Abstract
Elevated urinary levels of modified nucleosides, especially pseudouridine (Ψ), have been observed in patients with a variety of malignant neoplasms. In this report, the urinary Ψ levels were estimated by high performance liquid chromatography in 93 patients with brain tumours and in 40 age and sex matched controls. The Y levels were found to be excreted in equal amounts in the control and the tumour groups. There was no significant difference in Y when patients with malignant diseases were compared with those with benign tumours. Following therapy, the Y levels remained unchanged when compared to the controls and their preoperative values. It is concluded that urinary Y concentration is not a useful marker for brain tumours.