A new four-color flow cytometric assay to detect apoptosis in lymphocyte subsets of cultured peripheral blood cells.

Background: Human peripheral blood lymphocytes kept in culture after isolation die by an apoptotic process. Detection of apoptosis with labeled Annexin V to demonstrate loss of plasma membrane asymmetry is sensitive, specific, and easy using flow cytometry. This is true in lymphoblastic cell lines when combining Annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI).

S-phase cells of the lymphoplasmocytic compartment in hyperdiploid multiple myeloma are diploid cells.

In vivo S-phase cell labeling with iododexoyuridine (IdUrd) was performed in six multiple myeloma (MM) patients. Myeloma cells from four patients were hyperploid. In three out of four patients, DNA/IdUrd flow cytometry revealed that most of the labeled cells, which had divided during the period, elapsed between flash labeling and sampling, had returned to the diploid G0/G1 compartment and not to the hyperdiploid peak.

Determination of the mean normal prothrombin time for assessment of international normalized ratios. Usefulness of lyophilized plasma.

To report a Prothrombin Time (PT) as International Normalized Ratio in controlling oral anticoagulant therapy, the Mean Normal PT (MNPT) is required. To correct for methodological differences in performing the PT test, each laboratory should determine its own MNPT for each batch of reagent using fresh blood samples from a large number of normal individuals. This would be a laborious procedure.

A Multi-centre study to evaluate method dependency of the international sensitivity index of bovine thromboplastin.

In The Netherlands, a particular coagulometer method for prothrombin time (PT) determination with reduced sample and reagent volumes is used by 62% of the laboratories controlling oral anticoagulant therapy. This "micro-method" has been calibrated against the manual tilt-tube technique for PT determination by six Dutch laboratories. Each laboratory tested 20 fresh normal blood samples and 60 fresh patient blood samples using both methods with the same batch of bovine thromboplastin reagent, according to a detailed protocol.