Sensitivity of the ultrasonic interferometry method (Echo-Cell) to changes of red cell aggregation: application to diabetes.
The sensitivity of the ultrasonic interferometry method (Echo-Cell) to changes in red blood cell (RBC) aggregation was investigated in comparison to the Regulest erythroaggregometry known as a reference method. In experiments where different concentrations of dextrans of 40 or 70 kD molecular weights were added to normal RBCs, the Echo-Cell was proved as sensitive as erythroaggregometry. A comparative study using RBC samples from normal and diabetic subjects showed that the Echo-Cell was much more sensitive when aggregation was measured in diluted than undiluted plasma. The sensitivity of Echo-Cell measurements in diluted plasma was similar to that of erythroaggregometry. Further analysis revealed that RBC aggregation was underestimated by Echo-Cell when measurements were made in undiluted plasma containing high fibrinogen levels, implying that in that case an elevated plasma viscosity might indirectly affect the sensitivity of the Echo-Cell. The low sensitivity of the Echo-Cell to detect an abnormal RBC aggregation when suspensions were prepared in undiluted plasma, is likely related to a relatively high shear stress exerted on RBC aggregates by the suspending medium. In conclusion, the sensitivity of the Echo-Cell to detect abnormal changes in RBC aggregation can be optimized by diluting the plasma.
Khodabandehlou
T
T
Unité de Recherches d'Hémorhéologie Clinique et de Microcirculation, Centre Hospitalier 58000 Nevers, France. urhr@club-internet.fr
Boynard
M
M
Guillet
R
R
Devehat
C Le
CL
D000328:Adult; D055592:Biophysical Phenomena; D001703:Biophysics; D001799:Blood Sedimentation; D003911:Dextrans / Q000494:pharmacology; D003924:Diabetes Mellitus, Type 2 / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D004867:Equipment Design; D004903:Erythrocyte Aggregation; D004912:Erythrocytes / Q000166:cytology*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D018056:Hemorheology; D006801:Humans; D007368:Interferometry; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014465:Ultrasonics; D014463:Ultrasonography
D003911:Dextrans; D005340:Fibrinogen