Bone Mineral Content Measured by Direct Photon Absorptiometry in a Normal Population and in Patients on Maintenance Haemodialysis

Bone mineral assessment, by monoenergetic photon absorption in vivo, has been carried out at a standard site in the radial shaft of 39 male and 54 female control subjects from a normal population, and in 13 patients who have been on maintenance haemodialysis for periods varying between 3 months and 5 years. Mean bone mineral content (±S.D.) was 1.22 ± 0.13 g. per cm. of shaft segment length for the normal male and 0.87 ± 0.08 g. per cm. for the normal female control subjects. Only 2 of the haemodialysed patients had values outwith the 95 per cent confidence limits of the normal range. In the patients a correlation was noted between the current plasma alkaline phosphatase level and the bone mineral content. Bone scanning by photon absorption is recommended as a convenient and sensitive method for routine clinical assessment of bone status.

Bone marrow iron and plasma ferritin in dialysed patients given intravenous iron-dextran

Bone marrow biopsies have been taken in 28 patients on or approaching maintenance haemodialysis before and after treatment with monthly intravenous iron-dextran (Imferon). Stainable marrow iron was compared with blood Hb, plasma ferritin, erythrocyte protoporphyrin and MCH levels at the time of biopsy, and with previous or subsequent responses to iron in terms of blood Hb and MCH. There was a positive correlation between bone marrow iron and plasma ferritin levels both before and after iron therapy. All the patients with excess marrow iron had high plasma ferritin. However, six patients with low or normal marrow iron also had high plasma ferritin, two of these before iron therapy was given. Seven of the eight patients with no detectable marrow iron had low plasma ferritin. Three of the 28 patients failed to respond to iron with an increased blood Hb. MCH increased in all patients studied during iron therapy. All but one of the patients with high plasma ferritin prior to iron therapy responded well to iron. Although a good correlation between plasma ferritin and marrow iron can be shown in dialysed patients given intravenous iron-dextran, a high plasma ferritin level in an individual patient should not by itself preclude iron therapy.

Peripheral microcirculatory blood flow in haemodialysis patients treated with erythropoietin

BACKGROUND

Haemodialysis patients have abnormal blood vessels, and increased morbidity from vascular causes, effects which may potentially be enhanced by erythropoietin (EPO) therapy.

METHODS

Microcirculatory blood flow was assessed using a laser-Doppler flowmeter in a group of 19 haemodialysis patients before and during treatment with recombinant human (EPO).

RESULTS

Haemodialysis patients had significantly impaired microcirculatory blood flow under both basal (25 degrees C) and hyperaemic (44 degrees C) conditions by comparison with 19 normal controls (baseline flow, median and range: patients 1.54 (0.28-2.54) volts, controls 3.39 (0.94-5.23) volts, p < 0.001 Mann Whitney U Test; hyperaemic flow, patients 2.69 (1.08-3.82) volts, controls 3.81 (1.32-8.00) volts, p < 0.001). There was no significant influence on microcirculatory blood flow of patient age, duration of haemodialysis, short-term EPO therapy (subcutaneous or intravenous), therapy with a calcium-channel blocker/vasodilator (nifedipine), or radiological evidence of vascular calcification.

CONCLUSIONS

Haemodialysis patients have an abnormal peripheral microvasculature, which may be relevant to their increased risk of ischaemic tissue damage and poor wound healing.

Effect of nifedipine on changes in fibrinogen and von Willebrand factor in haemodialysis patients treated with recombinant human erythropoietin

Erythropoietin (EPO) therapy in haemodialysis patients may be associated with the development of hypertension and vascular access thrombosis. Raised levels of fibrinogen and von Willebrand factor have been implicated in the pathophysiology of thrombosis under these circumstances. The effect of nifedipine, used to treat EPO therapy-related hypertension, on levels of fibrinogen and von Willebrand factor antigen (vWf) was studied in a group of 21 EPO-treated haemodialysis patients. Significant increments in both fibrinogen and vWf following EPO therapy were observed in the 13 patients who did not receive nifedipine (fibrinogen (median range), pre-EPO: 3.73 (2.41-6.38) mg/ml, post-EPO: 4.59 (3.03-8.80) mg/ml, P < 0.05; vWf pre-EPO: 183 (118-374)% normal, post-EPO: 253 (124-392)% normal, P < 0.01). Similar changes were not seen in the eight nifedipine-treated patients (fibrinogen, pre-EPO: 3.35 (2.58-6.32) mg/ml, post-EPO: 3.36 (2.69-7.20) mg/ml, P = NS; vWf, pre-EPO: 176 (104-298)% normal, post-EPO: 175 (82-371)% normal, P = NS). These effects were independent of blood pressure control. The use of nifedipine to treat EPO therapy-related hypertension may therefore potentially help to reduce the risk of vascular access thrombosis.

