L'Abri n°1 de l'Aulp du Seuil (Isère, Chartreuse, St-Bernard-du-Touvet): synthèse des résultats préliminaires et discussion sur les modalités d'exploitation territoriale au Mésolithique et au Néolithique ancien

Situé à 1700 m d'altitude, au fond d'un vallon creusé dans un synclinal perché urgonien, isolé et difficile d'accès, ce site a livré six abris sous bloc et une station de plein air. Nous présentons ici les résultats préliminaires des fouilles en cours de l'abri no 1. La stratigraphie a permis de reconnaitre quatre couches bien individualisées et calées chronologiquement. La couche A correspond à la période médiévale, la couche B au 1er Âge du Fer et au Néolithique final, la couche C1 au Néolithique ancien et au Mésolithique récent, alors que les couches C2, C3 et D1 se rapportent au Mésolithique moyen. Les espèces chassées les mieux représentées sont le bouquetin, le chamois et le cerf. Les données de la paléobotanique indiquent un environnement caractéristique de l'étage montagnard, un paysage boisé mais ouvert avec, au Mésolithique, une représentation des feuillus aujourd'hui absents du site indiquant des conditions climatiques plus tempérées. Les résultats préliminaires des études sur les matières premières, qui mettent en évidence des zones d'approvisionnement plus ou moins éloignées, témoignent de la mobilité des groupes mésolithiques, de leur connaissance et de leur exploitation du milieu montagnard

A transgenic mouse expressing CHMP2B intron5 mutant in neurons develops histological and behavioural features of amyotrophic lateral sclerosis and frontotemporal dementia

International audienceMutations in the charged multivesicular body protein 2B (CHMP2B) are associated with frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), and with a mixed ALS-FTD syndrome. To model this syndrome, we generated a transgenic mouse line expressing the human CHMP2Bintron5 mutant in a neuron-specific manner. These mice developed a dose-dependent disease phenotype. A longitudinal study revealed progressive gait abnormalities, reduced muscle strength and decreased motor coordination. CHMP2Bintron5 mice died due to generalized paralysis. When paralyzed, signs of denervation were present as attested by altered electromyographic profiles, by decreased number of fully innervated neuromuscular junctions, by reduction in size of motor endplates and by a decrease of sciatic nerve axons area. However, spinal motor neurons cell bodies were preserved until death. In addition to the motor dysfunctions, CHMP2Bintron5 mice progressively developed FTD-relevant behavioural modifications such as disinhibition, stereotypies, decrease in social interactions, compulsivity and change in dietary preferences. Furthermore, neurons in the affected spinal cord and brain regions showed accumulation of p62-positive cytoplasmic inclusions associated or not with ubiquitin and CHMP2Bintron5 As observed in FTD3 patients, these inclusions were negative for TDP-43 and FUS. Moreover, astrogliosis and microgliosis developed with age. Altogether, these data indicate that the neuronal expression of human CHMP2Bintron5 in areas involved in motor and cognitive functions induces progressive motor alterations associated with dementia symptoms and with histopathological hallmarks reminiscent of both ALS and FTD

Systemic down-regulation of delta-9 desaturase promotes muscle oxidative metabolism and accelerates muscle function recovery following nerve injury.

The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS). Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles

Gene expression specific to the motor end plate in SCD1 knockout mice.

<p>Expression of AChR-α, AChR-γ, AChR-ε and MuSK in gastrocnemius and tibialis anterior from SCD1 knockout mice (brown columns) and wild-type littermates (white columns). *<i>P</i><0.05, ***<i>P</i><0.001 (Unpaired t-test, n = 4–11).</p

Muscle function recovery in SCD-deficient mice submitted to nerve crush.

<p>Restoration of muscle grip strength in SCD1 knockout mice (A) or MF-438 treated mice (C) (black circles) and corresponding control littermates (white circles) at the indicated post-operation times. ***<i>P</i><0.001 (2-way ANOVA, n = 4–12). Percentage of electromyography episodes of spontaneous activity in SCD1 knockout mice (Inset A) or MF-438 treated mice (Inset C) (KO or MF, brown columns) and corresponding control littermates (WT or CT, white columns) two weeks after sciatic nerve crush. *<i>P</i><0.05 (Unpaired t-test, n = 4–7). (B) Relative density of muscle fiber types in ipsilateral and contralateral tibialis anterior from SCD1 knockout mice and wild-type littermates two weeks after sciatic nerve crush. According to SDH histochemistry, fibers were classified as dark brown colored fibers with high metabolic oxidative capacity (brown columns), pale brown colored fibers with medium oxidative capacity (orange columns) and non-satined fibers (white columns). *<i>P</i><0.05 and ***<i>P</i><0.001 (1-way ANOVA followed by Tukey's multiple comparison test, (n = 4–6). (D) Kaplan-Meier curves showing the percentage of MF-438 treated mice (black circles) and control littermates (white circles) that started to exhibit a grip strength distinct from zero after initial total paralysis. Logrank test (n = 10–11). Inset D, averaged time at start of recovery in MF-438 treated mice (MF, brown column) and control littermates (CT, white column). *<i>P</i><0.05 (Unpaired t-test, n = 10–11).</p

Effects of MF-438 on metabolism and muscle function.

