Development of a Chiral Supercritical Fluid Chromatography-Tandem Mass Spectrometry and Reversed-Phase Liquid Chromatography-Tandem Mass Spectrometry Platform for the Quantitative Metabolic Profiling of Octadecanoid Oxylipins

Octadecanoids are broadly defined as oxylipins (i.e., lipid mediators) derived from 18-carbon fatty acids. In contrast to the well-studied eicosanoids, there is a lack of analytical methods for octadecanoids, hampering further investigations in the field. We developed an integrated workflow combining chiral separation by supercritical fluid chromatography (SFC) and reversed-phase liquid chromatography (LC) coupled to tandem mass spectrometry detection for quantification of a broad panel of octadecanoids. The platform includes 70 custom-synthesized analytical and internal standards to extend the coverage of the octadecanoid synthetic pathways. A total of 103 octadecanoids could be separated by chiral SFC and complex enantioseparations could be performed in <13 min, while the achiral LC method separated 67 octadecanoids in 13.5 min. The LC method provided a robust complementary approach with greater sensitivity relative to the SFC method. Both methods were validated in solvent and surrogate matrix in terms of linearity, lower limits of quantification (LLOQ), recovery, accuracy, precision, and matrix effects. Instrumental linearity was good for both methods (R² > 0.995) and LLOQ ranged from 0.03 to 6.00 ng/mL for SFC and 0.01 to 1.25 ng/mL for LC. The average accuracy in the solvent and surrogate matrix ranged from 89 to 109% in SFC and from 106 to 220% in LC, whereas coefficients of variation (CV) were <14% (at medium and high concentrations) and 26% (at low concentrations). Validation in the surrogate matrix showed negligible matrix effects (<16% for all analytes), and average recoveries ranged from 71 to 83%. The combined methods provide a platform to investigate the biological activity of octadecanoids and expand our understanding of these little-studied compounds.

[Problems in early diagnosis of malignancies in general medicine]

If specialists expect general practitioners to carry out extensive investigations serving early detection of diseases they don't consider how limited in that respect the possibilities of general practitioners are. In general, practice however the early detection of malignancies is satisfactory if the doctor makes use of the short time available the best possible.

[Acute erythromelalgia with hypertension in a 5-year old boy]

BACKGROUND

Burning pain of red and warm hands and/or feet are the classical symptoms of erythromelalgia.

CASE REPORT

We describe the symptoms of acute idiopathic erythromelalgia and arterial hypertension in a five-year-old boy. Five days after a gastroenteritis the patient developed burning hands and feet in combination with arterial hypertension. Typically continuous cooling of all affected limbs was necessary to relieve the pain. Drug therapy with sodium nitroprusside only relieved the pain and dropped the blood pressure temporarily. Five weeks after onset of the disease all symptoms disappeared and the patient is still free of complaints (follow up period: 2 years). In the view of the presented case we discuss the differential diagnoses as well as therapeutical options.