Les travaux micropaléontologiques d’Alcide d’Orbigny

D’Orbigny has created the order of Foraminifera for minute animals classed, at this time, amongst Cephalopoda, and proposed the first classification of this order in 1826, laying the foundations of micropalaeontology. All along his life, he described, figured or clarified diagnosis of about 1500 recent and fossil species. His collections, stored in the National Museum of Natural History in Paris, represent an inestimable patrimony and are still actively consulted. Several micropalaeontologists had contributed to their valorisation and recognised the validity of most of his species. Nowadays, one hundred and two are considered as type species of genera.     

Cretaceous Bivalves and Alcide d’Orbigny

The main publications on Cretaceous Bivalves of Alcide d’Orbigny are the Paléontologie française – Terrains crétacés. III. Lamellibranches (1843–1847) and the Prodrome de stratigraphie universelle, vol. II (1850). The importance and influence of these publications for today’s taxonomic palaeontology are discussed. It is shown that the Paléontologie française continues to be one of the major 19th-century papers but that the Prodrome is only rarely referred to.     

Conception et suites de la Paléontologie française d’Alcide d’Orbigny

The whole formed by his Paléontologie française, his Prodrome, and his Cours élémentaire, which are closely linked, constitutes one of the major parts of Alcide d’Orbigny’s scientific production, in which he exposed his concept of Palaeontology as a science closely related with Zoology and as an indispensable tool for Stratigraphy. The result was a remarkable impulsion for palaeontological and stratigraphical research, which from that time developed on new scientific foundations. Two annexes complete this communication, the first concerning the ‘Comité de la Paléontologie française’ (1860–1893), the second specifying the publication dates of four volumes of the Paléontologie française.     

Alcide d’Orbigny entre Cuvier et Lamarck

In the History of Science, Alcide d’Orbigny has the distinctive characteristic to be placed, between Cuvier and Lamarck, who were the two masters of Natural Science for most of the 19th century. It is in this historical context that Alcide d’Orbigny lived. Of Cuvier, he remembered ideas on disasters and species fixedness without using the same evidence, for he was not a vertebrist. Of Lamarck, he rejected the ideas on life continuity and species transformation while using the research field opened by the Zoology and Invertebrate Palaeontology founder. Alcide d’Orbigny’s originality was to use Lamarck’s Invertebrate fossils as evidence of the ideas that Cuvier had based on Vertebrate fossils.     

Les voyages biostratigraphiques d’Alcide d’Orbigny en France et dans les régions limitrophes

The numerous travels made by Alcide d’Orbigny during about twenty years, between 1834 and 1855, essentially for biostratigraphical investigations, were almost never recalled in the scientific papers. The data contained in his various publications concerning the palaeontological sites where he collected himself fossil samples allowed to list nearly 400 localities where he worked in France and adjacent regions, mainly on Jurassic and Cretaceous deposits.     

Le « créationnisme » d’Alcide d’Orbigny et les fondements de la théorie biostratigraphique

D’Orbigny was more interested in the discontinuities of life history than in the origin of species. He looked for reference points to correlate geological strata and to reconstruct their history. This allowed him to formalise the concept of stratigraphic stage and to propose the first geological time scale. Therefore, one of the results was that he was unjustly considered as one of the leaders of the creationism school, because he used the ambiguous term ‘creation’ to designate the renewal of fauna after catastrophic events, but without providing a definition and with a meaning that was probably different from those of his successors.     

Alcide d’Orbigny,un précurseur dans l’étude de la faune du Danien du bassin de Paris

One of the major contributions of Alcide d’Orbigny to palaeontology is his work on the Danian of the Paris Basin. The Danian material includes well-preserved external imprints of Invertebrates. By making casting of these imprints, Alcide d’Orbigny inaugurated an original technique, which enabled him to describe more than 40 species. The question of the age of the Danian localities has long been debated since that time. It was settled once and for all in the seventies by micropalaeontologists.     

Le développement de l’inventaire de dépistage ERIraos: un outil global d’appréciation du risque d’évolution psychotique

Adequate identification of patients for early intervention programmes requires reliable and valid assessment tools. Within the German Schizophrenia Network (Kompetenznetz Schizophrenie) a set of schedules for early detection of schizophrenia has been proposed: the Early Recognition Inventory ERIraos. ERIraos is a two-step procedure with a 17-item checklist used at step 1 by GPs, psychologists, teachers, while a comprehensive 110-item symptom list is applied at early intervention centres at the expert level. In addition, ERIraos allows the assessment of several risk factors for psychosis such as familial load, childhood deficiencies, alcohol and drug use by special modules. Some preliminary results are presented here. The frequency of the 17 checklist symptoms increases from the early to the late prodrome, and more specific symptoms occur over time. The 17 checklist symptoms are grouped by factor analysis to 5 factors (psychotic, depressive, disorganised, withdrawn, dysphoric). In addition to prodromal symptoms, most patients (86.2%) report at least one additional risk factor (mean: 1.7 risks). 68% demonstrate some schizotypal features, 53% report alcohol and/or drug consumption, 24% demonstrate some deficiency or delay in childhood development, 21% report definite obstetric or birth complications, and 10% have a family history of schizophrenia or some schizophrenia-like diagnosis in first degree relatives. So far, the results are of a preliminary nature, and when sufficient information on psychotic transitions is available, the predictive value of ERIraos will be determined.     

Alcide dˈOrbigny et les Rudistes

In the Paléontologie française (1850), Alcide dˈOrbigny described 78 species of Rudists found in geological beds in France.     

