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Biomedical subjects

J Turney

Publications and source records attributed to J Turney.

16 recordsLinked to original sources

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Biology↗

Effective utilization of erythropoietin with intravenous iron therapy.

INTRODUCTION: Iron replacement therapy reduces the demand for erythropoietin (EPO) in some dialysis patients. It has been postulated that iron supply to the bone marrow is a rate-limiting step in the process of erythropoiesis under erythropoietin stimulation. METHODS: We evaluated the economic benefit of intravenous iron therapy for this purpose in a prospective, non-blinded study of 22 haemodialysis patients, 16 male, six female, mean age 62 years (range 24-80 years). All patients had a serum ferritin (SF) of < or = 60 microg/L, despite oral iron therapy. Patients with high aluminium and/or parathyroid hormone (PTH) levels, underlying bleeding/haematological disorders or active inflammatory diseases were excluded. Patients were established on subcutaneous EPO and given intravenous iron over seven consecutive dialysis sessions (total dose 1050 mg) and supplemental monthly doses with regular monitoring for 4 months. RESULTS: The median EPO dose was 4000 units/week (mean 6050 units/week) pre-treatment and 2000 units/week (mean 3700 units) at 6 weeks post intravenous iron therapy (P=0.03). No serious adverse events occurred in the 154 treatment sessions of intravenous iron. Mean haemoglobin (Hb) level remained constant at 6 and 12 weeks (P=0.087). Serum ferritin levels (P< 0.0001) rose significantly, while a reduction in transferrin saturation (TS) became significant at the end of the study (P=0.0047). The use of intravenous iron allowed a substantial monthly cost saving per patient in our unit. CONCLUSION: Intravenous iron therapy is a safe and cost-effective method for maintaining or improving Hb levels with a more effective utilization of EPO in patients with low SF levels despite oral iron therapy.

Adult↗

Evaluation of RBC ferritin and reticulocyte measurements in monitoring response to intravenous iron therapy.

Intravenous (IV) iron therapy can reduce erythropoietin (EPO) requirements in dialysis patients. Monitoring this response accurately is difficult. Estimation of red blood cell ferritin (RBCFer) and reticulocyte indices may give additional valuable information about iron availability to the erythroblasts (erythron). We evaluated the use of RBCFer, mean hemoglobin content of reticulocytes (CHr), and mean hemoglobin concentration of reticulocytes (CHCMr) in a prospective, nonblinded study of 22 hemodialysis patients (16 men and six women with a mean age of 62 years [range, 24 to 80 years]). All patients had an initial serum ferritin of < or = 60 microg/L. Patients with features known to produce EPO resistance and underlying bleeding/hematologic disorders were excluded. Patients were established on subcutaneous EPO and given IV iron therapy. The mean hemoglobin level remained constant throughout the study (P = 0.087). Serum ferritin and RBCFer increased significantly (P < 0.001 and 0.015, respectively) while a reduction in transferrin saturation became significant at the end of the study (P = 0.0047). A sharp increase in reticulocytes occurred in the first 14 days after commencement of IV iron, and there was an initial decrease in the percentage of hypochromic RBCs. An early decline in RBCFer was apparent. CHr increased with IV iron, indicative of increased iron supply to the developing erythron. Measurement of RBCFer and CHr provide evidence of increased iron supply for erythropoiesis during IV iron therapy. These measures help identify patients with functional iron deficiency and allow more accurate monitoring of response to IV iron therapy.

Adult↗

Public understanding of science.

The scientist's lament about public understanding of science is often heard. But scientific understanding is not merely a matter of scientific literacy; it also embraces issues of trust in scientists, doctors, and sources of information. People have an appetite for scientific information, and they are good at sifting the information relevant to their lives. Nonetheless, the onus will increasingly be on the scientist to explain scientific findings in ways that a range of public can use. So, we need to improve the scientist's understanding of the public.

Communication↗

Public understanding of medical discovery.

In February last year, the popular British magazine Woman's Own published an article headed 'Would you take a breast cancer test?'. It suggested that, 'women who have a family history are thought to be more at risk. Now, however, scientists have developed a blood test that can show if we're likely to get cancer. But would you want to know?'.

