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Biomedical subjects

M A Mansell

Publications and source records attributed to M A Mansell.

At least 19 recordsLinked to original sources
PubMed1995

Primary hyperoxaluria type 2.

Most cases of primary hyperoxaluria are due to deficiency of hepatic peroxisomal alanine:glyoxylate aminotransferase [i.e. primary hyperoxaluria type 1 (PH1), McKusick 259900] and several hundred examples have been described since the original report in 1925. By contrast, primary hyperoxaluria type 2 (PH2, McKusick 260000) is very rare indeed with only 22 patients recorded since the original description in 1968. PH2 is characterized by hyperoxaluria and L-glyceric aciduria and is caused by deficiency of D-glycerate dehydrogenase/glyoxylate reductase. In comparison with PH1 much less is known about PH2 and considerable uncertainties remain about its frequency, clinical course and optimum management.

Adult↗
PubMed1994

Acute hypernatraemia during bicarbonate-buffered haemodialysis.

Five patients on maintenance haemodialysis were exposed to varying degrees of hypernatric dialysate, leading to acute hypernatraemia (plasma sodium concentrations 158 mmol/l to 179 mmol/l). With the exception of one patient, who developed pulmonary oedema, symptoms were minimal and in each case hypernatraemia was corrected without residual complications. The hypernatric dialysate resulted from a granular and less soluble batch of sodium bicarbonate powder. The extra effort required to dissolve the powder caused CO2 to be shaken out of solution, producing sodium carbonate and raising the pH. Mixing calcium from the 'acid' concentrate with excess carbonate in the 'bicarbonate' concentrate led to rapid precipitation of calcium carbonate on the conductivity monitoring cells. Dialysate conductivity was incorrectly sensed as low by the coated conductivity cells, so that an increasing amount of 'acid' concentrate, with its accompanying electrolytes, was delivered to the patient. When the granular powder was ground to a fine powder, passed through a 125 microns sieve and gently dissolved, the machine operated normally. We recommend that sodium bicarbonate powder is supplied with a sieve size no greater than 125 microns, kept dry to prevent the formation of large crystals, and dissolved gently.

Acute Disease↗
PubMed1994

Risk factors for calculus formation in patients with renal transplants.

OBJECTIVE: To investigate the risk factors for stone formation in patients with functioning renal transplants in whom renal calculi develop. PATIENTS AND METHODS: Renal calculi developed in six of 178 patients with functioning renal transplants under current review, an incidence of 3%. Risk factors for stone formation were investigated in five of these patients and compared with a randomly selected control group of 41 transplant patients with no stone problems. RESULTS: Patients with transplant calculi typically passed smaller volumes of significantly more concentrated and alkaline urine with greater urinary excretion of uric acid (P < 0.05). Urine calcium excretion was also increased. Crystalluria was present in three of five stone formers compared with two of 25 controls. Overall, metabolic abnormalities included hypocitraturia (75%), hyperparathyroidism (36%), hypophosphataemia (24%) and hypercalcaemia (10%). Urinary infection was common (50%) and urinary output of magnesium and phosphate was at the lower end of normal for all patients. CONCLUSION: These results suggest a multifactorial aetiology for stone formation in renal transplant recipients. Approaches to prevention and management are discussed.

Citrates↗
PubMed1991

Combined hepatic and renal transplantation in primary hyperoxaluria type I: clinical report of nine cases.