Persistence of microflora in biofilm within fluid pathways of contemporary haemodialysis monitors (Gambro AK-10)

Growth of bacteria within a biofilm, visible macroscopically as a yellow coating, was seen on the interior walls of semi-transparent plastic dialysis monitor fluid pipes. The level of bacterial growth along the water/dialysis fluid pathway, and the effect of in-line bacterial filters, on colony counts in reverse osmosis reject water and monitor effluent were examined. Little difference in colony counts was seen at either sampling point in monitors fitted with and without filters. Because of the increasing use of high-flux dialysis, and its potential for transmembrane transport of endotoxin and bacteria into patients, staff should be aware that dialysis fluid pathways may be colonized with viable bacteria, which are not readily killed by conventional heat and chemical cleaning processes.

Erythropoietin response and route of administration

The effect of route of erythropoietin (EPO) administration was assessed in sixteen hemodialysis patients who completed a randomised crossover study of thrice weekly subcutaneous (SC) and intravenous (IV) erythropoietin with an EPO-free washout period separating the two phases of treatment. Route of EPO administration had no significant effect on absolute reticulocyte counts, and change in hemoglobin (Hb) during the first six weeks of therapy, at a constant EPO dose (120 iu/kg/week). Similarly, there was no significant difference in EPO dose requirement between the two routes, both during and after correction of anemia, and after maintenance of target Hb (10-12 g/dl) for an eight-week period (end of maintenance period dose; median [range]; SC EPO: 120 [30-367] iu/kg/week, IV EPO: 124.5 [37-377] iu/kg/week). Following EPO withdrawal, Hb fell at a rate of 0.38 (0.14-0.69) g/dl/week. Route of EPO administration did not influence the incidence of thrombotic and hypertensive side effects, or increases in dialysis heparin requirement and albumin, and decreases in ferritin, alpha-1-antitrypsin and ceruloplasmin during the study period. In conclusion, thrice weekly SC and IV EPO are comparable in terms of efficacy and safety.

Effect of erythropoietin therapy and withdrawal on blood coagulation and fibrinolysis in hemodialysis patients

Erythropoietin (EPO) therapy in hemodialysis patients may be associated with an enhanced risk of vascular access and extracorporeal thrombosis. Assessment of blood coagulation and fibrinolysis was performed monthly on a group of 21 hemodialysis patients treated with EPO, and on four iron-deficient hemodialysis patients treated with iron dextran infusions alone. Seventeen of the EPO treated patients were also monitored after withdrawal of EPO to allow hemoglobin to fall to pre-EPO levels, and 16 of these patients during a second subsequent phase of EPO therapy with EPO administered using the alternative route (subcutaneous/intravenous) from the first phase of treatment. Ten untreated hemodialysis patients with intrinsically high hemoglobins were studied as controls. EPO was associated with significant increases in the endothelial product Factor VIII von Willebrand factor antigen (FVIIIvWFAg), and plasma fibrinogen, to levels comparable to those observed in the untreated control patients. Both FVIIIvWFAg and fibrinogen remained significantly elevated when EPO was withdrawn. Whole blood platelet aggregation (spontaneous, collagen, and ADP-induced) also increased following EPO, collagen and ADP-induced aggregation, increasing further when EPO was withdrawn. Transient but significant changes occurred in plasma measures of thrombin-antithrombin III complex, prostacyclin stimulating factor, and protein C during the first EPO treatment phase, and also thrombin-antithrombin III complex during the second treatment phase, all favoring a tendency to thrombosis. D-dimer increased significantly following EPO withdrawal. Erythrocyte deformability, and granulocyte aggregation did not change. There was no effect of route of EPO administration (subcutaneous or intravenous) or EPO dose on any of these parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen free radicals and platelet and granulocyte aggregability in renal transplant patients

