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Biomedical subjects

A D Knapp

Publications and source records attributed to A D Knapp.

6 recordsLinked to original sources
PubMed2001

The role of electrolytes and pH in RBC ASs.

BACKGROUND: Experimental additive solutions (EASs) containing saline, adenine, glucose, mannitol and disodium phosphate can support RBCs for 9 or 10 weeks if used in 200- or 300-mL volumes. The effects of variations in the electrolyte composition and volume of EASs were explored. STUDY DESIGN AND METHODS: In three four-arm studies, 24 RBC units were pooled in groups of 4 and realiquoted as test units to ensure that all donors were equally represented in each study arm. In Study 1, units were stored for 11 weeks in EAS containing 0, 10, 20, or 30 mmol per L of sodium bicarbonate. In Study 2, units were stored for 9 weeks in EAS containing 26, 50, 100, or 150 mmol per L of sodium chloride. In Study 3, units were stored in 100 or 200 mL of AS-3 or EAS-61. RBC ATP concentrations and hemolysis were measured weekly. RESULTS: Increasing the sodium bicarbonate content of EASs increased the pH throughout storage and increased RBC ATP concentrations in the later phases of storage, but it had no effect on hemolysis. Increased sodium chloride content of EASs led to lower RBC ATP concentrations and increased hemolysis. In EAS-61, RBC ATP concentrations were increased throughout storage, and hemolysis was lower than that of RBCs stored in AS-3. CONCLUSION: RBC ATP synthesis is highly dependent on the pH of the AS. Hemolysis is affected by the salt content and volume of the AS.

Adenosine Triphosphate↗
PubMed2001

RBC storage for 11 weeks.

BACKGROUND: Increasing the length of RBC storage can increase both RBC availability and quality. This work addresses 11-week RBC storage in experimental ASs (EASs). STUDY DESIGN AND METHODS: Three studies were performed. In the first, 24-hour in vivo recovery of (51)Cr-labeled autologous RBCs was measured in nine volunteers after storage of their RBCs for 11 weeks in EAS 67. In the second study, 4 units of blood were divided and stored in aliquots with an EAS containing 0, 15, 30, or 45 mmol per L of mannitol; then hemolysis, RBC morphology, and microvesicle protein were measured. In the third study, 6 full units were stored for 12 weeks in the EAS containing 30 mmol per L of mannitol, with weekly sampling for morphologic and biochemical measures of RBC quality. RESULTS: RBCs stored for 11 weeks in EAS-67 had a mean 24-hour in vivo recovery of 79 +/- 5 percent, but the hemolysis was 1.35 +/- 0.68 percent. Increasing mannitol content of the EAS reduced hemolysis but increased microvesiculation. EAS-76, with 30 mmol per L of mannitol allowed 11-week storage with 0.48 +/- 0.10 percent hemolysis at 11 weeks and 0.62 +/- 0.14 percent hemolysis at 12 weeks. CONCLUSION: It is possible to store RBCs for 11 weeks in EAS with greater than 75 percent recovery and less than 1 percent hemolysis.

Adult↗
PubMed2000

The effects of phosphate, pH, and AS volume on RBCs stored in saline-adenine-glucose-mannitol solutions.

BACKGROUND: RBC ATP concentrations are the most important correlate of RBC viability. Tests were performed to determine whether increased AS volume, pH, and phosphate content increased stored RBC ATP concentrations. STUDY DESIGN AND METHODS: In three studies, packed RBCs were pooled in groups of 3 or 4 units and realiquoted as combined units to reduce intradonor differences. Pooled units were stored in the licensed ASs, AS-1 or AS-5, which contain saline, adenine, glucose, and mannitol (SAGM), or in experimental ASs (EASs) containing SAGM and disodium phosphate. Ten pools were stored in AS-1 at RBC concentrations equivalent to 100, 200, or 300 mL of AS. Six pools were stored in 100, 200, 300, or 400 mL volumes of EAS-61. Ten pools were stored in 100 mL of AS-5, 200 mL of EAS-61, or 300 mL of EAS-64. RBC ATP concentration and other measures of RBC metabolism and function were measured weekly. RESULTS: RBC ATP concentrations decreased sooner with storage in increasing volumes of AS-1. In EAS-61 and EAS-64, RBC ATP concentrations initially increased and stayed elevated longer with increasing AS volume. CONCLUSIONS: The addition of disodium phosphate to SAGM AS increases the RBC ATP concentrations. Reducing storage Hct appears to have a separate beneficial effect in reducing hemolysis.

Adenine↗
PubMed2000

Successful storage of RBCs for 9 weeks in a new additive solution.

BACKGROUND: This study explored the effect of storing packed RBCs suspended in 200 mL of an alkaline, hypotonic, experimental additive solution (EAS 61). STUDY DESIGN AND METHODS: Packed RBC units prepared from RBCs collected from healthy donors in CPD were stored for 8 (n = 10) and 9 (n = 10) weeks under blood bank conditions after the addition of 200 mL of EAS 61 (adenine, 2 mM:; dextrose, 110 mM:; mannitol, 55 mM:; NaCl, 26 mM:; Na(2)HPO(4), 12 mM:). Standard methods were used for in vitro assays. The 24-hour in vivo autologous recoveries were measured with (51)Cr. RESULTS: Mean +/- SD recoveries at 8 and 9 weeks were 81 +/- 7 and 77 +/- 7 percent. After 9 weeks, the ATP of the RBCs was 81 percent of the initial value, hemolysis was 0.35 percent, supernatant potassium was 46 mEq per L, and the morphologic index was 94.1. CONCLUSION: Packed RBCs suspended in 200 mL of EAS 61 can be stored satisfactorily for 9 weeks. Longer RBC storage should reduce outdating, increase availability of transfusions in remote locations, and improve the efficiency of autologous donor programs.

Adult↗
PubMed2000

Successful storage of RBCs for 10 weeks in a new additive solution.

BACKGROUND: The effect of storing packed RBCs suspended in 300 mL of an alkaline, experimental additive solution (EAS 64) was explored. STUDY DESIGN AND METHODS: RBC units prepared from blood collected from healthy donors into CPD were WBC reduced and stored for 10 weeks under blood bank conditions after the addition of 300 mL of EAS 64 (adenine, 2 mM:; dextrose, 50 mM:; mannitol, 20 mM:; NaCl, 75 mM:; Na(2)HPO(4), 9 mM:). For comparison, non-WBC-reduced units from the same donors were stored in a different additive solution (AS-1, Baxter Healthcare) for 6 weeks. Standard methods were used for the in vitro assays. The 24-hour in vivo recoveries were measured by using (51)Cr- and (99m)Tc-labeled RBCs. RESULTS: Mean recovery in the EAS 64 units after 10 weeks was 84 +/- 8 percent, the same as in the AS-1 units stored for 6 weeks. For EAS 64 and AS-1 units, respectively, the ATP of the RBCs was 85 percent and 64 percent of the initial value, hemolysis was 0.43 percent and 0.63 percent, supernatant potassium was 24 mEq per L and 44 mEq per L, and the morphologic index was 98 and 71. CONCLUSION: RBCs suspended in 300 mL of EAS 64 can be stored satisfactorily for 10 weeks. Longer RBC storage should reduce outdating, increase availability of transfusions in remote locations, and improve the efficiency of autologous donor programs.

Adenosine Triphosphate↗