Automation et robotique préanalytique points forts et zones sensibles d’un nouveau développement

Cet article est la première partie d’un dossier relatif à l’Automation et à la Robotique. Elle est plus théorique. Elle sera suivie d’une deuxième partie pratique, réalisée en lien avec des installations effectives.     

La prédation informative : vers un nouveau concept d’espèce

We distinguish two types of predations: the predation of matter-energy equals the food chain, and the informative predation is the capture of the information brought by the sexual partners. The cell or parent consumes energy and matter to grow, multiply and produce offspring. A fixed amount of resources is divided by the number of organisms, so individual growth and numerical multiplication are limited by depletion resources of the environment. Inversely, fertilization does not destroy information, but instead produces news. The information is multiplied by the number of partners and children, since each fertilization gives rise to a new genome following a combinatorial process that continues without exhaustion. The egg does not swallow the sperm to feed, but exchange good food for quality information. With the discovery of sex, that is, 1.5 Ga ago, life added soft predation to hard predation, i.e. information production within each species to matter-energy flow between species. Replicative and informative structures are subject to two competing biological constraints: replicative fidelity promotes proliferation, but limits adaptive evolution. On the contrary, the offspring of a couple obviously cannot be a copy of both partners, they are a new production, a re-production. Sexual recombination allows the exponential enrichment of the genetic diversity, thus promoting indefinite adaptive and evolutionary capacities. Evolutionary history illustrates this: the bacteria proliferate but have remained at the first purely nutritive stage in which most of the sensory functions, mobility, defense, and feeding have experienced almost no significant novelty in three billion years. Another world appeared with the sexual management of information. Sexual reproduction actually combines two functions: multiplicative by “vertical transfer” and informative by “horizontal transfer”. This distinction is very common: polypus – medusa alternations, parasite multiplication cycles, the lytochal and deuterotochal parthenogenesis of aphids, and the innumerable para- and pseudo-sexual strategies of plants opportunistically combine the two modes of asexual replication and sexual combination. However, for the majority of animals and multicellular plants that produce many gametes, numerical proliferation by descendants and informative diversity by sexuality are mutually implicated, for example in the seed. The true discovery of eukaryotes may not be the “true nucleus”, as their name implies, but an orderly informative function. The field of recombinations circumscribes a class of partners genetically compatible with each other, each simultaneously prey and predator of the DNA of the other. The mythical Maxwell demon capable of tracing entropy by sorting molecules according to their state does exist: each mate is the other's Maxwell's demon. While a sexless bacterium is simply divided into two cells, two sexual parents work together to produce a single offspring a time. Added to this are the burdens involved in meiosis and crossing-over, cellular diploidy, and mating. Sex produces an information gain that is paid for by a cost of energy-material, and this barter must be fair to survive. The domains of sexual intercourse are very diverse: uniparental reproduction, alternation of asexual proliferation and sexual information, self-fertilization, endogamy, exogamy, panmixis, diffuse or structured polymorphism, fertile or sterile hybridization, horizontal transfers. Each species is a recombination field between two domains, cloning and hybridization. Multiplicative descent and informative fertilization are organically distinct, but selectively associated: the information produced by the parents’ sexuality favors the predation of matter-energy and therefore the proliferation of offspring, and this proliferation in turn favors the sexed producers of information. The equation specific to each species is: enough energy to proliferate, enough information to diversify. Alternatively, two other reproductive modes obtain or transmit less information at lower cost: not enough recombinations = repetitive clonal proliferation, and too many recombinations = disordered hybridization. But these marginal modes have poor prospects, as the model of the species is successfully attractive. Better discriminate to better inform. In bacteria, the exchanged and incorporated DNA segments are directly identified by the parity of the complementary strands, which determines simultaneously the similarity, the offspring, and the pairing. In eukaryotes, on the contrary, somatic growth and germinal information are segregated. During speciation, adaptive information is compacted, delocalized, codified and published to inform the species about its own state: the prezygotic relationship governs viable mating. Under the effect of sexual selection, the runaway and the reinforcement of the characters related to courtship testifies to their identifying function, which explains the paradox of the singularity and luxuriance of the sexual hypertrophies. The speciation discretizes a balanced recombination field and validates the informative relations. The species is without degree. Mates of a species recognize each other quickly and well because the logic of coding disengages from the ecological game of adaptations. The system of mate recognition has a function of cohesion and its regularity allows the adaptations of the less regular being, it is neither elitist nor normative, it is subjected neither to a level of aptitudes, nor to sexual performances, but permissive; it protects the variability and polymorphism. Two mutually irreducible relationships triggered the debate between the taxonomists who support the phyletic definition of the species by the descendance, and the proponents of the definition by interfertility. Such a taxonomic disagreement is not insurmountable, but the issue is deeper than taxonomic concepts, because these concepts relate to two different modes of evolution. According to the phyletic model, each species is a lineage passively isolated by external circumstances; on the contrary, in the sexual model each species is actively produced by an internal process of adjustment between replicative costs and informative gains. Each species develops a solution of the equation that matches material-energy expenditures with informative gains. A species concept based on a lasting relationship between these two quantities or on the limits of certain values or their equilibrium is therefore legitimate. It is this equilibrium that all couples resolve, without our formulation being as clearly as biology desires and as physics demands. Energy expenditures and informative gains in sexuality are almost impossible to measure, yet observation and experience allow an approximate ranking of the energy/information ratio. For example, endogamy is more economical, but less diversifying than exogamy, polymorphism increases information, the reinforcement of sexual isolation limits the rate of unproductive fertilization, between neighboring species hybridization allows certain genetic contributions, etc. A closed species evolves naturally towards another just as closed. On the contrary, the artificial transfer of DNA opens the species. The natural boundaries that isolate the species are easily trespassed as energy costs and constraints of sexual recognition are easily controlled; and the perspectives of manipulations are visible, whereas natural selection never anticipates and thus works blindly. Informative, artificially directed predation stimulates the evolution of species.     

