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Cytometric Methods (cytometric + methods)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

C-Kit receptor (CD117) expression on myeloblasts and white blood cell counts in acute myeloid leukemia

CYTOMETRY, Issue 1 2004
Jolanta Wo
Abstract Background The c-Kit receptor is considered to play a crucial role in hematopoiesis. Induction of mobilization of hematopoietic cells in the bone marrow requires cooperative signaling through c-Kit and c-Kit ligand pathway, and these interactions are important in the retention of stem cells within the bone marrow. Therefore, we analyzed c-Kit density on the leukemic myeloblasts of patients with acute myeloid leukemia (AML) in relation to white blood cell count (WBC) in the peripheral blood. Methods Bone marrow aspirates collected from patients with AML and bone marrow aspirates and leukapheresis products after granulocyte colony-stimulating factor blood mobilization from adult volunteers were studied. To determine the level of c-Kit receptor expression, we applied quantitative (relative fluorescence intensity and antibody binding per cell) cytometric methods. Results Our data showed negative correlation between the level of c-Kit expression intensity on myeloblasts and the number of leukocytes in blood of AML patients. The c-Kit receptor density on myeloblasts in patients with low WBC was significantly stronger than that on myeloblasts in patients with high WBC. In the latter patient group, the density c-Kit receptor on myeloblasts was similar to that on CD34+ cells in mobilized peripheral blood. Conclusions The obtained data suggest an involvement of c-Kit receptor in the regulation of leukemic myeloblasts egress to the peripheral blood. © 2004 Wiley-Liss, Inc. [source]

Clinical applications of laser scanning cytometry

CYTOMETRY, Issue 3 2002
Attila Tárnok
Abstract This study reviews existing and potential clinical applications of laser scanning cytometry (LSC) and outlines possible future developments. LSC provides a technology for solid phase cytometry. Fluorochrome-labeled specimens are immobilized on microscopic slides that are placed on a conventional epifluorescence microscope and analyzed by one or two lasers. Data comparable to flow cytometry are generated. In addition, the position of each event is recorded, a feature that allows relocalization and visualization of each measured event. The major advantage of LSC compared with other cytometric methods is the combination of two features: (a) the minimal clinical sample volume needed and (b) the connection of fluorescence data and morphological information for the measured event. Since the introduction of LSC, numerous methods have been established for the analysis of cells, cellular compartments, and tissues. Although most cytometric methods use only two or three colors, the characterization of specimens with up to five fluorochromes is possible. Most clinical applications have been designed to determine ploidy and immunophenotype; other applications include analyses of tissue biopsies and sections, fluorescence in situ hybridization, and the combination of vital and nonvital information on a single-cell basis. With the currently available assays, LSC has proven its wide spectrum of clinical applicability in slide-based cytometry and can be introduced as a standard technology in multiple clinical settings. Cytometry (Clin. Cytometry) 50:133,143, 2002. © 2002 Wiley-Liss, Inc. [source]

Respiratory burst activity of polymorphonuclear cells is dependent on the cell preparation technique

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2003
J. Zhao
Background: Controversial results have been reported regarding the effect of anaesthetics on superoxide anion production during the respiratory burst (RB) of polymorphonuclear cells (PMN). The differences could be caused by the cell preparation methods and the aim of this study was to compare two techniques. Methods: RB activity was measured in cell suspensions isolated with the single-step Ficoll procedure and in unfractionated whole blood. Two concentrations of propofol (therapeutic and 10-fold of this, 6 µg ml,1 or 60 µg ml,1) were investigated after cell preparation with both methods. RB was stimulated with Escherichia coli (E. coli), phorbol 12-myristate 13-acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) and measured by means of fluorescence intensity in a flow cytometer. Results: The percentage of PMNs in whole blood which generate superoxide anions in response to fMLP was significantly lower (2.5 ± 0.7%; mean ± SEM) than that in Ficoll isolated cell suspensions (15.1 ± 1.7%). Incubation with propofol led to a concentration-related decrease of RB activity in Ficoll separated PMNs after both PMA and fMLP stimulation. No significant effect of propofol was observed on the RB in PMA stimulated whole blood samples. Conclusion: The results suggest that the influence of cell preparation methods should be considered when the in vitro effects of anaesthetics on PMN functions are studied with flow cytometric methods. [source]

The measurement and importance of red cell survival

AMERICAN JOURNAL OF HEMATOLOGY, Issue 2 2009
Robert S. Franco
The measurement of red blood cell survival in the circulation has progressed from the original differential agglutination technique of Ashby to current isotopic and flow cytometric methods. While occasionally useful in the clinic, these methods find widespread use in a number of important research areas, including the evaluation of new red cell storage media in transfusion medicine and studies of the pathophysiology of sickle cell disease and diabetes. In this review, measurement techniques are placed in historical perspective and examined for relative merits and suitable application. Am. J. Hematol., 2009. © 2008 Wiley-Liss, Inc. [source]