N-acetylaspartic acid in cerebrospinal fluid of multiple sclerosis patients determined by gas-chromatography-mass spectrometry

Background: Axonal degeneration is considered to play a major role in the development of clinical disability in multiple sclerosis (MS). N-AcetylAspartic Acid (NAA) is a neuron-specific marker constantly identified in MR-spectroscopy studies of the normal and MS brain. To our knowledge there are no studies available that evaluated NAA in cerebrospinal fluid (CSF) as a possible marker for disease severity. Objective: To evaluate CSF concentrations of NAA in MS in relation to disease phenotype, clinical measures of disability and MRI markers of disease burden. Methods: NAA concentrations were determined in CSF of 46 patients with MS (26 relapsing remitting (RRMS), 12 secondary progressive (SPMS) and 8 primary progressive (PPMS)). Prior to lumbar puncture, MS-patients underwent MRI and clinical examination, including the Expanded Disability Status Scale (EDSS) and the MS Functional Composite (MSFC). Additionally, CSF concentrations of NAA were determined in 12 patients with other neurological diseases (OND). Results: Median CSF NAA concentration was 0.74 (IQR: 0.59-0.94) in RRMS , 0.54 (IQR: 0.35-0.73) in SPMS and 0.83 μmol/l (IQR: 0.56-1.03) in PPMS patients. SPMS patients had a significantly lower NAA concentration than RRMS patients. NAA concentrations correlated with EDSS (r = )0.37, p = 0.016), MSFC (r = 0.41, p = 0.010), normalised brain volume (r = 0.49, p = 0.001), T2 lesion load (r = )0.35, p = 0.021) and black hole lesion load (r = )0.47, p = 0.002). No differences were observed between OND (median: 0.57 IQR: 0.28-0.73) and MS patients. Conclusions: CSF NAA concentration in MS patients is related to clinical performance and MRI measures of disease burden and may therefore be an important neuron specific marker of disease severity and possibly progression

A New Human Somatic Stem Cell from Placental Cord Blood with Intrinsic Pluripotent Differentiation Potential

Here a new, intrinsically pluripotent, CD45-negative population from human cord blood, termed unrestricted somatic stem cells (USSCs) is described. This rare population grows adherently and can be expanded to 1015 cells without losing pluripotency. In vitro USSCs showed homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, and hematopoietic and neural cells including astrocytes and neurons that express neurofilament, sodium channel protein, and various neurotransmitter phenotypes. Stereotactic implantation of USSCs into intact adult rat brain revealed that human Tau-positive cells persisted for up to 3 mo and showed migratory activity and a typical neuron-like morphology. In vivo differentiation of USSCs along mesodermal and endodermal pathways was demonstrated in animal models. Bony reconstitution was observed after transplantation of USSC-loaded calcium phosphate cylinders in nude rat femurs. Chondrogenesis occurred after transplanting cell-loaded gelfoam sponges into nude mice. Transplantation of USSCs in a noninjury model, the preimmune fetal sheep, resulted in up to 5% human hematopoietic engraftment. More than 20% albumin-producing human parenchymal hepatic cells with absence of cell fusion and substantial numbers of human cardiomyocytes in both atria and ventricles of the sheep heart were detected many months after USSC transplantation. No tumor formation was observed in any of these animals

Association of Retinal and Macular Damage with Brain Atrophy in Multiple Sclerosis