Attitude to Health↗

Life in the laboratory: public responses to experimental biology.

Present-day public attitudes to biological manipulation are ambivalent, many surveys show. This paper explores evidence of earlier attitudes to experimental biology, before survey data exists, by examining published responses in the press to the idea that biologists would 'create life'. This remarkable claim achieved wide currency in the early years of this century, particularly linked to the work of two prototypical 'visible scientists': Jacques Loeb and Alexis Carrel. Analysis of press responses to accounts of their work reveals deep disquiet about its possible implications, at a time when science and technology in general were regarded very positively. The evidence is augmented by studying commentary on a Presidential Address by Edward Schafer to the British Association meeting of 1912. It is concluded that feelings of ambivalence toward the manipulative power of biology are apparent at a very early stage in the development of modern biology, and that this makes it implausible that more recent manifestations of such ambivalence can be ascribed to some generalized 'anti-science' sentiment which has gathered strength in recent years.

Artificial Organs↗

Bacterial endocarditis of the tricuspid valve after insertion of a central venous catheter.

Central venous cannulation is a commonly used technique in the management of seriously ill patients. In experienced hands, the complication rate is low and primarily includes sepsis, thrombosis and local trauma. For chronic indwelling central venous catheters, thrombus formation within the right atrium has been described, particularly in premature infants, and a recent case has been reported in an adult. Valvular damage in the right heart is recognised and more often diagnosed at autopsy. This report describes the presence of tricuspid vegetations in a diabetic woman, related to the insertion of a central venous cannula.

Catheterization, Central Venous↗

Progressive systemic sclerosis, immunosuppression and necrotising arteritis: cause or effect?

Necrotising arteritis is rare in progressive systemic sclerosis (PSS). We report a patient with PSS who died with renal failure due to necrotising arteritis and segmental crescentic glomerulonephritis more typical of polyarteritis nodosa. Possible pathogenetic mechanisms are discussed. Renal biopsy is an important investigation in PSS, but is especially important in patients without hypertension, as other pathology needs to be excluded.

Administration, Oral↗

Hyperkalaemia in cyclosporin-treated renal allograft recipients.

Mean serum potassium levels were significantly higher for 9 months in renal allograft recipients receiving cyclosporin than in those receiving prednisolone and azathioprine. Sustained hyperkalaemia (serum potassium 6.0-7.1 mmol/l) inappropriate for their renal function (glomerular filtration rate 21-36 ml/min) developed in seven of forty-three cyclosporin-treated patients. All seven patients had hyperchloraemic acidosis; four were able to acidify their urine to pH less than or equal to 5.4. Six of the seven patients were hypertensive and receiving beta-blockers; one had had bilateral nephrectomy. Despite hyperkalaemia, plasma aldosterone levels were within the normal range in five patients and raised in two. During moderate sodium restriction, plasma renin activity was low or low-normal in five of the seven patients. In these patients a combination of hypoaldosteronism and renal tubular damage leading to a tubular defect of potassium and hydrogen ion secretion is the apparent cause of the hyperkalaemia and hyperchloraemic acidosis. Hyporeninaemia caused by beta-blockade probably blunts the aldosterone response to hyperkalaemia, thereby worsening it.

Acidosis↗

The effects of two different dosage regimens of sulphinpyrazone on platelet function ex vivo and blood chemistry in man.

When sulphinpyrazone (either 200 mg q.d.s. for 7 days or 400 mg b.d.s. for 5 days) was administered to human volunteers, inhibition of platelet function was observed ex vivo. The inhibitory effect was measured by the increase in the concentration of sodium arachidonate required to cause platelet aggregation and a decrease in the biosynthesis by the platelets of malondialdehyde from added sodium arachidonate. ADP-induced primary platelet aggregation was statistically significantly inhibited only on 1 day of the two studies. The inhibitory effect did not correlate with the plasma concentrations of unchanged sulphinpyrazone nor with its sulphone metabolite but correlated with the plasma concentration of the thioether metabolite (r = 0.577, p less than 0.001). Platelet count, plasma fibrinogen, beta-thromboglobulin, urea and creatinine concentrations were not changed by the drug but there was a clinically insignificant increase in bleeding time in all but one subject.

Bleeding Time↗