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Focuses on medical-related issues in Great Britain. Agreement on HIV testing within the British Medical Association; Incidence of coronary disease in people taking strenuous exercise; Management of patients undergoing gastrointestinal operations.

Severe hypernatraemia in a hospital population should be an avoidable problem. We have looked at its causes and incidence over one year and have shown that serious hypernatraemia (serum sodium greater than 160 mmol/l) as a manifestation of severe dehydration is associated with a high morbidity and mortality. Failure to maintain adequate fluid intake, intentional or unintentional, was the most frequent cause. Nursing and medical staff must be made more aware of this problem and encouraged to initiate early treatment of dehydration. [ABSTRACT FROM PUBLISHER]

Analysis of the low levels of catecholamines and metabolites in tissue and biological fluids has necessitated the use of highly sensitive analytical techniques. Earlier procedures utilizing radioenzymatic and immunological assays, gas chromatography or fluorimetry have generally been superseded by highly sensitive and selective chromatographic methods utilizing electrochemical or fluorimetric detection. The development of high-performance liquid chromatography (HPLC) methods for the measurement of plasma metadrenalines and the combination of HPLC with tandem mass spectrometry provides additional procedures with minimum interference from drugs and drug metabolites. This review summarizes the methodology currently available for the measurement of catecholamines and metabolites in plasma and urine, the influence of sample collection protocols and the clinical application of the methods for the biochemical detection of catecholamine-secreting tumours.

Background: Determination of urinary free catecholamine and total (i. e., free plus conjugated) metanephrine excretion is considered the most clinically sensitive biochemical test for pheochromocytoma. In this study, we evaluated new immunoassay methods for the measurement of these analytes for potential drug-based interference., Methods: Urine samples collected from patients on a variety of medications were grouped by specific drug type. The significance of any difference in the free catecholamine or total metanephrine concentrations in the different groups was assessed by one-way ANOVA. A group of patients receiving no medication was included as a control (no analytical interference). Additionally, analytical accuracy, detection limit, and precision were determined., Results: No significant differences were found in the concentrations of free catecholamines or total metanephrines in urine from patients taking the medications investigated and the control group: P = 0.649 (fE), 0.221 (fNE), 0.149 (tM), and 0.170 (tNM). For free catecholamines, intraassay CVs were 4.6-18%; interassay CVs were 10-25%. For total metanephrines, intraassay CVs were 9.6-27%; interassay CVs were 5. 8-22%. Detection limits were 0.009 and 0.027 micromol/L for fE and fNE and 0.119 and 0.346 micromol/L for tM and tNM, respectively., Conclusions: None of the drugs examined in this study interfered in the measurement of free catecholamines or total metanephrines by these immunoassays. The technique is easier to use, requires less equipment, and is more accessible than HPLC. In combination, these assays are suitable as initial screening tests for pheochromocytoma.

Objective: Animal studies suggest that gold compounds impair haem synthesis and increase haem degradation and, as a result, reduce activity of the hepatic haemoproteins cytochromes P-450. The aim of this study was to investigate whether intramuscular gold exerts similar effects in patients with rheumatoid arthritis (RA)., Methods: Urinary porphyrin and precursor excretion, erythrocyte protoporphyrin, and antipyrine clearance, were measured in 6 patients with RA before and 10 weeks after commencement of intramuscular gold., Results: Parameters of haem metabolism were unaffected by gold. While antipyrine clearance was not statistically changed after gold treatment, in 3 of the patients there was an average decrease in antipyrine clearance of 23%., Conclusion: Further studies examining RA patients at different time points are required to investigate further the possibility of reduced hepatic drug metabolising activity during prolonged treatment with gold.

Background: Patients on total parenteral nutrition are known to be at risk of the development of essential fatty acid deficiency, presenting as a syndrome with scaly skin lesions and characterized by low plasma and erythrocyte linoleic acid concentrations. The essential fatty acid status of patients on long-term home parenteral nutrition who do have access to oral feeds has not been studied., Methods: With the use of an isocratic high-performance liquid chromatography method, fatty acids were measured in the erythrocytes and plasma of 25 nonfasting patients on long-term home parenteral nutrition and the findings compared with those of 46 hospital outpatients not on nutrition support and five laboratory staff., Results: Statistically significant differences in the two groups were limited to the erythrocytes. Linoleic acid was significantly lower (25.2 vs 40.7 mumol/10(6) red blood cells, p < .0001) and showed a significant correlation with triceps skinfold thickness (r = .52, p = .013). Palmitoleic and oleic acids were higher in patients than controls (10.8 vs 8.4 mumol/10(6) red blood cells, p = .009; 61.2 vs 51.7 mumol/10(6) red blood cells, p = .003)., Conclusions: Despite IV linoleic acid administration, patients on long-term home parenteral nutrition have low erythrocyte stores of this essential fatty acid. This appears to be related to their low body fat stores. We suggest that they may be using much of the infused linoleic acid as an energy source and therefore are at risk of subclinical essential fatty acid deficiency.

Using a quantitative sensitive HPLC fluorometric assay for the measurement of plasma and urine porphyrins, we have calculated the renal clearance of uro- and coproporphyrin in normal volunteers and in patients with congenital erythropoietic porphyria and hereditary coproporphyria (HCP). In patients with porphyria cutanea tarda (PCT), only uroporphyrin clearance was calculated. Plasma porphyrin concentrations were measured in patients with chronic renal failure (CRF). All our CRF patients on haemodialysis (10) had raised plasma uroporphyrin, 4 had raised plasma heptacarboxyporphyrins and 2 had raised plasma coproporphyrin, unchanged by haemodialysis. CRF patients with raised uroporphyrins and 7-carboxyporphyrins could be distinguished from PCT in patients with normal renal function, by their higher uro/7-carboxyporphyrin ratio (8.0 vs. 1.7). Renal clearance of coproporphyrin was much greater in HCP than in any of the other groups studied. Since coproporphyrin clearance was less than creatinine clearance in most normal subjects, and because 2 patients with CRF had raised plasma coproporphyrin concentrations, we argue that the kidney is probably not a major source of coproporphyrin, as previously reported. Furthermore, the variability and degree of abnormality in plasma porphyrins in CRF would suggest caution in diagnosing chronic porphyria in patients with renal impairment.