Somatosensory evoked potentials and their relation to microstructural damage in patients with multiple sclerosis-A whole brain DTI study.

Introduction: Somatosensory evoked potentials (SSEP) play a pivotal role in the diagnosis and disease monitoring of multiple sclerosis (MS). Delayed latencies are a surrogate for demyelination along the sensory afference. This study aimed to evaluate if SSEP latencies are representative of demyelination of the brain overall, by correlating with cerebral microstructural integrity as measured by Magnetic resonance (MR) diffusion tensor imaging (DTI). Analysis was performed in a hypothesis-free whole brain approach using tract-based spatial statistics (TBSS). Material and methods: A total of 46 patients with MS or clinically isolated syndrome were included in the study. Bilateral SSEPs of the median nerve measuring mean N20 latencies (mN20) and Central Conduction Time (CCT), were acquired. MRI scans were performed at 3T. DTI acquisition was done with a single-shot echoplanar imaging technique with 80 diffusion directions. The FSL software package was used to process the DTI datasets and to calculate maps of fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD). These maps were then further analyzed using the TBSS module. The mean N20 and CCT and the right- and left-sided N20 and CCT were separately correlated to FA, AD, and RD, controlled for age, gender, and EDSS as variables of non-interest. Results: Widespread negative correlations of SSEP latencies with FA (p = 0.0005) and positive correlations with RD (p = 0.0003) were measured in distinct white matter tracts, especially the optic tracts, corpus callosum, and posterior corona radiata. No correlation with AD was found in any white matter tract. Conclusion: Highly significant correlations of FA and RD to SSEPs suggest that their latency is representative of widespread microstructural change, and especially demyelination in patients suffering from MS, reaching beyond the classic somatosensory regions. This points to the usefulness of SSEPs as a non-invasive tool in the evaluation of microstructural damage to the brain.

Enhanced 2,3-butanediol production in fed-batch cultures of free and immobilized Bacillus licheniformis DSM 8785.

2,3-Butanediol (2,3-BD) is a valuable bulk chemical with particular use in industry. 2,3-BD has a potential as solvent and fuel additive, as carrier for pharmaceuticals, or as feedstock for the production of synthetic rubber. Until now, the highest 2,3-BD concentrations were obtained with risk group 2 microorganisms (e.g., Klebsiella oxytoca). In this study, the nonpathogenic bacterium Bacillus licheniformis DSM 8785 was used for 2,3-BD production from glucose. In batch experiments, a maximum 2,3-BD concentration of 72.6 g/L was reached from 180 g/L glucose after 86 h. The yield was 0.42 g/g glucose and the productivity was 0.86 g/(L h). During fed-batch cultivation, 2,3-BD production could be increased up to 144.7 g/L, with a productivity of 1.14 g/(L h). Additionally, repeated batch/fed-batch experiments were conducted using immobilized B. licheniformis in the form of LentiKats®. Results showed a high activity and stability of the immobilizates even after multiple medium replacements, as well as 2,3-BD concentrations, yields, and productivities similar to those obtained with free cells. To our knowledge, these results show the highest 2,3-BD concentration reported so far using a risk group 1 microorganism in general and B. licheniformis in particular. Furthermore, productivity lies in the same range with data reported from risk group 2 strains, which makes B. licheniformis DSM 8785 a suitable candidate for large-scale fermentation processes.

Cosmology favoring extra radiation and sub-eV mass sterile neutrinos as an option.

Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{s} and effective number N{s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{s} is in the sub-eV range.