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M Niri

Publications and source records attributed to M Niri.

5 recordsLinked to original sources
PubMed1989

An automated optoelectronic reticulocyte counter.

Microscopic reticulocyte counting is time consuming and imprecise. A new reticulocyte counter has been developed, and the authors evaluated its utility for laboratory use. The counter, R-1000 of Sysmex-TOA Medical Electronics Company, Kobe, Japan, is based on the principles of flow cytometry. Reticulocytes are detected as fluorescent cells stained with a basic dye, auramine O, under argon-laser light. The automated count had high correlation to the manual count (r = 0.941). Linearity and reproducibility were both high. About 60 specimens were tested in one hour. Not only the reticulocyte percentage and count but also the maturity of reticulocytes was found from the intensity of the fluorescence, whether high, moderate, or slight. Normal reference values were 0.007 +/- 0.0055 (0.70 +/- 0.55%) for the reticulocytes, (4.63 +/- 1.09) X 10(9)/L for the reticulocyte count, 2.3 +/- 1.9% for highly fluorescent cells, 18.7 +/- 5.1% for moderately fluorescent cells, and 78.8 +/- 6.6% for cells with slight fluorescence. In patients with suppressed bone marrow function, such as is caused by chemotherapy, the reticulocyte fraction and count were low, and cells with slight fluorescence increased. In patients in whom bone marrow function was stimulated, such as with hemolytic anemia, the reticulocyte percentage, reticulocyte count, and highly fluorescent cells were high. Patients with chronic renal failure being treated by hemodialysis had a similar reticulocyte pattern to that in hemolytic anemia except that the reticulocyte count was decreased. Results for elderly patients were not different from those of healthy young controls. Some patients with a normal reticulocyte count and percentage had numerous highly fluorescent cells, perhaps because of hemolytic anemia not yet identified. Automated reticulocyte counting provides reliable data, so such measurement should be useful for analysis of the kinetics of red blood cells and for the study of the pathogenesis of anemia.

Adult↗
PubMed1989

Inaccuracy and imprecision of reticulocyte counting.

Reticulocyte count is an essential clinical test to detect erythropoietic activity. The test has been done manually with the use of one of three dyes: new methylene blue, brilliant cresyl blue, and azure B. When reticulocyte counts with the different dyes were compared, correlation was good. When reticulocyte counts obtained by use of the dyes were compared with the count obtained by an automated counter, correlation was high. In a sampling study, the specimen prepared by a spinner method gave smaller variations than a wedge method. Intertechnologist bias was higher than inter-specimen or intra-specimen bias: The variation of the reticulocyte count was examined with from 200 to 2,000 cells; with 1,000 cells or more, variation was low. From these results, we concluded that more than 1,000 erythrocytes on one slide prepared by the spinner method should be analyzed. Clear standards for cell identification are also needed.

Blood Cell Count↗
PubMed1989

An automated reticulocyte counting method: preliminary observations.

We evaluated the counting of reticulocytes in the peripheral blood with a newly developed flow cytometer type of automated counter that performs a single test within 60 s. The volume of sample needed is 100 microliters and the cells are stained with auramine-O in the counter. The mean within-run reproducibility was 4.66% (CV, n = 50), and dilution of blood gave highly linear results with an r value of 0.996. Correlation was good between manual reticulocyte counts and those performed with the counter (r = 0.893). Samples with large numbers of leucocytes, erythrocytes, or platelets did not interfere with the automated reticulocyte counting, and provided accurate and precise data.

Autoanalysis↗