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Biomedical subjects

M K Ward

Publications and source records attributed to M K Ward.

At least 109 records · Page 6Linked to original sources

Accumulation of silicone elastomer in regular dialysis.

A retrospective autopsy study of 78 patients treated by some form of dialysis for chronic renal failure in Newcastle 1964-1981 showed that: 1) Particles resembling silicone elastomer were present in 48 per cent of 61 patients haemodialysed with the use of silicone rubber pump inserts but in none of the 11 treated by haemodialysis with other pump inserts or of the six treated by peritoneal dialysis alone; 2) The prevalence of these particles and their density increased with time on haemodialysis; 3) There was little evidence of a tissue reaction to the particles and no association between their presence and histological evidence of liver disease; 4) There was a higher incidence of clinical and biochemical evidence of liver disease in patients with silicone deposits than in those without. Although there are other possible explanations for this higher incidence of hepatic dysfunction it would be safer to assume that silicone particle spallation is not innocuous.

Humans↗

Intravenous methylprednisolone at the time of renal transplantation.

Ninety-five consecutive transplants performed prior to the introduction of methylprednisolone bolus at transplantation were compared to 136 consecutive transplants performed after the policy change. No difference was found in the incidence of reversible or irreversible rejection in the two groups. The treated group were exposed to a higher total dose of steroid than the non-treated group. Routine bolus methylprednisolone therapy at transplantation is not recommended.

Adult↗

Continuous ambulatory peritoneal dialysis: three years' experience.

We review the experience of the Renal Unit at Newcastle upon Tyne over the three years 1979-1981, during which 122 patients with chronic renal failure were treated by continuous ambulatory peritoneal dialysis (CAPD). Advantages of the technique included wide acceptability to a cross-section of patients reaching the renal unit, including the elderly and diabetics. Patients who experienced both techniques preferred CAPD to haemodialysis because of the greater freedom and sense of well-being. Patient survival was 94 per cent at two years and rehabilitation was as good as could be expected for the age and primary medical complications of the patients. Control of plasma potassium and phosphate was easier than with haemodialysis. Renal osteodystrophy responded well to a combination of CAPD and alfacalcidol therapy over the two year period for which we have performed serial bone biopsies. Serum aluminium was slightly raised as a result of consumption of phosphate binders and presumed uptake from dialysis fluid but no aluminium related disease has yet been encountered. Anaemia was partly corrected by CAPD with haemoglobin rising to about 10 g/dl on average. CAPD was less costly than home haemodialysis over the first three years and has been adopted as our standard treatment for patients who can expect an early transplant. Disadvantages were persisting problems with peritonitis which still occurred at an incidence of one attack per 39 patient weeks over the last two years, and an actuarial success rate for the technique of only 63 per cent at two years. Twenty patients developed hernias. Weight gain was common and occasionally gross. There was a significant rise in serum cholesterol. The arrival of CAPD has allowed us to increase the intake to our renal failure programme by 50 per cent. However, continued expansion of the technique demands advances in prevention of peritonitis, adequate facilities for admission and particularly an expanding hospital haemodialysis programme to accept the less successful patients from CAPD.

Adolescent↗

Haemodialyser reuse: impact on function and biocompatibility.

The functional performance (clearance of small molecules, ultrafiltration and blood loss) and biocompatibility (haemodialysis leucopenia) has been studied for disposable flat plate and hollow fibre haemodialysers utilizing Cuprophan membranes on their first use, and compared with that obtained when reusing by a manual and automated technique. The results obtained relating to functional performance remain unchanged with the exception of blood loss which shows an increase compared with first use. Biocompatibility is modified on reuse but only if the membrane has not been exposed to a rinsing process using sodium hypochlorite.

Humans↗

Osteomalacia in patients with chronic renal failure before dialysis or transplantation.

