Hypophosphatemia following self-treatment for anorexia nervosa.

UNLABELLED: Hypophosphatemia is recognized as a serious complication of hospital treatment for patients with anorexia nervosa but may also occur prior to medical intervention. METHOD: This paper reports a case of severe hypophosphatemia in a patient who consumed large quantities of carbohydrates following a period of dietary restraint. DISCUSSION: The possible mechanisms underlying the hypophosphatemia in this case are discussed and its management is described.

Assessment of iron status in association with excess alcohol consumption.

Biochemical evidence of iron overload (transferrin saturation greater than 60% and/or serum ferritin concentration greater than 1000 micrograms/L) was observed in 16% of patients admitted to an alcohol withdrawal unit. No subjects in an age and sex matched control group showed such biochemical changes. Whilst changes in serum ferritin concentration closely correlated with aspartate aminotransferase activity and could be explained by alcohol induced liver damage, the increased transferrin saturation was not similarly explained. In nine patients withdrawal of alcohol resulted in a decrease in transferrin saturation and serum ferritin, the former due to a reduction in serum iron concentration. In patients with high alcohol intake biochemical measures of iron status may be misleading and a decrease in both transferrin saturation and serum ferritin concentration after withdrawal of alcohol may help to rule out the possible diagnosis of hereditary haemochromatosis.

Serum levels of trace metals in children with atopic eczema.

The hypothesis that atopic eczema is associated with a non-specific decrease in the serum concentration of trace metals was examined by measurement of the levels of zinc, copper and iron in 134 children with atopic eczema and 112 controls. The results failed to confirm the hypothesis. There was no significant difference between patients and controls for the concentrations of serum zinc, iron, iron-binding capacity and albumin. Patients with eczema had a significantly higher copper concentration (median 21.0 mumol/l) than controls (median 17.0 mumol/l), and a significantly lower concentration of ferritin (median 11.9 ng/ml for patients and 16.5 ng/ml for controls). There was a highly significant correlation between the surface area of skin affected by eczema and the concentrations of albumin and orosomucoid.

Effect of albumin and detergent on the reduction of NBT by 1-deoxy-1-morpholinofructose.

The effect of matrix albumin concentration on reduction of NBT by DMF has been investigated together with the effect of cationic additives. Decreased albumin concentration and increased cationic detergent concentration both increased the sensitivity of the assay due to kinetic effects, but addition of a low molecular weight cation had no effect. The reduction of NBT by glycated albumin was not increased in sensitivity by a protein matrix of low concentration. Due to the complexity and poorly understood nature of interaction between DMF and albumin in the reduction of NBT, the authors do not consider DMF to be a suitable primary calibrant for the fructosamine assay.

Acetylcholinesterase activity in rectal biopsies: an assessment of its diagnostic value in Hirschsprung's disease.

Acetylcholinesterase (AChE) activity was measured in rectal suction biopsies from 392 patients investigated for Hirschsprung's disease (HD). Results in HD (2.7-23.7 RU; n = 37) were not clearly differentiated from those in patients without HD (0.6-18.0 RU; n = 355). Sample instability was shown not to be a significant cause of error. From analysis of duplicate biopsies and a consideration of false-negative results, tissue inhomogeneity or incorrect siting of the biopsy appeared likely causes of error. Examination of a number of possible diagnostic decision levels indicated an optimal choice of AChE activity greater than 10 RU with an AChE activity not less than 60% of total cholinesterase activity. At a prevalence of 10%, this decision level resulted in sensitivity of 64.9%, specificity 98.7%, predictive value of positive 85.7%, and predictive value of negative 96.3%. The false positives (n = 4) and false negatives (n = 13) by these criteria were examined to detect possible common features.

Albumin analysis in serum of haemodialysis patients: discrepancies between bromocresol purple, bromocresol green and electroimmunoassay.

The analysis of serum albumin by bromocresol purple (BCP), by bromocresol green (BCG), and by electroimmunoassay (EIA) has been compared in a mixed group of 100 hospital patients. Good agreement between the immunochemical and BCP methods, but a positive bias with the BCG method led to routine use of the BCP method. In a group of 19 paediatric patients on chronic haemodialysis the mean BCP-albumin was found to be lower than the true albumin, as determined by EIA, whereas the positive bias using the BCG method remained. The difference between BCP-albumin and EIA-albumin in the haemodialysis group varied from 0 to -13 g/L (mean -7.1 g/L) but was effectively constant for most patients over a 3-month period. Possible mechanisms and necessary further investigations are discussed.

Low serum zinc in children with atopic eczema.

Serum zinc was measured by atomic absorption spectrophotometry in sixty-five children with atopic eczema and seventy-nine control children. The mean serum zinc of the patients, (11.4 +/- 2.0 mumol/l) was significantly lower than that of the controls (13.7 +/- 2.3 mumol/l, P less than 0.0001). There was no significant correlation between the patients' serum zinc concentration and either the height/weight centile or a subjective assessment of severity and extent of the eczema. Of eleven patients with serum zinc below 10 mumol/l, six had recurrent infections of the skin, a significantly greater proportion than in patients whose serum zinc was 10 mumol/l or above. It is suspected that the decreased plasma zinc concentration in children with eczema is a non-specific consequence of the dermatological disorder, and therefore there is no indication for zinc supplementation.

Zinc supplementation and its effect on taste acuity in children with chronic renal failure.

Diminished taste acuity (hypogeusia) and zinc deficiency have been reported in children on maintenance haemodialysis and with varying degrees of chronic renal failure. We have studied the effect of 6 weeks' zinc supplementation in 20 children with chronic renal impairment using a double-blind crossover trial. Although we achieved significant increases in serum zinc levels no significant improvement in taste acuity could be demonstrated. These studies provide no support for the belief that routine zine supplements are necessary in children with chronic renal failure.

Tyrosine turnover and protein synthesis during parenteral nutrition.

Three patients receiving total parenteral nutrition and one healthy subject receiving 5% glucose were infused for 10 hours with L-(U14C)tyrosine (1.5 microCi/hr). Two alternative assumptions were made regarding the fate of labeled carbon. Total and oxidative fluxes of tyrosine were calculated and these were used to determine rates of protein synthesis and breakdown. Patients showed positive net protein synthesis and oxidation of infused phenylalanine via tyrosine was shown not to be excessive.

Leukocyte amino acid concentrations and their relationship to changes in plasma amino acids.

The leukocyte was selected as an accessible example of an actively metabolizing cell. Plasma and leukocyte amino acids (AA) were studied in a reference group and a group of 12 patients receiving total parenteral nutrition. Differences in the plasma AA were variable; some were higher and others lower in concentration in the infused group. Leukocyte AA concentrations were almost all higher in the infused group and the AA pattern was less altered than in plasma. An explanation of the changes is proposed which helps to clarify the relationship of plasma to cellular AA changes.

Plasma amino acid relationships during parenteral nutrition.

The plasma amino acidfs of 17 patients were studied before and during total parenteral nutrition (TPN). The amino acid (AA) pattern changed similarly for all patients. The AA concentration changes relative to preinfusion (PAER) were the most informative index of change. Two groups of AA were defined, the "branched chain" group (five amino acids) and the "hepatic" group (four amino acids) based on the correlation of PAER values. Comparison of PAER values with the ratio of AA intake to requirement indicated that the requirements of the sick patients were more similar to those of children than those of healthy adults.