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Biomedical subjects

H A Ellis

Publications and source records attributed to H A Ellis.

At least 19 recordsLinked to original sources

Bone aluminium in haemodialysed patients and in rats injected with aluminium chloride: relationship to impaired bone mineralisation.

Iliac bone aluminium was determined by neutron activation analysis in 34 patients with chronic renal failure and in eight control subjects. In 17 patients treated by haemodialysis there was a significant increase in the amount of aluminium (mean +/- SE = 152 +/- 30 ppm bone ash). In eight patients treated by haemodialysis and subsequent renal transplantation, bone aluminium was still significantly increased (92 +/- 4.5 ppm bone ash) but was less than in the haemodialysed patients. In some patients aluminium persisted in bone for many years after successful renal transplantation. There was no relationship between hyperparathyroidism and bone aluminium. Although no statistically significant relationship was found between the mineralisation status of bone and bone aluminium, patients dialysed for the longest periods tended to be those with the highest levels of aluminium, osteomalacia, and dialysis encephalopathy. In 20 rats given daily intraperitoneal injections of aluminium chloride for periods of up to three months, there was accumulation of aluminium in bone (163 +/- 9 ppm ash) to levels comparable to those obtained in the dialysis patients, and after about eight weeks osteomalacia developed. The increased bone aluminium and osteomalacia persisted after injections had been stopped for up to 49 days, although endochondral ossification was restored to normal. As a working hypothesis it is suggested that aluminium retained in the bone of the dialysis patients and the experimental animals interferes with normal mineralisation.

Adult

Serum alkaline phosphatase in azotemic and hemodialysis osteodystrophy: a study of isoenzyme patterns, their correlation with bone histology, and their changes in response to treatment with 1alphaOHD3 and 1,25(OH)2D3.

One hundren seventy-eight azotemic patients, 114 on hemodialysis, had measurements of total serum ALP, and definition of isoenzyme patterns on acrylamide gel electrophoresis. In addition, bone histomorphometry was defined in all of the patients by means of transiliac bone biopsies. Serial estimations over 2 years were carried out on several patients, including some being treated with vitamin D2, 1alphaOHD3, and 1,25(OH)2D3. (1) In both nondialyzed and dialyzed patients, serum ALP showed a significant positive correlation with osteitis fibrosa due to secondary hyperparathyroidism irrespective of the presence or absence of concurrent osteomalacia. Increases in the bone isoenzyme were largely responsible for the rise in total ALP. (2) A higher incidence of osteomalacia (p less than 0.001) was observed in patients on hemodialysis in Newcastle Upon Tyne. In hemodialyzed patients where osteomalacia was accompanied by either no secondary hyperparathyroidism (21 patients) or minimal secondary hyperparathyroidism (14 patients), serum ALP remained within normal limits, giving no indication of the existing osteomalacic bone disease. Isoenzyme studies revealed a high prevalence of the intestinal type and also varied combinations of hepatic, intestinal, and bone types. (3) Good response to vitamin D depended on the presence of significant amounts of the bone isoenzyme. Azotemic osteodystrophy characterized by a raised serum ALP and a prominent bone isoenzyme predicted a good response to vitamin D, and the decrease in serum ALP following vitamin D was the result of a reduction in the bone isoenzyme. Patients with symptomatic dialysis osteomalacic bone disease, accompanied by normal total serum ALP and no elevation of the bone isoenzyme, responded less well.

Alkaline Phosphatase

Evidence for aluminium accumulation in renal failure.

There is increasing evidence that aluminium accumulation in patients with impaired renal function has pathological consequences. The serum aluminium content of 45 patients with chronic renal failure was found to be significantly elevated when compared with normal subjects. A further rise in serum aluminium concentration was seen in patients with chronic renal failure when they were taking aluminium-containing phosphate binding agents. Patients with stable but moderately impaired renal function who are taking aluminium-containing phosphate binders for several years may be at risk from aluminium accumulation and the development of osteomalacia and encephalopathy as seen in patients on intermittent haemodialysis.

Adolescent

Osteomalacic dialysis osteodystrophy: Evidence for a water-borne aetiological agent, probably aluminium.

In patients maintained on regular haemodialysis in Newcastle upon Tyne the development of osteomalacia is substantially reduced when water used to prepare dialysate is deionised. After 1--4 years of dialysis, osteomalacia was evident in 15% of patients on deionised water in 70% of patients on softened water from the same source. The close association of dialysis encephalopathy and osteomalacia suggests a common aetiology. Both diseases occur in centres with a high tap-water aluminium content. Serum-aluminium concentrations were raised in patients undergoing regular haemodialysis in the Northern Region of England. Those using softened water had higher concentrations than those using deionised water. Patients on softened water who had encephalopathy or dementia had serum-aluminium concentrations similar to those of patients using the same water-supplies without symptoms of these diseases, but they had been treated for longer. The evidence that aluminium absorption from dialysate causes osteomalacia and encephalopathy is strong enough to justify the expense of treating water by deionisation, reverse osmosis, or both in centres where tap-water aluminium is high.

