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Biomedical subjects

M A Mansell

Publications and source records attributed to M A Mansell.

At least 55 records · Page 3Linked to original sources
PubMed1987

Renal transplantation in primary hyperoxaluria.

The increased production and excretion of oxalate in primary hyperoxaluria causes urolithiasis, nephrocalcinosis with renal failure, and systemic oxalosis. Systemic oxalosis occurs late in the course of the disease when there is both oxalate retention and increased oxalate synthesis. The uraemia can be controlled by conventional haemodialysis or peritoneal dialysis but treatment cannot usually keep up with accelerated rate of oxalate production, and dialysed patients develop systemic oxalosis. Most attempts to treat primary hyperoxaluria by renal transplantation have been unsuccessful because of rapid recurrence of nephrocalcinosis with uraemia and systemic oxalosis. Dynamic studies of overall oxalate metabolism in vivo have shown that the renal retention factor becomes a major determinant of oxalosis when the GFR decreases to less than 25 ml min-1 1.73 m-2. We conclude provisionally that vigorous haemodialysis should be begun and transplantation arranged when the GFR reaches this level. Such early transplantation with vigorous perioperative haemodialysis and a large perioperative diuresis of water gives good immediate graft function and oxalate mobilisation from the miscible oxalate pool. The longer term outlook is then influenced more by the factors which determine the success of renal transplantation in non-hyperoxaluric patients.

Glomerular Filtration Rate↗
PubMed1986

Developments in dialysis for acute renal failure.

Although the complication of acute renal failure may occur in all types of medical and surgical patients, many clinicians still treat it using the conservative methods of management first described over 30 years ago. Active management, with early dialysis and adequate nutrition, keeps the patient in the best possible condition so that sufficient time for recovery of renal function is allowed. Many refinements in dialysis technique have occurred and some of these are described below.

Acetates↗
PubMed1985

The effect of pyridoxine on oxalate dynamics in three cases of primary hyperoxaluria (with glycollic aciduria).

We have measured glomerular filtration rate (GFR), extracellular fluid volume (ECF), oxalate distribution volume (OxDV), plasma oxalate concentration (POx.), plasma total clearance of oxalate (PCOx.), oxalate metabolic pool size [(OxDV) X (POx.)], renal clearance of oxalate (RCOx.), oxalate excretion, tissue clearance of oxalate (TCOx.) and tissue oxalate accumulation rate [(TOx.A) = (TCOx.) X (POx.)] in three patients with type I primary hyperoxaluria (hyperoxaluria with hyperglycollic aciduria) when they were taking pyridoxine and after discontinuation of the vitamin. Seven days after stopping pyridoxine the plasma oxalate concentration, oxalate metabolic pool size and the urinary excretion of oxalate had all increased between seven- and eight-fold in two of the patients. The third patient showed no changes on stopping pyridoxine. These results support the view that pyridoxine acts by reducing oxalate biosynthesis in some patients with type I primary hyperoxaluria. The possible biochemical basis for this effect is discussed.

Adult↗
PubMed1985

Correction of anaemia following renal transplantation: serial changes in serum immunoreactive erythropoietin, absolute reticulocyte count and red-cell creatine levels.

Improvement of erythropoiesis following successful human renal transplantation in eight patients was monitored by sequential measurements of haemoglobin, red-cell creatine, absolute reticulocyte count and estimates of serum immunoreactive erythropoietin (siEp). SiEp increased in five patients after transplant, in three cases almost immediately after a return to normal of plasma creatinine. The increase in siEp was followed by a rise in the absolute reticulocyte count and red-cell creatine and finally by an increase in the haemoglobin level. As the haemoglobin approached normal levels a decline in the absolute reticulocyte count preceded a fall in siEp levels. Red-cell creatine also fell, though more gradually than the reticulocyte count. Acute graft rejection (in two patients) was associated with a fall in siEp. Chronic rejection (in one patient) was associated with persistent increases in siEp, reticulocyte count and red-cell creatine; this patient subsequently developed erythrocytosis.

Adult↗
PubMed1985

Rapid correction of red-cell nucleotide abnormalities following successful renal transplantation.