The case records of 327 patients who underwent bone biopsy in late or terminal renal failure, before any form of dialysis or transplantation, were examined for clues to the aetiology of renal osteomalacia and its manifestations. Fifty four per cent of the biopsies showed pure osteitis fibrosa, 34 per cent osteomalacia with osteitis fibrosa and 12 per cent showed neither abnormality. Osteomalacia was strongly associated with chronic pyelonephritis and obstructive uropathy as primary renal disease. In two matched groups of 100 each, and within the major primary diseases, it was associated with acidosis, hypocalcaemia and normophosphataemia (as opposed to hyperphosphataemia). There was no association with known length or uraemia and only a weak and inconsistent relationship with severity of uraemia. In the few patients studied, there was no relationship between osteomalacia and serum 25-hydroxycholecalciferol level. In contrast to the state of patients treated by haemodialysis, osteomalacia in this undialysed group was manifested by a higher level of serum alkaline phosphatase than pure osteitis fibrosa, serum iPTH did not differ between the groups, there was no predominance of symptoms in one group, other than proximal myopathy which had a weak association with osteomalacia, and Looser zones were more common than complete fractures. Our study shows that osteomalacia has different manifestations, and probably different causes, before and after the start of haemodialysis. These two stages of renal failure should be clearly distinguished in reports of renal bone disease.

Acidosis↗

[Blood phosphate and calcium metabolism in bicarbonate dialysis of chronic stable hemodialysis patients].

Leucocyte count, blood pH and gases, plasma concentrations of total and ionised calcium, of phosphate and PTH were studied in 11 stable patients on chronic haemodialysis alternatively, the sequence being randomised, during acetate (AHD) and bicarbonate (BHD). Initial leucopenia and its subsequent correction were comparable with both dialysis types whereas pO2 and pCO2 transitory decreased only in AHD so that the mechanism of hypoxemia with AHD does not seem to be related to the pulmonary leucostatis but rather to the reflex hypoventilation secondary to the decrease of pCO2 into the acetate dialysis. As regards the bone metabolism, no difference was observed between HDA and HDB considering the increase of total and ionised calcium, the decrease of plasma phosphate and the absence of decrease of PTH, the initial levels of which being however only slightly elevated. However blood pH was significantly (but slightly) higher before the subsequent dialysis in the case of BHD. This more sustained correction of acidosis would be the only theoretical advantage of BHD for the prevention of bone demineralisation.

Acetates↗

Shunt nephritis: report of two cases and review of the literature.

We report two cases of glomerulonephritis associated with infection of cerebrospinal fluid shunts inserted for the treatment of hydrocephalus and comment an another 70 cases reported in the world literature. Although infection of CSF shunts is common, the development of glomerulonephritis is rare. Non-pathogenic bacteria are the commonest infecting organisms. Antibiotics are generally ineffective in eradicating the infection and the glomerulonephritis, but removal of the shunt is usually, though not always, associated with complete resolution of the renal disease.

Adult↗

Osteomalacia in chronic renal failure before dialysis.

Bone biopsies taken from 327 patients before the start of dialysis have been correlated with clinical and biochemical findings to test various theories about the aetiology of osteomalacia. Two groups of patients, 100 with osteomalacia and 100 with pure osteitis fibrosa, have been compared in detail. Osteomalacia is associated with chronic pyelonephritis or obstruction as primary renal disease, and with acidosis, hypocalcaemia and normophosphataemia (as opposed to hyperphosphataemia). We have found no association between osteomalacia and known duration or severity of uraemia and in a small series of observations we have not confirmed previous reports of a close association between osteomalacia and depressed plasma 25(OH) cholecalciferol values.

Acidosis↗

Peritonitis in continuous ambulatory peritoneal dialysis. Laboratory and clinical studies.

During a three year period, 1979-81, 82 patients were treated by continuous ambulatory peritoneal dialysis (CAPD). The incidence of peritonitis was reduced significantly during the three years from one episode per 20 patient-weeks to one episode every 37 patient-weeks. 83% of the 136 episodes of peritonitis were treated successfully by antibiotic therapy alone. 62% of the total episodes were managed successfully with intraperitoneal cefuroxime. in 13 (16%) patients, CAPD failed because of peritonitis. Hospital admission for peritonitis has been reduced to a mean of 4.3 days per patient per year of CAPD. Fron January to September, 1982, Clostridium-difficile colitis developed in 13 patients. This complication was associated with considerable mortality and morbidity and has prompted a change in antibiotic policy. Patients with peritonitis are now given intraperitoneal netilmicin and intravenous vancomycin. Peritonitis remains the main complication of CAPD, but can be minimised by development of adequate facilities for performing CAPD.

Adolescent↗

A method for the routine determination of aluminium in serum and water by flameless atomic absorption spectrometry.

