Laboratory evaluation of the Miles H.3 automated reticulocyte counter. A comparative study with manual reference method and Sysmex R-1000.

OBJECTIVE: To evaluate the performance of the new commercial Miles H.3 RTX analyzer in counting reticulocytes. METHODS AND PATIENTS: The results from the counter were compared to those obtained from microscopic methods, following the National Committee for Clinical Laboratory Standards H44-P guidelines, and to the results from the Sysmex R-1000 counter. In total, 279 samples were analyzed in duplicate with each of the three methods. One hundred thirty-three samples were from healthy subjects, while 146 were from patients with various pathologies, 10 of whom presented with posttherapeutic aplasia of the bone marrow and 9 with iron-deficiency anemia. RESULTS: The reference intervals for the normal controls are different for each of the three methods (manual: 0.35-2.35%, 16 to 116 x 10(9)/L; Miles H.3: 0.65-2.30%, 35.1 to 112.0 x 10(9)/L; Sysmex R-1000: 0.6-1.85%, 28.0 to 85.0 x 10(9)/L). The overall imprecision was lower for the instruments than for the microscopic method (Miles H.3: coefficient of variation, 11.6%; R-1000: coefficient of variation, 4.2%; microscopic method: coefficient of variation, 24.2%). The Miles H.3 shows a good correlation with the other methods, yet it overestimated the low values with respect to both the microscopic method (intercept, 0.55; slope, 0.70) and the R-1000 (intercept, 0.44; slope, 0.78). This became particularly pronounced in patients with marrow aplasia. CONCLUSIONS: Miles H.3 can produce results with an acceptable degree of accuracy. The agreement with the dedicated fluorescence-based flow cytometer R-1000 at normal and high concentrations is also good. The possibility of providing reticulocyte indices as well as erythrocyte indices (mean volume, mean hemoglobin content, mean hemoglobin concentration) and the relative dispersion indices could be useful in understanding red cell pathophysiology in normal and iron deficient patients.

Effects of diltiazem on the calcium accumulation and ATP synthesis simultaneously sustained by isolated rat heart mitochondria.

1. The effects of diltiazem have been investigated in isolated rat heart mitochondria exposed to conditions possibly attained in ischemia-damaged cells. 2. The results obtained indicate that diltiazem, at the concentrations expected within cells following pharmacological treatment, does not significantly affect the mitochondrial calcium content. 3. Diltiazem did not appear to modify ATP synthesis, and hence the capacity of mitochondria to sustain the ATP-requiring processes needed for the recovery of cardiac cells.