Oxygen free radical reaction products (plasma malondialdehyde), the free radical scavengers plasma thiol and red cell superoxide dismutase (SOD), and whole blood platelet and granulocyte aggregation were measured in 23 renal transplant patients and 23 age-matched controls. Malondialdehyde-like material (MDA) was significantly increased in transplant patients compared with controls (transplants MDA [median, range], 7.7 [5.3-11.5] nmol/ml; controls MDA, 6.3 [5.4-8.7] nmol/ml; P < 0.001). The patients also had increased red cell superoxide dismutase (transplants SOD, 128.1 [89.4-93.8] U/0.5 ml red cells; controls SOD, 95.9 [62.0-132.6] U/0.5 ml red cells; P < 0.001) and reduced plasma thiol (transplants thiol, 428 [266-496] mumol/L; controls thiol, 445 [358-501] mumol/L; P < 0.05). These factors were not influenced by immunosuppressive therapy, duration of transplantation, or creatinine concentration. Transplant patients had significantly higher levels of collagen-induced and spontaneous whole blood platelet aggregation compared with controls (collagen: transplants, 72 [4-93%]; controls 43 [6-94]%; P < 0.001; spontaneous: transplants 46 [11-93]%; controls 37 [10-75]%; P < 0.05). Spontaneous platelet aggregation, however, was significantly correlated with creatinine concentration (r = 0.525, P < 0.02, Spearman's correlation), and was raised only in those patients with a degree of renal impairment. Granulocyte aggregation was increased in patients receiving cyclosporine (CsA [n = 15], 57 [36-66]%; no cyclosporine [n = 8], 45 [37-62]%; controls [n = 23]; 39 [31-61]%; P = 0.004). Renal transplant patients are subject to oxidative cell damage, and may be at increased risk of vascular thrombosis. Possible contributory factors include an immunological reaction to the graft and/or the effects of immunosuppressive therapy.

Evaluation of a nisin-based germicidal formulation on teat skin of live cows

A purified preparation of the nontoxic antimicrobial peptide, nisin (AMBICIN N), was used in the formulation of a germicidal sanitizer suitable for use on cow teats. The germicidal activity of the formulation against mastitis pathogens was measured on teat skin of live cows. The nisin-based formulation gave a mean log reduction of 3.90 against Staphylococcus aureus and 4.22 log reduction against Escherichia coli after exposure for 1 min to the germicide. This activity was comparable with that exhibited by a 1% iodophor teat dip but was significantly greater than that exhibited by the .1 and .5% iodophors and by the .5% chlorhexidine digluconate teat dips. The nisin-based formulation showed little or no potential for skin irritation after multiple application to skin, but iodophor and chlorhexidine digluconate teat dips showed significant potential for skin irritation in comparable studies.

Effect of dialyzer geometry during hemodialysis with cuprophane membranes

The effect of dialyzer geometry, both flat plate (FP) and hollow fiber (HF), on platelet and granulocyte activation during dialysis with cuprophane membranes was studied in 12 patients. A subset of six patients was restudied after correction of their anemia with recombinant human erythropoietin (EPO). Granulocyte count and aggregation in vitro fell significantly (P less than 0.01) at 20 minutes of dialysis, followed by a gradual return towards pre-dialysis values at 240 minutes. Malondialdehyde (MDA), a product of free radical reactions generated by activated granulocytes, increased significantly during dialysis [predialysis MDA (median, range): 8.4 (5.8 to 11.6) nmol/ml, 240 minutes MDA: 9.7 (6.6 to 12.5) nmol/ml, P less than 0.01 Wilcoxon test). This increase, however, was not affected by dialyzer geometry or EPO therapy. Neither type of dialyzer was associated with significant platelet loss at the end of dialysis. Whole blood platelet aggregation in vitro (spontaneous and collagen-induced) decreased significantly, (P less than 0.01) during dialysis, the fall in spontaneous aggregation being significantly less following EPO therapy [spontaneous aggregation 240 minutes; pre-EPO: 34 (13 to 52)%; post-EPO 50: (16 to 76)%, P less than 0.01)]. The ratio of the platelet release proteins beta-thromboglobulin and platelet factor 4 increased significantly during dialysis, indicating platelet activation in vivo, although there was no effect of dialyzer geometry or EPO. Factor VIII von Willebrand Factor antigen, a putative marker of endothelial damage, was raised pre-dialysis, and increased further during dialysis, irrespective of dialyzer geometry or EPO. In conclusion, dialyzer geometry had no significant effect on granulocyte and platelet counts and activity during hemodialysis with cuprophane membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Urine transparency as an index of absence of infection

