Luc Bauchet

Minimum information about animal experiments: supplier is also important

It has now been established that functional recovery after spinal cord injury (SCI) depends on several parameters, including animal strain. Here we demonstrate that rats from the same strain (Wistar) but from two independent commercial suppliers present different motor, sensory, and autonomic outcomes after a standard model of SCI, the so‐called compression model. Recovery is correlated with the extension of the lesion, and we show that the vertebral canal diameter varies between the two suppliers. To substantiate this point, we carried out another set of experiments, with the so‐called contusion model, which requires bone ablation and thus whose extension is not related to vertebral canal diameter. We show that there is no difference between the two suppliers. The purpose of our communication is to alert researchers on how crucial it is to control experimental parameters as closely as possible and to establish a standard for animal experiment in order to avoid unexpected biases.

Épidémiologie des glioblastomes

An increasing incidence of glioblastoma has been observed over the last 30 years. Improvements in diagnostic tools such as CT scans and MRI, changes observed in histological classifications, and adjustments in neurosurgical practices have contributed substantially to this increase. Moreover, the aging of the population and the increasing occurrence of glioblastoma beyond 60 years of age are additional explanations. In Gironde (France), where a specialized registry has been established, the annual incidence of glioblastoma is 4.96/100,000. Wide geographic variations are observed, possibly linked to ethnicity. However, the role of intrinsic and/or extrinsic factors cannot be ruled out. Comparing data between registries is difficult and requires taking into account periods of recruitment and diagnostic tools. Ethnicity, age, sex, hereditary syndromes, some constitutive polymorphisms, and brain irradiation are the established risk factors Allergies or asthma, certain viral infections, autoimmune diseases, nonsteroidal anti-inflammatory drug intake, substitutive hormonal therapy, and dietary antioxidant intake are the established protective factors. Many studies on electromagnetic fields - in particular cellular phones - pesticides, solvents, and other factors have been published. Until now, the results are discordant or are not confirmed because of methodological limitations. Future studies combining constitutive polymorphisms and exposure assessment are likely to provide consistent and important data that will improve our knowledge in the epidemiology of glioblastoma.

Isolation and Culture of Precursor Cells from the Adult Human Spinal Cord

Our group recently provided evidence for the presence of neural stem cells and/or progenitor cells in the adult human spinal cord. In this chapter, we review materials and methods to harvest high-quality samples of thoracolumbar, lumbar, and sacral adult human spinal cord from brain-dead patients who had agreed to donate their bodies to science for therapeutic and scientific advances. The methods to culture precursor cells from the adult human spinal cord are also described.

Stable Isotope Labeling by Amino acid in Vivo (SILAV): a new method to explore protein metabolism

RATIONALE Intravenous administration of stable isotope labeled amino acid ((13)C6-leucine) to humans recently made it possible to study the metabolism of specific biomarkers in cerebrospinal fluid (CSF) using targeted mass spectrometry (MS). This labeling approach could be of great interest for monitoring many leucine-containing peptides in parallel, using high-resolution MS. This will make it possible to quantify the rates of synthesis and clearance of a large range of proteins in humans with a view to obtaining new insights into protein metabolism processes and the pathophysiology of diseases such as Alzheimers disease. METHODS Proteins from human lumbar and ventricular CSF samples collected at different times after intravenous (13)C6-leucine infusion were digested enzymatically with LysC/trypsin after being denatured, reduced and alkylated. Desalted tryptic peptides were fractionated using Strong Cation eXchange chromatography (SCX) and analyzed using nanoflow liquid chromatography (nano-LC) coupled to a QTOF Impact II (Bruker Daltonics) mass spectrometer. Data-dependent acquisition (DDA) mode was used to identify and quantify light and heavy (13)C6-leucine peptides. The ratios of (13)C6-leucine incorporation were calculated using the Skyline software program in order to determine the rates of appearance and clearance of proteins in the CSF. RESULTS After SCX fractionation and quadrupole time-of-flight (QTOF) analysis, 4528 peptides containing leucine were identified in five fractions prepared from 40 μL of CSF. Upon analyzing one of these fractions, 66 peptides (2.7%) corresponding to 61 individual proteins had significant and reproducible rate of (13)C6-leucine incorporation at various time points. The plots of the light-to-heavy peptide ratios showed the existence of proteins with different patterns of appearance and clearance in the CSF. CONCLUSIONS The Stable Isotope Labeling Amino acid in Vivo (SILAV) method presented here, which yields unprecedented information about protein metabolism in humans, constitutes a promising new approach which certainly holds great potential in the field of clinical proteomics.

Neurochirurgie et neuro-oncologie : état des lieux (II): Recensement des protocoles de recherche sur les tumeurs cérébrales

Resume Objectif de l’etude L’objectif de ce deuxieme volet de l’enquete du Club de Neuro-Oncologie de la Societe Francaise de Neurochirurgie etait d’evaluer l’implication des neurochirurgiens francais dans les protocoles de recherche clinique et fondamentale. Methode Un questionnaire intitule « Recensement des protocoles de recherche (fondamentale et clinique) sur les tumeurs cerebrales en cours ou en projet dans votre service » a ete adresse en decembre 2003 a tous les services de neurochirurgie francais publics et prives. Pour chaque protocole de recherche devaient etre precises : titre du protocole, caractere mono ou multicentrique, nom de l’investigateur principal de l’etude, nom du(des) neurochirurgien(s) coordonnateur(s) implique(s) dans le service, theme du protocole (epidemiologie, imagerie, biologie/genetique, therapeutique), type de tumeur concerne, financement, partenariat eventuel. Resultats Vingt-trois centres ont repondu. Soixante trois protocoles differents ont ete cites. Il y avait 6 etudes epidemiologiques et 7 etudes d’imagerie, 27 etudes biologiques ou de genomique et 15 protocoles therapeutiques concernant les tumeurs gliales, et 8 etudes biologiques concernant les tumeurs cerebrales non gliales. Chaque protocole est ici presente avec le titre et les renseignements rapportes sur la fiche. Conclusion En depit de son caractere non exhaustif, cette enquete confirme la forte implication des neurochirurgiens dans la recherche sur les tumeurs cerebrales en France.

Reversible hypothalamic-pituitary axis involvement in a patient with intravascular lymphomatosis.

Journal of Neuroradiology - In Press.Proof corrected by the author Available online since mardi 1 juillet 2014

Research in Acute Traumatic Spinal Cord Injuries: Progresses and Prospects

1Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier, France 2INSERM U1051, Pathologies sensorielles, neuroplasticité et thérapies, Institute for Neurosciences of Montpellier, Saint Eloi Hospital, Montpellier Cedex 05, France 3Integrative Biology of Neurodegeneration, IKERBASQUE Basque Foundation for Science, Neuroscience Department, University of the Basque Country UPV/EHU, Bilbao, Spain 4CNRS, L2C UMR5221, Montpellier, France