Adaptation of Coenzyme Stimulation Assays for the Nutritional Assessment of Vitamins B1, B2 and B6 Using the Cobas Bio Centrifugal Analyser

Author(s):  
J N Mount ◽  
E Heduan ◽  
C Herd ◽  
R Jupp ◽  
E Kearney ◽  
...  

Adaptation of coenzyme stimulation assays for the nutritional assessment of thiamine, riboflavin and pyridoxine on the Cobas Bio centrifugal analyser are described. Whole blood was collected into acid-citrate dextrose, which preserves the erythrocytes, prior to assay for several days. Washed erythrocytes stored at −70°C and subsequently thawed, showed altered enzyme activities. The methods offer improved precision over existing procedures and take advantage of the high throughput capabilities of the instrumentation.

1980 ◽  
Vol 59 (3) ◽  
pp. 163-168 ◽  
Author(s):  
M. Brada ◽  
L. A. Robinson ◽  
A. J. Bellingham

1. As it has been suggested that the beneficial effect of methylprednisolone in shock is due to its effect on erythrocyte oxygen affinity, we studied its effect on incubated erythrocytes and on haemoglobin solution. 2. Incubation of fresh whole blood anticoagulated with acid/citrate/dextrose with methylprednisolone (7 mmol/l) produced a significant decrease in oxygen affinity, which was not seen with lower concentrations of methylprednisolone. When either acid/citrate/dextrose blood stored for 10 days or fresh heparinized blood was used, no significant increase in the partial pressure of oxygen at 50% haemoglobin saturation (P50) was demonstrated even with methylprednisolone at 7 mmol/l. At the highest concentration achieved in plasma with standard therapeutic doses (56 μmol/l) there was no increase in P50 under all the conditions studied. 3. Methylprednisolone reduced the oxygen affinity of haemoglobin in solution. The reduction in oxygen affinity was less than that produced by 2,3-diphosphoglycerate and more than that of either sodium succinate or sodium chloride. 4. From the results of this study we conclude that the effect observed in whole cells is probably due to a direct effect of methylprednisolone on haemoglobin. To produce a significant decrease of oxygen affinity of whole blood in vitro requires a plasma concentration of methylprednisolone above that obtained in plasma in vivo, with the currently used therapeutic doses.


2016 ◽  
Vol 29 (02) ◽  
pp. 115-124 ◽  
Author(s):  
Juan González ◽  
Catalina López ◽  
Jorge Carmona

SummaryObjectives: Our objectives were as follows: 1) to validate a protocol for producing rabbit platelet-rich plasma (PRP); 2) to determine the influence of two anticoagulants, sodium citrate and acid-citrate-dextrose solution A, and gender on cell count in PRP and growth factor concentration in pure platelet-rich gel supernatants; 3) to correlate the variables evaluated.Methods: Whole blood from 18 New Zealand rabbits (9 males and 9 females) was obtained with sodium citrate and acid- citrate-dextrose solution A for processing PRP fractions (A and B), which were evaluated for haematology. The PRP fractions were either activated with calcium gluconate or lysated with a detergent. The concentrations of transforming growth factor beta 1 and platelet-derived growth factor BB were assayed by ELISA.Results: The sodium citrate PRP-B had significantly higher counts of platelets in comparison to PRP-A and whole blood obtained with the same anticoagulant and the homologous acid-citrate-dextrose solution A PRP fraction. The sodium citrate PRP-A had a significantly higher count of leukocytes compared to the homologous acid-citrate-dextrose solution A fraction. All the PRP fractions had a significant leuko-reduction when compared to whole blood. The sodium citrate PRP-A fraction from female rabbits had significantly lower platelet counts and significantly higher leukocyte counts than the same acid-citrate-dextrose solution A fraction. Growth factor concentration was not affected by the type of anticoagulant or gender.Clinical significance: The type of anticoagulant and gender affected the cell counts in PRP, but they did not influence the growth factor concentration. More complete rabbit PRP studies should be performed before evaluating this type of substance in models of disease.