A visual assessment of the clarity of urine was used as an exclusion test to indicate the absence of infection; verified by dipslide culture, it was applied to 363 urine samples collected from patients attending 2 adult nephrology clinics over a period of 6 months. The crimped aluminium bowl used for collection of samples assisted the assessment of clarity. The sensitivity of the method compared with dipslide culture was 73%, with specificity and efficiecy both 58%. The predictive value of a negative test (clarity) was 97% with a false negative rate of 3%, enabling this simple examination to be used as an exclusion test for further testing. In simple terms, a clear urine is unlikely to be infected. It is also an advantage to have an immediate indicator of the absence of infection available at the clinic. Analysis of only those urines assessed as cloudy could result in financial savings and, from the clinics, a 56% reduction in workload.

Microbial growth and blockage of sub-floor drains in a renal dialysis centre: a problem highlighted

The accumulation of microorganisms embedded in biofilm within the drainage pipework leading from individual dialysis monitors in a renal dialysis centre, represents a significant threat to the safe operation of the whole centre due to blockage of the pipes and overflow of waste water. Attempts to disperse the growth with chemicals and disinfectants have been unsuccessful. Only mechanical rodding has removed the deposit, and regrowth has occurred. Those planning new dialysis centres should ensure that effluent pipework is readily accessible with multiple rodding eyes and is made of material able to withstand rodding and chemicals.

Atrial natriuretic factor improves renal function and lowers systolic blood pressure in renal allograft recipients treated with cyclosporin A

OBJECTIVE

Atrial natriuretic factor (ANF) has several properties which suggest that it may ameliorate cyclosporin A nephrotoxicity. We therefore investigated the response to a pharmacological dose of ANF in renal transplant recipients treated with cyclosporin A.

DESIGN

A single-blind randomized crossover design comparing the renal and haemodynamic effects of D-glucose (placebo) with ANF.

METHODS

Seven patients with stable renal function following renal transplantation were studied under maximal water diuresis. Glomerular filtration rate and effective renal plasma flow were estimated from clearances of inulin and para-aminohippurate, respectively.

RESULTS

Plasma ANF levels increased significantly in association with increased diuresis and natriuresis. Glomerular filtration rate was unchanged after placebo but increased significantly after ANF fusion. Likewise, effective renal plasma flow increased significantly with ANF infusion. There was a significant fall in systolic blood pressure, with no apparent change in heart rate and diastolic blood pressure.

CONCLUSIONS

These results suggest that ANF may have beneficial effects in protecting against cyclosporin A-induced nephrotoxicity and hypertension.

Parathyroidectomy in uraemic hyperparathyroidism: a clinical study

Osteodystrophy is a common and sometimes debilitating complication of renal failure. Hyperparathyroidism plays a crucial role in the development of this condition. Significant morbidity is also incurred by the effects of calcium deposition in other tissues. We report a series of 27 patients undergoing parathyroidectomy between May 1988 and November 1989. All had biochemical, radiological and clinical evidence of hyperparathyroidism. Surgery was well tolerated leading to an improved quality of life and avoidance of the need for aluminium containing phosphate binders.

