PubMed Health⌕ Search

Biomedical subjects

I Cavill

Publications and source records attributed to I Cavill.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of erythropoiesis after bone marrow transplantation: quantitative reticulocyte counting.

Erythroid regeneration is an important and separate element in the engraftment process in allogeneic and autologous bone marrow transplantation (alloBMT, autoBMT). Qualitative visual reticulocyte counting has proved inadequate in the evaluation of erythropoiesis after BMT but automated flow cytometry now allows the reliable quantitation of reticulocytes even to very low levels. Reticulocyte counts and highly fluorescent reticulocyte (HFR) counts (very early reticulocytes) were estimated daily in recipients of 22 autoBMT and 14 alloBMT using a Sysmex R-1000 automated reticulocyte counter. Marrow ablation caused an immediate and rapid fall in both the reticulocyte count and the HFR. Measurable numbers of reticulocytes persisted throughout the hypoplastic period, but HFR fell to zero in the majority of both the autoBMT and alloBMT. HFR rose significantly after a median time of 14 d post-autoBMT, and 12 d post-alloBMT. Attainment of 15 x 10(9)/l reticulocytes and 0.5 x 10(9)/l HFR at day 21 post-transplant was associated with ultimate engraftment in 100% cases. Inadequate engraftment was seen in the majority of patients whose responses fell below these levels. Graft-versus-host disease was associated with a transient slight reduction in reticulocyte count. Neither episodes of infection nor blood transfusions had any significant impact on trends of reticulocytes or HFR. Automated flow cytometric reticulocyte counting has been shown to provide an accessible measure of erythroid activity which may be of predictive value in the management of patients following bone marrow transplantation.

Blood Cell Count↗
PubMed1991

Comparison of a modified thiazole orange technique with a fully automated analyser for reticulocyte counting.

Two independent methods for quantitating reticulocyte counts were compared. One used a modified thiazole orange technique and a flow cytometer (Becton Dickinson FACS); the other was a fully automated whole blood analyser (Sysmex R1000). Both methods gave comparable results with a coefficient of variation of less than 5%. Samples measured using the R1000 showed a negligible decrease in the reticulocyte count over five days at room temperature, although there was evidence of continuing intracellular maturation: with thiazole orange there was an apparent increase. A practical reference range of 20-70 x 10(9)/l was established from 89 normal subjects. The close correlation between the two independent estimates indicates the validity of the quantitation of the reticulocyte count and shows that automation allows significant changes within and below the normal range to be detected with a degree of reliability which was not previously possible.

Benzothiazoles↗
PubMed1990

Treating renal anaemia with recombinant human erythropoietin: practical guidelines and a clinical algorithm.

Treatment with erythropoietin is highly effective and beneficial if given with care. In view of its cost, however, it is essential to exclude and treat other causes of anaemia before considering using this hormone. After treatment is started the important points for success are regular review of iron availability state combined with a slow correction of the anaemia. Failure of response requires a thorough search for a possible cause, which should be corrected before considering an increased dose of the hormone. Regular monitoring for potential complications, particularly a rise in blood pressure, is required.

Algorithms↗
PubMed1990

The treatment of renal anaemia in CAPD patients with recombinant human erythropoietin.

Fifteen severely anaemic patients receiving CAPD were treated with subcutaneous recombinant human erythropoietin (Epo). Ten subjects had a good response with the haemoglobin concentration increasing from less than 8 g/dl to greater than 10 g/dl within 16 weeks. Four patients had a poor response, which was due to infection in two, myelofibrosis in one and unknown cause in another. Epo was ineffective in the remaining individual, probably due to the presence of occult metastatic carcinoma. Iron supplementation in the form of intravenous iron dextran was given to 12 patients when transferrin saturation decreased below 20%. There was a significant increase in red cell volume (P less than 0.005), with a decrease in plasma volume (P less than 0.005). Red cell iron turnover increased (P less than 0.05) but there was no change in red cell lifespan or deformability. Biochemical parameters remained unaltered, as did peritoneal function. Exercise duration improved (P less than 0.001), as did maximal oxygen consumption (P less than 0.01). Four patients required an increased dose of hypotensive drugs. Epo is a safe effective therapy for the anaemia of CAPD subjects.

Adult↗
PubMed1979

Erythropoiesis and iron metabolism in Hodgkin's disease.

Recently developed techniques for the investigation of iron kinetics were used to study the disturbance of iron metabolism in 19 untreated patients with Hodgkin's diseases (HD). The erythroid abnormality in newly diagnosed HD appears to be confined to those patients with systemic symptoms of weight loss, night sweats and fever, and consists of depression of marrow erythroid activity. These patients had a significnatly lower haemoglobin and serum iron concentration and a higher serum ferritin concentration, both when compared to normal subjects and to those patients with HD who lacked systemic symptoms. Ineffective erythropoiesis and red-cell destruction were not significantly increased. The present findings, confirm that HD patients with systemic symptoms have a depression of erythropoiesis, and that in these patients the marrow fails to respond to the stimulus of mild anaemia.

Adolescent↗
PubMed1979

Erythropoiesis, iron stores and tissue iron exchange in man.

1. The exchange of iron between plasma and erythroid and non-erythroid tissues was measured in 14 normal subjects, 17 iron-deficient patients, nine patients with primary idiopathic haemochromatosis and in 13 patients with haemolytic disorders. 2. The two main factors determining tissue iron turnover were shown to be the level of iron stores and the erythropoietic activity of the bone marrow.

Adult↗
PubMed1979

An evaluation of two methods of laboratory quality control.

Two methods for quality control of automated blood counters have been compared: (1) monitoring results from patients' samples, and (2) analysis of results of a stable whole-blood control. The latter method proved better able to distinguish calibration changes from patient variation.

Erythrocyte Indices↗
PubMed1979

Measurement of haemolysis in patients with prosthetic heart valves.

Haemolysis following prosthetic heart valve insertion can be precisely and sensitively measured by means of a 59Fe ferrokinetic technique. Results obtained in a small series of patients with either Starr-Edwards or Brunwald-Cutter valve replacement are presented.

Aortic Valve↗
PubMed1979

A method for the investigation of reticuloendothelial iron kinetics in man.

A colloidal suspension of hydrolysed radio-iron of high specific activity has been developed for the investigation of reticuloendothelial (RE) iron kinetics in man. Following intravenous injection this material is cleared rapidly by the RE system and the iron released intn to the endogenous RE iron load, and it has proved possible to measure RE iron release without disturbing the normal iron flow.

Anemia, Hypochromic↗
PubMed1979

Variability of serum ferritin concentration in normal subjects.

Serum ferritin concentrations were measured in normal subjects over periods of 1 day, 1 week and 7 weeks. The variation of the results was compared with variation of control of control sera. In most of the subjects the variation in the results could be attributed to the variation in the method of measurement. No diurnal variation in serum ferritin concentration was observed.

Circadian Rhythm↗
PubMed1978

Ferrokinetics: methods and interpretation.

The measurement of erythroid activity is based on the study of plasma iron kinetics. The radioiron injected should be bound specifically to transferrin, and the measurement of plasma 59Fe activity should be corrected for variation in plasma iron concentration. In addition, 59Fe-transferrin activity should be measured free of 59Fe-haemoglobin contamination. Analysis of the plasma 59Fe clearance curve over 14 days can give measures of total, effective and ineffective erythropoiesis, together with the red cell lifespan. Simpler ferrokinetic studies cannot be reliably used to assess erythropoiesis.

Bone Marrow↗