Température et plasticité du chromatisme de la coquille chez le mollusque pulmoné Helix aspersa

Phenotypic plasticity of shell pigmentation in the land snail Helix aspersa was investigated with the help of image processing followed by pixel counting for each colour present on the shell. Thus, the use of three different growth temperatures under artificial conditions showed, for the two subspecies considered, a continuous colour gradient from red to dark of the shell banding. Darker pigmentation characterized low temperatures while red bands were related to the higher temperature (25 °C). No interpretable difference appeared between the two forms.     

Le cancer radio-induit,le kangourou,et le petit lapin. Ou « la déclinaison radiobiologique du mythe de la Licorne Rose »

The linear no-threshold (LNT) model, which has become a dogma in its own right, leads to affirming the existence of the harmfulness of low doses of ionizing radiation as long as their harmlessness could not be demonstrated. It seems important to understand how we came to make dogmatic a scientifically “non-theory”. We propose in this article, after having shown how much RLSS stems from a myth and not from a scientific approach, to expose its origins and genesis, essential to the understanding of its current character of so-called incontestable truth, then to illustrate the worrying practical and epistemological consequences that this reference to RLSS entails. We rely for this on the critical analysis of some of the epidemiological studies that claim to demonstrate or confirm it.     

Influence du muscle deltoïde sur la courbure du corps de l’humérus chez les hommes modernes et les Néandertaliens

When observed in medial view, the humeral diaphysis shows two main types of curvature. It can be either more or less regularly distributed along the bone, or distally deported. Both types are about equally represented among modern humans, while the “regular” type largely prevails in Neandertals. Our hypothesis is that the distal curvature is the resultant of the action of the triceps brachial that “pulls” the bone in the posterior direction and of the deltoid that, in some cases, would be powerful enough to “straighten” the superior part of the diaphysis. Our results indicate that, in modern humans, bones with a distal curvature are indeed more frequent in males and on the right side and that their deltoid tuberosity is on average wider, more developed and more prominent as compared to bones with a regular curvature. This suggests a stronger solicitation of the deltoid muscle associated to this morphology. The high percentage of humeri showing a regular curvature observed in Neandertals would therefore be explainable by the fact that their deltoid tuberosity is averagely narrow, poorly developed and forming a weak prominence which likely attests of a moderate activity of this muscle in most of them.     

Rôle modeste du citrate comme transporteur d'acétyl-CoA chez l'animal vivant

2,4-(14) C-Citrate incorporated to a far greater extent than 1,5-(14) C-citrate into liver, carcass or adipose tissue fatty acids of living mice. This finding excludes the possibility that the acetyl units emerge from the mitochondria in the form of citrate.     

Communication interventriculaire avec défaillance cardiaque chez le nouveau-né et le nourrisson: Evaluation du traitement médical

Twenty-seven infants with ventricular septal defects and in cardiac failure were followed regularly under medical treatment for an average period of 17 months. The diagnosis was proved in all cases by cardiac catheterization.At the end of the follow-up period, the patients could be classified as follows: Sixteen patients showed no change in their cardiovascular status, and six had signs of pulmonary infundibular stenosis. One child had died from bronchopneumonia. Another was classified as having probable functional closure of the defect. Finally, three other children, because of failure of medical treatment, underwent banding of the pulmonary artery. One died during the operation.It is concluded that the great majority of patients with ventricular septal defects and cardiac failure can be carried successfully under medical management until the age at which corrective surgery is feasible. Palliative procedures which in themselves carry a fairly high mortality risk should be used only as a last resort.     

Développementin vitro de la lignée germinale foetale mâle chez le rat, la souris et l’homme

The key role of the foetal germ cell line in the reproductive capacity of the adult has been known for a long time. More recently, the observed increase in male reproductive disorders such as the decline of sperm count and quality and the increased incidence of testicular cancer has been postulated to be due to alterations of foetal and neonatal testicular development in response to increasing environmental pollution. However, few tools are available to study foetal and neonatal germ cell line development and the effects of physiological or toxic substances on this process. The authors have developed an organ culture system in which foetal or neonatal testis is grown on a filter floating on a synthetic medium free of serum, hormones or biological factors. This study, using rats and mice, first compared the long-term morphological and functional development of Sertoli and germ cells in thisin vivo system. In rats, these cells developed normally over a period of two weeksin vitro. Fewer cells were produced thanin vivo, but a similar level of differentiated function was observed. Germ cells, which are difficult to maintainin vitro, resumed mitosis after a quiescent period, at the same time asin vivo. Similar results were obtained with mouse fetuses, but this model was less efficient. This culture model can be used to study post-natal development of the germ cell lineage in testes derived from foetuses on the last day of foetal life and invalidated for P63, that do not survive after birth. This gene was found to be involved in the regulation of germ apoptosis which resumes after birth in the mouse. Lastly, this model applied to the human species (from 6 to 12 weeks of gestation) showed that testicular architecture and germ cells can be maintained for 4 days with better efficiency at younger stages than at older stages. p]In conclusion, testicular architecture and intercellular communications are sufficiently preserved to sustain gametogenesisin vitro with no added factors. This method is potentially useful to study the effects of various factors, particularly xenobiotics.     

Contribution a l'étude du parasitisme chez le Dentale

Sans résumé     

Etude des fluctuations annuelles des copépodes et du phytoplancton dans la manche et le golfe de gascogne par la méthode d'analyse de la variance et du coefficient de correlation

2275 samples have been collected with the Continuous Plankton Recorder of Hardy at a standard depth of 10 meteres in the English Channel and the Bay of Biscay between 1958–1965. Biological as well as statistical analyses have been carried out to provide data on annual fluctuations of 34 species of copepods and phytoplankton. Methods of analysis of variance and the correlation coefficient analysis were used for this purpose. The results are presented in the form of triangular matrices showing the annual fluctuations of species in the different areas considered and the relationship between different species in each area. These methods allowed us to define separate groups of species that could be called annual communities.

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Extrait d'une thèse de Doctorat en Oceanographie biologique, soutenue à la faculté des Sciences de Paris le 19 décembre 1967. Ce travail a été subventionné par the Office of Naval Research, Department of the United States Navy en vertu du contrat No 62558-3612.

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Extrait d'une thèse de Doctorat en Oceanographie biologique, soutenue à la faculté des Sciences de Paris le 19 décembre 1967. Ce travail a été subventionné par the Office of Naval Research, Department of the United States Navy en vertu du contrat No 62558-3612.     

La cholécystite et la cholélithiase chez l'enfant

Cholecystitis and cholelithiasis in children would appear to be a rare surgical finding; however, the authors have encountered 15 cases. Although in approximately half the children with this condition the symptomatology is sufficient to draw attention to the biliary tract, in the other half the presence of periumbilical or right lower quadrant abdominal tenderness can easily be misleading. Only by considering the use of cholecystography will one be in a position to make a diagnosis of cholelithiasis in these latter cases.Among the possible causally associated factors in the adult, sex (female) and obesity alone may be applicable in children. Cholecystectomy with peroperative cholangiography is the treatment of choice, even though the occurrence of migratory calculi in the common bile duct is exceptional.