Scintigraphie osseuse et déficit en IGF1 : présentation d’un cas clinique

Growth delay in adults with GH (growth hormone) or insulin-like growth factor 1 (IGF1) deficiency is often associated to low bone mineral density (BMD), osteoporosis and a higher risk of fractures (Tritos et al., 2011 [1]; Wüster et al., 2001 [2]; Bex et Bouillon, 2003 [3]). However to date, the risk of fractures in children with GH or IGF1 deficiency is not clearly evaluated (Högler and Shaw, 2010 [4]). This is the case of a young woman aged 21, with a syndrome including a severe mental, growth and weight retardation (–4 SD), facial dysmorphism and partial epilepsy, who recently presented walking and muscle strength loss, without history of trauma. Bone scan revealed several hot spots related to cortical bone fractures and biological data showed an IGF1 deficiency. Through this case, we discuss the role played by GH and IGF1 in bone growth, and the basic procedures to follow in children when measuring BMD with dual absorptiometry X ray technique (DXA).     

Scintigraphie myocardique et séquelles de myocardite : présentation d’un cas clinique

Acute and subacute myocarditis are well-defined pathological entities but it is often difficult to identify them because their clinical expression is variable and the diagnosis is histological showing myocardial inflammation associated with degeneration and/or necrosis. Often symptoms are similar to those of acute pericarditis with “chest-crushing” pain that mimics myocardial infarction and prompts practitioners to request angiography, especially when there are cardiovascular risk factors. We report the case of a 61-year-old patient with neither cardiac history nor cardiovascular risk factor who consulted for a long and self-limited atypical chest pain with normal clinical examination and electrocardiogram. Myocardial perfusion scintigraphy showed a non-reversible photopenic area suspected of being a nontransmural necrosis or an artifact. The discovery of inferolateral hypokinesis of left ventricle on echocardiography led to perform a coronary angiography which was finally normal. Cardiac MRI allowed to diagnose scars of a previous episode of myocarditis.     

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.     

Services d’éducation préscolaire et comportements agressifs : un rôle de prévention pour les familles vulnérables

Context

Physical violence is a significant problem in health terms and for society as a whole. Many studies have shown that socio-economic indicators such as poverty and poor parental educational attainment are associated with an increased risk of difficulties in social adjustment of the child. The hypothesis of this study was that the pre-school educational services (PES) could help to prevent the development of physical aggression (PA) in the children of vulnerable families, and that this would depend on the age at which the child first had access to the service.

Methods

Identification of children presenting with a pattern of increased PA between 17 and 60 months of age, taken from a representative sample of children born in Quebec (N = 1691). We took into consideration the educational level of the mother and the age at which the child started to receive PES. We examined the association of these factors with the PA group to which the child belonged, while controlling against several other family characteristics which are associated with PES and PA.