Neuroaxonal degeneration in the central nervous system contributes substantially to the long term disability in multiple sclerosis (MS) patients. However, in vivo determination and monitoring of neurodegeneration remain difficult. As the widely used MRI-based approaches, including the brain parenchymal fraction (BPF) have some limitations, complementary in vivo measures for neurodegeneration are necessary. Optical coherence tomography (OCT) is a potent tool for the detection of MS-related retinal neurodegeneration. However, crucial aspects including the association between OCT- and MRI-based atrophy measures or the impact of MS-related parameters on OCT parameters are still unclear. In this large prospective cross-sectional study on 104 relapsing remitting multiple sclerosis (RRMS) patients we evaluated the associations of retinal nerve fiber layer thickness (RNFLT) and total macular volume (TMV) with BPF and addressed the impact of disease-determining parameters on RNFLT, TMV or BPF. BPF, normalized for subject head size, was estimated with SIENAX. Relations were analyzed primarily by Generalized Estimating Equation (GEE) models considering within-patient inter-eye relations. We found that both RNFLT (p = 0.019, GEE) and TMV (p = 0.004, GEE) associate with BPF. RNFLT was furthermore linked to the disease duration (p<0.001, GEE) but neither to disease severity nor patients' age. Contrarily, BPF was rather associated with severity (p<0.001, GEE) than disease duration and was confounded by age (p<0.001, GEE). TMV was not associated with any of these parameters. Thus, we conclude that in RRMS patients with relatively short disease duration and rather mild disability RNFLT and TMV reflect brain atrophy and are thus promising parameters to evaluate neurodegeneration in MS. Furthermore, our data suggest that RNFLT and BPF reflect different aspects of MS. Whereas BPF best reflects disease severity, RNFLT might be the better parameter for monitoring axonal damage longitudinally. Longitudinal studies are necessary for validation of data and to further clarify the relevance of TMV

Climate Science Special Report: Fourth National Climate Assessment (NCA4), Volume I

New observations and new research have increased our understanding of past, current, and future climate change since the Third U.S. National Climate Assessment (NCA3) was published in May 2014. This Climate Science Special Report (CSSR) is designed to capture that new information and build on the existing body of science in order to summarize the current state of knowledge and provide the scientific foundation for the Fourth National Climate Assessment (NCA4)

Metabolic Changes in the Visual Cortex Are Linked to Retinal Nerve Fiber Layer Thinning in Multiple Sclerosis

OBJECTIVE: To investigate the damage to the retinal nerve fiber layer as part of the anterior visual pathway as well as an impairment of the neuronal and axonal integrity in the visual cortex as part of the posterior visual pathway with complementary neuroimaging techniques, and to correlate our results to patients' clinical symptoms concerning the visual pathway. DESIGN, SUBJECTS AND METHODS: Survey of 86 patients with relapsing-remitting multiple sclerosis that were subjected to retinal nerve fiber layer thickness (RNFLT) measurement by optical coherence tomography, to a routine MRI scan including the calculation of the brain parenchymal fraction (BPF), and to magnetic resonance spectroscopy at 3 tesla, quantifying N-acetyl aspartate (NAA) concentrations in the visual cortex and normal-appearing white matter. RESULTS: RNFLT correlated significantly with BPF and visual cortex NAA, but not with normal-appearing white matter NAA. This was connected with the patients' history of a previous optic neuritis. In a combined model, both BPF and visual cortex NAA were independently associated with RNFLT. CONCLUSIONS: Our data suggest the existence of functional pathway-specific damage patterns exceeding global neurodegeneration. They suggest a strong interrelationship between damage to the anterior and the posterior visual pathway

Approches protéomiques pour le développement de biomarqueurs chez l'amphipode d'eau douce Gammarus fossarum : découverte et caractérisation de protéines impliquées dans la fonction reproductrice

