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Biomedical subjects

R M Rowan

Publications and source records attributed to R M Rowan.

44 records · Page 3Linked to original sources
PubMed1973

Routine application of the nitroblue tetrazolium test in the clinical laboratory.

A modified nitroblue tetrazolium test (NBT) is described which is suitable for routine application in the haematology or bacteriology laboratory and which provides a rapid aid to the diagnosis of bacterial infection. Hitherto published methods have recommended the use of heparinized whole blood samples for the performance of the NBT test. However, we have demonstrated that the use of the sucrose polymer Ficoll permits the test to be carried out on buffy coats prepared from venous blood anticoagulated in sequestrene (EDTA). The mean percentage of NBT-positive neutrophils in 60 healthy control subjects was 6.1. The mean percentage of NBT-positive neutrophils in 56 patients with confirmed or presumed bacterial infection was 34.2. Scores within the normal range were observed in 13 patients in this group. Forty-eight individuals with viral infection yielded a mean percentage of NBT-positive neutrophils of 8.5. Six patients in this group gave scores above the upper limit of normal. Both pathological groups are described in detail and applications of this test are suggested.

Bacterial Infections↗
PubMed1972

Evaluation of an automatic platelet counting system utilizing whole blood.

Technicon's newly developed platelet AutoCounter utilizes an electro-optical system which detects and counts particles by sensing the scattering of light which occurs when blood cells flow through the illuminated sensing chamber of a micro-optical system. The system utilizes whole blood collected into EDTA. Blood samples, which can be handled at the rate of 40 per hour, are diluted with 2M urea which in addition causes lysis of the erythrocytes. The haemolysate thus obtained is delivered to the particle counter after a two-minute reaction time, the cell count finally being displayed on a continuous chart recorder. An evaluation of this machine has been carried out in the Department of Haematology, the Royal Infirmary, Edinburgh, on hospital specimens from patients suffering from a wide variety of diseases. The results of this evaluation are presented. Reproducibility studies indicate a coefficient of variation of 4% at any platelet level. The percentage drift per sample ranges from +0.4 to -0.4% of the total count. Carry-over and departures from linearity are statistically significant; however, the magnitude of these deviations is not sufficient to cause concern in routine use. Acceptable agreement is noted between machine counts and the counts obtained by technicians using phase-contrast microscopy with the exception of two anomalous individuals. Discrepant counts were noted in patients with elevation of the erythrocyte sedimentation rate and also in patients with disturbance of immunoglobulins. A modification to the sampling probe which eliminates the former problem is described. The AutoCounter described in this paper provides a fast, reliable, and accurate service laboratory platelet counting system.

Analysis of Variance↗