Merck

Diagnostic use of cerebral and extracerebral oxysterols.

Clinical chemistry and laboratory medicine (2004-04-06)
Valerio Leoni, Thomas Masterman, Fariba S Mousavi, Bengt Wretlind, Lars-Olof Wahlund, Ulf Diczfalusy, Jan Hillert, Ingemar Björkhem
ABSTRACT

24S-Hydroxycholesterol (24OHC) and 27-hydroxycholesterol (27OHC) are two structurally similar oxysterols of different origins--the former almost exclusively formed in the brain and the latter formed to a lesser extent in the brain than in most other organs. HYPOTHESIS TO BE TESTED: Neuronal damage and/or demyelination causes increased flux of 24OHC from the brain into the cerebrospinal fluid (CSF), whereas a defect blood-brain barrier causes increased flux of 27OHC from the circulation into the CSF. Isotope dilution-mass spectrometry was used to assay the two oxysterols in CSF and plasma from more than 250 patients with different neurological and geriatric diseases. The CSF-levels of the two oxysterols were much more affected by the different diseases than the plasma levels. Patients with active demyelinating diseases had increased levels of 24OHC in CSF with a relatively high 24OHC/27OHC ratio. Patients with meningitis in general had high levels of both steroids with a low 24OHC/27OHC ratio. Patients with Alzheimer's disease had slightly increased levels of 24OHC in CSF with less increase in 27OHC. Patients with multiple sclerosis had a tendency to have higher levels of 24OHC during active periods with a high 24OHC/ 27OHC ratio. Measurements of the two oxysterols in CSF and plasma may add significantly to existing biochemical methods for evaluation of neurological diseases.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
L-Asparagine, ≥98% (HPLC)
Sigma-Aldrich
DL-Homocysteine, ≥95% (titration)
Sigma-Aldrich
Adenosine 3′,5′-cyclic monophosphate, ≥98.5% (HPLC), powder
Sigma-Aldrich
L-Asparagine, BioReagent, suitable for cell culture, suitable for insect cell culture
Sigma-Aldrich
Urea, ACS reagent, 99.0-100.5%
Sigma-Aldrich
Urea, BioXtra, pH 7.5-9.5 (20 °C, 5 M in H2O)
Sigma-Aldrich
(−)-Epinephrine
Sigma-Aldrich
L-Serine, ReagentPlus®, ≥99% (HPLC)
Sigma-Aldrich
Urea, powder, BioReagent, for molecular biology, suitable for cell culture
Sigma-Aldrich
Urea, meets USP testing specifications
Sigma-Aldrich
L-Glutathione reduced, ≥98.0%
Sigma-Aldrich
L-Cysteine, from non-animal source, BioReagent, suitable for cell culture, ≥98%
Sigma-Aldrich
L-Glutathione reduced, BioXtra, ≥98.0%
Sigma-Aldrich
L-2-Aminobutyric acid, BioReagent, suitable for cell culture
Sigma-Aldrich
L-2-Aminobutyric acid, ≥99% (titration)
Sigma-Aldrich
L-Serine, BioUltra, ≥99.5% (NT)
Sigma-Aldrich
Urea, BioUltra, for molecular biology, ≥99% (T)
Sigma-Aldrich
L-Glutamine, BioUltra, ≥99.5% (NT)
Titanium, IRMM®, certified reference material, 0.1 mm foil
Sigma-Aldrich
L-Phenylalanine, from non-animal source, meets EP, JP, USP testing specifications, suitable for cell culture, 98.5-101.0%
Sigma-Aldrich
L-Glutathione reduced, suitable for cell culture, BioReagent, ≥98.0%, powder
Sigma-Aldrich
L-Phenylalanine, reagent grade, ≥98%
Sigma-Aldrich
Fumaric acid, tested according to USP/NF
Sigma-Aldrich
L-Cysteine, BioUltra, ≥98.5% (RT)
Sigma-Aldrich
Bismuth, granular, ≥99.99% trace metals basis
Sigma-Aldrich
Zinc, granular, 30-100 mesh, 99%
Sigma-Aldrich
Fumaric acid, ≥99.0% (T)
Sigma-Aldrich
L-Glutamic acid, BioUltra, ≥99.5% (NT)
Sigma-Aldrich
1-Methyl-L-histidine, ≥98.0% (TLC)
Sigma-Aldrich
(R)-3-Hydroxybutyric acid, ≥98.0% (T)