Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-3-5
pubmed:abstractText
Syllectometry is a measuring method that is commonly used to assess red blood cell (RBC) aggregability. In syllectometry, light is incident on a layer of whole blood initially exposed to shear flow. The backscattered light is measured after abruptly stopping the driving mechanism. The resultant time-dependent intensity plot is called the syllectogram. Parameters that quantify RBC aggregability are obtained by analyzing the syllectogram. As we will show in this paper, the upstroke in the initial part of the syllectogram contains the information for measurement of RBC-shape recovery in whole blood as well. To estimate RBC-shape recovery, we extended the existing two-exponential mathematical representation of the syllectogram by a third exponent that describes the upstroke. To investigate the feasibility of RBC-shape recovery measurement from the upstroke, we derived an analytical model of the flow decay that follows after abruptly stopping the driving mechanism. The model reveals that for large gaps the flow decay may interfere with the true RBC-shape recovery process. These theoretical findings were confirmed by velocity measurements in a Couette-type aggregometer. Syllectograms obtained using large gaps differ in many respects from those obtained using small gaps. As predicted by our model large gaps show a prolonged apparent shape-recovery time-constant. Moreover, a delayed intensity peak, a reduced upstroke of the intensity peak and a considerable increase of the half-life parameter are observed. The aggregation indices for large gaps are lower than for small gaps. This paper yields a better understanding of the velocity and shear-rate decay following upon abruptly stopping the driving mechanism. A better mathematical representation of the syllectogram and recommendations for a maximum gap width enables both RBC-shape recovery and aggregation measurements in whole blood using syllectometry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0018-9294
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
97-106
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed-meshheading:12617529-Blood Flow Velocity, pubmed-meshheading:12617529-Blood Viscosity, pubmed-meshheading:12617529-Elasticity, pubmed-meshheading:12617529-Equipment Failure Analysis, pubmed-meshheading:12617529-Erythrocyte Aggregation, pubmed-meshheading:12617529-Erythrocyte Deformability, pubmed-meshheading:12617529-Erythrocytes, pubmed-meshheading:12617529-Hemorheology, pubmed-meshheading:12617529-Humans, pubmed-meshheading:12617529-Laser-Doppler Flowmetry, pubmed-meshheading:12617529-Models, Cardiovascular, pubmed-meshheading:12617529-Nephelometry and Turbidimetry, pubmed-meshheading:12617529-Quality Control, pubmed-meshheading:12617529-Reproducibility of Results, pubmed-meshheading:12617529-Scattering, Radiation, pubmed-meshheading:12617529-Sensitivity and Specificity, pubmed-meshheading:12617529-Shear Strength, pubmed-meshheading:12617529-Stress, Mechanical
pubmed:year
2003
pubmed:articleTitle
Syllectometry: the effect of aggregometer geometry in the assessment of red blood cell shape recovery and aggregation.
pubmed:affiliation
Department of Medical Technological Development, Academic Medical Center. University of Amsterdam, P.O. Box 22700, 1 100 DE Amsterdam, The Netherlands. j.g.dobbe@amc.uva.nl
pubmed:publicationType
Journal Article, Comparative Study, Evaluation Studies, Validation Studies