Red cell exchange transfusion as a rescue therapy for tacrolimus toxicity in a paediatric renal transplant.

Tacrolimus is a widely used macrolide immunosuppressant that has a narrow therapeutic index and potential side effects including neurotoxicity. A 20-month-old boy with kidney disease secondary to prune belly syndrome variant, managed on peritoneal dialysis, received a deceased donor transplant. Standard immunosuppression was used.

Testosterone assays: guidelines for the provision of a clinical biochemistry service.

Approximately one year after the devolution of testosterone assays from the SAS, the Analytical Methods Working Party of the Association of Clinical Biochemists set up a working party to investigate the performance of the assays, to survey the available methodology and to give guidance on the factors that influence the assay. This document represents a summary of the deliberations of the group and forms one of a series of similar reports.

Does melatonin deficiency cause the enlarged genitalia of the fragile-X syndrome?

Melatonin profiles were studied in five males with cytogenetic and clinical features of the fragile-X syndrome including megalo-orchidia and macrogenitosomia. In comparison with age-matched normal controls, the fragile-X group showed lower melatonin values and a significant impairment of the nocturnal rise in this hormone. Melatonin deficiency may thus be responsible for some of the phenotypic features of this disorder.

Bartter's syndrome--observations on the pathophysiology.

The pathophysiology of Bartter's syndrome affecting seven adults has been investigated. (1) Saralasin infusion caused a fall in blood pressure in all patients, suggesting that angiotensin was contributing to the maintenance of blood pressure. (2) Following a water load, urinary chloride concentrations and osmolality were both low.