inosine plus ribose. Ribose alone provided marginally increased DPG maintenance over the control, but ribose with phosphate maintained 2,3-DPG levels above 70 per cent of normal for five weeks of storage and two weeks longer than the control preservative. ATP levels were maintained at normal or above for six weeks with phosphate plus ribose or inosine. 2,3-DPG maintenance has previously been shown to be impaired by phosphate, unless inosine is also present. The ribose and inosine effects on 2,3-DPG maintenance are not additive. Phosphate also has an enhancement effect on ATP maintenance in the presence of either ribose or inosine.

Adenine↗
PubMedDate not supplied

Blood preservation 35. Red cell 2,3-DPG and ATP maintained by DHA-ascorbate-phosphate.

DHA (dihydroxyacetone, 60 mM) with ascorbic acid (d-ascorbate, 10 mM) kept 2,3-DPG concentrations above normal for six weeks. Levels of 2,3-DPG were below normal after four weeks with DHA alone and after two weeks with DHA-ascorbate-phosphate. As in previous studies, high phosphate concentrations decreased 2,3-DPG maintenance. ATP maintenance was best achieved with the following (in order of performance): DHA-phosphate (20 mM); DHA-phosphate (10 mM); the control, CPD-adenine preservative; Phosphate 20 mM; and DHA. DHA with ascorbate provides normal 2,3-DPG for six weeks. The adverse effects of DHA and DHA with ascorbate on ATP levels are modified by 10 mM phosphate.

Adenine↗
PubMedDate not supplied

Blood preservation 42: improvement of ascorbate's ability to maintain 2,3-DPG with inosine.

Inosine and ascorbate have been shown to maintain normal 2,3-DPG levels during three to four weeks of blood storage. With the introduction of CPD-adenine, which allows five weeks of storage, the desire for 2,3-DPG maintenance may receive new emphasis. Red blood cell 2,3-DPG remained at normal or higher levels for six weeks whenever 10 or 15 mM inosine and 10 mM vitamin C (L-ascorbate) or D-ascorbate were present in the CPD-adenine preservative. Provision by inosine of a five-carbon sugar for 2,3-DPG synthesis, bypassing the rate-limiting phosphofructokinase reaction, may allow NADH oxidation by ascorbate to provide an increased supply of substrate for the Rappoport-Luebering shunt, thus affecting the net increase and maintenance of 2,3-DPG.

Ascorbic Acid↗
PubMedDate not supplied

Dihydroxyacetone, pyruvate, and phosphate effects on 2,3 DPG and ATP in citrate-phosphate-dextrose-adenine blood preservation.

Blood was stored with various combinations of 60 mM dihydroxyacetone (DHA), 80 mM pyruvate and 10 mM phosphate in citrate-phosphate-dextrose-adenine-one (CPDA-1) preservative for 42 days. During that time, DHA was found to have a beneficial effect on 2,3 diphosphoglycerate (2,3 DPG), although a deleterious effect on adenosine triphosphate (ATP). Preservatives containing pyruvate gave similar results. However, DHA and phosphate together in CPDA-1 improved both 2,3 DPG and ATP. The adverse effect on 2,3 DPG levels that phosphate normally shows was reversed by the addition of DHA. These results indicate that the addition of phosphate alone, rather than pyruvate, or pyruvate and phosphate, to DHA in CPDA-1 would be preferable to the presently licensed CPDA-1 preservative.

2,3-Diphosphoglycerate↗
PubMedDate not supplied

An anti-i biphasic hemolysin in chronic paroxysmal cold hemoglobinuria.

Paroxysmal cold hemoglobinuria (PCH) was diagnosed in an elderly patient with a history of chronic lymphocytic leukemia. In this case, the Donath-Landsteiner antibody demonstrated anti-i specificity rather than the more commonly reported anti-P specificity. This unusual case of a biphasic hemolysin with anti-i specificity emphasizes the importance of performing a Donath-Landsteiner test when presented with serological or clinical findings that are suggestive of PCH.

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