Monitoring of red blood cell aggregability in a flow-chamber by computerized image analysis

Photodynamic Treatment of Red Blood Cell Concentrates For Virus Inactivation Enhances Red Blood Cell Aggregation: Protection with Antioxidants

“…To learn about the effect of virucidal treatment on the strength of the intercellular interaction in the RBC aggregates, the aggregation was monitored under increasing shear stress. It has been previously found that normal RBC aggregates are dispersed at about 2 dyne/cm2 (16), a shear stress that is in the range normally reached in small blood vessels (18). Table 1 shows that following the virucidal treatment the aggregates are still considerably larger than normal even at 4 dyne/cm*.…”

“…RBC uggregubility. Aggregation was determined by CFA, described in detail elsewhere (16). In this system the RBC aggregation process in a narrow-gap flow chamber (30-40 Fm) is monitored under controllable flow rate by direct visualization under a microscope connected to a charge-coupled device camera, which transmits digitized images to a computer.…”

“…In this system the RBC aggregation process in a narrow-gap flow chamber (30-40 Fm) is monitored under controllable flow rate by direct visualization under a microscope connected to a charge-coupled device camera, which transmits digitized images to a computer. The RBC image analysis provides the distribution of aggregate size (number of cells per aggregate) and the median or average aggregate size, the shear stress required to disperse the aggregates (16) and an aggregate shape parameter that describes its deviation from the normal rouleau shape (17).…”

Aggregation of red blood cells in patients with Gaucher disease

“…Subsequent to this, two sets of samples were prepared for RBC aggregation testing: in one set, RBCs were suspended in centrifuged autologous plasma at a haematocrit of 5%; in the second set, RBCs were suspended in phosphate‐buffered saline pH 7·4, 1% bovine serum albumin (Sigma, St Louis, MO, USA) and 0·5% dextran 500 kDa (dextran‐500, Pharmacia Biotech, Uppsala, Sweden) at a haematocrit of 5%. Dextrans have been used extensively for studying RBC aggregation, and we have previously shown that a 0·5% solution of dextran‐500 induces the formation of RBC aggregates that are similar in size and shape to those formed in plasma (Chen et al , 1994). Thus, we used the dextran solution as a standard aggregating reference, which was not influenced by plasma proteins, and therefore enabled the assessment of intrinsic RBC aggregability.…”

Increased red blood cell adhesiveness/aggregation owing to fibrinogen elevation in hypercholesterolaemic patients and the rationale of fibrinogen‐lowering by LDL apheresis: authors’ reply

“…For this reason we recently compared the results obtained in our slide test with those determined by advanced cellflow properties analyses (CFA). In the CFA, red blood cell suspension is introduced into a narrow-gap flow chamber connected to a pump exerting laminar flow, and the shear stress level is monitored during the experiment via pressure transducers [1][2][3]. The dynamic organization of the erythrocytes in the flow chamber is visualized, recorded through a microscope and images analyzed by an image analyzer [4].Fifty-six sets of parameters were determined in healthy volunteers and obese individuals, as well as hypercholesterolaemic patients undergoing LDL apheresis [5,6].…”