Prothrombotic effect of erythropoietin in dialysis patients

Thrombin-antithrombin III complex concentrations (TAT-III) were measured in 18 anaemic haemodialysis patients treated with erythropoietin (Epo) and in four haemodialysis patients treated with i.v. iron dextran. There was a significant early increase in thrombin-antithrombin III in erythropoietin-treated patients which appeared to be independent of the response to erythropoietin (Epo responders (n = 14), pretreatment TAT-III median (range) 3.10 (2.70-9.10) micrograms/l; maximum TAT-III 19.48 (11.18-60.00) micrograms/l, P less than 0.001, Wilcoxon; Epo non-responders (n = 4), pretreatment TAT-III 3.15 (2.90-4.50) micrograms/l, maximum TAT-III 16.00 (10.31-36.12) micrograms/l, P less than 0.001). This was not seen in iron-dextran-treated patients (Pretreatment TAT-III 2.05 (1.90-9.48) micrograms/l, maximum TAT-III 5.60 (2.10-14.50) micrograms/l). The change was not related to haemoglobin, erythropoietin dose, or method of administration, and was transient in nature, thrombin-antithrombin III returning to pretreatment values after approximately 6 months in all patients (Epo responders 6.0(4.0-9.0) months, TAT-III 2.47 (1.30-9.23) micrograms/l; Epo non-responders 7.0 months, TAT-III 5.04 (2.10-7.00) micrograms/l). Increased thrombin-antithrombin III complex may reflect an effect of erythropoietin on microcirculatory factors, which could be relevant to the occurrence of adverse events during treatment.

Whole blood granulocyte aggregation in vitro in dialysis-dependent patients

Whole blood granulocyte aggregation in vitro was measured in 17 haemodialysis (HD) patients, 18 continuous ambulatory peritoneal dialysis (CAPD) patients, and 30 age-matched normal controls. Granulocyte aggregation was significantly increased in dialysis-dependent patients compared to controls (P less than 0.001) and was statistically significantly higher in CAPD patients compared to HD patients (P less than 0.01). [CAPD patients, median (range): 56.5 (44-71)%; HD patients: 53.0 (32-67)%; Controls; 42.5 (33-56)%.] Since granulocyte hyperaggregability has been linked with the pathogenesis of ischaemic vascular disease, abnormal granulocyte activity in dialysis-dependent patients may be of many factors contributing to their increased cardiovascular morbidity.

Erythropoietin and spontaneous platelet aggregation in haemodialysis patients

Erythropoietin significantly, reversibly, and reproducibly increased in-vitro whole-blood spontaneous platelet aggregation in 15 patients on haemodialysis. During erythropoietin treatment, spontaneous platelet aggregation was significantly higher in these subjects than in non-uraemic controls; concomitant treatment with 300 mg aspirin daily reversed platelet hyperaggregability. Erythropoietin may promote thrombosis by an effect on platelet function.

Massive cystic hepatomegaly in a female patient with polycystic kidney disease treated by combined hepatic and renal transplantation

A patient with cystic kidney disease of adult onset and severe cystic hepatomegaly is presented. The patient was severely disabled solely by her abdominal bulk. Simultaneous liver and renal transplantation was undertaken successfully.

Aluminium content of water for injection used with recombinant human erythropoietin

Human recombinant erythropoietin is of proven value in the treatment of the anaemia of renal failure. The aluminium content of 36 ampoules of water for injection supplied for use with recombinant erythropoietin has been measured and ranged from 24 to 450 micrograms/l, with a median of 251 micrograms/l. In three samples, which may have been contaminated on opening, the range was from 1770 to 6160 micrograms/l. In Water for Injection BP, values ranged from 66 to 140 micrograms/l with a median of 99 micrograms/l. Reconstituted erythropoietin did not contain any more aluminium than could be accounted for by the water. Ampoules of a second brand of erythropoietin, supplied already in solution, contained from 506 to 837 micrograms/l aluminium (median 682 micrograms/l). In view of the lifelong duration of erythropoietin therapy clinicians and pharmaceutical companies should be aware of this potential problem. Although the amount of aluminium delivered with each injection is usually less than 4 micrograms, it is suggested that active steps are taken to establish a British Pharmacopoeia limit on the aluminium content of injections.

Calcium carbonate 1250 mg/1260 mg: an effective phosphate binder

Calcium carbonate is currently the first choice phosphate binder in renal failure. In the UK its most widely prescribed formulation is a combination of calcium carbonate 420 mg and glycine 180 mg (Titralac 3M Riker). In order to achieve adequate reduction in the serum phosphate level, up to 12 of these tablets may be required daily. In a group of seven patients, we have compared Titralac with two alternative preparations containing calcium carbonate 1250 mg (Calcium-500 Macarthy's Medical Ltd) and calcium carbonate 1260 mg (Calcichew Shire Pharmaceuticals Ltd). Given at a third of the daily number of Titralac tablets, both these newer preparations were effective phosphate binders and produced no statistically significant change in serum calcium and phosphate. The important advantage of such a reduced tablet load is improved patient compliance with phosphate binder therapy. Calcium-500 is also a cost-effective treatment slightly reducing the cost when compared with combined calcium carbonate 420 mg and glycine 180 mg.