Erythrocyte levels of 5' mono-, di- and triphosphates of adenosine, inosine and guanosine, together with NAD+ (H) and NADP+ (H) were measured before and serially after renal transplantation. The high levels of ATP and guanosine triphosphate (GTP) fell to normal within 3 d of achieving a normal plasma creatinine. The decline in ATP and GTP levels paralleled the fall in plasma creatinine. Acute graft rejection was accompanied by a rise in ATP and GTP, both of which returned rapidly to normal with resolution of the rejection episode. Radiolabelling of red cells confirmed that the metabolism of the existing red-cell population was corrected so that observed changes in nucleotide concentrations were not due to a new cohort of cells.

Adult↗
PubMed1985

Fluid removal by haemofiltration in diuretic resistant cardiac failure.

A 60 year old woman with diuretic resistant cardiac failure was treated with intermittent haemofiltration before tricuspid valve replacement. This technique can remove large quantities of fluid rapidly, thus controlling oedema and allow appropriate fluid replacement. Haemofiltration is thus a simple and safe method of managing unresponsive oedema in cardiac failure sometimes allowing corrective cardiac surgery.

Blood↗
PubMed1985

Primary hyperoxaluria (type I): attempted treatment by combined hepatic and renal transplantation.

A case is reported of a patient with renal failure and developing systemic and renal oxalosis due to pyridoxine-resistant type I primary hyperoxaluria. In spite of vigorous haemodialysis and hydration before and after operation, an allografted cadaveric kidney failed because of oxalate deposits in the transplant. The patient was treated by combined hepatic and renal transplantation. The liver allograft functioned well but the kidney had poor function due to primary acute tubular necrosis aggravated by steroid-associated acute pancreatitis, systemic cytomegalovirus infection and high cyclosporin A levels. The patient died from generalised cytomegalovirus infection. The early course after operation was associated with a reduced rate of oxalate production, which would slow the rate of oxalate deposition in the tissues. The size of the oxalate metabolic pool was also diminished. These observations are compatible with the grafted liver having corrected the metabolic lesion.

Child↗
PubMed1984

Fluid and electrolyte disorders. Sodium.

Because water is freely exchangeable across most cell membranes, its distribution is largely determined by physical factors and by the relative osmolal concentrations of the extracellular and intracellular fluids. As the major extracellular cation, sodium is a principal determinant of the extracellular fluid volume.

Hormones↗
PubMed1983

Pregnancy and cystinuria.

46 pregnancies in patients with cystinuria treated with a high fluid intake alone or in combination with D-penicillamine resulted in 41 normal births. New stones formed in 18 pregnancies, with stone passage early in 4 of them. No patient required stone removal during pregnancy. Other pregnancy-related problems included hypertension and urinary-tract infection, which responded to conventional management. Assiduous maintenance of a sustained high fluid intake is even more important than usual during pregnancy and the puerperium. D-penicillamine appears relatively safe for severe cases, although most patients can be managed without it. With careful medical management stone-forming cystinurics can be safely conducted through pregnancy without increased risks to the mother or fetus.

Birth Weight↗
PubMed1982

Activities of enzymes involved in purine metabolism and some related adenine nucleotide concentrations of leucocytes in renal failure.

We have studied purine metabolism in mononuclear and polymorphonuclear cells from uraemic patients using microradiochemical enzyme assays and high-pressure liquid chromatography. In mononuclear cell lysates the mean activities of adenosine deaminase (EC 3.5.4.4) and 5'-nucleotidase (EC 3.1.3.5) were significantly diminished. The activities of adenylate kinase (EC 2.7.4.3), purine nucleoside phosphorylase (EC 2.4.2.1), adenine phosphoribosyltransferase (EC 2.4.2.7), and hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) were not significantly different in the two groups. The activities of adenosine deaminase and adenine phosphoribosyltransferase were reduced in the polymorphonuclear cell lysates. No clear differences emerged in the concentration of adenine nucleotides in the mononuclear cells. The significance of these changes, which are less marked than those in erythrocytes, is discussed with reference to the immunodeficiency associated with uraemia.

Adenine Nucleotides↗