[Patient with West Nile fever in the Netherlands]. / Een patiënte met West-Nijl-koorts in Nederland.

A 45-year-old patient was admitted with high fever and inadequate behaviour. She had recently stayed in Israel. Extensive investigation suggested a viral infection, but the cause was not established. Her partner suggested the possibility of West Nile virus infection, based upon information he had found on the Internet. Serology was performed and specific IgM and IgG antibodies were demonstrated, but a paired serum sample was not available. The patient recovered spontaneously. The West Nile virus is endemic in Israel, Africa, Asia and the Balkans. It is transmitted by mosquitoes. The incubation time is 1-3 weeks. The disease is characterised by fever, malaise, maculopapular exanthema and lymphadenopathy. Complications are encephalitis, pancreatitis, hepatitis and myocarditis. However, these symptoms are present in less than 5% of all infections. A full-blown encephalitis has a mortality rate of 50%. There is no specific therapy, but prevention by means of controlling the mosquito population is feasible. The diagnosis is made by the detection of West Nile virus-specific IgM antibodies in serum or cerebrospinal fluid. However, in the acute stage viral RNA detection by a polymerase chain reaction in the serum is also possible.

High-performance liquid-chromatographic simultaneous determination of commonly used tricyclic antidepressants.

We report a method for simultaneous measurement of five commonly used tricyclic antidepressant drugs (doxepin, desipramine, nortriptyline, imipramine, and amitriptyline) in serum by paired-ion high-performance liquid chromatography, with use of a reversed-phase column and ultraviolet detection at 254 nm. The drugs are extracted from 2 ml of serum at pH 14 into hexane/isoamyl alcohol (99/1 by vol) and re-extracted into 200 microliter of 0.1 mol/liter HCI. An aliquot of the aqueous acid phase is chromatographed with use of a methanol/acetonitrile/water (41/15/44) solvent system, containing 5 mmol of pentanesulfonic acid per liter of phosphate buffer (0.1 mol/liter, pH 6.5), at a flow rate of 1,5 ml/min. Analytical recoveries of the drugs from serum increase with increasing concentration, from 62% at 25 microgram/liter to 93% at 300 microgram/liter. Linear response is observed for drug concentrations up to 1500 microgram/liter and the detection limit is 2-3 microgram/liter. Within-run precision ranges from 1.4 to 2.9% and day-to-day precision from 1.7 to 7%, depending on the specific drug. The entire procedure can be completed within 45 min and is well adapted to the routine clinical laboratory. Of 48 common basic and several neutral drugs tested for possible interferences, only three benzodiazepines, three phenothiazines, and three antihistamines interfere with the assay of doxepin, desipramine, and nortriptyline, respectively.