Determination of N-acetylation phenotype using caffeine as a metabolic probe and high-performance liquid chromatography with either ultraviolet detection or electrospray mass spectrometry.

A rapid, sensitive method using liquid chromatography-electrospray mass spectrometry (LC-ES-MS) was developed and evaluated for the simultaneous quantitative determination of caffeine metabolites 1U, 1X and AAMU in human urine. This method involved a simple dilution of urine samples. The chromatographic separation was achieved on a C18 reversed-phase column using a gradient of acetonitrile in 2 mM, pH 3.

Prospective study of toxoplasma reactivation by polymerase chain reaction in allogeneic stem-cell transplant recipients.

Toxoplasmosis is a rare but life-threatening complication of allogeneic stem-cell transplantation. Polymerase chain reaction (PCR) offers the possibility to make the diagnosis earlier than conventional techniques, and is then expected to improve the prognosis. We undertook a prospective screening using a competitive PCR in blood in 32 stem-cell transplant recipients.