Among the tools for assessing biologic quality of aquatic ecosystems, biomarkers are ideally suited for the early detection of contaminant exposure and/or effects. Yet, because of the lack of fundamental knowledge of their molecular regulation, few specific developments have been carried out on invertebrates even though they account for more than 95% of animal biodiversity. Thanks to recent technological advances in nucleic and proteic information sequencing, discovery of new proteins is now possible for these organisms. Focussed on the use of an ecotoxicologically relevant species, the freshwater amphipod Gammarus fossarum and the problem of endocrine disruption, this doctoral thesis aims to discover new proteins involved in gammarid reproductive function and to propose specific biomarkers of endocrine disruption. With a first proteogenomic approach, an important protein catalogue was generated. Next, to identify proteins involved in gammarid reproduction, male and female reproductive tissue proteomes were compared, followed by the study of proteome dynamics in several physiological processes: oogenesis, embryogenesis and spermatogenesis. Finally, a last experiment on male gammarids challenged with different endocrine disrupter chemicals identified several candidate biomarkers of reprotoxicity. This study paves the way for quick developments of specific biomarkers for organisms of interest in ecotoxicologyParmi les outils existants pour l’évaluation de la qualité des milieux aquatiques, les biomarqueurs permettent de détecter précocement l’exposition et/ou les effets d’une contamination. Toutefois, en raison du manque de connaissance fondamentale de leur régulation au niveau moléculaire, peu de biomarqueurs ont été spécifiquement développés chez les invertébrés, alors que ces derniers représentent 95% de la biodiversité animale. Grâce aux récentes avancées technologiques dans le domaine du séquençage de l’information génétique et protéique, la découverte de nouvelles protéines chez ces organismes est à présent possible. Centré sur l’utilisation d’une espèce d’intérêt en écotoxicologique, l’amphipode d’eau douce Gammarus fossarum, et sur la problématique de la perturbation endocrine, ce travail doctoral a pour objectif de découvrir de nouvelles protéines impliquées dans la reproduction du gammare et de proposer des biomarqueurs spécifiques de reprotoxicité. Par une première approche protéogénomique, un important catalogue de protéines a été généré. Puis, afin d’identifier de nouvelles protéines impliquées dans la reproduction, une comparaison entre les protéomes des tissus reproducteurs mâle et femelle a été réalisée, suivi de l’étude de la dynamique du protéome au cours de différents processus physiologiques : ovogénèse, embryogénèse et spermatogénèse. Enfin, une dernière expérience sur des organismes mâles exposés à différents perturbateurs endocriniens a permis d’identifier différents candidats biomarqueurs de reprotoxicité. Cette étude ouvre la voie à des développements rapides de biomarqueurs spécifiques d’une espèce animale d’intérêt en écotoxicologie

Proteomic approaches for the development of biomarkers in the freshwater amphipod Gammarus fossarum : discovery and characterization of proteins involved in reproductive function

Parmi les outils existants pour l'évaluation de la qualité des milieux aquatiques, les biomarqueurs permettent de détecter précocement l'exposition et/ou les effets d'une contamination. Toutefois, en raison du manque de connaissance fondamentale de leur régulation au niveau moléculaire, peu de biomarqueurs ont été spécifiquement développés chez les invertébrés, alors que ces derniers représentent 95% de la biodiversité animale. Grâce aux récentes avancées technologiques dans le domaine du séquençage de l'information génétique et protéique, la découverte de nouvelles protéines chez ces organismes est à présent possible. Centré sur l'utilisation d'une espèce d'intérêt en écotoxicologique, l'amphipode d'eau douce Gammarus fossarum, et sur la problématique de la perturbation endocrine, ce travail doctoral a pour objectif de découvrir de nouvelles protéines impliquées dans la reproduction du gammare et de proposer des biomarqueurs spécifiques de reprotoxicité. Par une première approche protéogénomique, un important catalogue de protéines a été généré. Puis, afin d'identifier de nouvelles protéines impliquées dans la reproduction, une comparaison entre les protéomes des tissus reproducteurs mâle et femelle a été réalisée, suivi de l'étude de la dynamique du protéome au cours de différents processus physiologiques : ovogénèse, embryogénèse et spermatogénèse. Enfin, une dernière expérience sur des organismes mâles exposés à différents perturbateurs endocriniens a permis d'identifier différents candidats biomarqueurs de reprotoxicité. Cette étude ouvre la voie à des développements rapides de biomarqueurs spécifiques d'une espèce animale d'intérêt en écotoxicologieAmong the tools for assessing biologic quality of aquatic ecosystems, biomarkers are ideally suited for the early detection of contaminant exposure and/or effects. Yet, because of the lack of fundamental knowledge of their molecular regulation, few specific developments have been carried out on invertebrates even though they account for more than 95% of animal biodiversity. Thanks to recent technological advances in nucleic and proteic information sequencing, discovery of new proteins is now possible for these organisms. Focussed on the use of an ecotoxicologically relevant species, the freshwater amphipod Gammarus fossarum and the problem of endocrine disruption, this doctoral thesis aims to discover new proteins involved in gammarid reproductive function and to propose specific biomarkers of endocrine disruption. With a first proteogenomic approach, an important protein catalogue was generated. Next, to identify proteins involved in gammarid reproduction, male and female reproductive tissue proteomes were compared, followed by the study of proteome dynamics in several physiological processes: oogenesis, embryogenesis and spermatogenesis. Finally, a last experiment on male gammarids challenged with different endocrine disrupter chemicals identified several candidate biomarkers of reprotoxicity. This study paves the way for quick developments of specific biomarkers for organisms of interest in ecotoxicolog