Results

The children of mothers with a low level of educational attainment (no secondary school qualification) were less likely to have received PES than the others. Those who had received such attention had a considerably reduced risk of displaying a behaviour pattern of increased PA. The results of multiple logistic regression analysis revealed that the PES reduced the risk of high PA, especially if the child was exposed to the service before the age of 9 months (d = ?0.62; SD = 0.24; 95% CI: ?1.09 to ?0.16; odds ratio = 0.20; 95% CI: 0.05–0.9). Children whose mothers had obtained a secondary school diploma were at reduced risk of high PA. For them, the PES did not represent an additional protective factor.

Interpretation

PES directed towards children of poorly educated mothers might reduce considerably the risk of chronic physical aggression, especially if initiated soon after birth. As those children who aremost likely to benefit from PES are the least likely to receive it, it is necessary to put special measures in place to direct this sort of service towards at risk families.     

Développement et évaluation d’un algorithme de segmentation automatisée des ventricules gauche et droit sur des images ciné d’IRM

An automated segmentation of the left and right ventricles on cine MRI is presented here. A rectangular region around the object of interest is defined in the original image, a morphological filter is then applied that combines openings and closings on connected sets, providing an image with homogeneous regions, which is finally segmented with an active contour model. The algorithm was tested on two databases with an expert's segmentation on the ventricles. One of the databases was provided by the Multicentric Initiative for a Platform of Evaluation in Cardiac Imaging (IMPEIC) group. Results show a very satisfactory correlation between the area (given in mm²) of expertise (x) and the area of automated segmentation (y) of the left ventricle (y = 1.00x + 8.6, r = 0.99). First results on the right ventricle show more than 83% similarity. The systolic phase proved to be more difficult to segment, which could be taken into consideration by introducing time regularization criteria in the algorithm.     

Développement d’un dispositif expérimental ultrasonore pour le largage ciblé et contrôlé d’une chimiothérapie encapsulée

Applying ultrasound on drug-loaded sonosensitive liposomes offers new possibilities for treating cancer. In vitro experiments were performed in the present study to define an index of inertial cavitation which could be used to monitor the delivery of drugs. This index could also be used to assess the sonosensitivity of new formulations of liposomes. Experiments were then carried out in rats bearing subcutaneous abdominal tumors. Based on pharmacokinetic and biodistribution studies, a period of 48 hours was chosen between the injection of the liposomes and the exposure to ultrasound. At the injected doses, liposomes slowed down significantly the tumor development. Ultrasound combined with liposomes seemed to contribute to the tumor control. However, the important efficacy of liposomes alone and the eventual weak interactions with ultrasound prevent to guarantee that the effect of ultrasound is significant.     

ForenSeek: un programme de simulation du développement des insectes nécrophages dédié à l’entomologie médico-légale

L’entomologie médico-légale repose sur l’utilisation des insectes nécrophages pour estimer le moment de la mort dans le cadre d’enquêtes judiciaires et permet dans certains cas de préciser les circonstances du décès. Cette technique repose sur des bases scientifiques solides et est désormais couramment utilisée en France comme à l’étranger dans le cadre d’affaires criminelles. Le projet ForenSeek est un outil informatique d’aide à la décision, dédié à la réalisation de simulations et d’expertises en entomologie médico-légale. Le cæur de ce programme est un modèle de comportement et de développement des larves de diptères nécrophages basé sur un système multi-agents (SMA). Ce procédé permet de modéliser des comportements de groupes complexes à partir de données individuelles simples, et est done particulièrement bien adapté à l’étude des populations d’insectes. De plus, les résultats de ce modèle sont destines à être traités automatiquement pour en extraire des informations sur la pertinence de chaque simulation, et ainsi estimer de manière automatisée et avec précision l’intervalle post-mortem (IPM).     