Adolescent

Osteomalacic dialysis osteodystrophy: a trial of phosphate-enriched dialysis fluid.

To assess whether phosphate depletion is an aetiological factor in osteomalacic dialysis osteodystrophy we undertook a prospective trial of phosphate-enriched dialysis fluid, in association with oral 1alpha-hydroxycholecalciferol, for this condition. Thirty patients started the trial; of the 27 who completed more than 6 months' treatment, 14 had iliac crest bone biopsies at the beginning and end of the treatment period. Side effects included pruritus, stiffness, and increase in corneal and vascular calcification. Only one patient showed histological improvement of osteomalacia, and eight deteriorated; in seven the osteitis fibrosa worsened. Myopathy showed some improvement in four patients, but became worse in four. This treatment does not seem to have a place in the routine management of non-hypophosphataemic patients on dialysis.

Adolescent

Hemodialysis bone disease: correlation between clinical, histologic, and other findings.

This paper explores in patients with dialysis osteodystrophy the relationship between clinical features and histological, radiological, and biochemical findings. Eighty-five patients treated by hemodialysis for more than 6 months were studied. The following conclusions were drawn: 1) Bone pain in patients on regular hemodialysis is usually a symptom of developing osteomalacia but not of hyperparathyroidism or osteoporosis. 2) Many patients with histological osteomalacia and radiological features of osteomalacia, such as fractures or Looser zones, have no symptoms. 3)In dialysis patients, biochemical and radiological abnormalities are not a reliable means of predicting the presence of osteomalacia, but a raised serum alkaline phosphatase is a good indicator of the presence of osteitis fibrosa. For early detection of osteomalacia, bone biopsy in necessary. 4)A number of our dialysis patients develop an unusual form of osteomalacia characterized by absent or minimal histological osteitis fibrosa, a normal serum alkaline phosphatase, and a high incidence of myopathy and fractures.

Adolescent

Serum ferritin concentration: a reliable guide to iron overload in uremic and hemodialyzed patients.

The inter-relationships between serum ferritin, hemoglobin, serum iron and total body iron stores were studied in 20 patients with chronic renal failure treated conservatively and in 20 patients on regular hemodialysis. There was no relationship between serum iron or transferrin and bone marrow iron deposits, but serum ferritin concentration was a good indicator of increased marrow iron stores. All patients with serum ferritin levels above 300 microgram/l had increased iron stores. Serum ferritin assay is a useful non-invasive technique for detecting iron overload in uremic and hemodialyzed patients.

Adolescent

The need and use of a phosphate-enriched dialysate during regular hemodialysis.

A disabling osteomalacic syndrome seen only during regular hemodialysis is described. Its features include skeletal fractures, pain, suppression of pre-existing hyperparathyroidism, and failure to improve with any of the vitamin-D metabolites. Phosphate depletion may be an important etiological factor but this could not explain all cases. A trial with phosphate-enriched dialysate and 1alphaOHD3 resulted in sustained clinical improvement in 54% of the patients and healing of fractures in 33%. Other etiological factors independent of 1,25(OH)2D3 deficiency and phosphate depletion must be considered. Current, indirect evidence suggests that accumulation of water toxins including aluminium may be important.

Adolescent

Histopathology of renal osteodystrophy with particular reference to the effects of 1alpha-hydroxyvitamin D3 in patients treated by long-term haemodialysis.

(1) The bone histology of 233 non-dialysed and 276 haemodialysed patients with chronic renal failure is reviewed. In non-dialysed patients osteitis fibrosa occurred in 83.7% and osteomalacia in 23.6% of patients. Osteomalacia was not found in the absence of osteitis fibrosa. In haemodialysed patients there was a more variable bone histology, sometimes resembling non-dialysed bone disease, but in general with a greater incidence of osteomalacia, especially with increasing time on dialysis. In some patients there was a predominance of osteomalacia accompanied by no or only mild osteitis fibrosa and the serum alkaline phosphatase was normal. (2) The results of treating twenty-six haemodialysed patients with 1alpha-hydroxyvitamin D3 (1alpha-OHD3) are described. Patients with osteomalacia and minimal or no osteitis fibrosa and a normal serum alkaline phosphatase (Group I) in general failed to respond and it is suggested that 1,25-dihydroxyvitamin D3 deficiency is not the sole factor responsible for the osteomalacia in these patients. In contrast, 1alpha-OHD3 therapy was effective in improving osteitis fibrosa and osteomalacia in some patients with moderate to severe degrees of osteitis fibrosa and osteomalacia (Group IIa) and in improving osteitis fibrosa where this occurred alone (Group IIb).