PURPOSE AND PATIENTS AND METHODS: The purpose of this article is to report the experience of three centers with combined hepatic and renal transplantation for pyridoxine-resistant primary hyperoxaluria type I (alanine:glyoxylate aminotransferase [EC 2.6.1.44] deficiency), with particular emphasis on the selection criteria and timing of the operation. Nine patients with this inherited disease were treated by combined hepatic and renal transplantation. The former replaces the enzyme-deficient organ while the latter replaces the functionally affected organ. RESULTS: One patient with gross systemic oxalosis died in the immediate postoperative period and another died 8 weeks postoperatively of a generalized cytomegalovirus infection, having shown evidence of biochemical correction. One patient with particularly severe osteodystrophy at the time of the operation died 14 months postoperatively from renal failure due to progressive calcium oxalate nephrocalcinosis involving the transplanted kidney, plus thromboembolic disease. He also had very extensive systemic oxalosis. An additional patient with severe osteodystrophy died 9 months postoperatively. One patient developed hyper-rejection of the kidney and died later of gastrointestinal hemorrhage. The four long-term survivors (22 to 38 months) have remained asymptomatic from the standpoint of their renal disease, with resolution of any manifestations of systemic oxalosis that they may have had. They are either employed or continuing their education. CONCLUSIONS: A prolonged period of end-stage renal failure treated by dialysis regimens that are suitable for non-hyperoxaluric renal failure and extensive systemic oxalosis, particularly oxalotic osteodystrophy, are poor prognostic features. We propose that hepatic transplantation should be considered as definitive treatment before end-stage renal failure develops. This should be supplemented by renal transplantation with vigorous pre- and perioperative hemodialysis to deplete the body stores of oxalate. Although some authorities would reserve hepatic transplantation for patients in whom renal transplantation has failed, we suggest that combined liver and kidney transplantation is appropriate in patients who have never had a renal graft. Furthermore, the time has come to consider hepatic transplantation before any irreversible renal damage has occurred in these patients.

Adolescent↗
PubMed1989

The effects of low dose intravenous 99-126 atrial natriuretic factor infusion in patients with chronic renal failure.

The aim was to study the renal and hormonal effects of intravenous 99-126 atrial natriuretic factor (ANF) infusion in a mixed group of patients who had moderate to severe chronic renal failure (CRF) and who were not treated with dialysis. The peak mean plasma level of ANF achieved during the experiment was at the upper limit of an absolute range of basal values previously recorded in a larger group of patients with similar degrees of renal impairment. A significant tissue effect was confirmed by rises in plasma and urinary cyclic guanosine monophosphate, the 'second-messenger' of ANF. ANF infusion increased sodium excretion rate by a mean of 68% compared with a fall of 40% in a placebo group, and significant increases in urinary albumin excretion occurred during the peptide infusion. Thus, the high levels of plasma ANF found in CRF may have a role in the maintenance of sodium balance. In addition, the proteinuric effect may be detrimental to long-term renal function.

Atrial Natriuretic Factor↗
PubMed1989

Treatment of resistant CAPD peritonitis by temporary discontinuation of peritoneal dialysis.

Resistant continuous ambulatory peritoneal dialysis (CAPD) peritonitis (recurrent or persistent infection) is traditionally treated by removal of the CAPD catheter and a period off peritoneal dialysis. In a pilot study we have treated 8 patients with recurrent staphylococcal peritonitis and 3 patients with persistent staphylococcal peritonitis by stopping CAPD for a 2-week period, the CAPD catheter being left in-situ. All 8 patients with recurrent peritonitis and 2 of the 3 patients with persistent peritonitis had resolution of their infection; the third patient required catheter removal to clear the infection. There were no acute problems associated with stopping CAPD, and there was no evidence of loss of peritoneal filtration capacity on restarting CAPD. This novel approach to the treatment of resistant CAPD peritonitis should reduce the number of CAPD catheters replaced and therefore diminish the risks and inconvenience to patients that such replacements entail.

Catheters, Indwelling↗
PubMed1988

Changes in blood acetaldehyde concentrations during acetate haemodialysis.

Hyperacetataemia during acetate haemodialysis has been associated with the development of a variety of unpleasant symptoms, although a direct toxic effect of acetate is hard to prove. Acetaldehyde, which is produced during the metabolism of ethanol to acetate, has various toxic effects including some of those reported during acetate dialysis such as nausea, headache and palpitations. Using a novel, recently developed method we studied blood acetaldehyde concentrations during acetate dialysis in 15 patients and found significant increases in five, with a mean peak value in these patients of 1.36 mumol/l (normal less than 0.4 mumol/l). These five patients also developed high blood acetate concentrations during a subsequent acetate dialysis and showed a significant correlation between blood acetaldehyde and acetate concentrations (r = 0.55, P less than 0.05). Blood acetaldehyde did not change during bicarbonate dialysis in these patients. Our results suggest that significant accumulation of acetaldehyde may occur during acetate dialysis, especially in those patients whose metabolic capacity for acetate is somehow impaired, and that acetaldehyde may contribute to some of the symptoms previously ascribed to 'acetate' intolerance.

Acetaldehyde↗