Mary Anning’s legacy to French vertebrate palaeontology

peer reviewedThe real nature of marine reptile fossils found in England in between the 1700s to the beginning of the 1900s remained enigmatic, until Mary Anning's incredible fossil discoveries and their subsequent study by eminent English and French scientists. In 1820, Georges Cuvier acquired several ichthyosaur specimens found by Mary Anning, now kept or displayed in the Palaeontology Gallery of the MNHN in Paris. Four years later, Cuvier obtained a plesiosaur specimen from Mary Anning, only the second ever discovered. Cuvier was fascinated by these fossils and their study allowed him to apply his comparative anatomical method and to support his catastrophist theory. We re-examined these important specimens from an historical point of view and herein describe them taxonomically for the first time since Cuvier’s works. The Paris specimens belong to two different ichthyosaur genera (Ichthyosaurus and Leptonectes) and one plesiosaur genus (Plesiosaurus)

Differential between Protein and mRNA Expression of CCR7 and SSTR5 Receptors in Crohn's Disease Patients

Crohn's disease (CD) is a multifactorial chronic inflammatory bowel disease of unknown cause. The aim of the present study was to explore if mRNA over-expression of SSTR5 and CCR7 found in CD patients could be correlated to respective protein expression. When compared to healthy donors, SSTR5 was over-expressed 417 ± 71 times in CD peripheral blood mononuclear cells (PBMCs). Flow cytometry experiments showed no correlation between mRNA and protein expression for SSTR5 in PBMCs. In an attempt to find a reason of such a high mRNA expression, SSTR5 present on CD PBMCs were tested and found as biologically active as on healthy cells. In biopsies of CD intestinal tissue, SSTR5 was not over-expressed but CCR7, unchanged in PBMCs, was over-expressed by 10 ± 3 times in the lamina propria. Confocal microscopy showed a good correlation of CCR7 mRNA and protein expression in CD intestinal biopsies. Our data emphasize flow and image cytometry as impossible to circumvent in complement to molecular biology so to avoid false interpretation on receptor expressions. Once confirmed by further large-scale studies, our preliminary results suggest a role for SSTR5 and CCR7 in CD pathogenesis

Effects of Hormone Agonists on Sf9 Cells, Proliferation and Cell Cycle Arrest

Methoxyfenozide and methoprene are two insecticides that mimic the action of the main hormones involved in the control of insect growth and development, 20-hydroxyecdysone and juvenile hormone. We investigated their effect on the Spodoptera frugiperda Sf9 cell line. Methoxyfenozide was more toxic than methoprene in cell viability tests and more potent in the inhibition of cellular proliferation. Cell growth arrest occurred in the G2/M phase after a methoprene treatment and more modestly in G1 after methoxyfenozide treatment. Microarray experiments and real-time quantitative PCR to follow the expression of nuclear receptors ultraspiracle and ecdysone receptor were performed to understand the molecular action of these hormone agonists. Twenty-six genes were differentially expressed after methoxyfenozide treatment and 55 genes after methoprene treatment with no gene in common between the two treatments. Our results suggest two different signalling pathways in Sf9 cells

GPCR expression in Crohn's disease : identification of biomarkers and therapeutic targets.

L’importance des maladies inflammatoires chroniques de l'intestin (MICI) en termes d’incidence, de morbidité, et d’impact socio-économique est incontestable. Un des enjeux du projet est de classer les différentes types de MICI sur une base moléculaire assez fiable pour pouvoir développer une thérapie adaptée à chaque classe, donc une thérapie plus efficace, mieux ciblée et avec moins d’effets secondaires. Pour ce faire, nous avons développé une stratégie originale en utilisant un transcriptome dédié à la famille des RCPG et une technologie beaucoup plus sensible et reproductible que celle des puces à ADN. L’étude des PBMC chez les malades de Crohn nous a permis d’identifier un groupe de gènes dont l’expression est dérégulée de manière significative. Ces résultats ouvrent des perspectives intéressantes tant au niveau du diagnostic de la maladie de Crohn qu’au niveau thérapeutique. De plus, nous avons mis en évidence des récepteurs qui, à notre connaissance, n’ont jamais été impliqués dans la réponse immunitaire lors de l’activation des PBMC par le LPS. Parmi les plus intéressants figurent des gènes classés orphelins : GPR 155 et GPR77. Les récepteurs GPR4, CCR5 et P2RY2 qui sont dérégulés chez les malades de Crohn lors de l’activation des PBMC sont particulièrement importants pour comprendre le développement de la maladie. Nos résultats préliminaires avec les biopsies sont aussi prometteurs mais la stratégie s’avère plus difficile à mettre en oeuvre. Nous avons analysé l’expression protéique de 2 récepteurs SSTR5 et CCR7 dérégulés au niveau de la transcription respectivement dans les PBMC et les biopsies au moyen de la cytométrie en flux et de la microscopie confocale. Nos résultats montrent que ces 2 technologies sont des technologies de choix et complémentaires de celles du transcriptome pour la validation des cibles thérapeutiques.The importance of inflammatory bowel disease (IBD) in incidence, morbidity, and socio-economic impact is undeniable. One goal of this project is to classify the different IBD on a molecular basis that would be reliable enough in order to develop a more effective, more accurate and with less side effects therapy. To reach this goal we used an original strategy taking advantages of both a GPCR family dedicated transcriptome and a more sensitive technology than that with the oligonucleotide arrays. The study on PBMC from patients with Crohn's disease has revealed a group of genes which expression is significantly changed in comparison with control individuals. These findings might provide some interesting new perspectives for the diagnostic of the Crohn's disease as for its therapy. Futhermore we have uncovered some receptors that, to our knowledge, have never been shown to be involved in the immune response upon activation of PBMC by LPS. Amongst the most significantly deregulated genes there are two orphan genes : GPR 155 et GPR77. Moreover receptors GPR4, CCR5 and P2RY2 that appeared differently expressed upon LPS activation in PBMC in patients with Crohn's disease versus control individual might give some attractive insights in the pathogenesis of the disease. Our preliminary results with biopsies are also promising but the strategy requires more effort to control the variability of the tissues. In order to invalidate our results at the protein level we investigate the expression of two receptors SSTR5 and CCR7 using flow cytometry and confocal microscopy. Our results indicate that both technologies are well suitable and complementary in order to invalidate the biomarkers and potential therapeutic targets