Oral ciprofloxacin in the treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis

Oral ciprofloxacin in doses of 0.75 to 2 g daily for 8-16 (median 10) days was given as first-line treatment of 33 unselected episodes of CAPD-associated peritonitis in 20 patients. Treatment was well tolerated and effective, curing 25 episodes. Treatment was withdrawn in five episodes, four because of resistant organisms and in the other because of vomiting. Infection relapsed twice in one patient during follow-up and one patient had persistence of the infecting organism (Pseudomonas aeruginosa) despite clinical improvement. Plasma and dialysate ciprofloxacin levels ranged from 1 to 8 mg/l. Assay between days 2 and 4 of treatment indicated the ciprofloxacin steady state concentration. If this proves to be greater than 7 mg/l the dose may be reduced and if less than 2 mg/l the dose should be increased. Overall a single course of oral ciprofloxacin was 76% successful as a first-line treatment for CAPD-associated peritonitis, caused by a wide range of organisms.

Hepatic iron in dialysed patients given intravenous iron dextran

Five percutaneous biopsy and 17 necropsy liver specimens were analysed histologically and chemically for iron content in 22 patients receiving dialysis for chronic renal failure, 13 of whom were given intravenous iron-dextran. Brissot scores for assessing histological hepatic iron deposition and chemically measured liver iron concentrations correlated closely. Both variables depended on total cumulative dose of iron, and to a lesser extent, on time since the last dose. Fibrosis (seen in five patients) was minimal and non-specific. Electron microscopic examination showed that there was no generalised damage and confirmed the presence of iron in the hepatocytes in the form of ferritin. High liver iron concentrations, in excess of 1000 micrograms/100 mg dry weight, were seen in two patients. Four others given comparable cumulated amounts (18-23 g iron) did not have such high concentrations. Plasma ferritin concentrations were high in eight patients, some with and some without fibrosis. The risk of temporarily high iron deposition in the liver causing damage seemed to be minimal when weighed against the benefit of increased haemoglobin in most of the patients. Intravenous iron treatment merits further evaluation, particularly with the advent of erythropoietin treatment, which requires continuously available iron.

Acral gangrene attributed to calcific azotaemic arteriopathy and the steal effect of an arteriovenous fistula

We describe a young male non-smoker who developed acral gangrene within 4 months of commencing haemodialysis. Amputation of the left hand proximal to the wrist was ultimately required. The onset of peripheral gangrene in this dialysis patient is attributed to calcific azotaemic arteriopathy and the steal effect of an arteriovenous fistula.

Plasma exchange as a treatment for endogenous glycosaminoglycan anticoagulant induced haemorrhage in a patient with myeloma kidney

A 57-year-old man with end-stage renal failure secondary to myeloma kidney developed haemorrhagic complications due to endogenous glycosaminoglycan anticoagulant production. Glycosaminoglycan levels and anticoagulant effect were reduced by plasma exchange and this contributed to control of the haemorrhagic manifestations.

Chemical reactivity of aluminium-based pharmaceutical compounds used as phosphate-binders

Several aluminium-containing substances, including antacids used as phosphate-binders in treating renal failure, have been analysed in-vitro under different pH conditions for the release of Al3+ ions and for binding of phosphate. Control experiments on different forms of pure aluminium hydroxide validated the methods. At pH 2 it was the most amorphous forms which released Al3+ most rapidly. These aluminium ions, available for absorption by the patient, were released from all antacids tested, but no firm phosphate-binding was detected while the pH remained at 2. Phosphate was bound at pH 8, by adsorption onto the surface of aluminium hydroxide. No significant amounts of free Al3+ exist in solution at pH 8, since at that pH aluminium hydroxide is precipitated. The most amorphous forms of this solid were the most efficient phosphate-binders. Alumino-silicate salts require prior exposure to acid to produce free Al3+ before they can act as phosphate-binders, whereas amorphous aluminium hydroxide acts as an efficient phosphate-binder without prior exposure to acid. Chemical principles are employed to show why aluminium release and phosphate-binding are separate and independent processes. Methods are proposed for maximizing the activity of phosphate- binders in-vivo, while minimising aluminium release.