Quasielastic and elastic scattering studies of aligned DMPC multilayers at different hydrations

Lipid model membranes such as 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DMPC) serve as role models for their more complex counterparts in biological systems. Quasielastic neutron scattering (QENS) [1-3], inelastic neutron scattering (INS) [4] and neutron spin echo spectroscopy (NSE) [5] have been employed to study local as well as collective dynamics of these membranes on a ps-ns time scale. Most of these studies lack a systematic investigation of the behavior of the model membranes in dependence on their hydration. We now started a detailed investigation of hydration effect on model membrane systems. The complexity of the dynamics can be further reduced by selective deuteration, which allows to distinguish between dynamics of different part of the lipid molecules. In the here presented work we have used chain deuterated DMPC-d54 to study the dynamics of the lipid head group. To probe both dynamics in the plane of the membrane and perpendicular to it, the samples were prepared on cleaned silicon wafers. The hydration for the two samples was adjusted by hydrating them for pure D2O and from a saturated salt solution respectively, resulting in two different states of hydration (repeat distance d=62.5 Å with 15 water molecules per lipid and d = 54.9 Å with 9 water molecules per lipid, respectively). The alignment and mosaicity were checked prior to the measurements for all samples by neutron diffraction and was found to be below 1°. QENS experiments were performed at the time-of-flight spectrometer TOFTOF at the research reactor FRMII in Munich (energy resolution: 56 μeV FWHM) in the temperature range from 5°C to 30°C to cover the main phase transition from the Pβ gel phase to the liquid crystalline Lα phase of DMPC which occurs around 23°C. Elastic incoherent neutron scattering (EINS) measurements were performed at the high momentum transfer backscattering spectrometer IN13 (energy resolution 8 μeV FWHM) and the cold neutron backscattering spectrometer IN16 (energy resolution 0.9 μeV FWHM) both at the Institut Laue-Langevin (ILL), Grenoble. For the QENS experiment elastic incoherent structure factors (EISF) and diffusion constants were extracted, which indicate that hydration has a clear influence on the mobility of this system [6]. The integrated intensities from the EINS experiments showed a shift of the main phase transition as a function of hydration which coincides with a change of the slopes of the mean square displacements [7]. In addition to earlier QENS [1-3] and backscattering [8] investigations, these experiments extend our knowledge of model membrane systems. References [1] S. König et al., J.Phys.II France, 2 (1992) 1589-1615 [2] M.C. Rheinstädter et al., Phys. Rev. E 75 (2007) 011907 [3] S. Busch et al., JACS 132, (2010), 3232-3233 [4] M.C. Rheinstädter et al., Phys Rev. Lett. 93 (2004) 108107 [5] M.C. Rheinstädter et al., Phys. Rev. Lett. 97 (2006) 048103 [6] M. Trapp et al., in preperation [7] M. Trapp et al., Spectrosc.-int. J., accepted (2010) [8] M.C. Rheinstädter et al., Phys. Rev. E 71 (2005) 061908 (2002

Probing Model Membrane Local Dynamics

Local dynamics of phospholipids are effected by various parameters as temperature, pressure, hydration oradditives. In recent years neutron scattering has probed this dynamics at various time and length scales in the nanotopicosecond time range. We will show the influence of small molecules as short chain alcohols and cholesterol onthe phospholipid local dynamics as probed by elastic and inelastic neutron scattering. By these methods local diffusioncoefficients and motions are derived as well as thermodynamic parameters