Oxysterols are somewhat controversial in science; while some laboratory experiments suggest these steroid molecules may be biologically important, they are present in only trace amounts in the blood, and studies in living animals or humans have not convincingly proven a definitive role.
Therefore, there was great interest when a study published last year in the journal Nature Immunology reported that two oxysterols, known as 15HC and 15KC, were increased more than three-fold in the blood of MS patients, and that these oxysterols could be associated with the development of the disease.
Spurred by those findings, Ingemar Björkhem and colleagues at Sweden's prestigious Karolinska Institutet decided to perform their own analysis of blood samples using a combination of gas chromatography and mass spectrometry, which vaporizes the samples and separates the component parts to allow for a thorough separation of all molecules; thus they could identify 15HC and 15KC levels even at low concentrations.
Despite numerous efforts, though, Björkhem and colleagues failed to find any meaningful 15HC or 15KC oxysterol levels in blood of healthy individuals or MS patients.
To ensure the oxysterols were not being lost or metabolized somewhere along the experimental chain, they also ran blood samples with pre-loaded oxysterols and recovered almost 100 percent of the loaded amount, demonstrating that the protocol was not the problem; any 15HC or 15KC present in the patient samples would have been found.
Björkhem notes that given the conflicting results of recent studies, the potential role of oxysterols in multiple sclerosis needs to be reconsidered.
In a commentary accompanying the new paper by Björkhem's team, William Griffiths and Yuqin Wang of the U.K.'s Swansea University, who were not involved in either study, said they suspect the original research team who reported the oxysterol discovery in 2009 "incorrectly identified [the compounds] in plasma, in which case their data would suggest that some unidentified lipids are increased in the circulation of patients with (MS)."
"It is important that these compounds are now identified," they added.
From the article:
High levels of 15-oxygenated steroids in circulation of patients with Multiple Sclerosis. Fact or fiction? by Ingemar Björkhem et al. Link: http://www.jlr.org/content/early/2010/10/07/jlr.D011072.abstract
Includes companion editorial, Are 15-oxygenated sterols present in the human circulation? by William Griffiths and Yuqin Wang. Link: http://www.jlr.org/content/early/2010/10/18/jlr.E012088.abstractCorresponding Author: Ingemar Björkhem, Karolinska Institute, Sweden
Angela Hopp | EurekAlert!
Zap! Graphene is bad news for bacteria
23.05.2017 | Rice University
Discovery of an alga's 'dictionary of genes' could lead to advances in biofuels, medicine
23.05.2017 | University of California - Los Angeles
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Life Sciences
23.05.2017 | Medical Engineering
23.05.2017 | Life Sciences