Protracted systemic illness and interstitial nephritis due to minocycline

A severe hypersensitivity-like illness with acute renal failure, lymphadenopathy and skin rash is reported following minocycline treatment in a 16 year old male. Following haemodialysis and steroid therapy his illness remitted, only to recur on withdrawal of the steroids. With further steroid treatment he recovered completely. Lymphocyte function tests, performed in an attempt to positively incriminate minocycline, were inconclusive due to a general suppression of the patient's lymphocytes to in vitro stimulation. Hypersensitivity reactions attributed to minocycline include skin rashes, lymphadenopathy and one previous case of acute interstitial nephritis.

Arterial stiffening and reduced cutaneous hyperaemic response in patients with end-stage renal failure

Superficial dermal vasodilatory capacity and indirect segmental systolic arterial pressure were measured in 10 patients with end-stage renal failure and 13 controls. Laser-Doppler flowmetry was used to measure skin blood flow on the dorsum of the feet prior to and during local skin heating to 40 degrees C. Basal skin blood flow was not significantly different between the two groups (mean 0.8 +/- (SD) 0.3 vs. 0.7 +/- 0.2 U). Peak stimulated flow at 40 degrees C was significantly greater in the controls than in the azotaemic patients (10.0 +/- 3.5 vs. 3.5 +/- 1.6 U, p less than 0.01). Stiffening of the major limb arteries was detected in the majority of the azotaemic patients (10.0 +/- 3.5 vs. 3.5 +/- 1.6 U, p less than 0.01). Stiffening of the major limb arteries was detected in the majority of the azotaemic patients and may have contributed to the reduction in vasodilatory capacity.

Symmetric gangrene of the extremities in late renal failure: a case report and review of the literature

Medical calcification of arteries is common in chronic renal failure. We report on a patient with extensive calcification of the arterial media who developed symmetrical acral gangrene and severe cardiac failure shortly after cadaveric renal transplantation. At necropsy, the medial calcification was found to be accompanied by extensive intimal proliferation and multiple antemortem fractures, some healing by callus formation. Such medial calcification, which is similar to Monckeberg's sclerosis, affected all systemic arteries except the aorta, pulmonary artery and transplanted renal artery. Six years before this terminal illness he had undergone total parathyroidectomy for osteitis fibrosa associated with ruptured tendons. We review previous reports of patients with the syndrome of acral gangrene in azotaemic renal failure and discuss the histopathological features and pathogenesis in relation to the unusual features of our patient.

Recurrent peritonitis caused by Serratia marcescens in a diabetic patient receiving continuous ambulatory peritoneal dialysis

A diabetic patient treated by continuous ambulatory peritoneal dialysis for end-stage renal failure had recurrent peritonitis caused by Serratia marcescens. Thirty-eight isolates of S. marcescens recovered over a 14-month period from peritoneal-dialysis effluent, catheter tips and catheter-exit sites were biotyped and serotyped. The finding that most (90%) of these isolates belonged to the same biotype and serotype suggested that the patient had relapsing infections with the same strain. Similar isolates were recovered from the peritoneal dialysates of another two patients in the same ward, neither of whom developed Serratia-associated peritonitis.

Perthshire pioneer of anti-inflammatory agents (Thomas John Maclagan)

The achievements of Thomas John Maclagan (1838-1903) include the first specific use of salicin to cure acute articular rheumatism. He began salicin treatment in 1874 in Dundee, where he was a medical practitioner from 1869 to 1879. Maclagan was also the resident medical superintendent at Dundee Royal Infirmary from 1864-1866, where he was the first in Scotland to make investigative use of the clinical thermometer during the fever epidemics. From 1879-1903 he maintained a fashionable practice in London. His contributions to medicine and in particular to the development of aspirin, once ranked as equivalent to the achievements of Lister and Simpson, have now largely been forgotten. This account is a tribute to a life rich in individual endeavour, observation and effort before the "teamwork" era began.