Search PubMed⌕ Search

Biomedical subjects

R M Rowan

Publications and source records attributed to R M Rowan.

At least 37 records · Page 2Linked to original sources
PubMed1984

Protocol for evaluation of automated blood cell counters. International Committee for Standardization in Haematology (ICSH).

This protocol is proposed for the evaluation of automated blood cell counters to assess the performance, advantages and limitations of such instruments. It is based on the International Committee for Standardization in Haematology (ICSH) 'Protocol for type testing equipment and apparatus used for haematological analysis' (1978a) and the British Committee for Standardization in Haematology 'Guidelines for the evaluation of instruments used in haematology' (Shinton, England & Kennedy, 1982). The document has been prepared by the ICSH Panel on Cytometry after discussion with colleagues. This tentative protocol will be reviewed 1 year after publication, in accordance with the ICSH rules, before it is adopted as a definitive standard.

Blood Cell Count↗
PubMed1984

The implications of assaying external quality control sera under 'special conditions'.

Two identical series of Wellcome quality control specimens were analysed by different procedures. One series was entered into the laboratory in the same way as patients' specimens while the other was analysed under special favourable conditions. This involved assaying the samples in replicate in different batches, omitting transcription errors and outliers, and placing the sample in a position following a calibration standard or an internal control. It was found that a significantly higher position in overall league ranking was achieved by assaying the control under 'special conditions'.

Blood Chemical Analysis↗
PubMed1982

Acute myelogenous leukaemia following cytotoxic therapy: five cases and a review.

Acute myelogenous leukaemia (AML) following cytotoxic chemotherapy has been reported increasingly. Five new cases are presented including the first described following treatment for immune thrombocytopaenia. A review of the literature has revealed 226 case reports of treatment-linked AML with sufficient detail to permit further study. Of the total of 231 patients, 76 (33 per cent) followed Hodgkin's disease, 59 (25.5 per cent) multiple myeloma, 22 (9.5 per cent) non-Hodgkin's lymphoma, 32 (14 per cent) other solid tumours and 42 (18 per cent) non-malignant diseases. The time interval from the start of chemotherapy to the diagnosis of AML was similar in all disease groups whether the patients had received radiotherapy or not. Differences emerged when the duration of exposure to chemotherapy was analysed in the individual disease groups; exposure was shorter in those patients treated for Hodgkin's disease and solid tumours than with the others suggesting that the pattern of administration of chemotherapy may be important. The effects of radiotherapy in addition to chemotherapy could not be defined precisely, but the study highlights the particular risk that appears to arise from alkylating agents, and the need to define optimal methods of administration of chemotherapy with minimal risk of inducing leukaemia.

Adolescent↗
PubMed1981

Comparison of Channelyser and Model S Plus determined platelet size measurements.

A comparison has been made between Coulter Counter ZBI/Channelyser C1000 derived platelet distribution width (PDW), mean platelet volume (MPV) and platelet crit (PCT) with similar measurements generated by the Coulter counter Model S Plus. Correlations of PDW and MPV from the two systems are poor; that for PCT is acceptable. The differing results can almost certainly be attributed to physical differences in the measurement systems.

Blood Platelets↗
PubMed1979

Assessment of the Coag-a-Pet Dual Channel in the routine haemostatic laboratory.

The Coag-a-Pet Dual Channel is an instrument which automatically records coagulation test end-points utilizing a photo-optical clot detection system. The instrument and its operation are described in detail. The capability of the instrument to perform tests of oral anticoagulant control, basic coagulation profiles and one-stage factor assays is assessed. In terms of precision and accuracy, the instrument performs well in carrying out the one-stage prothrombin time, Thrombotest, activated partial thromboplastin time using an automated APTT reagent but not kaolin, and one-stage factor assays. The thrombin clotting time can not be measured on this instrument. The instrument is most suitable for batched repetitive tests, reducing observer error and improving laboratory efficiency.

Blood Coagulation Factors↗
PubMed1979

The Coulter Counter Model S Plus--the shape of things to come.