1989 ◽  
Vol 17 (5) ◽  
pp. 461-466 ◽  
Author(s):  
M. Rocchigiani ◽  
M. Pescaglini ◽  
S. Sestini ◽  
V. Micheli ◽  
C. Ricci

An increase in the density of erythrocytes was observed after storage of whole blood for 30 days at 4°C in either acid citrate – dextrose or citrate – phosphate – dextrose – adrenaline. Glucose- 6-phosphate dehydrogenase activity in unfractionated red blood cell lysates did not vary with the storage time. Enzyme activity in the lighter fraction separated by density gradient centrifugation was higher than that in heavier fractions. The decline in glucose-6-phosphate dehydrogenase activity with density was less marked after storage of whole blood for 30 days. It is suggested that density modifications are not related to the ageing of erythrocytes and additional mechanisms may be involved.


Blood ◽  
1974 ◽  
Vol 43 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Jeffrey McCullough ◽  
Sandra J. Carter ◽  
Paul G. Quie

Abstract Storage of granulocytes for transfusion has not been practical because it has been considered that granulocyte function in bank blood is retained for only a few hours after collection. In the present study, granulocyte function was evaluated using the bactericidal assay and the quantitative nitroblue tetrazolium (NBT) method. Granulocytes from whole blood collected into acid citrate dextrose (ACD), citrate phosphate dextrose (CPD), heparin, ion exchange, and sodium citrate anticoagulants showed no functional impairment after 24 hr of storage at 4°C. With further storage, all granulocytes showed a loss of NBT activity. However, after 48 and 72 hr, granulocytes from whole blood stored in ACD and CPD killed the expected number of bacteria in the bactericidal assay. Thus, when tested in vitro, granulocytes maintain normal function, at least during the first 24 hr after collection when stored in certain anticoagulants under standard blood bank conditions.


1988 ◽  
Vol 60 (02) ◽  
pp. 209-216 ◽  
Author(s):  
Chantal Lalau Keraly ◽  
Raelene L Kinlough-Rathbone ◽  
Marian A Packham ◽  
Hidenori Suzuki ◽  
J Fraser Mustard

SummaryConditions affecting the responses of human platelets to epinephrine were examined. In platelet-rich plasma prepared from blood anticoagulated with hirudin or PPACK (D-pheny- lalanyl-L-prolyl-L-arginine chloromethyl ketone), epinephrine did not cause shape change or aggregation. In a Tyrode-albumin- apyrase solution containing a concentration of Ca2+ in the physiological range, and fibrinogen, epinephrine in concentrations as high as 40 μM did not induce platelet shape change, caused either no primary aggregation or very slight primary aggregation, and did not induce thromboxane formation, release of dense granule contents, or secondary aggregation. In contrast, in citrated platelet-rich plasma, epinephrine induced two phases of aggregation. This is not attributable to the generation of traces of thrombin since the same effects were evident when blood was taken into a combined citrate-hirudin anticoagulant or a combined citrate-PPACK anticoagulant. In a modified Tyrode-albu- min-apyrase solution containing approximately 20 μM Ca2+, 1 mM Mg2+, and fibrinogen, epinephrine induced extensive aggregation after a lag phase, but no primary phase was evident; thromboxane formation and release of dense granule contents accompanied the aggregation response. These responses were also observed when PPACK was included with the acid-citrate- dextrose anticoagulant, and in the washing and resuspending fluids. In the presence of aspirin or the thromboxane receptor blocker BM 13.177 a few small aggregates were detected by particle counting and by scanning electron microscopy; with the latter inhibitor, the platelets in the aggregates retained their disc shape; secondary aggregation and the responses associated with it did not occur. Thus thromboxane A2 formation is not necessary for the formation of these small aggregates, but is required for extensive aggregation and release. As with other weak agonists, the close platelet-to-platelet contact in the low Ca2+ medium appears to be necessary for full secondary aggregation. Omission of fibrinogen from the low Ca2+ medium prevented both primary and secondary aggregation in response to epinephrine. An antibody (10E5) to the glycoprotein Ilb/IIIa complex was completely inhibitory in the presence of fibrinogen. Thus the response of human platelets to epinephrine is influenced by the concentration of Ca2+ and the presence of fibrinogen in the medium in which they are suspended.


