Subject(s)
Coronary Artery Bypass/adverse effects , Graft Occlusion, Vascular/metabolism , Protein C/pharmacokinetics , Adult , Aged , Biotransformation , Drug Resistance , Female , Graft Occlusion, Vascular/epidemiology , Graft Occlusion, Vascular/genetics , Humans , Incidence , Male , Middle Aged , PrevalenceABSTRACT
Thrombin generation, as evidenced by plasma fibrinopeptide A (FPA) concentrations, was studied during blood collection from donors taking oral contraceptives (OC). 450 ml blood were drawn into Fenwal PVC bags from 26 OC users and 28 nonusers. Blood samples for determination of FPA, beta-thromboglobulin (BTG), thrombotest (TT), prekallikrein (PKK), antithrombin-III (AT-III) and factor VIII procoagulant activity (FVIII:C) were drawn from the bags immediately after ending blood donation and following storage for 24 h at 4 degrees C. The FPA concentrations following donation were significantly higher in the OC than in the control group (p less than 0.05). The levels of PKK were also higher in blood obtained from OC users (p less than 0.001), as was the FVIII:C level, the latter difference, however, was not significant (p = 0.06). No cold-promoted activation of factor VII, as evidenced from TT, was detected following storage at 4 degrees C, neither was any change observed in the FPA, PKK and AT-III levels. The BTG concentrations increased significantly during storage, most pronounced in the control group (p less than 0.05). The decay of FVIII:C was similar in the two groups, averaging 24.7%. No correlation was observed between the FPA levels and the other parameters determined. We conclude that thrombin generation is more pronounced during routine blood collection from donors taking OC.
Subject(s)
Blood Specimen Collection , Contraceptives, Oral/pharmacology , Thrombin/biosynthesis , Adult , Antithrombin III/metabolism , Factor VIII/metabolism , Female , Fibrinopeptide A/metabolism , Humans , Prekallikrein/biosynthesis , beta-Thromboglobulin/metabolismABSTRACT
During incubation for 24 h at 37 degrees C, erythrocytes from patients with hereditary spherocytosis (HS) undergo a greater increase in osmotic fragility than do normal cells, and this procedure has been recommended for differentiating more clearly between patients with very mild HS and normal subjects. The greater effect of preincubation on erythrocytes from patients with HS was confirmed, but, except in cases demonstrating a markedly increased osmotic fragility before incubation, this effect was outweighed by a simultaneous loss of test precision. It therefore seems that preincubation does not significantly contribute to the capability of the osmotic fragility test to detect very mild forms of HS.
Subject(s)
Erythrocytes/physiology , Incubators , Spherocytosis, Hereditary/diagnosis , Adult , Aged , Body Temperature , Dose-Response Relationship, Drug , Female , Humans , Male , Middle Aged , Osmotic Fragility , Sodium Chloride/pharmacology , Spherocytosis, Hereditary/blood , Time FactorsABSTRACT
No effect of 3 mumol ouabain on the osmotic fragility of red blood cells in subjects suspected of being carriers of hereditary spherocytosis, as well as in patients with overt disease could be demonstrated. These results are in disagreement with a recent report. Some possible explanations for these discrepant results are discussed. It is concluded that ouabain probably adds little to the diagnostic capability of the osmotic fragility test.