Alcide d’Orbigny et la Bolivie (1825–1857)

The evaluation of d’Orbigny’s contribution to Bolivian studies implies putting it in relation with the economic and political context prevailing before, during, and after his travel in this country, between 1830 and 1833. This paper deals with the following topics: the crisis of the silver mines in Potosi, the achievements of the governments of Santa Cruz (1829–1839) and Ballivián (1841–1847), and the various projects intending to open Bolivian lowlands to navigation and colonisation. Finally, some important documents show that d’Orbigny remains concerned with Bolivia many years after he returned to France.     

Les Crustacés récoltés par dˈOrbigny en Amérique du Sud et déposés au Muséum national dˈhistoire naturelle,Paris

The important collection of Crustacea assembled by dˈOrbigny during his voyage of exploration in South America (1826–1834) was studied by Henri Milne Edwards and Hippolyte Lucas (1842–1844) in their contribution to the natural history of the Voyage en Amérique méridionale. In the present paper, this material, mainly crabs, deposited in the dry collection of the ‘Muséum national dˈhistoire naturelle’, Paris, is reviewed. The authors of the described taxa and their dates of publication are specified, lectotypes are designated, and a list of the currently valid taxa is provided.     

Stratégie d’étude des anticorps anti-nucléaires

Le terme d’anticorps anti-nucléaires (ANA), consacré par l’usage, est trop restrictif puisque certains de ces anticorps reconnaissent des antigènes cytoplasmiques. Un très grand nombre d’ANA a été identifié au cours des 30 dernières années. Seul un nombre restreint de ceux-ci est spécifiquement associé à des maladies précises, connues sous le vocable de connectivites. Toutefois, des ANA peuvent assui être rencontrés dans d’autres affections, un syndrome infectieux ou inflammatoire, une néoplasie, une maladie spécifique d’organe, en particulier les maladies du foie comme l’hépatite auto-immune et certaines cholangiopathies. Enfin, il ne faut pas oublier l’apparition d’ANA survenant lors de la prise de certains médicaments. La spécificité de ces anticorps est tout à fait différente de celle que l’on observe dans les connectivites.     

Liste inédite des Reptiles et Amphibiens récoltés par Alcide dˈOrbigny en Amérique méridionale

The complete list of Reptiles and Amphibians collected by dˈOrbigny in South America (Uruguay, Argentina, Chile, Bolivia) is published for the first time. The list consists of six species of Chelonians, 26 of Saurians, 22 of Ophidians and 16 of Amphibians (one Gymnophiona and 15 Anura). In this list, 31 species were new and are still valid. The plates were published separately and prior to the publication of the ‘Reptiles’ chapter in the Voyage dans lˈAmérique méridionale, and sometimes before the corresponding volume of the Erpétologie générale of Duméril and Bibron 〚3〛. The publication dates of the plates change the known name, author(s) and dates of the several figured species.     

Impact d’une réduction d’activité sur la mesure de la fraction d’éjection du ventricule gauche sur caméra D-SPECT

IntroductionRadionuclide ventriculography provides a reproducible measurement of the left ventricular fraction ejection (LVEF) but with a significant body radiation (effective dose of 5,9 mSv for the injection of 850 Mbq of ^99mTc). The highly sensitive semi-conductor (CZT) cameras could allow decreasing the injected activity by a factor 3, similarly to that of myocardial perfusion imaging. Our study was aimed to determine whether the LVEF measurement provided by radionuclide ventriculography on the CZT D-SPECT camera is impacted by a 70% reduction in recorded counts.Materials and methodsAfter the in vivo labeling of red blood cells with 850 MBq of ^99mTc, 49 patients completed a conventional 2D recording (Conv-2D) on Anger camera followed by a 3D recording on the D-SPECT camera (3D-100%). The CZT recordings of all projections were subsequently shortened to 30% of their initial durations (3D-30%) in order to assess the LVEF measured with a 70% reduction in recorded counts.ResultsMean LVEF values were 62.7 ± 11.1% on Conv-2D and higher on both 3D-100% (66.8 ± 14.8%, P < 0.001) and 3D-30% (66.3 ± 15.7%, P < 0.001). The correlation coefficients with the LVEF determined with the reference Conv-2D method were equivalents for 3D-100% (r² = 0.73) and 3D-30% (r² = 0.70) and with a similar level of overestimation for the highest LEVF values.ConclusionA 70% reduction in recorded counts does not significantly impact the LVEF measured with radionuclide ventriculography on the CZT D-SPECT camera. These values are coherent with those obtained with the reference 2D method but with a clear overestimation for the highest LVEF values.     

Étude de l’impact d’une correction d’atténuation par tomodensitométrie en scintigraphie myocardique

Myocardial perfusion SPECT is a routine for the assessment of patients with coronary artery disease (CAD). However, attenuation artifacts may decrease the specificity of the test. These artifacts can be corrected with an attenuation correction. We prospectively included 70 patients who underwent myocardial perfusion SPECT with (IRAC) and without (IRNC) attenuation correction using transmission CT imaging integrated in the acquisition system in patients with low prevalence of CAD. Automatic quantitative analysis with summed stress score (SSS) and rest (SRS) and summed difference score (SDS) was used as interpretation criteria. The results showed a specificity of 80% for IRAC and 56% for IRNC, a positive predictive value of 40% for IRAC and 23% for IRNC, without any significant change in sensitivity. An unpaired t-test showed no significant difference between the overall population and one where an artifact was corrected for heart rate and breath rate during the acquisition effort, the body mass index, chest and abdomen circumferences, and the ratio of these two parameters. Attenuation correction significantly improves the specificity of myocardial scintigraphy with no significant difference in sensitivity. The majority of corrections were for artifacts from the inferior wall in men. There is no correlation between the anthropomorphic and physiological parameters and the occurrence of an artifact of attenuation corrected with CT data.