Une nouvelle observation d’une métastase testiculaire d’un adénocarcinome prostatique: Aspects diagnostiques et éthiopathogéniques

Testicular metastases from prostatic adenocarcinoma are rare. They are often asymptomatic and diagnosed incidentally or at autopsy after orchidectomy in more advanced stages of the disease. The authors report a new case and review the diagnosis and aetiopathogenesis of these metastases. A 67-year-old patient with prostatic adenocarcinoma presented with painless right testicular mass for two months with no inflammatory signs. Germ cell tumour serum markers were negative. Scrotal ultrasound showed a large testicular tumour measuring 7×4×3cm. Histological examination revealed a solid non-differentiated tumour, not suggestive of primary testicular tumour. The immunohistochemical panel confirmed the prostate as the primary site due to the positivity of cytokeratins, PSA and PSAP and the negativity of classical markers of germ cell tumours. Testicular metastases from prostatic adenocarcinoma are rare, but their incidence is currently on the increase. They are often asymptomatic and discovered after pulpectomy. This diagnosis must be considered in the case of a testicular mass in patients over the age of 50 with a history of prostatic adenocarcinoma. The diagnosis was established after orchidectomy by histological examination and immunohistochemical tests.     

Caractérisation de souches cultivées d'un nouveau champignon comestible: Stropharia rugoso-annulata. II. Anatomie,développement mycélien et fructification

To establish a performing production strategy for the edible mushroom Stropharia rugoso-annulata, investigations on anatomy and physiological characteristics of the basidiomycete were carried out. Scanning electron microscopy analysis of Stropharia strains revealed no significant morphological differences. Spore germination was only obtained in the presence of growing mycelium. On the basis of the influence of temperature on the growth rate of Stropharia strains, three groups were defined without relation to phenotypic classification. Moreover, every strain exhibited a higher growth rate at 25 °C, and residual growth was observed above 35 °C The pH of the medium did not affect mycelium development. Regardless of the initial pH value, after 2 weeks of mycelium growth, the pH was established at a value close to 3.5. However, no acidic compounds were detected in this medium. A preliminary cultivation trial indicated that carpophore formation is strongly affected by spawn run time.     

Croissance et développement deCystoseira (Phaeophycea-Fucales) méditerranéens

Resume 1. Comparaison du comportement et de l'évolution au cours d'une année de quelques pieds âgés et de quelques embryons deCystoseira méditerranéens (principalementC. mediterranea Sauvageau 1912) cultivés parallèlement d'une part en pleine mer, d'autre part au laboratoire en milieu artificiel ou en aquarium.2. En pleine mer, l'évolution des échantillons âgés se déroule normalement. En aquarium, la chute des rameaux de printemps et la formation des rameaux d'automne sont d'autant plus précoces que l'éclairement est plus faible.3. Le développement et la croissance des embryons sont à peu près semblables en mer et au laboratoire, mais les «feuilles» caractéristiques apparaissent beaucoup plus tôt sur les individus cultivés en milieu artificiel. Les jeunes plantules nées en automne évoluent beaucoup plus rapidement que les plantules de printemps.

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Wachstum und Entwicklung mediterraner Cystoseiren (Phaeophyceae-Fucales). Kulturversuche im Meer

Kurzfassung Etwa ein Jahr lang wurde die Entwicklung mediterranerCystoseira-Arten (hauptsächlich vonC. mediterranea) verglichen, die im freien Meer und im Aquarium bzw. im Laboratorium aufwuchsen. Es zeigte sich, daß Pflanzen vom natürlichen Standort auf dem Versuchsstand im freien Meer normal weitergediehen. Im Aquarium treiben — vermutlich wegen des schwächeren Lichtgenusses — die Frühjahrssprosse zeitiger aus, und die Herbstzweige erscheinen früher. Aus Eiern kultivierte Keimlinge entwickeln sich in künstlichen Nährmedien zunächst schneller, doch gleicht sich der Größenunterschied nach dem Umsetzen in das Meer oder Aquarium nach 6 Monaten aus. Die charakteristischen Blätter erschienen aber bei den im Laboratorium kultivierten Pflanzen früher als bei den Vergleichspflanzen im Meer. In einer Aufzucht aus Herbsteiern erscheinen die Blätter bereits im Februar, also zur gleichen Zeit wie bei den um ein halbes Jahr älteren Kulturen.

     

Le Mésolithique. Continuité et développement métaphysique

The Mesolithic is a fascinating period, where ancient traditions are tilting towards a new paradigm. Many changes can be recognised without being able to establish a real split with the Palaeolithic. Far from being just a bridge towards the Neolithic, the Mesolithic is truly a new and stable metaphysical structure. In our article, we are interested in the structural mechanisms by which Palaeolithic metaphysics slides towards the Mesolithic, where the individual occupies a central role.