1987 ◽  
Author(s):  
G Pfliegler ◽  
J Arnout ◽  
J Vermylen

The rapid and specific detection of fibrin monomers (fm) and fibrin degradation products (fdp) is of major importance in the laboratory diagnosis of disseminated intravascular coagulation, deep vein thrombosis or pulmonary embolism. Most methods in use are either time-consuming, needing special techniques, or insensitive and poorly specific. Some time ago, Watanabe and Tullis described a simple and rapid, semiquantitative test to detect fm and fdp in plasma, based on the finding that ristocetin in low concentrations (1.0-1.5 mg/ml) can specifically precipitate fm and fdp. To 0.4 ml ACD plasma, 0.1 ml ristocetin (2.5 mg/ml) is added and vortexed. The mixture is then incubated for 30 min at 20°C and centrifuged at 50xg for 5 min. The test is considered to be positive when fibrin-like strands or small or large pellets are observed on the bottom of the tube. More recently, Pfliegler et al. reported that ristomycin (AGGRISTIN), a structural analogue of ristocetin, can replace ristocetin in this test.Here we report on further results with the ristomycin (AGGRISTIN) precipitation test in 138 patients with various intravascular thrombotic events. The results of this test, performed on ACD plasma, were compared to the serum fdp values detected by immunoelectrophoresis (IEF) and by the haemagglutina-tion inhibition test (HIT). In all 30 cases with serum fdp above 30 ug/ml (HIT) or 28 pg/ml (IEF), the precipitation test was positive; at lower fdp concentrations, as detected by HIT or IEF, the test still was positive in 70 per cent of these thrombosis patients, suggesting a superior sensitivity. In 16 patients with elevated fibrinogen levels (but no evidence of thrombosis), the test was positive in only 3. No false positive results were detected in 16 healthy controls. Preliminary results show that the minor disadvantage of the test (blood collection on acid citrate dextrose) may readily be overcome by the in vitro adjustment of the pH of citrate plasma, commonly used for other haemostatic tests, to between 7.0 and 7.4.On the basis of our results we suggest that the AGGRISTIN (ristomycin) precipitation test is a simple, rapid and reliable method for the laboratory diagnosis of intravascular clotting.


2016 ◽  
Vol 42 (4) ◽  
pp. 349-355 ◽  
Author(s):  
Christopher J. Kirwan ◽  
Ross Hutchison ◽  
Sherif Ghabina ◽  
Stephanie Schwarze ◽  
Abigail Beane ◽  
...  

Background/Aims: Recent updates to the Nikkiso Aquarius continuous renal replacement therapy (CRRT) platform allowed us to develop a post-dilution protocol for regional citrate anticoagulation (RCA) using standard bicarbonate buffered, calcium containing replacement solution with acid citrate dextrose formula-A as a citrate source. Our objective was to demonstrate that the protocol was safe and effective. Methods: Prospective audit of consecutive patients receiving RCA for CRRT within intensive care unit, who were either contraindicated to heparin or had poor filter lifespan (<12 h for 2 consecutive filters) on heparin. Results: We present the first 29 patients who used 98 filters. After excluding ‘non-clot' filter loss, 50% had a duration of >27 h. Calcium supplementation was required for 30 (30%) filter circuits, in 17 of 29 (58%) patients. One patient discontinued the treatment due to metabolic alkalosis, but there were no adverse bleeding events. Conclusion: Post-dilution RCA system is effective and simple to use on the Aquarius platform and results in comparable filter life for patients relatively contraindicated to heparin.


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