The Coulter Counter Model S Plus is a 12 parameter haematological analyser designed for service use in haematology laboratories. Eight parameters are standard in current routine haematological practice; the seven parameters generated by the Model S and a platelet count. The method of platelet counting is unique. The remaining parameters are new and comprise the platelet-crit, the mean platelet volume and size distribution measurements for both platelets and red cells. A description of the instrument is given including differences from the Model S. The new parameters are discussed in detail. Instrument precision is assessed in terms of linearity, reproducibility, drift, carry-over and protein build-up. The results of all are impressive. Instrument accuracy is assessed in detail; white cell count, red cell count, haemoglobin concentration and mean corpuscular volume being compared with those values measured by the Model S; the Model S Plus haematocrit is compared with the microhaematocrit and platelet counts with those from the Thrombocounter C/Thrombofuge system. All correlations are very satisfactory. Normal values are defined for the new parameters. Instrument design and function are assessed and reagent consumption quoted. Cell control reagents have been evaluated. A realistic hourly throughput for the Model S Plus is 70-80 samples.

Automation↗
PubMed1977

Evaluation of a semi-automated platelet-counting system.

Coulter Electronics Ltd have produced a semi-automated platelet-counting system. Platelet-rich plasma may be obtained either by tube sedimentation or by means of the Thrombo-fuge, the latter being an instrument designed to produce accelerated sedimentation. The instrument is linear over the entire range of platelet counts, and machine reproducibility is good. Comparison of machine-rated with visual counts satisfied statistical evaluation. The technique can be handled by one operator and platelet counts can be achieved at the rate of 30 per hour by both methods although individual counts on the Thrombo-fuge may be obtained in approximately one-quarter of the time required for tube sedimentation. The throughput using the Thrombo-fuge could certainly be doubled were two sample plates supplied. Few problems were encountered during the evaluation and most could be avoided by meticulous technique. Visual counts must be performed when the sample haematocrit is greater than 50%-Discrepant counts have been obtained in patients with white cell counts exceeding 50 X 10(9)/1 and in patients with giant platelets. ESR elevation for any reason does not lead to serious discrepancy in results. The incidence of platelet clumping due to the presence of platelet agglutinins and of microclot formation due to inadequate mixing is probably much higher than is commonly thought, and certainly peripheral blood film scrutiny should never be omitted in patients with low counts. Careful examination of peripheral blood films must be combined with instrument counting for some time lest further causes of discrepant counting emerge.

Blood Platelets↗
PubMed1977

Myelomatosis.

Explore the source record for details and available documents.

Acute Kidney Injury↗
PubMed1976

An assessment of the clinical usefulness of plasma ribonuclease assays.

The usefulness of plasma ribonuclease assays was studied in (i) patients with possible protein deficiency, (ii) patients with myelomatosis, (iii) patients with carcinoma of the breast. In each group, the major factor associated with elevation of plasma ribonuclease was impairment of renal function. The assay was therefore of little value in the assessment of patients with myelomatosis or carcinoma of the breast. However, in the patients with possible protein deficiency and normal renal function, an elevation of plasma ribonuclease is, in general, associated with a decrease in serum albumin, transferrin and cholinesterase. Plasma ribonuclease may therefore be a useful parameter in the assessment of protein nutritional status.

Acute Kidney Injury↗
PubMed1975

Neisseria catarrhalis septicaemia in acute lymphoblastic leukaemia.

A case of septicaemia due to Neisseria catarrhalis occurring in an immunosuppressed individual is described. The clinical syndrome closely resembled that of N. meningitidis septicaemia. The potential pathogenicity in the immunosuppressed patient, of organisms usually considered harmless is stressed.

Acute Disease↗
PubMed1974

A further application of the nitroblue tetrazolium test.

The nitroblue tetrazolium (N.B.T.) test was performed on patients in whom a differential diagnosis of pulmonary thromboembolism or lobar pneumonia existed. The mean N.B.T. score in healthy subjects was 6.4% (range 1%-15%). Patients with uncomplicated pulmonary thromboembolism showed a mean N.B.T. value of 7.5% (range 3%-12%). In patients with lobar pneumonia the mean N.B.T. score was 42.4% (range 21%-85%). These results suggest that the N.B.T. test is of value in the differential diagnosis of pulmonary thromboembolism and lobar pneumonia.

Adolescent↗