<p>(A) C16:1/C16:0 and C18:1/C18:0 fatty acid ratio in plasma from MF-438 treated mice (brown columns) and control littermates (CT, white columns). ***<i>P</i><0.001 (Unpaired t-test, n = 4–6). (B) Time course of respiratory quotient (RQ) before and after treatment with MF-438 at a dose of 10 mg/kg body mass/day (indicated by the black bar) (n = 4). Time course of body mass (C), muscle grip strength expressed as a percentage of day 0 (D), and specific grip strength, as determined by normalizing peak force to body mass (E), in mice fed regular chow (white circles) and mice fed regular chow supplemented with MF-438 (black circles). **<i>P</i><0.01 (2-way ANOVA followed by Bonferroni test, n = 5–6). (F) Expression of PGC1-α, AChR-α, and MuSK in gastrocnemius from MF-438 treated mice (brown columns) and control littermates (white columns). *<i>P</i><0.05 (Unpaired t-test, n = 3–9).</p

SCD1 expression in ALS patient muscle and after nerve injury.

<p>(A) Expression of SCD1 and SCD5 in deltoid muscle biopsies from ALS patients and healthy subjects (CT, white columns), as identified by microarray analysis of the database deposited at <a href="http://www.ebi.ac.uk/arrayexpress/(accession" target="_blank">http://www.ebi.ac.uk/arrayexpress/(accession</a> number E-MEXP-3260) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064525#pone.0064525-Pradat1" target="_blank">[12]</a>. ALS samples were obtained from muscle not clinically or electromyography affected (Unaff, orange columns) and from muscle with advanced pathology, characterized by reduced strength and neurogenic electromyography pattern (Aff, brown columns). *<i>P</i><0.05 (1-way ANOVA followed by Tukey's multiple comparison test, n = 4–10). (B) Expression of SCD1 in gastrocnemius following sciatic nerve axotomy (Axo) or crush at indicated post-operation days. Contralateral muscle expression is represented by 100% baseline. **<i>P</i><0.01, ***<i>P</i><0.001 (One sample t-test, n = 4–10).</p

Metabolic phenotype of muscle from SCD1 knockout mice.

<p>(A) Expression of PGC1-α, PPARα and PDK4 in gastrocnemius and tibialis anterior from SCD1 knockout mice (brown columns) and wild-type littermates (white columns). *<i>P</i><0.05, **<i>P</i><0.01 (Unpaired t-test, n = 3–11). (B) Number of muscle fibers in tibialis anterior from SCD1 knockout mice (KO, brown column) and wild-type littermates (WT, white column). *<i>P</i><0.05 (Unpaired t-test, n = 7–10). (C) Distribution of the calibers of muscle fibers in tibialis anterior from SCD1 knockout mice (327 fibers, black circles) and wild-type littermates (283 fibers, white circles). Representative microphotographs of wild-type and knockout tibialis anterior are shown. (D) Averaged cross-sectional area of SDH-positive and SDH-negative fibers in tibialis anterior from SCD1 knockout mice (brown columns) and wild-type littermates (white columns). *<i>P</i><0.05, **<i>P</i><0.01 (Unpaired t-test, n = 7–10). (E) Number of SDH-positive (orange bars) and SDH-negative fibers (white bars) in tibialis anterior from SCD1 knockout mice (KO) and wild-type littermates (WT). ***<i>P</i><0.001 (Chi-square test, n = 283–327).</p

Castellar – Pendimoun (Alpes-Maritimes). Avancement des travaux de recherche en 2014 (contribution 9)

Castellar – Pendimoun (Alpes-Maritimes). Avancement des travaux de recherche en 2014 (contribution 9

Impact of Expert Pathologic Review of Lymphoma Diagnosis: Study of Patients From the French Lymphopath Network

International audiencePurposeTo prospectively assess the clinical impact of expert review of lymphoma diagnosis in France.Materials and MethodsFrom January 2010 to December 2013, 42,145 samples from patients with newly diagnosed or suspected lymphomas were reviewed, according to the 2008 WHO classification, in real time by experts through the Lymphopath Network. Changes in diagnosis between referral and expert review were classified as major or minor according to their potential impact on patient care.ResultsThe 42,145 reviewed samples comprised 36,920 newly diagnosed mature lymphomas, 321 precursor lymphoid neoplasms, 314 myeloid disorders, and 200 nonhematopoietic neoplasms, with 4,390 benign lesions. There were 4,352 cutaneous and 32,568 noncutaneous lymphomas. The most common mature noncutaneous lymphomas were diffuse large B-cell lymphomas (32.4%), follicular lymphomas (15.3%), classic Hodgkin lymphomas (13%), peripheral T-cell lymphomas (6.3%) of which angioimmunoblastic T-cell lymphomas (2.3%) were the most frequent, and mucosa-associated lymphoid tissue lymphomas (5.8%). A diagnostic change between referral and expert review occurred in 19.7% of patients, with an estimated impact on patient care for 17.4% of patients. This rate was significantly higher for patients sent with a provisional diagnosis seeking expert second opinion (37.8%) than for patients sent with a formal diagnosis (3.7%). The most frequent discrepancies were misclassifications in lymphoma subtype (41.3%), with 12.3% being misclassifications among small B-cell lymphoma entities. Fewer than 2% of changes were between benign and malignant lymphoid conditions. Minor changes (2.3%) mostly consisted of follicular lymphoma misgrading and diffuse large B-cell lymphoma subtype misclassification.ConclusionTo our knowledge, this study provides the largest ever description of the distribution of lymphoma entities in a western country and highlights how expert review significantly contributes to a precise lymphoma diagnosis and optimal clinical management in a proportion of patients