Etude des crocodyliformes fini Crétacé-Paléogène du bassin des Oulad Abdoun (Maroc) et comparaison avec les faunes africaines contemporaines (systématique, phylogénie et paléobiogéographie)

Grâce à un intense travail de terrain entrepris au printemps 2000 dans le cadre d'une collaboration entre différents organismes français et marocains, de nombreux restes de Crocodyliformes ont été mis au jour dans les dépôts marins phosphatés du Crétacé et Paléogène du Bassin des Oulad Abdoun du Maroc. Deux taxons ont été trouvés dans ces dépôts, les eusuchiens et les dyrosaures, représentés respectivement par quatre et huit espèces. Parmi les eusuchiens on peut noter la présence de trois gavialoïdes dont un thoracosaure, dont c'est d'ailleurs la première description en Afrique. Une analyse phylogénétique révèle que Thoracosaurus est un taxon monophylétique, et que Maroccosuchus zennaroi, un eusuchien des phosphates marocains déjà décrit mais enrichi de nouveau matériel, est le plus primitif des tomistominés. Les Dyrosauridae constituent un groupe dont les représentants étaient jusque là très mal connus. Ainsi, une révision taxonomique montre que " Hyposaurus " bequaerti doit être réattribué au genre Congosaurus, que Hyposaurus wilsoni, H. nopcsai et Rhabdognathus rarus sont des nomina dubia, et que deux crânes de Rhabdognathus sont attribués à deux nouvelles espèces. Trois nouveaux dyrosauridés des phosphates marocains sont décrits, et l'analyse phylogénétique des Dyrosauridae dans le contexte des Crocodyliformes montre la persistance des problèmes liés à la convergence des formes longirostres dans les analyses phylogénétiques. La diversité observée dans le Bassin des Oulad Abdoun montre une forte diversification au Paléocène, alors que les crocodyliformes y sont extrêmement rares au Maastrichtien. Ainsi, n'ont-ils apparemment pas subi l'influence de la crise K-T, mais plutôt profité de la disparition des autres reptiles marins pour coloniser la majeure partie de leurs niches écologiques dès le PaléocèneThanks to an intensive field work undertaken in spring 2000 with the collaboration between various French and Moroccan organisations, numerous Crocodyliformes remains has been recovered from the phosphatic marine layers from the Cretaceous and Paleogene of the Oulad Abdoun Basin, Morocco. Two taxa have been found in these deposits, eusuchians and dyrosaurids, represented by four and eight species respectively. Among eusuchians, the occurence of three gavialoids can be noted. One is a thoracosaur, which are reported for the first time in Africa. A phylogenetic analysis reveals that Thoracosaurus is a monophyletic taxa, and Maroccosuchus zennaroi, a previously described eusuchian from the phosphates of Morocco but completed with new material, is the most primitive tomistomine. Until know, the dyrosaurids formed a poorly known taxa. A taxonomic revision shows that "Hyposaurus" bequaerti should be transferred to Congosaurus, that Hyposaurus wilsoni, H. nopcsai and Rhabdognathus rarus are nomina dubia, and that two skulls from Rhabdognathus are two new species. Three new dyrosaurids from Morocco are described, and a phylogenetic analysis of Dyrosauridae within the Crocodyliformes setting shows that convergences due to the longirostrine morphology remain problematic in phylogenetic analyses. The diversity observed in the Oulad Abdoun Basin indicates a strong diversification during the Paleocene, whereas the Crocodyliformes were extremely rare during the Maastrichtian. Then, they have apparently not been affected by the K-T crisis, but probably have taken advantage of the other marine reptile disappearance, to colonise the main part of their ecological niches as soon as the PaleocenePARIS-Museum Hist.Naturelle (751052304) / SudocSudocFranceF

La thérapie cognitivo-comportementale peut-elle être adaptée dans l'usage problématique des réseaux sociaux ?

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Serials: Passion or Addiction? Evaluation Based on Quantitative and Case Study.

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