A complex plasma plant sterol locus on mouse chromosome 14 has at least two genes regulating intestinal sterol absorption.

We previously identified two inbred mouse strains, C57BL/6J and CASA/Rk, with different plasma plant sterol levels. An intercross between these strains revealed a broad plasma plant sterol locus on chromosome 14, which peaked at 17 centimorgan (cM) with a maximum logarithm of the odds score of 9.9.

Inclusion of MPA and in a rapid multi-drug LC-tandem mass spectrometric method for simultaneous determination of immunosuppressants.

Background: [corrected] Mycophenolic Acid (MPA) is often co-prescribed as part of a multiple immunosuppressant drug regimen. In this study an established LC-MS/MS method for the measurement of immunosuppressants cyclosporine A, tacrolimus, sirolimus and everolimus was optimized to include MPA without changing the sample pre-treatment and the LC-MS/MS configuration.

Methods: The sample pretreatment for EDTA-plasma was used as for whole blood.

Standardized approach to proteome profiling of human serum based on magnetic bead separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Background: Magnetic bead purification for the analysis of low-abundance proteins in body fluids facilitates the identification of potential new biomarkers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The aims of our study were to establish a proteome fractionation technique and to validate a standardized blood sampling, processing, and storage procedure for proteomic pattern analysis.

Methods: We used magnetic bead separation for proteome profiling of human blood by MALDI-TOF MS (mass range, 1000-10,000 Da) and studied the effects on the quality and reproducibility of the proteome analysis of anticoagulants, blood clotting, time and temperature of sample storage, and the number of freeze-thaw cycles of samples.

Rapid quantification of free and esterified phytosterols in human serum using APPI-LC-MS/MS.

A novel analytical platform based on liquid chromatography and tandem mass spectrometry using atmospheric pressure photoionization was applied for the simultaneous quantification of free and esterified beta-sitosterol, campesterol, brassicasterol, and stigmasterol. The total time for sample pretreatment and analysis could be reduced from approximately 3 h [gas chromatography-mass spectrometry (GC-MS)] to 15 min. The detection limits of the different phytosterols ranged between 0.

Rapid simultaneous quantification of immunosuppressants in transplant patients by turbulent flow chromatography combined with tandem mass spectrometry.

Background: Immunosuppressant therapeutic drug monitoring (TDM) is an important requirement in the management of post-transplant patients. Our aim was to develop and evaluate a robust high-throughput method using turbulent flow chromatography (TFC) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous quantification of cyclosporin A (CsA), tacrolimus (FK 506) and sirolimus.

Methods: A total of 1483 EDTA-blood pre-dosage samples from 147 kidney, 67 liver, 15 kidney/pancreas, and 48 bone marrow recipients were collected.