Hypercalciuria and ultrasound abnormalities in children with cystinosis.

We noted microscopic haematuria in children with cystinosis. To investigate this we studied urinary calcium excretion and undertook renal ultrasound scans. Most patients had elevated urinary calcium excretion and all had abnormal appearances on ultrasound scan, ranging from increased cortical echogenicity only to those with increased cortical and medullary echogenicity.

Assessment of retinol-binding protein excretion in normal children.

Retinol-binding protein (RBP) is a low molecular weight protein freely filtered at the glomerulus. The fractional tubular reabsorption of RBP is 99.97% and increased excretion is therefore a sensitive marker of tubular dysfunction.

Acetazolamide and high altitude diseases.

Acetazolamide is a useful prophylactic for acute mountain sickness causing marked reduction in headache, nausea, vomiting, weakness, etc. Improvements correlate with increased arterial oxygen concentrations, reduction in proteinuria and peripheral oedema and other objective measures of acute mountain sickness. Evidence that Acetazolamide is beneficial for pulmonary oedema or cerebral oedema is scanty because of the lower frequency of these severe forms of mountain sickness.