Adolescent

The effect of 1alpha-hydroxyvitamin D3 in pre-dialysis renal bone disease.

Assessment of 18 azotaemic patients treated with long-term 1alpha-hydroxyvitamin D3 (1alpha-OHD3) confirms the generally favourable effect of this analogue of 1,25-dihydroxyvitamin D3 in azotaemic osteodystrophy. Growing children with radiological rickets respond very well as do adults showing mild hyperparathyroidism with or without osteomalacia. However, patients with severe 'pure' hyperparathyroidism and features of autonomy do not respond well and in such patients 1alpha-OHD3 alone should be avoided. Phosphate restriction and occasionally a sub-total parathyroidectomy may be indicated in these patients.

Adolescent

1,25-dihydroxycholecalciferol in renal osteodystrophy. Epiphysiolysis--anticonvulsant therapy.

Three children with azotaemic renal osteodystrophy were treated with 1,25-dihydroxycholecalciferol (1,25(OH)2D3). All showed clinical, biochemical, and radiological improvement within 6 months of starting treatment. There were no complications. The dose of 1,25(OH)2D3 required was 0-5 microgram per day for 2 children aged 22 and 30 months, and 2 microgram per day for a 15-year-old boy. 2 of the patients were receiving phenobarbitone and phenytoin and in one of them prior treatment with dihydrotachysterol 0-5 mg daily and 6 microgram 1alpha-hydroxycholecalciferol (1alphaOHD3) daily had failed to induce improvement. In one patient, in whom serial iliac bone samples were available, 2 microgram 1,25(OH)2D3 resulted in histological improvement in previously severe osteomalacia. 1,25(OH)2D3 appears to be an effective and safe drug in the treatment of uraemic osteodystrophy.

Adolescent

Effect of renal transplantation on marrow mast cell hyperplasia of chronic renal failure.

Marrow mast cells have been counted in iliac bone from patients with chronic renal failure treated by renal transplantation. Mast cell numbers were initially increased but returned to the normal range in many patients after renal transplantation. Improvement in osteitis fibrosa and osteomalacia after transplant was not clearly related to this diminution in the number of mast cells. The use of prednisone in renal transplant patients may have some effect in reducing the numbers of mast cells. There is no fully acceptable explanation for the increase in marrow mast cells which occurs in chronic renal failure.

Bone Marrow

Quadriceps tendon ruptures in uremia. Treatment with surgery and 1alpha-hydroxycholecalciferol.

Three young patients with chronic renal failure, one on regular hemodialysis, suffered bilateral quadriceps tendon ruptures. All three had uncontrolled, severe osteitis fibrosa. In two, aluminium hydroxide failed to control secondary hyperparathyroidism, while 1alpha-hydroxycholecalciferol (1alphaOHD3) given after the injury resulted in rapid resolution of the hyperparathyroidism. Prevention of tendon ruptures in uremia depends on effective control of secondary hyperparathyroidism. Treatment should involve prompt surgical repair and reversal of the osteitis fibrosa with an effective vitamin D metabolite such as 1alphaOHD3.

Adolescent

Variable response to long-term 1alpha-hydroxycholecalciferol in haemodialysis osteodystrophy.

Ten uraemic patients on regular haemodialysis were treated with 1alpha-hydroxycholecalciferol (1alpha-H.C.C.) for 5 to 14 months. Five patients who had histological osteitis fibrosa with or without osteomalacia responded well, with resolution of musculoskeletal pain, return of raised serum-alkaline-phosphatase concentrations to normal, resolution of radiological subperiosteal erosions, and improvement in histological signs of osteitis fibrosa and osteomalacia. In these patients 1alpha-H.C.C. proved a safe and effective drug. Five other patients did not improve. Characteristically these patients started with moderately severe histological osteomalacia and minimal, if any, osteitis fibrosa. Proximal myopathy was a prominent symptom and serum-alkaline-phosphatase was normal in four of them. Treatment with 1alpha-H.C.C. resulted in early troublesome hypercalcaemia, and repeat bone histology 5--11 months later showed no improvement. It is suggested that in these patients lack of 1,25-dihydroxycholecalciferol may not have been wholly responsible for the observed osteomalacia, hence 1alpha-H.C.C. alone was ineffective. Phosphate depeltion may have been an important contributing factor.

Alkaline Phosphatase

Barbiturate and anticonvulsant treatment in relation to osteomalacia with haemodialysis and renal transplantation.

Among 39 patients treated by regular haemodialysis for four years or more pathological fractures and histological evidence of osteomalacia were significantly more common in those taking barbiturates. Out of 58 transplant recipients surveyed after one year, seven had osteomalacia; four of these had been taking phenobarbitone and phenytoin and one had taken barbiturates alone. Sedatives and other drugs such as phenobarbitone and phenytoin that induce hepatic microsomal enzymes should probably be avoided when possible in patients with chronic renal failure and after transplantation.

Adult