A simple but reliable method for the routine determination of aluminium in serum and water by flameless atomic absorption spectrometry is described. No preparatory procedures are required for water samples, although serum is mixed with a wetting agent (Triton X-100) to allow complete combustion of the samples and to improve analytical precision. Precautions to prevent contamination during sample handling are discussed and instrumental parameters are defined. The method has a sensitivity of 35.5 pg and detection limits of 2.3 micrograms Al/l for serum and 1.3 micrograms Al/l for water. The method was used to determine the aluminium concentration in serum of 46 normal subjects. The mean aluminium content was 7.3 micrograms/l (range 2--15 micrograms/l.

Adolescent↗

Effect of aluminium hydroxide on serum ionised calcium, immunoreactive parathyroid hormone, and aluminium in chronic renal failure.

According to the Bricker-Slatopolsky theory, secretion of parathyroid hormone (PTH) is switched on in chronic renal failure by hypocalcaemia due to phosphate retention. In an attempt to reverse this process 20 patients in preterminal renal failure (plasma creatinine 569 +/- 195 mumol/l) were given aluminium hydroxide, 3.8 g daily. They were studied for four weeks and all measurements were made at the start and weekly, except measurements of serum aluminium concentration, which were made at the start and at the end of the fourth week. Mean serum phosphate fell from 1.89 to 1.47 mmol/l (5.9 to 4.6 mg/100), mean serum calcium rose from 2.07 to 2.24 mmol/l (8.3 to 9.0 mg/100 ml), and serum ionised calcium rose from 1.07 to 1.20 mmol/l (4.3 to 4.8 mg/100 ml), but serum immunoreactive PTH did not fall. Thirteen patients had initial serum immunoreactive PTH concentrations at or near to normal and 11 were taking beta-blockers but even in those with neither explanation, PTH concentrations did not fall. Serum aluminium concentrations rose from 0.4 to 1.02 mumol/l (10.9 to 27.4 microgram/l). Aluminium hydroxide corrects serum phosphate, total calcium, and ionised calcium at the price of a rise in serum aluminium concentration; in this study it did not affect serum immunoreactive PTH. The Bricker-Slatopolsky theory still needs verification in studies of patients with chronic renal failure.

Aluminum↗

Superiority of B locus matching over other HLA matching in renal graft survival.

Graft survival after 348 consecutive first cadaver-donor renal transplants was significantly improved by HLA matching when recipients who had received pretransplant blood transfusions were matched with their kidney donor for two HLA-B locus antigens. No other type of HLA matching significantly improved graft survival in transfused recipients nor did any type of HLA matching in non-transfused recipients. Matching for one HLA-DR antigen had no benefit in transfused recipients. Only two patients received kidneys matched for both DR antigens and only two of those in whom DR matching had been performed had not been transfused. These results indicate that pretransplant blood transfusion and selection of graft recipients predominantly on the basis of HLA-B matching has significantly reduced the renal graft rejection rate in Newcastle upon Tyne over two years. Thus, HLA-B antigen matching should be adopted as the main criterion for kidney sharing between transplant centres.

Adult↗

The natural history of chronic pyelonephritis in the adult.

One hundred and thirty patients with primary chronic pyelonephritis diagnosed radiologically or by nephrectomy, 84 with unilateral and 46 with bilateral disease, have been followed for six to 240 months. The clinical and radiological features of the disease at presentation, together with its influence on pregnancy, have been analysed. Serial observations of bacteriuria, blood pressure and renal function have been made during follow up and the intravenous urogram (IVU) has been repeated after five years in most patients. Although the disease probably starts in early childhood it often presents to the nephrologist in young adults, mainly women, as symptomatic urinary tract infection, hypertension, renal insufficiency or a combination of these features. Though associated with increased morbidity in pregnancy it does not usually interfere with fertility and in this series it did not cause increased fetal loss. Repeated urinary tract infections and hypertension are common events. Proteinuria is usually minimal and when present is associated with hypertension. The disease in most patients with unilateral disease runs a benign course; a poorer prognosis is associated with bilateral disease, hypertension and proteinuria. Since we found no association between frequent urinary infections and declining renal function we suggest that only symptomatic urinary infection should be treated in adults with chronic pyelonephritis.

Adolescent↗